WorldWideScience

Sample records for solubility pollution plumes

  1. Characterization of redox conditions in pollution plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Bjerg, Poul Løgstrup; Banwart, Steven A.

    2000-01-01

    Evalution of redox conditions in groundwater pollution plumes is often a prerequisite for understanding the behviour of the pollutants in the plume and for selecting remediation approaches. Measuring of redox conditions in pollution plumes is, however, a fairly recent issue and yet relative few...

  2. Atmospheric ventilation corridors and coefficients for pollution plume ...

    African Journals Online (AJOL)

    This study presents a comparative investigation of atmospheric ventilation corridors and coefficients for gaseous pollution plume released from an isolated industrial facility into the ambient air of the host community in Ile-Ife suburb, southwest Nigeria. For the months of September to December in the year 2012 and 2013, ...

  3. Chemical composition of aerosol measurements in the air pollution plume during KORUS-AQ

    Science.gov (United States)

    Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Park, J. S.; Soo, C. J.; Kim, J.; Park, S.; Lee, Y.; Desyaterik, Y.; Collett, J. L., Jr.; Lee, T.

    2017-12-01

    The Korean peninsula is a great place to study different sources of the aerosols: urban, rural and marine. In addition, Seoul is one of the large metropolitan areas in the world and has a variety of sources because half of the Korean population lives in Seoul, which comprises only 12% of the country's area. To understand the chemical composition of aerosol form long-range transport and local sources better, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on an airborne platform (NASA DC-8 aircraft). The HR-ToF-AMS is capable of measuring non-refractory size resolved chemical composition of submicron particle(NR-PM1) in the air pollution plume, including mass concentration of organic carbon, nitrate, sulfate, and ammonium with 10 seconds time resolution. The measurements were performed twenty times research flight for understanding characteristic of the air pollution from May to June, 2016 on the South Korean peninsula during KORUS-AQ 2016 campaign. The scientific goal of this study is to characterize aerosol chemical properties and mass concentration in order to understand the role of the long-range transport from northeast Asia to South Korea, and influence of the local sources. To brief, organics dominated during all of flights. Also, organics and nitrate were dominant around energy industrial complex near by Taean, South Korea. The presentation will provide an overview of the composition of NR-PM1 measured in air pollution plumes, and deliver detail information about width, depth and spatial distribution of the pollutant in the air pollution plumes. The results of this study will provide high temporal and spatial resolved details on the air pollution plumes, which are valuable input parameters of aerosol properties for the current air quality models.

  4. Aircraft measurements over Europe of an air pollution plume from Southeast Asia – aerosol and chemical characterization

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2007-01-01

    Full Text Available An air pollution plume from Southern and Eastern Asia, including regions in India and China, was predicted by the FLEXPART particle dispersion model to arrive in the upper troposphere over Europe on 24–25 March 2006. According to the model, the plume was exported from Southeast Asia six days earlier, transported into the upper troposphere by a warm conveyor belt, and travelled to Europe in a fast zonal flow. This is confirmed by the retrievals of carbon monoxide (CO from AIRS satellite measurements, which are in excellent agreement with the model results over the entire transport history. The research aircraft DLR Falcon was sent into this plume west of Spain on 24 March and over Southern Europe on 25 March. On both days, the pollution plume was found close to the predicted locations and, thus, the measurements taken allowed the first detailed characterization of the aerosol content and chemical composition of an anthropogenic pollution plume after a nearly hemispheric transport event. The mixing ratios of CO, reactive nitrogen (NOy and ozone (O3 measured in the Asian plume were all clearly elevated over a background that was itself likely elevated by Asian emissions: CO by 17–34 ppbv on average (maximum 60 ppbv and O3 by 2–9 ppbv (maximum 22 ppbv. Positive correlations existed between these species, and a ΔO3/ΔCO slope of 0.25 shows that ozone was formed in this plume, albeit with moderate efficiency. Nucleation mode and Aitken particles were suppressed in the Asian plume, whereas accumulation mode aerosols were strongly elevated and correlated with CO. The suppression of the nucleation mode was likely due to the large pre-existing aerosol surface of the transported larger particles. Super-micron particles, likely desert dust, were found in part of the Asian pollution plume and also in surrounding cleaner air. The aerosol light absorption coefficient was enhanced in the plume (average values for individual plume encounters 0.25–0

  5. Pollutant Plume Dispersion in the Atmospheric Boundary Layer over Idealized Urban Roughness

    Science.gov (United States)

    Wong, Colman C. C.; Liu, Chun-Ho

    2013-05-01

    The Gaussian model of plume dispersion is commonly used for pollutant concentration estimates. However, its major parameters, dispersion coefficients, barely account for terrain configuration and surface roughness. Large-scale roughness elements (e.g. buildings in urban areas) can substantially modify the ground features together with the pollutant transport in the atmospheric boundary layer over urban roughness (also known as the urban boundary layer, UBL). This study is thus conceived to investigate how urban roughness affects the flow structure and vertical dispersion coefficient in the UBL. Large-eddy simulation (LES) is carried out to examine the plume dispersion from a ground-level pollutant (area) source over idealized street canyons for cross flows in neutral stratification. A range of building-height-to-street-width (aspect) ratios, covering the regimes of skimming flow, wake interference, and isolated roughness, is employed to control the surface roughness. Apart from the widely used aerodynamic resistance or roughness function, the friction factor is another suitable parameter that measures the drag imposed by urban roughness quantitatively. Previous results from laboratory experiments and mathematical modelling also support the aforementioned approach for both two- and three-dimensional roughness elements. Comparing the UBL plume behaviour, the LES results show that the pollutant dispersion strongly depends on the friction factor. Empirical studies reveal that the vertical dispersion coefficient increases with increasing friction factor in the skimming flow regime (lower resistance) but is more uniform in the regimes of wake interference and isolated roughness (higher resistance). Hence, it is proposed that the friction factor and flow regimes could be adopted concurrently for pollutant concentration estimate in the UBL over urban street canyons of different roughness.

  6. Pollutant Plume Dispersion over Hypothetical Urban Areas based on Wind Tunnel Measurements

    Science.gov (United States)

    Mo, Ziwei; Liu, Chun-Ho

    2017-04-01

    Gaussian plume model is commonly adopted for pollutant concentration prediction in the atmospheric boundary layer (ABL). However, it has a number of limitations being applied to pollutant dispersion over complex land-surface morphology. In this study, the friction factor (f), as a measure of aerodynamic resistance induced by rough surfaces in the engineering community, was proposed to parameterize the vertical dispersion coefficient (σz) in the Gaussian model. A series of wind tunnel experiments were carried out to verify the mathematical hypothesis and to characterize plume dispersion as a function of surface roughness as well. Hypothetical urban areas, which were assembled in the form of idealized street canyons of different aspect (building-height-to-street-width) ratios (AR = 1/2, 1/4, 1/8 and 1/12), were fabricated by aligning identical square aluminum bars at different separation apart in cross flows. Pollutant emitted from a ground-level line source into the turbulent boundary layer (TBL) was simulated using water vapour generated by ultrasonic atomizer. The humidity and the velocity (mean and fluctuating components) were measured, respectively, by humidity sensors and hot-wire anemometry (HWA) with X-wire probes in streamwise and vertical directions. Wind tunnel results showed that the pollutant concentration exhibits the conventional Gaussian distribution, suggesting the feasibility of using water vapour as a passive scalar in wind tunnel experiments. The friction factor increased with decreasing aspect ratios (widening the building separation). It was peaked at AR = 1/8 and decreased thereafter. Besides, a positive correlation between σz/xn (x is the distance from the pollutant source) and f1/4 (correlation coefficient r2 = 0.61) was observed, formulating the basic parameterization of plume dispersion over urban areas.

  7. On the Pollutant Plume Dispersion in the Urban Canopy Layer over 2D Idealized Street Canyons: A Large-Eddy Simulation Approach

    Science.gov (United States)

    Wong, Colman C. C.; Liu, Chun-Ho

    2010-05-01

    Anthropogenic emissions are the major sources of air pollutants in urban areas. To improve the air quality in dense and mega cities, a simple but reliable prediction method is necessary. In the last five decades, the Gaussian pollutant plume model has been widely used for the estimation of air pollutant distribution in the atmospheric boundary layer (ABL) in an operational manner. Whereas, it was originally designed for rural areas with rather open and flat terrain. The recirculating flows below the urban canopy layer substantially modify the near-ground urban wind environment and so does the pollutant distribution. Though the plume height and dispersion are often adjusted empirically, the accuracy of applying the Gaussian pollutant plume model in urban areas, of which the bottom of the flow domain consists of numerous inhomogeneous buildings, is unclear. To elucidate the flow and pollutant transport, as well as to demystify the uncertainty of employing the Gaussian pollutant plume model over urban roughness, this study was performed to examine how the Gaussian-shape pollutant plume in the urban canopy layer is modified by the idealized two-dimensional (2D) street canyons at the bottom of the ABL. The specific objective is to develop a parameterization so that the geometric effects of urban morphology on the operational pollutant plume dispersion models could be taken into account. Because atmospheric turbulence is the major means of pollutant removal from street canyons to the ABL, the large-eddy simulation (LES) was adopted to calculate explicitly the flows and pollutant transport in the urban canopy layer. The subgrid-scale (SGS) turbulent kinetic energy (TKE) conservation was used to model the SGS processes in the incompressible, isothermal conditions. The computational domain consists of 12 identical idealized street canyons of unity aspect ratio which were placed evenly in the streamwise direction. Periodic boundary conditions (BCs) for the flow were applied

  8. In-Situ and Remote-Sensing Data Fusion Using Machine Learning Techniques to Infer Urban and Fire Related Pollution Plumes

    Science.gov (United States)

    Russell, P. B.; Segal-Rozenhaimer, M.; Schmid, B.; Redemann, J.; Livingston, J. M.; Flynn, C.J.; Johnson, R. R.; Dunagan, S. E.; Shinozuka, Y.; Kacenelenbogen, M.; hide

    2014-01-01

    Airmass type characterization is key in understanding the relative contribution of various emission sources to atmospheric composition and air quality and can be useful in bottom-up model validation and emission inventories. However, classification of pollution plumes from space is often not trivial. Sub-orbital campaigns, such as SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) give us a unique opportunity to study atmospheric composition in detail, by using a vast suite of in-situ instruments for the detection of trace gases and aerosols. These measurements allow identification of spatial and temporal atmospheric composition changes due to various pollution plumes resulting from urban, biogenic and smoke emissions. Nevertheless, to transfer the knowledge gathered from such campaigns into a global spatial and temporal context, there is a need to develop workflow that can be applicable to measurements from space. In this work we rely on sub-orbital in-situ and total column remote sensing measurements of various pollution plumes taken aboard the NASA DC-8 during 2013 SEAC4RS campaign, linking them through a neural-network (NN) algorithm to allow inference of pollution plume types by input of columnar aerosol and trace-gas measurements. In particular, we use the 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) airborne measurements of wavelength dependent aerosol optical depth (AOD), particle size proxies, O3, NO2 and water vapor to classify different pollution plumes. Our method relies on assigning a-priori ground-truth labeling to the various plumes, which include urban pollution, different fire types (i.e. forest and agriculture) and fire stage (i.e. fresh and aged) using cluster analysis of aerosol and trace-gases in-situ and auxiliary (e.g. trajectory) data and the training of a NN scheme to fit the best prediction parameters using 4STAR measurements as input. We explore our

  9. Modelling of transport and biogeochemical processes in pollution plumes: Vejen landfill, Denmark

    DEFF Research Database (Denmark)

    Brun, A.; Engesgaard, Peter Knudegaard; Christensen, Thomas Højlund

    2002-01-01

    A biogeochemical transport code is used to simulate leachate attenuation. biogeochemical processes. and development of redox zones in a pollution plume downstream of the Vejen landfill in Denmark. Calibration of the degradation parameters resulted in a good agreement with the observed distribution...

  10. Study on spraying water soluble resin to reduce pollution for Fukushima daiichi NPP accident

    International Nuclear Information System (INIS)

    Zhang Qiong; Guo Ruiping; Zhang Chunming; Han Fujuan; Hua Jie; Zhang Jiankui

    2012-01-01

    After Fukushima nuclear accident, Tokyo electric power company used the method of spraying water soluble resin synthesis at the scene of the accident, to restrain and control the spread of the radioactive dust, by forming consolidation layer in pollution area surface. This paper briefly introduced the accident, motivation of spraying water soluble resin, spraying range and implementation process. According to the relevant report on Fukushima nuclear accident, the effect of spraying water soluble resin for reducing pollution was analyzed. The mechanism of reducing pollution for water soluble resin and the application prospect were discussed. Spraying water soluble resin for fixing radioactive dust has reasonable reducing pollution effect. It is worth to use as reference and study in China. (authors)

  11. Satellite Remote Sensing Detection of Coastal Pollution in Southern California: Stormwater Runoff and Wastewater Plumes

    Science.gov (United States)

    Trinh, R. C.; Holt, B.; Gierach, M.

    2016-02-01

    Coastal pollution poses a major health and environmental hazard, not only for beach goers and coastal communities but for marine organisms as well. Stormwater runoff is the largest source of environmental pollution in coastal waters of the Southern California Bight (SCB) and is of great concern in increasingly urbanized areas. Buoyant wastewater plumes also pose a marine environmental risk. In this study we provide a comprehensive overview of satellite remote sensing capabilities in detecting buoyant coastal pollutants in the form of stormwater runoff and wastewater effluent. The SCB is the final destination of four major urban rivers that act as channels for runoff and pollution during and after rainstorms. We analyzed and compared sea surface roughness data from various Synthetic Aperture Radar (SAR) instruments to ocean color data from the Moderate Imaging System (MODIS) sensor on board the Aqua satellite and correlated the results with existing environmental data in order to create a climatology of naturally occurring stormwater plumes in coastal waters after rain events, from 1992 to 2014 from four major rivers in the area. Heat maps of the primary extent of stormwater plumes were constructed to specify areas that may be subject to the greatest risk of coastal contamination. In conjunction with our efforts to monitor coastal pollution and validate the abilities of satellite remote sensing, a recent Fall 2015 wastewater diversion from the City of Los Angeles Hyperion Treatment Plant (HTP) provided the opportunity to apply these remote sensing methodologies of plume detection to wastewater. During maintenance of their 5-mile long outfall pipe, wastewater is diverted to a shorter outfall pipe that terminates 1-mile offshore and in shallower waters. Sea surface temperature (SST), chlorophyll-a (chl-a) fluorescence, remote sensing reflectance and particulate backscatter signatures were analyzed from MODIS. Terra-ASTER and Landsat-8 thermal infrared data were also

  12. Pitfalls with the use of enhancement ratios or normalized excess mixing ratios measured in plumes to characterize pollution sources and aging

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2013-08-01

    Full Text Available Normalized excess mixing ratios (NEMRs, also known as enhancement ratios, are a common way to characterize plumes of pollution in atmospheric research. As single-source pollutant plumes disperse in the atmosphere, they are diluted by mixing with the adjacent background air. Changes in the composition of this background air can cause large changes to the NEMR that is subsequently measured by remote-sensing, airborne, or ground-based instruments. This scenario is common when boundary layer plumes enter the free troposphere and could also impact long-range transport or plumes near the top of the troposphere. We provide a context for these issues and an example showing that neglect of this effect could lead to serious errors in data interpretation.

  13. Meteorology of the Southern Global Plume: African and South American Fires Pollute the South Pacific

    Science.gov (United States)

    Guo, Z.; Chatfield, R. B.

    1999-01-01

    An immense global plume of CO meanders widely around the world in the Southern Hemisphere. It arises over Southern America and Africa and flows eastward. The first emissions are in tropical Brazil, and the plume circulates around the world to South America again. The plume was largely unexpected until there were aircraft studies made in NASA's Pacific Exploratory Mission - Tropics (Part A). This paper describes the meteorology of the Global Plume, as our simulation, with a synoptic model adapted to global transport, reveals it with a tracer-CO simulation. The observations and their simulation require a particular set of conditions of pollutant accumulation, cumulonimbus venting with required strengths at a narrow range of altitude. Additionally, a particular subtropical conduction region, over the Indian Ocean, Australia, and the westeRNmost South Pacific, relatively free of storms, appears to be a key part of the mechanism. These conclusions are the results of a synoptic reconstruction of the PEMT-A period, September- October, 1996.

  14. Characterization of redox conditions in groundwater contaminant plumes

    Science.gov (United States)

    Christensen, Thomas H.; Bjerg, Poul L.; Banwart, Steven A.; Jakobsen, Rasmus; Heron, Gorm; Albrechtsen, Hans-Jørgen

    2000-10-01

    Evaluation of redox conditions in groundwater pollution plumes is often a prerequisite for understanding the behaviour of the pollutants in the plume and for selecting remediation approaches. Measuring of redox conditions in pollution plumes is, however, a fairly recent issue and yet relative few cases have been reported. No standardised or generally accepted approach exists. Slow electrode kinetics and the common lack of internal equilibrium of redox processes in pollution plumes make, with a few exceptions, direct electrochemical measurement and rigorous interpretation of redox potentials dubious, if not erroneous. Several other approaches have been used in addressing redox conditions in pollution plumes: redox-sensitive compounds in groundwater samples, hydrogen concentrations in groundwater, concentrations of volatile fatty acids in groundwater, sediment characteristics and microbial tools, such as MPN counts, PLFA biomarkers and redox bioassays. This paper reviews the principles behind the different approaches, summarizes methods used and evaluates the approaches based on the experience from the reported applications.

  15. Aircraft measurements over Europe of an air pollution plume from Southeast Asia ? aerosol and chemical characterization

    OpenAIRE

    Stohl , A.; Forster , C.; Huntrieser , H.; Mannstein , H.; Mcmillan , W. W.; Petzold , A.; Schlager , H.; Weinzierl , B.

    2006-01-01

    An air pollution plume from Southern and Eastern Asia, including regions in India and China, was predicted by the FLEXPART particle dispersion model to arrive in the upper troposphere over Europe on 24–25 March 2006. According to the model, the plume was exported from Southeast Asia only six days earlier, transported into the upper troposphere by a warm conveyor belt, and travelled to Europe in a fast zonal flow. This is confirmed by the retrievals of carbon monoxide (CO) from AIRS sate...

  16. Identification and assessment of water pollution as a consequence of a leachate plume migration from a municipal landfill site (Tucumán, Argentina).

    Science.gov (United States)

    Fernández, Diego S; Puchulu, María E; Georgieff, Sergio M

    2014-06-01

    Landfills constitute potential sources of different pollutants that could generate human health and environmental problems. While some landfills currently work under the protection of a bottom liner with leachate collection, it was demonstrated that migration could take place even yet with these cautions. The purpose of this paper is to assess the pollution caused by a leachate plume from a municipal landfill that is affecting both groundwater and surface waters. The research was carried out at Pacará Pintado landfill in northwestern Argentina. Analysis of water samples indicates that leachate is affecting groundwater under the landfill area and an abandoned river channel hydraulically connected. In the center of the landfill area, the plume is anoxic and sulfate, nitrate, iron and manganese reduction zones were identified. Leachate plume presented high concentration of organic matter, Fe, Mn, NH(4)(+), Cl(-) and Cr reaching an extension of 900 m. The presence of a leachate plume in a landfill site with a single liner system implies that the use of this groundwater pollution control method alone is not enough especially if permeable sediments are present below.

  17. Fate of organic contaminants in the redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Samples from 75 sample locations in a landfill leachate pollution plume reveal a significant disappearance of specific organic compounds (SOC's) within the first 100 m of the plume. Only the herbicide Mecoprop® (MCPP) migrates further. Since sorption and dilution cannot account for the decreasing...... concentrations, degradation is considered to be the governing process. Non-volatile organic carbon shows a corresponding fate probably acting as a substrate for the microbial processes. The first 20 m of the plume are methanogenic/sulfidogenic, judged on the chemistry of the groundwater, followed...... by a significant ferrogenic zone exhibiting a substantial capacity to degrade the SOC's. The presence of intermediary products (here an oxidized camphor compound) supports the concept of degradation within the ferrogenic zone. This investigation draws the attention to the significant natural attenuation of organic...

  18. Mapping Pollution Plumes in Areas Impacted by Hurricane Katrina With Imaging Spectroscopy

    Science.gov (United States)

    Swayze, G. A.; Furlong, E. T.; Livo, K. E.

    2007-12-01

    can be used to identify plume composition on a regional scale than this information would help emergency personnel prioritize evacuations, help government agencies formulate cleanup strategies, and help ecologists assess the potential damage to wetlands and wildlife. This work could be the start of a new application of hyperspectral data for world-wide monitoring of spills from space-based imaging spectrometers. AVIRIS data used to test our method were corrected for solar flux, atmospheric absorptions, and scattering using the Atmospheric CORrection Now (ACORN) radiative transfer algorithm and residual artifacts were removed using ground spectra of a concrete runway at the Gulfport Airport in Mississippi. The resulting apparent reflectance data were mapped for spectral signatures of pollution plumes and results will be presented.

  19. Formation of secondary organic aerosol in the Paris pollution plume and its impact on surrounding regions

    Science.gov (United States)

    Zhang, Q. J.; Beekmann, M.; Freney, E.; Sellegri, K.; Pichon, J. M.; Schwarzenboeck, A.; Colomb, A.; Bourrianne, T.; Michoud, V.; Borbon, A.

    2015-12-01

    Secondary pollutants such as ozone, secondary inorganic aerosol, and secondary organic aerosol formed in the plumes of megacities can affect regional air quality. In the framework of the FP7/EU MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) project, an intensive campaign was launched in the greater Paris region in July 2009. The major objective was to quantify different sources of organic aerosol (OA) within a megacity and in its plume. In this study, we use airborne measurements aboard the French ATR-42 aircraft to evaluate the regional chemistry-transport model CHIMERE within and downwind of the Paris region. Two mechanisms of secondary OA (SOA) formation are used, both including SOA formation from oxidation and chemical aging of primary semivolatile and intermediate volatility organic compounds (SI-SOA) in the volatility basis set (VBS) framework. As for SOA formed from traditional VOC (volatile organic compound) precursors (traditional SOA), one applies chemical aging in the VBS framework adopting different SOA yields for high- and low-NOx environments, while another applies a single-step oxidation scheme without chemical aging. Two emission inventories are used for discussion of emission uncertainties. The slopes of the airborne OA levels versus Ox (i.e., O3 + NO2) show SOA formation normalized with respect to photochemical activity and are used for specific evaluation of the OA scheme in the model. The simulated slopes were overestimated slightly by factors of 1.1, 1.7 and 1.3 with respect to those observed for the three airborne measurements, when the most realistic "high-NOx" yields for traditional SOA formation in the VBS scheme are used in the model. In addition, these slopes are relatively stable from one day to another, which suggests that they are characteristic for the given megacity plume environment. The configuration with increased primary

  20. Aircraft-Based measurement of the physico-chemical evolution of atmospheric aerosols in the air pollution plume over a megacity and a remote area

    Science.gov (United States)

    Park, J. S.; Lee, T.; Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Kim, J.; Park, S.; Collett, J. L., Jr.

    2017-12-01

    Aerosols influence climate change directly (scattering and absorption) and indirectly (cloud condensation nuclei), also adverse health effects. The Korean peninsula is a great place to study different sources of the aerosols: urban, rural and marine. In addition, Seoul is one of the large metropolitan areas in the world and has a variety of sources because half of the Korean population lives in Seoul, which comprises only 12% of the country's area. To understand the physico-chemical evolution of atmospheric aerosols in the air pollution plume over a megacity and a remote area, an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on an airborne platform (NASA DC-8 and Beechcraft King Air) in June, 2015 and May-June, 2016 during MAPS-Seoul and KORUS-AQ campaigns, respectively, in Korea. The HR-ToF-AMS is capable of measuring non-refractory size resolved chemical composition of submicron particle (NR-PM1). NR-PM1 includes mass concentration of organics, nitrate, sulfate, and ammonium with 10 seconds time resolution. Organics was dominated species in aerosol during all of flights. Organics and nitrate were dominant around energy industrial complex near by Taean, South Korea. The presentation will provide an overview of the composition of NR-PM1 measured in air pollution plumes, and deliver detail information about width, depth and spatial distribution of the pollutant in the air pollution plumes. The results of this study will provide high temporal and spatial resolved details on the air pollution plumes, which are valuable input parameters of aerosol properties for the current air quality models.

  1. Study of the mixing and ageing of polluted plumes from major West Africa cities

    Science.gov (United States)

    Tocquer, Flore; Mari, Céline; Leriche, Maud; Dacciwa Team

    2017-04-01

    Massive economic and population growth, fast urbanization in megacities along the Guinea Coast, would triple anthropogenic emissions by 2030 (Knippertz et al., 2015). Impacts of the rapid increase of atmospheric pollutants on weather and climate in this region are largely unstudied due to a lack of observations. The DACCIWA (Dynamics-aerosol-chemistry-cloud interactions in West Africa) project carried out an important airborne measurements campaign in June-July 2016 together with ground-based observations in urban and remote sites. Urban and industrial, biogenic dominated environment, dust and biomass burning air masses, ship plumes and flaring emissions were sampled successfully. The goal of this work is to investigate the transport and ageing of anthropogenic emissions from major West African megacities during boreal summer. For this purpose, the coupled atmosphere-chemistry mesoscale model Méso-NH was run at kilometric scale and results were compared with in-situ meteorological and chemical data. The study focuses on 06-07-08 July 2016. Three research aircrafts operated over the coastal region sampling downwind pollution from Lomé and Accra and biogenic emissions further inland. Preliminary simulation results will be presented to understand the mixing between and ageing of cities plumes during the post-onset period of the campaign.

  2. East Asian SO2 pollution plume over Europe – Part 2: Evolution and potential impact

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-07-01

    Full Text Available We report on the first observation-based case study of an aged East Asian anthropogenic SO2 pollution plume over Europe. Our airborne measurements in that plume detected highly elevated SO2 mole fractions (up to 900 pmol/mol between about 5000 and 7000 m altitude. Here, we focus on investigations of the origin, dispersion, evolution, conversion, and potential impact of the observed excess SO2. In particular, we investigate SO2 conversion to gas-phase sulfuric acid and sulfuric acid aerosols. Our FLEXPART and LAGRANTO model simulations, along with additional trace gas measurements, suggest that the plume originated from East Asian fossil fuel combustion sources and, 8–7 days prior to its arrival over Europe, ascended over the coast region of central East Asia to 9000 m altitude, probably in a cyclonic system with an associated warm conveyor belt. During this initial plume ascent a substantial fraction of the initially available SO2 must have escaped from removal by cloud processes. Hereafter, while mostly descending slowly, the plume experienced advection across the North Pacific, North America and the North Atlantic. During its upper troposphere travel, clouds were absent in and above the plume and OH-induced gas-phase conversion of SO2 to gas-phase sulfuric acid (GSA was operative, followed by GSA nucleation and condensation leading to sulfuric acid aerosol formation and growth. Our AEROFOR model simulations indicate that numerous large sulfuric acid aerosol particles were formed, which at least tempora-rily, caused substantial horizontal visibility degradation, and which have the potential to act as water vapor condensation nuclei in liquid water cloud formation, already at water vapor supersaturations as low as about 0.1%. Our AEROFOR model simulations also indicate that those fossil fuel combustion generated soot particles, which have survived cloud induced removal during the initial plume ascent, have experienced extensive H2SO4/H2O

  3. Simulating Fine-Scale Marine Pollution Plumes for Autonomous Robotic Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Muhammad Fahad

    2018-05-01

    Full Text Available Marine plumes exhibit characteristics such as intermittency, sinuous structure, shape and flow field coherency, and a time varying concentration profile. Due to the lack of experimental quantification of these characteristics for marine plumes, existing work often assumes marine plumes exhibit behavior similar to aerial plumes and are commonly modeled by filament based Lagrangian models. Our previous field experiments with Rhodamine dye plumes at Makai Research Pier at Oahu, Hawaii revealed that marine plumes show similar characteristics to aerial plumes qualitatively, but quantitatively they are disparate. Based on the field data collected, this paper presents a calibrated Eulerian plume model that exhibits the qualitative and quantitative characteristics exhibited by experimentally generated marine plumes. We propose a modified model with an intermittent source, and implement it in a Robot Operating System (ROS based simulator. Concentration time series of stationary sampling points and dynamic sampling points across cross-sections and plume fronts are collected and analyzed for statistical parameters of the simulated plume. These parameters are then compared with statistical parameters from experimentally generated plumes. The comparison validates that the simulated plumes exhibit fine-scale qualitative and quantitative characteristics similar to experimental plumes. The ROS plume simulator facilitates future evaluations of environmental monitoring strategies by marine robots, and is made available for community use.

  4. East Asian SO2 pollution plume over Europe – Part 1: Airborne trace gas measurements and source identification by particle dispersion model simulations

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2009-07-01

    Full Text Available A large SO2-rich pollution plume of East Asian origin was detected by aircraft based CIMS (Chemical Ionization Mass Spectrometry measurements at 3–7.5 km altitude over the North Atlantic. The measurements, which took place on 3 May 2006 aboard of the German research aircraft Falcon, were part of the INTEX-B (Intercontinental Chemical Transport Experiment-B campaign. Additional trace gases (NO, NOy, CO, H2O were measured and used for comparison and source identification. The atmospheric SO2 mole fraction was markedly increased inside the plume and reached up to 900 pmol/mol. Accompanying lagrangian FLEXPART particle dispersion model simulations indicate that the probed pollution plume originated at low altitudes from densely populated and industrialized regions of East Asia, primarily China, about 8–12 days prior to the measurements.

  5. CCN activation of fumed silica aerosols mixed with soluble pollutants

    Science.gov (United States)

    Dalirian, M.; Keskinen, H.; Ahlm, L.; Ylisirniö, A.; Romakkaniemi, S.; Laaksonen, A.; Virtanen, A.; Riipinen, I.

    2014-09-01

    Particle-water interactions of completely soluble or insoluble particles are fairly well understood but less is known of aerosols consisting of mixtures of soluble and insoluble components. In this study, laboratory measurements were performed to investigate cloud condensation nuclei (CCN) activity of silica particles coated with ammonium sulphate (a salt), sucrose (a sugar) and bovine serum albumin known as BSA (a protein). In addition, the agglomerated structure of the silica particles was investigated by estimating the surface equivalent diameter based on measurements with a Differential Mobility Analyzer (DMA) and an Aerosol Particle Mass Analyzer (APM). By using the surface equivalent diameter the non-sphericity of the particles containing silica was accounted for when estimating CCN activation. Furthermore, characterizing critical supersaturations of particles consisting of pure soluble on insoluble compounds using existing frameworks showed that the CCN activation of single component particles was in good agreement with Köhler and adsorption theory based models when the agglomerated structure was accounted for. For mixed particles the CCN activation was governed by the soluble components, and the soluble fraction varied considerably with particle size for our wet-generated aerosols. Our results confirm the hypothesis that knowing the soluble fraction is the key parameter needed for describing the CCN activation of mixed aerosols, and highlight the importance of controlled coating techniques for acquiring a detailed understanding of the CCN activation of atmospheric insoluble particles mixed with soluble pollutants.

  6. The effect of water solubles on Kelvin effects of the Maritime Polluted ...

    African Journals Online (AJOL)

    In this work microphysical properties of Maritime Polluted aerosols wereextracted from Optical Properties of Aerosols and Clouds (OPAC) after varying the concentrations of water soluble at five different levels. The analytical expressions for the changes in the equilibrium relative humidity (RH), effective radii, effective ...

  7. Turbulent forces within river plumes affect spread

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-08-01

    When rivers drain into oceans through narrow mouths, hydraulic forces squeeze the river water into buoyant plumes that are clearly visible in satellite images. Worldwide, river plumes not only disperse freshwater, sediments, and nutrients but also spread pollutants and organisms from estuaries into the open ocean. In the United States, the Columbia River—the largest river by volume draining into the Pacific Ocean from North America—generates a plume at its mouth that transports juvenile salmon and other fish into the ocean. Clearly, the behavior and spread of river plumes, such as the Columbia River plume, affect the nation's fishing industry as well as the global economy.

  8. Water resources research program. Pollution of coastal waters off Chicago by sinking plumes from the Indiana Harbor Canal

    International Nuclear Information System (INIS)

    Harrison, W.; McCown, D.L.; Raphaelian, L.A.; Saunders, K.D.

    1977-12-01

    On March 2, 1977, during sinking-plume conditions, a portion of the water of the Indiana Harbor Canal (IHC) was injected with samarium and rhodamine-dye tags and a section of the IHC's surface was covered with simulated oily waste tagged with dysprosium. Water samples were taken downcurrent, over a 54-hr period, from a vessel and from the raw-water streams from the intakes at Chicago's South Water Filtration Plant (SWFP). Bottom currents and water temperatures were measured almost continuously at four Lake Michigan stations located between the IHC and the SWFP. Unequivocal evidence is presented for transport of the tagged IHC water and oily waste to the SWFP's intakes. Organic contaminants from the IHC were present in trace concentrations in the SWFP's raw water. A model for the transport and mixing of the entire IHC effluent, for the environmental conditions during the experiment, indicates a minimum dilution of 4 in the plume offshore of the SWFP and, for the assumed plume trajectory, values of 5 x 10 2 and 10 5 at the shore and crib intakes, respectively. A similar model applied to the experimental situation of tagged effluent showed reasonable agreement with measurements. Analysis of historical data indicates that the worst-case pollution event that might be experienced at the SWFP, assuming constant pollutant loading in the IHC, would be due to 24 hr of northwest wind followed by a 3.0-in. (7.6 cm), 24-hr rainfall that coincides with 3.0 x 10 6 m of total wind movement from the southerly quadrants

  9. The possible use of soluble humic substances for remediation of heavy metal polluted soils

    DEFF Research Database (Denmark)

    Borggaard, Ole K.; Jensen, Julie Katrine; Holm, Peter Engelund

    2008-01-01

    Polluted soil is a common and serious environmental problem. While reliable methods exist for cleaning soil contaminated by organic compounds through degradation, remediation of heavy metal polluted soils awaits an appropriate solution. This is because heavy metals are nondegradable and generally....... Therefore, the potential of soluble natural humic substances (HS) to extract heavy metals from contaminated soils is tested as an environmental friendly substitute for EDTA. A strongly polluted urban soil and a moderately polluted agricultural soil were extracted at neutral pH in batch mode by three HS...... extraction. Heavy metal extraction with dissolved HS is compared with EDTA at the same concentration and sequential extraction has been performed to identify extracted pools. The results indicate a clear potential of using HS solutions for remediation of heavy metal polluted soils, which is fortunate...

  10. Lagrangian analysis of low altitude anthropogenic plume processing across the North Atlantic

    Directory of Open Access Journals (Sweden)

    E. Real

    2008-12-01

    Full Text Available The photochemical evolution of an anthropogenic plume from the New-York/Boston region during its transport at low altitudes over the North Atlantic to the European west coast has been studied using a Lagrangian framework. This plume, originally strongly polluted, was sampled by research aircraft just off the North American east coast on 3 successive days, and then 3 days downwind off the west coast of Ireland where another aircraft re-sampled a weakly polluted plume. Changes in trace gas concentrations during transport are reproduced using a photochemical trajectory model including deposition and mixing effects. Chemical and wet deposition processing dominated the evolution of all pollutants in the plume. The mean net photochemical O3 production is estimated to be −5 ppbv/day leading to low O3 by the time the plume reached Europe. Model runs with no wet deposition of HNO3 predicted much lower average net destruction of −1 ppbv/day O3, arising from increased levels of NOx via photolysis of HNO3. This indicates that wet deposition of HNO3 is indirectly responsible for 80% of the net destruction of ozone during plume transport. If the plume had not encountered precipitation, it would have reached Europe with O3 concentrations of up to 80 to 90 ppbv and CO between 120 and 140 ppbv. Photochemical destruction also played a more important role than mixing in the evolution of plume CO due to high levels of O3 and water vapour showing that CO cannot always be used as a tracer for polluted air masses, especially in plumes transported at low altitudes. The results also show that, in this case, an increase in O3/CO slopes can be attributed to photochemical destruction of CO and not to photochemical O3 production as is often assumed.

  11. Atmospheric deposition of beryllium in Central Europe: comparison of soluble and insoluble fractions in rime and snow across a pollution gradient.

    Science.gov (United States)

    Bohdalkova, Leona; Novak, Martin; Voldrichova, Petra; Prechova, Eva; Veselovsky, Frantisek; Erbanova, Lucie; Krachler, Michael; Komarek, Arnost; Mikova, Jitka

    2012-11-15

    Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For three consecutive winters (2009-2011), we measured Be concentrations in horizontal deposition (rime) and vertical deposition (snow) at 10 remote mountain-top locations in the Czech Republic, Central Europe. Beryllium was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9ng·L(-1)). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble>vertical dry deposition soluble>horizontal deposition soluble>vertical wet deposition insoluble>vertical wet deposition soluble>horizontal deposition insoluble. The average contributions of these Be forms to total deposition were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeast were more Be-polluted than the rest of the country with sources of pollution in industrial Silesia. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Atmospheric deposition of beryllium in Central Europe: Comparison of soluble and insoluble fractions in rime and snow across a pollution gradient

    International Nuclear Information System (INIS)

    Bohdalkova, Leona; Novak, Martin; Voldrichova, Petra; Prechova, Eva; Veselovsky, Frantisek; Erbanova, Lucie; Krachler, Michael; Komarek, Arnost; Mikova, Jitka

    2012-01-01

    Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For three consecutive winters (2009–2011), we measured Be concentrations in horizontal deposition (rime) and vertical deposition (snow) at 10 remote mountain-top locations in the Czech Republic, Central Europe. Beryllium was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9 ng·L −1 ). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble > vertical dry deposition soluble > horizontal deposition soluble > vertical wet deposition insoluble > vertical wet deposition soluble > horizontal deposition insoluble. The average contributions of these Be forms to total deposition were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeast were more Be-polluted than the rest of the country with sources of pollution in industrial Silesia. -- Highlights: ► We measured Be concentrations in rime and snow in the Czech Republic. ► Soluble Be concentrations in rime were 7 times higher than in snow. ► 34% of total Be deposition occurred in the form of soluble (bioavailable) Be. ► Dry-deposited fluxes dominated Be inputs. ► Soluble Be concentrations only rarely exceeded 30 ng·L −1 .

  13. The maximum ground level concentration of air pollutant and the effect of plume rise on concentration estimates

    International Nuclear Information System (INIS)

    Mayhoub, A.B.; Azzam, A.

    1991-01-01

    The emission of an air pollutant from an elevated point source according to Gaussian plume model has been presented. An elementary theoretical treatment for both the highest possible ground-level concentration and the downwind distance at which this maximum occurs for different stability classes has been constructed. The effective height release modification was taken into consideration. An illustrative case study, namely, the emission from the research reactor in Inchas, has been studied. The results of these analytical treatments and of the derived semi-empirical formulae are discussed and presented in few illustrative diagrams

  14. Biogeochemistry of landfill leachate plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Kjeldsen, Peter; Bjerg, Poul Løgstrup

    2001-01-01

    are relatively narrow and do not in terms of width exceed the width of the landfill. The concept of redox zones being present in the plume has been confirmed by the reported composition of the leachate contaminated groundwater at several landfills and constitutes an important framework for understanding...... the behavior of the contaminants in the plume as the leachate migrates away from the landfill. Diverse microbial communities have been identified in leachate plumes and are believed to be responsible for the redox processes. Dissolved organic C in the leachate, although it appears to be only slowly degradable...... to be subject to anaerobic oxidation, but the mechanisms are not yet understood. Heavy metals do not seem to constitute a significant pollution problem at landfills, partly because the heavy metal concentrations in the leachate often are low, and partly because of strong attenuation by sorption...

  15. Tracking stormwater discharge plumes and water quality of the Tijuana River with multispectral aerial imagery

    Science.gov (United States)

    Svejkovsky, Jan; Nezlin, Nikolay P.; Mustain, Neomi M.; Kum, Jamie B.

    2010-04-01

    Spatial-temporal characteristics and environmental factors regulating the behavior of stormwater runoff from the Tijuana River in southern California were analyzed utilizing very high resolution aerial imagery, and time-coincident environmental and bacterial sampling data. Thirty nine multispectral aerial images with 2.1-m spatial resolution were collected after major rainstorms during 2003-2008. Utilizing differences in color reflectance characteristics, the ocean surface was classified into non-plume waters and three components of the runoff plume reflecting differences in age and suspended sediment concentrations. Tijuana River discharge rate was the primary factor regulating the size of the freshest plume component and its shorelong extensions to the north and south. Wave direction was found to affect the shorelong distribution of the shoreline-connected fresh plume components much more strongly than wind direction. Wave-driven sediment resuspension also significantly contributed to the size of the oldest plume component. Surf zone bacterial samples collected near the time of each image acquisition were used to evaluate the contamination characteristics of each plume component. The bacterial contamination of the freshest plume waters was very high (100% of surf zone samples exceeded California standards), but the oldest plume areas were heterogeneous, including both polluted and clean waters. The aerial imagery archive allowed study of river runoff characteristics on a plume component level, not previously done with coarser satellite images. Our findings suggest that high resolution imaging can quickly identify the spatial extents of the most polluted runoff but cannot be relied upon to always identify the entire polluted area. Our results also indicate that wave-driven transport is important in distributing the most contaminated plume areas along the shoreline.

  16. Modelling pollutants dispersion and plume rise from large hydrocarbon tank fires in neutrally stratified atmosphere

    Science.gov (United States)

    Argyropoulos, C. D.; Sideris, G. M.; Christolis, M. N.; Nivolianitou, Z.; Markatos, N. C.

    2010-02-01

    Petrochemical industries normally use storage tanks containing large amounts of flammable and hazardous substances. Therefore, the occurrence of a tank fire, such as the large industrial accident on 11th December 2005 at Buncefield Oil Storage Depots, is possible and usually leads to fire and explosions. Experience has shown that the continuous production of black smoke from these fires due to the toxic gases from the combustion process, presents a potential environmental and health problem that is difficult to assess. The goals of the present effort are to estimate the height of the smoke plume, the ground-level concentrations of the toxic pollutants (smoke, SO 2, CO, PAHs, VOCs) and to characterize risk zones by comparing the ground-level concentrations with existing safety limits. For the application of the numerical procedure developed, an external floating-roof tank has been selected with dimensions of 85 m diameter and 20 m height. Results are presented and discussed. It is concluded that for all scenarios considered, the ground-level concentrations of smoke, SO 2, CO, PAHs and VOCs do not exceed the safety limit of IDLH and there are no "death zones" due to the pollutant concentrations.

  17. Stormwater runoff plumes in the Southern California Bight: A comparison study with SAR and MODIS imagery.

    Science.gov (United States)

    Holt, Benjamin; Trinh, Rebecca; Gierach, Michelle M

    2017-05-15

    Stormwater runoff is the largest source of pollution in the Southern California Bight (SCB), resulting from untreated runoff and pollutants from urban watersheds entering the coastal waters after rainstorms. We make use of both satellite SAR and MODIS-Aqua ocean color imagery to examine two different components of runoff plumes, the surface slick and the sediment discharge. We expand on earlier satellite SAR studies by examining an extensive collection of multi-platform SAR imagery, spanning from 1992 to 2014, that provides a more comprehensive view of the plume surface slick characteristics, illustrated with distribution maps of the extent and flow direction of the plumes. The SAR-detected surface plumes are compared with coincident rain and runoff measurements, and with available measured shoreline fecal bacteria loads. We illustrate differences in the detection of SAR surface plumes with the sediment-related discharge plumes derived from MODIS imagery. A conceptual satellite stormwater runoff monitoring approach is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Turbulent Plume Dispersion over Two-dimensional Idealized Urban Street Canyons

    Science.gov (United States)

    Wong, C. C. C.; Liu, C. H.

    2012-04-01

    Human activities are the primary pollutant sources which degrade the living quality in the current era of dense and compact cities. A simple and reasonably accurate pollutant dispersion model is helpful to reduce pollutant concentrations in city or neighborhood scales by refining architectural design or urban planning. The conventional method to estimate the pollutant concentration from point/line sources is the Gaussian plume model using empirical dispersion coefficients. Its accuracy is pretty well for applying to rural areas. However, the dispersion coefficients only account for the atmospheric stability and streamwise distance that often overlook the roughness of urban surfaces. Large-scale buildings erected in urban areas significantly modify the surface roughness that in turn affects the pollutant transport in the urban canopy layer (UCL). We hypothesize that the aerodynamic resistance is another factor governing the dispersion coefficient in the UCL. This study is thus conceived to study the effects of urban roughness on pollutant dispersion coefficients and the plume behaviors. Large-eddy simulations (LESs) are carried out to examine the plume dispersion from a ground-level pollutant source over idealized 2D street canyons in neutral stratification. Computations with a wide range of aspect ratios (ARs), including skimming flow to isolated flow regimes, are conducted. The vertical profiles of pollutant distribution for different values of friction factor are compared that all reach a self-similar Gaussian shape. Preliminary results show that the pollutant dispersion is closely related to the friction factor. For relatively small roughness, the factors of dispersion coefficient vary linearly with the friction factor until the roughness is over a certain level. When the friction factor is large, its effect on the dispersion coefficient is less significant. Since the linear region covers at least one-third of the full range of friction factor in our empirical

  19. Aging of plumes from emission sources based on chamber simulation

    Science.gov (United States)

    Wang, X.; Deng, W.; Fang, Z.; Bernard, F.; Zhang, Y.; Yu, J.; Mellouki, A.; George, C.

    2017-12-01

    Study on atmospheric aging of plumes from emission sources is essential to understand their contribution to both secondary and primary pollutants occurring in the ambient air. Here we directly introduced vehicle exhaust, biomass burning plume, industrial solvents and cooking plumes into a smog chamber with 30 m3 fluorinated ethylene propylene (FEP) Teflon film reactor housed in a temperature-controlled enclosure, for characterizing primarily emitted air pollutants and for investigating secondarily formed products during photo-oxidation. Moreover, we also initiated study on the formation of secondary aerosols when gasoline vehicle exhaust is mixed with typical coal combustion pollutant SO2 or typical agricultural-related pollutant NH3. Formation of secondary organic aerosols (SOA) from typical solvent toluene was also investigated in ambient air matrix in comparison with purified air matrix. Main findings include: 1) Except for exhaust from idling gasoline vehicles, traditional precursor volatile organic compounds could only explain a very small fraction of SOA formed from vehicle exhaust, biomass burning or cooking plumes, suggesting knowledge gap in SOA precursors; 2) There is the need to re-think vehicle emission standards with a combined primary and/or secondary contribution of vehicle exhaust to PM2.5 or other secondary pollutants such as ozone; 3) When mixed with SO2, the gasoline vehicle exhaust revealed an increase of SOA production factor by 60-200% and meanwhile SO2 oxidation rates increased about a factor of 2.7; when the aged gasoline vehicle exhaust were mixing with NH3, both particle number and mass concentrations were increasing explosively. These phenomenons implied the complex interaction during aging of co-existing source emissions. 4) For typical combination of "tolune+SO2+NOx", when compared to chamber simulation with purified air as matrix, both SOA formation and SO2 oxidation were greatly enhanced under ambient air matrix, and the enhancement

  20. Dispersion of Chernobyl radioactive plume over Europe

    International Nuclear Information System (INIS)

    Albergel, A.

    1988-01-01

    A long-range pollutant transport and removal model, is used to analyse the Chernobyl radioactive plume dispersion over the Europe Continent. Model predictions are compared to field measurements of Cs-137 activity in the air from April 26th, to May 5th 1986 [fr

  1. Analysis of dissolved benzene plumes and methyl tertiary butyl ether (MTBE) plumes in ground water at leaking underground fuel tank (LUFT) sites

    International Nuclear Information System (INIS)

    Happel, A.M.; Rice, D.; Beckenbach, E.; Savalin, L.; Temko, H.; Rempel, R.; Dooher, B.

    1996-11-01

    The 1990 Clean Air Act Amendments mandate the addition of oxygenates to gasoline products to abate air pollution. Currently, many areas of the country utilize oxygenated or reformulated fuel containing 15- percent and I I-percent MTBE by volume, respectively. This increased use of MTBE in gasoline products has resulted in accidental point source releases of MTBE containing gasoline products to ground water. Recent studies have shown MTBE to be frequently detected in samples of shallow ground water from urban areas throughout the United States (Squillace et al., 1995). Knowledge of the subsurface fate and transport of MTBE in ground water at leaking underground fuel tank (LUFT) sites and the spatial extent of MTBE plumes is needed to address these releases. The goal of this research is to utilize data from a large number of LUFT sites to gain insights into the fate, transport, and spatial extent of MTBE plumes. Specific goals include defining the spatial configuration of dissolved MTBE plumes, evaluating plume stability or degradation over time, evaluating the impact of point source releases of MTBE to ground water, and attempting to identify the controlling factors influencing the magnitude and extent of the MTBE plumes. We are examining the relationships between dissolved TPH, BTEX, and MTBE plumes at LUFT sites using parallel approaches of best professional judgment and a computer-aided plume model fitting procedure to determine plume parameters. Here we present our initial results comparing dissolved benzene and MTBE plumes lengths, the statistical significance of these results, and configuration of benzene and MTBE plumes at individual LUFT sites

  2. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, Terry C.; Lopez-De-Victoria, Geralyne

    1994-01-01

    A method and system for enhancing the motility of microorganisms by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant.

  3. Applying tracer techniques to NPP liquid effluents for estimating the maximum concentration of soluble pollutants in a man-made canal

    International Nuclear Information System (INIS)

    Varlam, Carmen; Stefanescu, Ioan; Varlam, Mihai; Raceanu, Mircea; Enache, Adrian; Faurescu, Ionut; Patrascu, Vasile; Bucur, Cristina

    2006-01-01

    Full text: The possibility of a contamination agent being accidentally or intentionally spilled upstream from a water supply is a constant concern to those diverting and using water from a channel. A method of rapidly estimating the travel-time or dispersion is needed for pollution control or warning system on channels where data are scarce. Travel-time and mixing of water within a stream are basic streamflow characteristics needed in order to predict the rate of movement and dilution of pollutants that could be introduced in the stream. In this study we propose using tritiated liquid effluents from CANDU type nuclear power plant as a tracer, to study hydrodynamics on Danube-Black Sea Canal. This canal is ideal for this kind of study, because wastewater evacuations occur occasionally due to technical operations of nuclear power plant. Tritiated water can be used to simulate the transport and dispersion of solutes in Danube-Black Sea Canal because they have the same physical characteristics as the water. Measured tracer-response curves produced from injection of a known amount of soluble tracer provide an efficient method of obtaining the necessary data. This method can estimate: (1) the rate of movement of a solute through the canal reach: (2) the rate of peak attenuation concentration of a conservative solute in time; and (3) the length of time required for the solute plume to pass a point in the canal. This paper presents the mixing length calculation for particular conditions (lateral branch of the canal, and lateral injection of wastewater from the nuclear power plant). A study of published experimentally-obtained formulas was used to determine proper mixing length. Simultaneous measurements in different locations of the canal confirm the beginning of the experiment. Another result used in a further experiment concerns the tritium level along the Danube-Black Sea Canal. We measured tritium activity concentration in water sampled along the Canal between July

  4. Method of degrading pollutants in soil

    Science.gov (United States)

    Hazen, T.C.; Lopez-De-Victoria, G.

    1994-07-05

    Disclosed are a method and system for enhancing the motility of microorganisms. This is accomplished by placing an effective amount of chlorinated hydrocarbons, preferably chlorinated alkenes, and most preferably trichloroethylene in spaced relation to the microbes so that the surprisingly strong, monomodal, chemotactic response of the chlorinated hydrocarbon on subsurface microbes can draw the microbes away from or towards and into a substance, as desired. In remediation of groundwater pollution, for example, TCE can be injected into the plume to increase the population of microbes at the plume whereby the plume can be more quickly degraded. A TCE-degrading microbe, such as Welchia alkenophilia, can be used to degrade the TCE following the degradation of the original pollutant. 5 figures.

  5. Impact of mineral dust on nitrate, sulfate, and ozone in transpacific Asian pollution plumes

    Directory of Open Access Journals (Sweden)

    T. D. Fairlie

    2010-04-01

    Full Text Available We use a 3-D global chemical transport model (GEOS-Chem to interpret aircraft observations of nitrate and sulfate partitioning in transpacific dust plumes during the INTEX-B campaign of April–May 2006. The model includes explicit transport of size-resolved mineral dust and its alkalinity, nitrate, and sulfate content. The observations show that particulate nitrate is primarily associated with dust, sulfate is primarily associated with ammonium, and Asian dust remains alkaline across the Pacific. This can be reproduced in the model by using a reactive uptake coefficient for HNO3 on dust (γ(HNO3 ~10−3 much lower than commonly assumed in models and possibly reflecting limitation of uptake by dust dissolution. The model overestimates gas-phase HNO3 by a factor of 2–3, typical of previous model studies; we show that this cannot be corrected by uptake on dust. We find that the fraction of aerosol nitrate on dust in the model increases from ~30% in fresh Asian outflow to 80–90% over the Northeast Pacific, reflecting in part the volatilization of ammonium nitrate and the resulting transfer of nitrate to the dust. Consumption of dust alkalinity by uptake of acid gases in the model is slow relative to the lifetime of dust against deposition, so that dust does not acidify (at least not in the bulk. This limits the potential for dust iron released by acidification to become bio-available upon dust deposition. Observations in INTEX-B show no detectable ozone depletion in Asian dust plumes, consistent with the model. Uptake of HNO3 by dust, suppressing its recycling to NOx, reduces Asian pollution influence on US surface ozone in the model by 10–15% or up to 1 ppb.

  6. Stormwater Runoff Plumes in Southern California Detected with Satellite SAR and MODIS Imagery - Areas of Increased Contamination Risk

    Science.gov (United States)

    Trinh, R. C.; Holt, B.; Gierach, M.

    2016-12-01

    Coastal pollution poses both a major health and environmental hazard, not only for beachgoers and coastal communities, but for marine organisms as well. Stormwater runoff is the largest source of pollution in the coastal waters of the Southern California Bight (SCB). The SCB is the final destination of four major urban watersheds and associated rivers, Ballona Creek, the Los Angeles River, the San Gabriel River, and the Santa Ana River, which act as channels for runoff and pollution during and after episodic rainstorms. Previous studies of SCB water quality have made use of both fine resolution Synthetic Aperture Radar (SAR) imagery and wide-swath medium resolution optical "ocean color" imagery from SeaWiFS and MODIS. In this study, we expand on previous SAR efforts, compiling a more extensive collection of multi-sensor SAR data, spanning from 1992 to 2014, analyzing the surface slick component of stormwater plumes. We demonstrate the use of SAR data in early detection of coastal stormwater plumes, relating plume extent to cumulative river discharge, and shoreline fecal bacteria loads. Intensity maps of the primary extent and direction of plumes were created, identifying coastal areas that may be subject to the greatest risk of environmental contamination. Additionally, we illustrate the differences in the detection of SAR surface plumes with the sediment-related discharge plumes derived from MODIS ocean color imagery. Finally, we provide a concept for satellite monitoring of stormwater plumes, combining both optical and radar sensors, to be used to guide the collection of in situ water quality data and enhance the assessment of related beach closures.

  7. African biomass burning plumes over the Atlantic: aircraft based measurements and implications for H2SO4 and HNO3 mediated smoke particle activation

    Directory of Open Access Journals (Sweden)

    A. Dörnbrack

    2011-04-01

    Full Text Available Airborne measurements of trace gases and aerosol particles have been made in two aged biomass burning (BB plumes over the East Atlantic (Gulf of Guinea. The plumes originated from BB in the Southern-Hemisphere African savanna belt. On the day of our measurements (13 August 2006, the plumes had ages of about 10 days and were respectively located in the middle troposphere (MT at 3900–5500 m altitude and in the upper troposphere (UT at 10 800–11 200 m. Probably, the MT plume was lifted by dry convection and the UT plume was lifted by wet convection. In the more polluted MT-plume, numerous measured trace species had markedly elevated abundances, particularly SO2 (up to 1400 pmol mol−1, HNO3 (5000–8000 pmol mol−1 and smoke particles with diameters larger than 270 nm (up to 2000 cm−3. Our MT-plume measurements indicate that SO2 released by BB had not experienced significant loss by deposition and cloud processes but rather had experienced OH-induced conversion to gas-phase sulfuric acid. By contrast, a significant fraction of the released NOy had experienced loss, most likely as HNO3 by deposition. In the UT-plume, loss of NOy and SO2 was more pronounced compared to the MT-plume, probably due to cloud processes. Building on our measurements and accompanying model simulations, we have investigated trace gas transformations in the ageing and diluting plumes and their role in smoke particle processing and activation. Emphasis was placed upon the formation of sulfuric acid and ammonium nitrate, and their influence on the activation potential of smoke particles. Our model simulations reveal that, after 13 August, the lower plume traveled across the Atlantic and descended to 1300 m and hereafter ascended again. During the travel across the Atlantic, the soluble mass fraction of smoke particles and their mean diameter increased sufficiently to allow the processed smoke particles to act as water vapor condensation nuclei already at very low water

  8. Dispersion under low wind speed conditions using Gaussian Plume approach

    International Nuclear Information System (INIS)

    Rakesh, P.T.; Srinivas, C.V.; Baskaran, R.; Venkatesan, R.; Venkatraman, B.

    2018-01-01

    For radioactive dose computation due to atmospheric releases, dispersion models are essential requirement. For this purpose, Gaussian plume model (GPM) is used in the short range and advanced particle dispersion models are used in all ranges. In dispersion models, other than wind speed the most influential parameter which determines the fate of the pollutant is the turbulence diffusivity. In GPM the diffusivity is represented using empirical approach. Studies show that under low wind speed conditions, the existing diffusivity relationships are not adequate in estimating the diffusion. An important phenomenon that occurs during the low wind speed is the meandering motions. It is found that under meandering motions the extent of plume dispersion is more than the estimated value using conventional GPM and particle transport models. In this work a set of new turbulence parameters for the horizontal diffusion of the plume is suggested and using them in GPM, the plume is simulated and is compared against observation available from Hanford tracer release experiment

  9. Atmospheric pollutant outflow from southern Asia: a review

    Science.gov (United States)

    Lawrence, M. G.; Lelieveld, J.

    2010-11-01

    Southern Asia, extending from Pakistan and Afghanistan to Indonesia and Papua New Guinea, is one of the most heavily populated regions of the world. Biofuel and biomass burning play a disproportionately large role in the emissions of most key pollutant gases and aerosols there, in contrast to much of the rest of the Northern Hemisphere, where fossil fuel burning and industrial processes tend to dominate. This results in polluted air masses which are enriched in carbon-containing aerosols, carbon monoxide, and hydrocarbons. The outflow and long-distance transport of these polluted air masses is characterized by three distinct seasonal circulation patterns: the winter monsoon, the summer monsoon, and the monsoon transition periods. During winter, the near-surface flow is mostly northeasterly, and the regional pollution forms a thick haze layer in the lower troposphere which spreads out over millions of square km between southern Asia and the Intertropical Convergence Zone (ITCZ), located several degrees south of the equator over the Indian Ocean during this period. During summer, the heavy monsoon rains effectively remove soluble gases and aerosols. Less soluble species, on the other hand, are lifted to the upper troposphere in deep convective clouds, and are then transported away from the region by strong upper tropospheric winds, particularly towards northern Africa and the Mediterranean in the tropical easterly jet. Part of the pollution can reach the tropical tropopause layer, the gateway to the stratosphere. During the monsoon transition periods, the flow across the Indian Ocean is primarily zonal, and strong pollution plumes originating from both southeastern Asia and from Africa spread across the central Indian Ocean. This paper provides a review of the current state of knowledge based on the many observational and modeling studies over the last decades that have examined the southern Asian atmospheric pollutant outflow and its large scale effects. An outlook

  10. Heavy metals and organic pollutants in soils. Concentrations - sorption and solubility - effects on micro-organisms; Schwermetalle und organische Schadstoffe in Boeden. Gehalte - Sorption und Loeslichkeit - Wirkung auf Mikroorganismen

    Energy Technology Data Exchange (ETDEWEB)

    Welp, G.

    2000-07-01

    The thesis comprises six manuscripts published in different journals. Soil protection being the main theme the articles deal with different aspects that represent a necessary scientific basis of a risk assessment for polluted soils. The first step is to look at the total contents of different soil contaminants and to decide whether a pollution is given or not. In chapter II the contents of 18 elements in 335 soil samples of North Rhine-Westphalia are analysed, in order to determine groups of soil samples that are characterized by a certain range of element contents in connection with other common features (e.g., parent material, sampling region, specific source of pollution). The study bases on a detailed inspection of frequency distributions which are evaluated with a parametric method (assuming several single lognormal distributions) and with a nonparametric approach (Kemel density estimation). The latter method proved to be a useful tool to derive background concentrations for toxic elements in soils. It is necessary to differentiate between soluble (mobile, available) and insoluble (immobile, strongly adsorbed, precipitated) fractions of pollutants in soil. The sorption and solubility of pollutants in soils, therefore, is a second important parameter for an appropriate risk assessment. Four papers (chapter III-VI) deal with this aspect. In chapter III sorption and solubility of ten metals in four soil samples is studied. The quantity-intensity relations of eight metals [except Cr(III) and Fe(III)] are governed by sorption and complexation procecces and can be fitted by Freundlich isotherms. In three further papers sorption and solubility experiments with inorganic and organic toxicants are combined with microbial tests in order to detect effects on microorganisms in relation to soil properties. The large data set of about 500 dose-response curves was also used to examine the general reaction patterns of heterogeneous microbial populations under chemical stress

  11. Point Pollution Sources Dimensioning

    Directory of Open Access Journals (Sweden)

    Georgeta CUCULEANU

    2011-06-01

    Full Text Available In this paper a method for determining the main physical characteristics of the point pollution sources is presented. It can be used to find the main physical characteristics of them. The main physical characteristics of these sources are top inside source diameter and physical height. The top inside source diameter is calculated from gas flow-rate. For reckoning the physical height of the source one takes into account the relation given by the proportionality factor, defined as ratio between the plume rise and physical height of the source. The plume rise depends on the gas exit velocity and gas temperature. That relation is necessary for diminishing the environmental pollution when the production capacity of the plant varies, in comparison with the nominal one.

  12. Integrating wildfire plume rises within atmospheric transport models

    Science.gov (United States)

    Mallia, D. V.; Kochanski, A.; Wu, D.; Urbanski, S. P.; Krueger, S. K.; Lin, J. C.

    2016-12-01

    Wildfires can generate significant pyro-convection that is responsible for releasing pollutants, greenhouse gases, and trace species into the free troposphere, which are then transported a significant distance downwind from the fire. Oftentimes, atmospheric transport and chemistry models have a difficult time resolving the transport of smoke from these wildfires, primarily due to deficiencies in estimating the plume injection height, which has been highlighted in previous work as the most important aspect of simulating wildfire plume transport. As a result of the uncertainties associated with modeled wildfire plume rise, researchers face difficulties modeling the impacts of wildfire smoke on air quality and constraining fire emissions using inverse modeling techniques. Currently, several plume rise parameterizations exist that are able to determine the injection height of fire emissions; however, the success of these parameterizations has been mixed. With the advent of WRF-SFIRE, the wildfire plume rise and injection height can now be explicitly calculated using a fire spread model (SFIRE) that is dynamically linked with the atmosphere simulated by WRF. However, this model has only been tested on a limited basis due to computational costs. Here, we will test the performance of WRF-SFIRE in addition to several commonly adopted plume parameterizations (Freitas, Sofiev, and Briggs) for the 2013 Patch Springs (Utah) and 2012 Baker Canyon (Washington) fires, for both of which observations of plume rise heights are available. These plume rise techniques will then be incorporated within a Lagrangian atmospheric transport model (STILT) in order to simulate CO and CO2 concentrations during NASA's CARVE Earth Science Airborne Program over Alaska during the summer of 2012. Initial model results showed that STILT model simulations were unable to reproduce enhanced CO concentrations produced by Alaskan fires observed during 2012. Near-surface concentrations were drastically

  13. CALIOP-based Biomass Burning Smoke Plume Injection Height

    Science.gov (United States)

    Soja, A. J.; Choi, H. D.; Fairlie, T. D.; Pouliot, G.; Baker, K. R.; Winker, D. M.; Trepte, C. R.; Szykman, J.

    2017-12-01

    Carbon and aerosols are cycled between terrestrial and atmosphere environments during fire events, and these emissions have strong feedbacks to near-field weather, air quality, and longer-term climate systems. Fire severity and burned area are under the control of weather and climate, and fire emissions have the potential to alter numerous land and atmospheric processes that, in turn, feedback to and interact with climate systems (e.g., changes in patterns of precipitation, black/brown carbon deposition on ice/snow, alteration in landscape and atmospheric/cloud albedo). If plume injection height is incorrectly estimated, then the transport and deposition of those emissions will also be incorrect. The heights to which smoke is injected governs short- or long-range transport, which influences surface pollution, cloud interaction (altered albedo), and modifies patterns of precipitation (cloud condensation nuclei). We are working with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) science team and other stakeholder agencies, primarily the Environmental Protection Agency and regional partners, to generate a biomass burning (BB) plume injection height database using multiple platforms, sensors and models (CALIOP, MODIS, NOAA HMS, Langley Trajectory Model). These data have the capacity to provide enhanced smoke plume injection height parameterization in regional, national and international scientific and air quality models. Statistics that link fire behavior and weather to plume rise are crucial for verifying and enhancing plume rise parameterization in local-, regional- and global-scale models used for air quality, chemical transport and climate. Specifically, we will present: (1) a methodology that links BB injection height and CALIOP air parcels to specific fires; (2) the daily evolution of smoke plumes for specific fires; (3) plumes transport and deposited on the Greenland Ice Sheet; and (4) compare CALIOP-derived smoke plume injection

  14. Characterization of an old municipal landfill (Grindsted, Denmark) as a groundwater pollution source

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Grundtvig, Aase; Winther, Pia

    1998-01-01

    Investigations into the pollution of groundwater from old landfill have, in most cases, focused on delineating the pollution plume rather than on the landfill as a source of groundwater pollution. Landfills often cover large areas and spatial variations in leachate composition within the landfill...... may have great impact on the location of the main pollution plume in the downstream aquifer. The history of the Grindsted Landfill in Denmark was investigated using aerial photographs and interviews. On the basis of the aerial photographs, waste volume and age of the different areas of the landfill...

  15. Sulfur balance in power plant plumes: a critical review

    Science.gov (United States)

    William E. Wilson

    1976-01-01

    Numerous attempts have been made to measure the rate of loss of SO2 in power plant plumes. If SO2 decreases more rapidly than an inert pollutant, the control measures necessary to meet SO2 standards would be eased. More recently, Swedish studies of acid rain, thought to be due to long range transport...

  16. Neutralization of arsenic pollutants, contained in natural waters: The theoretical analysis of solubility of some arsenates and optimization of the processes

    Directory of Open Access Journals (Sweden)

    Marta Litynska

    2017-01-01

    Full Text Available Arsenic belongs to chemical elements, which are often found in natural waters and make it unsuitable for consumption without special treatment. Neutralization of arsenic pollutants of natural waters by converting them into insoluble form is one of the perspective methods of dearsenication. Precipitation (by iron or aluminium coagulants, lime and adsorption (by oxides and hydroxides of iron, aluminium or manganese are among the most popular dearsenication methods. The use of these chemicals entails the formation of poorly soluble arsenates. Since the possibility of the release of arsenic compounds into the water due to the dissolution of formed arsenates depends on its solubility under appropriate conditions, it is necessary to have information about the dependence of arsenates solubility on pH. According to the calculations the solubilities of arsenates of iron(III, aluminium, manganese(II and calcium are highly dependent on pH. At pH

  17. Cu-Zn isotope constraints on the provenance of air pollution in Central Europe: Using soluble and insoluble particles in snow and rime.

    Science.gov (United States)

    Novak, Martin; Sipkova, Adela; Chrastny, Vladislav; Stepanova, Marketa; Voldrichova, Petra; Veselovsky, Frantisek; Prechova, Eva; Blaha, Vladimir; Curik, Jan; Farkas, Juraj; Erbanova, Lucie; Bohdalkova, Leona; Pasava, Jan; Mikova, Jitka; Komarek, Arnost; Krachler, Michael

    2016-11-01

    Copper (Cu) and zinc (Zn) isotope ratios can be used to fingerprint sources and dispersion pathways of pollutants in the environment. Little is known, however, about the potential of δ 65 Cu and δ 66 Zn values in liquid and solid forms of atmospheric deposition to distinguish between geogenic, industrial, local and remote sources of these potentially toxic base metals. Here we present Cu-Zn deposition fluxes at 10 mountain-top sites in the Czech Republic, a region affected by extremely high industrial emission rates 25 years ago. Additionally, we monitored isotope composition of Cu and Zn in vertical and horizontal atmospheric deposition at two sites. We compared δ 65 Cu and δ 66 Zn values in snow and rime, extracted by diluted HNO 3 and concentrated HF. Cu and Zn isotope signatures of industrial pollution sources were also determined. Cu and Zn deposition fluxes at all study sites were minute. The mean δ 65 Cu value of atmospheric deposition (-0.07‰) was higher than the mean δ 65 Cu value of pollution sources (-1.17‰). The variability in δ 65 Cu values of atmospheric deposition was lower, compared to the pollution sources. The mean δ 66 Zn value of atmospheric deposition (-0.09‰) was slightly higher than the mean δ 66 Zn value of pollution sources (-0.23‰). The variability in δ 66 Zn values of atmospheric deposition was indistinguishable from that of pollution sources. The largest isotope differences (0.35‰) were observed between the insoluble and soluble fractions of atmospheric deposition. These differences may result from different sources of Cu/Zn for each fraction. The difference in isotope composition of soluble and insoluble particles appears to be a promising tool for pollution provenance studies in Central Europe. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Natural attenuation: A feasible approach to remediation of ground water pollution at landfills?

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, T.H.; Bjerg, P.L.; Kjeldsen, P.

    2000-12-31

    Remediation of ground water pollution at old landfills with no engineered leachate collection system is a demanding and costly operation. It requires control of the landfill body, since the majority of the pollutants are still present in the landfilled waste for decades after the site has been closed. However, natural attenuation of the plume without removing the source is an attractive approach to managing leachate plumes. Natural attenuation has been implemented for petroleum hydrocarbon plumes and for chlorinated solvent plumes, primarily in the US. Natural attenuation has not yet gained a foothold with respect to leachate plumes, however. Based on the experiences gained from 10 years of research on two Danish landfills, it is suggested that natural attenuation is a feasible approach but is more complicated and demanding than in the case of petroleum hydrocarbons and chlorinated solvent.

  19. Atmospheric pollutant outflow from southern Asia: a review

    Directory of Open Access Journals (Sweden)

    M. G. Lawrence

    2010-11-01

    Full Text Available Southern Asia, extending from Pakistan and Afghanistan to Indonesia and Papua New Guinea, is one of the most heavily populated regions of the world. Biofuel and biomass burning play a disproportionately large role in the emissions of most key pollutant gases and aerosols there, in contrast to much of the rest of the Northern Hemisphere, where fossil fuel burning and industrial processes tend to dominate. This results in polluted air masses which are enriched in carbon-containing aerosols, carbon monoxide, and hydrocarbons. The outflow and long-distance transport of these polluted air masses is characterized by three distinct seasonal circulation patterns: the winter monsoon, the summer monsoon, and the monsoon transition periods. During winter, the near-surface flow is mostly northeasterly, and the regional pollution forms a thick haze layer in the lower troposphere which spreads out over millions of square km between southern Asia and the Intertropical Convergence Zone (ITCZ, located several degrees south of the equator over the Indian Ocean during this period. During summer, the heavy monsoon rains effectively remove soluble gases and aerosols. Less soluble species, on the other hand, are lifted to the upper troposphere in deep convective clouds, and are then transported away from the region by strong upper tropospheric winds, particularly towards northern Africa and the Mediterranean in the tropical easterly jet. Part of the pollution can reach the tropical tropopause layer, the gateway to the stratosphere. During the monsoon transition periods, the flow across the Indian Ocean is primarily zonal, and strong pollution plumes originating from both southeastern Asia and from Africa spread across the central Indian Ocean. This paper provides a review of the current state of knowledge based on the many observational and modeling studies over the last decades that have examined the southern Asian atmospheric pollutant outflow and its large scale

  20. Do buoyant plumes enhance cross-shelf transport in the Black Sea?

    Science.gov (United States)

    Sedakov, Roman; Zavialov, Peter; Izhitsky, Alexander

    2017-04-01

    Like many inland seas, the Black Sea is exposed to massive continental discharges on the one hand and significant anthropogenic stresses, including pollution, on the other. It is, therefore, important to understand mechanisms of advection of continental water into the sea and factors that may influence transport of such water across shelf areas. In this study, we focus on the coastal segment of the Black Sea between the Feodosia Bay, which includes nature reserve and resort areas, and the Kerch Strait. The Sea of Azov outflow penetrates into the Black Sea through the latter, forming a plume of relatively fresh, light waters with elevated concentrations of suspended matter but also pollutants, especially hydrocarbons. This plume, which can be detected via satellite imagery of the region, extends on over 70 km from the Kerch Strait outfall along Crimea shore and reaches the Feodosia Bay, making that area the most polluted of the Crimea shoreline. In situ velocity measurements were conducted at a mooring station deployed in the area at the depth of 5 and 21.5 meters during the period 17th-23rd of May 2015. These data demonstrated high correlation of the wind stress with the cross-shore component of the velocity in the surface layer and anti-correlation with that in the bottom layer during the periods when a two-layered stratification of the water column due to the occurrence of the Azov plume was present, and lack of such correlation otherwise. In order to investigate whether the buoyant plume in the surface layer is capable of fortifying the wind-driven cross-shelf exchanges, we develop a dynamical model of current forming under the influence of wind tension, pressure gradient and Earth's rotation in a simple one- and a two- layer setups. Firstly, a 2D model was investigated that did not account Coriolis effect. Secondly, a 3D model with Coriolis effect was investigated. The main parameter of the problem is the eddy diffusivity coefficient, which we choose to be

  1. Essentials of multiangle data-processing methodology for smoke polluted atmospheres

    Science.gov (United States)

    Vladimir Kovalev; A. Petkov; Cyle Wold; Shawn Urbanski; WeiMin Hao

    2011-01-01

    Essentials for investigating smoke plume characteristics with scanning lidar are discussed. Particularly, we outline basic principles for determining dynamics, heights, and optical properties of smoke plumes and layers in wildfire-polluted atmospheres. Both simulated and experimental data obtained in vicinities of wildfires with a two-wavelength scanning lidar are...

  2. Electrochemical sensors applied to pollution monitoring: Measurement error and gas ratio bias - A volcano plume case study

    Science.gov (United States)

    Roberts, T. J.; Saffell, J. R.; Oppenheimer, C.; Lurton, T.

    2014-06-01

    There is an increasing scientific interest in the use of miniature electrochemical sensors to detect and quantify atmospheric trace gases. This has led to the development of ‘Multi-Gas' systems applied to measurements of both volcanic gas emissions, and urban air pollution. However, such measurements are subject to uncertainties introduced by sensor response time, a critical issue that has received limited attention to date. Here, a detailed analysis of output from an electrochemical SO2 sensor and two H2S sensors (contrasting in their time responses and cross-sensitivities) demonstrates how instrument errors arise under the conditions of rapidly fluctuating (by dilution) gas abundances, leading to scatter and importantly bias in the reported gas ratios. In a case study at Miyakejima volcano (Japan), electrochemical sensors were deployed at both the crater-rim and downwind locations, thereby exposed to rapidly fluctuating and smoothly varying plume gas concentrations, respectively. Discrepancies in the H2S/SO2 gas mixing ratios derived from these measurements are attributed to the sensors' differing time responses to SO2 and H2S under fluctuating plume conditions, with errors magnified by the need to correct for SO2 interference in the H2S readings. Development of a sensor response model that reproduces sensor t90 behaviour (the time required to reach 90% of the final signal following a step change in gas abundance) during calibration enabled this measurement error to be simulated numerically. The sensor response times were characterised as SO2 sensor (t90 ~ 13 s), H2S sensor without interference (t90 ~ 11 s), and H2S sensor with interference (t90 ~ 20 s to H2S and ~ 32 s to SO2). We show that a method involving data integration between periods of episodic plume exposure identifiable in the sensor output yields a less biased H2S/SO2 ratio estimate than that derived from standard analysis approaches. For the Miyakejima crater-rim dataset this method yields highly

  3. Dilution in Transition Zone between Rising Plumes and Surface Plumes

    DEFF Research Database (Denmark)

    Larsen, Torben

    2004-01-01

    The papers presents some physical experiments with the dilution of sea outfall plumes with emphasize on the transition zone where the relative fast flowing vertical plume turns to a horizontal surface plume following the slow sea surface currents. The experiments show that a considerable dilution...

  4. Phase separation and soluble pollutant removal by means of alternationg current electrocoagulation

    International Nuclear Information System (INIS)

    Farrell, C.W.; Gardner-Clayson, T.W.

    1992-01-01

    Electro-Pure Systems (EPS) has undertaken a two-year laboratory program to investigate the technical and economic viability of alternation current electrocoagulation technology (ACE Technology) for Superfund site remediation. Alternating current electrocoagulation was originally developed as a treatment technology in the early 1980s to break stable aqueous suspensions of clays and coal fines in the mining industry. The technology offers a replacement for primary chemical coagulant addition to simplify effluent treatment, realize cost savings, and facilitate recovery of fine grained products that would otherwise have been lost. The traditional approach for treatment of such effluents entails addition of organic polymers or inorganic salts to promote flocculation of fine particulates and colloidi-sized oil droplets in aqueous suspensions. These flocculated materials are than separated by sedimentation or filtration. Unfortunately, chemical coagulant addition generates voluminous, gelatinous sludges which are difficult to dewater and slow to filter. As an alternative to chemical conditioning, alternation current electrocoagulation introduces into an aqueous medium highly, charged polymetric aluminum hydroxide species which will neutralize the electrostatic charges on suspended solids and oil droplets to facilitate their agglomeration (or coagulation). These species will also coprecipitate many soluble ions. ACE Technology prompts coagulation without adding any soluble species and produces a sludge with a lower contained water content and which will filter more rapidly through separation of the hazardous components from an aqueous waste the volume of potentially toxic pollutants requiring special handling and disposal can be minimized. Waste reduction goals may be accomplished by integrating this technology into a variety of operations which generate contaminated water

  5. Cross-hemispheric transport of central African biomass burning pollutants: implications for downwind ozone production

    Directory of Open Access Journals (Sweden)

    E. Real

    2010-03-01

    Full Text Available Pollutant plumes with enhanced concentrations of trace gases and aerosols were observed over the southern coast of West Africa during August 2006 as part of the AMMA wet season field campaign. Plumes were observed both in the mid and upper troposphere. In this study we examined the origin of these pollutant plumes, and their potential to photochemically produce ozone (O3 downwind over the Atlantic Ocean. Their possible contribution to the Atlantic O3 maximum is also discussed. Runs using the BOLAM mesoscale model including biomass burning carbon monoxide (CO tracers were used to confirm an origin from central African biomass burning fires. The plumes measured in the mid troposphere (MT had significantly higher pollutant concentrations over West Africa compared to the upper tropospheric (UT plume. The mesoscale model reproduces these differences and the two different pathways for the plumes at different altitudes: transport to the north-east of the fire region, moist convective uplift and transport to West Africa for the upper tropospheric plume versus north-west transport over the Gulf of Guinea for the mid-tropospheric plume. Lower concentrations in the upper troposphere are mainly due to enhanced mixing during upward transport. Model simulations suggest that MT and UT plumes are 16 and 14 days old respectively when measured over West Africa. The ratio of tracer concentrations at 600 hPa and 250 hPa was estimated for 14–15 August in the region of the observed plumes and compares well with the same ratio derived from observed carbon dioxide (CO2 enhancements in both plumes. It is estimated that, for the period 1–15 August, the ratio of Biomass Burning (BB tracer concentration transported in the UT to the ones transported in the MT is 0.6 over West Africa and the equatorial South Atlantic.

    Runs using a photochemical trajectory model, CiTTyCAT, initialized with the observations, were used to estimate

  6. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media

    International Nuclear Information System (INIS)

    Ullmann, Amos; Brauner, Neima; Vazana, Shlomi; Katz, Zhanna; Goikhman, Roman; Seemann, Boaz; Marom, Hanit; Gozin, Michael

    2013-01-01

    Highlights: • New soil remediation process using phase transition of partially miscible solvents. • Design and synthesis of new bio-degradable, organic soluble chelating agents. • Feasibility tests of the process on authentically polluted sediments and sludge. • Simultaneous removal of toxic metals and organic pollutants was demonstrated. -- Abstract: Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain (“tail”) to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N′-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied

  7. New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media

    Energy Technology Data Exchange (ETDEWEB)

    Ullmann, Amos, E-mail: Ullmann@eng.tau.ac.il [Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Brauner, Neima; Vazana, Shlomi; Katz, Zhanna [Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Goikhman, Roman [The Hebrew University of Jerusalem, The Robert H. Smith, Faculty of Agriculture, Food and Environment, Rehovot (Israel); Seemann, Boaz; Marom, Hanit [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Gozin, Michael, E-mail: cogozin@gmail.com [School of Chemistry, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2013-09-15

    Highlights: • New soil remediation process using phase transition of partially miscible solvents. • Design and synthesis of new bio-degradable, organic soluble chelating agents. • Feasibility tests of the process on authentically polluted sediments and sludge. • Simultaneous removal of toxic metals and organic pollutants was demonstrated. -- Abstract: Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain (“tail”) to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N′-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied.

  8. Development of procedures for the identification of human papilloma virus DNA fragments in laser plume

    Science.gov (United States)

    Woellmer, Wolfgang; Meder, Tom; Jappe, Uta; Gross, Gerd; Riethdorf, Sabine; Riethdorf, Lutz; Kuhler-Obbarius, Christina; Loening, Thomas

    1996-01-01

    For the investigation of laser plume for the existence of HPV DNA fragments, which possibly occur during laser treatment of virus infected tissue, human papillomas and condylomas were treated in vitro with the CO2-laser. For the sampling of the laser plume a new method for the trapping of the material was developed by use of water-soluble gelatine filters. These samples were analyzed with the polymerase chain reaction (PCR) technique, which was optimized in regard of the gelatine filters and the specific primers. Positive PCR results for HPV DNA fragments up to the size of a complete oncogene were obtained and are discussed regarding infectiousity.

  9. mathematical modelling of atmospheric dispersion of pollutants

    International Nuclear Information System (INIS)

    Mohamed, M.E.

    2002-01-01

    the main objectives of this thesis are dealing with environmental problems adopting mathematical techniques. in this respect, atmospheric dispersion processes have been investigated by improving the analytical models to realize the realistic physical phenomena. to achieve these aims, the skeleton of this work contained both mathematical and environmental topics,performed in six chapters. in chapter one we presented a comprehensive review study of most important informations related to our work such as thermal stability , plume rise, inversion, advection , dispersion of pollutants, gaussian plume models dealing with both radioactive and industrial contaminants. chapter two deals with estimating the decay distance as well as the decay time of either industrial or radioactive airborne pollutant. further, highly turbulent atmosphere has been investigated as a special case in the three main thermal stability classes namely, neutral, stable, and unstable atmosphere. chapter three is concerned with obtaining maximum ground level concentration of air pollutant. the variable effective height of pollutants has been considered throughout the mathematical treatment. as a special case the constancy of effective height has been derived mathematically and the maximum ground level concentration as well as its location have been established

  10. Considering a point-source in a regional air pollution model; Prise en compte d`une source ponctuelle dans un modele regional de pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lipphardt, M.

    1997-06-19

    This thesis deals with the development and validation of a point-source plume model, with the aim to refine the representation of intensive point-source emissions in regional-scale air quality models. The plume is modelled at four levels of increasing complexity, from a modified Gaussian plume model to the Freiberg and Lusis ring model. Plume elevation is determined by Netterville`s plume rise model, using turbulence and atmospheric stability parameters. A model for the effect of a fine-scale turbulence on the mean concentrations in the plume is developed and integrated in the ring model. A comparison between results with and without considering micro-mixing shows the importance of this effect in a chemically reactive plume. The plume model is integrated into the Eulerian transport/chemistry model AIRQUAL, using an interface between Airqual and the sub-model, and interactions between the two scales are described. A simulation of an air pollution episode over Paris is carried out, showing that the utilization of such a sub-scale model improves the accuracy of the air quality model

  11. Where the oil from surface and subsurface plumes deposited during/after Deepwater Horizon oil spill?

    Science.gov (United States)

    Yan, B.

    2016-02-01

    The Deepwater Horizon (DwH) oil spill released an estimated 4.9 million barrels (about 200 million gallons) of crude oil into the Gulf of Mexico between April 20, 2010 and July 15, 2010. Though Valentine et al. has linked the elevated oil components in some sediments with the subsurface plume, the sites with fallout from the ocean surface plume has not been identified. This piece of information is critical not only for a comprehensive scientific understanding of the ecosystem response and fate of spill-related pollutants, but also for litigation purposes and future spill response and restoration planning. In this study we focus on testing the hypothesis that marine snow from the surface plume were deposited on the sea floor over a broad area. To do so, we use publicly available data generated as part of the ongoing Natural Resource Damage Assessment (NRDA) process to assess the spatial distribution of petroleum hydrocarbons in the water column and deep-ocean sediments of the Gulf of Mexico. Sensitive hydrocarbon markers are used to differentiate hydrocarbons from surface plume, deep subsurface plume, and in-situ burning. Preliminary results suggest the overlapping but different falling sites of these plumes and the sedimentation process was controlled by various biological, chemical, and physical factors.

  12. Multi-pollutant interactions in hyporheic zones

    Science.gov (United States)

    Krause, S.; Weatherill, J.; Bonet, B.; Blaen, P.; Khamis, K.; Cassidy, N. J.; Hannah, D. M.; Rivett, M. O.; Lynch, I.; Ullah, S.

    2017-12-01

    Hyporheic zones represent hotspots of biogeochemical reactivity, with the potential to attenuate pollutants and ameliorate their impact on ecosystem functioning. Sources and types of pollutants in streambed environments are manifold, with legacy industry contaminants, agricultural pollution and emerging pollutants such as pharmaceuticals or engineered nanoparticles entering hyporheic zones along different flow paths where they mix and potentially react with each other. Current conceptualizations of drivers and controls of biogeochemical turnover in hyporheic zones highlight primarily the role of transport and reaction times but do not account for potential interactions between different pollutants. This study presents two case studies of multi-pollutant interactions to illustrate the need to consider interferences between different pollutants, their transport and reaction pathways for adequate impact assessment. We discuss in the first instance how the natural attenuation of a Trichloroethylene (TCE) groundwater plume in an agricultural catchment is limited by high riparian and hyporheic nitrate concentrations. As nitrate outcompeted TCE in its reaction with organic carbon as electron donor, TCE attenuation was in this case limited to hyporheic denitrification hotspots. Hence any pollution control measures to reduce the impact of this TCE plume require a reduction of agricultural nitrate loads, highlighting the connectedness of legacy (TCE) and more recent (nitrate) pollution problems. In the second case, we investigate how the labile organic carbon content of streambed sediments as main control of hyporheic respiration is overridden by exposure to different silver nanoparticle concentrations, representing emerging pollutants in many of our rivers. Also in this case, the impacts of different stressors (nanoparticle exposure) and drivers (availability of organic matter, water temperature) are interacting in their impacts on hyporheic zone functioning. We argue that

  13. The dispersion characteristics of air pollution from the world's megacities

    Directory of Open Access Journals (Sweden)

    M. Cassiani

    2013-10-01

    Full Text Available Megacities are extreme examples of the continuously growing urbanization of the human population that pose (new challenges to the environment and human health at a local scale. However, because of their size megacities also have larger-scale effects, and more research is needed to quantify their regional- and global-scale impacts. We performed a study of the characteristics of pollution plumes dispersing from a group of 36 of the world's megacities using the Lagrangian particle model FLEXPART and focusing on black carbon (BC emissions during the years 2003–2005. BC was selected since it is representative of combustion-related emissions and has a significant role as a short-lived climate forcer. Based on the BC emissions two artificial tracers were modeled: a purely passive tracer and one subject to wet and dry deposition more closely resembling the behavior of a true aerosol. These tracers allowed us to investigate the role of deposition processes in determining the impact of megacities' pollutant plumes. The particles composing the plumes have been sampled in space and time. The time sampling allowed us to investigate the evolution of the plume from its release up to 48 days after emission and to generalize our results for any substance decaying with a timescale sufficiently shorter than the time window of 48 days. The physical characteristics of the time-averaged plume have been investigated, and this showed that, although local conditions are important, overall a city's latitude is the main factor influencing both the local and the regional-to-global dispersion of its pollution. We also repeated the calculations of some of the regional-pollution-potential metrics previously proposed by Lawrence et al. (2007, thus extending their results to a depositing scalar and retaining the evolution in time for all the plumes. Our results agreed well with their previous results despite being obtained using a totally different modeling framework. For the

  14. A regional scale model for ozone in the United States with subgrid representation of urban and power plant plumes

    International Nuclear Information System (INIS)

    Sillman, S.; Logan, J.A.; Wofsy, S.C.

    1990-01-01

    A new approach to modeling regional air chemistry is presented for application to industrialized regions such as the continental US. Rural chemistry and transport are simulated using a coarse grid, while chemistry and transport in urban and power plant plumes are represented by detailed subgrid models. Emissions from urban and power plant sources are processed in generalized plumes where chemistry and dilution proceed for 8-12 hours before mixing with air in a large resolution element. A realistic fraction of pollutants reacts under high-NO x conditions, and NO x is removed significantly before dispersal. Results from this model are compared with results from grid odels that do not distinguish plumes and with observational data defining regional ozone distributions. Grid models with coarse resolution are found to artificially disperse NO x over rural areas, therefore overestimating rural levels of both NO x and O 3 . Regional net ozone production is too high in coarse grid models, because production of O 3 is more efficient per molecule of NO x in the low-concentration regime of rural areas than in heavily polluted plumes from major emission sources. Ozone levels simulated by this model are shown to agree with observations in urban plumes and in rural regions. The model reproduces accurately average regional and peak ozone concentrations observed during a 4-day ozone episode. Computational costs for the model are reduced 25-to 100-fold as compared to fine-mesh models

  15. Solar Coronal Plumes

    Directory of Open Access Journals (Sweden)

    Giannina Poletto

    2015-12-01

    Full Text Available Polar plumes are thin long ray-like structures that project beyond the limb of the Sun polar regions, maintaining their identity over distances of several solar radii. Plumes have been first observed in white-light (WL images of the Sun, but, with the advent of the space era, they have been identified also in X-ray and UV wavelengths (XUV and, possibly, even in in situ data. This review traces the history of plumes, from the time they have been first imaged, to the complex means by which nowadays we attempt to reconstruct their 3-D structure. Spectroscopic techniques allowed us also to infer the physical parameters of plumes and estimate their electron and kinetic temperatures and their densities. However, perhaps the most interesting problem we need to solve is the role they cover in the solar wind origin and acceleration: Does the solar wind emanate from plumes or from the ambient coronal hole wherein they are embedded? Do plumes have a role in solar wind acceleration and mass loading? Answers to these questions are still somewhat ambiguous and theoretical modeling does not provide definite answers either. Recent data, with an unprecedented high spatial and temporal resolution, provide new information on the fine structure of plumes, their temporal evolution and relationship with other transient phenomena that may shed further light on these elusive features.

  16. Entrainment by turbulent plumes

    Science.gov (United States)

    Parker, David; Burridge, Henry; Partridge, Jamie; Linden, Paul

    2017-11-01

    Plumes are of relevance to nature and real consequence to industry. While the Morton, Taylor & Turner (1956) plume model is able to estimate the mean physical flux parameters, the process of entrainment is only parametrised in a time-averaged sense and a deeper understanding is key to understanding how they evolve. Various flow configurations, resulting in different entrainment values, are considered; we perform simultaneous PIV and plume-edge detection on saline plumes in water resulting from a point source, a line source and a line source where a vertical wall is placed immediately adjacent. Of particular interest is the effect the large scale eddies, forming at the edge of the plume and engulfing ambient fluid, have on the entrainment process. By using velocity statistics in a coordinate system based on the instantaneous scalar edge of the plume the significance of this large scale engulfment is quantified. It is found that significant mass is transported outside the plumes, in particular in regions where large scale structures are absent creating regions of relatively high-momentum ambient fluid. This suggests that the large scale processes, whereby ambient fluid is engulfed into the plume, contribute significantly to the entrainment.

  17. The source and longevity of sulfur in an Icelandic flood basalt eruption plume

    Science.gov (United States)

    Ilyinskaya, Evgenia; Edmonds, Marie; Mather, Tamsin; Schmidt, Anja; Hartley, Margaret; Oppenheimer, Clive; Pope, Francis; Donovan, Amy; Sigmarsson, Olgeir; Maclennan, John; Shorttle, Oliver; Francis, Peter; Bergsson, Baldur; Barsotti, Sara; Thordarson, Thorvaldur; Bali, Eniko; Keller, Nicole; Stefansson, Andri

    2015-04-01

    The Holuhraun fissure eruption (Bárðarbunga volcanic system, central Iceland) has been ongoing since 31 August 2014 and is now the largest in Europe since the 1783-84 Laki event. For the first time in the modern age we have the opportunity to study at first hand the environmental impact of a flood basalt fissure eruption (>1 km3 lava). Flood basalt eruptions are one of the most hazardous volcanic scenarios in Iceland and have had enormous societal and economic consequences across the northern hemisphere in the past. The Laki eruption caused the deaths of >20% of the Icelandic population by environmental pollution and famine and potentially also increased European levels of mortality through air pollution by sulphur-bearing gas and aerosol. A flood basalt eruption was included in the UK National Risk Register in 2012 as one of the highest priority risks. The gas emissions from Holuhraun have been sustained since its beginning, repeatedly causing severe air pollution in populated areas in Iceland. During 18-22 September, SO2 fluxes reached 45 kt/day, a rate of outgassing rarely observed during sustained eruptions, suggesting that the sulfur loading per kg of erupted magma exceeds both that of other recent eruptions in Iceland and perhaps also other historic basaltic eruptions globally. This raises key questions regarding the origin of these prodigious quantities of sulphur. A lack of understanding of the source of this sulfur, the conversion rates of SO2 gas into aerosol, the residence times of aerosol in the plume and the dependence of these on meteorological factors is limiting our confidence in the ability of atmospheric models to forecast gas and aerosol concentrations in the near- and far-field from Icelandic flood basalt eruptions. In 2015 our group is undertaking a project funded by UK NERC urgency scheme to investigate several aspects of the sulfur budget at Holuhraun using a novel and powerful approach involving simultaneous tracking of sulfur and

  18. Simulation of plume rise: Study the effect of stably stratified turbulence layer on the rise of a buoyant plume from a continuous source by observing the plume centroid

    Science.gov (United States)

    Bhimireddy, Sudheer Reddy; Bhaganagar, Kiran

    2016-11-01

    Buoyant plumes are common in atmosphere when there exists a difference in temperature or density between the source and its ambience. In a stratified environment, plume rise happens until the buoyancy variation exists between the plume and ambience. In a calm no wind ambience, this plume rise is purely vertical and the entrainment happens because of the relative motion of the plume with ambience and also ambient turbulence. In this study, a plume centroid is defined as the plume mass center and is calculated from the kinematic equation which relates the rate of change of centroids position to the plume rise velocity. Parameters needed to describe the plume are considered as the plume radius, plumes vertical velocity and local buoyancy of the plume. The plume rise velocity is calculated by the mass, momentum and heat conservation equations in their differential form. Our study focuses on the entrainment velocity, as it depicts the extent of plume growth. This entrainment velocity is made up as sum of fractions of plume's relative velocity and ambient turbulence. From the results, we studied the effect of turbulence on the plume growth by observing the variation in the plume radius at different heights and the centroid height reached before loosing its buoyancy.

  19. Fire analog: a comparison between fire plumes and energy center cooling tower plumes

    Energy Technology Data Exchange (ETDEWEB)

    Orgill, M.M.

    1977-10-01

    Thermal plumes or convection columns associated with large fires are compared to thermal plumes from cooling towers and proposed energy centers to evaluate the fire analog concept. Energy release rates of mass fires are generally larger than for single or small groups of cooling towers but are comparable to proposed large energy centers. However, significant physical differences exist between cooling tower plumes and fire plumes. Cooling tower plumes are generally dominated by ambient wind, stability and turbulence conditions. Fire plumes, depending on burning rates and other factors, can transform into convective columns which may cause the fire behavior to become more violent. This transformation can cause strong inflow winds and updrafts, turbulence and concentrated vortices. Intense convective columns may interact with ambient winds to create significant downwind effects such as wakes and Karman vortex streets. These characteristics have not been observed with cooling tower plumes to date. The differences in physical characteristics between cooling tower and fire plumes makes the fire analog concept very questionable even though the approximate energy requirements appear to be satisfied in case of large energy centers. Additional research is suggested in studying the upper-level plume characteristics of small experimental fires so this information can be correlated with similar data from cooling towers. Numerical simulation of fires and proposed multiple cooling tower systems could also provide comparative data.

  20. [Pollution Characteristics and Light Extinction Effects of Water-soluble Ions in PM2.5 During Winter Hazy Days at North Suburban Nanjing].

    Science.gov (United States)

    Zhou, Yao-yao; Ma, Yan; Zheng, Jun; Cui, Fen-ping; Wang, Li

    2015-06-01

    To investigate the characteristics of water-soluble ions in PM2.5 and their contribution to light extinction in haze days, on-line monitoring of PM2.5. was conducted at North Suburban Nanjing from 25 January through 3 February, 2013. Water-soluble components were collected with a particle-into-liquid sampler (PILS), and analyzed by ion chromatography (IC) for the contents of SO4(2-), NO3-, NH4+, Cl-, Na+, K+, Mg2+ and Ca2+ Simultaneously particle size distributions were measured using scanning mobility particle sizer (SMPS) and Aerodynamic Particle Sizer (APS). The absorption and scattering coefficients were measured by three-wavelength photoacoustic soot spectrometer (PASS-3). Trace gases (SO2, NO2 etc.) were also monitored. The results showed that the average concentrations of total water-soluble ions were 70.3 and 22.9 microg x m(-3) in haze and normal days, respectively. Secondary hygroscopic components including SO4(2-), NO3- and NH4+ were the major ionic pollutants. Hazy days favored the conversion of SO2 and NOx, to SO4(2-) and NO3-, respectively, and in particular the oxidation of NOx. Using multiple linear regression statistical method, the empirical relationship between the dry aerosol extinction coefficient and the chemical composition was established. NH4NO3 was found to be the largest contributor to aerosol extinction in winter in Nanjing, followed by (NH4)2SO4, OC and EC. In two heavy pollution events, the increase of ion concentrations was influenced by the increase of primary emissions and secondary transformation.

  1. The Biogeochemistry of Contaminant Groundwater Plumes Arising from Waste Disposal Facilities

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Albrechtsen, Hans-Jørgen; Kjeldsen, Peter

    2014-01-01

    Landfills with solid waste are abundant sources of groundwater pollution all over the world. Old uncontrolled municipal landfills are often large, heterogeneous sources with demolition waste, minor fractions of commercial or industrial waste, and organic waste from households. Strongly anaerobic...... leachate with a high content of dissolved organic carbon, salts, and ammonium, as well as specific organic compounds and metals is released from the waste for decades or centuries. Landfill leachate plume hosts a variety of biogeochemical processes, which is the key to understand the significant potential...... and the literature are the following: (1) Local hydrogeological conditions in the landfill area may affect the spreading of the contaminants; (2) investigations of landfill leachate plumes in geologic settings with clayey till deposits and fractured consolidated sediments are lacking; (3) the size of the landfill...

  2. Observation and modeling of the evolution of Texas power plant plumes

    Directory of Open Access Journals (Sweden)

    W. Zhou

    2012-01-01

    Full Text Available During the second Texas Air Quality Study 2006 (TexAQS II, a full range of pollutants was measured by aircraft in eastern Texas during successive transects of power plant plumes (PPPs. A regional photochemical model is applied to simulate the physical and chemical evolution of the plumes. The observations reveal that SO2 and NOy were rapidly removed from PPPs on a cloudy day but not on the cloud-free days, indicating efficient aqueous processing of these compounds in clouds. The model reasonably represents observed NOx oxidation and PAN formation in the plumes, but fails to capture the rapid loss of SO2 (0.37 h−1 and NOy (0.24 h−1 in some plumes on the cloudy day. Adjustments to the cloud liquid water content (QC and the default metal concentrations in the cloud module could explain some of the SO2 loss. However, NOy in the model was insensitive to QC. These findings highlight cloud processing as a major challenge to atmospheric models. Model-based estimates of ozone production efficiency (OPE in PPPs are 20–50 % lower than observation-based estimates for the cloudy day.

  3. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.H., E-mail: hlh@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huo, R.; Yang, D. [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  4. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow.

    Science.gov (United States)

    Hu, L H; Huo, R; Yang, D

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons--a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  5. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    International Nuclear Information System (INIS)

    Hu, L.H.; Huo, R.; Yang, D.

    2009-01-01

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  6. NW Iberia Shelf Dynamics. Study of the Douro River Plume.

    Directory of Open Access Journals (Sweden)

    Isabel Iglesias

    2014-06-01

    Full Text Available River plumes are one of the most important mechanisms that transport the terrestrial materials to the coast and the ocean. Some examples of those materials are pollutants, essential nutrients, which enhance the phytoplankton productivity or sediments, which settle on the seabed producing modifications on the bathymetry affecting the navigation channels. The mixing between the riverine and the oceanic waters can induce instabilities, which might generate bulges, filaments, and buoyant currents over the continental shelf. Offshore, the buoyant riverine water could form a front with the oceanic waters often related with the occurrence of current-jets, eddies and strong mixing. The study and modelling of the river plumes is a key factor for the complete understanding of sediment transport mechanisms and patterns, and of coastal physics and dynamic processes. On this study the Douro River plume will be simulated. The Douro River is located on the north-west Iberian coast and its daily averaged freshwater discharge can range values from 0 to 13000 m3/s. This variability impacts the formation of the river plumes and its dispersion along the continental shelf. This study builds on the long-term objective of generate a Douro River plume forecasting system as part of the RAIA and RAIA.co projects. Satellite imagery was analyzed showing that the river Douro is one of the main sources of suspended particles, dissolved material and chlorophyll in the NW Iberian Shelf. The Regional Oceanic Modeling System (ROMS model was selected to reproduce scenarios of plume generation, retention and dispersion. Whit this model, three types of simulations were performed: (i schematic winds simulations with prescribed river flow, wind speed and direction; (ii multi-year climatological simulation, with river flow and temperature change for each month; (iii extreme case simulation, based on the Entre-os-Rios accident situation. The schematic wind case-studies suggest that the

  7. Seismic Imaging of Mantle Plumes

    Science.gov (United States)

    Nataf, Henri-Claude

    The mantle plume hypothesis was proposed thirty years ago by Jason Morgan to explain hotspot volcanoes such as Hawaii. A thermal diapir (or plume) rises from the thermal boundary layer at the base of the mantle and produces a chain of volcanoes as a plate moves on top of it. The idea is very attractive, but direct evidence for actual plumes is weak, and many questions remain unanswered. With the great improvement of seismic imagery in the past ten years, new prospects have arisen. Mantle plumes are expected to be rather narrow, and their detection by seismic techniques requires specific developments as well as dedicated field experiments. Regional travel-time tomography has provided good evidence for plumes in the upper mantle beneath a few hotspots (Yellowstone, Massif Central, Iceland). Beneath Hawaii and Iceland, the plume can be detected in the transition zone because it deflects the seismic discontinuities at 410 and 660 km depths. In the lower mantle, plumes are very difficult to detect, so specific methods have been worked out for this purpose. There are hints of a plume beneath the weak Bowie hotspot, as well as intriguing observations for Hawaii. Beneath Iceland, high-resolution tomography has just revealed a wide and meandering plume-like structure extending from the core-mantle boundary up to the surface. Among the many phenomena that seem to take place in the lowermost mantle (or D''), there are also signs there of the presence of plumes. In this article I review the main results obtained so far from these studies and discuss their implications for plume dynamics. Seismic imaging of mantle plumes is still in its infancy but should soon become a turbulent teenager.

  8. A Polymer "Pollution Solution" Classroom Activity.

    Science.gov (United States)

    Helser, Terry L.

    1996-01-01

    Explains an approach to presenting polymer chemistry to nonmajors that employs polystyrene foam, foam peanuts made from water soluble starch, and water soluble plastic bags. Students are presented with a pollution scenario and are guided to the discovery of solutions. (DDR)

  9. Gas-phase chemical characteristics of Asian emission plumes observed during ITCT 2K2 over the eastern North Pacific Ocean

    Science.gov (United States)

    Nowak, J. B.; Parrish, D. D.; Neuman, J. A.; Holloway, J. S.; Cooper, O. R.; Ryerson, T. B.; Nicks, D. K.; Flocke, F.; Roberts, J. M.; Atlas, E.; de Gouw, J. A.; Donnelly, S.; Dunlea, E.; Hübler, G.; Huey, L. G.; Schauffler, S.; Tanner, D. J.; Warneke, C.; Fehsenfeld, F. C.

    2004-12-01

    The gas-phase chemical characteristics of emission plumes transported from Asia across the Pacific Ocean observed during the Intercontinental Transport and Chemical Transformation experiment in 2002 (ITCT 2K2) are described. Plumes measured in the troposphere from an aircraft were separated from the background air in data analysis using 1-s measurements of carbon monoxide (CO), total reactive nitrogen (NOy), and other gas-phase species along with back trajectory analysis. On the basis of these measurements, Asian transport plumes with CO mixing ratios greater than 150 ppbv were observed on seven flights. Correlations between 1-s observations of CO, ozone (O3), and NOy are used to characterize the plumes. The NOy/CO ratios were similar in each plume and significantly lower than those derived from estimated Asian emission ratios, indicating substantial removal of soluble NOy species during transport. Observations of nitric oxide (NO), nitrogen dioxide (NO2), nitric acid (HNO3), peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and alkyl nitrates are used with the NOy measurements to further distinguish the transport plumes by their NOy partitioning. NOy was primarily in the form of PAN in plumes that were transported in cold high-latitude and high-altitude regions, whereas in plumes transported in warmer, lower latitude and altitude regions, NOy was mainly HNO3. Additional gas-phase species enhanced in these plumes include sulfuric acid, methanol, acetone, propane, and ethane. The O3/CO ratio varied among the plumes and was affected by the mixing of anthropogenic and stratospheric influences. The complexity of this mixing prevents the determination of the relative contribution of anthropogenic and stratospheric influences to the observed O3 levels.

  10. Pacific Northwest Laboratory Gulfstream I measurements of the Kuwait oil-fire plume, July--August 1991

    Energy Technology Data Exchange (ETDEWEB)

    Busness, K.M.; Hales, J.M.; Hannigan, R.V.; Thorp, J.M.; Tomich, S.D.; Warren, M.J. (Pacific Northwest Lab., Richland, WA (United States)); Al-Sunaid, A.A. (Saudi ARAMCO, Dhahran (Saudi Arabia)); Daum, P.H.; Mazurek, M. (Brookhaven National Lab., Upton, NY (United States))

    1992-11-01

    In 1991, the Pacific Northwest Laboratory conducted a series of aircraft measurements to determine pollutant and radiative properties of the smoke plume from oil fires in Kuwait. This work was sponsored by the US Department emanating of Energy, in cooperation with several other agencies as part of an extensive effort coordinated by the World Meteorological Organization, to obtain a comprehensive data set to assess the characteristics of the plume and its environmental impact. This report describes field measurement activities and introduces the various data collected, but provides only limited analyses of these data. Results of further data analyses will be presented in subsequent open-literature publications.

  11. Linking phytoremediated pollutant removal to biomass economic opportunities

    International Nuclear Information System (INIS)

    Licht, Louis A.; Isebrands, J.G.

    2005-01-01

    Phytoremediation (phyto) strategies employ trees, shrubs, and/or grasses for treating contaminated air, soil, or water. These strategies include buffers, vegetation filters, in situ phytoremediation plantings, and percolation controlling vegetative caps. The design parameter that separates phytoremediation from landscaping is purposefully placing and growing a root-zone reactor volume with predictable pollutant removal performance. This phyto reactor integrates with other engineered systems to cover landfills, treat petrochemical spills in soils, intercept a soluble subsurface plume, and capture non-point surface sediment entrained in urban or field runoff. There are many potential economic opportunities for biomass associated with phytoremediation, including bioenergy and traditional industrial products such as solid wood products and reconstituted products (i.e., paper, chip board, laminated beams, extruded trim). More intangibly, phyto creates environmental benefits such as soil erosion control, carbon sequestration, and wildlife habitat. Phyto also creates socio-economic benefits by diversify regional manufacturing into new products that employs local labor, thus building value-added industry. Alternative crops develop a greater diversity of products from the farmland, making the regional economy less exposed to global commodity crop price fluctuations. Thus, a strategic phyto treatment of non-point agricultural runoff would help diversify land use from annually tilled crops (corn, soybeans, wheat) into perennial, untilled tree crops. A landscape rebuilt using phyto would create diversity represented in business potential, healthier air and water, wildlife habitat, and aesthetics. Moreover, phyto provides local and current pollutant treatment. Such timely treatment of pollutants that would otherwise move to our downstream or downwind neighbors is key to the environmental justice concept. We present four case study summaries to illustrate installed commercial

  12. Linking phytoremediated pollutant removal to biomass economic opportunities

    International Nuclear Information System (INIS)

    Licht, Louis A.; Isebrands, J.G.

    2005-01-01

    Phytoremediation (phyto) strategies employ trees, shrubs, and/or grasses for treating contaminated air, soil, or water. These strategies include buffers, vegetation filters, in situ phytoremediation plantings, and percolation controlling vegetative caps. The design parameter that separates phytoremediation from landscaping is purposefully placing and growing a root-zone reactor volume with predictable pollutant removal performance. This phyto reactor integrates with other engineered systems to cover landfills, treat petrochemical spills in soils, intercept a soluble subsurface plume, and capture non-point surface sediment entrained in urban or field runoff. There are many potential economic opportunities for biomass associated with phytoremediation, including bioenergy and traditional industrial products such as solid wood products and reconstituted products (i.e., paper, chip board, laminated beams, extruded trim). More intangibly, phyto creates environmental benefits such as soil erosion control, carbon sequestration, and wildlife habitat. Phyto also creates socio-economic benefits by diversify regional manufacturing into new products that employs local labor, thus building value-added industry. Alternative crops develop a greater diversity of products from the farmland, making the regional economy less exposed to global commodity crop price fluctuations. Thus, a strategic phyto treatment of non-point agricultural runoff would help diversify land use from annually tilled crops (corn, soybeans, wheat) into perennial, untilled tree crops. A landscape rebuilt using phyto would create diversity represented in business potential, healthier air and water, wildlife habitat, and aesthetics. Moreover, phyto provides local and current pollutant treatment. Such timely treatment of pollutants that would otherwise move to our downstream or downwind neighbors is key to the environmental justice concept. We present four case study summaries to illustrate installed commercial

  13. A buoyant plume adjacent to a headland-Observations of the Elwha River plume

    Science.gov (United States)

    Warrick, J.A.; Stevens, A.W.

    2011-01-01

    Small rivers commonly discharge into coastal settings with topographic complexities - such as headlands and islands - but these settings are underrepresented in river plume studies compared to more simplified, straight coasts. The Elwha River provides a unique opportunity to study the effects of coastal topography on a buoyant plume, because it discharges into the Strait of Juan de Fuca on the western side of its deltaic headland. Here we show that this headland induces flow separation and transient eddies in the tidally dominated currents (O(100. cm/s)), consistent with other headlands in oscillatory flow. These flow conditions are observed to strongly influence the buoyant river plume, as predicted by the "small-scale" or "narrow" dynamical classification using Garvine's (1995) system. Because of the transient eddies and the location of the river mouth on the headland, flow immediately offshore of the river mouth is directed eastward twice as frequently as it is westward. This results in a buoyant plume that is much more frequently "bent over" toward the east than the west. During bent over plume conditions, the plume was attached to the eastern shoreline while having a distinct, cuspate front along its westernmost boundary. The location of the front was found to be related to the magnitude and direction of local flow during the preceding O(1. h), and increases in alongshore flow resulted in deeper freshwater mixing, stronger baroclinic anomalies, and stronger hugging of the coast. During bent over plume conditions, we observed significant convergence of river plume water toward the frontal boundary within 1. km of the river mouth. These results show how coastal topography can strongly influence buoyant plume behavior, and they should assist with understanding of initial coastal sediment dispersal pathways from the Elwha River during a pending dam removal project. ?? 2010.

  14. Characteristics of bubble plumes, bubble-plume bubbles and waves from wind-steepened wave breaking

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G. de

    2007-01-01

    Observations of breaking waves, associated bubble plumes and bubble-plume size distributions were used to explore the coupled evolution of wave-breaking, wave properties and bubble-plume characteristics. Experiments were made in a large, freshwater, wind-wave channel with mechanical wind-steepened

  15. Measurements at cooling tower plumes. Part 3. Three-dimensional measurements at cooling tower plumes

    International Nuclear Information System (INIS)

    Fortak, H.

    An extended field experiment is described in which cooling tower plumes were studied by means of three-dimensional in situ measurements. The goal was to obtain input data for numerical models of cooling tower plumes. Of special interest were data for testing or developing assumptions for sub-grid parametrizations. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station Neurath and also two (1975) at the single cooling tower of the RWE power station Meppen. Because of the broad spectrum of weather situations it can be assumed that the results are representative with regard to the interrelationship between structure of cooling tower plume and large-scale meteorological situation. A large number of flights with a powered glider crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapor pressure. Therefore, a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the boundary, which could be defined by the mentioned jumps of temperature and vapor pressure, a maximum of downward vertical motion could be observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. High-resolution aerology is necessary in order to explain the structure and behavior of such plumes. This is especially the case in investigations regarding the dynamic break-through of temperature inversions. Such cases were observed frequently under various meteorological conditions and are described

  16. On predicting mantle mushroom plumes

    Directory of Open Access Journals (Sweden)

    Ka-Kheng Tan

    2011-04-01

    Top cooling may produce plunging plumes of diameter of 585 km and at least 195 Myr old. The number of cold plumes is estimated to be 569, which has not been observed by seismic tomography or as cold spots. The cold plunging plumes may overwhelm and entrap some of the hot rising plumes from CMB, so that together they may settle in the transition zone.

  17. Model calculations of the chemical processes occurring in the plume of a coal-fired power plant

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, J F; Luria, M

    1982-02-01

    Computer simulations of the homogeneous, gas phase chemical reactions which occur in the plume of a coal-fired power plant were conducted in an effort to understand the influence of various environmental parameters on the production of secondary pollutants. Input data for the model were selected to reproduce the dilution of a plume from a medium-sized power plant. The environmental conditions chosen were characteristic of those found during mid-August in the south-eastern United States. Under most conditions examined, it was found that hydroxyl radicals were the most important species in the homogeneous conversion of stack gases into secondary pollutants. Other free radicals, such as HO/sub 2/ and CH/sub 3/O/sub 2/, exceeded the contribution of HO radicals only when high background hydrocarbon concentrations are used. The conversion rates calculated for the oxidation of SO/sub 2/ to SO/sub 4//sup 2 -/ in these plumes were consistent with those determined experimentally. The concentrations and relative proportions of NO/sub x/ (from the power plant) and reactive hydrocarbons (from the background air) determine, to a large extent, the plume reactivity. Free radical production is suppressed during the initial stages of dilution due to the high NO/sub x/ levels. Significant dilution is required before a suitable mix is attained which can sustain the free radical chain processes common to smog chemistry. In most cases, the free radical concentrations were found to pass through maxima and return to background levels. Under typical summertime conditions, the hyroxyl radical concentration was found to reach a maximum at a HC/NO/sub x/ ratio of approximately 20.

  18. Investigations into exhaust air plume diffusion in the atmosphere. Progress report July 1973 - June 1974. P. 1

    International Nuclear Information System (INIS)

    Vogt, K.J.; Geiss, H.; Horbert, M.; Nordsieck, H.; Polster, G.; Rohloff, F.

    1974-09-01

    The paper is the first part of the status report on the research project 'Diffusion of pollutants in the atmosphere and environmental hazards'. It investigates the diffusion of exhaust air plumes in tracer experiments, thereby continuing the present investigations of the same issue. (orig./AK) [de

  19. Modeling of atmospheric pollutant transfers

    International Nuclear Information System (INIS)

    Jourdain, F.

    2007-01-01

    Modeling is today a common tool for the evaluation of the environmental impact of atmospheric pollution events, for the design of air monitoring networks or for the calculation of pollutant concentrations in the ambient air. It is even necessary for the a priori evaluation of the consequences of a pollution plume. A large choice of atmospheric transfer codes exist but no ideal tool is available which allows to model all kinds of situations. The present day approach consists in combining different types of modeling according to the requested results and simulations. The CEA has a solid experience in this domain and has developed independent tools for the impact and safety studies relative to industrial facilities and to the management of crisis situations. (J.S.)

  20. The 2016 Case for Mantle Plumes and a Plume-Fed Asthenosphere (Augustus Love Medal Lecture)

    Science.gov (United States)

    Morgan, Jason P.

    2016-04-01

    The process of science always returns to weighing evidence and arguments for and against a given hypothesis. As hypotheses can only be falsified, never universally proved, doubt and skepticism remain essential elements of the scientific method. In the past decade, even the hypothesis that mantle plumes exist as upwelling currents in the convecting mantle has been subject to intense scrutiny; from geochemists and geochronologists concerned that idealized plume models could not fit many details of their observations, and from seismologists concerned that mantle plumes can sometimes not be 'seen' in their increasingly high-resolution tomographic images of the mantle. In the place of mantle plumes, various locally specific and largely non-predictive hypotheses have been proposed to explain the origins of non-plate boundary volcanism at Hawaii, Samoa, etc. In my opinion, this debate has now passed from what was initially an extremely useful restorative from simply 'believing' in the idealized conventional mantle plume/hotspot scenario to becoming an active impediment to our community's ability to better understand the dynamics of the solid Earth. Having no working hypothesis at all is usually worse for making progress than having an imperfect and incomplete but partially correct one. There continues to be strong arguments and strong emerging evidence for deep mantle plumes. Furthermore, deep thermal plumes should exist in a mantle that is heated at its base, and the existence of Earth's (convective) geodynamo clearly indicates that heat flows from the core to heat the mantle's base. Here I review recent seismic evidence by French, Romanowicz, and coworkers that I feel lends strong new observational support for the existence of deep mantle plumes. I also review recent evidence consistent with the idea that secular core cooling replenishes half the mantle's heat loss through its top surface, e.g. that the present-day mantle is strongly bottom heated. Causes for

  1. Quantifying the Intercontinental and Global Reach and Effects of Pollution

    Science.gov (United States)

    Chatfield, Robert B.; Guo, Zitan

    2000-01-01

    The Atmospheric Chemistry Modeling Group is participating in an international effort to explore the projected interactions of the atmosphere with biota, human activity, and the natural environment over the next three decades. The group uses computer simulations and statistical analyses to compare theory and observations of the composition of the lower atmosphere. This study of global habitability change is part of a more ambitious activity to understand global habitability. This broad planetary understanding is central to planetary habitability, biomarker detection, and similar aspects of Astrobiology. The group has made highly detailed studies of immense intercontinental plumes that affect the chemistry of the global atmosphere, especially the region below the ozone (O3) layer whose chemical composition defines the conditions for healthy humans and the biosphere. For some decades there has been concern about the pollution from cities and industrial burning and its possible effect in increasing smog ozone, not only in continental regions, but also in plumes that spread downwind. Recently, there has been new concern about another kind of pollution plume. Projections for a greatly expanded aircraft fleet imply that there will be plumes of nitrogen oxides (NO(x)) from jet exhaust in the Northern Hemisphere downwind of major air traffic routes. Both of these are tied to large-scale O3 in the troposphere, where it is toxic to humans and plant tissues.

  2. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... above a point heat source cannot be used. This is caused either by the way of generating the plume including a long intermediate region or by the environmental conditions where vertical temperature gradients are present. The flow has a larger angle of spread and the entrainment factor is greather than...... turbulent plumes from different heated bodies are investigated. The measurements have taken place in a full-scale test room where the vertical temperature gradient have been changed. The velocity and the temperature distribution in the plume are measured. Large scale plume axis wandering is taken...

  3. Life Cycle of Mantle Plumes: A perspective from the Galapagos Plume (Invited)

    Science.gov (United States)

    Gazel, E.; Herzberg, C. T.

    2009-12-01

    Hotspots are localized sources of heat and magmatism considered as modern-day evidence of mantle plumes. Some hotspots are related to massive magmatic production that generated Large Igneous Provinces (LIPS), an initial-peak phase of plume activity with a mantle source hotter and more magmatically productive than present-day hotspots. Geological mapping and geochronological studies have shown much lower eruption rates for OIB compared to lavas from Large Igneous Provinces LIPS such as oceanic plateaus and continental flood provinces. Our study is the first quantitative petrological comparison of mantle source temperatures and extent of melting for OIB and LIP sources. The wide range of primary magma compositions and inferred mantle potential temperatures for each LIP and OIB occurrence suggest that this rocks originated form a hotspot, a spatially localized source of heat and magmatism restricted in time. Extensive outcrops of basalt, picrite, and sometimes komatiite with circa 65-95 Ma ages occupy portions of the pacific shore of Central and South America included in the Caribbean Large Igneous Province (CLIP). There is general consensus of a Pacific-origin of CLIP and most studies suggest that it was produced by melting in the Galapagos mantle plume. The Galapagos connection is consistent with isotopic and geochemical similarities with lavas from the present-day Galapagos hotspot. A Galapagos link for rocks in South American oceanic complexes (eg. the island of Gorgona) is more controversial and requires future work. The MgO and FeO contents of lavas from the Galapagos related lavas and their primary magmas have decreased since the Cretaceous. From petrological modeling we infer that these changes reflect a cooling of the Galapagos mantle plume from a potential temperature of 1560-1620 C in the Cretaceous to 1500 C at the present time. These temperatures are higher than 1350 C for ambient mantle associated with oceanic ridges, and provide support for the mantle

  4. Scaling for turbulent viscosity of buoyant plumes in stratified fluids: PIV measurement with implications for submarine hydrothermal plume turbulence

    Science.gov (United States)

    Zhang, Wei; He, Zhiguo; Jiang, Houshuo

    2017-11-01

    Time-resolved particle image velocimetry (PIV) has been used to measure instantaneous two-dimensional velocity vector fields of laboratory-generated turbulent buoyant plumes in linearly stratified saltwater over extended periods of time. From PIV-measured time-series flow data, characteristics of plume mean flow and turbulence have been quantified. To be specific, maximum plume penetration scaling and entrainment coefficient determined from the mean flow agree well with the theory based on the entrainment hypothesis for buoyant plumes in stratified fluids. Besides the well-known persistent entrainment along the plume stem (i.e., the 'plume-stem' entrainment), the mean plume velocity field shows persistent entrainment along the outer edge of the plume cap (i.e., the 'plume-cap' entrainment), thereby confirming predictions from previous numerical simulation studies. To our knowledge, the present PIV investigation provides the first measured flow field data in the plume cap region. As to measured plume turbulence, both the turbulent kinetic energy field and the turbulence dissipation rate field attain their maximum close to the source, while the turbulent viscosity field reaches its maximum within the plume cap region; the results also show that maximum turbulent viscosity scales as νt,max = 0.030(B/N)1/2, where B is source buoyancy flux and N is ambient buoyancy frequency. These PIV data combined with previously published numerical simulation results have implications for understanding the roles of hydrothermal plume turbulence, i.e. plume turbulence within the cap region causes the 'plume-cap' entrainment that plays an equally important role as the 'plume-stem' entrainment in supplying the final volume flux at the plume spreading level.

  5. Predicted and observed cooling tower plume rise and visible plume length at the John E. Amos power plant

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, S R

    1976-01-01

    A one-dimensional numerical cloud growth model and several empirical models for plume rise and cloud growth are compared with twenty-seven sets of observations of cooling tower plumes from the 2900 MW John E. Amos power plant in West Virginia. The three natural draft cooling towers are 200 m apart. In a cross wind, the plumes begin to merge at a distance of about 500 m downwind. In calm conditions, with reduced entrainment, the plumes often do not merge until heights of 1000 m. The average plume rise, 750 m, is predicted well by the models, but day-to-day variations are simulated with a correlation coefficient of about 0.5. Model predictions of visible plume length agree, on the average, with observations for visible plumes of short to moderate length (less than about 1 km). The prediction of longer plumes is hampered by our lack of knowledge of plume spreading after the plumes level off. Cloud water concentrations predicted by the numerical model agree with those measured in natural cumulus clouds (about 0.1 to 1 g kg/sup -1/).

  6. Turbulent buoyant jets and plumes

    CERN Document Server

    Rodi, Wolfgang

    The Science & Applications of Heat and Mass Transfer: Reports, Reviews, & Computer Programs, Volume 6: Turbulent Buoyant Jets and Plumes focuses on the formation, properties, characteristics, and reactions of turbulent jets and plumes. The selection first offers information on the mechanics of turbulent buoyant jets and plumes and turbulent buoyant jets in shallow fluid layers. Discussions focus on submerged buoyant jets into shallow fluid, horizontal surface or interface jets into shallow layers, fundamental considerations, and turbulent buoyant jets (forced plumes). The manuscript then exami

  7. Volatile organic compounds composition of merged and aged forest fire plumes from Alaska and western Canada

    Science.gov (United States)

    de Gouw, J. A.; Warneke, C.; Stohl, A.; Wollny, A. G.; Brock, C. A.; Cooper, O. R.; Holloway, J. S.; Trainer, M.; Fehsenfeld, F. C.; Atlas, E. L.; Donnelly, S. G.; Stroud, V.; Lueb, A.

    2006-05-01

    The NOAA WP-3 aircraft intercepted aged forest fire plumes from Alaska and western Canada during several flights of the NEAQS-ITCT 2k4 mission in 2004. Measurements of acetonitrile (CH3CN) indicated that the air masses had been influenced by biomass burning. The locations of the plume intercepts were well described using emissions estimates and calculations with the transport model FLEXPART. The best description of the data was generally obtained when FLEXPART injected the forest fire emissions to high altitudes in the model. The observed plumes were generally drier than the surrounding air masses at the same altitude, suggesting that the fire plumes had been processed by clouds and that moisture had been removed by precipitation. Different degrees of photochemical processing of the plumes were determined from the measurements of aromatic VOCs. The removal of aromatic VOCs was slow considering the transport times estimated from the FLEXPART model. This suggests that the average OH levels were low during the transport, which may be explained by the low humidity and high concentrations of carbon monoxide and other pollutants. In contrast with previous work, no strong secondary production of acetone, methanol and acetic acid is inferred from the measurements. A clear case of removal of submicron particle volume and acetic acid due to precipitation scavenging was observed.

  8. Adaptive hierarchical grid model of water-borne pollutant dispersion

    Science.gov (United States)

    Borthwick, A. G. L.; Marchant, R. D.; Copeland, G. J. M.

    Water pollution by industrial and agricultural waste is an increasingly major public health issue. It is therefore important for water engineers and managers to be able to predict accurately the local behaviour of water-borne pollutants. This paper describes the novel and efficient coupling of dynamically adaptive hierarchical grids with standard solvers of the advection-diffusion equation. Adaptive quadtree grids are able to focus on regions of interest such as pollutant fronts, while retaining economy in the total number of grid elements through selective grid refinement. Advection is treated using Lagrangian particle tracking. Diffusion is solved separately using two grid-based methods; one is by explicit finite differences, the other a diffusion-velocity approach. Results are given in two dimensions for pure diffusion of an initially Gaussian plume, advection-diffusion of the Gaussian plume in the rotating flow field of a forced vortex, and the transport of species in a rectangular channel with side wall boundary layers. Close agreement is achieved with analytical solutions of the advection-diffusion equation and simulations from a Lagrangian random walk model. An application to Sepetiba Bay, Brazil is included to demonstrate the method with complex flows and topography.

  9. Atmospheric dispersion models for environmental pollution applications

    International Nuclear Information System (INIS)

    Gifford, F.A.

    1976-01-01

    Pollutants are introduced into the air by many of man's activities. The potentially harmful effects these can cause are, broadly speaking, of two kinds: long-term, possibly large-scale and wide-spread chronic effects, including long-term effects on the earth's climate; and acute, short-term effects such as those associated with urban air pollution. This section is concerned with mathematical cloud or plume models describing the role of the atmosphere, primarily in relation to the second of these, the acute effects of air pollution, i.e., those arising from comparatively high concentration levels. The need for such air pollution modeling studies has increased spectacularly as a result of the National Environmental Policy Act of 1968 and, especially, two key court decisions; the Calvert Cliffs decision, and the Sierra Club ruling on environmental non-degradation

  10. Plume rise from multiple sources

    International Nuclear Information System (INIS)

    Briggs, G.A.

    1975-01-01

    A simple enhancement factor for plume rise from multiple sources is proposed and tested against plume-rise observations. For bent-over buoyant plumes, this results in the recommendation that multiple-source rise be calculated as [(N + S)/(1 + S)]/sup 1/3/ times the single-source rise, Δh 1 , where N is the number of sources and S = 6 (total width of source configuration/N/sup 1/3/ Δh 1 )/sup 3/2/. For calm conditions a crude but simple method is suggested for predicting the height of plume merger and subsequent behavior which is based on the geometry and velocity variations of a single buoyant plume. Finally, it is suggested that large clusters of buoyant sources might occasionally give rise to concentrated vortices either within the source configuration or just downwind of it

  11. In situ airborne measurements of aerosol optical properties during photochemical pollution events

    Science.gov (United States)

    Mallet, M.; van Dingenen, R.; Roger, J. C.; Despiau, S.; Cachier, H.

    2005-02-01

    Dry aerosol optical properties (scattering, absorbing coefficients, and single scattering albedo) were derived from in situ airborne measurements during two photochemical pollution events (25 and 26 June) observed during the Experience sur Site pour Contraindre les Modeles de Pollution atmospherique et de Transport d'Emissions (ESCOMPTE) experiment. Two flights were carried out during daytime (one during the morning and one at noon) over a domain, allowing the investigation of how an air pollution event affects the particle optical properties. Both horizontal distribution and vertical profiles are presented. Results from the horizontal mapping show that plumes of enhanced scattering and absorption are formed in the planetary boundary layer (PBL) during the day in the sea breeze-driven outflow of the coastal urban-industrial area of Marseille-Fos de Berre. The domain-averaged scattering coefficient (at 550 nm) over land σs changes from 35 (28) Mm-1 during land breeze to 63 (43) Mm-1 during sea breeze on 25 June (26 June), with local maxima reaching > 100 Mm-1. The increase in the scattering coefficient is associated with new particle formation, indicative of secondary aerosol formation. Simultaneously, the domain-averaged absorption coefficient increases from 5.6 (3.4) Mm-1 to 9.3 (8.0) Mm-1. The pollution plume leads to strong gradients in the single scattering albedo ωo over the domain studied, with local values as low as 0.73 observed inside the pollution plume. The role of photochemistry and secondary aerosol formation during the 25 June case is shown to increase ωo and to make the aerosol more `reflecting' while the plume moves away from the sources. The lower photochemical activity, observed in the 26 June case, induces a relatively higher contribution of black carbon, making the aerosol more absorbing. Results from vertical profiles at a single near-urban location in the domain indicate that the changes in optical properties happen almost entirely within

  12. Brazil-USA Collaborative Research: Modifications by Anthropogenic Pollution of the Natural Atmospheric Chemistry and Particle Microphysics of the Tropical Rain Forest During the GoAmazon Intensive Operating Periods (IOPs)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Saewung [Univ. of California, Irvine, CA (United States)

    2017-08-01

    Manaus, a city of nearly two million people, represents an isolated urban area having a distinct urban pollution plume within the otherwise pristine Amazon Basin. The plume has high concentrations of oxides of nitrogen and sulfur, carbon monoxide, particle concentrations, and soot, among other pollutants. Critically, the distinct plume in the setting of the surrounding tropical rain forest serves as a natural laboratory to allow direct comparisons between periods of pollution influence to those of pristine conditions. The funded activity of this report is related to the Brazil-USA collaborative project during the two Intensive Operating Periods (wet season, 1 Feb - 31 Mar 2014; dry season, 15 Aug - 15 Oct 2014) of GoAmazon2014/5. The project addresses key science questions regarding the modification of the natural atmospheric chemistry and particle microphysics of the forest by present and future anthropogenic pollution.

  13. Climatological variability in regional air pollution

    International Nuclear Information System (INIS)

    Shannon, J.D.; Trexler, E.C. Jr.

    1995-01-01

    Although some air pollution modeling studies examine events that have already occurred (e.g., the Chernobyl plume) with relevant meteorological conditions largely known, most pollution modeling studies address expected or potential scenarios for the future. Future meteorological conditions, the major pollutant forcing function other than emissions, are inherently uncertain although much relevant information is contained in past observational data. For convenience in our discussions of regional pollutant variability unrelated to emission changes, we define meteorological variability as short-term (within-season) pollutant variability and climatological variability as year-to-year changes in seasonal averages and accumulations of pollutant variables. In observations and in some of our simulations the effects are confounded because for seasons of two different years both the mean and the within-season character of a pollutant variable may change. Effects of climatological and meteorological variability on means and distributions of air pollution parameters, particularly those related to regional visibility, are illustrated. Over periods of up to a decade climatological variability may mask or overstate improvements resulting from emission controls. The importance of including climatological uncertainties in assessing potential policies, particularly when based partly on calculated source-receptor relationships, is highlighted

  14. Modelling the transport of suspended particulate matter by the Rhone River plume (France). Implications for pollutant dispersion

    International Nuclear Information System (INIS)

    Perianez, R.

    2005-01-01

    A model to simulate the transport of suspended particulate matter by the Rhone River plume has been developed. The model solves the 3D hydrodynamic equations, including baroclinic terms and a 1-equation turbulence model, and the suspended matter equations including advection/diffusion of particles, settling and deposition. Four particle classes are considered simultaneously according to observations in the Rhone. Computed currents, salinity and particle distributions are, in general, in good agreement with observations or previous calculations. The model also provides sedimentation rates and the distribution of different particle classes over the sea bed. It has been found that high sedimentation rates close to the river mouth are due to coarse particles that sink rapidly. Computed sedimentation rates are also similar to those derived from observations. The model has been applied to simulate the transport of radionuclides by the plume, since suspended matter is the main vector for them. The radionuclide transport model, previously described and validated, includes exchanges of radionuclides between water, suspended matter and bottom sediment described in terms of kinetic rates. A new feature is the explicit inclusion of the dependence of kinetic rates upon salinity. The model has been applied to 137 Cs and 239,240 Pu. Results are, in general, in good agreement with observations. - A model has been developed to simulate transport of suspended particulate matter in the Rhone River plume

  15. Evaluation of plume potential and plume abatement of evaporative cooling towers in a subtropical region

    International Nuclear Information System (INIS)

    Xu Xinhua; Wang Shengwei; Ma Zhenjun

    2008-01-01

    Hong Kong is a typical subtropical region with frequently high humidity in late spring and summer seasons. Plume from evaporative cooling towers, which service air-conditioning systems of civil buildings, has aroused public concerns since 2000 when the fresh water evaporative cooling towers were allowed to be used for high energy efficiency and environmental issues. This paper presents the evaluation of the plume potential and its effect on the sizing of the plume abatement system in a large commercial office building in Hong Kong for practical application. This evaluation was conducted based on a dynamic simulation platform using the typical meteorological year of Hong Kong since the occurrence of the plume heavily depends on the state conditions of the exhaust air from cooling towers and the ambient air, while the state condition of the exhaust air is determined by the total building cooling load and the control strategies of cooling towers employed mainly for improving energy efficiency. The results show that the control strategies have a significant effect on the plume potential and further affect the system design and sizing of the plume abatement system

  16. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  17. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A G; Stordal, F; Knudsen, S [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1998-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  18. The Alberta smoke plume observation study

    Directory of Open Access Journals (Sweden)

    K. Anderson

    2018-02-01

    Full Text Available A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS. Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018 at http://cwfis.cfs.nrcan.gc.ca/datamart.

  19. The Alberta smoke plume observation study

    Science.gov (United States)

    Anderson, Kerry; Pankratz, Al; Mooney, Curtis; Fleetham, Kelly

    2018-02-01

    A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS). Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018) at http://cwfis.cfs.nrcan.gc.ca/datamart.

  20. Mercury Plumes in the Global Upper Troposphere Observed during Flights with the CARIBIC Observatory from May 2005 until June 2013

    Directory of Open Access Journals (Sweden)

    Franz Slemr

    2014-05-01

    Full Text Available Tropospheric sections of flights with the CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrumented Container observatory from May 2005 until June 2013, are investigated for the occurrence of plumes with elevated Hg concentrations. Additional information on CO, CO2, CH4, NOy, O3, hydrocarbons, halocarbons, acetone and acetonitrile enable us to attribute the plumes to biomass burning, urban/industrial sources or a mixture of both. Altogether, 98 pollution plumes with elevated Hg concentrations and CO mixing ratios were encountered, and the Hg/CO emission ratios for 49 of them could be calculated. Most of the plumes were found over East Asia, in the African equatorial region, over South America and over Pakistan and India. The plumes encountered over equatorial Africa and over South America originate predominantly from biomass burning, as evidenced by the low Hg/CO emission ratios and elevated mixing ratios of acetonitrile, CH3Cl and particle concentrations. The backward trajectories point to the regions around the Rift Valley and the Amazon Basin, with its outskirts, as the source areas. The plumes encountered over East Asia and over Pakistan and India are predominantly of urban/industrial origin, sometimes mixed with products of biomass/biofuel burning. Backward trajectories point mostly to source areas in China and northern India. The Hg/CO2 and Hg/CH4 emission ratios for several plumes are also presented and discussed.

  1. Large-Eddy Simulation of Chemically Reactive Pollutant Transport from a Point Source in Urban Area

    Science.gov (United States)

    Du, Tangzheng; Liu, Chun-Ho

    2013-04-01

    Most air pollutants are chemically reactive so using inert scalar as the tracer in pollutant dispersion modelling would often overlook their impact on urban inhabitants. In this study, large-eddy simulation (LES) is used to examine the plume dispersion of chemically reactive pollutants in a hypothetical atmospheric boundary layer (ABL) in neutral stratification. The irreversible chemistry mechanism of ozone (O3) titration is integrated into the LES model. Nitric oxide (NO) is emitted from an elevated point source in a rectangular spatial domain doped with O3. The LES results are compared well with the wind tunnel results available in literature. Afterwards, the LES model is applied to idealized two-dimensional (2D) street canyons of unity aspect ratio to study the behaviours of chemically reactive plume over idealized urban roughness. The relation among various time scales of reaction/turbulence and dimensionless number are analysed.

  2. Liquid Booster Module (LBM) plume flowfield model

    Science.gov (United States)

    Smith, S. D.

    1981-01-01

    A complete definition of the LBM plume is important for many Shuttle design criteria. The exhaust plume shape has a significant effect on the vehicle base pressure. The LBM definition is also important to the Shuttle base heating, aerodynamics and the influence of the exhaust plume on the launch stand and environment. For these reasons a knowledge of the LBM plume characteristics is necessary. A definition of the sea level LBM plume as well as at several points along the Shuttle trajectory to LBM, burnout is presented.

  3. Pollutant Removal, Dispersion and Entrainment over Two-Dimensional Idealized Street Canyons: an LES Approach

    Science.gov (United States)

    Wong, C.; Liu, C.

    2010-12-01

    Unlike pollutant transport over flat terrain, the mechanism and plume dispersion over urban areas is not well known. This study is therefore conceived to examine how urban morphology modifies the pollutant transport over urban areas. The computational domain and boundary condition used in this study is shown in Figure 1. The LES shows that inside the street canyon, the ground-level pollutants are carried to roof-level by the re-circulating flow, which are then removed from the street canyon to the UBL. Right above the roof level, narrow high-speed air masses in the streamwise flows and intensive downdrafts have been found in the shear layer. Different from the flows over a smooth surface, the maximum turbulence intensities descend that are peaked near the top of the building roughness. The pollutant is rather uniformly distributed inside a street canyon but disperses rapidly over the buildings exhibiting a Gaussian-plume form in the UBL. The mean component of vertical pollutant flux shows that the mean wind contributes to pollutant removal and entrainment simultaneously. Whereas, the fluctuating component demystifies that pollutant removal is mainly governed by atmospheric turbulence. Over the roof level, atmospheric flows slow down rapidly in the wake behind leeward building, suggesting the momentum entrainment into the street canyons. The decelerating streamwise flows in turn lead to upward flows carrying pollutants away from the street canyons, illustrating the basic pollutant removal mechanism in the skimming flow regime. Figure 1: Computational domain and boundary conditions Figure 2: Ensemble average vertical pollutant flux along the roof level. (a). Mean component; (b). turbulent component.

  4. Measurements on cooling tower plumes. Pt. 3

    International Nuclear Information System (INIS)

    Fortak, H.

    1975-11-01

    In this paper an extended field experiment is described in which cooling tower plumes were investigated by means of three-dimensional in situ measurements. The goal of this program was to obtain input data for numerical models of cooling tower plumes. Data for testing or developing assumptions for sub-grid parametrizations were of special interest. Utilizing modern systems for high-resolution aerology and small aircraft, four measuring campaigns were conducted: two campaigns (1974) at the cooling towers of the RWE power station at Neurath and also two (1975) at the single cooling tower of the RWE power station at Meppen. Because of the broad spectrum of weather situations, it can be assumed that the results are representative with regard to the interrelationship between the structure of cooling tower plumes and the large-scale meteorological situation. A large number of flights with a powered glider ASK 16 (more than 100 flight hours) crossing the plumes on orthogonal tracks was performed. All flights showed that the plume could be identified up to large downwind distances by discontinuous jumps of temperature and vapour pressure. Therefore a definite geometry of the plume could always be defined. In all cross sections a vertical circulation could be observed. At the plumes boundaries, which could be defined by the mentioned jumps of temperature and vapour pressure, a maximum of downward vertical motion was observed in most cases. Entrainment along the boundary of a cross section seems to be very small, except at the lower part of the plume. There, the mass entrainment is maximum and is responsible for plume rise as well as for enlargement of the cross section. The visible part of the plume (cloud) was only a small fraction of the whole plume. The discontinuities of temperature and vapour pressure show that the plume fills the space below the visible plume down to the ground. However, all effects decrease rapidly towards the ground. It turned out that high

  5. The impacts of changing transport and precipitation on pollutant distributions in a future climate

    Science.gov (United States)

    Fang, Yuanyuan; Fiore, Arlene M.; Horowitz, Larry W.; Gnanadesikan, Anand; Held, Isaac; Chen, Gang; Vecchi, Gabriel; Levy, Hiram

    2011-09-01

    Air pollution (ozone and particulate matter in surface air) is strongly linked to synoptic weather and thus is likely sensitive to climate change. In order to isolate the responses of air pollutant transport and wet removal to a warming climate, we examine a simple carbon monoxide-like (CO) tracer (COt) and a soluble version (SAt), both with the 2001 CO emissions, in simulations with the Geophysical Fluid Dynamics Laboratory chemistry-climate model (AM3) for present (1981-2000) and future (2081-2100) climates. In 2081-2100, projected reductions in lower-tropospheric ventilation and wet deposition exacerbate surface air pollution as evidenced by higher surface COt and SAt concentrations. However, the average horizontal general circulation patterns in 2081-2100 are similar to 1981-2000, so the spatial distribution of COt changes little. Precipitation is an important factor controlling soluble pollutant wet removal, but the total global precipitation change alone does not necessarily indicate the sign of the soluble pollutant response to climate change. Over certain latitudinal bands, however, the annual wet deposition change can be explained mainly by the simulated changes in large-scale (LS) precipitation. In regions such as North America, differences in the seasonality of LS precipitation and tracer burdens contribute to an apparent inconsistency of changes in annual wet deposition versus annual precipitation. As a step toward an ultimate goal of developing a simple index that can be applied to infer changes in soluble pollutants directly from changes in precipitation fields as projected by physical climate models, we explore here a "Diagnosed Precipitation Impact" (DPI) index. This index captures the sign and magnitude (within 50%) of the relative annual mean changes in the global wet deposition of the soluble pollutant. DPI can only be usefully applied in climate models in which LS precipitation dominates wet deposition and horizontal transport patterns change

  6. Radioactive Plumes Monitoring Simulator

    International Nuclear Information System (INIS)

    Kapelushnik, I.; Sheinfeld, M.; Avida, R.; Kadmon, Y.; Ellenbogen, M.; Tirosh, D.

    1999-01-01

    The Airborne Radiation Monitoring System (ARMS) monitors air or ground radioactive contamination. The contamination source can be a radioactive plume or an area contaminated with radionuclides. The system is based on two major parts, an airborne unit carried by a helicopter and a ground station carried by a truck. The system enables real time measurement and analysis of radioactive plumes as well as post flight processing. The Radioactive Plumes Monitoring Simulator purpose is to create a virtual space where the trained operators experience full radiation field conditions, without real radiation hazard. The ARMS is based on a flying platform and hence the simulator allows a significant reduction of flight time costs

  7. Investigation of Balcony Plume Entrainment

    OpenAIRE

    Liu, F.; Nielsen, Peter V.; Heiselberg, Per; Brohus, Henrik; Li, B. Z.

    2009-01-01

    An investigation on the scenarios of the spill plume and its equation was presented in this paper. The study includes two aspects, i.e., the small-scale experiment and the numerical simulation. Two balcony spill plume models are assessed by comparing with the FDS (Fire Dynamic Simulation) and small scale model experiment results. Besides validating the spill model by experiments, the effect of different fire location on balcony plume is also discussed.The results show that the balcony equatio...

  8. A Survey of Scattering, Attenuation, and Size Spectra Studies of Bubble Layers and Plumes Beneath the Air-Sea Interface.

    Science.gov (United States)

    1991-08-30

    soluble iron in the ocean [201] - a factor which may have global ecological implications since these creatures may account for a significant removal...submerged plateau) and seamount -dense environments. In these contexts the existing measurements in lakes and shallow water need follow-up work in...Studies of Bubble Layers and Plumes Beneath the Air-Sea Interface EDWARD POWELL Acoustic Svstems Branch Acoustics Division August 30, 1991 Si~ T 91-10188

  9. Investigating Rhône River plume (Gulf of Lions, France) dynamics using metrics analysis from the MERIS 300m Ocean Color archive (2002-2012)

    Science.gov (United States)

    Gangloff, Aurélien; Verney, Romaric; Doxaran, David; Ody, Anouck; Estournel, Claude

    2017-07-01

    In coastal environments, river plumes are major transport mechanisms for particulate matter, nutriments and pollutants. Ocean color satellite imagery is a valuable tool to explore river turbid plume characteristics, providing observations at high temporal and spatial resolutions of suspended particulate matter (SPM) concentration over a long time period, covering a wide range of hydro-meteorological conditions. We propose here to use the MERIS-FR (300m) Ocean Color archive (2002-2012) in order to investigate Rhône River turbid plume patterns generated by the two main forcings acting on the north-eastern part of the Gulf of Lions (France): wind and river freshwater discharge. Results are exposed considering plume metrics (area of extension, south-east-westernmost points, shape, centroid, SPM concentrations) extracted from satellite data using an automated image-processing tool. Rhône River turbid plume SPM concentrations and area of extension are shown to be mainly driven by the river outflow while wind direction acts on its shape and orientation. This paper also presents the region of influence of the Rhône River turbid plume over monthly and annual periods, and highlights its interannual variability.

  10. Are splash plumes the origin of minor hotspots?

    Science.gov (United States)

    Davies, J. H.; Bunge, H.-P.

    2006-05-01

    It has been claimed that focused hot cylindrical upwelling plumes cause many of the surface volcanic hotspots on Earth. It has also been argued that they must originate from thermal boundary layers. In this paper, we present spherical simulations of mantle circulation at close to Earth-like vigor with significant internal heating. These show, in addition to thermal boundary layer plumes, a new class of plumes that are not rooted in thermal boundary layers. These plumes develop as instabilities from the edge of bowls of hot mantle, which are produced by cold downwelling material deforming hot sheets of mantle. The resulting bowl and plume structure can look a bit like the “splash” of a water droplet. These splash plumes might provide an explanation for some hotspots that are not underlain by thermal boundary layer sourced plumes and not initiated by large igneous provinces. We suggest that in Earth's mantle, lithospheric instabilities or small pieces of subducting slab could play the role of the model downwelling material in initiating splash plumes. Splash plumes would have implications for interpreting ocean-island basalt geochemistry, plume fixity, excess plume temperature, and estimating core heat flux. Improved seismic imaging will ultimately test this hypothesis.

  11. Is the 'Fast Halo' around Hawaii as imaged in the PLUME experiment direct evidence for buoyant plume-fed asthenosphere?

    Science.gov (United States)

    Morgan, J. P.; Shi, C.; Hasenclever, J.

    2010-12-01

    An intriguing spatial pattern of variations in shear-wave arrival times has been mapped in the PLUME ocean bottom experiment (Wolfe et al., 2009) around Hawaii. The pattern consists of a halo of fast travel times surrounding a disk of slow arrivals from waves traveling up though the plume. We think it is directly sensing the pattern of dynamic uplift of the base of a buoyant asthenosphere - the buoyancy of the plume conduit lifting a 'rim' of the cooler, denser mantle that the plume rises through. The PLUME analysis inverted for lateral shear velocity variations beneath the lithosphere, after removing the assumed 1-D model velocity structure IASP91. They found that a slow plume-conduit extends to at least 1200 km below the Hawaiian hotspot. In this inversion the slow plume conduit is — quite surprisingly - surrounded by a fast wavespeed halo. A fast halo is impossible to explain as a thermal halo around the plume; this should lead to a slow wavespeed halo, not a fast one. Plume-related shearwave anisotropy also cannot simply explain this pattern — simple vertical strain around the plume conduit would result in an anisotropic slow shear-wavespeed halo, not a fast one. (Note the PLUME experiment’s uniform ‘fast-halo’ structure from 50-400km is likely to have strong vertical streaking in the seismic image; Pacific Plate-driven shear across a low-viscosity asthenosphere would be expected to disrupt and distort any cold sheet of vertical downwelling structure between 50-400km depths so that it would no longer be vertical as it is in the 2009 PLUME image with its extremely poor vertical depth control.) If the asthenosphere is plume-fed, hence more buoyant than underlying mantle, then there can be a simple explanation for this pattern. The anomaly would be due to faster traveltimes resulting from dynamic relief at the asthenosphere-mesosphere interface; uplift of the denser mesosphere by the buoyancy of the rising plume increases the distance a wave travels

  12. Preconditioning of model biocarriers by soluble pollutants: a QCM-D study.

    Science.gov (United States)

    Huang, Hui; Ding, Li-li; Ren, Hong-qiang; Geng, Jin-ju; Xu, Ke; Zhang, Yan

    2015-04-08

    Preconditioning of a biocarrier surface is the first step in triggering biofilm formation in attached-growth bioreactors. However, the quantification and control of this step as influenced by solution conditions and biocarrier properties have been rarely explored. In this paper, deposition behaviors of soluble pollutants on the model biocarriers polystyrene (PS) and polyamide (PA) were performed using a quartz crystal microbalance with dissipation monitoring (QCM-D). Three types of wastewater from municipal and industrial wastewater treatment plants and 12 synthetic wastewaters with different configurations of model macromolecules (bovine serum albumin and sodium alginate) and ionic compositions (Na(+) and Ca(2+)) were prepared. Results showed that high organic contents (protein and humic acid) in real wastewater increased deposition compared to the impact of ions on the two types of carriers. For synthetic wastewater, an interesting phenomenon was observed in that the presence of Ca(2+) can transform a thin and rigid adlayer into a denser and viscoelastic one on the surface of PS with low organic contents, yet a viscoelastic adlayer can directly form on PS and an increase in the ionic strength hinders deposition in the presence of high organic contents. The deposition of solutes on PA produces a thicker and viscoelastic adlayer that is strengthened an elevated concentration of organic materials. Additionally, a weakening effect of Ca(2+) on deposition was revealed under high ionic strength. This is the first demonstration of control strategies for preconditioning hydrophilic and hydrophobic biocarriers under different water quality conditions and has important implications for the design of a start-up process for biofilm formation in attached-growth bioreactors.

  13. Submarine Alkalic Lavas Around the Hawaiian Hotspot; Plume and Non-Plume Signatures Determined by Noble Gases

    Science.gov (United States)

    Hanyu, T.; Clague, D. A.; Kaneoka, I.; Dunai, T. J.; Davies, G. R.

    2004-12-01

    Noble gas isotopic ratios were determined for submarine alkalic volcanic rocks distributed around the Hawaiian islands to constrain the origin of such alkalic volcanism. Samples were collected by dredging or using submersibles from the Kauai Channel between Oahu and Kauai, north of Molokai, northwest of Niihau, Southwest Oahu, South Arch and North Arch volcanic fields. Sites located downstream from the center of the hotspot have 3He/4He ratios close to MORB at about 8 Ra, demonstrating that the magmas erupted at these sites had minimum contribution of volatiles from a mantle plume. In contrast, the South Arch, located upstream of the hotspot on the Hawaiian Arch, has 3He/4He ratios between 17 and 21 Ra, indicating a strong plume influence. Differences in noble gas isotopic characteristics between alkalic volcanism downstream and upstream of the hotspot imply that upstream volcanism contains incipient melts from an upwelling mantle plume, having primitive 3He/4He. In combination with lithophile element isotopic data, we conclude that the most likely source of the upstream magmatism is depleted asthenospheric mantle that has been metasomatised by incipient melt from a mantle plume. After major melt extraction from the mantle plume during production of magmas for the shield stage, the plume material is highly depleted in noble gases and moderately depleted in lithophile elements. Partial melting of the depleted mantle impregnated by melts derived from this volatile depleted plume source may explain the isotopic characteristics of the downstream alkalic magmatism.

  14. Intense atmospheric pollution modifies weather: a case of mixed biomass burning with fossil fuel combustion pollution in eastern China

    Science.gov (United States)

    Ding, A. J.; Fu, C. B.; Yang, X. Q.; Sun, J. N.; Petäjä, T.; Kerminen, V.-M.; Wang, T.; Xie, Y.; Herrmann, E.; Zheng, L. F.; Nie, W.; Liu, Q.; Wei, X. L.; Kulmala, M.

    2013-10-01

    The influence of air pollutants, especially aerosols, on regional and global climate has been widely investigated, but only a very limited number of studies report their impacts on everyday weather. In this work, we present for the first time direct (observational) evidence of a clear effect of how a mixed atmospheric pollution changes the weather with a substantial modification in the air temperature and rainfall. By using comprehensive measurements in Nanjing, China, we found that mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease in the solar radiation intensity by more than 70%, a decrease in the sensible heat by more than 85%, a temperature drop by almost 10 K, and a change in rainfall during both daytime and nighttime. Our results show clear air pollution-weather interactions, and quantify how air pollution affects weather via air pollution-boundary layer dynamics and aerosol-radiation-cloud feedbacks. This study highlights cross-disciplinary needs to investigate the environmental, weather and climate impacts of the mixed biomass burning and fossil fuel combustion sources in East China.

  15. Redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Downgradient from an old municipal landfill allowing leachate, rich in dissolved organic carbon, to enter a shallow sandy aerobic aquifer, a sequence of redoxe zones is identified from groundwater chemical analysis. Below the landfill, methanogenic conditions prevail, followed by sulfidogenic...... the fate of reactive pollutants leached from the landfill....

  16. Use of tritium to predict soluble pollutants transport in Ebro River waters (Spain).

    Science.gov (United States)

    Pujol, L; Sanchez-Cabeza, J A

    2000-05-01

    The Ebro River, in Northeast Spain, discharges into the Mediterranean Sea after flowing through several large cities and agricultural, mining and industrial areas. The Ascó nuclear power plant (NPP) is located in its lower section and comprises two pressurised water reactor units, from which low-level liquid radioactive waste is released to river waters under authority control. Tritium routinely released by the NPP was used as a radiotracer to determine the longitudinal dispersion coefficient and velocity of the river waters. Several field experiments, in co-ordination with the NPP, were carried out during 1991 and 1992. During each field experiment, the flow rate was kept constant by dams located upstream from the NPP. After each tritium release, water was sampled downstream at periodic intervals over several hours and tritium was measured with a low-background liquid scintillation counter. Velocity and dispersion coefficient were determined in river waters for several river discharges using an analytical, box-type and numerical approach to solve the one-dimensional advection-diffusion equation. The set of calibrated parameters was used to predict the displacement and dispersion of soluble pollutants in river waters. Velocity was determined as a function of river discharge and river slope, and dispersion coefficient was determined as a function of distance. Finally, sensitivity of the model predictions was studied and uncertainties of the fitted parameters were estimated.

  17. Computer code to assess accidental pollutant releases

    International Nuclear Information System (INIS)

    Pendergast, M.M.; Huang, J.C.

    1980-07-01

    A computer code was developed to calculate the cumulative frequency distributions of relative concentrations of an air pollutant following an accidental release from a stack or from a building penetration such as a vent. The calculations of relative concentration are based on the Gaussian plume equations. The meteorological data used for the calculation are in the form of joint frequency distributions of wind and atmospheric stability

  18. Abalone water-soluble matrix for self-healing biomineralization of tooth defects

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Zhenliang [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Chen, Jingdi, E-mail: ibptcjd@fzu.edu.cn [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Wang, Hailiang [The Affiliated Stomatological Hospital, Fujian Medical University, Fuzhou 350002 (China); Zhong, Shengnan; Hu, Yimin; Wang, Zhili [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Zhang, Qiqing, E-mail: zhangqiq@126.com [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin 300192 (China)

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% the abalone water-soluble protein (AWSPro) and 2.04 wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. - Graphical abstract: In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% abalone water-soluble protein (AWSPro) and 2.04 wt% abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro by self-organized. Display Omitted - Highlights: • Provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell. • The abalone shell water-soluble matrix contains protein and polysaccharide. • The abalone water-soluble matrix can efficiently induce remineralization of HAP by self-organized. • Achieved self-healing biomineralization of tooth defects in

  19. Abalone water-soluble matrix for self-healing biomineralization of tooth defects

    International Nuclear Information System (INIS)

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-01-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% the abalone water-soluble protein (AWSPro) and 2.04 wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. - Graphical abstract: In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53 wt% abalone water-soluble protein (AWSPro) and 2.04 wt% abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro by self-organized. Display Omitted - Highlights: • Provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell. • The abalone shell water-soluble matrix contains protein and polysaccharide. • The abalone water-soluble matrix can efficiently induce remineralization of HAP by self-organized. • Achieved self-healing biomineralization of tooth defects in vitro.

  20. Lithosphere erosion atop mantle plumes

    Science.gov (United States)

    Agrusta, R.; Arcay, D.; Tommasi, A.

    2012-12-01

    Mantle plumes are traditionally proposed to play an important role in lithosphere erosion. Seismic images beneath Hawaii and Cape Verde show a lithosphere-asthenosphere-boundary (LAB) up to 50 km shallower than the surroundings. However, numerical models show that unless the plate is stationary the thermo-mechanical erosion of the lithosphere does not exceed 30 km. We use 2D petrological-thermo-mechanical numerical models based on a finite-difference method on a staggered grid and marker in cell method to study the role of partial melting on the plume-lithosphere interaction. A homogeneous peridotite composition with a Newtonian temperature- and pressure-dependent viscosity is used to simulate both the plate and the convective mantle. A constant velocity, ranging from 5 to 12.5 cm/yr, is imposed at the top of the plate. Plumes are created by imposing a thermal anomaly of 150 to 350 K on a 50 km wide domain at the base of the model (700 km depth); the plate right above the thermal anomaly is 40 Myr old. Partial melting is modeled using batch-melting solidus and liquidus in anhydrous conditions. We model the progressive depletion of peridotite and its effect on partial melting by assuming that the melting degree only strictly increases through time. Melt is accumulated until a porosity threshold is reached and the melt in excess is then extracted. The rheology of the partially molten peridotite is determined using viscous constitutive relationship based on a contiguity model, which enables to take into account the effects of grain-scale melt distribution. Above a threshold of 1%, melt is instantaneously extracted. The density varies as a function of partial melting degree and extraction. Besides, we analyze the kinematics of the plume as it impacts a moving plate, the dynamics of time-dependent small-scale convection (SSC) instabilities developing in the low-viscosity layer formed by spreading of hot plume material at the lithosphere base, and the resulting thermal

  1. Plume rise measurements at Turbigo

    Energy Technology Data Exchange (ETDEWEB)

    Anfossi, D

    1982-01-01

    This paper presents analyses of plume measurements obtained during that campaign by the ENEL ground-based Lidar. The five stacks of Turbigo Power Plant have different heights and emission parameters and their plumes usually combine, so a model for multiple sources was used to predict the plume rises. These predictions are compared with the observations. Measurements of sigma/sub v/ and sigma/sub z/ over the first 1000 m are compared with the curves derived from other observations in the Po Valley, using the no-lift balloon technique over the same range of downwind distance. Skewness and kurtosis distributions are shown, both along the vertical and the horizontal directions. In order to show the plume structure in more detail, we present two examples of Lidar-derived cross sections and the corresponding vertically and horizontally integrated concentration profiles.

  2. NW Iberia shelf dynamics and the behaviour of the Douro River plume

    Science.gov (United States)

    Iglesias, Isabel; Couvelard, Xavier; Avilez-Valente, Paulo; Caldeira, Rui M. A.

    2015-04-01

    The study and modelling of the river plumes is a key factor to complete understand the coastal physics and dynamic processes and sediment transport mechanisms. Some the terrestrial materials that they transport to the ocean are pollutants, essential nutrients, which enhance the phytoplankton productivity or sediments, which settle on the seabed producing bathymetric modifications. When the riverine water join the ocean several instabilities can be induced, generating bulges, filaments, and buoyant currents over the continental shelf. Offshore, the riverine water could form fronts that could be related with the occurrence of current-jets, eddies and strong mixing. This study focused on the Douro River plume simulation. This river is located on the north-west Iberian coast. Its daily averaged freshwater discharge can range values from 0 to 13000 m3/s, which impacts on the formation of the river plumes and its dispersion along the continental shelf. The Regional Oceanic Modeling System (ROMS) model was used to reproduce scenarios of plume generation, retention and dispersion (Shchepetkin and McWilliams, 2005). Three types of simulations were performed: schematic winds simulations with prescribed river flow, wind speed and direction; multi-year climatological simulation, with river flow and temperature change for each month; extreme case simulation. The schematic wind case-studies suggest that the plume is wind-driven. Important differences appear in its structure and dispersion pathways depending on the wind direction and strength. Northerly winds induce plumes with a narrow coastal current meanwhile southerly winds push the river water to the north finding water associated with the Douro River in the Galician Rías. The high surface salinity on the plume regions during strong wind events suggests that the wind enhances the vertical mixing. Extreme river discharges, associated with southerly winds, can transport debris to the Galician coast in about 60 h, helping to

  3. Plume Dispersion over Idealized Urban-liked Roughness with Height Variation: an LES Approach

    Science.gov (United States)

    Wong, Colman Ching Chi; Liu, Chun-Ho

    2013-04-01

    Human activities (e.g. vehicular emission) are the primary pollutant sources affecting the health and living quality of stakeholders in modern compact cities. Gaussian plume dispersion model is commonly used for pollutant distribution estimate that works well over rural areas with flat terrain. However, its major parameters, dispersion coefficients, exclude the effect of surface roughness that unavoidably prone to error handling the pollutant transport in the urban boundary layer (UBL) over building roughness. Our recent large-eddy simulation (LES) has shown that urban surfaces affect significantly the pollutant dispersion over idealized, identical two-dimensional (2D) street canyons of uniform height. As an extension to our on-going effort, this study is conceived to investigate how rough urban surfaces, which are constructed by 2D street canyons of non-uniform height, modify the UBL pollutant dispersion . A series of LESs with idealized roughness elements of non-uniform heights were performed in neutral stratification. Building models with two different heights were placed alternatively in the computational domain to construct 2D street canyons in cross flows. The plume dispersion from a ground-level passive pollutant source over more realistic urban areas was then examined. Along with the existing building-height-to-street-width (aspect) ratio (AR), a new parameter, building-height variability (BHV), is used to measure the building height unevenness. Four ARs (1, 0.5, 0.25 and 0.125) and three BHVs (20%, 40% and 60%) were considered in this study. Preliminary results show that BHV greatly increases the aerodynamic roughness of the hypothetical urban surfaces for narrow street canyons. Analogous to our previous findings, the air exchange rate (ACH) of street canyons increases with increasing friction factor, implying that street-level ventilation could be improved by increasing building roughness via BHV. In addition, the parameters used in dispersion coefficient

  4. A stakeholder involvement approach to evaluate and enhance technology acceptance: U.S. Department of Energy Office of Technology Development's Plume Focus Area

    International Nuclear Information System (INIS)

    McCabe, G.H.; Stein, S.L.; Serie, P.J.

    1995-01-01

    The US Department of Energy (DOE) faces a major challenge in cleaning up its contaminated sites throughout the United States. One major area of concern is the plumes in soil and ground water which are contaminated with a myriad of different pollutants. DOE recently organized its plume-related problems into the Plume Focus Area. The mission of the Plume Focus Area is to enhance the deployment of innovative technologies for containing and cleaning up contaminant plumes in ground water and soil at all DOE sites. Environmental cleanup priorities for soil and ground water plumes are being defined and technology users have the challenge of matching current and innovative technologies to those priorities. By involving a range of stakeholders in the selection, demonstration, and evaluation of new technologies, the deployment of these technologies can be enhanced. If new plume cleanup technologies are to be deployable, they must improve on today's baseline technologies. The Sites' Coordination Team (SCT) of the Plume Focus Area develops and supports the implementation of methods for stakeholder involvement throughout the multiple steps that define focus area activities. Site-specific teams are being formed to carry out the strategy at each site, and the teams will work through Site Technology Coordination Groups (STCGs) at each location. The SCT is responsible for identifying the site-specific stakeholder involvement teams, training the team members, preparing needed national-level guidance and strategies, helping the teams tailor a strategy for their particular site that meets the overall needs of the focus area, and facilitating inter-site coordination. The results will be used to develop national technology acceptance reports on the innovative technologies being funded and evaluated under the Plume Focus Area

  5. Plume meander and dispersion in a stable boundary layer

    Science.gov (United States)

    Hiscox, April L.; Miller, David R.; Nappo, Carmen J.

    2010-11-01

    Continuous lidar measurements of elevated plume dispersion and corresponding micrometeorology data are analyzed to establish the relationship between plume behavior and nocturnal boundary layer dynamics. Contrasting nights of data from the JORNADA field campaign in the New Mexico desert are analyzed. The aerosol lidar measurements were used to separate the plume diffusion (plume spread) from plume meander (displacement). Mutiresolution decomposition was used to separate the turbulence scale (90 s). Durations of turbulent kinetic energy stationarity and the wind steadiness were used to characterize the local scale and submesoscale turbulence. Plume meander, driven by submesoscale wind motions, was responsible for most of the total horizontal plume dispersion in weak and variable winds and strong stability. This proportion was reduced in high winds (i.e., >4 m s-1), weakly stable conditions but remained the dominant dispersion mechanism. The remainder of the plume dispersion in all cases was accounted for by internal spread of the plume, which is a small eddy diffusion process driven by turbulence. Turbulence stationarity and the wind steadiness are demonstrated to be closely related to plume diffusion and plume meander, respectively.

  6. Experimental investigation of bubble plume structure instability

    Energy Technology Data Exchange (ETDEWEB)

    Marco Simiano; Robert Zboray; Francois de Cachard [Thermal-Hydraulics Laboratory, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Djamel Lakehal; George Yadigaroglu [Institute of Energy Technology, Swiss Federal Institute of Technology, ETH-Zentrum/CLT, 8092 Zurich (Switzerland)

    2005-07-01

    Full text of publication follows: The hydrodynamic properties of a 3D bubble plume in a large water pool are investigated experimentally. Bubble plumes are present in various industrial processes, including chemical plants, stirred reactors, and nuclear power plants, e.g. in BWR suppression pools. In these applications, the main issue is to predict the currents induced by the bubbles in the liquid phase, and to determine the consequent mixing. Bubble plumes, especially large and unconfined ones, present strong 3D effects and a superposition of different characteristic length scales. Thus, they represent relevant test cases for assessment and verification of 3D models in thermal-hydraulic codes. Bubble plumes are often unsteady, with fluctuations in size and shape of the bubble swarm, and global movements of the plume. In this case, local time-averaged data are not sufficient to characterize the flow. Additional information regarding changes in plume shape and position is required. The effect of scale on the 3D flow structure and stability being complex, there was a need to conduct studies in a fairly large facility, closer to industrial applications. Air bubble plumes, up to 30 cm in base diameter and 2 m in height were extensively studied in a 2 m diameter water pool. Homogeneously sized bubbles were obtained using a particular injector. The main hydrodynamic parameters. i.e., gas and liquid velocities, void fraction, bubble shape and size, plume shape and position, were determined experimentally. Photographic and image processing techniques were used to characterize the bubble shape, and double-tip optical probes to measure bubble size and void fraction. Electromagnetic probes measured the recirculation velocity in the pool. Simultaneous two-phase flow particle image velocimetry (STPFPIV) in a vertical plane containing the vessel axis provided instantaneous velocity fields for both phases and therefore the relative velocity field. Video recording using two CCD

  7. Chesapeake Bay plume dynamics from LANDSAT

    Science.gov (United States)

    Munday, J. C., Jr.; Fedosh, M. S.

    1981-01-01

    LANDSAT images with enhancement and density slicing show that the Chesapeake Bay plume usually frequents the Virginia coast south of the Bay mouth. Southwestern (compared to northern) winds spread the plume easterly over a large area. Ebb tide images (compared to flood tide images) show a more dispersed plume. Flooding waters produce high turbidity levels over the shallow northern portion of the Bay mouth.

  8. PLUME-MoM 1.0: A new integral model of volcanic plumes based on the method of moments

    Science.gov (United States)

    de'Michieli Vitturi, M.; Neri, A.; Barsotti, S.

    2015-08-01

    In this paper a new integral mathematical model for volcanic plumes, named PLUME-MoM, is presented. The model describes the steady-state dynamics of a plume in a 3-D coordinate system, accounting for continuous variability in particle size distribution of the pyroclastic mixture ejected at the vent. Volcanic plumes are composed of pyroclastic particles of many different sizes ranging from a few microns up to several centimeters and more. A proper description of such a multi-particle nature is crucial when quantifying changes in grain-size distribution along the plume and, therefore, for better characterization of source conditions of ash dispersal models. The new model is based on the method of moments, which allows for a description of the pyroclastic mixture dynamics not only in the spatial domain but also in the space of parameters of the continuous size distribution of the particles. This is achieved by formulation of fundamental transport equations for the multi-particle mixture with respect to the different moments of the grain-size distribution. Different formulations, in terms of the distribution of the particle number, as well as of the mass distribution expressed in terms of the Krumbein log scale, are also derived. Comparison between the new moments-based formulation and the classical approach, based on the discretization of the mixture in N discrete phases, shows that the new model allows for the same results to be obtained with a significantly lower computational cost (particularly when a large number of discrete phases is adopted). Application of the new model, coupled with uncertainty quantification and global sensitivity analyses, enables the investigation of the response of four key output variables (mean and standard deviation of the grain-size distribution at the top of the plume, plume height and amount of mass lost by the plume during the ascent) to changes in the main input parameters (mean and standard deviation) characterizing the

  9. Fossil plume head beneath the Arabian lithosphere?

    Science.gov (United States)

    Stein, Mordechai; Hofmann, Albrecht W.

    1992-12-01

    Phanerozoic alkali basalts from Israel, which have erupted over the past 200 Ma, have isotopic compositions similar to PREMA ("prevalent mantle") with narrow ranges of initial ɛ Nd(T) = +3.9-+5.9; 87Sr/ 86Sr(T)= 0.70292-0.70334; 206Pb/ 204Pb(T)= 18.88-19.99; 207Pb/ 204Pb(T)= 15.58-15.70; and 208Pb/ 204Pb(T)= 38.42-39.57. Their Nb/U(43 ± 9) and Ce/Pb(26 ± 6) ratios are identical to those of normal oceanic basalts, demonstrating that the basalts are essentially free of crustal contamination. Overall, the basalts are chemically and isotopically indistinguishable from many ordinary plume basalts, but no plume track can be identified. We propose that these and other, similar, magmas from the Arabian plate originated from a "fossilized" head of a mantle plume, which was unable to penetrate the continental lithosphere and was therefore trapped and stored beneath it. The plume head was emplaced some time between the late Proterozoic crust formation and the initiation of the Phanerozoic magmatic cycles. Basalts from rift environments in other continental localities show similar geochemistry to that of the Arabian basalts and their sources may also represent fossil plume heads trapped below the continents. We suggest that plume heads are, in general, characterized by the PREMA isotopic mantle signature, because the original plume sources (which may have HIMU or EM-type composition) have been diluted by overlying mantle material, which has been entrained by the plume heads during ascent. On the Arabian plate, rifting and thinning of the lithosphere caused partial melting of the stored plume, which led to periodic volcanism. In the late Cenozoic, the lithosphere broke up and the Red Sea opened. N-MORB tholeiites are now erupting in the central trough of the Red Sea, where the lithosphere has moved apart and the fossil plume has been exhausted, whereas E-MORBs are erupting in the northern and southern troughs, still tapping the plume reservoir. Fossil plumes, which are

  10. Intense atmospheric pollution modifies weather: a~case of mixed biomass burning with fossil fuel combustion pollution in the eastern China

    Science.gov (United States)

    Ding, A. J.; Fu, C. B.; Yang, X. Q.; Sun, J. N.; Petäjä, T.; Kerminen, V.-M.; Wang, T.; Xie, Y. N.; Herrmann, E.; Zheng, L. F.; Nie, W.; Wei, X. L.; Kulmala, M.

    2013-06-01

    The influence of air pollutants, particularly aerosols, on regional and global climate is widely investigated, but only a very limited number of studies reports their impacts on everyday weather. In this work, we present for the first time direct (observational) evidence of a clear effect how a mixed atmospheric pollution changes the weather with a substantial modification in air temperature and rainfall. By using comprehensive measurements in Nanjing, China, we found that mixed agricultural burning plumes with fossil fuel combustion pollution resulted in a decrease of solar radiation by more than 70%, of sensible heat flux over 85%, a temperature drop by almost 10 K, and a change of rainfall during daytime and nighttime. Our results show clear air pollution - weather interactions, and quantify how air pollution affects weather with the influence of air pollution-boundary layer dynamics and aerosol-radiation-cloudy feedbacks. This study highlights a cross-disciplinary needs to study the environmental, weather and climate impact of the mixed biomass burning and fossil fuel combustion sources in the East China.

  11. Buoyant plume calculations

    International Nuclear Information System (INIS)

    Penner, J.E.; Haselman, L.C.; Edwards, L.L.

    1985-01-01

    Smoke from raging fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in surface temperatures. However, the extent of the decrease and even the sign of the temperature change, depend on how the smoke is distributed with altitude. We present a model capable of evaluating the initial distribution of lofted smoke above a massive fire. Calculations are shown for a two-dimensional slab version of the model and a full three-dimensional version. The model has been evaluated by simulating smoke heights for the Hamburg firestorm of 1943 and a smaller scale oil fire which occurred in Long Beach in 1958. Our plume heights for these fires are compared to those predicted by the classical Morton-Taylor-Turner theory for weakly buoyant plumes. We consider the effect of the added buoyancy caused by condensation of water-laden ground level air being carried to high altitude with the convection column as well as the effects of background wind on the calculated smoke plume heights for several fire intensities. We find that the rise height of the plume depends on the assumed background atmospheric conditions as well as the fire intensity. Little smoke is injected into the stratosphere unless the fire is unusually intense, or atmospheric conditions are more unstable than we have assumed. For intense fires significant amounts of water vapor are condensed raising the possibility of early scavenging of smoke particles by precipitation. 26 references, 11 figures

  12. Constant volume balloons measurements in the urban Marseille and Fos-Berre industrial ozone plumes during ESCOMPTE experiment

    Science.gov (United States)

    Bénech, Bruno; Ezcurra, Agustin; Lothon, Marie; Saïd, Frédérique; Campistron, Bernard; Lohou, Fabienne; Durand, Pierre

    ESCOMPTE programme aims at studying the emissions of primary pollutants in industrial and urban areas, their transport, diffusion and transformation in the atmosphere. This experiment, carried out in southeast France, can be used to validate and to improve meteorological and chemical mesoscale models. One major goal of this experiment was to follow the pollutant plumes, and to investigate its thermodynamic and physico-chemical time evolution. This was realized by means of constant volume balloons, located by global position satellite (GPS) and equipped with thermodynamic and ozone sensors, flying at constant density levels. During the two ESCOMPTE campaigns that took place in June and July 2000 and 2001, 40 balloons were launched, 17 of them equipped with ozone sensors during the day from 0800 to 1800 UTC. Balloons' altitudes flight levels ranged between 400 and 1200 m altitude with Mistral (northerly synoptic flow) and Sea Breeze (southerly breeze) conditions. The atmospheric boundary layer (ABL) topography of the experimental domain is complex and varies strongly from day to day. Its depth presents a large gradient from the sea coast to the north part of the ESCOMPTE domain, and also more complex variability within the domain. The balloons' trajectories describe the evolution of the pollutant plume emitted from the industrial area of Fos-Berre or from the Marseille urban area. Constant volume balloons give a good description of the trajectories of these two plumes. The balloons, which fly at an isopicnic level, cross different atmospheric layers chiefly depending on the ABL height in relation with the constant volume balloons flight level. Thus, each balloon flight is decomposed into different segments that correspond to the same atmospheric layer. In each segment, the ozone content variation is analyzed in relation to other thermodynamical parameters measured by the balloon and mainly to the vapor mixing ratio content. During ESCOMPTE campaign, the mean linear

  13. PLUME and research sotware

    Science.gov (United States)

    Baudin, Veronique; Gomez-Diaz, Teresa

    2013-04-01

    The PLUME open platform (https://www.projet-plume.org) has as first goal to share competences and to value the knowledge of software experts within the French higher education and research communities. The project proposes in its platform the access to more than 380 index cards describing useful and economic software for this community, with open access to everybody. The second goal of PLUME focuses on to improve the visibility of software produced by research laboratories within the higher education and research communities. The "development-ESR" index cards briefly describe the main features of the software, including references to research publications associated to it. The platform counts more than 300 cards describing research software, where 89 cards have an English version. In this talk we describe the theme classification and the taxonomy of the index cards and the evolution with new themes added to the project. We will also focus on the organisation of PLUME as an open project and its interests in the promotion of free/open source software from and for research, contributing to the creation of a community of shared knowledge.

  14. Io Pele plume

    Science.gov (United States)

    2000-01-01

    Voyager 1 took this narrow-angle camera image on 5 March 1979 from a distance of 450,000 kilometers. At this geometry, the camera looks straight down through a volcanic plume at one of Io's most active volcanos, Pele. The large heart-shaped feature is the region where Pele's plume falls to the surface. At the center of the 'heart' is the small dark fissure that is the source of the eruption. The Voyager Project is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science.

  15. Io's Active Eruption Plumes: Insights from HST

    Science.gov (United States)

    Jessup, K. L.; Spencer, J. R.

    2011-10-01

    Taking advantage of the available data, we recently [10] completed a detailed analysis of the spectral signature of Io's Pele-type Tvashtar plume as imaged by the HST Wide Field and Planetary Camera 2 (HST/WFPC2) via absorption during Jupiter transit and via reflected sunlight in 2007, as well as HST/WFPC2 observations of the 1997 eruption of Io's Prometheus-type Pillan plume (Fig. 1). These observations were obtained in the 0.24-0.42 μm range, where the plumes gas absorption and aerosol scattering properties are most conspicuous. By completing a detailed analysis of these observations, several key aspects of the reflectance and the absorption properties of the two plumes have been revealed. Additionally, by considering the analysis of the HST imaging data in light of previously published spectral analysis of Io's Prometheus and Pele-type plumes several trends in the plume properties have been determined, allowing us to define the relative significance of each plume on the rate of re-surfacing occurring on Io and providing the measurements needed to better assess the role the volcanoes play in the stability of Io's tenuous atmosphere.

  16. Small rocket exhaust plume data

    Science.gov (United States)

    Chirivella, J. E.; Moynihan, P. I.; Simon, W.

    1972-01-01

    During recent cryodeposit tests with an 0.18-N thruster, the mass flux in the plume back field was measured for the first time for nitrogen, carbon dioxide, and a mixture of nitrogen, hydrogen, and ammonia at various inlet pressures. This mixture simulated gases that would be generated by a hydrazine plenum attitude propulsion system. The measurements furnish a base upon which to build a mathematical model of plume back flow that will be used in predicting the mass distribution in the boundary region of other plumes. The results are analyzed and compared with existing analytical predictions.

  17. A FUNDAMENTAL STUDY ON SOLUBILITY OF HEAVY METAL OXIDES IN AMMONIUM AND PHOSPHONIUM BASED DEEP EUTECTIC SOLVENTS

    Directory of Open Access Journals (Sweden)

    SHANGGARY RAJENDRAN

    2016-02-01

    Full Text Available Water pollution has become increasingly prevalent in our daily lives and has caused a serious threat at a global level. Among the various pollutants that exist,heavy metal pollution has become an issue of great concern due to their high toxicity, greater bioaccumulation in human body and food chain, nonbiodegradability nature, and carcinogenic effects to humans. This study aims to address the heavy metal ion contamination in wastewater by providing a low cost and efficient removal technique using DESs. In this investigation, the solubility of CuO and ZnO heavy metal oxide ions with concentration of 20g/L was studied in ammonium and phosphonium based DESs. The samples were left to stir at 250 rpm at 28, 45 and 65°C respectively for four hours in an incubator orbital shaker and the solubility of the heavy metal ions were analysed using Atomic Absorption Spectrometer (AAS using serial dilution technique. Phosphonium based DES which contain Methyl Triphenyl Phosphonium Bromide (MTPB showed higher solubility of CuO and ZnO ions. Based on the results obtained, DES 6 (MTPB: Glycerol has the highest solubility of CuO, 0.197 mg/L at 65°C and the solubility of ZnO was found to be the highest in DES 7 (MTPB: Glycerol, 1.225 mg/L at 65°C. Higher solubility was observed in samples containing ZnO as they are more ionic compared to CuO.

  18. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects....

  19. Environmental pollution by petroleum

    Energy Technology Data Exchange (ETDEWEB)

    Murata, T

    1974-06-01

    Pollution causes, cases, and remedies at various stages of petroleum production and usage are reviewed. Petroleum extraction (off-shore drilling and Arctic drilling) can be accompanied by mishaps. In 1971, IMCO (an international safety committee) proposed the partitioning of oil tanker holds into smaller compartments to minimize spillage in case of disaster. Although the solubility of oil in waste water from refineries is reckoned by ppM, the total amount dissolved is not negligible. Petroleum storage and transport on land is complicated by problems of safety in terms of population density as well as by pollution problems. Petroleum end-products such as plastic trash and automobile exhausts contribute to pollution. The role of aldehydes and peroxides in photochemical smog formation must be investigated further. Proper treatment of pollution at each specific point of occurrence, rather than at the end of a production line is recommended. Pollutant concentration for treatment, rather than pollutant dilution for dispersal, should be considered. Technology for pollution abatement is available, but not always economically feasible.

  20. Processes Influencing Ozone Levels in Alaskan Forest Fires Plumes during Long-Range Transport over the North Atlantic

    Science.gov (United States)

    Real, E.; Law, K. S.; Wienzierl, B.; Fiebig, M.; Petzold, A.; Wild, O.; Methven, J.; Arnold, S.; Stohl, A.; Huntrieser, H.; hide

    2006-01-01

    A case of long-range transport of a biomass burning plume from Alaska to Europe is analyzed using a Lagrangian approach. This plume was sampled several times in the free troposphere over North America, the North Atlantic and Europe by 3 different aircraft during the IGAC Lagrangian 2K4 experiment which was part of the ICARTT/ITOP measurement intensive in summer 2004. Measurements in the plume showed enhanced values of CO, VOCs and NOy, mainly in form of PAN. Observed O3 levels increased by 17 ppbv over 5 days. A photochemical trajectory model, CiTTyCAT, is used to examine processes responsible for the chemical evolution of the plume. The model was initialized with upwind data, and compared with downwind measurements. The influence of high aerosol loading on photolysis rates in the plume is investigated using in-situ aerosol measurements in the plume and lidar retrievals of optical depth as input into a photolysis code (Fast-J), run in the model. Significant impacts on photochemistry are found with a decrease of 18 percent in O3 production and 24 percent in O3 destruction over 5 days when including aerosols. The plume is found to be chemically active with large O3 increases attributed primarily to PAN decomposition during descent of the plume towards Europe. The predicted O3 changes are very dependent on temperature changes during transport, and also, on water vapor levels in the lower troposphere which can lead to O3 destruction. Simulation of mixing/dilution was necessary to reproduce observed pollutants level in the plume. Mixing was simulated using background concentrations from measurements in air masses in close proximity to the plume, and mixing timescales (averaging 6.25 days) were derived from CO changes. Observed and simulated O3/CO correlations in the plume are also compared in order to evaluate the photochemistry in the model. Observed slopes changed from negative to positive over 5 days. This change, which can be attributed largely to photochemistry, is

  1. Galileo observations of volcanic plumes on Io

    Science.gov (United States)

    Geissler, P.E.; McMillan, M.T.

    2008-01-01

    Io's volcanic plumes erupt in a dazzling variety of sizes, shapes, colors and opacities. In general, the plumes fall into two classes, representing distinct source gas temperatures. Most of the Galileo imaging observations were of the smaller, more numerous Prometheus-type plumes that are produced when hot flows of silicate lava impinge on volatile surface ices of SO2. Few detections were made of the giant, Pele-type plumes that vent high temperature, sulfur-rich gases from the interior of Io; this was partly because of the insensitivity of Galileo's camera to ultraviolet wavelengths. Both gas and dust spout from plumes of each class. Favorably located gas plumes were detected during eclipse, when Io was in Jupiter's shadow. Dense dust columns were imaged in daylight above several Prometheus-type eruptions, reaching heights typically less than 100 km. Comparisons between eclipse observations, sunlit images, and the record of surface changes show that these optically thick dust columns are much smaller in stature than the corresponding gas plumes but are adequate to produce the observed surface deposits. Mie scattering calculations suggest that these conspicuous dust plumes are made up of coarse grained “ash” particles with radii on the order of 100 nm, and total masses on the order of 106 kg per plume. Long exposure images of Thor in sunlight show a faint outer envelope apparently populated by particles small enough to be carried along with the gas flow, perhaps formed by condensation of sulfurous “snowflakes” as suggested by the plasma instrumentation aboard Galileo as it flew through Thor's plume [Frank, L.A., Paterson, W.R., 2002. J. Geophys. Res. (Space Phys.) 107, doi:10.1029/2002JA009240. 31-1]. If so, the total mass of these fine, nearly invisible particles may be comparable to the mass of the gas, and could account for much of Io's rapid resurfacing.

  2. Measurements of radiological background and some chemical pollutants in two areas of greater cairo

    International Nuclear Information System (INIS)

    Tawfik, F.S.; Ramadan, A.; Abdel Aziz, M.A.; Aly, A.I.M.

    2002-01-01

    The present work aims to the evaluation of radiological background levels and chemical pollutants in greater cairo as the most dense populated city in Egypt. The meteorological data of a complete one year of Cairo city have been collected, investigated and processed to determined the behavior of the pollutants in the atmosphere and the sector that is strongly affected by the pollutants. Portable detector for measuring the radiological background was deployed in Nasr City, where two nuclear centers belonging to Atomic Energy Authority are located, to measure the radioactivity levels in the atmosphere and compare them with the international standard limits. Other detectors were deployed in Shobra El- Khema area to study two significant phenomena, the first is the formation of ozone through the photo-chemical oxidation, its level and its behavior in the atmosphere, taking into consideration the international standard limits. The second phenomenon is the impact of the black plume on the capital Cairo started on October (1999) and its association of pollutant levels increment, defining the nature and the site location of the pollutant source. The carbon monoxide concentrations (as an example), before and during the black plume, were calculated using Gaussian equation then compared with the measured data in Shobra El- Khema region. The other available instruments were used to measure nitrogen oxides, ozone and carbon monoxide

  3. Rise of a cold plume

    International Nuclear Information System (INIS)

    Kakuta, Michio

    1977-06-01

    The rise of smoke from the stacks of two research reactors in normal operation was measured by photogrametric method. The temperature of effluent gas is less than 20 0 C higher than that of the ambient air (heat emission of the order 10 4 cal s -1 ), and the efflux velocity divided by the wind speed is between 0.5 and 2.8 in all 16 smoke runs. The field data obtained within downwind distance of 150m are compared with those by plume rise formulas presently available. Considering the shape of bending-over plume, the Briggs' formula for 'jet' gives a reasonable explanation of the observed plume rise. (auth.)

  4. PLUME-MoM 1.0: a new 1-D model of volcanic plumes based on the method of moments

    Science.gov (United States)

    de'Michieli Vitturi, M.; Neri, A.; Barsotti, S.

    2015-05-01

    In this paper a new mathematical model for volcanic plumes, named PlumeMoM, is presented. The model describes the steady-state 1-D dynamics of the plume in a 3-D coordinate system, accounting for continuous variability in particle distribution of the pyroclastic mixture ejected at the vent. Volcanic plumes are composed of pyroclastic particles of many different sizes ranging from a few microns up to several centimeters and more. Proper description of such a multiparticle nature is crucial when quantifying changes in grain-size distribution along the plume and, therefore, for better characterization of source conditions of ash dispersal models. The new model is based on the method of moments, which allows description of the pyroclastic mixture dynamics not only in the spatial domain but also in the space of properties of the continuous size-distribution of the particles. This is achieved by formulation of fundamental transport equations for the multiparticle mixture with respect to the different moments of the grain-size distribution. Different formulations, in terms of the distribution of the particle number, as well as of the mass distribution expressed in terms of the Krumbein log scale, are also derived. Comparison between the new moments-based formulation and the classical approach, based on the discretization of the mixture in N discrete phases, shows that the new model allows the same results to be obtained with a significantly lower computational cost (particularly when a large number of discrete phases is adopted). Application of the new model, coupled with uncertainty quantification and global sensitivity analyses, enables investigation of the response of four key output variables (mean and standard deviation (SD) of the grain-size distribution at the top of the plume, plume height and amount of mass lost by the plume during the ascent) to changes in the main input parameters (mean and SD) characterizing the pyroclastic mixture at the base of the plume

  5. Rebound of a coal tar creosote plume following partial source zone treatment with permanganate.

    Science.gov (United States)

    Thomson, N R; Fraser, M J; Lamarche, C; Barker, J F; Forsey, S P

    2008-11-14

    The long-term management of dissolved plumes originating from a coal tar creosote source is a technical challenge. For some sites stabilization of the source may be the best practical solution to decrease the contaminant mass loading to the plume and associated off-site migration. At the bench-scale, the deposition of manganese oxides, a permanganate reaction byproduct, has been shown to cause pore plugging and the formation of a manganese oxide layer adjacent to the non-aqueous phase liquid creosote which reduces post-treatment mass transfer and hence mass loading from the source. The objective of this study was to investigate the potential of partial permanganate treatment to reduce the ability of a coal tar creosote source zone to generate a multi-component plume at the pilot-scale over both the short-term (weeks to months) and the long-term (years) at a site where there is >10 years of comprehensive synoptic plume baseline data available. A series of preliminary bench-scale experiments were conducted to support this pilot-scale investigation. The results from the bench-scale experiments indicated that if sufficient mass removal of the reactive compounds is achieved then the effective solubility, aqueous concentration and rate of mass removal of the more abundant non-reactive coal tar creosote compounds such as biphenyl and dibenzofuran can be increased. Manganese oxide formation and deposition caused an order-of-magnitude decrease in hydraulic conductivity. Approximately 125 kg of permanganate were delivered into the pilot-scale source zone over 35 days, and based on mass balance estimates 35% reduction for all monitored compounds except for biphenyl, dibenzofuran and fluoranthene 150 days after treatment, which is consistent with the bench-scale experimental results. Pre- and post-treatment soil core data indicated a highly variable and random spatial distribution of mass within the source zone and provided no insight into the mass removed of any of the

  6. The effect of coal-fired power-plant SO2 and NOx control technologies on aerosol nucleation in the source plumes

    Directory of Open Access Journals (Sweden)

    E. M. Knipping

    2012-12-01

    Full Text Available Nucleation in coal-fired power-plant plumes can greatly contribute to particle number concentrations near source regions. The changing emissions rates of SO2 and NOx due to pollution-control technologies over recent decades may have had a significant effect on aerosol formation and growth in the plumes with ultimate implications for climate and human health. We use the System for Atmospheric Modeling (SAM large-eddy simulation model with the TwO-Moment Aerosol Sectional (TOMAS microphysics algorithm to model the nucleation in plumes of coal-fired plants. We test a range of cases with varying emissions to simulate the implementation of emissions-control technologies between 1997 and 2010. We start by simulating the W. A. Parish power plant (near Houston, TX during this time period, when NOx emissions were reduced by ~90% and SO2 emissions decreased by ~30%. Increases in plume OH (due to the reduced NOx produced enhanced SO2 oxidation and an order-of-magnitude increase in particle nucleation in the plume despite the reduction in SO2 emissions. These results suggest that NOx emissions could strongly regulate particle nucleation and growth in power-plant plumes. Next, we test a range of cases with varying emissions to simulate the implementation of SO2 and NOx emissions-control technologies. Particle formation generally increases with SO2 emission, while NOx shows two different regimes: increasing particle formation with increasing NOx under low-NOx emissions and decreasing particle formation with increasing NOx under high-NOx emissions. Next, we compare model results with airborne measurements made in the W. A. Parish power-plant plume in 2000 and 2006, confirming the importance of NOx emissions on new particle formation and highlighting the substantial effect of background aerosol loadings on this process (the more polluted background of the 2006 case caused more than an order-of-magnitude reduction in particle formation in the plume compared to

  7. Forest fires in Himalayan region during 2016 - Aerosol load and smoke plume heights detection by multi sensor observations

    Science.gov (United States)

    Kumar, S.; Dumka, U. C.

    2017-12-01

    The forest fires are common events over the Central Himalayan region during the pre-monsoon season (March - June) of every year. Forest fire plays a crucial role in governing the vegetation structure, ecosystem, climate change as well as in atmospheric chemistry. In regional and global scales, the combustion of forest and grassland vegetation releases large volumes of smoke, aerosols, and other chemically active species that significantly influence Earth's radiative budget and atmospheric chemistry, impacting air quality and risks to human health. During the year 2016, massive forest fires have been recorded over the Central Himalayan region of Uttarakhand which continues for several weeks. To study this event we used the multi-satellite observations of aerosols and pollutants during pre-fire, fire and post-fire period over the central Himalayan region. The data used in this study are active fire count and aerosol optical depth (AOD) from MODerate-resolution Imaging Spectroradiometer (MODIS), aerosol index and gases pollutants from Ozone Monitoring Instrument (OMI), along with vertical profiles of aerosols and smoke plume height information from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The result shows that the mean fire counts were maximum in April. The daily average AOD value shows an increasing trend during the fire events. The mean value of AOD before the massive fire (25 April), during the fire (30 April) and post fire (5 May) periods are 0.3, 1.2 and 0.6 respectively. We find an increasing trend of total columnar NO2 over the Uttarakhand region during the massive fire event. Space-born Lidar (CALIPSO) retrievals show the extent of smoke plume heights beyond the planetary boundary layer up to 6 km during the peak burning day (April 30). The HYSPLIT air mass forward trajectory shows the long-range transportation of smoke plumes. The results of the present study provide valuable information for addressing smoke plume and

  8. A numerical study of the Magellan Plume

    Science.gov (United States)

    Palma, Elbio D.; Matano, Ricardo P.

    2012-05-01

    In this modeling study we investigate the dynamical mechanisms controlling the spreading of the Magellan Plume, which is a low-salinity tongue that extends along the Patagonian Shelf. Our results indicate that the overall characteristics of the plume (width, depth, spreading rate, etc.) are primarily influenced by tidal forcing, which manifests through tidal mixing and tidal residual currents. Tidal forcing produces a homogenization of the plume's waters and an offshore displacement of its salinity front. The interaction between tidal and wind-forcing reinforces the downstream and upstream buoyancy transports of the plume. The influence of the Malvinas Current on the Magellan Plume is more dominant north of 50°S, where it increases the along-shelf velocities and generates intrusions of saltier waters from the outer shelf, thus causing a reduction of the downstream buoyancy transport. Our experiments also indicate that the northern limit of the Magellan Plume is set by a high salinity discharge from the San Matias Gulf. Sensitivity experiments show that increments of the wind stress cause a decrease of the downstream buoyancy transport and an increase of the upstream buoyancy transport. Variations of the magnitude of the discharge produce substantial modifications in the downstream penetration of the plume and buoyancy transport. The Magellan discharge generates a northeastward current in the middle shelf, a recirculation gyre south of the inlet and a region of weak currents father north.

  9. Reservoir operation schemes for water pollution accidents in Yangtze River

    Directory of Open Access Journals (Sweden)

    Xiao-kang Xin

    2012-03-01

    Full Text Available After the Three Gorges Reservoir starts running, it can not only take into consideration the interest of departments such as flood control, power generation, water supply, and shipping, but also reduce or eliminate the adverse effects of pollutants by discharge regulation. The evolution of pollutant plumes under different operation schemes of the Three Gorges Reservoir and three kinds of pollutant discharge types were calculated with the MIKE 21 AD software. The feasibility and effectiveness of the reservoir emergency operation when pollution accidents occur were investigated. The results indicate that the emergency operation produces significant effects on the instantaneous discharge type with lesser effects on the constant discharge type, the impact time is shortened, and the concentration of pollutant is reduced. Meanwhile, the results show that the larger the discharge is and the shorter the operation duration is, the more favorable the result is.

  10. Ocean outfall plume characterization using an Autonomous Underwater Vehicle.

    Science.gov (United States)

    Rogowski, Peter; Terrill, Eric; Otero, Mark; Hazard, Lisa; Middleton, William

    2013-01-01

    A monitoring mission to map and characterize the Point Loma Ocean Outfall (PLOO) wastewater plume using an Autonomous Underwater Vehicle (AUV) was performed on 3 March 2011. The mobility of an AUV provides a significant advantage in surveying discharge plumes over traditional cast-based methods, and when combined with optical and oceanographic sensors, provides a capability for both detecting plumes and assessing their mixing in the near and far-fields. Unique to this study is the measurement of Colored Dissolved Organic Matter (CDOM) in the discharge plume and its application for quantitative estimates of the plume's dilution. AUV mission planning methodologies for discharge plume sampling, plume characterization using onboard optical sensors, and comparison of observational data to model results are presented. The results suggest that even under variable oceanic conditions, properly planned missions for AUVs equipped with an optical CDOM sensor in addition to traditional oceanographic sensors, can accurately characterize and track ocean outfall plumes at higher resolutions than cast-based techniques.

  11. The evolution of photochemical smog in a power plant plume

    Science.gov (United States)

    Luria, Menachem; Valente, Ralph J.; Tanner, Roger L.; Gillani, Noor V.; Imhoff, Robert E.; Mueller, Stephen F.; Olszyna, Kenneth J.; Meagher, James F. Present address: Aeronomy Laboratory, NOAA, 325 Broadway, Boulder CO 80303, USA.)

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism.

  12. The evolution of photochemical smog in a power plant plume

    International Nuclear Information System (INIS)

    Luria, M.; The Hebrew University, Jerusalem; Valente, R.J.; Tanner, R.L.; Imhoff, R.E.; Mueller, S.F.; Olszyna, K.J.; Meagher, J.F.; Gillani, N.V.; University of Alabama, Huntsville, AL

    1999-01-01

    The evolution of photochemical smog in a plant plume was investigated with the aid of an instrumented helicopter. Air samples were taken in the plume of the Cumberland Power Plant, located in central Tennessee, during the afternoon of 16 July 1995 as part of the Southern Oxidants Study - Nashville Middle Tennessee Ozone Study. Twelve cross-wind air sampling traverses were made at six distance groups from 35 to 116 km from the source. During the sampling period the winds were from the west-northwest and the plume drifted towards the city of Nashville TN. Ten of the traverses were made upwind of the city, where the power plant plume was isolated, and two traverses downwind of the city when the plumes were possibly mixed. The results revealed that even six hours after the release, excess ozone production was limited to the edges of the plume. Only when the plume was sufficiently dispersed, but still upwind of Nashville, was excess ozone (up to 109 ppbv, 50-60 ppbv above background levels) produced in the center of the plume. The concentrations image of the plume and a Lagrangian particle model suggests that portions of the power plant plume mixed with the urban plume. The mixed urban power plant plume began to regenerate O 3 that peaked at 120 ppbv at a short distance (15-25 km) downwind of Nashville. Ozone productivity (the ratio of excess O 3 to NO y and NO z ) in the isolated plume was significantly lower compared with that found in the city plume. The production of nitrate, a chain termination product, was significantly higher in the power plant plume compared to the mixed plume, indicating shorter chain length of the photochemical smog chain reaction mechanism. (author)

  13. Plume structure in high-Rayleigh-number convection

    Science.gov (United States)

    Puthenveettil, Baburaj A.; Arakeri, Jaywant H.

    2005-10-01

    Near-wall structures in turbulent natural convection at Rayleigh numbers of 10^{10} to 10^{11} at A Schmidt number of 602 are visualized by a new method of driving the convection across a fine membrane using concentration differences of sodium chloride. The visualizations show the near-wall flow to consist of sheet plumes. A wide variety of large-scale flow cells, scaling with the cross-section dimension, are observed. Multiple large-scale flow cells are seen at aspect ratio (AR)= 0.65, while only a single circulation cell is detected at AR= 0.435. The cells (or the mean wind) are driven by plumes coming together to form columns of rising lighter fluid. The wind in turn aligns the sheet plumes along the direction of shear. the mean wind direction is seen to change with time. The near-wall dynamics show plumes initiated at points, which elongate to form sheets and then merge. Increase in rayleigh number results in a larger number of closely and regularly spaced plumes. The plume spacings show a common log normal probability distribution function, independent of the rayleigh number and the aspect ratio. We propose that the near-wall structure is made of laminar natural-convection boundary layers, which become unstable to give rise to sheet plumes, and show that the predictions of a model constructed on this hypothesis match the experiments. Based on these findings, we conclude that in the presence of a mean wind, the local near-wall boundary layers associated with each sheet plume in high-rayleigh-number turbulent natural convection are likely to be laminar mixed convection type.

  14. DSMC Simulations of Io's Pele Plume

    Science.gov (United States)

    McDoniel, William; Goldstein, D.; Varghese, P.; Trafton, L.

    2012-10-01

    Io’s Pele plume rises over 300km in altitude and leaves a deposition ring 1200km across on the surface of the moon. Material emerges from an irregularly-shaped vent, and this geometry gives rise to complex 3D flow features. The Direct Simulation Monte Carlo method is used to model the gas flow in the rarefied plume, demonstrating how the geometry of the source region is responsible for the asymmetric structure of the deposition ring and illustrating the importance of very small-scale vent geometry in explaining large observed features of interest. Simulations of small particles in the plume and comparisons to the black “butterfly wings” seen at Pele are used to constrain particle sizes and entrainment mechanisms. Preliminary results for the effects of plasma energy and momentum transfer to the plume will also be presented.

  15. Source-term development for a contaminant plume for use by multimedia risk assessment models

    International Nuclear Information System (INIS)

    Whelan, Gene; McDonald, John P.; Taira, Randal Y.; Gnanapragasam, Emmanuel K.; Yu, Charley; Lew, Christine S.; Mills, William B.

    1999-01-01

    Multimedia modelers from the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) are collaborating to conduct a comprehensive and quantitative benchmarking analysis of four intermedia models: DOE's Multimedia Environmental Pollutant Assessment System (MEPAS), EPA's MMSOILS, EPA's PRESTO, and DOE's RESidual RADioactivity (RESRAD). These models represent typical analytically, semi-analytically, and empirically based tools that are utilized in human risk and endangerment assessments for use at installations containing radioactive and/or hazardous contaminants. Although the benchmarking exercise traditionally emphasizes the application and comparison of these models, the establishment of a Conceptual Site Model (CSM) should be viewed with equal importance. This paper reviews an approach for developing a CSM of an existing, real-world, Sr-90 plume at DOE's Hanford installation in Richland, Washington, for use in a multimedia-based benchmarking exercise bet ween MEPAS, MMSOILS, PRESTO, and RESRAD. In an unconventional move for analytically based modeling, the benchmarking exercise will begin with the plume as the source of contamination. The source and release mechanism are developed and described within the context of performing a preliminary risk assessment utilizing these analytical models. By beginning with the plume as the source term, this paper reviews a typical process and procedure an analyst would follow in developing a CSM for use in a preliminary assessment using this class of analytical tool

  16. Paducah Gaseous Diffusion Plant Northwest Plume interceptor system evaluation

    International Nuclear Information System (INIS)

    Laase, A.D.; Clausen, J.L.

    1998-01-01

    The Paducah Gaseous Diffusion Plant (PGDP) recently installed an interceptor system consisting of four wells, evenly divided between two well fields, to contain the Northwest Plume. As stated in the Northwest Plume Record of Decision (ROD), groundwater will be pumped at a rate to reduce further contamination and initiate control of the northwest contaminant plume. The objective of this evaluation was to determine the optimum (minimal) well field pumping rates required for plume hotspot containment. Plume hotspot, as defined in the Northwest Plume ROD and throughout this report, is that portion of the plume with trichloroethene (TCE) concentrations greater than 1,000 microg/L. An existing 3-dimensional groundwater model was modified and used to perform capture zone analyses of the north and south interceptor system well fields. Model results suggest that the plume hotspot is not contained at the system design pumping rate of 100 gallons per minute (gal/min) per well field. Rather, the modeling determined that north and south well field pumping rates of 400 and 150 gal/min, respectively, are necessary for plume hotspot containment. The difference between the design and optimal pumping rates required for containment can be attributed to the discovery of a highly transmissive zone in the vicinity of the two well fields

  17. Follow the plume: the habitability of Enceladus.

    Science.gov (United States)

    McKay, Christopher P; Anbar, Ariel D; Porco, Carolyn; Tsou, Peter

    2014-04-01

    The astrobiological exploration of other worlds in our Solar System is moving from initial exploration to more focused astrobiology missions. In this context, we present the case that the plume of Enceladus currently represents the best astrobiology target in the Solar System. Analysis of the plume by the Cassini mission indicates that the steady plume derives from a subsurface liquid water reservoir that contains organic carbon, biologically available nitrogen, redox energy sources, and inorganic salts. Furthermore, samples from the plume jetting out into space are accessible to a low-cost flyby mission. No other world has such well-studied indications of habitable conditions. Thus, the science goals that would motivate an Enceladus mission are more advanced than for any other Solar System body. The goals of such a mission must go beyond further geophysical characterization, extending to the search for biomolecular evidence of life in the organic-rich plume. This will require improved in situ investigations and a sample return.

  18. Brazil-USA Collaborative Research: Modifications by Anthropogenic Pollution of the Natural Atmospheric Chemistry and Particle Microphysics of the Tropical Rain Forest During the GoAmazon Intensive Operating Periods (IOPs)

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Jose-Luis [Univ. of Colorado, Boulder, CO (United States); Day, Douglas A. [Univ. of Colorado, Boulder, CO (United States); Martin, Scot T. [Univ. of Colorado, Boulder, CO (United States); Kim, Saewung [Univ. of Colorado, Boulder, CO (United States); Smith, James [Univ. of Colorado, Boulder, CO (United States); Souza, Rodrigo [Univ. of Colorado, Boulder, CO (United States); Barbosa, Henry [Univ. of Colorado, Boulder, CO (United States)

    2017-08-04

    Manaus, a city of nearly two million people, represents an isolated urban area having a distinct urban pollution plume within the otherwise pristine Amazon Basin. The plume has high concentrations of oxides of nitrogen and sulfur, carbon monoxide, particle concentrations, and soot, among other pollutants. Critically, the distinct plume in the setting of the surrounding tropical rain forest serves as a natural laboratory to allow direct comparisons between periods of pollution influence to those of pristine conditions. The funded activity of this report is related to the Brazil-USA collaborative project during the two Intensive Operating Periods (wet season, 1 Feb - 31 Mar 2014; dry season, 15 Aug - 15 Oct 2014) of GoAmazon2014/5. The project addresses key science questions regarding the modification of the natural atmospheric chemistry and particle microphysics of the forest by present and future anthropogenic pollution. The first objective of the project was to understand and quantify the interactions of biogenic and anthropogenic emissions with respect to the production of secondary organic material. In clean conditions in the Amazon basin, secondary organic material dominates the diameter distribution of the submicron particles. How and why is the diameter distribution shifted by pollution? The second objective followed from the first in that, although the diameter distribution is dominated by secondary organic material, the actual source of new particle production remains uncertain (i.e., the number concentration). The second objective was to test the hypothesis that new particles under natural conditions are produced as a result of evaporation of primary particles emitted by fungal spores as well as to investigate any shifts in this mechanism under pollution conditions, e.g., in consequence to the high concentrations of SO2 in the pollution plume. Combined, the number-diameter distribution is the key connection to upscaling to the effects of aerosol

  19. Long-term observation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa, Japan

    Science.gov (United States)

    Handa, Daishi; Somada, Yuka; Ijyu, Moriaki; Azechi, Sotaro; Nakaema, Fumiya; Arakaki, Takemitsu; Tanahara, Akira

    2010-05-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the long-range transported air pollution from Asian continent has gained a special attention in Japan because of increase in photochemical oxidants in relatively remote islands. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) in the bulk aerosols collected at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We will report water-soluble chemical components data of anions, cations and DOC in bulk atmospheric aerosols collected at CHAAMS during August, 2005 to April, 2010. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions. In addition, we calculated background concentration of water-soluble chemical components at Okinawa

  20. Birth, life, and death of a solar coronal plume

    Energy Technology Data Exchange (ETDEWEB)

    Pucci, Stefano; Romoli, Marco [Department of Physics and Astronomy, University of Firenze, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Poletto, Giannina [INAF-Arcetri Astrophysical Observatory, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Sterling, Alphonse C., E-mail: stpucci@arcetri.astro.it [Space Science Office, NASA/MSFC, Huntsville, AL 35812 (United States)

    2014-10-01

    We analyze a solar polar-coronal-hole (CH) plume over its entire ≈40 hr lifetime, using high-resolution Solar Dynamic Observatory Atmospheric Imaging Assembly (AIA) data. We examine (1) the plume's relationship to a bright point (BP) that persists at its base, (2) plume outflows and their possible contribution to the solar wind mass supply, and (3) the physical properties of the plume. We find that the plume started ≈2 hr after the BP first appeared and became undetectable ≈1 hr after the BP disappeared. We detected radially moving radiance variations from both the plume and from interplume regions, corresponding to apparent outflow speeds ranging over ≈(30-300) km s{sup –1} with outflow velocities being higher in the 'cooler' AIA 171 Å channel than in the 'hotter' 193 Å and 211 Å channels, which is inconsistent with wave motions; therefore, we conclude that the observed radiance variations represent material outflows. If they persist into the heliosphere and plumes cover ≈10% of a typical CH area, these flows could account for ≈50% of the solar wind mass. From a differential emission measure analysis of the AIA images, we find that the average electron temperature of the plume remained approximately constant over its lifetime, at T {sub e} ≈ 8.5 × 10{sup 5} K. Its density, however, decreased with the age of the plume, being about a factor of three lower when the plume faded compared to when it was born. We conclude that the plume died due to a density reduction rather than to a temperature decrease.

  1. New particle formation in the fresh flue-gas plume from a coal-fired power plant: effect of flue-gas cleaning

    Science.gov (United States)

    Mylläri, Fanni; Asmi, Eija; Anttila, Tatu; Saukko, Erkka; Vakkari, Ville; Pirjola, Liisa; Hillamo, Risto; Laurila, Tuomas; Häyrinen, Anna; Rautiainen, Jani; Lihavainen, Heikki; O'Connor, Ewan; Niemelä, Ville; Keskinen, Jorma; Dal Maso, Miikka; Rönkkö, Topi

    2016-06-01

    Atmospheric emissions, including particle number and size distribution, from a 726 MWth coal-fired power plant were studied experimentally from a power plant stack and flue-gas plume dispersing in the atmosphere. Experiments were conducted under two different flue-gas cleaning conditions. The results were utilized in a plume dispersion and dilution model taking into account particle formation precursor (H2SO4 resulted from the oxidation of emitted SO2) and assessment related to nucleation rates. The experiments showed that the primary emissions of particles and SO2 were effectively reduced by flue-gas desulfurization and fabric filters, especially the emissions of particles smaller than 200 nm in diameter. Primary pollutant concentrations reached background levels in 200-300 s. However, the atmospheric measurements indicated that new particles larger than 2.5 nm are formed in the flue-gas plume, even in the very early phases of atmospheric ageing. The effective number emission of nucleated particles were several orders of magnitude higher than the primary particle emission. Modelling studies indicate that regardless of continuing dilution of the flue gas, nucleation precursor (H2SO4 from SO2 oxidation) concentrations remain relatively constant. In addition, results indicate that flue-gas nucleation is more efficient than predicted by atmospheric aerosol modelling. In particular, the observation of the new particle formation with rather low flue-gas SO2 concentrations changes the current understanding of the air quality effects of coal combustion. The results can be used to evaluate optimal ways to achieve better air quality, particularly in polluted areas like India and China.

  2. Soil pollution by a pyrite mine spill in Spain: evolution in time

    International Nuclear Information System (INIS)

    Aguilar, J.; Dorronsoro, C.; Fernandez, E.; Fernandez, J.; Garcia, I.; Martin, F.; Simon, M.

    2004-01-01

    Soil pollution was studied after the spill of the Aznalcollar pyrite mine between 1998 and 2001, analyzing As, Zn, Cd, Cu and Pb both in total concentrations as well as in soluble and bioavailable forms. The main remediation measures were: clean-up of the tailings and polluted soils, plus application of amendment materials (liming). The results indicate that, after three years, 50-70% of the acidic soils and 25-30% of the basic soils are still highly polluted in total arsenic. The limit of 0.04 mg kg -1 for water-soluble arsenic is exceeded in 15-20% of all soils. The EDTA-extractable arsenic (bioavailable) exceeds the limit of 2 mg kg -1 only in the acidic sectors. After clean-up, the homogenization of the upper 20-25 cm of the soils appears to be the most recommended measure in the reduction of pollution. - Capsule: Remediation measures carried out after the Aznalcollar pyrite mine spill were effective in the reduction of the pollution, although three years after the accident many areas are still polluted by As

  3. Smoke plumes: Emissions and effects

    Science.gov (United States)

    Susan O' Neill; Shawn Urbanski; Scott Goodrick; Sim Larkin

    2017-01-01

    Smoke can manifest itself as a towering plume rising against the clear blue sky-or as a vast swath of thick haze, with fingers that settle into valleys overnight. It comes in many forms and colors, from fluffy and white to thick and black. Smoke plumes can rise high into the atmosphere and travel great distances across oceans and continents. Or smoke can remain close...

  4. Plume Splitting in a Two-layer Stratified Ambient Fluid

    Science.gov (United States)

    Ma, Yongxing; Flynn, Morris; Sutherland, Bruce

    2017-11-01

    A line-source plume descending into a two-layer stratified ambient fluid in a finite sized tank is studied experimentally. Although the total volume of ambient fluid is fixed, lower- and upper-layer fluids are respectively removed and added at a constant rate mimicking marine outfall through diffusers and natural and hybrid ventilated buildings. The influence of the plume on the ambient depends on the value of λ, defined as the ratio of the plume buoyancy to the buoyancy loss of the plume as it crosses the ambient interface. Similar to classical filling-box experiments, the plume can always reach the bottom of the tank if λ > 1 . By contrast, if λ < 1 , an intermediate layer eventually forms as a result of plume splitting. Eventually all of the plume fluid spreads within the intermediate layer. The starting time, tv, and the ending time, tt, of the transition process measured from experiments correlate with the value of λ. A three-layer ambient fluid is observed after transition, and the mean value of the measured densities of the intermediate layer fluid is well predicted using plume theory. Acknowledgments: Funding for this study was provided by NSERC.

  5. Teaching the Mantle Plumes Debate

    Science.gov (United States)

    Foulger, G. R.

    2010-12-01

    There is an ongoing debate regarding whether or not mantle plumes exist. This debate has highlighted a number of issues regarding how Earth science is currently practised, and how this feeds into approaches toward teaching students. The plume model is an hypothesis, not a proven fact. And yet many researchers assume a priori that plumes exist. This assumption feeds into teaching. That the plume model is unproven, and that many practising researchers are skeptical, may be at best only mentioned in passing to students, with most teachers assuming that plumes are proven to exist. There is typically little emphasis, in particular in undergraduate teaching, that the origin of melting anomalies is currently uncertain and that scientists do not know all the answers. Little encouragement is given to students to become involved in the debate and to consider the pros and cons for themselves. Typically teachers take the approach that “an answer” (or even “the answer”) must be taught to students. Such a pedagogic approach misses an excellent opportunity to allow students to participate in an important ongoing debate in Earth sciences. It also misses the opportunity to illustrate to students several critical aspects regarding correct application of the scientific method. The scientific method involves attempting to disprove hypotheses, not to prove them. A priori assumptions should be kept uppermost in mind and reconsidered at all stages. Multiple working hypotheses should be entertained. The predictions of a hypothesis should be tested, and unpredicted observations taken as weakening the original hypothesis. Hypotheses should not be endlessly adapted to fit unexpected observations. The difficulty with pedagogic treatment of the mantle plumes debate highlights a general uncertainty about how to teach issues in Earth science that are not yet resolved with certainty. It also represents a missed opportunity to let students experience how scientific theories evolve, warts

  6. Analysis of the most important river plumes on the Atlantic and Mediterranean Iberian coast by means of satellite imagery

    Directory of Open Access Journals (Sweden)

    Diego Fernandez Novoa

    2014-06-01

    Full Text Available Rivers discharges cause the formation of buoyant plumes in the adjacent coastal area at their mouths, which are characterized by low-salinity water and controlled by outflow inertia, rotation (Coriolis effects, buoyancy, wind, and tide forcing. The turbid plumes influence the adjacent coastal area, since they control the patterns of nutrients, sediments and/or pollutants of fluvial origin on the coastal ocean and can promote strong physical and chemical changes on seawater. These changes affect the biological characteristics of the area, such as primary production, species composition, abundance and distribution of existing microorganism, which demonstrates its high ecological importance. The characterization of the most important river plumes along the Atlantic Iberian coast and the influence of the main forcing drivers (river discharge, wind and tide on them, was carried out through the analysis of plume mean-state images calculated using water leaving radiance data (nLw555 obtained from the MODIS (Moderate Resolution Imaging Spectroradiometer sensor onboard the Aqua satellite during 2003-2013. Satellite data are downloaded from Ocean Color web site (http://oceancolor.gsfc.nasa.gov. Daily high-resolution L1 files from MODIS-Aqua were processed through SeaDAS software. Composite images, interpolated to a regular pixel grid with an approximate resolution of 500m, were built for different synoptic conditions of river discharge, wind regimes and tide, in order to obtain a representative average plume image of each situation and river for the posterior analysis. Results showed that the river discharge is the main forcing factor in the river plume extension. Wind effect is noticeable under high river discharge and tide is important for the estuarine outflow regimes although with some remarkable similarities and differences between the Atlantic rivers due to their intrinsic characteristics.

  7. Lidar sounding of volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Aiuppa, Alessandro; Angelini, Federico; Borelli, Rodolfo; Del Franco, Mario; Murra, Daniele; Pistilli, Marco; Puiu, Adriana; Santoro, Simone

    2013-10-01

    Accurate knowledge of gas composition in volcanic plumes has high scientific and societal value. On the one hand, it gives information on the geophysical processes taking place inside volcanos; on the other hand, it provides alert on possible eruptions. For this reasons, it has been suggested to monitor volcanic plumes by lidar. In particular, one of the aims of the FP7 ERC project BRIDGE is the measurement of CO2 concentration in volcanic gases by differential absorption lidar. This is a very challenging task due to the harsh environment, the narrowness and weakness of the CO2 absorption lines and the difficulty to procure a suitable laser source. This paper, after a review on remote sensing of volcanic plumes, reports on the current progress of the lidar system.

  8. Plume collimation for laser ablation electrospray ionization mass spectrometry

    Science.gov (United States)

    Vertes, Akos; Stolee, Jessica A.

    2014-09-09

    In various embodiments, a device may generally comprise a capillary having a first end and a second end; a laser to emit energy at a sample in the capillary to ablate the sample and generate an ablation plume in the capillary; an electrospray apparatus to generate an electrospray plume to intercept the ablation plume to produce ions; and a mass spectrometer having an ion transfer inlet to capture the ions. The ablation plume may comprise a collimated ablation plume. The device may comprise a flow cytometer. Methods of making and using the same are also described.

  9. Saharan dust plume charging observed over the UK

    Science.gov (United States)

    Harrison, R. Giles; Nicoll, Keri A.; Marlton, Graeme J.; Ryder, Claire L.; Bennett, Alec J.

    2018-05-01

    A plume of Saharan dust and Iberian smoke was carried across the southern UK on 16th October 2017, entrained into an Atlantic cyclone which had originated as Hurricane Ophelia. The dust plume aloft was widely noticed as it was sufficiently dense to redden the visual appearance of the sun. Time series of backscatter from ceilometers at Reading and Chilbolton show two plumes: one carried upwards to 2.5 km, and another below 800 m into the boundary layer, with a clear slot between. Steady descent of particles at about 50 cm s‑1 continued throughout the morning, and coarse mode particles reached the surface. Plumes containing dust are frequently observed to be strongly charged, often through frictional effects. This plume passed over atmospheric electric field sensors at Bristol, Chilbolton and Reading. Consistent measurements at these three sites indicated negative plume charge. The lower edge plume charge density was (‑8.0 ± 3.3) nC m‑2, which is several times greater than that typical for stratiform water clouds, implying an active in situ charge generation mechanism such as turbulent triboelectrification. A meteorological radiosonde measuring temperature and humidity was launched into the plume at 1412 UTC, specially instrumented with charge and turbulence sensors. This detected charge in the boundary layer and in the upper plume region, and strong turbulent mixing was observed throughout the atmosphere’s lowest 4 km. The clear slot region, through which particles sedimented, was anomalously dry compared with modelled values, with water clouds forming intermittently in the air beneath. Electrical aspects of dust should be included in numerical models, particularly the charge-related effects on cloud microphysical properties, to accurately represent particle behaviour and transport.

  10. Proceedings of plumes, plates and mineralisation symposium: an introduction

    CSIR Research Space (South Africa)

    Hatton, CJ

    1997-12-01

    Full Text Available of plume-theory. Mechanisms of magma formation are identified and plume positions and distances to their surface expression considered. Mantle plumes are considered as a heat and fluid source for the Witwatersrand gold deposits....

  11. Simplified scheme or radioactive plume calculations

    International Nuclear Information System (INIS)

    Gibson, T.A.; Montan, D.N.

    1976-01-01

    A simplified mathematical scheme to estimate external whole-body γ radiation exposure rates from gaseous radioactive plumes was developed for the Rio Blanco Gas Field Nuclear Stimulation Experiment. The method enables one to calculate swiftly, in the field, downwind exposure rates knowing the meteorological conditions and γ radiation exposure rates measured by detectors positioned near the plume source. The method is straightforward and easy to use under field conditions without the help of mini-computers. It is applicable to a wide range of radioactive plume situations. It should be noted that the Rio Blanco experiment was detonated on May 17, 1973, and no seep or release of radioactive material occurred

  12. Hubble Captures Volcanic Eruption Plume From Io

    Science.gov (United States)

    1997-01-01

    The Hubble Space Telescope has snapped a picture of a 400-km-high (250-mile-high) plume of gas and dust from a volcanic eruption on Io, Jupiter's large innermost moon.Io was passing in front of Jupiter when this image was taken by the Wide Field and Planetary Camera 2 in July 1996. The plume appears as an orange patch just off the edge of Io in the eight o'clock position, against the blue background of Jupiter's clouds. Io's volcanic eruptions blasts material hundreds of kilometers into space in giant plumes of gas and dust. In this image, material must have been blown out of the volcano at more than 2,000 mph to form a plume of this size, which is the largest yet seen on Io.Until now, these plumes have only been seen by spacecraft near Jupiter, and their detection from the Earth-orbiting Hubble Space Telescope opens up new opportunities for long-term studies of these remarkable phenomena.The plume seen here is from Pele, one of Io's most powerful volcanos. Pele's eruptions have been seen before. In March 1979, the Voyager 1 spacecraft recorded a 300-km-high eruption cloud from Pele. But the volcano was inactive when the Voyager 2 spacecraft flew by Jupiter in July 1979. This Hubble observation is the first glimpse of a Pele eruption plume since the Voyager expeditions.Io's volcanic plumes are much taller than those produced by terrestrial volcanos because of a combination of factors. The moon's thin atmosphere offers no resistance to the expanding volcanic gases; its weak gravity (one-sixth that of Earth) allows material to climb higher before falling; and its biggest volcanos are more powerful than most of Earth's volcanos.This image is a contrast-enhanced composite of an ultraviolet image (2600 Angstrom wavelength), shown in blue, and a violet image (4100 Angstrom wavelength), shown in orange. The orange color probably occurs because of the absorption and/or scattering of ultraviolet light in the plume. This light from Jupiter passes through the plume and is

  13. Study of atmospheric pollution scavenging. Eighteenth progress report

    Energy Technology Data Exchange (ETDEWEB)

    Semonin, R.G.; Bartlett, J.D.; Bowersox, V.C.; Gatz, D.F.; Naiman, D.Q.; Peden, M.E.; Stahlhut, R.K.; Stensland, G.J.

    1980-07-01

    The analysis of aerosol samples obtained in rural east-central Illinois reveals a seasonal maximum in SO/sub 4/ during May to July and a similar pattern for NH/sub 4/. The annual median SO/sub 4/ is about 1 to 1.5 ..mu..g/m/sup 3/. In contrast to these ions, NO/sub 3/ displays highest values in the cold season. Soil-related species (Ca, K) seem to maximize in relation to farm tillage and harvesting practices. The NO/sub 3/ in recent precipitation samples over the northeast US increased between 1 and 2 times the values observed in the mid-1950's. A case study from SCORE-78 suggests that all ion concentrations analyzed from sequentially collected samples decreased from the onset of rain to a minimum corresponding to the heaviest rain rates. Four groups of elements in 10 event rain samples were identified using factor analysis. The groups include soluble and insoluble crustal elements, soluble pollutant metals and sulfate, and insoluble pollutant metals. Utilizing the factor analysis approach, the St. Louis METROMEX precipitation chemistry data showed that the SO/sub 4/ deposition patterns group consistently with those of other soluble pollutants. Additional factor analysis efforts on the St. Louis rainwater data set revealed that soluble and insoluble concentrations of a given element have different deposition patterns suggesting that scavenging and/or precipitation formation processes dictate the patterns. An approach to managing the vast data base of rain chemistry used in the above studies is described. The software also examines the data for certain aspects of quality assurance. The procedures used to analyze ambient air filter samples are discussed.

  14. CCN concentrations and BC warming influenced by maritime ship emitted aerosol plumes over southern Bay of Bengal.

    Science.gov (United States)

    Ramana, M V; Devi, Archana

    2016-08-02

    Significant quantities of carbon soot aerosols are emitted into pristine parts of the atmosphere by marine shipping. Soot impacts the radiative balance of the Earth-atmosphere system by absorbing solar-terrestrial radiation and modifies the microphysical properties of clouds. Here we examined the impact of black carbon (BC) on net warming during monsoon season over southern Bay-of-Bengal, using surface and satellite measurements of aerosol plumes from shipping. Shipping plumes had enhanced the BC concentrations by a factor of four around the shipping lane and exerted a strong positive influence on net warming. Compiling all the data, we show that BC atmospheric heating rates for relatively-clean and polluted-shipping corridor locations to be 0.06 and 0.16 K/day respectively within the surface layer. Emissions from maritime ships had directly heated the lower troposphere by two-and-half times and created a gradient of around 0.1 K/day on either side of the shipping corridor. Furthermore, we show that ship emitted aerosol plumes were responsible for increase in the concentration of cloud condensation nuclei (CCN) by an order of magnitude that of clean air. The effects seen here may have significant impact on the monsoonal activity over Bay-of-Bengal and implications for climate change mitigation strategies.

  15. Hydrogeological modeling constraints provided by geophysical and geochemical mapping of a chlorinated ethenes plume in northern France

    Science.gov (United States)

    Razafindratsima, Stephen; Guérin, Roger; Bendjoudi, Hocine; de Marsily, Ghislain

    2014-09-01

    A methodological approach is described which combines geophysical and geochemical data to delineate the extent of a chlorinated ethenes plume in northern France; the methodology was used to calibrate a hydrogeological model of the contaminants' migration and degradation. The existence of strong reducing conditions in some parts of the aquifer is first determined by measuring in situ the redox potential and dissolved oxygen, dissolved ferrous iron and chloride concentrations. Electrical resistivity imaging and electromagnetic mapping, using the Slingram method, are then used to determine the shape of the pollutant plume. A decreasing empirical exponential relation between measured chloride concentrations in the water and aquifer electrical resistivity is observed; the resistivity formation factor calculated at a few points also shows a major contribution of chloride concentration in the resistivity of the saturated porous medium. MODFLOW software and MT3D99 first-order parent-daughter chain reaction and the RT3D aerobic-anaerobic model for tetrachloroethene (PCE)/trichloroethene (TCE) dechlorination are finally used for a first attempt at modeling the degradation of the chlorinated ethenes. After calibration, the distribution of the chlorinated ethenes and their degradation products simulated with the model approximately reflects the mean measured values in the observation wells, confirming the data-derived image of the plume.

  16. Exposure of coastal ecosystems to river plume spreading across a near-equatorial continental shelf

    Science.gov (United States)

    Tarya, A.; Hoitink, A. J. F.; Vegt, M. Van der; van Katwijk, M. M.; Hoeksema, B. W.; Bouma, T. J.; Lamers, L. P. M.; Christianen, M. J. A.

    2018-02-01

    The Berau Continental Shelf (BCS) in East Kalimantan, Indonesia, harbours various tropical marine ecosystems, including mangroves, seagrass meadows and coral reefs. These ecosystem are located partly within reach of the Berau River plume, which may affect ecosystem health through exposure to land-derived sediments, nutrients and pollutants carried by the plume. This study aims (1) to assess the exposure risk of the BCS coastal ecosystems to river plume water, measured as exposure time to three different salinity levels, (2) to identify the relationships between these salinity levels and the abundance and diversity of coral and seagrass ecosystems, and (3) to determine a suitable indicator for the impacts of salinity on coral reef and seagrass health. We analysed hydrodynamic models, classified salinity levels, and quantified the correlations between the salinity model parameters and ecological metrics for the BCS systems. An Empirical Orthogonal Functions (EOF) analysis revealed three modes of river plume dispersal patterns, which strongly reflect monsoon seasonality. The first mode, explaining 39% of the variability, was associated with the southward movement of the plume due to northerly winds, while the second and third modes (explaining 29% and 26% of the variability, respectively) were associated with the northeastward migration of the plume related to southwesterly and southerly winds. Exposure to low salinity showed higher correlations with biological indicators than mean salinity, indicating that low salinity is a more suitable indicator for coastal ecosystem health. Significant correlations (R2) were found between exposure time to low salinity (days with salinity values below 25 PSU) with coral cover, coral species richness, seagrass cover, the number of seagrass species, seagrass leaf phosphorus, nitrogen, C:N ratio and iron content. By comparing the correlation coefficients and the slopes of the regression lines, our study suggests that coral reefs are

  17. Biosurfactant-enhanced bioremediation of hydrophobic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Makkar, R.S. [Inst. of Microbial Technology, Chandigarh (India)

    2010-01-15

    Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and - philic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures-lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs), crude on sludge, and pesticides call be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released into the environment as a result of oil spillage and by-products of coal treatment processes. The low water solubility of these compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential hioremediation applications.

  18. An integral model of plume rise from high explosive detonations

    International Nuclear Information System (INIS)

    Boughton, B.A.; De Laurentis, J.M.

    1987-01-01

    A numerical model has been developed which provides a complete description of the time evolution of both the physical and thermodynamic properties of the cloud formed when a high explosive is detonated. This simulation employs the integral technique. The model equations are derived by integrating the three-dimensional conservation equations of mass, momentum and energy over the plume cross section. Assumptions are made regarding (a) plume symmetry; (b) the shape of profiles of velocity, temperature, etc. across the plume; and (c) the methodology for simulating entrainment and the effects of the crossflow induced pressure drag force on the plume. With these assumptions, the integral equations can be reduced to a set of ordinary differential equations on the plume centerline variables. Only the macroscopic plume characteristics, e.g., plume radius, centerline height, temperature and density, are predicted; details of the plume intrastructure are ignored. The model explicitly takes into account existing meteorology and has been expanded to consider the alterations in plume behavior which occur when aqueous foam is used as a dispersal mitigating material. The simulation was tested by comparison with field measurements of cloud top height and diameter. Predictions were within 25% of field observations over a wide range of explosive yield and atmospheric stability

  19. The controversy over plumes: Who is actually right?

    Science.gov (United States)

    Puchkov, V. N.

    2009-01-01

    The current state of the theory of mantle plumes and its relation to classic plate tectonics show that the “plume” line of geodynamic research is in a period of serious crisis. The number of publications criticizing this concept is steadily increasing. The initial suggestions of plumes’ advocates are disputed, and not without grounds. Questions have been raised as to whether all plumes are derived from the mantle-core interface; whether they all have a wide head and a narrow tail; whether they are always accompanied by uplifting of the Earth’s surface; and whether they can be reliably identified by geochemical signatures, e.g., by the helium-isotope ratio. Rather convincing evidence indicates that plumes cannot be regarded as a strictly fixed reference frame for moving lithospheric plates. More generally, the very existence of plumes has become the subject of debate. Alternative ideas contend that all plumes, or hot spots, are directly related to plate-tectonic mechanisms and appear as a result of shallow tectonic stress, subsequent decompression, and melting of the mantle enriched in basaltic material. Attempts have been made to explain the regular variation in age of volcanoes in ocean ridges by the crack propagation mechanism or by drift of melted segregations of enriched mantle in a nearly horizontal asthenospheric flow. In the author’s opinion, the crisis may be overcome by returning to the beginnings of the plume concept and by providing an adequate specification of plume attributes. Only mantle flows with sources situated below the asthenosphere should be referred to as plumes. These flows are not directly related to such plate-tectonic mechanisms as passive rifting and decompression melting in the upper asthenosphere and are marked by time-progressive volcanic chains; their subasthenospheric roots are detected in seismic tomographic images. Such plumes are mostly located at the margins of superswells, regions of attenuation of seismic waves at the

  20. Interdisciplinary study of atmospheric processes and constituents of the mid-Atlantic coastal region.. [air pollution control studies in Virginia

    Science.gov (United States)

    Kindle, E. C.; Bandy, E. C.; Copeland, G.; Blais, R.; Levy, G.; Sonenshine, D.

    1975-01-01

    Past research projects for the year 1974-1975 are listed along with future research programs in the area of air pollution control, remote sensor analysis of smoke plumes, the biosphere component, and field experiments. A detailed budget analysis is presented. Attachments are included on the following topics: mapping forest vegetation with ERTS-1 MSS data and automatic data processing techniques, and use of LARS system for the quantitative determination of smoke plume lateral diffusion coefficients from ERTS images of Virginia.

  1. On the relative motions of long-lived Pacific mantle plumes.

    Science.gov (United States)

    Konrad, Kevin; Koppers, Anthony A P; Steinberger, Bernhard; Finlayson, Valerie A; Konter, Jasper G; Jackson, Matthew G

    2018-02-27

    Mantle plumes upwelling beneath moving tectonic plates generate age-progressive chains of volcanos (hotspot chains) used to reconstruct plate motion. However, these hotspots appear to move relative to each other, implying that plumes are not laterally fixed. The lack of age constraints on long-lived, coeval hotspot chains hinders attempts to reconstruct plate motion and quantify relative plume motions. Here we provide 40 Ar/ 39 Ar ages for a newly identified long-lived mantle plume, which formed the Rurutu hotspot chain. By comparing the inter-hotspot distances between three Pacific hotspots, we show that Hawaii is unique in its strong, rapid southward motion from 60 to 50 Myrs ago, consistent with paleomagnetic observations. Conversely, the Rurutu and Louisville chains show little motion. Current geodynamic plume motion models can reproduce the first-order motions for these plumes, but only when each plume is rooted in the lowermost mantle.

  2. Volcanic eruption plumes on Io

    International Nuclear Information System (INIS)

    Strom, R.G.; Terrile, R.J.; Masursky, H.; Hansen, C.

    1979-01-01

    The detection of an umbrella-shaped plume extending about 280 km above the bright limb of Io was one of the most important discoveries made during the Voyager 1 encounter with the jovian system. This discovery proves that Io is volcanically active at present, and the number and magnitude of these eruptions indicate that Io is the most volcanically active body so far discovered in the Solar System. Preliminary analyses of these eruptive plumes are presented. (U.K.)

  3. Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations

    Directory of Open Access Journals (Sweden)

    F. Darrouzet

    2006-07-01

    Full Text Available Plasmaspheric plumes have been routinely observed by CLUSTER and IMAGE. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles have been derived from the electron plasma frequency identified by the WHISPER sounder supplemented, in-between soundings, by relative variations of the spacecraft potential measured by the electric field instrument EFW; ion velocity is also measured onboard these satellites. The EUV imager onboard the IMAGE spacecraft provides global images of the plasmasphere with a spatial resolution of 0.1 RE every 10 min; such images acquired near apogee from high above the pole show the geometry of plasmaspheric plumes, their evolution and motion. We present coordinated observations of three plume events and compare CLUSTER in-situ data with global images of the plasmasphere obtained by IMAGE. In particular, we study the geometry and the orientation of plasmaspheric plumes by using four-point analysis methods. We compare several aspects of plume motion as determined by different methods: (i inner and outer plume boundary velocity calculated from time delays of this boundary as observed by the wave experiment WHISPER on the four spacecraft, (ii drift velocity measured by the electron drift instrument EDI onboard CLUSTER and (iii global velocity determined from successive EUV images. These different techniques consistently indicate that plasmaspheric plumes rotate around the Earth, with their foot fully co-rotating, but with their tip rotating slower and moving farther out.

  4. River plume patterns and dynamics within the Southern California Bight

    Science.gov (United States)

    Warrick, J.A.; DiGiacomo, P.M.; Weisberg, S.B.; Nezlin, N.P.; Mengel, M.; Jones, B.H.; Ohlmann, J.C.; Washburn, L.; Terrill, E.J.; Farnsworth, K.L.

    2007-01-01

    Stormwater river plumes are important vectors of marine contaminants and pathogens in the Southern California Bight. Here we report the results of a multi-institution investigation of the river plumes across eight major river systems of southern California. We use in situ water samples from multi-day cruises in combination with MODIS satellite remote sensing, buoy meteorological observations, drifters, and HF radar current measurements to evaluate the dispersal patterns and dynamics of the freshwater plumes. River discharge was exceptionally episodic, and the majority of storm discharge occurred in a few hours. The combined plume observing techniques revealed that plumes commonly detach from the coast and turn to the left, which is the opposite direction of Coriolis influence. Although initial offshore velocity of the buoyant plumes was ∼50 cm/s and was influenced by river discharge inertia (i.e., the direct momentum of the river flux) and buoyancy, subsequent advection of the plumes was largely observed in an alongshore direction and dominated by local winds. Due to the multiple day upwelling wind conditions that commonly follow discharge events, plumes were observed to flow from their respective river mouths to down-coast waters at rates of 20–40 km/d. Lastly, we note that suspended-sediment concentration and beam-attenuation were poorly correlated with plume salinity across and within the sampled plumes (mean r2=0.12 and 0.25, respectively), while colored dissolved organic matter (CDOM) fluorescence was well correlated (mean r2=0.56), suggesting that CDOM may serve as a good tracer of the discharged freshwater in subsequent remote sensing and monitoring efforts of plumes.

  5. Using satellite imagery for qualitative evaluation of plume transport in modeling the effects of the Kuwait oil fire smoke plumes

    International Nuclear Information System (INIS)

    Bass, A.; Janota, P.

    1992-01-01

    To forecast the behavior of the Kuwait oil fire smoke plumes and their possible acute or chronic health effects over the Arabian Gulf region, TASC created a comprehensive health and environmental impacts modeling system. A specially-adapted Lagrangian puff transport model was used to create (a) short-term (multiday) forecasts of plume transport and ground-level concentrations of soot and SO 2 ; and (b) long-term (seasonal and longer) estimates of average surface concentrations and depositions. EPA-approved algorithms were used to transform exposures to SO 2 and soot (as PAH/BaP) into morbidity, mortality and crop damage risks. Absent any ground truth, satellite imagery from the NOAA Polar Orbiter and the ESA Geostationary Meteosat offered the only opportunity for timely qualitative evaluation of the long-range plume transport and diffusion predictions. This paper shows the use of actual satellite images (including animated loops of hourly Meteosat images) to evaluate plume forecasts in near-real-time, and to sanity-check the meso- and long-range plume transport projections for the long-term estimates. Example modeled concentrations, depositions and health effects are shown

  6. Field experimental observations of highly graded sediment plumes

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina; Jimenez, Carlos

    2015-01-01

    A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes......-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages...... are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model....

  7. Volcanic Plume Measurements with UAV (Invited)

    Science.gov (United States)

    Shinohara, H.; Kaneko, T.; Ohminato, T.

    2013-12-01

    Volatiles in magmas are the driving force of volcanic eruptions and quantification of volcanic gas flux and composition is important for the volcano monitoring. Recently we developed a portable gas sensor system (Multi-GAS) to quantify the volcanic gas composition by measuring volcanic plumes and obtained volcanic gas compositions of actively degassing volcanoes. As the Multi-GAS measures variation of volcanic gas component concentrations in the pumped air (volcanic plume), we need to bring the apparatus into the volcanic plume. Commonly the observer brings the apparatus to the summit crater by himself but such measurements are not possible under conditions of high risk of volcanic eruption or difficulty to approach the summit due to topography etc. In order to overcome these difficulties, volcanic plume measurements were performed by using manned and unmanned aerial vehicles. The volcanic plume measurements by manned aerial vehicles, however, are also not possible under high risk of eruption. The strict regulation against the modification of the aircraft, such as installing sampling pipes, also causes difficulty due to the high cost. Application of the UAVs for the volcanic plume measurements has a big advantage to avoid these problems. The Multi-GAS consists of IR-CO2 and H2O gas analyzer, SO2-H2O chemical sensors and H2 semiconductor sensor and the total weight ranges 3-6 kg including batteries. The necessary conditions of the UAV for the volcanic plumes measurements with the Multi-GAS are the payloads larger than 3 kg, maximum altitude larger than the plume height and installation of the sampling pipe without contamination of the exhaust gases, as the exhaust gases contain high concentrations of H2, SO2 and CO2. Up to now, three different types of UAVs were applied for the measurements; Kite-plane (Sky Remote) at Miyakejima operated by JMA, Unmanned airplane (Air Photo Service) at Shinomoedake, Kirishima volcano, and Unmanned helicopter (Yamaha) at Sakurajima

  8. Organic contaminants in thermal plume resident brown trout

    International Nuclear Information System (INIS)

    Romberg, G.P.; Bourne, S.

    1978-01-01

    A pilot study was conducted to identify possible contaminants accumulated by thermal plume-resident fish in Lake Michigan. Brown trout were maintained in tanks receiving intake and discharge (less than or equal to 21 0 C) water from a power plant and were fed a diet of frozen alewife. Fish were sampled over a period of 127 days in order to estimate uptake rates and equilibrium levels for toxic organic and inorganic materials occurring in Lake Michigan fish and water. Experimental fish and natural samples were analyzed to determine the distribution of contaminants in various tissues and the corresponding pollutant levels in similar size brown trout from Lake Michigan. The quantitative analyses for the major organic contaminants are summarized. Without exception, the pyloric caecum of brown trout contained the highest concentration of lipids, PCB's, and chlorinated pesticides. Gill and kidney samples contained lower concentrations of contaminants than the caecum, while liver and muscle values were lowest

  9. Calculation of doses received while crossing a plume of radioactive material

    International Nuclear Information System (INIS)

    Scherpelz, R.I.; Desrosiers, A.E.

    1981-04-01

    A method has been developed for determining the dose received by a person while crossing a plume of radioactive material. The method uses a Gaussian plume model to arrive at a dose rate on the plume centerline at the position of the plume crossing. This dose rate may be due to any external or internal dose pathway. An algebraic formula can then be used to convert the plume centerline dose rate to a total dose integrated over the total time of plume crossing. Correction factors are presented for dose pathways in which the dose rate is not normally distributed about the plume centerline. The method is illustrated by a study done at the Pacific Northwest Laboratory, and results of this study are presented

  10. Rapid intrinsic biodegradation of benzene, toluene, and xylenes at the boundary of a gasoline-contaminated plume under natural attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Takahata, Yoh; Hoaki, Toshihiro [Taisei Corp., Yokohama (Japan). Civil Engineering Research Inst.; Kasai, Yuki; Watanabe, Kazuya [Marine Biotechnology Institute, Kamaishi (Japan)

    2006-12-15

    A groundwater plume contaminated with gasoline constituents [mainly benzene, toluene, and xylenes (BTX)] had been treated by pumping and aeration for approximately 10 years, and the treatment strategy was recently changed to monitored natural attenuation (MNA). To gain information on the feasibility of using MNA to control the spread of BTX, chemical and microbiological parameters in groundwater samples obtained inside and outside the contaminated plume were measured over the course of 73 weeks. The depletion of electron acceptors (i.e., dissolved oxygen, nitrate, and sulfate) and increase of soluble iron were observed in the contaminated zone. Laboratory incubation tests revealed that groundwater obtained immediately outside the contaminated zone (the boundary zone) exhibited much higher potential for BTX degradation than those in the contaminated zone and in uncontaminated background zones. The boundary zone was a former contaminated area where BTX were no longer detected. Denaturing gradient gel electrophoresis (DGGE) analysis of polymerase chain reaction (PCR)-amplified bacterial 16S rRNA gene fragments revealed that DGGE profiles for groundwater samples obtained from the contaminated zone were clustered together and distinct from those from uncontaminated zones. In addition, unique bacterial rRNA types were observed in the boundary zone. These results indicate that the boundary zone in the contaminant plumes served as a natural barrier for preventing the BTX contamination from spreading out. (orig.)

  11. Mathematical models for atmospheric pollutants. Appendix A. Elements of meteorology. Final report

    International Nuclear Information System (INIS)

    Drake, R.L.; Laulainen, N.S.

    1979-08-01

    The meteorological elements that are important in the transport and fate of airborne pollutants are summarized. The summary consists of descriptions of the thermal, water, kinematic and dynamic structures of the atmosphere, the time and space scale classifications of atmospheric motions, and modifications of pollutant plumes as they pass over nonhomogeneous surface conditions and complex terrain. The discussions consider the atmospheric thermal layers and their stability, formation of clouds and the production of rain and snow, the movement of air masses and weather fronts, the horizontal winds in the planetary boundary layer, and wind profiles over transition zones and complex terrain

  12. Argonne National Laboratory's thermal plume measurements: instruments and techniques

    International Nuclear Information System (INIS)

    Van Loon, L.S.; Frigo, A.A.; Paddock, R.A.

    1977-12-01

    Instrumentation and techniques were developed at Argonne National Laboratory for measuring the three-dimensional temperature structure of thermal plumes from power plants, along with the limnological, meteorological, and plant operating conditions affecting their behavior. The equipment and procedures were designed to provide field data for use in evaluating predictive models that describe thermal plume behavior, and over 100 sets of these data have been collected. The instrument systems and techniques employed in a typical thermal discharge survey are highly integrated. Continuous monitoring of ambient and plant conditions is coupled with plume mapping from a moving survey boat. The instantaneous location of the boat together with subsurface temperature measurements from a towed thermistor chain provide a quasisynoptic view of the plume structure. Real-time, onboard display of the boat path and vertical temperatures supply feedback to investigators for determining the extent and spatial resolution of measurements required. The unique design, reliability, accuracy, calibration, and historical development of the components of these integrated systems are described. Survey system interfaces with data handling and processing techniques are also explained. Special supportive studies to investigate plume dynamics, values of eddy diffusivities, time-temperature histories of water parcels in thermal plumes, and rapid changes in plume shape are also described along with instrumentation used

  13. Experiments on Plume Spreading by Engineered Injection and Extraction

    Science.gov (United States)

    Mays, D. C.; Jones, M.; Tigera, R. G.; Neupauer, R.

    2014-12-01

    The notion that groundwater remediation is transport-limited emphasizes the coupling between physical (i.e., hydrodynamic), geochemical, and microbiological processes in the subsurface. Here we leverage this coupling to promote groundwater remediation using the approach of engineered injection and extraction. In this approach, inspired by the literature on chaotic advection, uncontaminated groundwater is injected and extracted through a manifold of wells surrounding the contaminated plume. The potential of this approach lies in its ability to actively manipulate the velocity field near the contaminated plume, generating plume spreading above and beyond that resulting from aquifer heterogeneity. Plume spreading, in turn, promotes mixing and reaction by chemical and biological processes. Simulations have predicted that engineered injection and extraction generates (1) chaotic advection whose characteristics depend on aquifer heterogeneity, and (2) faster rates and increased extent of groundwater remediation. This presentation focuses on a complimentary effort to experimentally demonstrate these predictions experimentally. In preparation for future work using refractive index matched (RIM) porous media, the experiments reported here use a Hele-Shaw apparatus containing silicone oil. Engineered injection and extraction is used to manipulate the geometry of an initially circular plume of black pigment, and photographs record the plume geometry after each step of injection of extraction. Image analysis, using complimentary Eulerian and Lagrangian approaches, reveals the thickness and variability of the dispersion zone surrounding the deformed plume of black pigment. The size, shape, and evolution of this dispersion zone provides insight into the interplay between engineered injection and extraction, which generates plume structure, and dispersion (here Taylor dispersion), which destroys plume structure. These experiments lay the groundwork for application of engineered

  14. A study of the physical factors affecting air pollution dispersion in Helwan

    International Nuclear Information System (INIS)

    Megahed, A.A.

    1992-01-01

    Air pollution is considered as one of the most important environmental problems facing the humanity. Cement industry, usually, is responsible for building high levels of pollutants. The present research focused on the study of air pollution control of cement industry using mathematical modeling. A mathematical dispersion model was developed based on Gaussian distribution where the dispersion parameters increase with increasing atmospheric turbulence. The Gaussian equation takes in consideration the effect of emission rates. stack height, buoyant plume rise, weather and meteorological parameters. The model was tested for different stack heights, wind speeds. And atmospheric stability classes. Maximum ground level concentration of cement pollutants were measured in different locations of Helwan, south Cairo around the cement factories. Analysis of results shows that the ground level of pollutants concentrations are inversely proportional to wind speed and atmospheric stability classes. Stack height also affects the behaviour of deposition of cement particulates. The model results show satisfactory agreement with the measured concentrations. 6 figs

  15. Intrinsic bioremediation of a BTEX and MTBE plume under mixed aerobic/denitrifying conditions

    International Nuclear Information System (INIS)

    Borden, R.C.; Daniel, R.A.

    1995-01-01

    A shallow Coastal Plain aquifer in rural Sampson Country, North Carolina, has been contaminated with petroleum hydrocarbon from a leaking underground storage tank containing gasoline.An extensive field characterization has been performed to define the horizontal and vertical distribution of soluble gasoline components and indicator parameters. A plume of dissolved methyl tert-butyl ether (MTBE) and the aromatic hydrocarbons benzene, toluene, ethylbenzene, and xylene isomers (BTEX) is present in the aquifer and has migrated over 600 ft from the source area. Background dissolved oxygen concentrations range from 7 to 8 mg/L, and nitrate concentrations range from 5 to 22 mg/L as N due to extensive fertilization of fields surrounding the spill. In the center of the BTEX plume, oxygen concentrations decline to less than 1 mg/L while nitrate concentrations remain high. The total mass flux of MTBE and all BTEX components decline with distance downgradient relative to a conservative tracer (chloride). At the source, the total BTEX concentration exceeds 75 mg/L while 130 ft downgradient, total BTEX concentrations are less than 4.9 mg/L, a 15-fold reduction. Toluene and ethylbenzene decline most rapidly followed by m-p-xylene, o-xylene and finally benzene. Biodegradation of TEX appears to be enhanced by the excess nitrate present in the aquifer while benzene biodegradation appears to be due to strictly aerobic processes

  16. Io with Loki Plume on Bright Limb

    Science.gov (United States)

    1990-01-01

    Voyager 1 image of Io showing active plume of Loki on limb. Heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers (340,000 miles).

  17. Laser-generated plasma plume expansion: Combined continuous-microscopic modeling

    Science.gov (United States)

    Itina, Tatiana E.; Hermann, Jörg; Delaporte, Philippe; Sentis, Marc

    2002-12-01

    The physical phenomena involved in the interaction of a laser-generated plasma plume with a background gas are studied numerically. A three-dimensional combined model is developed to describe the plasma plume formation and its expansion in vacuum or into a background gas. The proposed approach takes advantages of both continuous and microscopic descriptions. The simulation technique is suitable for the simulation of high-rate laser ablation for a wide range of background pressure. The model takes into account the mass diffusion and the energy exchange between the ablated and background species, as well as the collective motion of the ablated species and the background-gas particles. The developed approach is used to investigate the influence of the background gas on the expansion dynamics of the plume obtained during the laser ablation of aluminum. At moderate pressures, both plume and gas compressions are weak and the process is mainly governed by the diffusive mixing. At higher pressures, the interaction is determined by the plume-gas pressure interplay, the plume front is strongly compressed, and its center exhibits oscillations. In this case, the snowplough effect takes place, leading to the formation of a compressed gas layer in front of the plume. The background pressure needed for the beginning of the snowplough effect is determined from the plume and gas density profiles obtained at various pressures. Simulation results are compared with experimentally measured density distributions. It is shown that the calculations suggest localized formation of molecules during reactive laser ablation.

  18. Laser-generated plasma plume expansion: Combined continuous-microscopic modeling

    International Nuclear Information System (INIS)

    Itina, Tatiana E.; Hermann, Joerg; Delaporte, Philippe; Sentis, Marc

    2002-01-01

    The physical phenomena involved in the interaction of a laser-generated plasma plume with a background gas are studied numerically. A three-dimensional combined model is developed to describe the plasma plume formation and its expansion in vacuum or into a background gas. The proposed approach takes advantages of both continuous and microscopic descriptions. The simulation technique is suitable for the simulation of high-rate laser ablation for a wide range of background pressure. The model takes into account the mass diffusion and the energy exchange between the ablated and background species, as well as the collective motion of the ablated species and the background-gas particles. The developed approach is used to investigate the influence of the background gas on the expansion dynamics of the plume obtained during the laser ablation of aluminum. At moderate pressures, both plume and gas compressions are weak and the process is mainly governed by the diffusive mixing. At higher pressures, the interaction is determined by the plume-gas pressure interplay, the plume front is strongly compressed, and its center exhibits oscillations. In this case, the snowplough effect takes place, leading to the formation of a compressed gas layer in front of the plume. The background pressure needed for the beginning of the snowplough effect is determined from the plume and gas density profiles obtained at various pressures. Simulation results are compared with experimentally measured density distributions. It is shown that the calculations suggest localized formation of molecules during reactive laser ablation

  19. Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology

    Science.gov (United States)

    Stevens, R. G.; Pierce, J. R.; Brock, C. A.; Reed, M. K.; Crawford, J. H.; Holloway, J. S.; Ryerson, T. B.; Huey, L. G.; Nowak, J. B.

    2012-01-01

    New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulfur sources may be an important source of particles in the atmosphere. It remains unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are 10s of kilometers and larger. The predictive power of these models is thus limited by the resultant uncertainties in aerosol size distributions. In this paper, we focus on sub-grid sulfate aerosol processes within coal-fired power plant plumes: the sub-grid oxidation of SO2 with condensation of H2SO4 onto newly-formed and pre-existing particles. We have developed a modeling framework with aerosol microphysics in the System for Atmospheric Modelling (SAM), a Large-Eddy Simulation/Cloud-Resolving Model (LES/CRM). The model is evaluated against aircraft observations of new-particle formation in two different power-plant plumes and reproduces the major features of the observations. We show how the downwind plume aerosols can be greatly modified by both meteorological and background aerosol conditions. In general, new-particle formation and growth is greatly reduced during polluted conditions due to the large pre-existing aerosol surface area for H2SO4 condensation and particle coagulation. The new-particle formation and growth rates are also a strong function of the amount of sunlight and NOx since both control OH concentrations. The results of this study highlight the importance for improved sub-grid particle formation schemes in regional and global aerosol models.

  20. Field experimental observations of highly graded sediment plumes.

    Science.gov (United States)

    Jensen, Jacob Hjelmager; Saremi, Sina; Jimenez, Carlos; Hadjioannou, Louis

    2015-06-15

    A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes, gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in the water column, and facing the plume at different angles. The processes were captured using GoPro-Hero-series cameras. The high-quality underwater footage from near-surface, mid-depth and near-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Enhanced natural attenuation of heterocyclic hydrocarbons: biodegradation under anaerobic conditions and in the presence of H2O2

    International Nuclear Information System (INIS)

    Sagner, A.; Tiehm, A.

    2005-01-01

    Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen (NSO-HET) are highly mobile due to their high water solubility and low anaerobic degradation rates. In addition some of them are highly toxic and also carcinogenic. However, this class of pollutants is not included in standard risk assessment protocols. In our study, NSO-HET were analyzed in tar oil polluted groundwater plumes originating from (i) a small landfill and (ii) an abandoned manufactured gas plant site. A similar composition of the NSO-HET benzofuran, dibenzo-furan, benzo-thiophene, dibenzo-thiophene, quinoline, and carbazole was found at the two sites. In the polluted groundwater plume, the two ring NSO-HET decreased more rapidly as compared to the three ring NSO-HET. In anaerobic microcosm studies, only benzofuran was degraded under sulfate reducing conditions. In the presence of Fe(III) or nitrate, benzo-thiophene and dibenzo-thiophene were degraded within 400 days. Under aerobic conditions, the degradation of all NSO-HET was observed. In conclusion, the addition of oxygen or hydrogen peroxide is a suitable measure to stimulate biodegradation of hetero-aromatic compounds. (authors)

  2. Plume rise from stacks with scrubbers: a state-of-the-art review

    International Nuclear Information System (INIS)

    Schatzmann, M.; Policastro, A.J.

    1984-01-01

    The state of the art of predicting plume rise from stacks with scrubbers is evaluated critically. The significant moisture content of the scrubbed plume upon exit leads to important thermodynamic effects during plume rise that are unaccounted for in the usual dry plume rise theories. For example, under conditionally unstable atmospheres, a wet scrubbed plume treated as completely dry acts as if the atmosphere were stable, whereas in reality the scrubbed plume behaves instead as if the atmosphere were unstable. Even the use of moist plume models developed for application to cooling tower plume rise is not valid since these models 1) employ the Boussinesq approximation, 2) use a number of additional simplifying approximations that require small exit temperature differences between tower exit and ambient temperatures, and 3) are not calibrated to stack data

  3. Diagnostics of laser ablated plasma plumes

    DEFF Research Database (Denmark)

    Amoruso, S.; Toftmann, B.; Schou, Jørgen

    2004-01-01

    The effect of an ambient gas on the expansion dynamics of laser ablated plasmas has been studied for two systems by exploiting different diagnostic techniques. First, the dynamics of a MgB2 laser produced plasma plume in an Ar atmosphere has been investigated by space-and time-resolved optical...... of the laser ablated plasma plume propagation in a background gas. (C) 2003 Elsevier B.V All rights reserved....

  4. Mantle plumes on Venus revisited

    Science.gov (United States)

    Kiefer, Walter S.

    1992-01-01

    The Equatorial Highlands of Venus consist of a series of quasicircular regions of high topography, rising up to about 5 km above the mean planetary radius. These highlands are strongly correlated with positive geoid anomalies, with a peak amplitude of 120 m at Atla Regio. Shield volcanism is observed at Beta, Eistla, Bell, and Atla Regiones and in the Hathor Mons-Innini Mons-Ushas Mons region of the southern hemisphere. Volcanos have also been mapped in Phoebe Regio and flood volcanism is observed in Ovda and Thetis Regiones. Extensional tectonism is also observed in Ovda and Thetis Regiones. Extensional tectonism is also observed in many of these regions. It is now widely accepted that at least Beta, Atla, Eistla, and Bell Regiones are the surface expressions of hot, rising mantel plumes. Upwelling plumes are consistent with both the volcanism and the extensional tectonism observed in these regions. The geoid anomalies and topography of these four regions show considerable variation. Peak geoid anomalies exceed 90 m at Beta and Atla, but are only 40 m at Eistla and 24 m at Bell. Similarly, the peak topography is greater at Beta and Atla than at Eistla and Bell. Such a range of values is not surprising because terrestrial hotspot swells also have a side range of geoid anomalies and topographic uplifts. Kiefer and Hager used cylindrical axisymmetric, steady-state convection calculations to show that mantle plumes can quantitatively account for both the amplitude and the shape of the long-wavelength geoid and topography at Beta and Atla. In these models, most of the topography of these highlands is due to uplift by the vertical normal stress associated with the rising plume. Additional topography may also be present due to crustal thickening by volcanism and crustal thinning by rifting. Smrekar and Phillips have also considered the geoid and topography of plumes on Venus, but they restricted themselves to considering only the geoid-topography ratio and did not

  5. Bio-Physical Coupling of Seabirds and Prey with a Dynamic River Plume

    Science.gov (United States)

    Phillips, E. M.; Horne, J. K.; Zamon, J. E.; Adams, J.

    2016-02-01

    Freshwater plumes and plume density fronts are important regions of bio-physical coupling. On the west coast of North America, discharge from the Columbia River into the northern California Current creates a large, dynamic plume and multiple plume fronts. These nutrient-rich, productive waters fuel primary and secondary production, supporting a wide variety of small pelagic prey fish, large populations of Pacific salmon, seabirds, and marine mammals. To determine the influence of the Columbia River plume on marine predators, we analyzed at-sea seabird counts, in situ environmental data, surface trawl densities of prey fish, and acoustic backscatter measurements collected from research vessels in May and June 2010-2012. Concurrent distribution patterns of satellite-tagged sooty shearwaters (Puffinus griseus) and common murres (Uria aalge) were compared with seabird counts from ship surveys. To evaluate plume use by satellite-tagged birds, daily surface salinity values from SELFE hindcast models were extracted at each tag location. Both seabird species occurred in plume waters disproportionate to the total surveyed area, concentrating in the river plume when river flow and plume volume decreased. Murres were consistently within 20 km of the geographic mean center of the river plume. In contrast, shearwaters consistently occurred 100 km to the north of the plume center, where high densities of prey fish occur. Although acoustically detected prey also occurred in greater densities within the plume when volume decreased, surface catches of prey in the plume did not vary with changing plume conditions. Geographic indices of colocation (GIC) were low between murres and prey species caught in surface trawls, whereas GICs were >0.5 between shearwaters and prey species including squid (Loligo opalescens), juvenile Chinook salmon (Oncorhynchus tshawytscha), and coho (O. kisutch) salmon. We conclude that the river plume and associated fronts are identifiable, predictable, and

  6. ALOFT-PC a smoke plume trajectory model for personal computers

    International Nuclear Information System (INIS)

    Walton, W.D.; McGrattan, K.B.; Mullin, J.V.

    1996-01-01

    A computer model, named ALOFT-PC, was developed for use during in-situ burning of oil spills to predict smoke plume trajectory. The downwind distribution of smoke particulate is a complex function of fire parameters, meteorological conditions, and topographic features. Experimental burns have shown that the downwind distribution of smoke is not Gaussian and simple smoke plume models do not capture the observed plume features. ALOFT-PC consists of the Navier-Stokes equations using an eddy viscosity over a uniform grid that spans the smoke plume and its surroundings. The model inputs are wind speed and variability, atmospheric temperature profile, and fire parameters and the output is the average of the plume. 7 refs., 3 tabs

  7. Loire and Gironde turbid plumes: Characterization and influence on thermohaline properties

    Science.gov (United States)

    Costoya, X.; Fernández-Nóvoa, D.; deCastro, M.; Gómez-Gesteira, M.

    2017-12-01

    Knowledge and predictability of turbid river plumes is of great importance because they modulate the properties of the seawater adjacent to river mouths. The Loire and Gironde Rivers form the most important plumes in the Bay of Biscay, as they provide > 75% of total runoff. The development of the turbid plume under the influence of its main drivers was analyzed using Moderate Resolution Imaging Spectroradiometer satellite data from the period 2003-2015. River discharge was found to be the main driver, followed by wind, which also had an important effect in modulating the turbid plume during periods of high river discharge. Seaward and upwelling favorable winds enhanced the dispersion of plumes on seawater, whereas landward and downwelling favorable winds limited mixing with the adjacent ocean water. The maximum extension of the turbid plume was reached under landward winds. In addition, the spatio-temporal evolution of the East Atlantic pattern and the North Atlantic Oscillation was observed to affect the dynamics of plumes: positive values of both indices favored a greater extension of the plume. Thermohaline properties differed inside and outside the area affected by both rivers. In particular, these rivers maintain winter stratification inside the turbid plume, which results in a different warming ratio when compared with the adjacent ocean.

  8. A study of atmospheric diffusion from the LANDSAT imagery. [pollution transport over the ocean

    Science.gov (United States)

    Dejesusparada, N. (Principal Investigator); Viswanadham, Y.; Torsani, J. A.

    1981-01-01

    LANDSAT multispectral scanner data of the smoke plumes which originated in eastern Cabo Frio, Brazil and crossed over into the Atlantic Ocean, are analyzed to illustrate how high resolution LANDSAT imagery can aid meteorologists in evaluating specific air pollution events. The eleven LANDSAT images selected are for different months and years. The results show that diffusion is governed primarily by water and air temperature differences. With colder water, low level air is very stable and the vertical diffusion is minimal; but water warmer than the air induces vigorous diffusion. The applicability of three empirical methods for determining the horizontal eddy diffusivity coefficient in the Gaussian plume formula was evaluated with the estimated standard deviation of the crosswind distribution of material in the plume from the LANDSAT imagery. The vertical diffusion coefficient in stable conditions is estimated using Weinstock's formulation. These results form a data base for use in the development and validation of meso scale atmospheric diffusion models.

  9. The Green Propellant Infusion Mission Thruster Performance Testing for Plume Diagnostics

    Science.gov (United States)

    Deans, Matthew C.; Reed, Brian D.; Arrington, Lynn A.; Williams, George J.; Kojima, Jun J.; Kinzbach, McKenzie I.; McLean, Christopher H.

    2014-01-01

    The Green Propellant Infusion Mission (GPIM) is sponsored by NASA's Space Technology Mission Directorate (STMD) Technology Demonstration Mission (TDM) office. The goal of GPIM is to advance the technology readiness level of a green propulsion system, specifically, one using the monopropellant, AF-M315E, by demonstrating ground handling, spacecraft processing, and on-orbit operations. One of the risks identified for GPIM is potential contamination of sensitive spacecraft surfaces from the effluents in the plumes of AF-M315E thrusters. NASA Glenn Research Center (GRC) is conducting activities to characterize the effects of AF-M315E plume impingement and deposition. GRC has established individual plume models of the 22-N and 1-N thrusters that will be used on the GPIM spacecraft. The model simulations will be correlated with plume measurement data from Laboratory and Engineering Model 22-N, AF-M315E thrusters. The thrusters are currently being tested in a small rocket, altitude facility at NASA GRC. A suite of diagnostics, including Raman spectroscopy, Rayleigh spectroscopy, and Schlieren imaging are being used to acquire plume measurements of AF-M315E thrusters. Plume data will include temperature, velocity, relative density, and species concentration. The plume measurement data will be compared to the corresponding simulations of the plume model. The GRC effort will establish a data set of AF-M315E plume measurements and a plume model that can be used for future AF-M315E applications.

  10. Large-Eddy Simulation of pollutant dispersion in downtown Montreal: Evaluation of the convective and turbulent mass fluxes

    NARCIS (Netherlands)

    Gousseau, P.; Blocken, B.J.E.; Stathopoulos, T.; Heijst, van G.J.F.; Seppelt, R.; Voinov, A.A.; Lange, S.; Bankamp, D.

    2012-01-01

    Abstract: Large-Eddy Simulation of pollutant dispersion from a stack on the roof of a low-rise building in downtown Montreal is performed. Two wind directions are considered, with different wind flow patterns and plume behaviours. The resulting mean concentration field is observed and analysed with

  11. Soluble and insoluble pollutants in fog and rime water samples

    Czech Academy of Sciences Publication Activity Database

    Fišák, Jaroslav; Stoyanova, V.; Chaloupecký, Pavel; Řezáčová, Daniela; Tsacheva, Ts.; Kupenova, T.; Marinov, M.

    2009-01-01

    Roč. 4, Sp. Iss. 2 (2009), S123-S130 ISSN 1801-5395 R&D Projects: GA ČR GA205/09/1918; GA AV ČR 1QS200420562 Institutional research plan: CEZ:AV0Z30420517 Keywords : fog water * rime water * pollutant concentration Subject RIV: DG - Athmosphere Sciences, Meteorology

  12. Biodegradation at Dynamic Plume Fringes: Mixing Versus Reaction Control

    Science.gov (United States)

    Cirpka, O. A.; Eckert, D.; Griebler, C.; Haberer, C.; Kürzinger, P.; Bauer, R.; Mellage, A.

    2014-12-01

    Biodegradation of continuously emitted plumes is known to be most pronounced at the plume fringe, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. Under steady-state conditions, physical mixing of contaminant and electron acceptor by transverse dispersion was shown to be the major bottleneck for biodegradation, with plume lengths scaling inversely with the bulk transverse dispersivity in quasi two-dimensional settings. Under these conditions, the presence of suitable microbes is essential but the biokinetic parameters do not play an important role. When the location of the plume shifts (caused, e.g., by a fluctuating groundwater table), however, the bacteria are no more situated at the plume fringe and biomass growth, decay, activation and deactivation determine the time lag until the fringe-controlled steady state is approached again. During this time lag, degradation is incomplete. The objective of the presented study was to analyze to which extent flow and transport dynamics diminish effectiveness of fringe-controlled biodegradation and which microbial processes and related biokinetic parameters determine the system response in overall degradation to hydraulic fluctuations. We performed experiments in quasi-two-dimensional flow through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth and maintenance (often subsumed as "biomass decay") microbial dormancy (that is, change into a metabolically inactive state) and

  13. The Entrainment Rate for Buoyant Plumes in a Crossflow

    Science.gov (United States)

    Devenish, B. J.; Rooney, G. G.; Webster, H. N.; Thomson, D. J.

    2010-03-01

    We consider large-eddy simulations (LES) of buoyant plumes from a circular source with initial buoyancy flux F 0 released into a stratified environment with constant buoyancy frequency N and a uniform crossflow with velocity U. We make a systematic comparison of the LES results with the mathematical theory of plumes in a crossflow. We pay particular attention to the limits {tilde{U}≪1} and {tilde{U}≫ 1}, where {tilde{U}=U/(F_0 N)^{1/4}}, for which analytical results are possible. For {tilde{U}≫ 1}, the LES results show good agreement with the well-known two-thirds law for the rise in height of the plume. Sufficiently far above the source, the centreline vertical velocity of the LES plumes is consistent with the analytical z -1/3 and z -1/2 scalings for respectively {tilde{U}≪ 1} and {tilde{U}≫ 1}. In the general case, where the entrainment is assumed to be the sum of the contributions from the horizontal and vertical velocity components, we find that the discrepancy between the LES data and numerical solutions of the plume equations is largest for {tilde{U}=O(1)}. We propose a modified additive entrainment assumption in which the contributions from the horizontal and vertical velocity components are not equally weighted. We test this against observations of the plume generated by the Buncefield fire in the U.K. in December 2005 and find that the results compare favourably. We also show that the oscillations of the plume as it settles down to its final rise height may be attenuated by the radiation of gravity waves. For {tilde{U}≪ 1} the oscillations decay rapidly due to the transport of energy away from the plume by gravity waves. For {tilde{U}>rsim 1} the gravity waves travel in the same direction and at the same speed as the flow. In this case, the oscillations of the plume do not decay greatly by radiation of gravity waves.

  14. The planet beyond the plume hypothesis

    Science.gov (United States)

    Smith, Alan D.; Lewis, Charles

    1999-12-01

    Acceptance of the theory of plate tectonics was accompanied by the rise of the mantle plume/hotspot concept which has come to dominate geodynamics from its use both as an explanation for the origin of intraplate volcanism and as a reference frame for plate motions. However, even with a large degree of flexibility permitted in plume composition, temperature, size, and depth of origin, adoption of any limited number of hotspots means the plume model cannot account for all occurrences of the type of volcanism it was devised to explain. While scientific protocol would normally demand that an alternative explanation be sought, there have been few challenges to "plume theory" on account of a series of intricate controls set up by the plume model which makes plumes seem to be an essential feature of the Earth. The hotspot frame acts not only as a reference but also controls plate tectonics. Accommodating plumes relegates mantle convection to a weak, sluggish effect such that basal drag appears as a minor, resisting force, with plates having to move themselves by boundary forces and continents having to be rifted by plumes. Correspondingly, the geochemical evolution of the mantle is controlled by the requirement to isolate subducted crust into plume sources which limits potential buffers on the composition of the MORB-source to plume- or lower mantle material. Crustal growth and Precambrian tectonics are controlled by interpretations of greenstone belts as oceanic plateaus generated by plumes. Challenges to any aspect of the plume model are thus liable to be dismissed unless a counter explanation is offered across the geodynamic spectrum influenced by "plume theory". Nonetheless, an alternative synthesis can be made based on longstanding petrological evidence for derivation of intraplate volcanism from volatile-bearing sources (wetspots) in conjunction with concepts dismissed for being incompatible or superfluous to "plume theory". In the alternative Earth, the sources for

  15. In-situ treatment of a mixed hydrocarbon plume through a permeable reactive barrier and enhanced bio-remediation

    International Nuclear Information System (INIS)

    Aglietto, I.; Bretti, L.L.

    2005-01-01

    Groundwater is frequently polluted with mixtures of contaminants that are amenable to different types of remediation. One example is the combination of petroleum hydrocarbons (mostly BTEX) and chlorinated solvents (chlorinated ethenes and propanes), as it occurs in the groundwater beneath the industrial site that is the objective of the present case study. The site is located in Italy near a main river (Arno), which is supposed to be the final recipient of the contamination and where a possible exposure might take place. The aim of the treatment is the plume containment within the site boundaries in order to avoid further migration of the contaminants towards the river. The design of the remediation system was based on an extensive site characterization that included - but was not limited to - the following information: geological and geochemical, microbiological and hydrological data, together with analytical data (i.e. contaminant concentrations). Pilot tests were also implemented in order to collect the necessary parameters for the full-scale treatment design and calibration. The site was contaminated by a mixed plume of more than 30 different contaminants, ranging from BTEX, to MTBE, to PAH, to chlorinated solvents. The concentration peaks were in the order of 1-100 mg/l for each contaminant. Petroleum hydrocarbons are quickly degradable through oxidative mechanisms (especially aerobic biodegradation), whereas fully-chlorinated compounds are only degradable via reductive pathways. A mixed plume of both types of contaminants therefore requires a combined approach with the application of different treatment technologies. The remediation strategy elaborated combines a permeable reactive barrier (PRB) in a funnel and gate configuration for the down-gradient plume containment, with the enhanced bio-remediation of the contaminants for the control of the plume boundaries and for the abatement of the concentration peaks. Pilot tests were carried out in order to assess

  16. Ablation plume dynamics in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during the expa......The expansion of a plume in a background gas of pressure comparable to that used in pulsed laser deposition (PLD) has been analyzed in terms of the model of Predtechensky and Mayorov (PM). This approach gives a relatively clear and simple description of the essential hydrodynamics during...... the expansion. The model also leads to an insightful treatment of the stopping behavior in dimensionless units for plumes and background gases of different atomic/molecular masses. The energetics of the plume dynamics can also be treated with this model. Experimental time-of-flight data of silver ions in a neon...... background gas show a fair agreement with predictions from the PM-model. Finally we discuss the validity of the model, if the work done by the pressure of the background gas is neglected....

  17. Measurements of air pollution emission factors for marine transportation in SECA

    Directory of Open Access Journals (Sweden)

    B. Alföldy

    2013-07-01

    Full Text Available The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg−1 fuel was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg−1 fuel, and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel−1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  18. Large-scale upper tropospheric pollution observed by MIPAS HCN and C2H6 global distributions

    Science.gov (United States)

    Glatthor, N.; von Clarmann, T.; Stiller, G. P.; Funke, B.; Koukouli, M. E.; Fischer, H.; Grabowski, U.; Höpfner, M.; Kellmann, S.; Linden, A.

    2009-12-01

    We present global upper tropospheric HCN and C2H6 amounts derived from MIPAS/ENVISAT limb emission spectra. HCN and C2H6 are retrieved in the spectral regions 715.5-782.7 cm-1 and 811.5-835.7 cm-1, respectively. The datasets consist of 54 days between September 2003 and March 2004. This period covers the peak and decline of the southern hemispheric biomass burning period and some months thereafter. HCN is a nearly unambiguous tracer of biomass burning with an assumed tropospheric lifetime of several months. Indeed, the most significant feature in the MIPAS HCN dataset is an upper tropospheric plume of enhanced values caused by southern hemispheric biomass burning, which in September and October 2003 extended from tropical South America over Africa, Australia to the Southern Pacific. The spatial extent of this plume agrees well with the MOPITT CO distribution of September 2003. Further there is good agreement with the shapes and mixing ratios of the southern hemispheric HCN and C2H6 fields measured by the ACE experiment between September and November 2005. The MIPAS HCN plume extended from the lowermost observation height of 8 km up to about 16 km altitude, with maximum values of 500-600 pptv in October 2003. It was still clearly visible in December 2003, but had strongly decreased by March 2004, confirming the assumed tropospheric lifetime. The main sources of C2H6 are production and transmission of fossil fuels, followed by biofuel use and biomass burning. The C2H6 distribution also clearly reflected the southern hemispheric biomass burning plume and its seasonal variation, with maximum amounts of 600-700 pptv. Generally there was good spatial overlap between the southern hemispheric distributions of both pollution tracers, except for the region between Peru and the mid-Pacific. Here C2H6was considerably enhanced, whereas the HCN amounts were low. Backward trajectory calculations suggested that industrial pollution was responsible for the elevated C2H6

  19. Large-scale upper tropospheric pollution observed by MIPAS HCN and C2H6 global distributions

    Directory of Open Access Journals (Sweden)

    A. Linden

    2009-12-01

    Full Text Available We present global upper tropospheric HCN and C2H6 amounts derived from MIPAS/ENVISAT limb emission spectra. HCN and C2H6 are retrieved in the spectral regions 715.5–782.7 cm−1 and 811.5–835.7 cm−1, respectively. The datasets consist of 54 days between September 2003 and March 2004. This period covers the peak and decline of the southern hemispheric biomass burning period and some months thereafter. HCN is a nearly unambiguous tracer of biomass burning with an assumed tropospheric lifetime of several months. Indeed, the most significant feature in the MIPAS HCN dataset is an upper tropospheric plume of enhanced values caused by southern hemispheric biomass burning, which in September and October 2003 extended from tropical South America over Africa, Australia to the Southern Pacific. The spatial extent of this plume agrees well with the MOPITT CO distribution of September 2003. Further there is good agreement with the shapes and mixing ratios of the southern hemispheric HCN and C2H6 fields measured by the ACE experiment between September and November 2005. The MIPAS HCN plume extended from the lowermost observation height of 8 km up to about 16 km altitude, with maximum values of 500–600 pptv in October 2003. It was still clearly visible in December 2003, but had strongly decreased by March 2004, confirming the assumed tropospheric lifetime. The main sources of C2H6 are production and transmission of fossil fuels, followed by biofuel use and biomass burning. The C2H6 distribution also clearly reflected the southern hemispheric biomass burning plume and its seasonal variation, with maximum amounts of 600–700 pptv. Generally there was good spatial overlap between the southern hemispheric distributions of both pollution tracers, except for the region between Peru and the mid-Pacific. Here C2H6was considerably enhanced, whereas the HCN amounts were low. Backward trajectory calculations suggested that industrial pollution was responsible

  20. Subsurface oil release field experiment - observations and modelling of subsurface plume behaviour

    International Nuclear Information System (INIS)

    Rye, H.; Brandvik, P.J.; Reed, M.

    1996-01-01

    An experiment was conducted at sea, in which oil was released from 107 metres depth, in order to study plume behaviour. The objective of the underwater release was to simulate a pipeline leakage without gas and high pressure and to study the behaviour of the rising plume. A numerical model for the underwater plume behaviour was used for comparison with field data. The expected path of the plume, the time expected for the plume to reach the sea surface and the width of the plume was modelled. Field data and the numerical model were in good agreement. 10 refs., 2 tabs., 9 figs

  1. Observed rise of visible plumes from hyperbolic natural draft cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, P T [Smith-Singer Meteorologists, Inc., Amityville, NY; Seymour, D E; Butler, M J; Kramer, M L; Smith, M E; Frankenberg, T T

    1976-01-01

    The behavior of natural draft cooling tower plumes and related meteorological variables have been measured from aircraft near three major plants of the American Electric Power System. The rise of those plumes which persisted long enough to reach a stabilized height depended primarily upon the height of the capping inversion aloft. All such plumes rose to elevations of 425 m or more above grade. No significant relationships between plume rise and wind speed, plant load, or ambient temperature were found. We conclude that simple temperature humidity soundings in the vicinity of the towers would serve as effective predictors of plume rise and persistence.

  2. Appearance property and mechanism of plume produced by pulsed ultraviolet laser ablating copper

    International Nuclear Information System (INIS)

    Huang Qingju; Li Fuquan; Wang Honghua

    2008-01-01

    Time-resolved measurements of plume emission spectra by pulsed ultraviolet laser ablating copper in neon were analyzed, and the photographs of plume from laser ablating copper were taken. The experimental results show that plume has different colours in different ranges. At low pressure the centre layer and middle layer colours of plume are mixed colour, and the outer layer colours of plume are yellow and green. At middle pressure the centre layer and middle layer colours of plume are white, and the outer layer colour of plume is pea green. At high pressure the centre layer and middle layer colours of plume are white, and the outer layer colour of plume is faintness green. The plume range is pressed with the rising of ambient gas pressure, and the range colour gets thin with the rising of ambient gas pressure. The plume excitation radiation mechanism in pulsed ultraviolet laser ablating copper was discussed. The primary excitation radiation mechanism in plume is electron collision energy transfer and atom collision energy transfer at low pressure and middle pressure, and it is electrons Bremsstrahlung and recombination excitation radiation of electron and ion at high pressure. The model can be used to explain the experimental result qualitatively. (authors)

  3. Vertically averaged approaches for CO 2 migration with solubility trapping

    KAUST Repository

    Gasda, S. E.

    2011-05-20

    The long-term storage security of injected carbon dioxide (CO2) is an essential component of geological carbon sequestration operations. In the postinjection phase, the mobile CO2 plume migrates in large part because of buoyancy forces, following the natural topography of the geological formation. The primary trapping mechanisms are capillary and solubility trapping, which evolve over hundreds to thousands of years and can immobilize a significant portion of the mobile CO2 plume. However, both the migration and trapping processes are inherently complex, spanning multiple spatial and temporal scales. Using an appropriate model that can capture both large- and small-scale effects is essential for understanding the role of these processes on the long-term storage security of CO2 sequestration operations. Traditional numerical models quickly become prohibitively expensive for the type of large-scale, long-term modeling that is necessary for characterizing the migration and immobilization of CO2 during the postinjection period. We present an alternative modeling option that combines vertically integrated governing equations with an upscaled representation of the dissolution-convection process. With this approach, we demonstrate the effect of different modeling choices for typical large-scale geological systems and show that practical calculations can be performed at the temporal and spatial scales of interest. Copyright 2011 by the American Geophysical Union.

  4. Wireless Sensor Network Based Subsurface Contaminant Plume Monitoring

    Science.gov (United States)

    2012-04-16

    Sensor Network (WSN) to monitor contaminant plume movement in naturally heterogeneous subsurface formations to advance the sensor networking based...time to assess the source and predict future plume behavior. This proof-of-concept research aimed at demonstrating the use of an intelligent Wireless

  5. Can molecular diffusion explain Space Shuttle plume spreading?

    Science.gov (United States)

    Meier, R. R.; Plane, John M. C.; Stevens, Michael H.; Paxton, L. J.; Christensen, A. B.; Crowley, G.

    2010-04-01

    The satellite-borne Global Ultraviolet Imager (GUVI) has produced more than 20 images of NASA Space Shuttle main engine plumes in the lower thermosphere. These reveal atomic hydrogen and, by inference, water vapor transport over hemispherical-scale distances with speeds much faster than expected from models of thermospheric wind motions. Furthermore, the hydrogen plumes expand rapidly. We find rates that exceed the horizontal diffusion speed at nominal plume altitudes of 104-112 km. Kelley et al. (2009) have proposed a 2-D turbulence mechanism to explain the observed spreading rates (and rapid advection) of the plumes. But upon further investigation, we conclude that H atom diffusion can indeed account for the observed expansion rates by recognizing that vertical diffusion quickly conveys atoms to higher altitudes where horizontal diffusion is much more rapid. We also find evidence for H atom production directly during the Shuttle's main engine burn.

  6. Impact of Sediment-Bound Iron on Redox Buffering in a Landfill Leachate Polluted Aquifer (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Heron, Gorm; Christensen, Thomas Højlund

    1995-01-01

    Sediments sampled along a central flow line of the leachate pollution plume at the Vejen Landfill, Denmark, were characterized in detail with respect to the forms and pools of Fe(ll) and Fe(lll). After 15 yr of leaching, redox reactions had diminished the pool of iron(ll1) oxides and hydroxides...

  7. Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology

    Directory of Open Access Journals (Sweden)

    R. G. Stevens

    2012-01-01

    Full Text Available New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulfur sources may be an important source of particles in the atmosphere. It remains unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are 10s of kilometers and larger. The predictive power of these models is thus limited by the resultant uncertainties in aerosol size distributions. In this paper, we focus on sub-grid sulfate aerosol processes within coal-fired power plant plumes: the sub-grid oxidation of SO2 with condensation of H2SO4 onto newly-formed and pre-existing particles. We have developed a modeling framework with aerosol microphysics in the System for Atmospheric Modelling (SAM, a Large-Eddy Simulation/Cloud-Resolving Model (LES/CRM. The model is evaluated against aircraft observations of new-particle formation in two different power-plant plumes and reproduces the major features of the observations. We show how the downwind plume aerosols can be greatly modified by both meteorological and background aerosol conditions. In general, new-particle formation and growth is greatly reduced during polluted conditions due to the large pre-existing aerosol surface area for H2SO4 condensation and particle coagulation. The new-particle formation and growth rates are also a strong function of the amount of sunlight and NOx since both control OH concentrations. The results of this study highlight the importance for improved sub-grid particle formation schemes in regional and global aerosol models.

  8. Analysis of plume rise data from five TVA steam plants

    International Nuclear Information System (INIS)

    Anfossi, D.

    1985-01-01

    A large data set containing the measurements of the rise of plumes emitted by five TVA steam plants was examined. Particular attention was paid to the problem of the merging of the plumes emitted by adjacent stacks and to the role played by the wind angle in this respect. It was demonstrated that there is a noticeable rise enhancement of merged plumes with respect to single emissions, both in neutral and in stable conditions, as far as transversal and parallel plumes are concerned. For plumes advected normal to the row of the stacks the enhancement is noticeable only in the final stage of rise. The existence of a critical angle for merging suggested enhancement is noticeable only in the final stage of rise. The existence of a critical angle for merging suggested by Briggs was examined. Finally, a formula to describe plume rise in the transitional and in the final phase, both in neutral and stable conditions, is proposed; it was obtained by interpolation of two familiar Brigg's equations

  9. Airborne Gamma-ray Measurements in the Chernobyl Plume

    DEFF Research Database (Denmark)

    Grasty, R. L.; Hovgaard, Jens; Multala, J.

    1997-01-01

    On 29 April 1986, the Geological Survey of Finland (GSF) survey aircraft with a gamma ray spectrometer flew through a radioactive plume from the Chernobyl nuclear accident. The aircraft became contaminated and the gamma spectrometer measured radioactivity in the plume as well as radioactivity...

  10. EM Modelling of RF Propagation Through Plasma Plumes

    Science.gov (United States)

    Pandolfo, L.; Bandinelli, M.; Araque Quijano, J. L.; Vecchi, G.; Pawlak, H.; Marliani, F.

    2012-05-01

    Electric propulsion is a commercially attractive solution for attitude and position control of geostationary satellites. Hall-effect ion thrusters generate a localized plasma flow in the surrounding of the satellite, whose impact on the communication system needs to be qualitatively and quantitatively assessed. An electromagnetic modelling tool has been developed and integrated into the Antenna Design Framework- ElectroMagnetic Satellite (ADF-EMS). The system is able to guide the user from the plume definition phases through plume installation and simulation. A validation activity has been carried out and the system has been applied to the plume modulation analysis of SGEO/Hispasat mission.

  11. Laser beam-plasma plume interaction during laser welding

    Science.gov (United States)

    Hoffman, Jacek; Moscicki, Tomasz; Szymanski, Zygmunt

    2003-10-01

    Laser welding process is unstable because the keyhole wall performs oscillations which results in the oscillations of plasma plume over the keyhole mouth. The characteristic frequencies are equal to 0.5-4 kHz. Since plasma plume absorbs and refracts laser radiation, plasma oscillations modulate the laser beam before it reaches the workpiece. In this work temporary electron densities and temperatures are determined in the peaks of plasma bursts during welding with a continuous wave CO2 laser. It has been found that during strong bursts the plasma plume over the keyhole consists of metal vapour only, being not diluted by the shielding gas. As expected the values of electron density are about two times higher in peaks than their time-averaged values. Since the plasma absorption coefficient scales as ~N2e/T3/2 (for CO2 laser radiation) the results show that the power of the laser beam reaching the metal surface is modulated by the plasma plume oscillations. The attenuation factor equals 4-6% of the laser power but it is expected that it is doubled by the refraction effect. The results, together with the analysis of the colour pictures from streak camera, allow also interpretation of the dynamics of the plasma plume.

  12. DeepBlow - a Lagrangian plume model for deep water blowouts

    International Nuclear Information System (INIS)

    Johansen, Oeistein

    2000-01-01

    This paper presents a sub-sea blowout model designed with special emphasis on deep-water conditions. The model is an integral plume model based on a Lagrangian concept. This concept is applied to multiphase discharges in the formation of water, oil and gas in a stratified water column with variable currents. The gas may be converted to hydrate in combination with seawater, dissolved into the plume water, or leaking out of the plume due to the slip between rising gas bubbles and the plume trajectory. Non-ideal behaviour of the gas is accounted for by the introduction of pressure- and temperature-dependent compressibility z-factor in the equation of state. A number of case studies are presented in the paper. One of the cases (blowout from 100 m depth) is compared with observations from a field experiment conducted in Norwegian waters in June 1996. The model results are found to compare favourably with the field observations when dissolution of gas into seawater is accounted in the model. For discharges at intermediate to shallow depths (100-250 m), the two major processes limiting plume rise will be: (a) dissolution of gas into ambient water, or (b) bubbles rising out of the inclined plume. These processes tend to be self-enforcing, i.e., when a gas is lost by either of these processes, plume rise tends to slow down and more time will be available for dissolution. For discharges in deep waters (700-1500 m depth), hydrate formation is found to be a dominating process in limiting plume rise. (Author)

  13. A study of space shuttle plumes in the lower thermosphere

    Science.gov (United States)

    Meier, R. R.; Stevens, Michael H.; Plane, John M. C.; Emmert, J. T.; Crowley, G.; Azeem, I.; Paxton, L. J.; Christensen, A. B.

    2011-12-01

    During the space shuttle main engine burn, some 350 t of water vapor are deposited at between 100 and 115 km. Subsequent photodissociation of water produces large plumes of atomic hydrogen that can expand rapidly and extend for thousands of kilometers. From 2002 to 2007, the Global Ultraviolet Imager (GUVI) on NASA's Thermosphere Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite imaged many of these hydrogen plumes at Lyman α (121.567 nm) while viewing in the nadir. The images reveal rapid plume expansion and occasional very fast transport to both north and south polar regions. Some plumes persist for up to 6 d. Near-simultaneous direct detections of water vapor were made with the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) instrument, also on TIMED. We compare the spreading of the hydrogen plume with a two-dimensional model that includes photodissociation as well as both vertical and horizontal diffusion. Molecular diffusion appears to be sufficient to account for the horizontal expansion, although wind shears and turbulent mixing may also contribute. We compare the bulk motion of the observed plumes with wind climatologies derived from satellite observations. The plumes can move much faster than predictions of wind climatologies. But dynamical processes not contained in wind climatologies, such as the quasi-two-day wave, can account for at least some of the high speed observations. The plume phenomena raise a number of important questions about lower thermospheric and mesospheric processes, ranging from dynamics and chemistry to polar mesospheric cloud formation and climatology.

  14. Hydrocarbon Degradation and Lead Solubility in a Soil Polluted with Lead and Used Motor Oil Treated by Composting and Phytoremediation.

    Science.gov (United States)

    Escobar-Alvarado, L F; Vaca-Mier, M; López, R; Rojas-Valencia, M N

    2018-02-01

    Used lubricant oils and metals can be common soil pollutants in abandoned sites. When soil is contaminated with various hazardous wastes, the efficiency of biological treatments could be affected. The purpose of this work was to investigate the effect of combining phytoremediation and composting on the efficiency of hydrocarbon degradation and lead solubility in a soil contaminated with 31,823 mg/kg of total petroleum hydrocarbon (TPH) from used motor oil and 8260 mg/kg of lead. Mexican cactus (Opuntia ficus indica) and yard trimmings were added in the composting process, and lucerne (Medicago sativa) was used in the phytoremediation process. After a 9 week composting process, only 13% of the initial TPH concentration was removed. The following 20 week phytoremediation process removed 48% of TPH. The highest TPH degradation percentage (66%), was observed in the experiment with phytoremediation only. This work demonstrates sustainable technologies, such as biological treatments, represent low-cost options for remediation; however, they are not frequently used because they require long periods of time for success.

  15. Studies of the environmental impact of evaporative cooling tower plumes

    International Nuclear Information System (INIS)

    Thomson, D.W.

    1978-01-01

    This ongoing research program of the environmental impact of natural-draft evaporative cooling tower plumes consists principally of a comprehensive series of airborne measurements of a variety of the physical characteristics of the plumes and, to a lesser extent, of preliminary studies of remote sodar plume probing techniques and the development of simplified dynamical numerical models suitable for use in conducting field measurement programs. The PSU Doppler sodar was used at the Keystone Power Plant in southwestern Pennsylvania for an extended series of remote measurements of the characteristics of plume turbulent temperature and velocity fluctuations and results are discussed

  16. Fractal analysis: A new tool in transient volcanic ash plume characterization.

    Science.gov (United States)

    Tournigand, Pierre-Yves; Peña Fernandez, Juan Jose; Taddeucci, Jacopo; Perugini, Diego; Sesterhenn, Jörn

    2017-04-01

    Transient volcanic plumes are time-dependent features generated by unstable eruptive sources. They represent a threat to human health and infrastructures, and a challenge to characterize due to their intrinsic instability. Plumes have been investigated through physical (e.g. visible, thermal, UV, radar imagery), experimental and numerical studies in order to provide new insights about their dynamics and better anticipate their behavior. It has been shown experimentally that plume dynamics is strongly dependent to source conditions and that plume shape evolution holds key to retrieve these conditions. In this study, a shape evolution analysis is performed on thermal high-speed videos of volcanic plumes from three different volcanoes Sakurajima (Japan), Stromboli (Italy) and Fuego (Guatemala), recorded with a FLIR SC655 thermal camera during several field campaigns between 2012 and 2016. To complete this dataset, three numerical gas-jet simulations at different Reynolds number (2000, 5000 and 10000) have been used in order to set reference values to the natural cases. Turbulent flow shapes are well known to feature scale-invariant structures and a high degree of complexity. For this reason we characterized the bi-dimensional shape of natural and synthetic plumes by using a fractal descriptor. Such method has been applied in other studies on experimental turbulent jets as well as on atmospheric clouds and have shown promising results. At each time-step plume contour has been manually outlined and measured using the box-counting method. This method consists in covering the image with squares of variable sizes and counting the number of squares containing the plume outline. The negative slope of the number of squares in function of their size in a log-log plot gives the fractal dimension of the plume at a given time. Preliminary results show an increase over time of the fractal dimension for natural volcanic plume as well as for the numerically simulated ones, but at

  17. Source identification and airborne chemical characterisation of aerosol pollution from long-range transport over Greenland during POLARCAT summer campaign 2008

    Science.gov (United States)

    Schmale, J.; Schneider, J.; Ancellet, G.; Quennehen, B.; Stohl, A.; Sodemann, H.; Burkhart, J. F.; Hamburger, T.; Arnold, S. R.; Schwarzenboeck, A.; Borrmann, S.; Law, K. S.

    2011-10-01

    We deployed an aerosol mass spectrometer during the POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport) summer campaign in Greenland in June/July 2008 on the research aircraft ATR-42. Online size resolved chemical composition data of submicron aerosol were collected up to 7.6 km altitude in the region 60 to 71° N and 40 to 60° W. Biomass burning (BB) and fossil fuel combustion (FF) plumes originating from North America, Asia, Siberia and Europe were sampled. Transport pathways of detected plumes included advection below 700 hPa, air mass uplifting in warm conveyor belts, and high altitude transport in the upper troposphere. By means of the Lagrangian particle dispersion model FLEXPART, trace gas analysis of O3 and CO, particle size distributions and aerosol chemical composition 48 pollution events were identified and classified into five chemically distinct categories. Aerosol from North American BB consisted of 22% particulate sulphate, while with increasing anthropogenic and Asian influence aerosol in Asian FF dominated plumes was composed of up to 37% sulphate category mean value. Overall, it was found that the organic matter fraction was larger (85%) in pollution plumes than for background conditions (71%). Despite different source regions and emission types the particle oxygen to carbon ratio of all plume classes was around 1 indicating low-volatility highly oxygenated aerosol. The volume size distribution of out-of-plume aerosol showed markedly smaller modes than all other distributions with two Aitken mode diameters of 24 and 43 nm and a geometric standard deviation σg of 1.12 and 1.22, respectively, while another very broad mode was found at 490 nm (σg = 2.35). Nearly pure BB particles from North America exhibited an Aitken mode at 66 nm (σg = 1.46) and an accumulation mode diameter of 392 nm (σg = 1.76). An aerosol lifetime, including all processes from emission to

  18. Oceanic magmatic evolution during ocean opening under influence of mantle plume

    Science.gov (United States)

    Sushchevskaya, Nadezhda; Melanholina, Elena; Belyatsky, Boris; Krymsky, Robert; Migdisova, Natalya

    2015-04-01

    Petrology, geochemistry and geophysics as well as numerical simulation of spreading processes in plume impact environments on examples of Atlantic Ocean Iceland and the Central Atlantic plumes and Kerguelen plume in the Indian Ocean reveal: - under interaction of large plume and continental landmass the plume can contribute to splitting off individual lithosphere blocks, and their subsequent movement into the emergent ocean. At the same time enriched plume components often have geochemical characteristics of the intact continental lithosphere by early plume exposure. This is typical for trap magmatism in Antarctica, and for magmatism of North and Central Atlantic margins; - in the course of the geodynamic reconstruction under the whole region of the South Atlantic was formed (not in one step) metasomatized enriched sub-oceanic mantle with pyroxenite mantle geochemical characteristics and isotopic composition of enriched HIMU and EM-2 sources. That is typical for most of the islands in the West Antarctic. This mantle through spreading axes jumping involved in different proportions in the melting under the influence of higher-temperature rising asthenospheric lherzolite mantle; - CAP activity was brief enough (200 ± 2 Ma), but Karoo-Maud plume worked for a longer time and continued from 180 to 170 Ma ago in the main phase. Plume impact within Antarctica distributed to the South and to the East, leading to the formation of extended igneous provinces along the Transantarctic Mountains and along the east coast (Queen Maud Land province and Schirmacher Oasis). Moreover, this plume activity may be continued later on, after about 40 million years cessation, as Kerguelen plume within the newly-formed Indian Ocean, significantly affects the nature of the rift magmatism; - a large extended uplift in the eastern part of the Indian Ocean - Southeastern Indian Ridge (SEIR) was formed on the ancient spreading Wharton ridge near active Kerguelen plume. The strongest plume

  19. Ozone production efficiency of a ship-plume: ITCT 2K2 case study.

    Science.gov (United States)

    Kim, Hyun S; Kim, Yong H; Han, Kyung M; Kim, Jhoon; Song, Chul H

    2016-01-01

    Ozone production efficiency (OPE) of ship plume was first evaluated in this study, based on ship-plume photochemical/dynamic model simulations and the ship-plume composition data measured during the ITCT 2K2 (Intercontinental Transport and Chemical Transformation 2002) aircraft campaign. The averaged instantaneous OPEs (OPE(i)‾) estimated via the ship-plume photochemical/dynamic modeling for the ITCT 2K2 ship-plume ranged between 4.61 and 18.92, showing that the values vary with the extent of chemical evolution (or chemical stage) of the ship plume and the stability classes of the marine boundary layer (MBL). Together with OPE(i)‾, the equivalent OPEs (OPE(e)‾) for the entire ITCT 2K2 ship-plume were also estimated. The OPE(e)‾ values varied between 9.73 (for the stable MBL) and 12.73 (for the moderately stable MBL), which agreed well with the OPE(e)‾ of 12.85 estimated based on the ITCT 2K2 ship-plume observations. It was also found that both the model-simulated and observation-based OPE(e)‾ inside the ship-plume were 0.29-0.38 times smaller than the OPE(e)‾ calculated/measured outside the ITCT 2K2 ship-plume. Such low OPEs insides the ship plume were due to the high levels of NO and non-liner ship-plume photochemistry. Possible implications of this ship-plume OPE study in the global chemistry-transport modeling are also discussed. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Apollo Video Photogrammetry Estimation Of Plume Impingement Effects

    Science.gov (United States)

    Immer, Christopher; Lane, John; Metzger, Philip T.; Clements, Sandra

    2008-01-01

    The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing in order to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modem photogrammetry techniques. The authors have used the digitized videos to quantify plume impingement effects of the landing exhaust on the lunar surface. The dust ejection angle from the plume is estimated at 1-3 degrees. The lofted particle density is estimated at 10(exp 8)- 10(exp 13) particles per cubic meter. Additionally, evidence for ejection of large 10-15 cm sized objects and a dependence of ejection angle on thrust are presented. Further work is ongoing to continue quantitative analysis of the landing videos.

  1. Air pollution upregulates endothelial cell procoagulant activity via ultrafine particle-induced oxidant signaling and tissue factor expression.

    Science.gov (United States)

    Snow, S J; Cheng, W; Wolberg, A S; Carraway, M S

    2014-07-01

    Air pollution exposure is associated with cardiovascular events triggered by clot formation. Endothelial activation and initiation of coagulation are pathophysiological mechanisms that could link inhaled air pollutants to vascular events. Here we investigated the underlying mechanisms of increased endothelial cell procoagulant activity following exposure to soluble components of ultrafine particles (soluble UF). Human coronary artery endothelial cells (HCAEC) were exposed to soluble UF and assessed for their ability to trigger procoagulant activity in platelet-free plasma. Exposed HCAEC triggered earlier thrombin generation and faster fibrin clot formation, which was abolished by an anti-tissue factor (TF) antibody, indicating TF-dependent effects. Soluble UF exposure increased TF mRNA expression without compensatory increases in key anticoagulant proteins. To identify early events that regulate TF expression, we measured endothelial H2O2 production following soluble UF exposure and identified the enzymatic source. Soluble UF exposure increased endothelial H2O2 production, and antioxidants attenuated UF-induced upregulation of TF, linking the procoagulant responses to reactive oxygen species (ROS) formation. Chemical inhibitors and RNA silencing showed that NOX-4, an important endothelial source of H2O2, was involved in UF-induced upregulation of TF mRNA. These data indicate that soluble UF exposure induces endothelial cell procoagulant activity, which involves de novo TF synthesis, ROS production, and the NOX-4 enzyme. These findings provide mechanistic insight into the adverse cardiovascular effects associated with air pollution exposure. Published by Oxford University Press on behalf of Toxicological Sciences 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  2. Dynamics of vapor plume in transient keyhole during laser welding of stainless steel: Local evaporation, plume swing and gas entrapment into porosity

    Science.gov (United States)

    Pang, Shengyong; Chen, Xin; Shao, Xinyu; Gong, Shuili; Xiao, Jianzhong

    2016-07-01

    In order to better understand the local evaporation phenomena of keyhole wall, vapor plume swing above the keyhole and ambient gas entrapment into the porosity defects, the 3D time-dependent dynamics of the metallic vapor plume in a transient keyhole during fiber laser welding is numerically investigated. The vapor dynamical parameters, including the velocity and pressure, are successfully predicted and obtain good agreements with the experimental and literature data. It is found that the vapor plume flow inside the keyhole has complex multiple directions, and this various directions characteristic of the vapor plume is resulted from the dynamic evaporation phenomena with variable locations and orientations on the keyhole wall. The results also demonstrate that because of this dynamic local evaporation, the ejected vapor plume from the keyhole opening is usually in high frequency swinging. The results further indicate that the oscillation frequency of the plume swing angle is around 2.0-8.0 kHz, which is of the same order of magnitude with that of the keyhole depth (2.0-5.0 kHz). This consistency clearly shows that the swing of the ejected vapor plume is closely associated with the keyhole instability during laser welding. Furthermore, it is learned that there is usually a negative pressure region (several hundred Pa lower than the atmospheric pressure) of the vapor flow around the keyhole opening. This pressure could lead to a strong vortex flow near the rear keyhole wall, especially when the velocity of the ejected metallic vapor from the keyhole opening is high. Under the effect of this flow, the ambient gas is involved into the keyhole, and could finally be entrapped into the bubbles within a very short time (keyhole.

  3. Production of Peroxy Nitrates in Boreal Biomass Burning Plumes over Canada During the BORTAS Campaign

    Science.gov (United States)

    Busilacchio, Marcella; Di Carlo, Piero; Aruffo, Eleonora; Biancofiore, Fabio; Salisburgo, Cesare Dari; Giammaria, Franco; Bauguitte, Stephane; Lee, James; Moller, Sarah; Hopkins, James; hide

    2016-01-01

    The observations collected during the BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) campaign in summer 2011 over Canada are analysed to study the impact of forest fire emissions on the formation of ozone (O3 and total peroxy nitrates (sigma)PNs, (sigma)ROONO2. The suite of measurements on board the BAe-146 aircraft, deployed in this campaign, allows us to calculate the production of O3 and of (sigma)PNs, a long-lived NOx reservoir whose concentration is supposed to be impacted by biomass burning emissions.In fire plumes, profiles of carbon monoxide (CO), which is a well-established tracer of pyrogenic emission, show concentration enhancements that are in strong correspondence with a significant increase of concentrations of (sigma)PNs, where as minimal increase of the concentrations of O3 and NO2 is observed. The (sigma)PN and O3 productions have been calculated using the rate constants of the first- and second-order react Pions of volatile organic compound (VOC) oxidation. The (sigma)PN and O3 productions have also been quantified by 0-D model simulation based on the Master Chemical Mechanism. Both methods show that in fire plumes the average production of (sigma)PNs and O3 are greater than in the background plumes, but the increase of (sigma)PN production is more pronounced than the O3 production. The average (sigma)PN production in fire plumes is from 7 to 12 times greater than in the background, whereas the average O3 production in fire plumes is from 2 to 5 times greater than in the background. These results suggest that, at least for boreal forest fires and for the measurements recorded during the BORTAS campaign,fire emissions impact both the oxidized NOy and O3;but (1)(sigma)PN production is amplified significantly more thanO3 production and (2) in the forest fire plumes the ratio between the O3 production and the (sigma)PN production is lower than the ratio evaluated in the background air masses, thus

  4. Production of peroxy nitrates in boreal biomass burning plumes over Canada during the BORTAS campaign

    Directory of Open Access Journals (Sweden)

    M. Busilacchio

    2016-03-01

    Full Text Available The observations collected during the BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS campaign in summer 2011 over Canada are analysed to study the impact of forest fire emissions on the formation of ozone (O3 and total peroxy nitrates ∑PNs, ∑ROONO2. The suite of measurements on board the BAe-146 aircraft, deployed in this campaign, allows us to calculate the production of O3 and of  ∑PNs, a long-lived NOx reservoir whose concentration is supposed to be impacted by biomass burning emissions. In fire plumes, profiles of carbon monoxide (CO, which is a well-established tracer of pyrogenic emission, show concentration enhancements that are in strong correspondence with a significant increase of concentrations of ∑PNs, whereas minimal increase of the concentrations of O3 and NO2 is observed. The ∑PN and O3 productions have been calculated using the rate constants of the first- and second-order reactions of volatile organic compound (VOC oxidation. The ∑PN and O3 productions have also been quantified by 0-D model simulation based on the Master Chemical Mechanism. Both methods show that in fire plumes the average production of ∑PNs and O3 are greater than in the background plumes, but the increase of ∑PN production is more pronounced than the O3 production. The average ∑PN production in fire plumes is from 7 to 12 times greater than in the background, whereas the average O3 production in fire plumes is from 2 to 5 times greater than in the background. These results suggest that, at least for boreal forest fires and for the measurements recorded during the BORTAS campaign, fire emissions impact both the oxidized NOy and O3,  but (1 ∑PN production is amplified significantly more than O3 production and (2 in the forest fire plumes the ratio between the O3 production and the ∑PN production is lower than the ratio evaluated in the background air masses, thus confirming that the

  5. Plume expansion dynamics during laser ablation of manganates in oxygen atmosphere

    International Nuclear Information System (INIS)

    Amoruso, S.; Sambri, A.; Wang, X.

    2007-01-01

    The effect of ambient gas on the expansion dynamics of the plasma plume generated by excimer laser ablation of a LaMnO 3 target is investigated by using fast photography and optical emission spectroscopy. The plume propagation in an oxygen environment is examined with pressure ranging from vacuum to few hundreds Pa. Imaging analysis of the plume emission has allowed following the changes in the plume front dynamics as a function of time and pressure. The expansion dynamics of the plume front is examined by means of a theoretical description of plume evolution and shock-wave propagation in dimensionless variables. Optical emission spectroscopy analysis showed that the oxides are mainly formed in the gas-phase through reaction of the ablated atomic species with ambient oxygen. Moreover, we observed that the formation of oxides is strongly favoured at a pressure level where the formation of a shock-wave occurs

  6. Tracing Mantle Plumes: Quantifying their Morphology and Behavior from Seismic Tomography

    Science.gov (United States)

    O'Farrell, K. A.; Eakin, C. M.; Jones, T. D.; Garcia, E.; Robson, A.; Mittal, T.; Lithgow-Bertelloni, C. R.; Jackson, M. G.; Lekic, V.; Rudolph, M. L.

    2016-12-01

    Hotspot volcanism provides a direct link between the deep mantle and the surface, but the location, depth and source of the mantle plumes that feed hotspots are highly controversial. In order to address this issue it is important to understand the journey along which plumes have travelled through the mantle. The general behavior of plumes in the mantle also has the potential to tell us about the vigor of mantle convection, net rotation of the mantle, the role of thermal versus chemical anomalies, and important bulk physical properties of the mantle such as the viscosity profile. To address these questions we developed an algorithm to trace plume-like features in shear-wave (Vs) seismic tomographic models based on picking local minima in velocity and searching for continuous features with depth. We apply this method to several of the latest tomographic models and can recover 30 or more continuous plume conduits that are >750 km long. Around half of these can be associated with a known hotspot at the surface. We study the morphology of these plume chains and find that the largest lateral deflections occur near the base of the lower mantle and in the upper mantle. We analyze the preferred orientation of the plume deflections and their gradient to infer large scale mantle flow patterns and the depth of viscosity contrasts in the mantle respectively. We also retrieve Vs profiles for our traced plumes and compare with velocity profiles predicted for different mantle adiabat temperatures. We use this to constrain the thermal anomaly associated with these plumes. This thermal anomaly is then converted to a density anomaly and an upwelling velocity is derived. We compare this to buoyancy fluxes calculated at the surface and use this in conjunction with our measured plume tilts/deflections to estimate the strength of the "mantle wind".

  7. Use of electrophoresis and immunoelectrophoresis in taxonomic and pollution studies

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Qasim, S.Z.

    Studies were conducted on the electrophoresis of blood serum and eye lens proteins of 5 fishes and immunoelectrophoresis of the soluble lens proteins of 10 fishes. The effects of a toxic pollutant (mercury) on the electrophoretic patterns...

  8. Oil characterisation: assessment of composition, risks, degradation and remediation potential of total petroleum hydrocarbons in soil

    International Nuclear Information System (INIS)

    Lookman, R.; Vanermen, G.; Van De Weghe, H.; Gemoets, J.; Van der Sterren, G.; Alphenaar, A.

    2005-01-01

    Several methods are available for the characterization of petroleum hydrocarbons. The TPHCWG (Total Petroleum Hydrocarbon Criteria Working Group) developed a method based on a silica column separation of aromatics and aliphatics and a GC-FID subdivision into equivalent-carbon fractions (EC) ('TPH-method'). This method was mainly developed for assessing human risks of oil compounds. Within NOBIS (Dutch Research program Biological In-situ Remediation), another method was developed based upon an equilibrium-experiment of the oil-polluted soil with water (column recirculation), which was further developed by TTE ('TTE-method'). This method uses measured water solubilities of individual oil components and GC-retention times yielding a subdivision of the hydrocarbons into compound classes that are relevant for assessing the remediation potential of the specific oil pollution. In this paper we present results of a research project in which we developed a new method, the 'OK-method' that combines these two procedures and allows a complete characterisation of the oil in terms of composition, (human) risks, volatility, solubility, plume behaviour (migration velocities of the soluble components) and aerobic degradation potential. (authors)

  9. Dispersal of the Pearl River plume over continental shelf in summer

    Science.gov (United States)

    Chen, Zhaoyun; Gong, Wenping; Cai, Huayang; Chen, Yunzhen; Zhang, Heng

    2017-07-01

    Satellite images of turbidity were used to study the climatological, monthly, and typical snapshot distributions of the Pearl River plume over the shelf in summer from 2003 to 2016. These images show that the plume spreads offshore over the eastern shelf and is trapped near the coast over the western shelf. Eastward extension of the plume retreats from June to August. Monthly spatial variations of the plume are characterized by eastward spreading, westward spreading, or both. Time series of monthly plume area was quantified by applying the K-mean clustering method to identify the turbid plume water. Decomposition of the 14-year monthly turbidity data by the empirical orthogonal function (EOF) analysis isolated the 1st mode in both the eastward and westward spreading pattern as the time series closely related to the Pearl River discharge, and the 2nd mode with out-of-phase turbidity anomalies over the eastern and western shelves that is associated with the prevailing wind direction. Eight typical plume types were detected from the satellite snapshots. They are characterized by coastal jet, eastward offshore spreading, westward spreading, bidirectional spreading, bulge, isolated patch, offshore branch, and offshore filaments, respectively. Their possible mechanisms are discussed.

  10. Hybrid cooling tower Neckarwestheim 2 cooling function, emission, plume dispersion

    International Nuclear Information System (INIS)

    Braeuning, G.; Ernst, G.; Maeule, R.; Necker, P.

    1990-01-01

    The fan-assisted hybrid cooling tower of the 1300 MW power plant Gemeinschafts-Kernkraftwerk Neckarwestheim 2 was designed and constructed based on results from theoretical and experimental studies and experiences from a smaller prototype. The wet part acts in counterflow. The dry part is arranged above the wet part. Each part contains 44 fans. Special attention was payed to the ducts which mix the dry into the wet plume. The cooling function and state, mass flow and contents of the emission were measured. The dispersion of the plume in the atmosphere was observed. The central results are presented in this paper. The cooling function corresponds to the predictions. The content of drifted cooling water in the plume is extremely low. The high velocity of the plume in the exit causes an undisturbed flow into the atmosphere. The hybrid operation reduces visible plumes strongly, especially in warmer and drier ambient air

  11. Groundwater contaminant plume ranking

    International Nuclear Information System (INIS)

    1988-08-01

    Containment plumes at Uranium Mill Tailings Remedial Action (UMTRA) Project sites were ranked to assist in Subpart B (i.e., restoration requirements of 40 CFR Part 192) compliance strategies for each site, to prioritize aquifer restoration, and to budget future requests and allocations. The rankings roughly estimate hazards to the environment and human health, and thus assist in determining for which sites cleanup, if appropriate, will provide the greatest benefits for funds available. The rankings are based on the scores that were obtained using the US Department of Energy's (DOE) Modified Hazard Ranking System (MHRS). The MHRS and HRS consider and score three hazard modes for a site: migration, fire and explosion, and direct contact. The migration hazard mode score reflects the potential for harm to humans or the environment from migration of a hazardous substance off a site by groundwater, surface water, and air; it is a composite of separate scores for each of these routes. For ranking the containment plumes at UMTRA Project sites, it was assumed that each site had been remediated in compliance with the EPA standards and that relict contaminant plumes were present. Therefore, only the groundwater route was scored, and the surface water and air routes were not considered. Section 2.0 of this document describes the assumptions and procedures used to score the groundwater route, and Section 3.0 provides the resulting scores for each site. 40 tabs

  12. Verification of the pollutant transport model 'MODIS' using EPRI plains site data from a tall stack

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, G; Eppel, D; Grassl, H

    1988-01-01

    A comprehensive numerical model for the simulation of pollutant dispersion from a point source into the mixing layer of the atmosphere over flat terrain is described. A moment reduction technique is used (MODIS = Moment Distribution) to combine the simplicity of the Gaussian plume description with the versatility of Eulerian grid formulations. Turbulent dispersion coefficients are parameterized in terms of mean square wind variances which in turn are obtained by a simplified second order closure model. The data base of the 'EPRI Plume Model Validation and Development Project' is used to validate the model for wind velocities above 0.5 m/s and for horizontal scales up to about one hundred kilometers. The model describes the three-dimensional structure of a plume also for stable conditions including a nighttime low level jet. For a convective planetary boundary layer it underestimates maximum ground concentration as do other models. However, it is capable of approaching measured maximum ground concentration under stable conditions.

  13. Plume tracer experiments at Hinkley Point 'A' [Nuclear Power Station] during 1987

    International Nuclear Information System (INIS)

    Foster, P.M.

    1988-11-01

    The results of the first part of a programme of plume dispersion measurements at the Hinkley Point Nuclear Power Station are described. Using SF 6 gas and pyrotechnic smoke tracer techniques developed during an earlier study at Oldbury, measurements of ground level plume behaviour out to about 4 km and elevated plume behaviour out to about 1 km have been made in a series of twelve 1 hour trials and one 15 minute trial. Whereas the Oldbury study considered passive emissions, attention in this study has been focussed on the behaviour of the buoyant shield cooling air emission. Data on plume rise and the degree of plume entrainment by the building wake and on the effects of entrainment and wind meander on plume width and concentration, are presented and discussed in relation to current modelling recommendations. A limited number of 10 minute averaged measurements of plume concentration and 41-Ar decay gamma count were also made at 2 km range and their correlation and variability examined. (author)

  14. Large-eddy simulation study of oil/gas plumes in stratified fluid with cross current

    Science.gov (United States)

    Yang, Di; Xiao, Shuolin; Chen, Bicheng; Chamecki, Marcelo; Meneveau, Charles

    2017-11-01

    Dynamics of the oil/gas plume from a subsea blowout are strongly affected by the seawater stratification and cross current. The buoyant plume entrains ambient seawater and lifts it up to higher elevations. During the rising process, the continuously increasing density difference between the entrained and ambient seawater caused by the stable stratification eventually results in a detrainment of the entrained seawater and small oil droplets at a height of maximum rise (peel height), forming a downward plume outside the rising inner plume. The presence of a cross current breaks the plume's axisymmetry and causes the outer plume to fall along the downstream side of the inner plume. The detrained seawater and oil eventually fall to a neutral buoyancy level (trap height), and disperse horizontally to form an intrusion layer. In this study, the complex plume dynamics is investigated using large-eddy simulation (LES). Various laboratory and field scale cases are simulated to explore the effect of cross current and stratification on the plume dynamics. Based on the LES data, various turbulence statistics of the plume are systematically quantified, leading to some useful insights for modeling the mean plume dynamics using integral plume models. This research is made possible by a RFP-V Grant from The Gulf of Mexico Research Initiative.

  15. Characterizing Io’s Pele, Tvashtar and Pillan plumes: Lessons learned from Hubble

    Science.gov (United States)

    Jessup, Kandis Lea; Spencer, John R.

    2012-03-01

    Hubble Space Telescope/Wide Field and Planetary Camera 2 (HST/WFPC2) images of Io obtained between 1995 and 2007 between 0.24 and 0.42 μm led to the detection of the Pele plume in reflected sunlight in 1995 and 1999; imaging of the Pele plume via absorption of jovian light in 1996 and 1999; detection of the Prometheus-type Pillan plume in reflected sunlight in 1997; and detection of the 2007 Pele-type Tvashtar plume eruption in reflected sunlight and via absorption of jovian light. Based on a detailed analysis of these observations we characterize and compare the gas and dust properties of each of the detected plumes. In each case, the brightness of the plumes in reflected sunlight is less at 0.26 μm than at 0.33 μm. Mie scattering analysis of the wavelength dependence of each plume’s reflectance signature suggests that range of particle sizes within the plumes is quite narrow. Assuming a normal distribution of particle sizes, the range of mean particle sizes is ∼0.035-0.12 μm for the 1997 Pillan eruption, ∼0.05-0.08 μm for the 1999 Pele and 2007 Tvasthar plumes, and ∼0.05-0.11 μm for the 1995 Pele plume, and in each case the standard deviation in the particle size distribution is Pele eruption released ∼109 g of SO2 dust, the 1997 Pillan eruption released ∼1010 g of SO2 dust, and the 1995 Pele plume may have released ∼1010 g of SO2 dust. Analysis of the plume absorption signatures recorded in the F255W filter bandpass (0.24-0.28 μm) indicates that the opacity of the 2007 Tvashtar plume was 2× that of the 1996 and 1999 Pele plume eruptions. While the sulfur dust density estimated for the Tvashtar from the reflected sunlight data could have produced 61% of the observed plume opacity, Pele F255W plume opacity could have resulted from the SO2 dust detected in the eruption. Accounting for the remaining F255W opacity level of the Pele and Tvasthar plumes based on SO2 and S2 gas absorption, the SO2 and S2 gas density inferred for each plume is

  16. Morphological changes in ultrafast laser ablation plumes with varying spot size.

    Science.gov (United States)

    Harilal, S S; Diwakar, P K; Polek, M P; Phillips, M C

    2015-06-15

    We investigated the role of spot size on plume morphology during ultrafast laser ablation of metal targets. Our results show that the spatial features of fs LA plumes are strongly dependent on the focal spot size. Two-dimensional self-emission images showed that the shape of the ultrafast laser ablation plumes changes from spherical to cylindrical with an increasing spot size from 100 to 600 μm. The changes in plume morphology and internal structures are related to ion emission dynamics from the plasma, where broader angular ion distribution and faster ions are noticed for the smallest spot size used. The present results clearly show that the morphological changes in the plume with spot size are independent of laser pulse width.

  17. Modeling ozone plumes observed downwind of New York City over the North Atlantic Ocean during the ICARTT field campaign

    Directory of Open Access Journals (Sweden)

    S.-H. Lee

    2011-07-01

    Full Text Available Transport and chemical transformation of well-defined New York City (NYC urban plumes over the North Atlantic Ocean were studied using aircraft measurements collected on 20–21 July 2004 during the ICARTT (International Consortium for Atmospheric Research on Transport and Transformation field campaign and WRF-Chem (Weather Research and Forecasting-Chemistry model simulations. The strong NYC urban plumes were characterized by carbon monoxide (CO mixing ratios of 350–400 parts per billion by volume (ppbv and ozone (O3 levels of about 100 ppbv near New York City on 20 July in the WP-3D in-situ and DC-3 lidar aircraft measurements. On 21 July, the two aircraft captured strong urban plumes with about 350 ppbv CO and over 150 ppbv O3 (~160 ppbv maximum about 600 km downwind of NYC over the North Atlantic Ocean. The measured urban plumes extended vertically up to about 2 km near New York City, but shrank to 1–1.5 km over the stable marine boundary layer (MBL over the North Atlantic Ocean. The WRF-Chem model reproduced ozone formation processes, chemical characteristics, and meteorology of the measured urban plumes near New York City (20 July and in the far downwind region over the North Atlantic Ocean (21 July. The quasi-Lagrangian analysis of transport and chemical transformation of the simulated NYC urban plumes using WRF-Chem results showed that the pollutants can be efficiently transported in (isentropic layers in the lower atmosphere (<2–3 km over the North Atlantic Ocean while maintaining a dynamic vertical decoupling by cessation of turbulence in the stable MBL. The O3 mixing ratio in the NYC urban plumes remained at 80–90 ppbv during nocturnal transport over the stable MBL, then grew to over 100 ppbv by daytime oxidation of nitrogen oxides (NOx = NO + NO2 with mixing ratios on the order of 1 ppbv. Efficient transport of reactive nitrogen species (NOy, specifically nitric

  18. The development of an ecological approach to manage the pollution risk from highway runoff.

    Science.gov (United States)

    Crabtree, B; Dempsey, P; Johnson, I; Whitehead, M

    2009-01-01

    In the UK, the Highways Agency is responsible for operating, maintaining and improving the strategic road network in England. One focus of the Highways Agency's ongoing research into the nature and impact of highway runoff is aimed at ensuring that the Highways Agency will meet the requirements of the EU Water Framework Directive. A research programme, undertaken in partnership with the Environment Agency, is in progress to develop a better understanding of pollutants in highway runoff and their ecological impact. The paper presents the outcome of a study to: (1) monitor pollutants in highway runoff under different climate and traffic conditions; (2) develop standards to assess potential ecological risks from soluble pollutants in highway runoff; and (3) develop a model to predict pollutant concentrations in highway runoff. The model has been embedded in a design tool incorporating risk assessment procedures and receiving water standards for soluble and insoluble pollutants--the latter has been developed elsewhere in another project within the research programme. The design tool will be used to support improved guidance on where, and to what level, treatment of runoff is required for highway designers to manage the risk of ecological impact from highway runoff.

  19. Nighttime NOx Chemistry in Coal-Fired Power Plant Plumes

    Science.gov (United States)

    Fibiger, D. L.; McDuffie, E. E.; Dube, W. P.; Veres, P. R.; Lopez-Hilfiker, F.; Lee, B. H.; Green, J. R.; Fiddler, M. N.; Ebben, C. J.; Sparks, T.; Weinheimer, A. J.; Montzka, D.; Campos, T. L.; Cohen, R. C.; Bililign, S.; Holloway, J. S.; Thornton, J. A.; Brown, S. S.

    2015-12-01

    Nitrogen oxides (NOx = NO + NO2) play a key role in atmospheric chemistry. During the day, they catalyze ozone (O3) production, while at night they can react to form nitric acid (HNO3) and nitryl chloride (ClNO2) and remove O3 from the atmosphere. These processes are well studied in the summer, but winter measurements are more limited. Coal-fired power plants are a major source of NOx to the atmosphere, making up approximately 30% of emissions in the US (epa.gov). NOx emissions can vary seasonally, as well as plant-to-plant, with important impacts on the details of the plume chemistry. In particular, due to inefficient plume dispersion, nighttime NOx emissions from power plants are held in concentrated plumes, where rates of mixing with ambient O3 have a strong influence on plume evolution. We will show results from the aircraft-based WINTER campaign over the northeastern United States, where several nighttime intercepts of power plant plumes were made. Several of these intercepts show complete O3 titration, which can have a large influence on NOx lifetime, and thus O3 production, in the plume. When power plant NO emissions exceed background O3 levels, O3 is completely consumed converting NO to NO2. In the presence of O3, NO2 will be oxidized to NO3, which will then react with NO2 to form N2O5, which can then form HNO3 and/or ClNO2 and, ultimately, remove NOx from the atmosphere or provide next-day oxidant sources. If there is no O3 present, however, no further chemistry can occur and NO and NO2 will be transported until mixing with sufficient O3 for higher oxidation products. Modeling results of plume development and mixing, which can tell us more about this transport, will also be presented.

  20. OClO and BrO observations in the volcanic plume of Mt. Etna - implications on the chemistry of chlorine and bromine species in volcanic plumes

    Science.gov (United States)

    Gliß, J.; Bobrowski, N.; Vogel, L.; Platt, U.

    2014-10-01

    Spatial and temporal profiles of chlorine dioxide (OClO), bromine monoxide (BrO) and sulphur dioxide (SO2) were measured in the plume of Mt. Etna, Italy, in September 2012 using Multi-Axis-Differential-Optical-Absorption-Spectroscopy (MAX-DOAS). OClO (BrO) was detected in 119 (452) individual measurements covering plume ages up to 6 (23) minutes. The retrieved slant column densities (SCDs) reached values up to 2.0 × 1014 molecules cm-2 (OClO) and 1.1 × 1015 molecules cm-2 (BrO). In addition, the spectra were analysed for signatures of IO, OIO and OBrO, none of these species could be detected. The corresponding detection limits for IO / SO2, OIO / SO2 and OBrO / SO2 were 1.8 × 10-6, 2.0 × 10-5 and 1.1 × 10-5 respectively. The measurements were performed at plume ages (τ) from zero to 23 min downwind the emission source. The chemical variability of BrO and OClO in the plume was studied analysing the OClO / SO2 and BrO / SO2-ratio. A marked increase of both ratios was observed in the young plume (τ 3 min) with mean abundances of 3.17 × 10-5 (OClO / SO2), 1.55 × 10-4 (BrO / SO2) and 0.16 (OClO / BrO). Furthermore, enhanced BrO/SO2-ratios were found at the plume edges (by ~30-37%) and a strong indication of enhanced OClO / SO2-ratios as well (~10-250%). A measurement performed in the early morning (05:20-06:20 UTC, sunrise: 04:40 UTC) showed an BrO / SO2-ratio increasing with time until 05:35 UTC and a constant ratio afterwards. Observing this increase was only possible due to a correction for stratospheric BrO signals in the plume spectra. The corresponding OClO / SO2-ratio showed a similar trend stabilising around 06:13 UTC, approximately 40 min later than BrO. This is another strong indication for the photochemical nature of the reactions involved in the formation of oxidised halogens in volcanic plumes. In particular, these findings support the current understanding of the underlying chemistry, namely, that BrO is formed in an autocatalytic reaction

  1. Mobile Bay turbidity plume study

    Science.gov (United States)

    Crozier, G. F.

    1976-01-01

    Laboratory and field transmissometer studies on the effect of suspended particulate material upon the appearance of water are reported. Quantitative correlations were developed between remotely sensed image density, optical sea truth data, and actual sediment load. Evaluation of satellite image sea truth data for an offshore plume projects contours of transmissivity for two different tidal phases. Data clearly demonstrate the speed of change and movement of the optical plume for water patterns associated with the mouth of Mobile bay in which relatively clear Gulf of Mexico water enters the bay on the eastern side. Data show that wind stress in excess of 15 knots has a marked impact in producing suspended sediment loads.

  2. Sewage outfall plume dispersion observations with an autonomous underwater vehicle.

    Science.gov (United States)

    Ramos, P; Cunha, S R; Neves, M V; Pereira, F L; Quintaneiro, I

    2005-01-01

    This work represents one of the first successful applications of Autonomous Underwater Vehicles (AUVs) for interdisciplinary coastal research. A monitoring mission to study the shape and estimate the initial dilution of the S. Jacinto sewage outfall plume using an AUV was performed on July 2002. An efficient sampling strategy enabling greater improvements in spatial and temporal range of detection demonstrated that the sewage effluent plume can be clearly traced using naturally occurring tracers in the wastewater. The outfall plume was found at the surface highly influenced by the weak stratification and low currents. Dilution varying with distance downstream was estimated from the plume rise over the outfall diffuser until a nearly constant value of 130:1, 60 m from the diffuser, indicating the near field end. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a very effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated.

  3. The Multimedia Environmental Pollutant Assessment System (MEPAS)reg-sign: Atmospheric pathway formulations. Revision

    International Nuclear Information System (INIS)

    Droppo, J.G.; Buck, J.W.

    1996-03-01

    The Multimedia Environmental Pollutant Assessment System (MEPAS) is an integrated software implementation of physics-based fate and transport models for health and environmental risk assessments of both radioactive and hazardous pollutants. This atmospheric component report is one of a series of formulation reports that document the MEPAS mathematical models. MEPAS is a multimedia model; pollutant transport is modeled within, through, and between multiple media (air, soil, groundwater, and surface water). The estimated concentrations in the various media are used to compute exposures and impacts to the environment, to maximum individuals, and to populations. The MEPAS atmospheric component for the air media documented in this report includes models for emission from a source to the air, initial plume rise and dispersion, airborne pollutant transport and dispersion, and deposition to soils and crops. The material in this report is documentation for MEPAS Versions 3.0 and 3.1 and the MEPAS version used in the Remedial Action Assessment System (RAAS) Version 1.0

  4. Radiatively-driven processes in forest fire and desert dust plumes

    Energy Technology Data Exchange (ETDEWEB)

    Weinzierl, Bernadett Barbara

    2008-07-01

    The absorption of solar radiation by atmospheric aerosol particles is important for the climate effects of aerosols. Absorption by aerosol particles heats atmospheric layers, even though the net effect for the entire atmospheric column may still be a cooling. Most experimental studies on absorbing aerosols so far focussed mainly on the aerosol properties and did not consider the influence of the aerosols on the thermodynamic structure of the atmosphere. In this study, data from two international aircraft field experiments, the Intercontinental Transport of Ozone and Precursors study (ITOP) 2004 and the Saharan Mineral Dust Experiment (SAMUM) 2006 are investigated. The ITOP data were collected before the work on this thesis started, while the logistics and the instrument preparation of the SAMUM campaign, the weather forecast during SAMUM and the in-situ aerosol measurements during SAMUM were done within this thesis. The experimental data are used to explore the impact of layers containing absorbing forest fire and desert dust aerosol particles on the atmospheric stability and the implications of a changed stability on the development of the aerosol microphysical and optical properties during long-range transport. For the first time, vertical profiles of the Richardson number Ri are used to assess the stability and mixing in forest fire and desert dust plumes. Also for the first time, the conclusions drawn from the observations of forest fire and desert dust aerosol, at first glance apparently quite different aerosol types, are discussed from a common perspective. Two mechanisms, the selfstabilising and the sealed ageing effect, acting in both forest fire and desert dust aerosol layers, are proposed to explain the characteristic temperature structure as well as the aerosol properties observed in lofted forest fire and desert dust plumes. The proposed effects impact on the ageing of particles within the plumes and reduce the plume dilution, therefore extending the

  5. Spectrum Diagnosis for Fuchsia Plume of Hall Effect Thruster with Xenon as Propellant

    International Nuclear Information System (INIS)

    Yu Daren; Ding Jiapeng; Dai Jingmin

    2006-01-01

    The colour of the Hall effect thruster's plume is often light-green, and sometimes a fuchsia plume appears during experiments. Based on a spectrum and colour analysis, and a comparison with normal plumes, a conclusion is made that the density of the Xe ions and the temperature of electrons are low when the plume appears fuchsia. In this condition, most of the components of the plume are Xe atoms, and the ionization rate of the propellant is low

  6. The immobilisation and retention of soluble arsenic, cadmium and zinc by biochar

    International Nuclear Information System (INIS)

    Beesley, Luke; Marmiroli, Marta

    2011-01-01

    Water-soluble inorganic pollutants may constitute an environmental toxicity problem if their movement through soils and potential transfer to plants or groundwater is not arrested. The capability of biochar to immobilise and retain arsenic (As), cadmium (Cd) and zinc (Zn) from a multi-element contaminated sediment-derived soil was explored by a column leaching experiment and scanning electron microanalysis (SEM/EDX). Sorption of Cd and Zn to biochar's surfaces assisted a 300 and 45-fold reduction in their leachate concentrations, respectively. Retention of both metals was not affected by considerable leaching of water-soluble carbon from biochar, and could not be reversed following subsequent leaching of the sorbant biochar with water at pH 5.5. Weakly water-soluble As was also retained on biochar's surface but leachate concentrations did not duly decline. It is concluded that biochar can rapidly reduce the mobility of selected contaminants in this polluted soil system, with especially encouraging results for Cd. - Research highlights: → The capability of biochar to immobilise and retain arsenic (As), cadmium (Cd) and zinc (Zn) from a multi-element contaminated sediment-derived soil was explored by a column leaching experiment and scanning electron microanalysis (SEM/EDX). We highlight the following results from this study: → Large surface area and surface sorption of Cd and Zn to biochar reduces the concentrations of these metals in leachates from a contaminated soil 300 and 45-fold respectively. → Metal retention was not reversible by continued leaching of the sorbant biochar. → Biochar increased leachate pH and water-soluble carbon but this did not appear to be detrimental to its effects and may aid retention of Cd. → Although some arsenic was sorbed to biochar, leachate concentrations were not duly reduced. → Developments in micro-analyses techniques will allow more detailed exploration of the encouraging results seen here with regards to interior

  7. Vegetation fires, absorbing aerosols and smoke plume characteristics in diverse biomass burning regions of Asia

    International Nuclear Information System (INIS)

    Vadrevu, Krishna Prasad; Lasko, Kristofer; Giglio, Louis; Justice, Chris

    2015-01-01

    In this study, we explored the relationships between the satellite-retrieved fire counts (FC), fire radiative power (FRP) and aerosol indices using multi-satellite datasets at a daily time-step covering ten different biomass burning regions in Asia. We first assessed the variations in MODIS-retrieved aerosol optical depths (AOD’s) in agriculture, forests, plantation and peat land burning regions and then used MODIS FC and FRP (hereafter FC/FRP) to explain the variations in AOD characteristics. Results suggest that tropical broadleaf forests in Laos burn more intensively than the other vegetation fires. FC/FRP-AOD correlations in different agricultural residue burning regions did not exceed 20% whereas in forest regions they reached 40%. To specifically account for absorbing aerosols, we used Ozone Monitoring Instrument-derived aerosol absorption optical depth (AAOD) and UV aerosol index (UVAI). Results suggest relatively high AAOD and UVAI values in forest fires compared with peat and agriculture fires. Further, FC/FRP could explain a maximum of 29% and 53% of AAOD variations, whereas FC/FRP could explain at most 33% and 51% of the variation in agricultural and forest biomass burning regions, respectively. Relatively, UVAI was found to be a better indicator than AOD and AAOD in both agriculture and forest biomass burning plumes. Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations data showed vertically elevated aerosol profiles greater than 3.2–5.3 km altitude in the forest fire plumes compared to 2.2–3.9 km and less than 1 km in agriculture and peat-land fires, respectively. We infer the need to assimilate smoke plume height information for effective characterization of pollutants from different sources. (letter)

  8. Response of mantle transition zone thickness to plume buoyancy flux

    Science.gov (United States)

    Das Sharma, S.; Ramesh, D. S.; Li, X.; Yuan, X.; Sreenivas, B.; Kind, R.

    2010-01-01

    The debate concerning thermal plumes in the Earth's mantle, their geophysical detection and depth characterization remains contentious. Available geophysical, petrological and geochemical evidence is at variance regarding the very existence of mantle plumes. Utilizing P-to-S converted seismic waves (P receiver functions) from the 410 and 660 km discontinuities, we investigate disposition of these boundaries beneath a number of prominent hotspot regions. The thickness of the mantle transition zone (MTZ), measured as P660s-P410s differential times (tMTZ), is determined. Our analyses suggest that the MTZ thickness beneath some hotspots correlates with the plume strength. The relationship between tMTZ, in response to the thermal perturbation, and the strength of plumes, as buoyancy flux B, follows a power law. This B-tMTZ behavior provides unprecedented insights into the relation of buoyancy flux and excess temperature at 410-660 km depth below hotspots. We find that the strongest hotspots, which are located in the Pacific, are indeed plumes originating at the MTZ or deeper. According to the detected power law, even the strongest plumes may not shrink the transition zone by significantly more than ~40 km (corresponding to a maximum of 300-400° excess temperature).

  9. The Green Ocean Amazon Experiment (GoAmazon2014/5) Observes Pollution Affecting Gases, Aerosols, Clouds, and Rainfall over the Rain Forest

    Energy Technology Data Exchange (ETDEWEB)

    Martin, S. T. [Harvard University, Cambridge, Massachusetts; Artaxo, P. [University of São Paulo, São Paulo, Brazil; Machado, L. [National Institute for Space Research, São José dos Campos, Brazil; Manzi, A. O. [National Institute of Amazonian Research, Manaus, Amazonas, Brazil; Souza, R. A. F. [Amazonas State University, Amazonas, Brazil; Schumacher, C. [Texas A& amp,M University, College Station, Texas; Wang, J. [Brookhaven National Laboratory, Upton, New York; Biscaro, T. [National Institute for Space Research, São José dos Campos, Brazil; Brito, J. [University of São Paulo, São Paulo, Brazil; Calheiros, A. [National Institute for Space Research, São José dos Campos, Brazil; Jardine, K. [Lawrence Berkeley National Lab, Berkeley, California; Medeiros, A. [Amazonas State University, Amazonas, Brazil; Portela, B. [National Institute of Amazonian Research, Manaus, Amazonas, Brazil; de Sá, S. S. [Harvard University, Cambridge, Massachusetts; Adachi, K. [Meteorological Research Institute, Tsukuba, Ibaraki, Japan; Aiken, A. C. [Los Alamos National Laboratory, Los Alamos, New Mexico; Albrecht, R. [University of São Paulo, São Paulo, Brazil; Alexander, L. [Pacific Northwest National Laboratory, Richland, Washington; Andreae, M. O. [Max Planck Institute for Chemistry, Mainz, Germany; Barbosa, H. M. J. [University of São Paulo, São Paulo, Brazil; Buseck, P. [Arizona State University, Tempe, Arizona; Chand, D. [Pacific Northwest National Laboratory, Richland, Washington; Comstock, J. M. [Pacific Northwest National Laboratory, Richland, Washington; Day, D. A. [University of Colorado Boulder, Boulder, Colorado; Dubey, M. [Los Alamos National Laboratory, Los Alamos, New Mexico; Fan, J. [Pacific Northwest National Laboratory, Richland, Washington; Fast, J. [Pacific Northwest National Laboratory, Richland, Washington; Fisch, G. [Aeronautic and Space Institute, São José dos Campos, Brazil; Fortner, E. [Aerodyne, Inc., Billerica, Massachusetts; Giangrande, S. [Brookhaven National Laboratory, Upton, New York; Gilles, M. [Lawrence Berkeley National Lab, Berkeley, California; Goldstein, A. H. [University of California, Berkeley, Berkeley, California; Guenther, A. [University of California, Irvine, Irvine, California; Hubbe, J. [Pacific Northwest National Laboratory, Richland, Washington; Jensen, M. [Brookhaven National Laboratory, Upton, New York; Jimenez, J. L. [University of Colorado Boulder, Boulder, Colorado; Keutsch, F. N. [Harvard University, Cambridge, Massachusetts; Kim, S. [University of California, Irvine, Irvine, California; Kuang, C. [Brookhaven National Laboratory, Upton, New York; Laskin, A. [Pacific Northwest National Laboratory, Richland, Washington; McKinney, K. [Harvard University, Cambridge, Massachusetts; Mei, F. [Pacific Northwest National Laboratory, Richland, Washington; Miller, M. [Rutgers, The State University of New Jersey, New Brunswick, New Jersey; Nascimento, R. [Amazonas State University, Amazonas, Brazil; Pauliquevis, T. [Federal University of São Paulo, São Paulo, Brazil; Pekour, M. [Pacific Northwest National Laboratory, Richland, Washington; Peres, J. [University of São Paulo, São Paulo, Brazil; Petäjä, T. [University of Helsinki, Helsinki, Finland; Pöhlker, C. [Max Planck Institute for Chemistry, Mainz, Germany; Pöschl, U. [Max Planck Institute for Chemistry, Mainz, Germany; Rizzo, L. [Federal University of São Paulo, São Paulo, Brazil; Schmid, B. [Pacific Northwest National Laboratory, Richland, Washington; Shilling, J. E. [Pacific Northwest National Laboratory, Richland, Washington; Dias, M. A. Silva [University of São Paulo, São Paulo, Brazil; Smith, J. N. [University of California, Irvine, Irvine, California; Tomlinson, J. M. [Pacific Northwest National Laboratory, Richland, Washington; Tóta, J. [Federal University of West Para, Santarém, Pará, Brazil; Wendisch, M. [University of Leipzig, Leipzig, Germany

    2017-05-01

    The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) experiment took place around the urban region of Manaus in central Amazonia across two years. The urban pollution plume was used to study the susceptibility of gases, aerosols, clouds, and rainfall to human activities in a tropical environment. Many aspects of air quality, weather, terrestrial ecosystems, and climate work differently in the tropics than in the more thoroughly studied USA, employed an unparalleled suite of measurements at nine ground sites and onboard two aircraft to investigate the flow of background air into Manaus, the emissions into the air over the city, and the advection of the pollution downwind of the city. Herein, to visualize this train of processes and its effects, observations aboard a low-flying aircraft are presented. Comparative measurements within and adjacent to the plume followed the emissions of biogenic volatile organic carbon compounds (BVOCs) from the tropical forest, their transformations by the atmospheric oxidant cycle, alterations of this cycle by the influence of the pollutants, transformations of the chemical products into aerosol particles, the relationship of these particles to cloud condensation nuclei (CCN) activity, and the differences in cloud properties and rainfall for background compared to polluted conditions. The observations of the GoAmazon2014/5 experiment illustrate how the hydrologic cycle, radiation balance, and carbon recycling may be affected by present-day as well as future economic development and pollution over the Amazonian tropical forest.

  10. The mantle-plume model, its feasibility and consequences

    NARCIS (Netherlands)

    Calsteren, van P.W.C.

    1981-01-01

    High beat-flow foci on the Earth have been named ‘hot-spots’ and are commonly correlated with ‘mantle-plumes’ in the deep. A mantle plume may be described as a portion of mantle material with a higher heat content than its surroundings. The intrusion of a mantle-plume is inferred to be similar to

  11. CFD investigation of balcony spill plumes in atria

    International Nuclear Information System (INIS)

    McCartney, C.J.; Lougheed, G.D.; Weckman, E.J.

    2004-01-01

    Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production rate of the buoyant fire plume. One design issue is the smoke production rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes are based on a combination of one-tenth scale test data and theoretical analysis. Questions have arisen over the suitability of these correlations for real-scale designs. A combined program of full-scale experimentation and CFD modeling is being conducted to analyze the accuracy of these correlations. A full-scale experimental facility was constructed with a 5 m by 5 m by 15 m fire compartment connected to a four-story atrium. Propane fires in the compartment produce balcony spill plumes which form steady-state smoke layers in the atrium. Experimental variables include fire size, compartment opening width, balcony depth and compartment fascia depth. A variable exhaust system was used to achieve various smoke layer heights for each of 100 compartment configurations. Temperature, smoke obscuration and gas concentrations were measured in the compartment, atrium and exhaust system. The experimental data was used to determine the atrium smoke layer elevation and balcony spill plume smoke production rate for each configuration and fire size. Comparison of this data with zone model results and design correlations for atrium smoke management systems will be performed to evaluate their accuracy. A CFD model of the experimental facility was implemented using the Fire Dynamics Simulator software (Version 3). Large-eddy simulations of the flow were performed with a constant radiative fraction and an infinitely fast mixture fraction combustion model. A grid sensitivity analysis was

  12. Eyjafjallajokull Volcano Plume Particle-Type Characterization from Space-Based Multi-angle Imaging

    Science.gov (United States)

    Kahn, Ralph A.; Limbacher, James

    2012-01-01

    The Multi-angle Imaging SpectroRadiometer (MISR) Research Aerosol algorithm makes it possible to study individual aerosol plumes in considerable detail. From the MISR data for two optically thick, near-source plumes from the spring 2010 eruption of the Eyjafjallaj kull volcano, we map aerosol optical depth (AOD) gradients and changing aerosol particle types with this algorithm; several days downwind, we identify the occurrence of volcanic ash particles and retrieve AOD, demonstrating the extent and the limits of ash detection and mapping capability with the multi-angle, multi-spectral imaging data. Retrieved volcanic plume AOD and particle microphysical properties are distinct from background values near-source, as well as for overwater cases several days downwind. The results also provide some indication that as they evolve, plume particles brighten, and average particle size decreases. Such detailed mapping offers context for suborbital plume observations having much more limited sampling. The MISR Standard aerosol product identified similar trends in plume properties as the Research algorithm, though with much smaller differences compared to background, and it does not resolve plume structure. Better optical analogs of non-spherical volcanic ash, and coincident suborbital data to validate the satellite retrieval results, are the factors most important for further advancing the remote sensing of volcanic ash plumes from space.

  13. Plume Particle Collection and Sizing from Static Firing of Solid Rocket Motors

    Science.gov (United States)

    Sambamurthi, Jay K.

    1995-01-01

    Thermal radiation from the plume of any solid rocket motor, containing aluminum as one of the propellant ingredients, is mainly from the microscopic, hot aluminum oxide particles in the plume. The plume radiation to the base components of the flight vehicle is primarily determined by the plume flowfield properties, the size distribution of the plume particles, and their optical properties. The optimum design of a vehicle base thermal protection system is dependent on the ability to accurately predict this intense thermal radiation using validated theoretical models. This article describes a successful effort to collect reasonably clean plume particle samples from the static firing of the flight simulation motor (FSM-4) on March 10, 1994 at the T-24 test bed at the Thiokol space operations facility as well as three 18.3% scaled MNASA motors tested at NASA/MSFC. Prior attempts to collect plume particles from the full-scale motor firings have been unsuccessful due to the extremely hostile thermal and acoustic environment in the vicinity of the motor nozzle.

  14. The effect of sediments on turbulent plume dynamics in a stratified fluid

    Science.gov (United States)

    Stenberg, Erik; Ezhova, Ekaterina; Brandt, Luca

    2017-11-01

    We report large eddy simulation results of sediment-loaded turbulent plumes in a stratified fluid. The configuration, where the plume is discharged from a round source, provides an idealized model of subglacial discharge from a submarine tidewater glacier and is a starting point for understanding the effect of sediments on the dynamics of the rising plume. The transport of sediments is modeled by means of an advection-diffusion equation where sediment settling velocity is taken into account. We initially follow the experimental setup of Sutherland (Phys. Rev. Fluids, 2016), considering uniformly stratified ambients and further extend the work to pycnocline-type stratifications typical of Greenland fjords. Apart from examining the rise height, radial spread and intrusion of the rising plume, we gain further insights of the plume dynamics by extracting turbulent characteristics and the distribution of the sediments inside the plume.

  15. Comparative cytotoxicity and genotoxicity of soluble and particulate hexavalent chromium in human and hawksbill sea turtle (Eretmochelys imbricate) skin cells

    Science.gov (United States)

    Young, Jamie L.; Wise, Sandra S.; Xie, Hong; Zhu, Cairong; Fukuda, Tomokazu; Wise, John Pierce

    2015-01-01

    Chromium is both a global marine pollutant and a known human health hazard. In this study, we compare the cytotoxicity and genotoxicity of both soluble and particulate chromate in human and hawksbill sea turtle (Eretmochelys imbricata) skin fibroblasts. Our data show that both soluble and particulate Cr(VI) induce concentration-dependent increases in cytotoxicity, genotoxicity, and intracellular Cr ion concentrations in both human and hawksbill sea turtle fibroblasts. Based on administered concentration, particulate and soluble Cr(VI) were more cytotoxic and clastogenic to human cells than sea turtle cells. When the analysis was based on the intracellular concentration of Cr, the data showed the response of both species was similar. The one exception was the cytotoxicity of intracellular Cr ions from soluble Cr(VI), which caused more cytotoxicity in sea turtle cells (LC50=271 uM) that human cells (LC50=471 uM), but its clastogenicity was similar between the two species. Thus, adjusting for differences in uptake indicated the explanation for the difference in potency was mostly due to uptake rather than differently affected mechanisms. Overall these data indicate sea turtles may be a useful sentinel for human health responses to marine pollution. PMID:26440299

  16. Tidally induced lateral dispersion of the Storfjorden overflow plume

    Directory of Open Access Journals (Sweden)

    F. Wobus

    2013-10-01

    Full Text Available We investigate the flow of brine-enriched shelf water from Storfjorden (Svalbard into Fram Strait and onto the western Svalbard Shelf using a regional set-up of NEMO-SHELF, a 3-D numerical ocean circulation model. The model is set up with realistic bathymetry, atmospheric forcing, open boundary conditions and tides. The model has 3 km horizontal resolution and 50 vertical levels in the sh-coordinate system which is specially designed to resolve bottom boundary layer processes. In a series of modelling experiments we focus on the influence of tides on the propagation of the dense water plume by comparing results from tidal and non-tidal model runs. Comparisons of non-tidal to tidal simulations reveal a hotspot of tidally induced horizontal diffusion leading to the lateral dispersion of the plume at the southernmost headland of Spitsbergen which is in close proximity to the plume path. As a result the lighter fractions in the diluted upper layer of the plume are drawn into the shallow coastal current that carries Storfjorden water onto the western Svalbard Shelf, while the dense bottom layer continues to sink down the slope. This bifurcation of the plume into a diluted shelf branch and a dense downslope branch is enhanced by tidally induced shear dispersion at the headland. Tidal effects at the headland are shown to cause a net reduction in the downslope flux of Storfjorden water into the deep Fram Strait. This finding contrasts previous results from observations of a dense plume on a different shelf without abrupt topography.

  17. Plasma plume expansion dynamics in nanosecond Nd:YAG laserosteotome

    Science.gov (United States)

    Abbasi, Hamed; Rauter, Georg; Guzman, Raphael; Cattin, Philippe C.; Zam, Azhar

    2018-02-01

    In minimal invasive laser osteotomy precise information about the ablation process can be obtained with LIBS in order to avoid carbonization, or cutting of wrong types of tissue. Therefore, the collecting fiber for LIBS needs to be optimally placed in narrow cavities in the endoscope. To determine this optimal placement, the plasma plume expansion dynamics in ablation of bone tissue by the second harmonic of a nanosecond Nd:YAG laser at 532 nm has been studied. The laserinduced plasma plume was monitored in different time delays, from one nanosecond up to one hundred microseconds. Measurements were performed using high-speed gated illumination imaging. The expansion features were studied using illumination of the overall visible emission by using a gated intensified charged coupled device (ICCD). The camera was capable of having a minimum gate width (Optical FWHM) of 3 ns and the timing resolution (minimum temporal shift of the gate) of 10 ps. The imaging data were used to generate position-time data of the luminous plasma-front. Moreover, the velocity of the plasma plume expansion was studied based on the time-resolved intensity data. By knowing the plasma plume profile over time, the optimum position (axial distance from the laser spot) of the collecting fiber and optimal time delay (to have the best signal to noise ratio) in spatial-resolved and time-resolved laser-induced breakdown spectroscopy (LIBS) can be determined. Additionally, the function of plasma plume expansion could be used to study the shock wave of the plasma plume.

  18. Geochemical modeling of leaching from MSWI air-pollution control residues

    NARCIS (Netherlands)

    Astrup, T.; Dijkstra, J.J.; Comans, R.N.J.; Sloot, van der H.A.; Christensen, T.H.

    2006-01-01

    This paper provides an improved understanding of the leaching behavior of waste incineration air-pollution-control (APC) residues in a long-term perspective. Leaching was investigated by a series of batch experiments reflecting leaching conditions after initial washout of highly soluble salts from

  19. Signal information available for plume source tracking with and without surface waves and learning by undergraduates assisting with the research

    Science.gov (United States)

    Wiley, Megan Beth

    Autonomous vehicles have had limited success in locating point sources of pollutants, chemicals, and other passive scalars. However, animals such as stomatopods, a mantis shrimp, track odor plumes easily for food, mates, and habitat. Laboratory experiments using Planar Laser Induced Fluorescence measured odor concentration downstream of a diffusive source with and without live stomatopods to investigate their source-tracking strategies in unidirectional and "wave-affected" (surface waves with a mean current) flows. Despite the dearth of signal, extreme temporal variation, and meandering plume centerline, the stomatopods were able to locate the source, especially in the wave-affected flow. Differences in the two plumes far from the source (>160 cm) appeared to help the animals in the wave-affected flow position themselves closer to the source (fluid mechanics, and there was little evidence of learning by participation in the RAship. One RA's conceptions of turbulence did change, but a group workshop seemed to support this learning more than the RAship. The documented conceptions could aid in curriculum design, since situating new information within current knowledge seems to deepen learning outcomes. The RAs' conceptions varied widely with some overlap of ideas. The interviews also showed that most RAs did not discuss molecular diffusion as part of the mixing process and some remembered information from course demonstrations, but applied them inappropriately to the interview questions.

  20. Computer Simulation for Dispersion of Air Pollution Released from a Line Source According to Gaussian Model

    International Nuclear Information System (INIS)

    Emad, A.A.; El Shazly, S.M.; Kassem, Kh.O.

    2010-01-01

    A line source model, developed in laboratory of environmental physics, faculty of science at Qena, Egypt is proposed to describe the downwind dispersion of pollutants near roadways, at different cities in Egypt. The model is based on the Gaussian plume methodology and is used to predict air pollutants' concentrations near roadways. In this direction, simple software has been presented in this paper, developed by authors, adopted completely Graphical User Interface (GUI) technique for operating in various windows-based microcomputers. The software interface and code have been designed by Microsoft Visual basic 6.0 based on the Gaussian diffusion equation. This software is developed to predict concentrations of gaseous pollutants (eg. CO, SO 2 , NO 2 and particulates) at a user specified receptor grid

  1. Smoke plume trajectory from in-situ burning of crude oil: complex terrain modeling

    International Nuclear Information System (INIS)

    McGrattan, K.

    1997-01-01

    Numerical models have been used to predict the concentration of particulate matter or other combustion products downwind from a proposed in- situ burning of an oil spill. One of the models used was the National Institute of Standards and Technology (NIST) model, ALOFT (A Large Outdoor Fire plume Trajectory), which is based on the conservation equations that govern the introduction of hot gases and particulate matter into the atmosphere. By using a model based on fundamental equations, it becomes a relatively simple matter to simulate smoke dispersal flow patterns, and to compute the solution to the equations of motion that govern the transport of pollutants in the lower atmosphere at a resolution that is comparable to that of the underlying terrain data. 9 refs., 2 tabs., 5 figs

  2. Novel plume deflection concept testing

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will explore the feasibility and effectiveness of utilizing an electrically driven thermal shield for use as part of rocket plume deflectors. To...

  3. Waves generated in the plasma plume of helicon magnetic nozzle

    International Nuclear Information System (INIS)

    Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen

    2013-01-01

    Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of the plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.

  4. A cold plasma plume with a highly conductive liquid electrode

    International Nuclear Information System (INIS)

    Chen Guangliang; Chen Wenxing; Chen Shihua; Yang Size

    2008-01-01

    A cold dielectric barrier discharge (DBD) plasma plume with one highly conductive liquid electrode has been developed to treat thermally sensitive materials, and its preliminary discharging characteristics have been studied. The averaged electron temperature and density is estimated to be 0.6eV and 10 11 /cm 3 , respectively. The length of plasma plume can reach 5 cm with helium gas (He), and the conductivity of the outer electrode affects the plume length obviously. This plasma plume could be touched by bare hand without causing any burning or painful sensation, which may provide potential application for safe aseptic skin care. Moreover, the oxidative particles (e.g., OH, O * , O 3 ) in the downstream oxygen (O2) gas of the plume have been applied to treat the landfill leachate. The results show that the activated O 2 gas can degrade the landfill leachate effectively, and the chemical oxygen demand (COD), conductivity, biochemical oxygen demand (BOD), and suspended solid (SS) can be decreased by 52%, 57%, 76% and 92%, respectively. (fluids, plasmas and electric discharges)

  5. Waves generated in the plasma plume of helicon magnetic nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Nagendra; Rao, Sathyanarayan; Ranganath, Praveen [Department of Electrical and Computer Engineering, University of Alabama, Huntsville, Alabama 35899 (United States)

    2013-03-15

    Experimental measurements have shown that the plasma plume created in a helicon plasma device contains a conical structure in the plasma density and a U-shaped double layer (US-DL) tightly confined near the throat where plasma begins to expand from the source. Recently reported two-dimensional particle-in-cell simulations verified these density and US-DL features of the plasma plume. Simulations also showed that the plasma in the plume develops non-thermal feature consisting of radial ion beams with large densities near the conical surface of the density structure. The plasma waves that are generated by the radial ion beams affecting the structure of the plasma plume are studied here. We find that most intense waves persist in the high-density regions of the conical density structure, where the transversely accelerated ions in the radial electric fields in the plume are reflected setting up counter-streaming. The waves generated are primarily ion Bernstein modes. The nonlinear evolution of the waves leads to magnetic field-aligned striations in the fields and the plasma near the conical surface of the density structure.

  6. Jet plume injection and combustion system for internal combustion engines

    Science.gov (United States)

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

    1993-01-01

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  7. A plume-in-grid approach to characterize air quality impacts of aircraft emissions at the Hartsfield–Jackson Atlanta International Airport

    Directory of Open Access Journals (Sweden)

    J. Rissman

    2013-09-01

    Full Text Available This study examined the impacts of aircraft emissions during the landing and takeoff cycle on PM2.5 concentrations during the months of June and July 2002 at the Hartsfield–Jackson Atlanta International Airport. Primary and secondary pollutants were modeled using the Advanced Modeling System for Transport, Emissions, Reactions, and Deposition of Atmospheric Matter (AMSTERDAM. AMSTERDAM is a modified version of the Community Multiscale Air Quality (CMAQ model that incorporates a plume-in-grid process to simulate emissions sources of interest at a finer scale than can be achieved using CMAQ's model grid. Three fundamental issues were investigated: the effects of aircraft on PM2.5 concentrations throughout northern Georgia, the differences resulting from use of AMSTERDAM's plume-in-grid process rather than a traditional CMAQ simulation, and the concentrations observed in aircraft plumes at subgrid scales. Comparison of model results with an air quality monitor located in the vicinity of the airport found that normalized mean bias ranges from −77.5% to 6.2% and normalized mean error ranges from 40.4% to 77.5%, varying by species. Aircraft influence average PM2.5 concentrations by up to 0.232 μg m−3 near the airport and by 0.001–0.007 μg m−3 throughout the Atlanta metro area. The plume-in-grid process increases concentrations of secondary PM pollutants by 0.005–0.020 μg m−3 (compared to the traditional grid-based treatment but reduces the concentration of non-reactive primary PM pollutants by up to 0.010 μg m−3, with changes concentrated near the airport. Examination of subgrid-scale results indicates that median aircraft contribution to grid cells is higher than median puff concentration in the airport's grid cell and outside of a 20 km × 20 km square area centered on the airport, while in a 12 km × 12 km square ring centered on the airport, puffs have median concentrations over an order of magnitude higher than aircraft

  8. Plume dynamics in TiC laser ablation

    International Nuclear Information System (INIS)

    D'Alessio, L.; Galasso, A.; Santagata, A.; Teghil, R.; Villani, A.R.; Villani, P.; Zaccagnino, M.

    2003-01-01

    In this work, the analysis of the gaseous phase, produced by pulsed laser ablation of a TiC target and performed by emission spectroscopy and intensified charge coupled device (ICCD) imaging is reported. In the case of laser fluence higher than 3 J/cm 2 , the front of the emitting plume is identified with the presence of Ti 2+ ions, while the presence of a double maximum is due to the neutral and ionized titanium particles traveling with different velocities. At a laser fluence lower than 3 J/cm 2 , the front is marked by C + emission and only one maximum is present. The results, compared with those obtained for other carbides of group 4, evidence that only in the plume produced from TiC targets there is the presence of a large amount of ions with high kinetic energy. In particular, the highly energetic M 2+ ions (M=Ti, Zr, Hf) are present only in the TiC plume. The different energy and concentration of ions in the different carbide plumes confirm the importance of the ionized part of the gaseous phase in the film growth mechanism. In fact only in the TiC films, we find a layered structure in contrast with the columnar structure found in the other carbides of the same group

  9. Critical Magnetic Field Strengths for Unipolar Solar Coronal Plumes In Quiet Regions and Coronal Holes?

    Science.gov (United States)

    Avallone, Ellis; Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L.; Winebarger, Amy

    2017-01-01

    Coronal plumes are bright magnetic funnels that are found in quiet regions and coronal holes that extend high into the solar corona whose lifetimes can last from hours to days. The heating processes that make plumes bright involve the magnetic field at the base of the plume, but their intricacies remain mysterious. Raouafi et al. (2014) infer from observation that plume heating is a consequence of magnetic reconnection at the base, whereas Wang et al. (2016) infer that plume heating is a result of convergence of the magnetic flux at the plume's base, or base flux. Both papers suggest that the base flux in their plumes is of mixed polarity, but do not quantitatively measure the base flux or consider whether a critical magnetic field strength is required for plume production. To investigate the magnetic origins of plume heating, we track plume luminosity in the 171 Å wavelength as well as the abundance and strength of the base flux over the lifetimes of six unipolar coronal plumes. Of these, three are in coronal holes and three are in quiet regions. For this sample, we find that plume heating is triggered when convergence of the base flux surpasses a field strength of approximately 300 - 500 Gauss, and that the luminosity of both quiet region and coronal hole plumes respond similarly to the strength of the magnetic field in the base.

  10. Smoke plumes from Kuwaiti oil fires as atmospheric experiment of opportunity: An early look. Final report, Mar-Oct 91

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, E.

    1991-10-01

    This document sets in context the smoke plume phenomenology associated with the large number of oil fires lit by the Iraqi military in Kuwait in February 1991, and which are probably the worst man-made air pollution event in human history. Based on the simple phenomenology given here, and considered an unfortunate 'experiment of opportunity', the question is raised of what actions should be taken, and what one can hope to learn from these events. From the standpoint of SDIO, most of the basic physical elements of the fire and smoke phenomenology appear to be understood although there are some new effects and the initial quantitative predictions of the experts appear to differ significantly from the results of the detailed measurements. Many observations have been made. They require analysis followed by review and publication before being incorporated in the DoD integrated phenomenology models. This document represents an early look at the smoke plumes before most of the observations have been analyzed, reviewed, and published; its main function is to raise questions that should be addressed more carefully later.

  11. Multiphase CFD modeling of nearfield fate of sediment plumes

    DEFF Research Database (Denmark)

    Saremi, Sina; Hjelmager Jensen, Jacob

    2014-01-01

    Disposal of dredged material and the overflow discharge during the dredging activities is a matter of concern due to the potential risks imposed by the plumes on surrounding marine environment. This gives rise to accurately prediction of the fate of the sediment plumes released in ambient waters...

  12. Contaminant plumes containment and remediation focus area. Technology summary

    International Nuclear Information System (INIS)

    1995-06-01

    EM has established a new approach to managing environmental technology research and development in critical areas of interest to DOE. The Contaminant Plumes Containment and Remediation (Plumes) Focus Area is one of five areas targeted to implement the new approach, actively involving representatives from basic research, technology implementation, and regulatory communities in setting objectives and evaluating results. This document presents an overview of current EM activities within the Plumes Focus Area to describe to the appropriate organizations the current thrust of the program and developing input for its future direction. The Plumes Focus Area is developing remediation technologies that address environmental problems associated with certain priority contaminants found at DOE sites, including radionuclides, heavy metals, and dense non-aqueous phase liquids (DNAPLs). Technologies for cleaning up contaminants of concern to both DOE and other federal agencies, such as volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and other organics and inorganic compounds, will be developed by leveraging resources in cooperation with industry and interagency programs

  13. Contaminant plumes containment and remediation focus area. Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    EM has established a new approach to managing environmental technology research and development in critical areas of interest to DOE. The Contaminant Plumes Containment and Remediation (Plumes) Focus Area is one of five areas targeted to implement the new approach, actively involving representatives from basic research, technology implementation, and regulatory communities in setting objectives and evaluating results. This document presents an overview of current EM activities within the Plumes Focus Area to describe to the appropriate organizations the current thrust of the program and developing input for its future direction. The Plumes Focus Area is developing remediation technologies that address environmental problems associated with certain priority contaminants found at DOE sites, including radionuclides, heavy metals, and dense non-aqueous phase liquids (DNAPLs). Technologies for cleaning up contaminants of concern to both DOE and other federal agencies, such as volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), and other organics and inorganic compounds, will be developed by leveraging resources in cooperation with industry and interagency programs.

  14. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection.

    Science.gov (United States)

    Álvarez-Romero, Jorge G; Pressey, Robert L; Ban, Natalie C; Brodie, Jon

    2015-01-01

    Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our

  15. Multiscale Approach to Small River Plumes off California

    Science.gov (United States)

    Basdurak, N. B.; Largier, J. L.; Nidzieko, N.

    2012-12-01

    While larger scale plumes have received significant attention, the dynamics of plumes associated with small rivers typical of California are little studied. Since small streams are not dominated by a momentum flux, their plumes are more susceptible to conditions in the coastal ocean such as wind and waves. In order to correctly model water transport at smaller scales, there is a need to capture larger scale processes. To do this, one-way nested grids with varying grid resolution (1 km and 10 m for the parent and the child grid respectively) were constructed. CENCOOS (Central and Northern California Ocean Observing System) model results were used as boundary conditions to the parent grid. Semi-idealized model results for Santa Rosa Creek, California are presented from an implementation of the Regional Ocean Modeling System (ROMS v3.0), a three-dimensional, free-surface, terrain-following numerical model. In these preliminary results, the interaction between tides, winds, and buoyancy forcing in plume dynamics is explored for scenarios including different strengths of freshwater flow with different modes (steady and pulsed). Seasonal changes in transport dynamics and dispersion patterns are analyzed.

  16. Quantifying mantle structure and dynamics using plume tracing in seismic tomography

    Science.gov (United States)

    O'Farrell, K. A.; Eakin, C. M.; Jackson, M. G.; Jones, T. D.; Lekic, V.; Lithgow-Bertelloni, C. R.

    2017-12-01

    Directly linking deep mantle processes with surface features and dynamics is a complex problem. Hotspot volcanism gives us surface observables of mantle signatures, but the depth and source of the mantle plumes feeding these hotspots are highly debated. To address these issues, it is necessary to consider the entire journey of a plume through the mantle. By analyzing the behavior of mantle plumes we can constrain the vigor of mantle convection, the net rotation of the mantle and the role of thermal versus chemical anomalies as well as the bulk physical properties such as the viscosity profile. To do this, we developed a new algorithm to trace plume-like features in shear-wave (Vs) seismic tomography models based on picking local minima in the velocity and searching for continuous features with depth. We applied this method to recent tomographic models and find 60+ continuous plume conduits that are > 750 km long. Approximately a third of these can be associated with known hotspots at the surface. We analyze the morphology of these continuous conduits and infer large scale mantle flow patterns and properties. We find the largest lateral deflections in the conduits occur near the base of the lower mantle and in the upper mantle (near the thermal boundary layers). The preferred orientation of the plume deflections show large variability at all depths and indicate no net mantle rotation. Plate by plate analysis shows little agreement in deflection below particular plates, indicating these deflected features might be long lived and not caused by plate shearing. Changes in the gradient of plume deflection are inferred to correspond with viscosity contrasts in the mantle and found below the transition zone as well as at 1000 km depth. From this inferred viscosity structure, we explore the dynamics of a plume through these viscosity jumps. We also retrieve the Vs profiles for the conduits and compare with the velocity profiles predicted for different mantle adiabat

  17. Tracking of smokestack and cooling tower plumes using wind measurements at different levels

    International Nuclear Information System (INIS)

    Miller, R.L.; Patrinos, A.A.N.

    1980-08-01

    Relationships between cooling tower and smokestack plumes at the Bowen Electric Generating Plant in northwestern Georgia and wind direction measurements at levels from the surface at 850 mb (approx. 1.5 km) are examined. The wind measurements play an important role in estimating plume directions which in turn are utilized to establish control and target (upwind and downwind) areas for a study of plant-induced precipitation modification. Fifty-two plume observations were made during a three week period in December 1979. Results indicate that a windset (4.5 km from the plant) mounted at a level approximating that of the cooling tower plume is a better predictor of plume direction than surface windsets (1.0 km from the plant) or 850 mb level winds. However, an apparent topographical influence on the wind direction measurements at the plume-level windset site somewhat limits its plume tracking capability, at least for ambient winds from the SW quadrant

  18. The effect of ochre applied to buffer zones on soluble phosphorus retention during combined surface and subsurface flow conditions

    Science.gov (United States)

    Habibiandehkordi, R.; Quinton, J.; Surridge, B.

    2012-12-01

    Despite invention of a wide range of mitigating measures, diffuse phosphorus (P) pollution from agricultural lands still remains a major threat to the water resources. Thus, reducing P inputs along with improving the effectiveness of current best management practices (BMPs) is necessary to avoid eutrophication. Buffer zones are considered to be among the BMPs to control diffuse P pollution. However, these features are less effective in controlling soluble P loss with a retention range of -71 to +95% which is generally governed by the process of infiltration. Moreover, the soil in buffer strip system can be saturated over a course of time thereby enriching surface and subsurface runoff with soluble P. The aim of this study is to evaluate effectiveness of ochre applied to buffer strips in reducing the loss of soluble P during coupled surface and subsurface flow conditions. Batch experiments showed a maximum P retention capacity of 17.2 g kg-1 for ochre collected from a mine water treatment plant in Capehouse, UK without any risk of P desorption or releasing trace elements to the environment. The preliminarily results of flume experiments confirms the suitability of ochre to be used as a soil amendment in conjunction with buffer strips for tackling soluble P loss.

  19. Mean shear flow in recirculating turbulent urban convection and the plume-puff eddy structure below stably stratified inversion layers

    Science.gov (United States)

    Fan, Yifan; Hunt, Julian; Yin, Shi; Li, Yuguo

    2018-03-01

    The mean and random components of the velocity field at very low wind speeds in a convective boundary layer (CBL) over a wide urban area are dominated by large eddy structures—either turbulent plumes or puffs. In the mixed layer at either side of the edges of urban areas, local mean recirculating flows are generated by sharp horizontal temperature gradients. These recirculation regions also control the mean shear profile and the bent-over plumes across the mixed layer, extending from the edge to the center of the urban area. A simplified physical model was proposed to calculate the mean flow speed at the edges of urban areas. Water tank experiments were carried out to study the mean recirculating flow and turbulent plume structures. The mean speed at urban edges was measured by the particle image velocimetry (PIV), and the plume structures were visualized by the thermalchromic liquid crystal (TLC) sheets. The horizontal velocity calculated by the physical model at the urban edge agrees well with that measured in the water tank experiments, with a root mean square of 0.03. The experiments also show that the pattern of the mean flow over the urban area changes significantly if the shape of the heated area changes or if the form of the heated urban area becomes sub-divided, for example by the creation of nearby but separated "satellite cities." The convective flow over the square urban area is characterized as the diagonal inflow at the lower level and the side outflow at the upper level. The outflow of the small city can be drawn into the inflow region of the large city in the "satellite city" case. A conceptual analysis shows how these changes significantly affect the patterns of dispersion of pollutants in different types of urban areas.

  20. Vapor plume oscillation mechanisms in transient keyhole during tandem dual beam fiber laser welding

    Science.gov (United States)

    Chen, Xin; Zhang, Xiaosi; Pang, Shengyong; Hu, Renzhi; Xiao, Jianzhong

    2018-01-01

    Vapor plume oscillations are common physical phenomena that have an important influence on the welding process in dual beam laser welding. However, until now, the oscillation mechanisms of vapor plumes remain unclear. This is primarily because mesoscale vapor plume dynamics inside a millimeter-scale, invisible, and time-dependent keyhole are difficult to quantitatively observe. In this paper, based on a developed three-dimensional (3D) comprehensive model, the vapor plume evolutions in a dynamical keyhole are directly simulated in tandem dual beam, short-wavelength laser welding. Combined with the vapor plume behaviors outside the keyhole observed by high-speed imaging, the vapor plume oscillations in dynamical keyholes at different inter-beam distances are the first, to our knowledge, to be quantitatively analyzed. It is found that vapor plume oscillations outside the keyhole mainly result from vapor plume instabilities inside the keyhole. The ejection velocity at the keyhole opening and dynamical behaviors outside the keyhole of a vapor plume both violently oscillate with the same order of magnitude of high frequency (several kHz). Furthermore, the ejection speed at the keyhole opening and ejection area outside the keyhole both decrease as the beam distance increases, while the degree of vapor plume instability first decreases and then increases with increasing beam distance from 0.6 to 1.0 mm. Moreover, the oscillation mechanisms of a vapor plume inside the dynamical keyhole irradiated by dual laser beams are investigated by thoroughly analyzing the vapor plume occurrence and flow process. The vapor plume oscillations in the dynamical keyhole are found to mainly result from violent local evaporations and severe keyhole geometry variations. In short, the quantitative method and these findings can serve as a reference for further understanding of the physical mechanisms in dual beam laser welding and of processing optimizations in industrial applications.

  1. Simulating Irregular Source Geometries for Ionian Plumes

    Science.gov (United States)

    McDoniel, W. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Buchta, D. A.; Freund, J.; Kieffer, S. W.

    2011-05-01

    Volcanic plumes on Io respresent a complex rarefied flow into a near-vacuum in the presence of gravity. A 3D Direct Simulation Monte Carlo (DSMC) method is used to investigate the gas dynamics of such plumes, with a focus on the effects of source geometry on far-field deposition patterns. A rectangular slit and a semicircular half annulus are simulated to illustrate general principles, especially the effects of vent curvature on deposition ring structure. Then two possible models for the giant plume Pele are presented. One is a curved line source corresponding to an IR image of a particularly hot region in the volcano's caldera and the other is a large area source corresponding to the entire caldera. The former is seen to produce the features seen in observations of Pele's ring, but with an error in orientation. The latter corrects the error in orientation, but loses some structure. A hybrid simulation of 3D slit flow is also discussed.

  2. Simulating Irregular Source Geometries for Ionian Plumes

    International Nuclear Information System (INIS)

    McDoniel, W. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Buchta, D. A.; Freund, J.; Kieffer, S. W.

    2011-01-01

    Volcanic plumes on Io respresent a complex rarefied flow into a near-vacuum in the presence of gravity. A 3D Direct Simulation Monte Carlo (DSMC) method is used to investigate the gas dynamics of such plumes, with a focus on the effects of source geometry on far-field deposition patterns. A rectangular slit and a semicircular half annulus are simulated to illustrate general principles, especially the effects of vent curvature on deposition ring structure. Then two possible models for the giant plume Pele are presented. One is a curved line source corresponding to an IR image of a particularly hot region in the volcano's caldera and the other is a large area source corresponding to the entire caldera. The former is seen to produce the features seen in observations of Pele's ring, but with an error in orientation. The latter corrects the error in orientation, but loses some structure. A hybrid simulation of 3D slit flow is also discussed.

  3. Turbulent structure of thermal plume. Velocity field

    International Nuclear Information System (INIS)

    Guillou, B.; Brahimi, M.; Doan-kim-son

    1986-01-01

    An experimental investigation and a numerical study of the dynamics of a turbulent plume rising from a strongly heated source are described. This type of flow is met in thermal effluents (air, vapor) from, e.g., cooling towers of thermal power plants. The mean and fluctuating values of the vertical component of the velocity were determined using a Laser-Doppler anemometer. The measurements allow us to distinguish three regions in the plume-a developing region near the source, an intermediate region, and a self-preserving region. The characteristics of each zone have been determined. In the self-preserving zone, especially, the turbulence level on the axis and the entrainment coefficient are almost twice of the values observed in jets. The numerical model proposed takes into account an important phenomenon, the intermittency, observed in the plume. This model, established with the self-preserving hypothesis, brings out analytical laws. These laws and the predicted velocity profile are in agreement with the experimental evolutions [fr

  4. Using MOPITT data and a Chemistry and Transport Model to Investigate Injection Height of Plumes from Boreal Forest Fires

    Science.gov (United States)

    Hyer, E. J.; Allen, D. J.; Kasischke, E. S.; Warner, J. X.

    2003-12-01

    Emissions from Boreal Forest Fires - 1996 to 2002." Lamarque, J.-F., D.P. Edwards, L.K. Emmons, J.C. Gille, O. Wilhelmi, C. Gerbig, D. Prevedel, M.N. Deeter, J.X. Warner, D.C. Ziskin, B. Khattatov, G.L. Francis, V. Yudin, S. Ho, D. Mao, J. Chen, J.R. Drummond. "Identification of CO plumes from MOPITT data: Application to the August 2000 Idaho-Montana forest fires." Geophysical Research Letters 30(13):1688, doi:10.1029/2003GL017503. Wotawa, G. and M. Trainer. "The influence of Canadian Forest Fires on Pollutant Concentrations in the United States." Science 288:324-328.

  5. Overview of NASA GRCs Green Propellant Infusion Mission Thruster Testing and Plume Diagnostics

    Science.gov (United States)

    Deans, Matthew C.; Reed, Brian D.; Yim, John T.; Arrington, Lynn A.; Williams, George J.; Kojima, Jun J.; McLean, Christopher H.

    2014-01-01

    The Green Propellant Infusion Mission (GPIM) is sponsored by NASA's Space Technology Mission Directorate (STMD) Technology Demonstration Mission (TDM) office. The goal of GPIM is to advance the technology readiness level of a green propulsion system, specifically, one using the monopropellant, AF-M315E, by demonstrating ground handling, spacecraft processing, and on-orbit operations. One of the risks identified for GPIM is potential contamination of sensitive spacecraft surfaces from the effluents in the plumes of AF-M315E thrusters. NASA Glenn Research Center (GRC) is conducting activities to characterize the effects of AF-M315E plume impingement and deposition. GRC has established individual plume models of the 22-N and 1-N thrusters that will be used on the GPIM spacecraft. The models describe the pressure, temperature, density, Mach number, and species concentration of the AF-M315E thruster exhaust plumes. The models are being used to assess the impingement effects of the AF-M315E thrusters on the GPIM spacecraft. The model simulations will be correlated with plume measurement data from Laboratory and Engineering Model 22-N, AF-M315E thrusters. The thrusters will be tested in a small rocket, altitude facility at NASA GRC. The GRC thruster testing will be conducted at duty cycles representatives of the planned GPIM maneuvers. A suite of laser-based diagnostics, including Raman spectroscopy, Rayleigh spectroscopy, Schlieren imaging, and physical probes will be used to acquire plume measurements of AFM315E thrusters. Plume data will include temperature, velocity, relative density, and species concentration. The plume measurement data will be compared to the corresponding simulations of the plume model. The GRC effort will establish a data set of AF-M315E plume measurements and a plume model that can be used for future AF-M315E applications.

  6. Potential of aerobic bacteria use for remediation of groundwater of Pavlodar outskirt contaminated with soluble mercury compounds

    Science.gov (United States)

    In the Republic of Kazakhstan there are some regions contaminated with mercury as a result of technogenic releases from industrial enterprises. The mercury ingress into the environment has resulted in significant pollution of groundwater and surface water with soluble mercury com...

  7. The EtnaPlumeLab (EPL research cluster: advance the understanding of Mt. Etna plume, from source characterisation to downwind impact

    Directory of Open Access Journals (Sweden)

    Pasquale Sellitto

    2017-01-01

    Full Text Available In 2013, a multidisciplinary research cluster named EtnaPlumeLab (EPL was established, gathering experts from volcanology and atmospheric science communities. Target of EPL is to advance the understanding of Mt. Etna's gas and aerosol emissions and the related processes, from source to its regional climatic impact in the Mediterranean area. Here, we present the cluster and its three interacting modules: EPL-RADIO (Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns, SMED (Sulfur MEditerranean Dispersion and Med-SuV (MEDiterranean SUpersite Volcanoes Work Package 5. Preliminary results have for the first time highlighted the relevance of Mt. Etna's plume impact at the Mediterranean regional scale. These results underline that further efforts need to be made to get insight into a synoptic volcanogenic-atmospheric chemistry/climatic understanding of volcanic plumes impact.

  8. A simple modeling approach to study the regional impact of a Mediterranean forest isoprene emission on anthropogenic plumes

    Directory of Open Access Journals (Sweden)

    J. Cortinovis

    2005-01-01

    Full Text Available Research during the past decades has outlined the importance of biogenic isoprene emission in tropospheric chemistry and regional ozone photo-oxidant pollution. The first part of this article focuses on the development and validation of a simple biogenic emission scheme designed for regional studies. Experimental data sets relative to Boreal, Tropical, Temperate and Mediterranean ecosystems are used to estimate the robustness of the scheme at the canopy scale, and over contrasted climatic and ecological conditions. A good agreement is generally found when comparing field measurements and simulated emission fluxes, encouraging us to consider the model suitable for regional application. Limitations of the scheme are nevertheless outlined as well as further on-going improvements. In the second part of the article, the emission scheme is used on line in the broader context of a meso-scale atmospheric chemistry model. Dynamically idealized simulations are carried out to study the chemical interactions of pollutant plumes with realistic isoprene emissions coming from a Mediterranean oak forest. Two types of anthropogenic sources, respectively representative of the Marseille (urban and Martigues (industrial French Mediterranean sites, and both characterized by different VOC/NOx are considered. For the Marseille scenario, the impact of biogenic emission on ozone production is larger when the forest is situated in a sub-urban configuration (i.e. downwind distance TOWN-FOREST -1. In this case the enhancement of ozone production due to isoprene can reach +37% in term of maximum surface concentrations and +11% in term of total ozone production. The impact of biogenic emission decreases quite rapidly when the TOWN-FOREST distance increases. For the Martigues scenario, the biogenic impact on the plume is significant up to TOWN-FOREST distance of 90km where the ozone maximum surface concentration enhancement can still reach +30%. For both cases, the

  9. Source identification and airborne chemical characterisation of aerosol pollution from long-range transport over Greenland during POLARCAT summer campaign 2008

    Directory of Open Access Journals (Sweden)

    J. Schmale

    2011-10-01

    Full Text Available We deployed an aerosol mass spectrometer during the POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport summer campaign in Greenland in June/July 2008 on the research aircraft ATR-42. Online size resolved chemical composition data of submicron aerosol were collected up to 7.6 km altitude in the region 60 to 71° N and 40 to 60° W. Biomass burning (BB and fossil fuel combustion (FF plumes originating from North America, Asia, Siberia and Europe were sampled. Transport pathways of detected plumes included advection below 700 hPa, air mass uplifting in warm conveyor belts, and high altitude transport in the upper troposphere. By means of the Lagrangian particle dispersion model FLEXPART, trace gas analysis of O3 and CO, particle size distributions and aerosol chemical composition 48 pollution events were identified and classified into five chemically distinct categories. Aerosol from North American BB consisted of 22% particulate sulphate, while with increasing anthropogenic and Asian influence aerosol in Asian FF dominated plumes was composed of up to 37% sulphate category mean value. Overall, it was found that the organic matter fraction was larger (85% in pollution plumes than for background conditions (71%. Despite different source regions and emission types the particle oxygen to carbon ratio of all plume classes was around 1 indicating low-volatility highly oxygenated aerosol. The volume size distribution of out-of-plume aerosol showed markedly smaller modes than all other distributions with two Aitken mode diameters of 24 and 43 nm and a geometric standard deviation σg of 1.12 and 1.22, respectively, while another very broad mode was found at 490 nm (σg = 2.35. Nearly pure BB particles from North America exhibited an Aitken mode at 66 nm (σg = 1.46 and an accumulation mode diameter of 392 nm (σg = 1

  10. Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke

    Science.gov (United States)

    G L Achtemeier; S L Goodrick; Y Liu; F Garcia-Menendez; Y Hu; M. Odman

    2011-01-01

    We present Daysmoke, an empirical-statistical plume rise and dispersion model for simulating smoke from prescribed burns. Prescribed fires are characterized by complex plume structure including multiple-core updrafts which makes modeling with simple plume models difficult. Daysmoke accounts for plume structure in a three-dimensional veering/sheering atmospheric...

  11. Generation of dense plume fingers in saturated-unsaturated homogeneous porous media

    Science.gov (United States)

    Cremer, Clemens J. M.; Graf, Thomas

    2015-02-01

    Flow under variable-density conditions is widespread, occurring in geothermal reservoirs, at waste disposal sites or due to saltwater intrusion. The migration of dense plumes typically results in the formation of vertical plume fingers which are known to be triggered by material heterogeneity or by variations in source concentration that causes the density variation. Using a numerical groundwater model, six perturbation methods are tested under saturated and unsaturated flow conditions to mimic heterogeneity and concentration variations on the pore scale in order to realistically generate dense fingers. A laboratory-scale sand tank experiment is numerically simulated, and the perturbation methods are evaluated by comparing plume fingers obtained from the laboratory experiment with numerically simulated fingers. Dense plume fingering for saturated flow can best be reproduced with a spatially random, time-constant perturbation of the solute source. For unsaturated flow, a spatially and temporally random noise of solute concentration or a random conductivity field adequately simulate plume fingering.

  12. Numerical modeling of flows and pollutant dispersion within and above urban street canyons under unstable thermal stratification by large-eddy simulation

    Science.gov (United States)

    Chan, Ming-Chung; Liu, Chun-Ho

    2013-04-01

    intensity of stratification is controlled by the gravitational acceleration. The urban characteristic is modeled by periodic boundary conditions at the domain inlet-outlet and spanwise extent, so as to simulate the infinitely long and wide urban area. Pollutant dispersion is modeled by scalar transport with the pollutant area source on the ground of the first street canyon and by open boundary condition at the domain outlet. The numerical models are solved with incremental time steps until it reaches the pseudo steady-state. Afterwards, a set of data is collected for each model such that the temporal averages of mean and fluctuating field variables do not vary significantly if more time steps are included. It is found that the ventilation performance is improved and the plume dispersion in shear layer is enhanced when the stratification is more unstable. The mean flows, turbulent transports of pollutant and momentum, pollutant concentration fields in different unstable stratifications will be discussed with profile and contour plots. The ventilation performance of a street canyon evaluated by air exchange rate (ACH) and pollutant exchange rate (PCH) at roof level and the plume dispersion characterized by the mean plume height and dispersion coefficient in shear layer will also be discussed.

  13. Tritium plume dynamics in the shallow unsaturated zone in an arid environment

    Science.gov (United States)

    Maples, S.R.; Andraski, Brian J.; Stonestrom, David A.; Cooper, C.A.; Pohll, G.; Michel, R.L.

    2014-01-01

    The spatiotemporal variability of a tritium plume in the shallow unsaturated zone and the mechanisms controlling its transport were evaluated during a 10-yr study. Plume movement was minimal and its mass declined by 68%. Upward-directed diffusive-vapor tritium fluxes and radioactive decay accounted for most of the observed plume-mass declines.Effective isolation of tritium (3H) and other contaminants at waste-burial facilities requires improved understanding of transport processes and pathways. Previous studies documented an anomalously widespread (i.e., theoretically unexpected) distribution of 3H (>400 m from burial trenches) in a dry, sub-root-zone gravelly layer (1–2-m depth) adjacent to a low-level radioactive waste (LLRW) burial facility in the Amargosa Desert, Nevada, that closed in 1992. The objectives of this study were to: (i) characterize long-term, spatiotemporal variability of 3H plumes; and (ii) quantify the processes controlling 3H behavior in the sub-root-zone gravelly layer beneath native vegetation adjacent to the facility. Geostatistical methods, spatial moment analyses, and mass flux calculations were applied to a spatiotemporally comprehensive, 10-yr data set (2001–2011). Results showed minimal bulk-plume advancement during the study period and limited Fickian spreading of mass. Observed spreading rates were generally consistent with theoretical vapor-phase dispersion. The plume mass diminished more rapidly than would be expected from radioactive decay alone, indicating net efflux from the plume. Estimates of upward 3H efflux via diffusive-vapor movement were >10× greater than by dispersive-vapor or total-liquid movement. Total vertical fluxes were >20× greater than lateral diffusive-vapor fluxes, highlighting the importance of upward migration toward the land surface. Mass-balance calculations showed that radioactive decay and upward diffusive-vapor fluxes contributed the majority of plume loss. Results indicate that plume losses

  14. Hybrid technologies for the remediation of Diesel fuel polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Pazos, M.; Alcantara, M.T.; Rosales, E.; Sanroman, M.A. [Department of Chemical Engineering, University of Vigo (Spain)

    2011-12-15

    Diesel fuel may be released into soil due to anthropogenic activities, such as accidental spills or leaks in underground storage tanks or pipelines. Since diesel fuel is mainly composed of hydrophobic organic compounds, it has low water solubility. Therefore, treating contaminated areas with conventional techniques is difficult. In this study, electrokinetic treatment of soil contaminated with diesel fuel was carried out. Two different hybrid approaches to pollutant removal were tested. A surfactant was used as a processing fluid during electrokinetic treatment to increase desorption and the solubility of diesel fuel. Additionally, a hybrid technology combining a Fenton reaction and electrokinetic remediation (EK-Fenton) was tested in an attempt to generate favorable in situ degradation of pollutants. The efficiency of each treatment was determined based on diesel fuel removal. After 30 days of treatment, the highest removal of diesel fuel was found to be achieved with the EK-Fenton process. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Experimental investigation of the hydrodynamics of confined bubble plumes in water and viscous media

    International Nuclear Information System (INIS)

    Brahma N Reddy Vanga; Martin A Lopez de Bertodano; Alexandr Zaruba; Eckhard Krepper; Horst-Michael Prasser

    2005-01-01

    Wire-mesh tomography measurements of void fraction and bubble size distribution in a rectangular bubble column 10 cm wide and 2 cm deep have been conducted. Experiments were performed in an air-water and ethylene glycol system with the column operating in the dispersed bubbly flow regime.Experiments were conducted for plumes with different aspect ratios between 2.2 to 13. The experiments also serve the purpose of studying the performance of wire-mesh sensors in batch flows. The behaviour of the long plumes (larger aspect ratio) was found to be significantly different than that of the short plumes (aspect ratios 2 to 4). The oscillating nature of the bubble plume is preserved over the entire height of the water column for the short plumes. The longer plumes are characterized by two distinct regions, the near injector oscillating region and a further downstream region where the bubbles rise in a string like motion. The void fraction distribution in the oscillating region of the plume exhibits a center-peak profile. A 'wall peak' has been observed in the measured void fraction profiles (for higher gas flow rates) in the downstream string-like region. The effect of column height and superficial gas velocity on the void distribution has been investigated. This paper presents the measurement principle and the experimental results for short and long plumes in an air-water system and for short plumes rising in viscous media. The results of the visualization experiment characterizing the structure of the bubble plume and the oscillation frequency of the bubble plumes are reported. (authors)

  16. New method for calculation of integral characteristics of thermal plumes

    DEFF Research Database (Denmark)

    Zukowska, Daria; Popiolek, Zbigniew; Melikov, Arsen Krikor

    2008-01-01

    A method for calculation of integral characteristics of thermal plumes is proposed. The method allows for determination of the integral parameters of plumes based on speed measurements performed with omnidirectional low velocity thermoanemometers. The method includes a procedure for calculation...... of the directional velocity (upward component of the mean velocity). The method is applied for determination of the characteristics of an asymmetric thermal plume generated by a sitting person. The method was validated in full-scale experiments in a climatic chamber with a thermal manikin as a simulator of a sitting...

  17. Utilization of a hydraulic barrier to control migration of a uranium plume

    International Nuclear Information System (INIS)

    Brettschneider, D.J.; Simmons, R.A. Jr.; Kappa, J.D.; Stover, J.A.

    1995-01-01

    A uranium plume emanating from the U.S. Department of Energy's Fernald Environmental Management Project (FEMP) in Fernald, Ohio had migrated off site and the leading edge of the plume had already mixed with an organic and inorganic plume emanating from two industries south of the FEMP. A method was needed to prevent the further southern migration of the plume, minimize any impacts to the geometry, concentrations, distribution or flow patterns of the organic and inorganic plumes emanating from the off-site industries, while meeting the ultimate cleanup goals for the FEMP. This paper discusses the use of a hydraulic barrier created to meet these goals by pumping a five well recovery system and the problems associated with the disposition of over 2 million gallons per day of water with low concentrations of uranium

  18. Field studies of submerged-diffuser thermal plumes with comparisons to predictive model results

    International Nuclear Information System (INIS)

    Frigo, A.A.; Paddock, R.A.; Ditmars, J.D.

    1976-01-01

    Thermal plumes from submerged discharges of cooling water from two power plants on Lake Michigan were studied. The system for the acquisition of water temperatures and ambient conditions permitted the three-dimensional structure of the plumes to be determined. The Zion Nuclear Power Station has two submerged discharge structures separated by only 94 m. Under conditions of flow from both structures, interaction between the two plumes resulted in larger thermal fields than would be predicted by the superposition of single non-interacting plumes. Maximum temperatures in the near-field region of the plume compared favorably with mathematical model predictions. A comparison of physical-model predictions for the plume at the D. C. Cook Nuclear Plant with prototype measurements indicated good agreement in the near-field region, but differences in the far-field occurred as similitude was not preserved there

  19. Appearance and water quality of turbidity plumes produced by dredging in Tampa Bay, Florida

    Science.gov (United States)

    Goodwin, Carl R.; Michaelis, D.M.

    1984-01-01

    Turbidity plumes in Tampa Bay, Florida, produced during ship-channel dredging operations from February 1977 to August 1978, were monitored in order to document plume appearance and water quality, evaluate plume influence on the characteristics of Tampa Bay water, and provide a data base for comparison with other areas that have similar sediment, dredge, placement, containment, and tide conditions. The plumes investigated originated from the operation of one hopper dredge and three cutterhead-pipeline dredges. Composition of bottom sediment was found to vary from 85 percent sand and shell fragments to 60 percent silt and clay. Placement methods for dredged sediment included beach nourishment, stationary submerged discharge, oscillating surface discharge, and construction of emergent dikes. Tidal currents ranged from slack water to flow velocities of 0.60 meter per second. Plumes were monitored simultaneously by (1) oblique and vertical 35-millimeter aerial photography and (2) water-quality sampling to determine water clarity and concentrations of nutrients, metals, pesticides, and industrial compounds. Forty-nine photographs depict plumes ranging in length from a few tens of meters to several kilometers and ranging in turbidity level from hopper-dredge unloading operations also produced plumes of low visibility. Primary turbidity plumes were produced directly by dredging and placement operations; secondary plumes were produced indirectly by resuspension of previously deposited material. Secondary plumes were formed both by erosion, in areas of high-velocity tidal currents, and by turbulence from vessels passing over fine material deposited in shallow areas. Where turbidity barriers were not used, turbidity plumes visible at the surface were good indicators of the location of turbid water at depth. Where turbidity barriers were used, turbid bottom water was found at locations having no visible surface plumes. A region of rapidly accelerating then decelerating flow

  20. Dynamics of Mantle Plume Controlled by both Post-spinel and Post-garnet Phase Transitions

    Science.gov (United States)

    Liu, H.; Leng, W.

    2017-12-01

    Mineralogical studies indicate that two major phase transitions occur near 660 km depth in the Earth's pyrolitic mantle: the ringwoodite (Rw) to perovskite (Pv) + magnesiowüstite (Mw) and majorite (Mj) to perovskite (Pv) phase transitions. Seismological results also show a complicated phase boundary structure for plume regions at this depth, including broad pulse, double reflections and depressed 660 km discontinuity beneath hot regions etc… These observations have been attributed to the co-existence of these two phase transformations. However, previous geodynamical modeling mainly focused on the effects of Rw-Pv+Mw phase transition on the plume dynamics and largely neglected the effects of Mj-Pv phase transition. Here we develop a 3-D regional spherical geodynamic model to study the influence of the combination of Rw - Pv+Mw and Mj - Pv phase transitions on plume dynamics, including the topography fluctuation of 660 km discontinuity, plume shape and penetration capability of plume. Our results show that (1) a double phase boundary occurs at the hot center area of plume while for other regions with relatively lower temperature the phase boundary is single and flat, which respectively corresponds to the double reflections in the seismic observations and a high velocity prism-like structure at the top of 660 km discontinuity; (2) a large amount of low temperature plume materials could be trapped to form a complex trapezoid overlying the 660 km depth; (3) Mj - Pv phase change strongly enhances the plume penetration capability at 660 km depth, which significantly increases the plume mass flux due to the increased plume radius, but significantly reduces plume heat flux due to the decreased plume temperature in the upper mantle. Our model results provide new enlightenments for better constraining seismic structure and mineral reactions at 660 km phase boundaries.

  1. Heat and mass transfer in the mushroom-shaped head of mantle plume

    Directory of Open Access Journals (Sweden)

    Kirdyashkin Anatoly

    2017-01-01

    Full Text Available The results of experimental and theoretical modeling of free-convection flows in the melt of the plume conduit and in the mushroom-shaped head are presented. It was shown that the plumes with the mushroom-shaped heads can be responsible for the batholith formation. The main parameters of such plumes are estimated.

  2. Measurements at cooling tower plumes. Pt. 1

    International Nuclear Information System (INIS)

    Gassmann, F.; Haschke, D.; Solfrian, W.

    1976-04-01

    Referring to the present status of knowledge model conceptions, assumptions and approaches are summarized, which can lead to mathematical models for the simulation of dry or wet cooling tower plumes. By developing a one-dimensional plume model (FOG) the most important problems are considered in detail. It is shown that for the calibration of the necessary parameters as well as for the development of models full scale measurements are of decisive importance. After a discussion of different possibilities of measurement the organisation of a campaign of measurement is described. (orig.) [de

  3. Kinetic electron model for plasma thruster plumes

    Science.gov (United States)

    Merino, Mario; Mauriño, Javier; Ahedo, Eduardo

    2018-03-01

    A paraxial model of an unmagnetized, collisionless plasma plume expanding into vacuum is presented. Electrons are treated kinetically, relying on the adiabatic invariance of their radial action integral for the integration of Vlasov's equation, whereas ions are treated as a cold species. The quasi-2D plasma density, self-consistent electric potential, and electron pressure, temperature, and heat fluxes are analyzed. In particular, the model yields the collisionless cooling of electrons, which differs from the Boltzmann relation and the simple polytropic laws usually employed in fluid and hybrid PIC/fluid plume codes.

  4. Plutonium solubilities

    International Nuclear Information System (INIS)

    Puigdomnech, I.; Bruno, J.

    1991-02-01

    Thermochemical data has been selected for plutonium oxide, hydroxide, carbonate and phosphate equilibria. Equilibrium constants have been evaluated in the temperature range 0 to 300 degrees C at a pressure of 1 bar to T≤100 degrees C and at the steam saturated pressure at higher temperatures. Measured solubilities of plutonium that are reported in the literature for laboratory experiments have been collected. Solubility data on oxides, hydroxides, carbonates and phosphates have been selected. No solubility data were found at temperatures higher than 60 degrees C. The literature solubility data have been compared with plutonium solubilities calculated with the EQ3/6 geochemical modelling programs, using the selected thermodynamic data for plutonium. (authors)

  5. Characterization of ablated species in laser-induced plasma plume

    International Nuclear Information System (INIS)

    Furusawa, Hideki; Sakka, Tetsuo; Ogata, Yukio H.

    2004-01-01

    Plasma electron density and atomic population densities in the plasma plume produced by a laser ablation of aluminum metal were determined in various ambient gases at relatively high pressures. The method is based on the fit of a spectral line profile of Al(I) 2 P (convolutionsign) - 2 S emission to the theoretical spectrum obtained by one-dimensional radiative transfer calculation. The electron density was higher for a higher ambient gas pressure, suggesting the confinement of the plume by an ambient gas. The electron density also depends on the type of ambient gases, i.e., it increased in the order He 4 2 4 , while the atomic population density is almost independent of the type of ambient species and pressure. The population densities of the upper and lower levels of the transition were compared, and the ratio between their spatial distribution widths was calculated. These results provide valuable information regarding the confinement of the plume by the ambient gas and give insight into the time evolution of the plume

  6. Natural attenuation: A feasible approach to remediation of landfill leachate plumes?

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Kjeldsen, Peter; Bjerg, Poul Løgstrup

    2000-01-01

    Natural attenuation has been implemented for petroleum hydrocarbons plumes and recently also for chlorinated solvent plumes, primarily in the USA, but natural attenuation has not yet gained a foothold with respect to leachate plumes. Based on the experiences gained from ten years of research on two...... Danish landfills, it is suggested that natural attenuation is a feasible approach, but much more complicated and demanding than in the case of petroleum hydrocarbons and chlorinated solvent....

  7. Comparative cytotoxicity and genotoxicity of soluble and particulate hexavalent chromium in human and hawksbill sea turtle (Eretmochelys imbricata) skin cells.

    Science.gov (United States)

    Young, Jamie L; Wise, Sandra S; Xie, Hong; Zhu, Cairong; Fukuda, Tomokazu; Wise, John Pierce

    2015-12-01

    Chromium is both a global marine pollutant and a known human health hazard. In this study, we compare the cytotoxicity and genotoxicity of both soluble and particulate chromate in human and hawksbill sea turtle (Eretmochelys imbricata) skin fibroblasts. Our data show that both soluble and particulate Cr(VI) induce concentration-dependent increases in cytotoxicity, genotoxicity, and intracellular Cr ion concentrations in both human and hawksbill sea turtle fibroblasts. Based on administered concentration, particulate and soluble Cr(VI) were more cytotoxic and clastogenic to human cells than sea turtle cells. When the analysis was based on the intracellular concentration of Cr, the data showed that the response of both species was similar. The one exception was the cytotoxicity of intracellular Cr ions from soluble Cr(VI), which caused more cytotoxicity in sea turtle cells (LC50=271μM) than that of human cells (LC50=471μM), but its clastogenicity was similar between the two species. Thus, adjusting for differences in uptake indicated that the explanation for the difference in potency was mostly due to uptake rather than differently affected mechanisms. Overall these data indicate that sea turtles may be a useful sentinel for human health responses to marine pollution. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Formation of mantle "lone plumes" in the global downwelling zone - A multiscale modelling of subduction-controlled plume generation beneath the South China Sea

    Science.gov (United States)

    Zhang, Nan; Li, Zheng-Xiang

    2018-01-01

    It has been established that almost all known mantle plumes since the Mesozoic formed above the two lower mantle large low shear velocity provinces (LLSVPs). The Hainan plume is one of the rare exceptions in that instead of rising above the LLSVPs, it is located within the broad global mantle downwelling zone, therefore classified as a "lone plume". Here, we use the Hainan plume example to investigate the feasibility of such lone plumes being generated by subducting slabs in the mantle downwelling zone using 3D geodynamic modelling. Our geodynamic model has a high-resolution regional domain embedded in a relatively low resolution global domain, which is set up in an adaptive-mesh-refined, 3D mantle convection code ASPECT (Advanced Solver for Problems in Earth's ConvecTion). We use a recently published plate motion model to define the top mechanical boundary condition. Our modelling results suggest that cold slabs under the present-day Eurasia, formed from the Mesozoic subduction and closure of the Tethys oceans, have prevented deep mantle hot materials from moving to the South China Sea from regions north or west of the South China Sea. From the east side, the Western Pacific subduction systems started to promote the formation of a lower-mantle thermal-chemical pile in the vicinity of the future South China Sea region since 70 Ma ago. As the top of this lower-mantle thermal-chemical pile rises, it first moved to the west, and finally rested beneath the South China Sea. The presence of a thermochemical layer (possible the D″ layer) in the model helps stabilizing the plume root. Our modelling is the first implementation of multi-scale mesh in the regional model. It has been proved to be an effective way of modelling regional dynamics within a global plate motion and mantle dynamics background.

  9. Magnetotelluric Detection Thresholds as a Function of Leakage Plume Depth, TDS and Volume

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buscheck, T. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mansoor, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Carroll, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-21

    We conducted a synthetic magnetotelluric (MT) data analysis to establish a set of specific thresholds of plume depth, TDS concentration and volume for detection of brine and CO2 leakage from legacy wells into shallow aquifers in support of Strategic Monitoring Subtask 4.1 of the US DOE National Risk Assessment Partnership (NRAP Phase II), which is to develop geophysical forward modeling tools. 900 synthetic MT data sets span 9 plume depths, 10 TDS concentrations and 10 plume volumes. The monitoring protocol consisted of 10 MT stations in a 2×5 grid laid out along the flow direction. We model the MT response in the audio frequency range of 1 Hz to 10 kHz with a 50 Ωm baseline resistivity and the maximum depth up to 2000 m. Scatter plots show the MT detection thresholds for a trio of plume depth, TDS concentration and volume. Plumes with a large volume and high TDS located at a shallow depth produce a strong MT signal. We demonstrate that the MT method with surface based sensors can detect a brine and CO2 plume so long as the plume depth, TDS concentration and volume are above the thresholds. However, it is unlikely to detect a plume at a depth larger than 1000 m with the change of TDS concentration smaller than 10%. Simulated aquifer impact data based on the Kimberlina site provides a more realistic view of the leakage plume distribution than rectangular synthetic plumes in this sensitivity study, and it will be used to estimate MT responses over simulated brine and CO2 plumes and to evaluate the leakage detectability. Integration of the simulated aquifer impact data and the MT method into the NRAP DREAM tool may provide an optimized MT survey configuration for MT data collection. This study presents a viable approach for sensitivity study of geophysical monitoring methods for leakage detection. The results come in handy for rapid assessment of leakage detectability.

  10. Io's UV-V Eclipse Emission: Implications for Pele-type Plumes

    Science.gov (United States)

    Moore, C. H.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

    2010-03-01

    Simulations of Io's NUV-V emission in eclipse show that S2-rich giant plumes' S2 concentrations and activity levels effect the absolute brightness and the east/west intensity ratio across Io allowing for plume activity to be determined from observed spectra.

  11. Comparison of in situ observations of air traffic emission signatures in the North Atlantic flight corridor with simulations using a Gaussian plume model

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, P; Schlager, H; Schulte, P; Schumann, U; Ziereis, H [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere; Hagen, D; Whitefield, P [Missouri Univ., Rolla, MO (United States). Lab. for Cloud and Aerosol Science

    1998-12-31

    Focussed aircraft measurements including NO, NO{sub 2}, O{sub 3}, and aerosols (CN) have been carried out over the Eastern North Atlantic as part of the POLINAT (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) project to search for small and large scale signals of air traffic emissions in the corridor region. Here, the experimental data measured at cruising altitudes on November, 6, 1994 close to peak traffic hours are considered. Observed peak concentrations in small scale NO{sub x} spikes exceed background level of about 50 pptv by up to two orders of magnitude. The measured NO{sub x} concentration field is compared with simulations obtained with a plume dispersion model using collected air traffic data and wind measurements. Additionally, the measured and calculated NO/NO{sub x} ratios are considered. The comparison with the model shows that the observed (multiple-)peaks can be understood as a superposition of several aircraft plumes with ages up to 3 hours. (author) 12 refs.

  12. Comparison of in situ observations of air traffic emission signatures in the North Atlantic flight corridor with simulations using a Gaussian plume model

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, P.; Schlager, H.; Schulte, P.; Schumann, U.; Ziereis, H. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere; Hagen, D.; Whitefield, P. [Missouri Univ., Rolla, MO (United States). Lab. for Cloud and Aerosol Science

    1997-12-31

    Focussed aircraft measurements including NO, NO{sub 2}, O{sub 3}, and aerosols (CN) have been carried out over the Eastern North Atlantic as part of the POLINAT (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) project to search for small and large scale signals of air traffic emissions in the corridor region. Here, the experimental data measured at cruising altitudes on November, 6, 1994 close to peak traffic hours are considered. Observed peak concentrations in small scale NO{sub x} spikes exceed background level of about 50 pptv by up to two orders of magnitude. The measured NO{sub x} concentration field is compared with simulations obtained with a plume dispersion model using collected air traffic data and wind measurements. Additionally, the measured and calculated NO/NO{sub x} ratios are considered. The comparison with the model shows that the observed (multiple-)peaks can be understood as a superposition of several aircraft plumes with ages up to 3 hours. (author) 12 refs.

  13. Martian methane plume models for defining Mars rover methane source search strategies

    Science.gov (United States)

    Nicol, Christopher; Ellery, Alex; Lynch, Brian; Cloutis, Ed

    2018-07-01

    The detection of atmospheric methane on Mars implies an active methane source. This introduces the possibility of a biotic source with the implied need to determine whether the methane is indeed biotic in nature or geologically generated. There is a clear need for robotic algorithms which are capable of manoeuvring a rover through a methane plume on Mars to locate its source. We explore aspects of Mars methane plume modelling to reveal complex dynamics characterized by advection and diffusion. A statistical analysis of the plume model has been performed and compared to analyses of terrestrial plume models. Finally, we consider a robotic search strategy to find a methane plume source. We find that gradient-based techniques are ineffective, but that more sophisticated model-based search strategies are unlikely to be available in near-term rover missions.

  14. Simulations of the Effects of Jupiter's Plasma Torus on Io's Pele Plume

    Science.gov (United States)

    McDoniel, William; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.

    2014-11-01

    Io’s plumes rise hundreds of kilometers above its surface and sublimation atmosphere, presenting large targets for incoming ions from Jupiter’s plasma torus. The direct simulation Monte Carlo method is used to model the gas plume at Pele and its interaction with the Jovian plasma torus. Chemical reactions resulting from ion impacts in a plume change its composition and energy from the impacts changes the plume’s structure (asymmetrically). The presence of non-condensible daughter species in a warmer plume canopy produces a more diffuse deposition ring on Io’s surface, compared to simulations without plasma. Energized molecules also escape from the plume, forming a diffuse cloud of fast particles above the plume’s canopy, which may function to resupply the plasma torus and which suggests a mechanism for lofting other species to very high altitudes.

  15. Spatial and temporal migration of a landfill leachate plume in alluvium

    Science.gov (United States)

    Masoner, Jason R.; Cozzarelli, Isabelle M.

    2015-01-01

    Leachate from unlined or leaky landfills can create groundwater contaminant plumes that last decades to centuries. Understanding the dynamics of leachate movement in space and time is essential for monitoring, planning and management, and assessment of risk to groundwater and surface-water resources. Over a 23.4-year period (1986–2010), the spatial extent of the Norman Landfill leachate plume increased at a rate of 7800 m2/year and expanded by 878 %, from an area of 20,800 m2 in 1986 to 203,400 m2 in 2010. A linear plume velocity of 40.2 m/year was calculated that compared favorably to a groundwater-seepage velocity of 55.2 m/year. Plume-scale hydraulic conductivity values representative of actual hydrogeological conditions in the alluvium ranged from 7.0 × 10−5 to 7.5 × 10−4 m/s, with a median of 2.0 × 10−4 m/s. Analyses of field-measured and calculated plume-scale hydraulic conductivity distributions indicate that the upper percentiles of field-measured values should be considered to assess rates of plume-scale migration, spreading, and biodegradation. A pattern of increasing Cl− concentrations during dry periods and decreasing Cl− concentrations during wet periods was observed in groundwater beneath the landfill. The opposite occurred in groundwater downgradient from the landfill; that is, Cl− concentrations in groundwater downgradient from the landfill decreased during dry periods and increased during wet periods. This pattern of changing Cl−concentrations in response to wet and dry periods indicates that the landfill retains or absorbs leachate during dry periods and produces lower concentrated leachate downgradient. During wet periods, the landfill receives more recharge which dilutes leachate in the landfill but increases leachate migration from the landfill and produces a more concentrated contaminant plume. This approach of quantifying plume expansion, migration, and concentration during variable hydrologic

  16. Comparative cytotoxicity and genotoxicity of soluble and particulate hexavalent chromium in human and hawksbill sea turtle (Eretmochelys imbricate) skin cells

    OpenAIRE

    Young, Jamie L.; Wise, Sandra S.; Xie, Hong; Zhu, Cairong; Fukuda, Tomokazu; Wise, John Pierce

    2015-01-01

    Chromium is both a global marine pollutant and a known human health hazard. In this study, we compare the cytotoxicity and genotoxicity of both soluble and particulate chromate in human and hawksbill sea turtle (Eretmochelys imbricata) skin fibroblasts. Our data show that both soluble and particulate Cr(VI) induce concentration-dependent increases in cytotoxicity, genotoxicity, and intracellular Cr ion concentrations in both human and hawksbill sea turtle fibroblasts. Based on administered co...

  17. Sediment plume response to surface melting and supraglacial lake drainages on the Greenland ice sheet

    DEFF Research Database (Denmark)

    Chu, Vena W.; Smith, Laurence C; Rennermalm, Asa K.

    2009-01-01

    ) supraglacial lake drainage events from MODIS. Results confirm that the origin of the sediment plume is meltwater release from the ice sheet. Interannual variations in plume area reflect interannual variations in surface melting. Plumes appear almost immediately with seasonal surface-melt onset, provided...... the estuary is free of landfast sea ice. A seasonal hysteresis between melt extent and plume area suggests late-season exhaustion in sediment supply. Analysis of plume sensitivity to supraglacial events is less conclusive, with 69% of melt pulses and 38% of lake drainage events triggering an increase in plume...... area. We conclude that remote sensing of sediment plume behavior offers a novel tool for detecting the presence, timing and interannual variability of meltwater release from the ice sheet....

  18. Plant odour plumes as mediators of plant-insect interactions.

    Science.gov (United States)

    Beyaert, Ivo; Hilker, Monika

    2014-02-01

    Insect olfactory orientation along odour plumes has been studied intensively with respect to pheromonal communication, whereas little knowledge is available on how plant odour plumes (POPs) affect olfactory searching by an insect for its host plants. The primary objective of this review is to examine the role of POPs in the attraction of insects. First, we consider parameters of an odour source and the environment which determine the size, shape and structure of an odour plume, and we apply that knowledge to POPs. Second, we compare characteristics of insect pheromonal plumes and POPs. We propose a 'POP concept' for the olfactory orientation of insects to plants. We suggest that: (i) an insect recognises a POP by means of plant volatile components that are encountered in concentrations higher than a threshold detection limit and that occur in a qualitative and quantitative blend indicating a resource; (ii) perception of the fine structure of a POP enables an insect to distinguish a POP from an unspecific odorous background and other interfering plumes; and (iii) an insect can follow several POPs to their sources, and may leave the track of one POP and switch to another one if this conveys a signal with higher reliability or indicates a more suitable resource. The POP concept proposed here may be a useful tool for research in olfactory-mediated plant-insect interactions. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

  19. Resolving superimposed ground-water contaminant plumes characterized by chromium, nitrate, uranium, and technetium--99

    International Nuclear Information System (INIS)

    Hall, S.H.

    1990-02-01

    Leakage from a liquid waste storage and solar evaporation basin at the Hanford Site in southeastern Washington State has resulted in a ground-water contaminant plume characterized by nitrate, hexavalent chromium, uranium, and technetium-99. The plume is superimposed on a larger, pre-existing plume extending from upgradient sites and having the same suite of contaminants. However, the relative abundance of contaminant species is quite different for each plume source. Thus, characteristic concentration ratios, rather than concentrations of individual species, are used as geochemical tracers, with emphasis on graphical analysis. Accordingly, it has been possible to resolve the boundaries of the smaller plume and to estimate the contribution of each plume to the observed contamination downgradient from the storage basin. 11 refs., 7 figs

  20. Monitoring and forecasting Etna volcanic plumes

    Directory of Open Access Journals (Sweden)

    S. Scollo

    2009-09-01

    Full Text Available In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i downloading weather forecast data from meteorological mesoscale models; ii running models of tephra dispersal, iii plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  1. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter

    Axisymmeric circular buoyant jets are treated both theoretically and experimentally. From a literature study the author concludes that the state of experimental knowledge is less satisfactory. Further three different measuring methods have been established to investigate the thermal plumes from...

  2. The role of plumes in mantle helium fluxes

    International Nuclear Information System (INIS)

    Kellogg, L.H.; Wasserburg, G.J.

    1990-01-01

    We present a simple model of 3 He and 4 He transport in the mantle using the appropriate rates of mass and species transfer and 4 He production. Previous workers have shown the presence of excess 3 He in hotspots such as Hawaii and Iceland and inferred that these hotspots tap a source with a higher 3 He/ 4 He ratio than the source region of mid-ocean ridge basalts (MORB). Hotspot ocean islands probably originate over upwelling plumes which carry material from the lower mantle to the upper mantle. Melting at hotspots and at mid-ocean ridges degasses the mantle of volatiles such as helium. The upper mantle is outgassed largely of helium due to melting at mid-ocean ridges and hotspots. We postulate that the excess 3 He seen in MORB originates in material that was carried from the lower mantle in plumes but not completely outgassed at hotspots. This helium is incoporated into the depleted upper mantle. Assuming that the upper mantle is in a quasi-steady-state with respect to helium, a simple model balancing 3 He and 4 He fluxes in the upper mantle indicates that the hotspots significantly outgas the lower mantle of 3 He. The concentration of 4 He in the plume source reservoir is 2-3 orders of magnitude lower than the concentration in carbonaceous chondrites. The residence time of helium in the upper mantle depends on the outgassing efficiency at hotspots, since the hotspots may outgas some upper mantle material which has been entrained in the plumes. The residence time of He in the upper mantle is about 1.4x10 9 yr. We conclude that the efficiency of outgassing of He from plumes is high and that the plumes dominate the present 3 He loss to the atmosphere. The 4 He in the less depleted layer of the mantle is not trapped ''primordial'' but is predominantly from in situ decay of U and Th in the depleted layer over ≅ 1.4x10 9 yr. The 4 He in the lower mantle is dominantly from in situ decay of U and Th over 4.4x10 9 yr. (orig./WL)

  3. Oil characterisation: assessment of composition, risks, degradation and remediation potential of total petroleum hydrocarbons in soil

    Energy Technology Data Exchange (ETDEWEB)

    Lookman, R.; Vanermen, G.; Van De Weghe, H.; Gemoets, J. [Vito, Mol (Belgium); Van der Sterren, G.; Alphenaar, A. [TTE, Deventer (Netherlands)

    2005-07-01

    Several methods are available for the characterization of petroleum hydrocarbons. The TPHCWG (Total Petroleum Hydrocarbon Criteria Working Group) developed a method based on a silica column separation of aromatics and aliphatics and a GC-FID subdivision into equivalent-carbon fractions (EC) ('TPH-method'). This method was mainly developed for assessing human risks of oil compounds. Within NOBIS (Dutch Research program Biological In-situ Remediation), another method was developed based upon an equilibrium-experiment of the oil-polluted soil with water (column recirculation), which was further developed by TTE ('TTE-method'). This method uses measured water solubilities of individual oil components and GC-retention times yielding a subdivision of the hydrocarbons into compound classes that are relevant for assessing the remediation potential of the specific oil pollution. In this paper we present results of a research project in which we developed a new method, the 'OK-method' that combines these two procedures and allows a complete characterisation of the oil in terms of composition, (human) risks, volatility, solubility, plume behaviour (migration velocities of the soluble components) and aerobic degradation potential. (authors)

  4. Characterization and Comparison of Aluminum, Silicon, and Carbon Laser Ablation Plumes

    Science.gov (United States)

    Iratcabal, Jeremy; Swanson, Kyle; Covington, Aaron

    2017-10-01

    Laser ablation of solid targets produces plasma plumes with rapidly evolving temperature and density gradients. These gradients can be measured using laser interferometric techniques that allow for the study of the plasma as the plume expands from the target surface and the temperature and density decrease. A systematic study of the temperature and density of aluminum, silicon, and carbon plasma plumes produced with a 2 TW/cm2 laser using spectroscopic, interferometric, fast imaging, and charge diagnostics will be presented. Carbon, aluminum, and silicon plumes are of interest because they are closely grouped on the periodic table but have very different material characteristics. Temporally and spatially resolved data was collected to characterize the evolution of the plasma in the plume. To probe the plasmas produced from these materials, optical spectroscopy was employed to identify and measure the temperature of the coexisting neutral and ionized atomic and molecular species. A Mach-Zehnder interferometer was employed to measure electron density. ICCD imaging and shadowgraphy were used to image the plume dynamics. A comparison of plasma evolution for each element will also be presented and will provide data to benchmark plasma codes. This work was supported by the University of Nevada, Reno, the U.S. DOE /NNSA Cooperative Agreement No. DE-NA0002075, and National Securities Technologies, LLC under Contract No. DE-AC52-06NA25946/Subcontract No. 165819.

  5. Lightning NOx influence on large-scale NOy and O3 plumes observed over the northern mid-latitudes

    Directory of Open Access Journals (Sweden)

    Alicia Gressent

    2014-11-01

    Full Text Available This paper describes the NOy plumes originating from lightning emissions based on 4 yr (2001–2005 of MOZAIC measurements in the upper troposphere of the northern mid-latitudes, together with ground- and space-based observations of lightning flashes and clouds. This analysis is primarily for the North Atlantic region where the MOZAIC flights are the most frequent and for which the measurements are well representative in space and time. The study investigates the influence of lightning NOx (LNOx emissions on large-scale (300–2000 km plumes (LSPs of NOy. One hundred and twenty seven LSPs (6% of the total MOZAIC NOy dataset have been attributed to LNOx emissions. Most of these LSPs were recorded over North America and the Atlantic mainly in spring and summer during the maximum lightning activity occurrence. The majority of the LSPs (74% is related to warm conveyor belts and extra-tropical cyclones originating from North America and entering the intercontinental transport pathway between North America and Europe, leading to a negative (positive west to east NOy (O3 zonal gradient with −0.4 (+18 ppbv difference during spring and −0.6 (+14 ppbv difference in summer. The NOy zonal gradient can correspond to the mixing of the plume with the background air. On the other hand, the O3 gradient is associated with both mixing of background air and with photochemical production during transport. Such transatlantic LSPs may have a potential impact on the European pollution. The remaining sampled LSPs are related to mesoscale convection over Western Europe and the Mediterranean Sea (18% and to tropical convection (8%.

  6. Dynamic Data-Driven UAV Network for Plume Characterization

    Science.gov (United States)

    2016-05-23

    AFRL-AFOSR-VA-TR-2016-0203 Dynamic Data-Driven UAV Network for Plume Characterization Kamran Mohseni UNIVERSITY OF FLORIDA Final Report 05/23/2016...AND SUBTITLE Dynamic Data-Driven UAV Network for Plume Characterization 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0090 5c.  PROGRAM ELEMENT...studied a dynamic data driven (DDD) approach to operation of a heterogeneous team of unmanned aerial vehicles ( UAVs ) or micro/miniature aerial

  7. An experimental study on the near-source region of lazy turbulent plumes

    Science.gov (United States)

    Ciriello, Francesco; Hunt, Gary R.

    2017-11-01

    The near-source region of a `lazy' turbulent buoyant plume issuing from a circular source is examined for source Richardson numbers in the range of 101 to 107. New data is acquired for the radial contraction and streamwise variation of volume flux through an experimental programme of dye visualisations and particle image velocimetry. This data reveals the limited applicability of traditional entrainment laws used in integral modelling approaches for the description of the near-source region for these source Richardson numbers. A revised entrainment function is proposed, based on which we introduce a classification of plume behaviour whereby the degree of `laziness' may be expressed in terms of the excess dilution that occurs compared to a `pure' constant Richardson number plume. The increased entrainment measured in lazy plumes is attributed to Rayleigh-Taylor instabilities developing along the contraction of the plume which promote the additional engulfment of ambient fluid into the plume. This work was funded by an EPSRC Industial Case Award sponsored by Dyson Technology Ltd. Special thanks go to the members of the Dyson Environmental Control Group that regularly visit us in Cambridge for discussions about our work.

  8. Prediction of fluctuating pressure environments associated with plume-induced separated flow fields

    Science.gov (United States)

    Plotkin, K. J.

    1973-01-01

    The separated flow environment induced by underexpanded rocket plumes during boost phase of rocket vehicles has been investigated. A simple semi-empirical model for predicting the extent of separation was developed. This model offers considerable computational economy as compared to other schemes reported in the literature, and has been shown to be in good agreement with limited flight data. The unsteady pressure field in plume-induced separated regions was investigated. It was found that fluctuations differed from those for a rigid flare only at low frequencies. The major difference between plume-induced separation and flare-induced separation was shown to be an increase in shock oscillation distance for the plume case. The prediction schemes were applied to PRR shuttle launch configuration. It was found that fluctuating pressures from plume-induced separation are not as severe as for other fluctuating environments at the critical flight condition of maximum dynamic pressure.

  9. Long-term bioremediation of a subsurface plume in silty soil

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.

    2000-01-01

    In northern Virginia, a loss from a tank farm has produced two plumes, containing about 200,000 gal of diesel fuel, jet-A fuel, and gasoline. Evidence suggests that the longest part of the contamination plume moved to its present length of 2,500 ft in less than 5 years. Since natural biodegradation would require about 2,500 years to reduce the hydrocarbon contamination to the remediation endpoints, other methods have been considered. Excavation of the plumes would take an estimated 5 years. However, the tank farm is surrounded by commercial buildings and expensive homes, and many of these buildings would have to be removed to reach the plumes. Enhanced natural bioremediation would require about 200 years at a start-up cost of about $1 million dollars and recurring costs of approximately $500,000/year. Infiltration galleries and enhanced subsurface permeability could reduce the remediation time to as little as 20 years

  10. Wildfire simulation using a chemically-reacting plume in a crossflow

    Science.gov (United States)

    Breidenthal, Robert; Alvarado, Travis; Potter, Brian

    2010-11-01

    Water tunnel experiments reveal the flame length of a chemically-reacting plume in a crossflow. Salt water containing a pH indicator and a base is slowly injected from above into the test section of a water tunnel containing an acidic solution. The flame length is measured optically as a function of the buoyancy flux, crossflow speed, and volume equivalence ratio of the chemical reaction. Based on earlier work of Broadwell with the transverse jet, a simple dilution model predicts the flame length of the transverse plume. The plume observations are in accord with the model. As with the jet, there is a minimum in the flame length of the plume at a transition between two self-similar regimes, corresponding to the formation of a pair of counter-rotating vortices at a certain crossflow speed. At the transition, there is a maximum in the entrainment and mixing rates. In an actual wildfire with variable winds, this transition may correspond to a dangerous condition for firefighters.

  11. Infrared optical properties of a coal-fired power plant plume

    International Nuclear Information System (INIS)

    Stearns, L.P.; Pueschel, R.F.

    1983-01-01

    Infrared measurements in the 8--14-μm spectral region were made of two coal-fired power plant plumes and area haze in the Four Corners region of New Mexico from 1 to 7 Nov. 1980. The layer tranmittance, optical depth, and volume extinction coefficient derived from measurements on four nonconsecutive days show the effects of the plumes on the IR optical properties of the atmosphere. The average contribution of the plume alone to the IR extinction coefficient was 74% at the Four Corners plant; the background haze contributed 7--11%. More efficient particulate emission control at the San Juan power plant reduced the average contribution of its plume to 57% of the extinction coefficient. The haze contributed an average of 16%. The results show an increase with time of the haze bulk extinction coefficient during a persistent anticyclonic synoptic situation. Extinction coefficients of the haze showed a linearity with particulate loading, which led to estimates of IR volume extinctions of the free troposphre from aerosol measurements

  12. A Monte Carlo simulation method for assessing biotransformation effects on groundwater fuel hydrocarbon plume lengths

    International Nuclear Information System (INIS)

    McNab, W.W. Jr.

    2000-01-01

    Biotransformation of dissolved groundwater hydrocarbon plumes emanating from leaking underground fuel tanks should, in principle, result in plume length stabilization over relatively short distances, thus diminishing the environmental risk. However, because the behavior of hydrocarbon plumes is usually poorly constrained at most leaking underground fuel tank sites in terms of release history, groundwater velocity, dispersion, as well as the biotransformation rate, demonstrating such a limitation in plume length is problematic. Biotransformation signatures in the aquifer geochemistry, most notably elevated bicarbonate, may offer a means of constraining the relationship between plume length and the mean biotransformation rate. In this study, modeled plume lengths and spatial bicarbonate differences among a population of synthetic hydrocarbon plumes, generated through Monte Carlo simulation of an analytical solute transport model, are compared to field observations from six underground storage tank (UST) sites at military bases in California. Simulation results indicate that the relationship between plume length and the distribution of bicarbonate is best explained by biotransformation rates that are consistent with ranges commonly reported in the literature. This finding suggests that bicarbonate can indeed provide an independent means for evaluating limitations in hydrocarbon plume length resulting from biotransformation. (Author)

  13. Marine snow, organic solute plumes, and optimal chemosensory behavior of bacteria

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jackson, G.A.

    2001-01-01

    Leaking organic solutes form an elongated plume in the wake of a sinking aggregate. These solutes may both be assimilated by suspended bacteria and guide bacteria with chemokinetic swimming behavior toward the aggregate. We used modifications of previously published models of the flow and concent......Leaking organic solutes form an elongated plume in the wake of a sinking aggregate. These solutes may both be assimilated by suspended bacteria and guide bacteria with chemokinetic swimming behavior toward the aggregate. We used modifications of previously published models of the flow...... behavior was used to examine the potential contribution of aggregate-generated solute plumes for water column bacteria] production. Despite occupying only a small volume fraction, the plumes may provide important growth habitats for free bacteria and account for a significant proportion of water column...

  14. Real-time, high frequency (1 Hz), in situ measurement of HCl and HF gases in volcanic plumes with a novel cavity-enhanced, laser-based instrument

    Science.gov (United States)

    Kelly, P. J.; Sutton, A. J.; Elias, T.; Kern, C.; Clor, L. E.; Baer, D. S.

    2017-12-01

    Primary magmatic halogen-containing gases (HCl, HF, HBr, HI in characteristic order of abundance) are of great interest for volcano monitoring and research because, in general, they are more soluble in magma than other commonly-monitored volcanic volatiles (e.g. CO2, SO2, H2S) and thereby can offer unique insights into shallow magmatic processes. Nevertheless, difficulties in obtaining observations of primary volcanic halogens in gas plumes with traditional methods (e.g. direct sampling, Open-Path Fourier Transform Infrared spectroscopy, filter packs) have limited the number of observations reported worldwide, especially from explosive arc volcanoes. With this in mind, the USGS and Los Gatos Research, Inc. collaborated to adapt a commercially-available industrial in situ HCl-HF analyzer for use in airborne and ground-based measurements of volcanic gases. The new, portable instrument is based around two near-IR tunable diode lasers and uses a vibration-tolerant, enhanced-cavity approach that is well-suited for rugged field applications and yields fast (1 Hz) measurements with a wide dynamic range (0 -2 ppm) and sub-ppb precision (1σ: HCl: <0.4 ppb; HF: <0.1 ppb). In spring 2017 we conducted field tests at Kīlauea Volcano, Hawaii, to benchmark the performance of the new instrument and to compare it with an accepted method for halogen measurements (OP-FTIR). The HCl-HF instrument was run in parallel with a USGS Multi-GAS to obtain in situ H2O-CO2-SO2-H2S-HCl-HF plume compositions. The results were encouraging and quasi-direct comparisons of the in situ and remote sensing instruments showed good agreement (e.g. in situ SO2/HCl = 72 vs. OP-FTIR SO2/HCl = 88). Ground-based and helicopter-based measurements made 0 - 12 km downwind from the vent (plume age 0 - 29 minutes) show that plume SO2/HCl ratios increase rapidly from 60 to 300 around the plume edges, possibly due to uptake of HCl onto aerosols.

  15. Sinking, merging and stationary plumes in a coupled chemotaxis-fluid model: a high-resolution numerical approach

    KAUST Repository

    Chertock, A.; Fellner, K.; Kurganov, A.; Lorz, A.; Markowich, P. A.

    2012-01-01

    examples, which illustrate (i) the formation of sinking plumes, (ii) the possible merging of neighbouring plumes and (iii) the convergence towards numerically stable stationary plumes. The examples with stable stationary plumes show how the surface

  16. The growth and decay of equatorial backscatter plumes

    Science.gov (United States)

    Tsunoda, R. T.

    1980-02-01

    During the past three years, a series of rocket experiments from the Kwajalein Atoll, Marshall Islands, were conducted to investigate the character of intense, scintillation-producing irregularities that occur in the nighttime equatorial ionosphere. Because the source mechanism of equatorial irregularities, believed to be the Rayleigh-Taylor instability, is analogous to that which generates plasma-density striations in a nuclear-induced environment, there is considerable interest in the underlying physics that controls the characteristics of these irregularities. A primary objective of ALTAIR investigations of equatorial irregularities is to seek an understanding of the underlying physics by establishing the relationship between meter-scale irregularities (detected by ALTAIR), and the large-scale plasma-density depletions (or 'bubbles') that contain the kilometer-scale, scintillation-producing irregularities. We describe the time evolution of backscatter 'plumes' produced by one meter equatorial field-aligned irregularities. Using ALTAIR, a fully steerable backscatter radar, to repeatedly map selected plumes, we characterize the dynamic behavior of plumes in terms of growth and a decay phase. Most of the observed characteristics are found to be consistent with equatorial-irregularity generation predicted by current theories of Rayleigh-Taylor and gradient-drift instabilities. However, other characteristics have been found that suggest key roles played by the eastward neutral wind and by altitude-modulation of the bottomside F layer in establishing the initial conditions for plume growth.

  17. Plume Characterization of a Laboratory Model 22 N GPIM Thruster via High-Frequency Raman Spectroscopy

    Science.gov (United States)

    Williams, George J.; Kojima, Jun J.; Arrington, Lynn A.; Deans, Matthew C.; Reed, Brian D.; Kinzbach, McKenzie I.; McLean, Christopher H.

    2015-01-01

    The Green Propellant Infusion Mission (GPIM) will demonstrate the capability of a green propulsion system, specifically, one using the monopropellant, AF-M315E. One of the risks identified for GPIM is potential contamination of sensitive areas of the spacecraft from the effluents in the plumes of AF-M315E thrusters. Plume characterization of a laboratory-model 22 N thruster via optical diagnostics was conducted at NASA GRC in a space-simulated environment. A high-frequency pulsed laser was coupled with an electron-multiplied ICCD camera to perform Raman spectroscopy in the near-field, low-pressure plume. The Raman data yielded plume constituents and temperatures over a range of thruster chamber pressures and as a function of thruster (catalyst) operating time. Schlieren images of the near-field plume enabled calculation of plume velocities and revealed general plume structure of the otherwise invisible plume. The measured velocities are compared to those predicted by a two-dimensional, kinetic model. Trends in data and numerical results are presented from catalyst mid-life to end-of-life. The results of this investigation were coupled with the Raman and Schlieren data to provide an anchor for plume impingement analysis presented in a companion paper. The results of both analyses will be used to improve understanding of the nature of AF-M315E plumes and their impacts to GPIM and other future missions.

  18. Observations of brine plumes below melting Arctic sea ice

    Directory of Open Access Journals (Sweden)

    A. K. Peterson

    2018-02-01

    Full Text Available In sea ice, interconnected pockets and channels of brine are surrounded by fresh ice. Over time, brine is lost by gravity drainage and flushing. The timing of salt release and its interaction with the underlying water can impact subsequent sea ice melt. Turbulence measurements 1 m below melting sea ice north of Svalbard reveal anticorrelated heat and salt fluxes. From the observations, 131 salty plumes descending from the warm sea ice are identified, confirming previous observations from a Svalbard fjord. The plumes are likely triggered by oceanic heat through bottom melt. Calculated over a composite plume, oceanic heat and salt fluxes during the plumes account for 6 and 9 % of the total fluxes, respectively, while only lasting in total 0.5 % of the time. The observed salt flux accumulates to 7.6 kg m−2, indicating nearly full desalination of the ice. Bulk salinity reduction between two nearby ice cores agrees with accumulated salt fluxes to within a factor of 2. The increasing fraction of younger, more saline ice in the Arctic suggests an increase in desalination processes with the transition to the new Arctic.

  19. Observations of brine plumes below melting Arctic sea ice

    Science.gov (United States)

    Peterson, Algot K.

    2018-02-01

    In sea ice, interconnected pockets and channels of brine are surrounded by fresh ice. Over time, brine is lost by gravity drainage and flushing. The timing of salt release and its interaction with the underlying water can impact subsequent sea ice melt. Turbulence measurements 1 m below melting sea ice north of Svalbard reveal anticorrelated heat and salt fluxes. From the observations, 131 salty plumes descending from the warm sea ice are identified, confirming previous observations from a Svalbard fjord. The plumes are likely triggered by oceanic heat through bottom melt. Calculated over a composite plume, oceanic heat and salt fluxes during the plumes account for 6 and 9 % of the total fluxes, respectively, while only lasting in total 0.5 % of the time. The observed salt flux accumulates to 7.6 kg m-2, indicating nearly full desalination of the ice. Bulk salinity reduction between two nearby ice cores agrees with accumulated salt fluxes to within a factor of 2. The increasing fraction of younger, more saline ice in the Arctic suggests an increase in desalination processes with the transition to the new Arctic.

  20. PILLARED ZEOLITES AMENDMENTS INFLUENCE FROM POLLUTED SOIL ON HEAVY METALS BIOACCUMULATION IN TOMATOES

    Directory of Open Access Journals (Sweden)

    SMARANDA MASU

    2007-05-01

    Full Text Available Due to anthropic activities, the presence of metals in polluted soils has effects on plants development and metals bioaccumulation into trophic levels. In this paper, were followed experiments regarding the tomatoes development into polluted soils with 43.4 – 58.4 mg Cd/kg d.s. and 500- 633 mg Pb/kg d.s. Nickel, zinc and copper content in soils are in the range of diffuse pollution values. Comparatively, an experiment was realized with polluted soils and amended with pillared zeolites. Pillared zeolites change metals distribution in soil fractions and their solubility. Tomato plants grew onto polluted soils, but did not present fruits. Tomatoes from polluted and amended soils presented fruits and metals in tissues (Zn  Cu  Ni. Zinc concentration was five times greater then Ni. Fruits do not accumulate cadmium and lead.

  1. Deposition and solubility of airborne metals to four plant species grown at varying distances from two heavily trafficked roads in London

    International Nuclear Information System (INIS)

    Peachey, C.J.; Sinnett, D.; Wilkinson, M.; Morgan, G.W.; Freer-Smith, P.H.; Hutchings, T.R.

    2009-01-01

    In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility. - High density traffic resulted in elevated metal concentrations on vegetation, which were related to distance from road and plant species.

  2. Deposition and solubility of airborne metals to four plant species grown at varying distances from two heavily trafficked roads in London

    Energy Technology Data Exchange (ETDEWEB)

    Peachey, C.J. [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Sinnett, D., E-mail: danielle.sinnett@forestry.gsi.gov.u [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Wilkinson, M., E-mail: matthew.wilkinson@forestry.gsi.gov.u [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Morgan, G.W., E-mail: geoff.morgan@forestry.gsi.gov.u [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Freer-Smith, P.H., E-mail: peter.freer-smith@forestry.gsi.gov.u [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom); Hutchings, T.R., E-mail: tony.hutchings@forestry.gsi.gov.u [Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH (United Kingdom)

    2009-08-15

    In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility. - High density traffic resulted in elevated metal concentrations on vegetation, which were related to distance from road and plant species.

  3. Naval Weapons Center Plume Radar Frequency Interference Code

    Science.gov (United States)

    1982-10-01

    ppm sodium. Both equilibrium and finite rate chemistry during the expansion from the chamber were tried as initial conditions for the plume. In...was too large. The difference between the.e two sets of initial conditions diminished downstream as the chemistry in the plume mixing region began to...Rerkirre Arvliral I Comirlnrnde!- ir.C h ic 1. tVS. Pacific Hice ((Code 3251 1 Corimu tinde r. ’n, r-d I leer. Pearl I atar I Coimniaide r. Sevent

  4. Automated recognition and tracking of aerosol threat plumes with an IR camera pod

    Science.gov (United States)

    Fauth, Ryan; Powell, Christopher; Gruber, Thomas; Clapp, Dan

    2012-06-01

    Protection of fixed sites from chemical, biological, or radiological aerosol plume attacks depends on early warning so that there is time to take mitigating actions. Early warning requires continuous, autonomous, and rapid coverage of large surrounding areas; however, this must be done at an affordable cost. Once a potential threat plume is detected though, a different type of sensor (e.g., a more expensive, slower sensor) may be cued for identification purposes, but the problem is to quickly identify all of the potential threats around the fixed site of interest. To address this problem of low cost, persistent, wide area surveillance, an IR camera pod and multi-image stitching and processing algorithms have been developed for automatic recognition and tracking of aerosol plumes. A rugged, modular, static pod design, which accommodates as many as four micro-bolometer IR cameras for 45deg to 180deg of azimuth coverage, is presented. Various OpenCV1 based image-processing algorithms, including stitching of multiple adjacent FOVs, recognition of aerosol plume objects, and the tracking of aerosol plumes, are presented using process block diagrams and sample field test results, including chemical and biological simulant plumes. Methods for dealing with the background removal, brightness equalization between images, and focus quality for optimal plume tracking are also discussed.

  5. A stable isotope approach for source apportionment of chlorinated ethene plumes at a complex multi-contamination events urban site

    Science.gov (United States)

    Nijenhuis, Ivonne; Schmidt, Marie; Pellegatti, Eleonora; Paramatti, Enrico; Richnow, Hans Hermann; Gargini, Alessandro

    2013-10-01

    The stable carbon isotope composition of chlorinated aliphatic compounds such as chlorinated methanes, ethanes and ethenes was examined as an intrinsic fingerprint for apportionment of sources. A complex field site located in Ferrara (Italy), with more than 50 years history of use of chlorinated aliphatic compounds, was investigated in order to assess contamination sources. Several contamination plumes were found in a complex alluvial sandy multi-aquifer system close to the river Po; sources are represented by uncontained former industrial and municipal dump sites as well as by spills at industrial areas. The carbon stable isotope signature allowed distinguishing 2 major sources of contaminants. One source of chlorinated aliphatic contaminants was strongly depleted in 13C (-40‰ which is commonly observed in recent production of chlorinated solvents. The degradation processes in the plumes could be traced interpreting the isotope enrichment and depletion of parent and daughter compounds, respectively. We demonstrate that, under specific production conditions, namely when highly chlorinated ethenes are produced as by-product during chloromethanes production, 13C depleted fingerprinting of contaminants can be obtained and this can be used to track sources and address the responsible party of the pollution in urban areas.

  6. Morphology of the Zambezi River plume in the Sofala Bank ...

    African Journals Online (AJOL)

    In this paper, hydrographic data collected in the vicinity of the Zambezi River plume between 2004-2007 is discussed alongside historical data to infer the plume morphology. The sampling plan called for 73 CTD stations that were interspersed with sampling of shrimp recruitment. Satellite-derived wind speed and river ...

  7. Controls of Plume Dispersal at the Slow Spreading Mid-Atlantic Ridge

    Science.gov (United States)

    Walter, M.; Mertens, C.; Koehler, J.; Sueltenfuss, J.; Rhein, M.; Keir, R. S.; Schmale, O.; Schneider v. Deimling, J.; German, C. R.; Yoerger, D. R.; Baker, E. T.

    2011-12-01

    The slow-spreading Mid-Atlantic Ridges hosts a multitude of different types of hydrothermal systems. Here, we compare the fluxes and the plume dispersal at three high temperature sites located in very diverse settings at comparable depths (~3000m): The recently discovered sites Turtle Pits, and Nibelungen on the southern MAR, and the Logatchev field in the North Atlantic. Plume mapping for these sites on cruises between 2004 and 2009 consisted of CTD Towyo-, Yoyo,- and station work, including velocity profiling, as well as water sampling for analysis of trace gases (CH4, H2, 3He/4He) and metals; temperature measurements and fluid sampling at the vent sites were carried out with an ROV. The aim of this work is to gain a better understanding of how the setting of a vent site affects the dispersal of the particle plume, and what means can be used to infer possible locations of vent sites based on the hydrographic properties and plume observations, using high resolution bathymetric mapping and hydrographic information. The ultramafic-hosted Nibelungen site (8°18'S) consists of a single active smoking crater, along with several extinct smokers, which is located off-axis south of a non-transform offset. The setting is characterized by rugged topography, favorable for the generation of internal tides, internal wave breaking, and vertical mixing. Elevated mixing with turbulent diffusivities Kρ up to 0.1 m2 s-1, 3 to 4 orders of magnitude higher than open ocean values, was observed close to the vent site. The mixing as well as the flow field exhibited a strong tidal cycle; the plume dispersal is thus dominated by the fast and intermittent vertical exchange and characterized by small scale spatial and temporal variability. The Turtle Pits vent fields (4°48'S) are located on a sill in a north-south orientated rift valley. The site consists of three (known) high temperature fields: Turtle Pits, Comfortless Cove, and Red Lion. The particle plume is confined to the rift

  8. Guided Seismic Waves: Possible Diagnostics for Hot Plumes in the Mantle

    Science.gov (United States)

    Evans, J. R.; Julian, B. R.; Foulger, G. R.

    2005-12-01

    Seismic waves potentially provide by far the highest resolution view of the three-dimensional structure of the mantle, and the hope of detecting wave-speed anomalies caused by hot or compositionally buoyant mantle plumes has been a major incentive to the development of tomographic seismic techniques. Seismic tomography is limited, however, by the uneven geographical distribution of earthquakes and seismometers, which can produce artificial tomographic wave-speed anomalies that are difficult to distinguish from real structures in the mantle. An alternate approach may be possible, because hot plumes and possibly some compositional upwellings would have low seismic-wave speeds and would act as efficient waveguides over great depth ranges in the mantle. Plume-guided waves would be little affected by bends or other geometric complexities in the waveguides (analogously to French horns and fiber-optic cables), and their dispersion would make them distinctive on seismograms and would provide information on the size and structure of the waveguide. The main unanswered question is whether guided waves in plumes could be excited sufficiently to be observable. Earthquakes do not occur in the deep mantle, but at least two other possible sources of excitation can be imagined: (1) shallow earthquakes at or near plume-fed hotspots; and (2) coupling of plume-guided waves to seismic body waves near the bottom of the mantle. In the first case, downward-traveling guided waves transformed to seismic body waves at the bottom of the waveguide would have to be detected at teleseismic distances. In the second case, upward-traveling guided waves generated by teleseismic body waves would be detected on seismometers at hotspots. Qualitative reasoning based on considerations of reciprocity suggests that the signals in these two situations should be similar in size and appearance. The focusing of seismic core phases at caustics would amplify plume waves excited by either mechanism (1) or (2) at

  9. Radiative modeling and characterization of aerosol plumes hyper-spectral imagery

    International Nuclear Information System (INIS)

    Alakian, A.

    2008-03-01

    This thesis aims at characterizing aerosols from plumes (biomass burning, industrial discharges, etc.) with hyper-spectral imagery. We want to estimate the optical properties of emitted particles and also their micro-physical properties such as number, size distribution and composition. To reach our goal, we have built a forward semi-analytical model, named APOM (Aerosol Plume Optical Model), which allows to simulate the radiative effects of aerosol plumes in the spectral range [0,4-2,5 μm] for nadir viewing sensors. Mathematical formulation and model coefficients are obtained from simulations performed with the radiative transfer code COMANCHE. APOM is assessed on simulated data and proves to be accurate with modeling errors between 1% and 3%. Three retrieval methods using APOM have been developed: L-APOM, M-APOM and A-APOM. These methods take advantage of spectral and spatial dimensions in hyper-spectral images. L-APOM and M-APOM assume a priori knowledge on particles but can estimate their optical and micro-physical properties. Their performances on simulated data are quite promising. A-APOM method does not require any a priori knowledge on particles but only estimates their optical properties. However, it still needs improvements before being usable. On real images, inversion provides satisfactory results for plumes above water but meets some difficulties for plumes above vegetation, which underlines some possibilities of improvement for the retrieval algorithm. (author)

  10. N Reactor thermal plume characterization during Pu-only mode of operation

    Energy Technology Data Exchange (ETDEWEB)

    Ecker, R.M.; Thompson, F.L.; Whelan, G.

    1983-04-01

    Pacific Northwest Laboratories (PNL) performed field and modeling studies -from March 1982 through June 1983 to characterize the thermal plume from the N Reactor heated water outfall while the N Reactor operated in the Pu-only mode. Part 1 of this report deals with the field studies conducted to characterize the N Reactor thermal plume while in the Pu-only mode of operation. It includes a description of the study area, a description of field tasks and procedures, and data collection results and discussion. Part 2 describes the computer simulation of the thermal plume under different flow conditions and the calibration of the model used. It includes a description of the computer model and the assumptions on which it is based, a presentation of the input data used in this application, and a discussion of modeling results. Because the field studies were restricted by the NPOES permit variance to the spring months when high Columbia River flows prevail the mathematical modeling of the N Reactor thermal plume while the reactor operates in the Pu-only mode is instrumental in characterizing the plume during low Columbia River flows.

  11. Merits of a Scenario Approach in Dredge Plume Modelling

    DEFF Research Database (Denmark)

    Pedersen, Claus; Chu, Amy Ling Chu; Hjelmager Jensen, Jacob

    2011-01-01

    Dredge plume modelling is a key tool for quantification of potential impacts to inform the EIA process. There are, however, significant uncertainties associated with the modelling at the EIA stage when both dredging methodology and schedule are likely to be a guess at best as the dredging...... contractor would rarely have been appointed. Simulation of a few variations of an assumed full dredge period programme will generally not provide a good representation of the overall environmental risks associated with the programme. An alternative dredge plume modelling strategy that attempts to encapsulate...... uncertainties associated with preliminary dredging programmes by using a scenario-based modelling approach is presented. The approach establishes a set of representative and conservative scenarios for key factors controlling the spill and plume dispersion and simulates all combinations of e.g. dredge, climatic...

  12. Lethal action of soluble metallic salts on fishes

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, K E

    1927-01-01

    A study of pollution of Welsh rivers by lead-mine effluents revealed the fact that fishes were killed by the action of soluble salts of lead, which proved lethal at concentrations so low as pb i : 3,000,000. A physiological investigation of the action of lead-salts revealed the following facts: the action does not correspond to the normal toxic type. The graph of survival-times in different concentrations closely follows the equation: K = i/t log i/conc. The speed of the reaction is dependent upon the total quantity of metallic ion present, as well as upon the actual concentrations. The speed of the reaction varies in inverse relation to the size and weight of fishes employed. The most marked symptom is the formation of a film over gills and skin, by interaction of the metallic ion with a mucus-constituent. Death by suffocation is the final result. Where insufficient lead ion is present, the film is shed off, and complete recovery takes place. The speed of the reaction varies in direct relation to the temperature. Chemical analysis of residues shows that no trace of metallic ion penetrates into the body itself. The action is thus held to be purely external in process, chemical in type, and mechanical in effect; i.e., it is not a toxic action in the ordinary sense of the term. The action of soluble salts of zinc, iron, copper, cadmium, and mercury is shown to follow the same law as that of lead. Attention is directed to the economic importance of the facts, in connection with the pollution of rivers.

  13. Cross-flow shearing effects on the trajectory of highly buoyant bent-over plumes

    Science.gov (United States)

    Tohidi, Ali; Kaye, Nigel Berkeley; Gollner, Michael J.

    2017-11-01

    The dynamics of highly buoyant plumes in cross-flow is ubiquitous throughout both industrial and environmental phenomena. The rise of smoke from a chimney, wastewater discharge into river currents, and dispersion of wildfire plumes are only a few instances. There have been many previous studies investigating the behavior of jets and highly buoyant plumes in cross-flow. So far, however, very little attention has been paid to the role of shearing effects in the boundary layer on the plume trajectory, particularly on the rise height. Numerical simulations and dimensional analysis are conducted to characterize the near- and far-field behavior of a highly buoyant plume in a boundary layer cross-flow. The results show that shear in the cross-flow leads to large differences in the rise height of the plume in relation to a uniform cross-flow, especially at far-field. This material is based upon work supported by the National Science Foundation under Grant No.1200560. Any opinions, findings, and conclusions or recommendations expressed in the material are of the authors and do not necessarily reflect the views of NSF.

  14. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO2(cr)

    International Nuclear Information System (INIS)

    Rai, Dhanpat; Kitamura, Akira; Rosso, Kevin M.; Sasaki, Takayuki; Kobayashi, Taishi

    2016-01-01

    Solubility studies were conducted with HfO 2 (cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg -1 . These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO 2 (am) suspensions to 90 C to ascertain whether the HfO 2 (am) converts to HfO 2 (cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO 2 (cr) contains a small fraction of less crystalline, but not amorphous, material [HfO 2 (lcr)] and this, rather than the HfO 2 (cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log 10 K 0 values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO 2 (lcr)[HfO 2 (lcr) + 2H 2 O ↔ Hf 4+ + 4OH - ]. The log 10 of the solubility product of HfO 2 (cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  15. The effect of a tall tower on flow and dispersion through a model urban neighborhood: part 2. Pollutant dispersion.

    Science.gov (United States)

    Brixey, Laurie A; Heist, David K; Richmond-Bryant, Jennifer; Bowker, George E; Perry, Steven G; Wiener, Russell W

    2009-12-01

    This article is the second in a two-paper series presenting results from wind tunnel and computational fluid dynamics (CFD) simulations of flow and dispersion in an idealized model urban neighborhood. Pollutant dispersion results are presented and discussed for a model neighborhood that was characterized by regular city blocks of three-story row houses with a single 12-story tower located at the downwind edge of one of these blocks. The tower had three significant effects on pollutant dispersion in the surrounding street canyons: drawing the plume laterally towards the tower, greatly enhancing the vertical dispersion of the plume in the wake of the tower, and significantly decreasing the residence time of pollutants in the wake of the tower. In the wind tunnel, tracer gas released in the avenue lee of the tower, but several blocks away laterally, was pulled towards the tower and lifted in the wake of the tower. The same lateral movement of the pollutant was seen in the next avenue, which was approximately 2.5 tower heights downwind of the tower. The tower also served to ventilate the street canyon directly in its wake more rapidly than the surrounding areas. This was evidenced by CFD simulations of concentration decay where the residence time of pollutants lee of the 12-story tower was found to be less than half the residence time behind a neighboring three-story building. This same phenomenon of rapid vertical dispersion lee of a tower among an array of smaller buildings was also demonstrated in a separate set of wind tunnel experiments using an array of cubical blocks. A similar decrease in the residence time was observed when the height of one block was increased.

  16. Experimental study of starting plumes simulating cumulus cloud flows in the atmosphere

    Science.gov (United States)

    Subrahmanyam, Duvvuri; Sreenivas, K. R.; Bhat, G. S.; Diwan, S. S.; Narasimha, Roddam

    2009-11-01

    Turbulent jets and plumes subjected to off-source volumetric heating have been studied experimentally and numerically by Narasimha and co-workers and others over the past two decades. The off-source heating attempts to simulate the latent heat release that occurs in cumulus clouds on condensation of water vapour. This heat release plays a crucial role in determining the overall cloud shape among other things. Previous studies investigated steady state jets and plumes that had attained similarity upstream of heat injection. A better understanding and appreciation of the fluid dynamics of cumulus clouds should be possible by study of starting plumes. Experiments have been set up at JNCASR (Bangalore) using experimental techniques developed previously but incorporating various improvements. Till date, experiments have been performed on plumes at Re of 1000 and 2250, with three different heating levels in each case. Axial sections of the flow have been studied using standard PLIF techniques. The flow visualization provides us with data on the temporal evolution of the starting plume. It is observed that the broad nature of the effect of off-source heating on the starting plumes is generally consistent with the results obtained previously on steady state flows. More complete results and a critical discussion will be presented at the upcoming meeting.

  17. Acoustical Survey of Methane Plumes on North Hydrate Ridge: Constraining Temporal and Spatial Characteristics.

    Science.gov (United States)

    Kannberg, P. K.; Trehu, A. M.

    2008-12-01

    While methane plumes associated with hydrate formations have been acoustically imaged before, little is known about their temporal characteristics. Previous acoustic surveys have focused on determining plume location, but as far as we know, multiple, repeated surveys of the same plume have not been done prior to the survey presented here. In July 2008, we acquired sixteen identical surveys within 19 hours over the northern summit of Hydrate Ridge in the Cascadia accretionary complex using the onboard 3.5 and 12 kHz echosounders. As in previous studies, the plumes were invisible to the 3.5 kHz echosounder and clearly imaged with 12 kHz. Seafloor depth in this region is ~600 m. Three distinct plumes were detected close to where plumes were located by Heeschen et al. (2003) a decade ago. Two of the plumes disappeared at ~520 m water depth, which is the depth of the top of the gas hydrate stability as determined from CTD casts obtained during the cruise. This supports the conclusion of Heeschen et al. (2003) that the bubbles are armored by gas hydrate and that they dissolve in the water column when they leave the hydrate stability zone. One of the plumes near the northern summit, however, extended through this boundary to at least 400 m (the shallowest depth recorded). A similar phenomenon was observed in methane plumes in the Gulf of Mexico, where the methane was found to be armored by an oil skin. In addition to the steady plumes, two discrete "burps" were observed. One "burp" occurred approximately 600 m to the SSW of the northern summit. This was followed by a second strong event 300m to the north an hour later. To evaluate temporal and spatial patterns, we summed the power of the backscattered signal in different depth windows for each survey. We present the results as a movie in which the backscatter power is shown in map view as a function of time. The surveys encompassed two complete tidal cycles, but no correlation between plume location or intensity and tides

  18. Thermal turbulent convection: thermal plumes and fluctuations

    International Nuclear Information System (INIS)

    Gibert, M.

    2007-10-01

    In this study we investigate the phenomenon of thermal turbulent convection in new and unprecedented ways. The first system we studied experimentally is an infinite vertical channel, where a constant vertical mean gradient of temperature exists. Inside this channel the average mass flux is null. The results obtained from our measurements reveal that the flow is mainly inertial; indeed the dissipative coefficients (here the viscosity) play a role only to define a coherence length L. This length is the distance over which the thermal plumes can be considered as 'free falling' objects. The horizontal transport, of heat and momentum, is entirely due to fluctuations. The associated 'mixing length' is small compared to the channel width. In the other hand, the vertical heat transport is due to coherent structures: the heat plumes. Those objects were also investigated in a Lagrangian study of the flow in the bulk of a Rayleigh-Benard cell. The probe, which has the same density as the fluid used in this experiment, is a sphere of 2 cm in diameter with embarked thermometers and radio-emitter. The heat plumes transport it, which allows a statistical study of such objects. (author)

  19. Ozone Depletion in Tropospheric Volcanic Plumes: From Halogen-Poor to Halogen-Rich Emissions

    Directory of Open Access Journals (Sweden)

    Tjarda J. Roberts

    2018-02-01

    Full Text Available Volcanic halogen emissions to the troposphere undergo a rapid plume chemistry that destroys ozone. Quantifying the impact of volcanic halogens on tropospheric ozone is challenging, only a few observations exist. This study presents measurements of ozone in volcanic plumes from Kīlauea (HI, USA, a low halogen emitter. The results are combined with published data from high halogen emitters (Mt Etna, Italy; Mt Redoubt, AK, USA to identify controls on plume processes. Ozone was measured during periods of relatively sustained Kīlauea plume exposure, using an Aeroqual instrument deployed alongside Multi-Gas SO2 and H2S sensors. Interferences were accounted for in data post-processing. The volcanic H2S/SO2 molar ratio was quantified as 0.03. At Halema‘uma‘u crater-rim, ozone was close to ambient in the emission plume (at 10 ppmv SO2. Measurements in grounding plume (at 5 ppmv SO2 about 10 km downwind of Pu‘u ‘Ō‘ō showed just slight ozone depletion. These Kīlauea observations contrast with substantial ozone depletion reported at Mt Etna and Mt Redoubt. Analysis of the combined data from these three volcanoes identifies the emitted Br/S as a strong but non-linear control on the rate of ozone depletion. Model simulations of the volcanic plume chemistry highlight that the proportion of HBr converted into reactive bromine is a key control on the efficiency of ozone depletion. This underlines the importance of chemistry in the very near-source plume on the fate and atmospheric impacts of volcanic emissions to the troposphere.

  20. Ship exhaust gas plume cooling

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Neele, P.P.

    2004-01-01

    The exhaust gas plume is an important and sometimes dominating contributor to the infrared signature of ships. Suppression of the infrared ship signatures has been studied by TNO for the Royal Netherlands Navy over considerable time. This study deals with the suppression effects, which can be

  1. Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

    Science.gov (United States)

    Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2008-12-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

  2. Numerical study on similarity of plume infrared radiation between reduced-scale solid rocket motors

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoying

    2016-08-01

    Full Text Available This study seeks to determine the similarities in plume radiation between reduced and full-scale solid rocket models in ground test conditions through investigation of flow and radiation for a series of scale ratios ranging from 0.1 to 1. The radiative transfer equation (RTE considering gas and particle radiation in a non-uniform plume has been adopted and solved by the finite volume method (FVM to compute the three dimensional, spectral and directional radiation of a plume in the infrared waveband 2–6 μm. Conditions at wavelengths 2.7 μm and 4.3 μm are discussed in detail, and ratios of plume radiation for reduced-scale through full-scale models are examined. This work shows that, with increasing scale ratio of a computed rocket motor, area of the high-temperature core increases as a 2 power function of the scale ratio, and the radiation intensity of the plume increases with 2–2.5 power of the scale ratio. The infrared radiation of plume gases shows a strong spectral dependency, while that of Al2O3 particles shows spectral continuity of gray media. Spectral radiation intensity of a computed solid rocket plume’s high temperature core increases significantly in peak radiation spectra of plume gases CO and CO2. Al2O3 particles are the major radiation component in a rocket plume. There is good similarity between contours of plume spectral radiance from different scale models of computed rockets, and there are two peak spectra of radiation intensity at wavebands 2.7–3.0 μm and 4.2–4.6 μm. Directed radiation intensity of the entire plume volume will rise with increasing elevation angle.

  3. Space Shuttle main engine OPAD: The search for a hardware enhanced plume

    Science.gov (United States)

    Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

    1993-01-01

    The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

  4. Space Shuttle main engine OPAD: The search for a hardware enhanced plume

    Science.gov (United States)

    Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

    1993-11-01

    The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

  5. Abalone water-soluble matrix for self-healing biomineralization of tooth defects.

    Science.gov (United States)

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53wt% the abalone water-soluble protein (AWSPro) and 2.04wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. IASI measurements of reactive trace species in biomass burning plumes

    Directory of Open Access Journals (Sweden)

    P.-F. Coheur

    2009-08-01

    Full Text Available This work presents observations of a series of short-lived species in biomass burning plumes from the Infrared Atmospheric Sounding Interferometer (IASI, launched onboard the MetOp-A platform in October 2006. The strong fires that have occurred in the Mediterranean Basin – and particularly Greece – in August 2007, and those in Southern Siberia and Eastern Mongolia in the early spring of 2008 are selected to support the analyses. We show that the IASI infrared spectra in these fire plumes contain distinctive signatures of ammonia (NH3, ethene (C2H4, methanol (CH3OH and formic acid (HCOOH in the atmospheric window between 800 and 1200 cm−1, with some noticeable differences between the plumes. Peroxyacetyl nitrate (CH3COOONO2, abbreviated as PAN was also observed with good confidence in some plumes and a tentative assignment of a broadband absorption spectral feature to acetic acid (CH3COOH is made. For several of these species these are the first reported measurements made from space in nadir geometry. The IASI measurements are analyzed for plume height and concentration distributions of NH3, C2H4 and CH3OH. The Greek fires are studied in greater detail for the days associated with the largest emissions. In addition to providing information on the spatial extent of the plume, the IASI retrievals allow an estimate of the total mass emissions for NH3, C2H4 and CH3OH. Enhancement ratios are calculated for the latter relative to carbon monoxide (CO, giving insight in the chemical processes occurring during the transport, the first day after the emission.

  7. Microbiology, Redox and Contaminat Fate in the Grindsted Landfill Leachate Plume - A Summary of 25 Years of work

    Science.gov (United States)

    Christensen, T. H.

    2001-05-01

    The contamination by leachate of the upper aquifer at the Grindsted Landfill (Denmark) stretches about 300 m downgradient from the landfill. The plume has been described with respect to water chemistry, sediment chemistry, pollutant distribution, microbial counts, PLFA and redox rates determined by unamended bioassays. This presentation summaries the findings and discusses unanswered questions. The landfill was active from 1930 to the mid 1970 and has no engineered leachate collection system. Leachate from municipal as well as from industrial waste has entered the aquifer for more than thirty years. The redox conditions change from strongly anaerobic (methanogenic, sulfate reducing, iron reducing) close to the landfill over manganese reduction and denitrification to aerobic conditions in the outskirts of the plume The redox conditions were determined from groundwater sample composition, hydrogen concentrations and sediment chemistry. The plume showed strong attenuation of aromatic compounds within the first 100 m downgradient of the landfill. Degradation experiments (batch, in-situ testers, long term field injection experiments) could not fully document degradation of all the compounds. MPN-measurements of methanogens, sulfate-reducers, iron-reducers, manganese-reducers and denitrifiers showed abundance of all groups with a slight trend with the redox conditions. PLFA measurements did not provide much insight into the microbial populations of the plume, but confirmed some previous observations. Bioassays gave estimates of the rates of the various redox processes, but showed for some samples more simultaneous redox processes. More than 25 years of work has been put into the Grindsted Landfill leachate plume. References Bjerg, P.L., Rugge, K., Cortsen, J., Nielsen, P.H. & Christensen, T.H. (1999): Degradation of aromatic and chlorinated aliphatic hydrocarbons in the anaerobic part of the Grindsted Landfill leachate plume: In situ microcosm and laboratory batch

  8. Sulfate Reduction Remediation of a Metals Plume Through Organic Injection

    International Nuclear Information System (INIS)

    Phifer, M.A.

    2003-01-01

    Laboratory testing and a field-scale demonstration for the sulfate reduction remediation of an acidic/metals/sulfate groundwater plume at the Savannah River Site has been conducted. The laboratory testing consisted of the use of anaerobic microcosms to test the viability of three organic substrates to promote microbially mediated sulfate reduction. Based upon the laboratory testing, soybean oil and sodium lactate were selected for injection during the subsequent field-scale demonstration. The field-scale demonstration is currently ongoing. Approximately 825 gallons (3,123 L) of soybean oil and 225 gallons (852 L) of 60 percent sodium lactate have been injected into an existing well system within the plume. Since the injections, sulfate concentrations in the injection zone have significantly decreased, sulfate-reducing bacteria concentrations have significantly increased, the pH has increased, the Eh has decreased, and the concentrations of many metals have decreased. Microbially mediated sulfate reduction has been successfully promoted for the remediation of the acidic/metals/sulfate plume by the injection of soybean oil and sodium lactate within the plume

  9. Mathematical models for atmospheric pollutants. Appendix D. Available air quality models. Final report

    International Nuclear Information System (INIS)

    Drake, R.L.; McNaughton, D.J.; Huang, C.

    1979-08-01

    Models that are available for the analysis of airborne pollutants are summarized. In addition, recommendations are given concerning the use of particular models to aid in particular air quality decision making processes. The air quality models are characterized in terms of time and space scales, steady state or time dependent processes, reference frames, reaction mechanisms, treatment of turbulence and topography, and model uncertainty. Using these characteristics, the models are classified in the following manner: simple deterministic models, such as air pollution indices, simple area source models and rollback models; statistical models, such as averaging time models, time series analysis and multivariate analysis; local plume and puff models; box and multibox models; finite difference or grid models; particle models; physical models, such as wind tunnels and liquid flumes; regional models; and global models

  10. Reaction between laser ablation plume and ambient gas studied by laser-induced fluorescence imaging spectroscopy

    International Nuclear Information System (INIS)

    Sasaki, K; Watarai, H

    2007-01-01

    We visualized the density distributions of C 2 (plume), NO (ambient gas), and CN (reaction product) when a graphite target was ablated by irradiating YAG laser pulses at wavelengths of 1064 and 355 nm in ambient gas mixture of NO and He. It has been shown by the density distributions of C 2 and NO that the expansion of the plume removes the ambient gas and the plume and the ambient gas locate exclusively in both the cases at 1064 and 355 nm. A high CN density was observed at the interface between the plume and the ambient gas at 1064 nm, which is reasonable since chemical reactions between the plume and the ambient gas may occur only at their interface. On the other hand, in the case at 355 nm, we observed considerable CN inside the plume, indicating that the chemical reaction processes in the laser ablation at 355 nm is different from that expected from the density distributions of the plume and the ambient gas

  11. Global volcanic emissions: budgets, plume chemistry and impacts

    Science.gov (United States)

    Mather, T. A.

    2012-12-01

    Over the past few decades our understanding of global volcanic degassing budgets, plume chemistry and the impacts of volcanic emissions on our atmosphere and environment has been revolutionized. Global volcanic emissions budgets are needed if we are to make effective use of regional and global atmospheric models in order to understand the consequences of volcanic degassing on global environmental evolution. Traditionally volcanic SO2 budgets have been the best constrained but recent efforts have seen improvements in the quantification of the budgets of other environmentally important chemical species such as CO2, the halogens (including Br and I) and trace metals (including measurements relevant to trace metal atmospheric lifetimes and bioavailability). Recent measurements of reactive trace gas species in volcanic plumes have offered intriguing hints at the chemistry occurring in the hot environment at volcanic vents and during electrical discharges in ash-rich volcanic plumes. These reactive trace species have important consequences for gas plume chemistry and impacts, for example, in terms of the global fixed nitrogen budget, volcanically induced ozone destruction and particle fluxes to the atmosphere. Volcanically initiated atmospheric chemistry was likely to have been particularly important before biological (and latterly anthropogenic) processes started to dominate many geochemical cycles, with important consequences in terms of the evolution of the nitrogen cycle and the role of particles in modulating the Earth's climate. There are still many challenges and open questions to be addressed in this fascinating area of science.

  12. Bubbles generated from wind-steepened breaking waves: 1. Bubble plume bubbles

    NARCIS (Netherlands)

    Leifer, I.; Leeuw, G. de

    2006-01-01

    Measurements of bubble plumes from paddle-amplified, wind stress breaking waves were made in a large wind-wave channel during the LUMINY experiment in fresh (but not clean) water. Bubble plumes exhibited considerable variability with respect to dynamics, bubble size distribution, and physical

  13. The Role of Viscosity Contrast on the Plume Structure and Dynamics in High Rayleigh Number Convection

    Science.gov (United States)

    Kr, Sreenivas; Prakash, Vivek N.; Arakeri, Jaywant H.

    2010-11-01

    We study the plume structure in high Rayleigh number convection in the limit of large Prandtl numbers. This regime is relevant in Mantle convection, where the plume dynamics is not well understood due to complex rheology and chemical composition. We use analogue laboratory experiments to mimic mantle convection. Our focus in this paper is to understand the role of viscosity ratio, U, between the plume fluid and the ambient fluid on the structure and dynamics of the plumes. The PLIF technique has been used to visualize the structures of plumes rising from a planar source of compositional buoyancy at different regimes of U (1/300 to 2500). In the near-wall planform when U is one, a well-known dendritic line plume structure is observed. As U increases (U > 1; mantle hot spots), there is a morphological transition from line plumes to discrete spherical blobs, accompanied by an increase in the plume spacing and thickness. In vertical sections, as U increases (U > 1), the plume head shape changes from a mushroom-like structure to a "spherical-blob." When the U is decreased below one, (U<1; subduction regime), the formation of cellular patterns is favoured with sheet plumes. Both velocity and mixing efficiency are maximum when U is one, and decreases for extreme values of U. We quantify the morphological changes, dynamics and mixing variations of the plumes from experiments at different regimes.

  14. Influence of main forcing affecting the Tagus turbid plume under high river discharges using MODIS imagery.

    Science.gov (United States)

    Fernández-Nóvoa, D; Gómez-Gesteira, M; Mendes, R; deCastro, M; Vaz, N; Dias, J M

    2017-01-01

    The role of river discharge, wind and tide on the extension and variability of the Tagus River plume was analyzed from 2003 to 2015. This study was performed combining daily images obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor located onboard the Aqua and Terra satellites. Composites were generated by averaging pixels with the same forcing conditions. River discharge shows a strong relation with the extension of the Tagus plume. The plume grows with the increasing river discharge and express a two day lag caused by the long residence time of water within the estuary. The Tagus turbid plume was found to be smaller under northerly and easterly winds, than under southerly and westerly winds. It is suggested that upwelling favoring winds provoke the offshore movement of the plume material with a rapidly decrease in turbidity values whereas downwelling favoring winds retain plume material in the north coast close to the Tagus mouth. Eastern cross-shore (oceanward) winds spread the plume seaward and to the north following the coast geometry, whereas western cross-shore (landward) winds keep the plume material in both alongshore directions occupying a large part of the area enclosed by the bay. Low tides produce larger and more turbid plumes than high tides. In terms of fortnightly periodicity, the maximum plume extension corresponding to the highest turbidity is observed during and after spring tides. Minimum plume extension associated with the lowest turbidity occurs during and after neap tides.

  15. Influence of main forcing affecting the Tagus turbid plume under high river discharges using MODIS imagery.

    Directory of Open Access Journals (Sweden)

    D Fernández-Nóvoa

    Full Text Available The role of river discharge, wind and tide on the extension and variability of the Tagus River plume was analyzed from 2003 to 2015. This study was performed combining daily images obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS sensor located onboard the Aqua and Terra satellites. Composites were generated by averaging pixels with the same forcing conditions. River discharge shows a strong relation with the extension of the Tagus plume. The plume grows with the increasing river discharge and express a two day lag caused by the long residence time of water within the estuary. The Tagus turbid plume was found to be smaller under northerly and easterly winds, than under southerly and westerly winds. It is suggested that upwelling favoring winds provoke the offshore movement of the plume material with a rapidly decrease in turbidity values whereas downwelling favoring winds retain plume material in the north coast close to the Tagus mouth. Eastern cross-shore (oceanward winds spread the plume seaward and to the north following the coast geometry, whereas western cross-shore (landward winds keep the plume material in both alongshore directions occupying a large part of the area enclosed by the bay. Low tides produce larger and more turbid plumes than high tides. In terms of fortnightly periodicity, the maximum plume extension corresponding to the highest turbidity is observed during and after spring tides. Minimum plume extension associated with the lowest turbidity occurs during and after neap tides.

  16. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, P.; Nielsen, Peter Vilhelm

    The main objective of ventilation is to provide good air quality for the occupants. For this purpose the necessary ventilating air change rate must be determined. Within displacement ventilation the estimation is closely related to the air flow rate in the thermal plumes when an air quality based...

  17. Distribution of zooplankton populations within and adjacent to a thermal plume

    International Nuclear Information System (INIS)

    Evans, M.S.

    1981-01-01

    Zooplankton distributions in the 1-m stratum differed between ambient waters and the thermal plume of the Donald C. Cook Nuclear Power Plant. Zooplankton were most abundant in the warmest waters of the plume with the region of high densities extending over an approximate area of 0.2 to 0.3 km 2 . Water temperature was not a reliable indicator of alterations in zooplankton populations. Alterations were primarily due to upward vertical displacment of deep-living zooplankton. Large horizontal variability in zooplankton densities and use of conventional sampling procedures (vertically hauled nets, widely spaced stations) prevent traditionally designed monitoring programs from detecting such alterations. Zooplankton may experience indirect mortality losses in the plume if transfer of deep-living zooplankton to the surface layers makes them more visible to visual-feeding fish predators, and turbulences in the plume reduce zooplankters' ability to detect and avoid such predators. (auth)

  18. Showmaker-Levy 9 and plume-forming collisions on Earth

    Energy Technology Data Exchange (ETDEWEB)

    Boslough, M.B.E.; Crawford, D.A.

    1995-12-31

    Computational models for the July, 1994 collision of comet Shoemaker-Levy 9 with Jupiter have provided a framework for interpreting the observational data. Imaging, photometry, and spectroscopy data from ground-based, Hubble Space Telescope, and Galileo spacecraft instruments are consistent with phenomena that were dominated by the generation of incandescent fireballs that were ballistically ejected to high altitudes, where they formed plumes that subsequently collapsed over large areas of Jupiter`s atmosphere. Applications of similar computational models to collisions into Earth`s atmosphere show that a very similar sequence of events should take place for NEO impacts with energies as low as 3 megatons, recurring on 100 year timescales or less. This result suggests that the 1908 Tunguska event was a plume-forming atmospheric explosion, and that some of the phenomena associated with it might be related to the ejection and collapse of a high plume. Hazards associated with plume growth and collapse should be included in the evaluation of the impact threat to Earth, and opportunities should be sought for observational validation of atmospheric impact models by exploiting data already being collected from the natural flux of multi-kiloton to megaton sized objects that constantly enter Earth`s atmosphere on annual to decadal timescales.

  19. Modeling Macro- and Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes

    Science.gov (United States)

    Menon, Suresh

    1998-01-01

    Simulation of turbulent mixing and chemical processes in the near-field plume and plume-vortex regimes has been successfully carried out recently using a reduced gas phase kinetics mechanism which substantially decreased the computational cost. A detailed mechanism including gas phase HOx, NOx, and SOx chemistry between the aircraft exhaust and the ambient air in near-field aircraft plumes is compiled. A reduced mechanism capturing the major chemical pathways is developed. Predictions by the reduced mechanism are found to be in good agreement with those by the detailed mechanism. With the reduced chemistry, the computer CPU time is saved by a factor of more than 3.5 for the near-field plume modeling. Distributions of major chemical species are obtained and analyzed. The computed sensitivities of major species with respect to reaction step are deduced for identification of the dominant gas phase kinetic reaction pathways in the jet plume. Both the near field plume and the plume-vortex regimes were investigated using advanced mixing models. In the near field, a stand-alone mixing model was used to investigate the impact of turbulent mixing on the micro- and macro-scale mixing processes using a reduced reaction kinetics model. The plume-vortex regime was simulated using a large-eddy simulation model. Vortex plume behind Boeing 737 and 747 aircraft was simulated along with relevant kinetics. Many features of the computed flow field show reasonable agreement with data. The entrainment of the engine plumes into the wing tip vortices and also the partial detrainment of the plume were numerically captured. The impact of fluid mechanics on the chemical processes was also studied. Results show that there are significant differences between spatial and temporal simulations especially in the predicted SO3 concentrations. This has important implications for the prediction of sulfuric acid aerosols in the wake and may partly explain the discrepancy between past numerical studies

  20. SNIFFER: An aerial platform for the plume phase of a nuclear emergency

    Science.gov (United States)

    Castelluccio, D. M.; Cisbani, E.; Frullani, S.

    2012-04-01

    When a nuclear or radiological accident results in a release of a radioactive plume, AGS (Aerial Gamma Spectrometry) systems used in many countries, equipped with passive detectors, can help in giving quantitative assessment on the radiological situation (land surface contamination level) only when the air contamination due to the passage of the travelling plume has become negligible. To overcome this limitation, the Italian Institute of Health has developed and implemented a multi purpose air sampling system based on a fixed wing aircraft, for time-effective, large areas radiological surveillance (to face radiological emergency and to support homeland security). A fixed wing aircraft (Sky Arrow 650) with the front part of the fuselage properly adapted to house the detection equipment has been equipped with a compact air sampling line where the isokinetic sampling is dynamically maintained. Aerosol is collected on a Teflon® filter positioned along the line and hosted on a rotating 4-filters disk. A complex of detectors allows radionuclide identification in the collected aerosol samples. A correlated analysis of these two detectors data allows a quantitative measurement of air as well as ground surface concentration of gamma emitting radioisotopes. Environmental sensors and a GPS receiver support the characterization of the sampling conditions and the temporal and geolocation of the acquired data. Acquisition and control system based on compact electronics and real time software that operate the sampling line actuators, guarantee the dynamical isokinetic condition, and acquire the detectors and sensor data. The system is also equipped with other sampling lines to provide information on the concentration of other chemical pollutants. Operative flights have been carried out in the last years, and performances and results are presented.

  1. Bubbles generated from wind-steepened breaking waves: 2. Bubble plumes, bubbles, and wave characteristics

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G.de

    2006-01-01

    Measurements of breaking-wave-generated bubble plumes were made in fresh (but not clean) water in a large wind-wave tunnel. To preserve diversity, a classification scheme was developed on the basis of plume dimensions and "optical density," or the plume's ability to obscure the background. Optically

  2. Numerical modeling of plasma plume evolution against ambient background gas in laser blow off experiments

    International Nuclear Information System (INIS)

    Patel, Bhavesh G.; Das, Amita; Kaw, Predhiman; Singh, Rajesh; Kumar, Ajai

    2012-01-01

    Two dimensional numerical modelling based on simplified hydrodynamic evolution for an expanding plasma plume (created by laser blow off) against an ambient background gas has been carried out. A comparison with experimental observations shows that these simulations capture most features of the plasma plume expansion. The plume location and other gross features are reproduced as per the experimental observation in quantitative detail. The plume shape evolution and its dependence on the ambient background gas are in good qualitative agreement with the experiment. This suggests that a simplified hydrodynamic expansion model is adequate for the description of plasma plume expansion.

  3. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection

    Science.gov (United States)

    Álvarez-Romero, Jorge G.; Pressey, Robert L.; Ban, Natalie C.; Brodie, Jon

    2015-01-01

    Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our

  4. Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection.

    Directory of Open Access Journals (Sweden)

    Jorge G Álvarez-Romero

    Full Text Available Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both

  5. Dispersal of suspended sediments in the turbid and highly stratified Red River plume

    Science.gov (United States)

    van Maren, D. S.; Hoekstra, P.

    2005-03-01

    The Red River, annually transporting 100 million tons of sediment, flows into a shallow shelf sea where it rapidly deposits most of its sediment on a prograding delta front. Oceanographic cruises were carried out in February-March and July-August 2000 to determine the vertical structure of the Ba Lat river plume and sediment transport patterns on the delta front. The surface waters in the coastal zone were strongly stratified with a low density and high sediment concentration during the larger part of the wet season, caused by low mixing rates of river plumes with ambient water. The river plume is advected to the south by a well-developed coastal current which originates from the river plumes that enter the Gulf of Tonkin North of the Ba Lat and are deflected southward by the Coriolis force. Sediment predominantly leaves the surface plume by settling from suspension and less by mixing of fresh and marine water. A one-dimensional model for plume deposition valid for fair weather conditions indicates that most sediment is deposited within 10 km and southward of the river mouth. Of prime importance for this depositional pattern is the phase relation between river outflow and tidal currents, in combination with the southward surface flow; alongshore advection is very low during outflow of the turbid river plume. The agreement of modeled plume sedimentation patterns with long-term bathymetric changes strongly suggests that fair weather depositional processes determine delta front development. This may be related to the fact that reworking of sediment mainly occurs several months after the peak deposition period; in the meantime sediment compaction and consolidation have increased the shear strength of deposited sediments.

  6. Influences of source condition and dissolution on bubble plume in a stratified environment

    Science.gov (United States)

    Chu, Shigan; Prosperetti, Andrea

    2017-11-01

    A cross-sectionally averaged model is used to study a bubble plume rising in a stratified quiescent liquid. Scaling analyses for the peel height, at which the plume momentum vanishes, and the neutral height, at which its average density equals the ambient density, are presented. Contrary to a widespread practice in the literature, it is argued that the neutral height cannot be identified with the experimentally reported intrusion height. Recognizing this difference provides an explanation of the reason why the intrusion height is found so frequently to lie so much above predictions, and brings the theoretical results in line with observations. The mathematical model depends on three dimensionless parameters, some of which are related to the inlet conditions at the plume source. Their influence on the peel and neutral heights is illustrated by means of numerical results. Aside from the source parameters, we incorporate dissolution of bubbles and the corresponding density change of plume into the model. Contrary to what's documented in literature, density change of plume due to dissolution plays an important role in keeping the total buoyancy of plume, thus alleviating the rapid decrease of peel height because of dissolution.

  7. Aerosol composition of urban plumes passing over a rural monitoring site

    International Nuclear Information System (INIS)

    Ellestad, T.G.

    1980-01-01

    A field study conducted at a ground site 100 km north of St. Louis, Mo., to measure the aerosol composition and gaseous concentrations of urban plumes passing the site is discussed. Coarse and fine aerosol elemental concentrations, height scattering, meteorological data and concentrations of SO 2 , CO, O 3 , and NO-NO/sub x/ were measured and then analyzed together with data from associate investigators on fluorocarbon-11, total hydrocarbons, and size distributions. The results show that: (1) gaseous and elemental aerosol concentrations at the ground site 100 km from the St. Louis urban area were clearly influenced by the St. Louis urban plume, (2) the urban plumes of Chicago and Indianapolis, 350 km from the ground site, may have been detected, (3) sulfur compounds, presumably sulfates, accounted for 30-40% of the mass loading within the St. Louis urban plume, and resided almost entirely within the size range below 2.5 microns, (4) the most reliable urban-plume tracers in this study were fine Pb, fluorocarbon-11, total nonmethane hydrocarbons, and CO, and (5) over a period of several days, there may have been a regional buildup of fine S, light scattering, aerosol mass, O 3 , and NO/sub x/ and, to a lesser extent, CO and fluorocarbon-11

  8. Buoyant plumes from solute gradients generated by non-motile Escherichia coli

    International Nuclear Information System (INIS)

    Benoit, M R; Brown, R B; Todd, P; Klaus, D M; Nelson, E S

    2008-01-01

    The effect of hydrodynamic mixing in bacterial populations due to bacterial chemotaxis is a well-described phenomenon known as bioconvection. Here we report the observation of buoyant plumes that result in hydrodynamic mixing, but in contrast to bioconvection the plumes form in the absence of bacterial motility. We propose that the buoyant flow originates from solute gradients created by bacterial metabolism, similar to solute-induced buoyant flow around growing protein crystals. In our experiments, metabolically-active non-motile Escherichia coli were layered along the bottom of flat-bottomed containers. The E. coli consumed glucose in the medium creating a lighter fluid beneath a heavier fluid. The situation is an example of Rayleigh–Taylor instability, in which a lighter fluid pushes on a heavier one. We developed a numerical model to study the effect of E. coli nutrient consumption and by-product excretion on extracellular solute gradients. The model solutions showed reduced-density fluid along the bottom of the fluid domain leading to buoyant plumes, which were qualitatively similar to the experimental plumes. We also used scaling analyses to study the dependence of plume formation on container size and cell size, and to investigate the effect of reduced gravity, such as the microgravity conditions encountered during spaceflight

  9. Determining Aerosol Plume Height from Two GEO Imagers: Lessons from MISR and GOES

    Science.gov (United States)

    Wu, Dong L.

    2012-01-01

    Aerosol plume height is a key parameter to determine impacts of particulate matters generated from biomass burning, wind-blowing dust, and volcano eruption. Retrieving cloud top height from stereo imageries from two GOES (Geostationary Operational Environmental Satellites) have been demonstrated since 1970's and the principle should work for aerosol plumes if they are optically thick. The stereo technique has also been used by MISR (Multiangle Imaging SpectroRadiometer) since 2000 that has nine look angles along track to provide aerosol height measurements. Knowing the height of volcano aerosol layers is as important as tracking the ash plume flow for aviation safety. Lack of knowledge about ash plume height during the 2010 Eyja'rjallajokull eruption resulted in the largest air-traffic shutdown in Europe since World War II. We will discuss potential applications of Asian GEO satellites to make stereo measurements for dust and volcano plumes.

  10. Satellite infrared imagery for thermal plume contamination monitoring in coastal ecosystem of Cernavoda NPP

    Science.gov (United States)

    Zoran, M. A.; Zoran, Liviu Florin V.; Dida, Adrian I.

    2017-10-01

    Satellite remote sensing is an important tool for spatio-temporal analysis and surveillance of NPP environment, thermal heat waste of waters being a major concern in many coastal ecosystems involving nuclear power plants. As a test case the adopted methodology was applied for 700x2 MW Cernavoda nuclear power plant (NPP) located in the South-Eastern part of Romania, which discharges warm water affecting coastal ecology. The thermal plume signatures in the NPP hydrological system have been investigated based on TIR (Thermal Infrared) spectral bands of NOAA AVHRR, Landsat TM/ETM+/OLI, and MODIS Terra/Aqua time series satellite data during 1990-2016 period. If NOAA AVHRR data proved the general pattern and extension of the thermal plume signature in Danube river and Black Sea coastal areas, Landsat TM/ETM and MODIS data used for WST (Water Surface Temperature) change detection, mapping and monitoring provided enhanced information about the plume shape, dimension and direction of dispersion in these waters. Thermal discharge from two nuclear reactors cooling is dissipated as waste heat in Danube-Black -Sea Channel and Danube River. From time-series analysis of satellite data during period 1990-2016 was found that during the winter season thermal plume was localized to an area of a few km of NPP, and the mean temperature difference between the plume and non-plume areas was about 1.7 oC. During summer and fall, derived mean temperature difference between the plume and non-plume areas was of about 1.3°C and thermal plume area was extended up to 5- 10 km far along Danube Black Sea Channel.

  11. Issues concerning the determination of solubility products of sparingly soluble crystalline solids. Solubility of HfO{sub 2}(cr)

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Dhanpat [Rai Enviro-Chem, LLC, Yachats, OR (United States); Kitamura, Akira [Japan Atomic Energy Agency, Ibaraki (Japan); Rosso, Kevin M. [Pacific Northwest National Laboratory, Richland, WA (United States); Sasaki, Takayuki; Kobayashi, Taishi [Kyoto Univ. (Japan)

    2016-11-01

    Solubility studies were conducted with HfO{sub 2}(cr) solid as a function HCl and ionic strength ranging from 2.0 to 0.004 mol kg{sup -1}. These studies involved (1) using two different amounts of the solid phase, (2) acid washing the bulk solid phase, (3) preheating the solid phase to 1400 C, and (4) heating amorphous HfO{sub 2}(am) suspensions to 90 C to ascertain whether the HfO{sub 2}(am) converts to HfO{sub 2}(cr) and to determine the solubility from the oversaturation direction. Based on the results of these treatments it is concluded that the HfO{sub 2}(cr) contains a small fraction of less crystalline, but not amorphous, material [HfO{sub 2}(lcr)] and this, rather than the HfO{sub 2}(cr), is the solubility-controlling phase in the range of experimental variables investigated in this study. The solubility data are interpreted using both the Pitzer and SIT models and they provide log{sub 10} K{sup 0} values of -(59.75±0.35) and -(59.48±0.41), respectively, for the solubility product of HfO{sub 2}(lcr)[HfO{sub 2}(lcr) + 2H{sub 2}O ↔ Hf{sup 4+} + 4OH{sup -}]. The log{sub 10} of the solubility product of HfO{sub 2}(cr) is estimated to be < -63. The observation of a small fraction of less crystalline higher solubility material is consistent with the general picture that mineral surfaces are often structurally and/or compositionally imperfect leading to a higher solubility than the bulk crystalline solid. This study stresses the urgent need, during interpretation of solubility data, of taking precautions to make certain that the observed solubility behavior for sparingly-soluble solids is assigned to the proper solid phase.

  12. Monitoring the decontamination of a site polluted by DNAPLs

    Science.gov (United States)

    Audí-Miró, C.; Espinola, R.; Torrentó, C.; Otero, N.; Rossi, A.; Palau, J.; Soler, A.

    2012-04-01

    The aim of this study is to monitor the decontamination of a site polluted by DNAPLs coming from an automotive industry. The contamination was caused by the poor management of the waste generated by the industrial activity, which was discharged into a seepage pit. As a result, soil contamination was produced in the seepage pit area and a plume of DNAPLs-contaminated groundwater was generated. To recover the original environmental quality, a dual action was proposed: in the first place, the removal of the source of contamination and in the second one, the treatment of the DNAPLs plume. The elimination of the source of contamination consisted on a selective excavation of the seepage pit and an offsite management of the contaminated land. To restore the groundwater quality, a passive treatment system using a permeable reactive barrier (PRB) of zero valent iron (ZVI) was implemented. In order to determine the efficiency of the remediation actions, a chemical, isotopic and hydrogeological control of the main solvents detected in groundwater (perchloroethylene -PCE-, trichloroethene -TCE- and cis-dichloroethylene -cis-DCE-) has been established. Results show a decrease in PCE concentration that has been attributed to the removal of the source more than to a degradation process. However, the presence of PCE by-products, TCE and cis-DCE, might indicate a possible PCE biotic degradation. δ13CPCE values analyzed upstream and downstream of the barrier don't show isotopic changes associated to the PRB (values are around -20‰ in all the sampling points). TCE might have experienced a natural advanced degradation process according to the high concentration of cis-DCE found prior the installation of the PRB and the isotopic enrichment in δ13CTCE in some specific areas of the plume (-19.9‰ in the source and -16‰ before the barrier). Slight isotopic changes have been observed in the water flow in a far distance after the barrier (-15.4‰). δ13Ccis-DCE experienced an

  13. Particle Simulation of Pulsed Plasma Thruster Plumes

    National Research Council Canada - National Science Library

    Boyd, Ian

    2002-01-01

    .... Our modeling had made progress in al aspects of simulating these complex devices including Teflon ablation, plasma formation, electro-magnetic acceleration, plume expansion, and particulate transport...

  14. Three-dimensional simulation of gas and dust in Io's Pele plume

    Science.gov (United States)

    McDoniel, William J.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.

    2015-09-01

    Io's giant Pele plume rises high above the moon's surface and produces a complex deposition pattern. We use the direct simulation Monte Carlo (DSMC) method to model the flow of SO2 gas and silicate ash from the surface of the lava lake, into the umbrella-shaped canopy of the plume, and eventually onto the surface where the flow leaves black "butterfly wings" surrounded by a large red ring. We show how the geometry of the lava lake, from which the gas is emitted, is responsible for significant asymmetry in the plume and for the shape of the red deposition ring by way of complicated gas-dynamic interactions between parts of the gas flow arising from different areas in the lava lake. We develop a model for gas flow in the immediate vicinity of the lava lake and use it to show that the behavior of ash particles of less than about 2 μm in diameter in the plume is insensitive to the details of how they are introduced into the flow because they are coupled to the gas at low altitudes. We simulate dust particles in the plume to show how particle size determines the distance from the lava lake at which particles deposit on the surface, and we use this dependence to find a size distribution of black dust particles in the plume that provides the best explanation for the observed black fans to the east and west of the lava lake. This best-fit particle size distribution suggests that there may be two distinct mechanisms of black dust creation at Pele, and when two log-normal distributions are fit to our results we obtain a mean particle diameter of 88 nm. We also propose a mechanism by which the condensible plume gas might overlay black dust in areas where black coloration is not observed and compare this to the observed overlaying of Pillanian dust by Pele's red ring.

  15. Moment analysis description of wetting and redistribution plumes in wettable and water-repellent soils

    Science.gov (United States)

    Xiong, Yunwu; Furman, Alex; Wallach, Rony

    2012-02-01

    SummaryWater repellency has a significant impact on water flow patterns in the soil profile. Transient 2D flow in wettable and natural water-repellent soils was monitored in a transparent flow chamber. The substantial differences in plume shape and spatial water content distribution during the wetting and subsequent redistribution stages were related to the variation of contact angle while in contact with water. The observed plumes shape, internal water content distribution in general and the saturation overshoot behind the wetting front in particular in the repellent soils were associated with unstable flow. Moment analysis was applied to characterize the measured plumes during the wetting and subsequent redistribution. The center of mass and spatial variances determined for the measured evolving plumes were fitted by a model that accounts for capillary and gravitational driving forces in a medium of temporally varying wettability. Ellipses defined around the stable and unstable plumes' centers of mass and whose semi-axes represented a particular number of spatial variances were used to characterize plume shape and internal moisture distribution. A single probability curve was able to characterize the corresponding fractions of the total added water in the different ellipses for all measured plumes, which testify the competence and advantage of the moment analysis method.

  16. Total peroxy nitrates and ozone production : analysis of forest fire plumes during BORTAS campaign

    Science.gov (United States)

    Busilacchio, Marcella; Di Carlo, Piero; Aruffo, Eleonora; Biancofiore, Fabio; Giammaria, Franco; Bauguitte, Stephane; Lee, James; Moller, Sarah; Lewis, Ally; Parrington, Mark; Palmer, Paul; Dari Salisburgo, Cesare

    2014-05-01

    The goal of this work is to investigate the connection between PNS and ozone within plumes emitted from boreal forest fires and the possible perturbation to oxidant chemistry in the troposphere. During the Aircraft campaign in Canada called BORTAS (summer 2011 ) were carried out several profiles from ground up to 10 km with the BAe-146 aircraft to observe the atmospheric composition inside and outside fire plumes. The BORTAS flights have been selected based on the preliminary studies of 'Plume identification', selecting those effected by Boreal forest fire emissions (CO > 200 ppbv). The FLAMBE fire counts were used concertedly with back trajectory calculations generated by the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to locate the sources of Boreal biomass burning.Profiles measured on board the BAe-146 aircraft are used to calculate the productions of PNs and O3 within the biomass burning plume. By selecting the flights that intercept the biomass burning plume, we evaluate the ratio between the ozone production and the PNs production within the plume. Analyzing this ratio it is possible to determine whether O3 production or PNs production is the dominant process in the biomass burning boreal plume detected during BORTAS campaign.

  17. Insights into a historic severe haze event in Shanghai: synoptic situation, boundary layer and pollutants

    Directory of Open Access Journals (Sweden)

    C. Leng

    2016-07-01

    Full Text Available A historic haze event, characterized by lengthy, large-scale and severe pollution, occurred in the Yangtze River Delta (YRD of China from 1 to 10 December 2013. This haze event significantly influenced air quality throughout the region, especially in urban areas. Aerosol physical, chemical and optical properties were measured in Shanghai. Sometimes the 1 h average particle concentration (e.g., PM2.5 exceeded 600 µg m−3. Inorganic water-soluble ions in particles, trace gases and aerosol optical coefficients had a similar tendency to increase evidently from clear to hazy episodes. A combination of various factors contributed to the formation and evolution of the haze event, among which meteorological conditions, local anthropogenic emissions and pollutants are the major factors. High pressure system, calm surface wind and subsidence airflow were responsible for the decrease of planetary boundary layer (PBL and the accumulation of pollutants. Atmospheric visibility correlated strongly with relative humidity (RH, particle number in size of 600–1400 nm other than particulate water-soluble species and particle mass (PM2.5. The particle hygroscopicity plays an important role in atmospheric visibility reduction. The results are somewhat helpful to forecast and eliminate regional atmospheric pollution in China.

  18. Characteristics of aerosol particles and trace gases in ship exhaust plumes

    Science.gov (United States)

    Drewnick, F.; Diesch, J.; Borrmann, S.

    2011-12-01

    -sulfur fuel, the chemical submicron aerosol fraction is mainly composed of hydrocarbon-like organic aerosol (HOA) species. These include PAHs that are adsorbed onto the high number of ultrafine particles. Nevertheless, the chemical composition, typical particle sizes as well as emitted gaseous components vary substantially dependent on the engine or ship type, engine operation condition and fuel mixture. This results in cargo vessels compared to tankers, passenger ships and river boats being the largest polluters influencing the Elbe shipping lane areas by high amounts of NOx, SO2, CO2, PAH, BC and ultrafine particulate matter. The tropospheric ozone chemistry in this area is also substantially affected particularly due to the increasing number of Elbe-passing ships. As onshore regions can be influenced by aged shipping plumes, trajectory pathways and transportation times were examined. As a consequence of the plumes' aging, variations of the organic fraction of the mass spectral fingerprints were found. Eyring, V. et al. (2010), Atmospheric Environment, 44, 4735-4771.

  19. Warning system based on theoretical-experimental study of dispersion of soluble pollutants in rivers Sistema de alerta com base em estudo teórico-experimental de dispersão de poluentes solúveis em rios

    Directory of Open Access Journals (Sweden)

    Celso B. de M. Ribeiro

    2011-10-01

    Full Text Available Information about capacity of transport and dispersion of soluble pollutants in natural streams are important in the management of water resources, especially in planning preventive measures to minimize the problems caused by accidental or intentional waste, in public health and economic activities that depend on the use of water. Considering this importance, this study aimed to develop a warning system for rivers, based on experimental techniques using tracers and analytical equations of one-dimensional transport of soluble pollutants conservative, to subsidizing the decision-making in the management of water resources. The system was development in JAVA programming language and MySQL database can predict the travel time of pollutants clouds from a point of eviction and graphically displays the temporal distribution of concentrations of passage clouds, in a particular location, downstream from the point of its launch.Informações sobre a capacidade de transporte e dispersão de poluentes solúveis em cursos de água naturais são importantes no gerenciamento dos recursos hídricos, principalmente no planejamento preventivo de medidas que visem a minimizar problemas à saúde pública e às atividades econômicas que dependem do uso da água, ocasionados por despejos acidentais ou intencionais. Considerando tal importância, este trabalho teve como objetivo desenvolver um sistema de alerta para rios, com base em resultados experimentais, utilizando técnicas de traçadores e equações analíticas de transporte unidimensional de poluentes solúveis conservativos, visando a subsidiar a tomada de decisão no gerenciamento dos recursos hídricos. O sistema desenvolvido em linguagem de programação JAVA e banco de dados MySQL permite prever o tempo de percurso da nuvem de poluentes a partir de um ponto de despejo de um poluente e apresenta, graficamente, a distribuição temporal de concentrações da passagem da nuvem, em um determinado local,

  20. Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo

    2014-01-01

    We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n plu , which is estimated from the current and the drift velocity, and the gas flow velocity v gas is examined. It is found that the dependence of the density on the gas flow velocity has relations of n plu ∝ log(v gas ). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity

  1. Satellite and Ground Based Monitoring of Aerosol Plumes

    International Nuclear Information System (INIS)

    Doyle, Martin; Dorling, Stephen

    2002-01-01

    Plumes of atmospheric aerosol have been studied using a range of satellite and ground-based techniques. The Sea-viewing WideField-of-view Sensor (SeaWiFS) has been used to observe plumes of sulphate aerosol and Saharan dust around the coast of the United Kingdom. Aerosol Optical Thickness (AOT) was retrieved from SeaWiFS for two events; a plume of Saharan dust transported over the United Kingdom from Western Africa and a period of elevated sulphate experienced over the Easternregion of the UK. Patterns of AOT are discussed and related to the synoptic and mesoscale weather conditions. Further observation of the sulphate aerosol event was undertaken using the Advanced Very High Resolution Radiometer instrument(AVHRR). Atmospheric back trajectories and weather conditions were studied in order to identify the meteorological conditions which led to this event. Co-located ground-based measurements of PM 10 and PM 2.5 were obtained for 4sites within the UK and PM 2.5/10 ratios were calculated in order to identify any unusually high or low ratios(indicating the dominant size fraction within the plume)during either of these events. Calculated percentiles ofPM 2.5/10 ratios during the 2 events examined show that these events were notable within the record, but were in noway unique or unusual in the context of a 3 yr monitoring record. Visibility measurements for both episodes have been examined and show that visibility degradation occurred during both the sulphate aerosol and Saharan dust episodes

  2. Gas solubilities widespread applications

    CERN Document Server

    Gerrard, William

    1980-01-01

    Gas Solubilities: Widespread Applications discusses several topics concerning the various applications of gas solubilities. The first chapter of the book reviews Henr's law, while the second chapter covers the effect of temperature on gas solubility. The third chapter discusses the various gases used by Horiuti, and the following chapters evaluate the data on sulfur dioxide, chlorine data, and solubility data for hydrogen sulfide. Chapter 7 concerns itself with solubility of radon, thoron, and actinon. Chapter 8 tackles the solubilities of diborane and the gaseous hydrides of groups IV, V, and

  3. Three-dimensional laser-induced fluorescence measurements of turbulent chemical plumes

    Science.gov (United States)

    True, Aaron; Crimaldi, John

    2017-11-01

    In order to find prey, mates, and suitable habitat, many organisms must navigate through complex chemical plume structures in turbulent flow environments. In this context, we investigate the spatial and temporal structure of chemical plumes released isokinetically into fractal-grid-generated turbulence in an open channel flow. We first utilized particle image velocimetry (PIV) to characterize flow conditions (mean free stream velocities, turbulence intensities, turbulent kinetic energy dissipation rates, Taylor Reynolds numbers). We then implemented a newly developed high-resolution, high-speed, volumetric scanning laser-induced fluorescence (LIF) system for near time-resolved measurements of three-dimensional chemical plume structures. We investigated cases with and without a cylinder wake, and compare statistical (mean, variance, intermittency, probability density functions) and spectral (power spectrum of concentration fluctuations) characteristics of the chemical plume structure. Stretching and folding of complex three-dimensional filament structures during chaotic turbulent mixing is greatly enhanced in the cylinder wake case. In future experiments, we will implement simultaneous PIV and LIF, enabling computation of the covariance of the velocity and chemical concentration fluctuations and thus estimation of turbulent eddy diffusivities. NSF PHY 1555862.

  4. Plumes do not Exist: Plate Circulation is Confined to Upper Mantle

    Science.gov (United States)

    Hamilton, W. B.

    2002-12-01

    Plumes from deep mantle are widely conjectured to define an absolute reference frame, inaugurate rifting, drive plates, and profoundly modify oceans and continents. Mantle properties and composition are assumed to be whatever enables plumes. Nevertheless, purported critical evidence for plume speculation is false, and all data are better interpreted without plumes. Plume fantasies are made ever more complex and ad hoc to evade contradictory data, and have no predictive value because plumes do not exist. All plume conjecture derives from Hawaii and the guess that the Emperor-Hawaii inflection records a 60-degree change in Pacific plate direction at 45 Ma. Paleomagnetic latitudes and smooth Pacific spreading patterns disprove any such change. Rationales for other fixed plumes collapse when tested, and hypotheses of jumping, splitting, and gyrating plumes are specious. Thermal and physical properties of Hawaiian lithosphere falsify plume predictions. Purported tomographic support elsewhere represents artifacts and misleading presentations. Asthenosphere is everywhere near solidus temperature, so melt needs a tensional setting for egress but not local heat. Gradational and inconsistent contrasts between MORB and OIB are as required by depth-varying melt generation and behavior in contrasted settings and do not indicate systematically unlike sources. MORB melts rise, with minimal reaction, through hot asthenosphere, whereas OIB melts react with cool lithosphere, and lose mass, by crystallizing refractories and retaining and assimilating fusibles. The unfractionated lower mantle of plume conjecture is contrary to cosmologic and thermodynamic data, for mantle below 660 km is more refractory than that above. Subduction, due to density inversion by top-down cooling that forms oceanic lithosphere, drives plate tectonics and upper-mantle circulation. It organizes plate motions and lithosphere stress, which controls plate boundaries and volcanic chains. Hinge rollback is the

  5. Multi-spacecraft observations of small-scale fluctuations in density and fields in plasmaspheric plumes

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2012-03-01

    Full Text Available In this event study, small-scale fluctuations in plasmaspheric plumes with time scales of ~10 s to minutes in the spacecraft frame are examined. In one event, plasmaspheric plumes are observed by Cluster, while IMAGE measured density enhancement at a similar location. Fluctuations in density exist in plumes as detected by Cluster and are accompanied by fluctuations in magnetic fields and electric fields. Magnetic fluctuations are transverse and along the direction of the plumes. The E/B ratio is smaller than the Alfvén velocity. Another similar event is briefly presented. We then consider physical properties of the fluctuations. Alfvén mode modulated by the feedback instability is one possibility, although non-local generation is likely. It is hard to show that the fluctuations represent a fast mode. Interchange motion is possible due to the consistency between measurements and expectations. The energy source could be a pressure or density gradient in plasmaspheric plumes. When more events are accumulated so that statistical analysis becomes feasible, this type of study will be useful to understand the time evolution of plumes.

  6. Tropical biomass burning smoke plume size, shape, reflectance, and age based on 2001–2009 MISR imagery of Borneo

    Directory of Open Access Journals (Sweden)

    C. S. Zender

    2012-04-01

    Full Text Available Land clearing for crops, plantations and grazing results in anthropogenic burning of tropical forests and peatlands in Indonesia, where images of fire-generated aerosol plumes have been captured by the Multi-angle Imaging SpectroRadiometer (MISR since 2001. Here we analyze the size, shape, optical properties, and age of distinct fire-generated plumes in Borneo from 2001–2009. The local MISR overpass at 10:30 a.m. misses the afternoon peak of Borneo fire emissions, and may preferentially sample longer plumes from persistent fires burning overnight. Typically the smoke flows with the prevailing southeasterly surface winds at 3–4 m s−1, and forms ovoid plumes whose mean length, height, and cross-plume width are 41 km, 708 m, and 27% of the plume length, respectively. 50% of these plumes have length between 24 and 50 km, height between 523 and 993 m and width between 18% and 30% of plume length. Length and cross-plume width are lognormally distributed, while height follows a normal distribution. Borneo smoke plume heights are similar to previously reported plume heights, yet Borneo plumes are on average nearly three times longer than previously studied plumes. This could be due to sampling or to more persistent fires and greater fuel loads in peatlands than in other tropical forests. Plume area (median 169 km2, with 25th and 75th percentiles at 99 km2 and 304 km2, respectively varies exponentially with length, though for most plumes a linear relation provides a good approximation. The MISR-estimated plume optical properties involve greater uncertainties than the geometric properties, and show patterns consistent with smoke aging. Optical depth increases by 15–25% in the down-plume direction, consistent with hygroscopic growth and nucleation overwhelming the effects of particle dispersion. Both particle single-scattering albedo and top-of-atmosphere reflectance peak about halfway down-plume, at

  7. Growth of plume ''resident'' fishes in Lake Michigan

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Smith, D.W.

    1974-01-01

    Brown trout, rainbow trout, and chinook salmon were collected from the Point Beach thermal discharge area, tagged with commercial dart tags and temperature-sensitive tags, and released back into the discharge area. RNA and DNA analyses were performed on epaxial muscle samples taken from each tagged fish recaptured in the plume area and from control fish. A table is presented to show mean weights, condition factors, and RNA-DNA ratios for each group of fish. Results indicated that the fish did not experience any severe growth abnormalities as a result of their residence in the thermal plume area

  8. INVESTIGATION OF THE FATE OF MERCURY IN A COAL COMBUSTION PLUME USING A STATIC PLUME DILUTION CHAMBER

    Energy Technology Data Exchange (ETDEWEB)

    Dennis L. Laudal

    2001-11-01

    The overall goal of the project was to further develop and then verify SPDC's ability to determine the physical and chemical transformations of mercury in combustion stack plumes. Specific objectives of the project were to perform controlled tests at the pilot scale using dynamic spiking of known mercury compounds (i.e., Hg{sup 0} and HgCl{sub 2}) to prove the ability of the SPDC to determine the following: whether mercury condenses onto particulate matter in a cooling plume; whether there is reduction of Hg{sup 2+} to Hg{sup 0} occurring in hygroscopic aerosols; whether condensed Hg{sup 2+} on particles is photochemically reduced to Hg{sup 0}; and whether or not the Solid Ontario Hydro mercury speciation method (SOH) provides the same results as the Ontario Hydro (OH) mercury speciation method.

  9. Constraining Diameters of Ash Particles in Io's Pele Plume by DSMC Simulation

    Science.gov (United States)

    McDoniel, William; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

    2013-10-01

    The black “butterfly wings” seen at Pele are produced by silicate ash which is to some extent entrained in the gas flow from very low altitudes. These particles are key to understanding the volcanism at Pele. However, the Pele plume is not nearly as dusty as Prometheus, and these are not the only particles in the plume, as the SO2 in the plume will also condense as it cools. It is therefore difficult to estimate a size distribution for the ash particles by observation, and the drag on ash particles from the plume flow is significant enough that ballistic models are also of limited use. Using Direct Simulation Monte Carlo, we can simulate a gas plume at Pele which demonstrates very good agreement with observations. By extending this model down to nearly the surface of the lava lake, ash particles can be included in the simulation by assuming that they are initially entrained in the very dense (for Io) gas immediately above the magma. Particles are seen to fall to the ground to the east and west of the vent, agreeing with the orientation of the “butterfly wings”, and particles with larger diameters fall to the ground closer to the lava lake. We present a model for mapping simulated deposition density to the coloration of the surface and we use it to estimate the size distribution of ash particles in the plume.

  10. Effects of a Simple Convective Organization Scheme in a Two-Plume GCM

    Science.gov (United States)

    Chen, Baohua; Mapes, Brian E.

    2018-03-01

    A set of experiments is described with the Community Atmosphere Model (CAM5) using a two-plume convection scheme. To represent the differences of organized convection from General Circulation Model (GCM) assumptions of isolated plumes in uniform environments, a dimensionless prognostic "organization" tracer Ω is invoked to lend the second plume a buoyancy advantage relative to the first, as described in Mapes and Neale (2016). When low-entrainment plumes are unconditionally available (Ω = 1 everywhere), deep convection occurs too easily, with consequences including premature (upstream) rainfall in inflows to the deep tropics, excessive convective versus large-scale rainfall, poor relationships to the vapor field, stable bias in the mean state, weak and poor tropical variability, and midday peak in diurnal rainfall over land. Some of these are shown to also be characteristic of CAM4 with its separated deep and shallow convection schemes. When low-entrainment plumes are forbidden by setting Ω = 0 everywhere, some opposite problems can be discerned. In between those extreme cases, an interactive Ω driven by the evaporation of precipitation acts as a local positive feedback loop, concentrating deep convection: In areas of little recent rain, only highly entraining plumes can occur, unfavorable for rain production. This tunable mechanism steadily increases precipitation variance in both space and time, as illustrated here with maps, time-longitude series, and spectra, while avoiding some mean state biases as illustrated with process-oriented diagnostics such as conserved variable profiles and vapor-binned precipitation curves.

  11. The contaminant legacy from historic coastal landfills and their potential as sources of diffuse pollution.

    Science.gov (United States)

    O'Shea, Francis T; Cundy, Andrew B; Spencer, Kate L

    2018-03-01

    Prior to modern environmental regulation landfills in low-lying coastal environments were frequently constructed without leachate control, relying on natural attenuation within inter-tidal sediments to dilute and disperse contaminants reducing environmental impact. With sea level rise and coastal erosion these sites may now pose a pollution risk, yet have received little investigation. This work examines the extent of metal contamination in saltmarsh sediments surrounding a historic landfill in the UK. Patterns of sediment metal data suggest typical anthropogenic pollution chronologies for saltmarsh sediments in industrialised nations. However, many metals were also enriched at depth in close proximity to the landfill boundary and are indicative of a historical leachate plume. Though this total metal load is low, e.g., c. 1200 and 1650kg Pb and Zn respectively, with >1000 historic landfills on flood risk or eroding coastlines in the UK this could represent a significant, yet under-investigated, source of diffuse pollution. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Three-Dimensional Numerical Analysis of LOX/Kerosene Engine Exhaust Plume Flow Field Characteristics

    Directory of Open Access Journals (Sweden)

    Hong-hua Cai

    2017-01-01

    Full Text Available Aiming at calculating and studying the flow field characteristics of engine exhaust plume and comparative analyzing the effects of different chemical reaction mechanisms on the engine exhaust plume flow field characteristics, a method considering fully the combustion state influence is put forward, which is applied to exhaust plume flow field calculation of multinozzle engine. On this basis, a three-dimensional numerical analysis of the effects of different chemical reaction mechanisms on LOX/kerosene engine exhaust plume flow field characteristics was carried out. It is found that multistep chemical reaction can accurately describe the combustion process in the LOX/kerosene engine, the average chamber pressure from the calculation is 4.63% greater than that of the test, and the average chamber temperature from the calculation is 3.34% greater than that from the thermodynamic calculation. The exhaust plumes of single nozzle and double nozzle calculated using the global chemical reaction are longer than those using the multistep chemical reaction; the highest temperature and the highest velocity on the plume axis calculated using the former are greater than that using the latter. The important influence of chemical reaction mechanism must be considered in the study of the fixing structure of double nozzle engine on the rocket body.

  13. The importance of vertical resolution in the free troposphere for modeling intercontinental plumes

    Science.gov (United States)

    Zhuang, Jiawei; Jacob, Daniel J.; Eastham, Sebastian D.

    2018-05-01

    Chemical plumes in the free troposphere can preserve their identity for more than a week as they are transported on intercontinental scales. Current global models cannot reproduce this transport. The plumes dilute far too rapidly due to numerical diffusion in sheared flow. We show how model accuracy can be limited by either horizontal resolution (Δx) or vertical resolution (Δz). Balancing horizontal and vertical numerical diffusion, and weighing computational cost, implies an optimal grid resolution ratio (Δx / Δz)opt ˜ 1000 for simulating the plumes. This is considerably higher than current global models (Δx / Δz ˜ 20) and explains the rapid plume dilution in the models as caused by insufficient vertical resolution. Plume simulations with the Geophysical Fluid Dynamics Laboratory Finite-Volume Cubed-Sphere Dynamical Core (GFDL-FV3) over a range of horizontal and vertical grid resolutions confirm this limiting behavior. Our highest-resolution simulation (Δx ≈ 25 km, Δz ≈ 80 m) preserves the maximum mixing ratio in the plume to within 35 % after 8 days in strongly sheared flow, a drastic improvement over current models. Adding free tropospheric vertical levels in global models is computationally inexpensive and would also improve the simulation of water vapor.

  14. Infrared signature modelling of a rocket jet plume - comparison with flight measurements

    International Nuclear Information System (INIS)

    Rialland, V; Perez, P; Roblin, A; Guy, A; Gueyffier, D; Smithson, T

    2016-01-01

    The infrared signature modelling of rocket plumes is a challenging problem involving rocket geometry, propellant composition, combustion modelling, trajectory calculations, fluid mechanics, atmosphere modelling, calculation of gas and particles radiative properties and of radiative transfer through the atmosphere. This paper presents ONERA simulation tools chained together to achieve infrared signature prediction, and the comparison of the estimated and measured signatures of an in-flight rocket plume. We consider the case of a solid rocket motor with aluminized propellant, the Black Brant sounding rocket. The calculation case reproduces the conditions of an experimental rocket launch, performed at White Sands in 1997, for which we obtained high quality infrared signature data sets from DRDC Valcartier. The jet plume is calculated using an in-house CFD software called CEDRE. The plume infrared signature is then computed on the spectral interval 1900-5000 cm -1 with a step of 5 cm -1 . The models and their hypotheses are presented and discussed. Then the resulting plume properties, radiance and spectra are detailed. Finally, the estimated infrared signature is compared with the spectral imaging measurements. The discrepancies are analyzed and discussed. (paper)

  15. The distribution and stabilisation of dissolved Fe in deep-sea hydrothermal plumes

    Science.gov (United States)

    Bennett, Sarah A.; Achterberg, Eric P.; Connelly, Douglas P.; Statham, Peter J.; Fones, Gary R.; German, Christopher R.

    2008-06-01

    We have conducted a study of hydrothermal plumes overlying the Mid-Atlantic Ridge near 5° S to investigate whether there is a significant export flux of dissolved Fe from hydrothermal venting to the oceans. Our study combined measurements of plume-height Fe concentrations from a series of 6 CTD stations together with studies of dissolved Fe speciation in a subset of those samples. At 2.5 km down plume from the nearest known vent site dissolved Fe concentrations were ˜ 20 nM. This is much higher than would be predicted from a combination of plume dilution and dissolved Fe(II) oxidation rates, but consistent with stabilisation due to the presence of organic Fe complexes and Fe colloids. Using Competitive Ligand Exchange-Cathodic Stripping Voltammetry (CLE-CSV), stabilised dissolved Fe complexes were detected within the dissolved Fe fraction on the edges of one non-buoyant hydrothermal plume with observed ligand concentrations high enough to account for stabilisation of ˜ 4% of the total Fe emitted from the 5° S vent sites. If these results were representative of all hydrothermal systems, submarine venting could provide 12-22% of the global deep-ocean dissolved Fe budget.

  16. Levy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    International Nuclear Information System (INIS)

    Pasternak, Zohar; Grasso, Frank W; Bartumeus, Frederic

    2009-01-01

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Levy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Levy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Levy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accommodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for food

  17. Hydrocarbon Plume Dynamics in the Worldś Most Spectacular Hydrocarbon Seeps, Santa Barbara Channel, California

    Science.gov (United States)

    Mau, S.; Reed, J.; Clark, J.; Valentine, D.

    2006-12-01

    Large quantities of natural gas are emitted from the seafloor into the coastal ocean near Coal Oil Point, Santa Barbara Channel (SBC), California. Methane, ethane, and propane were quantified in the surface water at 79 stations in a 270 km2 area in order to map the surficial hydrocarbon plume and to quantify air-sea exchange of these gases. A time series was initiated for 14 stations to identify the variability of the mapped plume, and biologically-mediated oxidation rates of methane were measured to quantify the loss of methane in surface water. The hydrocarbon plume was found to comprise ~70 km2 and extended beyond study area. The plume width narrowed from 3 km near the source to 0.7 km further from the source, and then expanded to 6.7 km at the edge of the study area. This pattern matches the cyclonic gyre which is the normal current flow in this part of the Santa Barbara Channel - pushing water to the shore near the seep field and then broadening the plume while the water turns offshore further from the source. Concentrations of gaseous hydrocarbons decrease as the plume migrates. Time series sampling shows similar plume width and hydrocarbon concentrations when normal current conditions prevail. In contrast, smaller plume width and low hydrocarbon concentrations were observed when an additional anticyclonic eddy reversed the normal current flow, and a much broader plume with higher hydrocarbon concentrations was observed during a time of diminished speed within the current gyre. These results demonstrate that surface currents control hydrocarbon plume dynamics in the SBC, though hydrocarbon flux to the atmosphere is likely less dependent on currents. Estimates of air- sea hydrocarbon flux and biological oxidation rates will also be presented.

  18. Levy-taxis: a novel search strategy for finding odor plumes in turbulent flow-dominated environments

    Energy Technology Data Exchange (ETDEWEB)

    Pasternak, Zohar; Grasso, Frank W [BioMimetic and Cognitive Robotics Laboratory, Department of Psychology, Brooklyn College, The City University of New York, 2900 Bedford Avenue, Brooklyn 11210, NY (United States); Bartumeus, Frederic [Department of Ecology and Evolutionary Biology and Princeton Environmental Institute, 106 Guyot Hall, Princeton University, Princeton 08544, NJ (United States)], E-mail: zpast@yahoo.com

    2009-10-30

    Locating chemical plumes in aquatic or terrestrial environments is important for many economic, conservation, security and health related human activities. The localization process is composed mainly of two phases: finding the chemical plume and then tracking it to its source. Plume tracking has been the subject of considerable study whereas plume finding has received little attention. We address here the latter issue, where the searching agent must find the plume in a region often many times larger than the plume and devoid of the relevant chemical cues. The probability of detecting the plume not only depends on the movements of the searching agent but also on the fluid mechanical regime, shaping plume intermittency in space and time; this is a basic, general problem when exploring for ephemeral resources (e.g. moving and/or concealing targets). Here we present a bio-inspired search strategy named Levy-taxis that, under certain conditions, located odor plumes significantly faster and with a better success rate than other search strategies such as Levy walks (LW), correlated random walks (CRW) and systematic zig-zag. These results are based on computer simulations which contain, for the first time ever, digitalized real-world water flow and chemical plume instead of their theoretical model approximations. Combining elements of LW and CRW, Levy-taxis is particularly efficient for searching in flow-dominated environments: it adaptively controls the stochastic search pattern using environmental information (i.e. flow) that is available throughout the course of the search and shows correlation with the source providing the cues. This strategy finds natural application in real-world search missions, both by humans and autonomous robots, since it accommodates the stochastic nature of chemical mixing in turbulent flows. In addition, it may prove useful in the field of behavioral ecology, explaining and predicting the movement patterns of various animals searching for food

  19. Capturing volcanic plumes in 3D with UAV-based photogrammetry at Yasur Volcano - Vanuatu

    Science.gov (United States)

    Gomez, C.; Kennedy, B.

    2018-01-01

    As a precise volume of volcanic ash-plume is essential to understand the dynamic of gas emission, exchanges and the eruptive dynamics, we have measured in 3D using photogrammetry a small-size volcanic plume at the summit of Yasur Volcano, Vanuatu. The objective was to collect the altitude and planform shape of the plume as well as the vertical variations of the shape and size. To reach this objective, the authors have used the Structure from Motion photogrammetric method applied to a series of photographs captured in a very short period of time around and above the plume. A total of 146 photographs at 3000 × 4000 pixel were collected as well as the geolocation, the pitch, tilt and orientation of the cameras. The results revealed a "mushroom"-like shape of the plume with a narrow ascending column topped by a turbulent mixing zone. The volume of the plume was calculated to be 13,430 m3 ± 512 m3 (with the error being the cube of the linear error from the Ground Control Points) for a maximum height above the terrain of 63 m. The included error was also kept high because of the irregular distribution of the Ground Control Points that could not be collected in dangerous areas due to the ongoing eruption. Based on this research, it is therefore worth investigating the usage of multiple cameras to capture plumes in 3D over time and the method is also a good complement to the recent development of photogrammetry from space, which can tackle larger-scale eruption plumes.

  20. Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.; Deng, Y.; Nostrand, J.D. Van; He, Z.; Voordeckers, J.; Zhou, A.; Lee, Y.-J.; Mason, O.U.; Dubinsky, E.; Chavarria, K.; Tom, L.; Fortney, J.; Lamendella, R.; Jansson, J.K.; D?haeseleer, P.; Hazen, T.C.; Zhou, J.

    2011-06-15

    The Deepwater Horizon oil spill in the Gulf of Mexico is the deepest and largest offshore spill in U.S. history and its impacts on marine ecosystems are largely unknown. Here, we showed that the microbial community functional composition and structure were dramatically altered in a deep-sea oil plume resulting from the spill. A variety of metabolic genes involved in both aerobic and anaerobic hydrocarbon degradation were highly enriched in the plume compared to outside the plume, indicating a great potential for intrinsic bioremediation or natural attenuation in the deep-sea. Various other microbial functional genes relevant to carbon, nitrogen, phosphorus, sulfur and iron cycling, metal resistance, and bacteriophage replication were also enriched in the plume. Together, these results suggest that the indigenous marine microbial communities could play a significant role in biodegradation of oil spills in deep-sea environments.

  1. Conversion of chlorinated propanes by Methylosinus trichosporium OB3b expressing soluble methane monooxygenase

    OpenAIRE

    Bosma, T.; Janssen, D.B.

    1998-01-01

    Chlorinated propanes are important pollutants that may show persistent behaviour in the environment. The biotransformation of 1-chloropropane, 1,2-dichloropropane, 1,3-dichloropropane and 1,2,3-trichloropropane was studied using resting cell suspensions of Methylosinus trichosporium OB3b expressing soluble methane monooxygenase. The transformation followed first-order kinetics. The rate constants were in the order 1-chloropropane > 1,3-dichloropropane > 1,2-dichloropropane > 1,2,3-trichloropr...

  2. Characteristics of plasma plume in fiber laser welding of aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Ming; Chen, Cong; Hu, Ming; Guo, Lianbo; Wang, Zemin, E-mail: zmwang@mail.hust.edu.cn; Zeng, Xiaoyan

    2015-01-30

    Highlights: • Spectroscopic properties of fiber laser induced Al plasma plume are measured. • The plume is usually a metal vapor dominated weakly ionized plasma. • The plume is a strongly ionized plasma after laser power is higher than 5 kW. • Plasma shielding effect must be considered after laser power reaches 5 kW. • Plasma shielding effect is dominated by inverse bremsstrahlung absorption. - Abstract: To understand the laser–matter interaction in fiber laser welding of aluminum alloys, the effects of laser power on the characteristics of fiber laser induced plasma plume were studied by emission spectroscopic analysis firstly. The plasma characteristic parameters including electron temperature, electron density, ionization degree, and inverse bremsstrahlung linear absorption coefficient were computed according to the spectral data. It was found that the laser power of 5 kW is a turning point. After the laser power reaches 5 kW, the plume changes from a metal vapor dominated weakly ionized plasma to a strongly ionized plasma. The corresponding phenomena are the dramatic increase of the value of characteristic parameters and the appearance of strong plasma shielding effect. The calculation of effective laser power density demonstrated that the plasma shielding effect is dominated by inverse bremsstrahlung absorption. The finding suggested the plasma shielding effect must be considered in fiber laser welding of aluminum alloys, rather than is ignored as claimed in previous view.

  3. The Ensemble Kalman Filter for Groundwater Plume Characterization: A Case Study.

    Science.gov (United States)

    Ross, James L; Andersen, Peter F

    2018-04-17

    The Kalman filter is an efficient data assimilation tool to refine an estimate of a state variable using measured data and the variable's correlations in space and/or time. The ensemble Kalman filter (EnKF) (Evensen, 2004, 2009) is a Kalman filter variant that employs Monte Carlo analysis to define the correlations that help to refine the updated state. While use of EnKF in hydrology is somewhat limited, it has been successfully applied in other fields of engineering (e.g. oil reservoir modeling, weather forecasting). Here, EnKF is used to refine a simulated groundwater TCE plume that underlies the Tooele Army Depot-North (TEAD-N) in Utah, based on observations of TCE in the aquifer. The resulting EnKF-based assimilated plume is simulated forward in time to predict future plume migration. The correlations that underpin EnKF updating implicitly contain information about how the plume developed over time under the influence of complex site hydrology and variable source history, as they are predicated on multiple realizations of a well-calibrated numerical groundwater flow and transport model. The EnKF methodology is compared to an ordinary kriging-based assimilation method with respect to the accurate representation of plume concentrations in order to determine the relative efficacy of EnKF for water quality data assimilation. This article is protected by copyright. All rights reserved.

  4. Automated Generation of 3D Volcanic Gas Plume Models for Geobrowsers

    Science.gov (United States)

    Wright, T. E.; Burton, M.; Pyle, D. M.

    2007-12-01

    A network of five UV spectrometers on Etna automatically gathers column amounts of SO2 during daylight hours. Near-simultaneous scans from adjacent spectrometers, comprising 210 column amounts in total, are then converted to 2D slices showing the spatial distribution of the gas by tomographic reconstruction. The trajectory of the plume is computed using an automatically-submitted query to NOAA's HYSPLIT Trajectory Model. This also provides local estimates of air temperature, which are used to determine the atmospheric stability and therefore the degree to which the plume is dispersed by turbulence. This information is sufficient to construct an animated sequence of models which show how the plume is advected and diffused over time. These models are automatically generated in the Collada Digital Asset Exchange format and combined into a single file which displays the evolution of the plume in Google Earth. These models are useful for visualising and predicting the shape and distribution of the plume for civil defence, to assist field campaigns and as a means of communicating some of the work of volcano observatories to the public. The Simultaneous Algebraic Reconstruction Technique is used to create the 2D slices. This is a well-known method, based on iteratively updating a forward model (from 2D distribution to column amounts). Because it is based on a forward model, it also provides a simple way to quantify errors.

  5. SAMI3 Simulations of the Persistent May 1994 Plasmasphere Plume

    Science.gov (United States)

    Krall, J.; Huba, J.; Borovsky, J.

    2017-12-01

    We use the Naval Research Laboratory SAMI3 ionosphere/plasmasphere model[1] to explore the physics of a long-lived plasmasphere plume. A plasmasphere plume is a storm feature that extends the cold plasma that is normally trapped by the geomagnetic field (the plasmasphere) outward towards the bow shock. In the case of the May 1994 storm, the storm and the plume continued for 12 days. For the model storm, we imposed a Kp-driven Volland/Stern-Maynard/Chen potential [2-4]. Results are compared to measurements of the cold ion density from the 1989-046 spacecraft in geosynchronous orbit [5]. We find that many details of the observed plume are reproduced by SAMI3, but only if a background magnetosphere density is included as a boundary condition. We also find that high-speed, field aligned plasma flows contribute significantly to the observed plume density. [1] Huba, J. and J. Krall (2013), Modeling the plasmasphere with SAMI3, Geophys. Res. Lett., 40, 6-10, doi:10.1029/2012GL054300 [2] Volland, H. (1973), A semiempirical model of large-scale magnetospheric electric fields, Journal of Geophysical Research, 78, 171-180, doi:10.1029/JA078i001p00171 [3] Stern, D.P. (1975), The motion of a proton in the equatorial magnetosphere, Journal of Geophysical Research, 80, 595-599, doi:10.1029/JA080i004p00595 [4] Maynard, N.C., and A.J. Chen (1975), Isolated cold plasma regions: Observations and their relation to possible production mechanisms, Journal of Geophysical Research, 80, 1009-1013, doi:10.1029/JA080i007p01009 [5] Borovsky, J.E., D.T. Welling, M.F. Thomsen, and M.H. Denton (2014), Long-lived plasmaspheric drainage plumes: Where does the plasma come from?, Journal of Geophysical Research: Space Physics, 119, 6496-6520, doi:10.1002/2014JA020228 Research supported by NRL base funds.

  6. Characterization of pollution in the arctic troposphere: use of airborne and satellite data as part of the IPY/POLARCAT campaign

    International Nuclear Information System (INIS)

    Pommier, M.

    2011-01-01

    Despite improvements in observing systems and numerical models in recent decades, it remains difficult to reproduce the observed pollution episodes in the Arctic especially in summertime. One possible explanation is the underestimation of modelled ozone (O 3 ) production in forest fires plumes. Carbon monoxide (CO) is often used as a tracer of pollution transport due to its relatively long lifetime of several weeks in the troposphere. It is a reactive gas, mainly produced by the combustion of fossil fuels and vegetation burning. Moreover, since its main sink is reaction with OH radical, CO has an important role in the oxidizing power of the atmosphere it also plays an important role in the assessment of tropospheric ozone. The purpose of my thesis has been to contribute to a better understanding of transport and of the chemical mechanisms of pollutants formation in the Arctic troposphere. A combination of the new CO measurements from the IASI satellite instrument, launched in October 2006 aboard the MetOp-A and aircraft data collected during the POLARCAT campaigns of the International Polar Year, in spring and summer 2008 were used. IASI CO observations were first validated by comparison with in situ airborne measurements showing its ability to detect the evolution of high CO signatures plume as close to sources regions. The second part of the thesis used assimilation of daily IASI CO measurements (Kalman filter) in the LMDz-INCA global model to improve our understanding about sources of pollution impacting the Arctic troposphere and their transport pathways. The assimilation has improved the modelling of CO pollution episodes in the Arctic free troposphere. Model results were also evaluated using POLARCAT observations and used to examine the sensitivity of Arctic pollutant concentrations (namely the overestimation of O 3 distribution and the underestimation of peroxy acetyl nitride - PAN - distribution) to emissions from different regions and in particular the

  7. A numerical study of the plume in Cape Fear River Estuary and adjacent coastal ocean

    Science.gov (United States)

    Xia, M.; Xia, L.; Pietrafesa, L. J.

    2006-12-01

    Cape Fear River Estuary (CFRE), located in southeast North Carolina, is the only river estuary system in the state which is directly connected to the Atlantic Ocean. It is also an important nursery for economically and ecologically important juvenile fish, crabs, shrimp, and other species because of the tidal influence and saline waters. In this study, Environmental Fluid Dynamic Code (EFDC) is used to simulate the salinity plume and trajectory distribution at the mouth of the CFRE and adjacent coastal ocean. Prescribed with the climatological freshwater discharge rates in the rivers, the modeling system was used to simulate the salinity plume and trajectory distribution distribution in the mouth of the CFRE under the influence of climatological wind conditions and tidal effect. We analyzed the plume formation processes and the strong relationship between the various plume distributions with respect to the wind and river discharge in the region. The simulations also indicate that strong winds tend to reduce the surface CFRE plume size and distorting the bulge region near the estuary mouth due to enhanced wind induced surface mixing. Even moderate wind speeds could fully reverse the buoyancy-driven plume structure in CFRE under normal river discharge conditions. Tide and the river discharge also are important factors to influence the plume structure. The comparions between the distribution of salinity plume and trajectory also are discussed in the study.

  8. Modelling tools for integrating geological, geophysical and contamination data for characterization of groundwater plumes

    DEFF Research Database (Denmark)

    Balbarini, Nicola

    the contaminant plume in a shallow and a deep plume. These plumes have different chemical characteristics and different migration paths to the stream. This has implications for the risk assessment of the stream and groundwater in the area. The difficulty of determining groundwater flow paths means that it is also...... receptors, including streams. Key risk assessment parameters, such as contaminant mass discharge estimates, and tools are then used to evaluate the risk. The cost of drilling often makes investigations of large and/or deep contaminant plumes unfeasible. For this reason, it is important to develop cost...... organic compounds, including pharmaceutical compounds and chlorinated ethenes. The correlation between DCIP and organic compounds is indirect and depends on the chemical composition of the contaminant plume and the transport processes. Thus, the correlations are site specific and may change between...

  9. Wind tunnel experiments on cooling tower plumes. Pt. 2

    International Nuclear Information System (INIS)

    Andreopoulos, J.

    1986-01-01

    The basic characteristics of plumes issuing into a boundary layer type of cross flow are reported. The flow can be considered as an interaction between two vorticity fields with different length scales and turbulence intensities. The large eddies of the oncoming boundary layer are responsible for the observed sudden changes in the plume direction. The type of structures emanating the tower depends on the instantaneous velocity ratio. Mean velocities and normal velocity gradients are smaller than in the case of uniform cross-flow (Andreopoulos, 1986) and therefore the measured turbulence intensities were lower too. The cross-stream turbulence brings high momentum fluid into the wake region and the velocity defect decays very rapidly. Dilution of the plumes takes place faster in the presence of external turbulence than in the case with uniform cross-flow. The spreading rate is increased dramatically by the external turbulence which causes different effects on the hydrodynamic and thermal fields. (orig.) [de

  10. The metatranscriptome of a deep-sea hydrothermal plume is dominated by water column methanotrophs and lithotrophs.

    Science.gov (United States)

    Lesniewski, Ryan A; Jain, Sunit; Anantharaman, Karthik; Schloss, Patrick D; Dick, Gregory J

    2012-12-01

    Microorganisms mediate geochemical processes in deep-sea hydrothermal vent plumes, which are a conduit for transfer of elements and energy from the subsurface to the oceans. Despite this important microbial influence on marine geochemistry, the ecology and activity of microbial communities in hydrothermal plumes is largely unexplored. Here, we use a coordinated metagenomic and metatranscriptomic approach to compare microbial communities in Guaymas Basin hydrothermal plumes to background waters above the plume and in the adjacent Carmen Basin. Despite marked increases in plume total RNA concentrations (3-4 times) and microbially mediated manganese oxidation rates (15-125 times), plume and background metatranscriptomes were dominated by the same groups of methanotrophs and chemolithoautotrophs. Abundant community members of Guaymas Basin seafloor environments (hydrothermal sediments and chimneys) were not prevalent in the plume metatranscriptome. De novo metagenomic assembly was used to reconstruct genomes of abundant populations, including Marine Group I archaea, Methylococcaceae, SAR324 Deltaproteobacteria and SUP05 Gammaproteobacteria. Mapping transcripts to these genomes revealed abundant expression of genes involved in the chemolithotrophic oxidation of ammonia (amo), methane (pmo) and sulfur (sox). Whereas amo and pmo gene transcripts were abundant in both plume and background, transcripts of sox genes for sulfur oxidation from SUP05 groups displayed a 10-20-fold increase in plumes. We conclude that the biogeochemistry of Guaymas Basin hydrothermal plumes is mediated by microorganisms that are derived from seawater rather than from seafloor hydrothermal environments such as chimneys or sediments, and that hydrothermal inputs serve as important electron donors for primary production in the deep Gulf of California.

  11. Measurement of polynuclear aromatic hydrocarbon concentrations in the plume of Kuwait oil well fires

    International Nuclear Information System (INIS)

    Olsen, K.B.; Wright, C.W.; Veverka, C.; Ball, J.C.; Stevens, R.

    1995-03-01

    Following their retreat from Kuwait during February and March of 1991, the Iraqi Army set fire to over 500 oil wells dispersed throughout the Kuwait oil fields. During the period of sampling from July to August 1991, it was estimated that between 3.29 x 10 6 barrels per day of crude oil were combusted. The resulting fires produced several plumes of black and white smoke that coalesced to form a composite ''super'' plume. Because these fires were uncontrolled, significant quantities of organic materials were dispersed into the atmosphere and drifted throughout the Middle East. The organic particulants associated with the plume of the oil well fires had a potential to be rich in polynuclear aromatic hydrocarbon (PAH) compounds. Based on the extreme mutagenic and carcinogenic activities of PAHs found in laboratory testing, a serious health threat to the population of that region potentially existed. Furthermore, the Kuwait oil fire plumes represented a unique opportunity to study the atmospheric chemistry associated with PAHs in the plume. If samples were collected near the plume source and from the plume many kilometers downwind from the source, comparisons could be made to better understand atmospheric reactions associated with particle-bound and gas-phase PAHs. To help answer health-related concerns and to better understand the fate and transport of PAHs in an atmospheric environment, a sampling and analysis program was developed

  12. Spatial and Temporal Changes in Air Pollution Along the Gulf Coast Observed During BRACE: A Case Study of the Land-Sea Breeze

    Science.gov (United States)

    Wellman, D.; Luke, W.; Arnold, J.; Watson, T.; Gunter, L.

    2003-12-01

    NOAA's Air Resources Laboratory conducted airborne measurements of trace gases and aerosols in the Bay Region Atmospheric Chemistry Experiment (BRACE) using the NOAA Twin Otter. The Twin Otter flew more than 90 hours in 21 flights in and around the Tampa metropolitan region in May, 2002, at altitudes of 60-3000 m MSL. Flights were conducted over rural and suburban areas, over the centers of Tampa and St. Petersburg, and over Tampa Bay and the Gulf of Mexico. One objective of the aircraft flights was to investigate the role of the sea breeze circulation in determining patterns of nutrient deposition and pollutant loads in the Tampa Bay watershed. Results will be presented from a May 8 flight designed to investigate the effect of the sea breeze recirculation upon Tampa's air quality. The Twin Otter took off at 1425 UTC and after performing a spiral ascent over the Sydney ground site, proceeded to fly north, at 200 feet above mean sea level (MSL) just off the Gulf coast, west of St. Petersburg. Back trajectory analysis suggested the dominance of a northerly rotation in the sea breeze; thus, air sampled over the Gulf passed some hours earlier to the south of the Tampa metropolitan area, in an area largely devoid of major pollution sources, before being advected eastward in the afternoon return flow. Ozone levels in this air mass ranged from 40 to 50 ppbv. Farther north the Twin Otter encountered the advected urban plume from Tampa, displaced to the north by the combination of southeasterly sea breeze flow and westerly return flow, and tracked this plume inland. Ozone levels quickly jumped to 60 ppbv, and increased to as high as 90 ppbv as photochemical processing continued in the advected plume. Nitric acid levels, which approached 4 ppbv in the aged urban air at the coast, dropped rapidly to as low as 1 ppbv inland. A final flight leg to the east of downtown Tampa encountered fresh anthropogenic pollution from the afternoon rush hour; ozone was rapidly produced in the

  13. Simulation of Mexico City plumes during the MIRAGE-Mex field campaign using the WRF-Chem model

    Directory of Open Access Journals (Sweden)

    X. Tie

    2009-07-01

    Full Text Available The quantification of tropospheric O3 production in the downwind of the Mexico City plume is a major objective of the MIRAGE-Mex field campaign. We used a regional chemistry-transport model (WRF-Chem to predict the distribution of O3 and its precursors in Mexico City and the surrounding region during March 2006, and compared the model with in-situ aircraft measurements of O3, CO, VOCs, NOx, and NOy concentrations. The comparison shows that the model is capable of capturing the timing and location of the measured city plumes, and the calculated variability along the flights is generally consistent with the measured results, showing a rapid increase in O3 and its precursors when city plumes are detected. However, there are some notable differences between the calculated and measured values, suggesting that, during transport from the surface of the city to the outflow plume, ozone mixing ratios are underestimated by about 0–25% during different flights. The calculated O3-NOx, O3-CO, and O3-NOz correlations generally agree with the measured values, and the analyses of these correlations suggest that photochemical O3 production continues in the plume downwind of the city (aged plume, adding to the O3 already produced in the city and exported with the plume. The model is also used to quantify the contributions to OH reactivity from various compounds in the aged plume. This analysis suggests that oxygenated organics (OVOCs have the highest OH reactivity and play important roles for the O3 production in the aging plume. Furthermore, O3 production per NOx molecule consumed (O3 production efficiency is more efficient in the aged plume than in the young plume near the city. The major contributor to the high O3 production efficiency in the aged plume is the

  14. A numerical study for the assessment of pollutant dispersion from Kostolac B power plant to Viminacium for different atmospheric conditions

    Directory of Open Access Journals (Sweden)

    Kozić Mirko S.

    2015-01-01

    Full Text Available The level of pollution concentration to the archaeological site Viminacium caused by the stack of Kostolac B power plant is analyzed using CFD software. The wind is directed from the stack toward Viminacium-Archaeological Site, Therma and Viminacium - Museum. Three different meteorological conditions resulting in fanning, fumigating and looping plume are modelled. The temperature gradient as the most important factor defining the conditions of the atmosphere is included through the appropriate boundary conditions. It is shown that concentrations of the pollutants on the objects of Viminacium are very low. It can be attributed to the stack height and high temperature of the smoke at its exit. It also indicates that other sources of pollution such as open ash dumps and acid rain should be checked.

  15. Cone penetrometer tests and HydroPunch sampling: A screening technique for plume definition

    International Nuclear Information System (INIS)

    Smolley, M.; Kappmeyer, J.C.

    1991-01-01

    Cone penetrometer tests and HydroPunch sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of the these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost-effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program

  16. Emplacement of zero-valent metal for remediation of deep contaminant plumes

    International Nuclear Information System (INIS)

    Hubble, D.W.; Gillham, R.W.; Cherry, J.A.

    1997-01-01

    Some groundwater plumes containing chlorinated solvent contaminants are found to be so deep that current in situ remediation technologies cannot be economically applied. Also, source zones are often found to be too deep for removal or inaccessible due to surface features. Plumes emanating from these sources require containment or treatment. Containment technologies are available for shallow sites (< 15 m) and are being developed for greater depths. However, it is important to advance the science of reactive treatment - both for cut off of plumes and to contain and treat source zones. Zero-valent metal technology has been used for remediation of solvent plumes at sites in Canada, the UK and at several industrial and military sites in the USA. To date, all of the plumes treated with zero-valent metal (granular iron) have been at depths less than 15 m. This paper gives preliminary results of research into methods to emplace granular iron at depths in the range of 15 to 60 m. The study included review of available and emerging methods of installing barrier or reactive material and the selection, preliminary design and costing of several methods. The design of a treatment system for a 122 m wide PCE plume that, immediately down gradient from its source, extends from a depth of 24 to 37 m below the ground surface is used as a demonstration site. Both Permeable Reactive Wall and Funnel-and-Gate trademark systems were considered. The emplacement methods selected for preliminary design and costing were slurry wall, driven/vibrated beam, deep soil mixing and hydrofracturing injection. For each of these methods, the iron must be slurried for ease of pumping and placement using biodegradable polymer viscosifiers that leave the iron reactive

  17. Lithosphere erosion and continental breakup : Interaction of extension, plume upwelling and melting

    NARCIS (Netherlands)

    Lavecchia, Alessio; Thieulot, Cedric; Beekman, Fred; Cloetingh, Sierd; Clark, Stuart

    2017-01-01

    We present the results of thermo-mechanical modelling of extension and breakup of a heterogeneous continental lithosphere, subjected to plume impingement in presence of intraplate stress field. We incorporate partial melting of the extending lithosphere, underlying upper mantle and plume, caused by

  18. Solar Coronal Plumes and the Fast Solar Wind Bhola N. Dwivedi1 ...

    Indian Academy of Sciences (India)

    Is there any contribution of plume plasma to the fast SW streams at all? ..... but to a slow diminution of the reconnection activity, presumably with the effect ... might think, even if the thermal energy could be dumped at the base of the plume,.

  19. Magnetic Detachment and Plume Control in Escaping Magnetized Plasma

    International Nuclear Information System (INIS)

    Schmit, P.F.; Fisch, N.J.

    2008-01-01

    The model of two-fluid, axisymmetric, ambipolar magnetized plasma detachment from thruster guide fields is extended to include plasmas with non-zero injection angular velocity profiles. Certain plasma injection angular velocity profiles are shown to narrow the plasma plume, thereby increasing exhaust efficiency. As an example, we consider a magnetic guide field arising from a simple current ring and demonstrate plasma injection schemes that more than double the fraction of useful exhaust aperture area, more than halve the exhaust plume angle, and enhance magnetized plasma detachment

  20. Plasma Observations During the Mars Atmospheric Plume Event of March-April 2012

    Science.gov (United States)

    Andrews, D. J.; Barabash, S.; Edberg, N. J. T.; Gurnett, D. A.; Hall, B. E. S.; Holmstrom, M.; Lester, M.; Morgan, D. D.; Opgenoorth, H. J.; Ramstad, R.; hide

    2016-01-01

    We present initial analysis and conclusions from plasma observations made during the reported Mars Dust plume event of March - April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude plume over the Martian dawn terminator [Sanchez-Lavega7 et al., Nature, 2015, doi:10.1038nature14162], the origin of which remains to be explained. We report on in-situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the surface region, but at the opposing terminator. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that a similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.

  1. Test data from small solid propellant rocket motor plume measurements (FA-21)

    Science.gov (United States)

    Hair, L. M.; Somers, R. E.

    1976-01-01

    A program is described for obtaining a reliable, parametric set of measurements in the exhaust plumes of solid propellant rocket motors. Plume measurements included pressures, temperatures, forces, heat transfer rates, particle sampling, and high-speed movies. Approximately 210,000 digital data points and 15,000 movie frames were acquired. Measurements were made at points in the plumes via rake-mounted probes, and on the surface of a large plate impinged by the exhaust plume. Parametric variations were made in pressure altitude, propellant aluminum loading, impinged plate incidence angle and distance from nozzle exit to plate or rake. Reliability was incorporated by continual use of repeat runs. The test setup of the various hardware items is described along with an account of test procedures. Test results and data accuracy are discussed. Format of the data presentation is detailed. Complete data are included in the appendix.

  2. On the Color of the Orinoco River Plume

    Science.gov (United States)

    Odriozola, A.; Muller-Karger, F.; Carder, K.; Hu, C.; Varela, R.

    2005-05-01

    In situ measurements were used to study the bio-optical properties of marine waters within the Gulf of Paria (GOP, Venezuela) and in the Southeastern Caribbean Sea (SEC) as they are affected by the seasonal discharge of the Orinoco River plume. The main purpose of this study was to determine the impact of colored dissolved organic matter (CDOM) (also known as Gelbstoff), phytoplankton, and total suspended matter (TSM) in the color of the Orinoco River plume. This information is essential for regional ocean color algorithms development. Salinity and silica values indicate that the GOP and SEC waters were under the influence of the Orinoco River plume during both seasons. This riverine influence resulted in high values of Gelbstoff absorption, ag(λ), which contributed to up to 90% of the total absorption at 440 nm in both the GOP and SEC regardless of the season. Phytoplankton absorption contributions were normally around 5%, but during the dry season these values reached 20% in the SEC. Ratios of ag(440) to ph(440) were extremely large, with most of the values ranging from 10 to 50. Due to the strong absorption by Gelbstoff, light at the blue wavelengths (412 nm, 440 nm and 490 nm) was attenuated to 1% of the subsurface irradiance in the first 5 m of the water column within the GOP, and in the first 10 m of the water column in the SEC. Furthermore, the absorption by Gelbstoff significantly decreased the water leaving radiance (Lw(λ)) in the blue wavelengths along the Orinoco River plume. As ag(λ) relatively decreased from the GOP to the SEC (mean ~1.6 m-1 and mean ~0.9 m-1, respectively), a shift in the maximum peak of Rrs(λ) spectra (Rrsmax(λ)), towards shorter wavelengths (from ~ 580 nm to ~500 nm) was observed. Similar to Gelbstoff, concentrations of TSM normally decreased from the stations near the Delta to the stations in the SEC. The impact of TSM on the color of the Orinoco plume was represented by a reduction in the magnitude of Rrsmax(λ) of ~50% going

  3. Plume characteristics and dynamics of UV and IR laser-desorbed oligonucleotides.

    Science.gov (United States)

    Merrigan, Tony L; Timson, David J; Hunniford, C Adam; Catney, Martin; McCullough, Robert W

    2012-05-01

    Laser desorption of dye-tagged oligonucleotides was studied using laser-induced fluorescence imaging. Desorption with ultra violet (UV) and infra-red (IR) lasers resulted in forward directed plumes of molecules. In the case of UV desorption, the initial shot desorbed approximately seven-fold more material than subsequent shots. In contrast, the initial shot in IR desorption resulted in the ejection of less material compared to subsequent shots and these plumes had a component directed along the path of the laser. Thermal equilibrium of the molecules in the plume was achieved after approximately 25 μs with a spread in molecular temperature which was described by a modified Maxwell-Boltzmann equation. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Plume rise predictions

    International Nuclear Information System (INIS)

    Briggs, G.A.

    1976-01-01

    Anyone involved with diffusion calculations becomes well aware of the strong dependence of maximum ground concentrations on the effective stack height, h/sub e/. For most conditions chi/sub max/ is approximately proportional to h/sub e/ -2 , as has been recognized at least since 1936 (Bosanquet and Pearson). Making allowance for the gradual decrease in the ratio of vertical to lateral diffusion at increasing heights, the exponent is slightly larger, say chi/sub max/ approximately h/sub e/ - 2 . 3 . In inversion breakup fumigation, the exponent is somewhat smaller; very crudely, chi/sub max/ approximately h/sub e/ -1 . 5 . In any case, for an elevated emission the dependence of chi/sub max/ on h/sub e/ is substantial. It is postulated that a really clever ignorant theoretician can disguise his ignorance with dimensionless constants. For most sources the effective stack height is considerably larger than the actual source height, h/sub s/. For instance, for power plants with no downwash problems, h/sub e/ is more than twice h/sub s/ whenever the wind is less than 10 m/sec, which is most of the time. This is unfortunate for anyone who has to predict ground concentrations, for he is likely to have to calculate the plume rise, Δh. Especially when using h/sub e/ = h/sub s/ + Δh instead of h/sub s/ may reduce chi/sub max/ by a factor of anywhere from 4 to infinity. Factors to be considered in making plume rise predictions are discussed

  5. SNIFFER: An aerial platform for the plume phase of a nuclear emergency

    Directory of Open Access Journals (Sweden)

    Cisbani E.

    2012-04-01

    Full Text Available When a nuclear or radiological accident results in a release of a radioactive plume, AGS (Aerial Gamma Spectrometry systems used in many countries, equipped with passive detectors, can help in giving quantitative assessment on the radiological situation (land surface contamination level only when the air contamination due to the passage of the travelling plume has become negligible. To overcome this limitation, the Italian Institute of Health has developed and implemented a multi purpose air sampling system based on a fixed wing aircraft, for time-effective, large areas radiological surveillance (to face radiological emergency and to support homeland security. A fixed wing aircraft (Sky Arrow 650 with the front part of the fuselage properly adapted to house the detection equipment has been equipped with a compact air sampling line where the isokinetic sampling is dynamically maintained. Aerosol is collected on a Teflon® filter positioned along the line and hosted on a rotating 4-filters disk. A complex of detectors allows radionuclide identification in the collected aerosol samples. A correlated analysis of these two detectors data allows a quantitative measurement of air as well as ground surface concentration of gamma emitting radioisotopes. Environmental sensors and a GPS receiver support the characterization of the sampling conditions and the temporal and geolocation of the acquired data. Acquisition and control system based on compact electronics and real time software that operate the sampling line actuators, guarantee the dynamical isokinetic condition, and acquire the detectors and sensor data. The system is also equipped with other sampling lines to provide information on the concentration of other chemical pollutants. Operative flights have been carried out in the last years, and performances and results are presented.

  6. Soil pollution by oxidation of tailings from toxic spill of a pyrite mine

    International Nuclear Information System (INIS)

    Simon, M.; Martin, F.; Ortiz, I.; Garcia, I.; Fernandez, J.; Fernandez, E.; Dorronsoro, C.; Aguilar, J.

    2001-01-01

    On the 25th April 1998, toxic water and tailings from a pyrite mine of Aznalcollar (southern Spain) spilled into the Agrio and Guadiamar River Basin affecting some 40 km 2 . In five sectors throughout the basin, we monitored the physical and chemical properties of the tailings as well as the degree of pollution in the soils on four different sampling dates: 5 May, 20 May, 4 June and 22 July 1998. The characteristics of the tailings deposited on the soils are shown to be related to distance from the spill. The oxidation rate of the tailings and the solubilization of the pollutant elements were more pronounced in the middle and lower sectors of the basin, where the particle size was finer, the sulfur content higher and the bulk density less. The increases in water-soluble sulfates, Zn, Cd and Cu were very rapid (the highest values being reached 25 days after the spill) and intense (reaching 45% of the total Cu, 65% of the total Zn and Cd). Meanwhile, the increases in water-soluble As, Bi, Sb, Pb and Tl were far lower (ranging between 0.002% of the total Tl and 2.5% of the total As) and less rapid in the case of As, Bi and Pb (the highest values for these elements being reached 40 days after the spill). These soluble elements infiltrated the soils with the rainwater, swiftly augmenting the soil pollution. Twenty-five days after the spill, when the rainfall ranged between 45 and 63 mm, the first 10-cm of the soils in the middle and lower sectors of the basin exceeded the maximum concentration permitted for agricultural soils in Zn, Cu and Tl. At 40 days after the spill, when the rainfall ranged between 60 and 89 mm, all the soils reached or exceeded the maximum permitted concentrations for As and Tl. Nevertheless, the pollutants tended to concentrate in the first 10 cm of the soils without seriously contaminating either the subsoil or the groundwaters. Consequently, a rapid removal of the tailings and the ploughing of the first 25-30 cm of the soils would be urgent

  7. Model Intercomparison Study to Investigate a Dense Contaminant Plume in a Complex Hydrogeologic System

    International Nuclear Information System (INIS)

    Williams, Mark D.; Cole, Charles R.; Foley, Michael G.; Zinina, Galina A.; Zinin, Alexander I.; Vasil'Kova, Nelly A.; Samsonova, Lilia M.

    2001-01-01

    A joint Russian and U.S. model intercomparison study was undertaken for developing more realistic contaminant transport models of the Mayak Site, Southern Urals. The test problems were developed by the Russian Team based on their experience modeling contaminant migration near Lake Karachai. The intercomparison problems were designed to address lake and contaminant plume interactions, as well as river interactions and plume density effects. Different numerical codes were used. Overall there is good agreement between the results of both models. Features shown by both models include (1) the sinking of the plume below the lake, (2) the raising of the water table in the fresh water adjacent to the lake in response to the increased pressure from the dense plume, and (3) the formation of a second sinking plume in an area where evapotranspiration exceeded infiltration, thus increasing the solute concentrations above the source (i.e., lake) values

  8. Thermal History of CBb Chondrules and Cooling Rate Distributions of Ejecta Plumes

    Science.gov (United States)

    Hewins, R. H.; Condie, C.; Morris, M.; Richardson, M. L. A.; Ouellette, N.; Metcalf, M.

    2018-03-01

    It has been proposed that some meteorites, CB and CH chondrites, contain material formed as a result of a protoplanetary collision during accretion. Their melt droplets (chondrules) and FeNi metal are proposed to have formed by evaporation and condensation in the resulting impact plume. We observe that the skeletal olivine (SO) chondrules in CBb chondrites have a blebby texture and an enrichment in refractory elements not found in normal chondrules. Because the texture requires complete melting, their maximum liquidus temperature of 1928 K represents a minimum temperature for the putative plume. Dynamic crystallization experiments show that the SO texture can be created only by brief reheating episodes during crystallization, giving a partial dissolution of olivine. The ejecta plume formed in a smoothed particle hydrodynamics simulation served as the basis for 3D modeling with the adaptive mesh refinement code FLASH4.3. Tracer particles that move with the fluid cells are used to measure the in situ cooling rates. Their cooling rates are ∼10,000 K hr‑1 briefly at peak temperature and, in the densest regions of the plume, ∼100 K hr‑1 for 1400–1600 K. A small fraction of cells is seen to be heating at any one time, with heating spikes explained by the compression of parcels of gas in a heterogeneous patchy plume. These temperature fluctuations are comparable to those required in crystallization experiments. For the first time, we find an agreement between experiments and models that supports the plume model specifically for the formation of CBb chondrules.

  9. The importance of vertical resolution in the free troposphere for modeling intercontinental plumes

    Directory of Open Access Journals (Sweden)

    J. Zhuang

    2018-05-01

    Full Text Available Chemical plumes in the free troposphere can preserve their identity for more than a week as they are transported on intercontinental scales. Current global models cannot reproduce this transport. The plumes dilute far too rapidly due to numerical diffusion in sheared flow. We show how model accuracy can be limited by either horizontal resolution (Δx or vertical resolution (Δz. Balancing horizontal and vertical numerical diffusion, and weighing computational cost, implies an optimal grid resolution ratio (Δx ∕ Δzopt ∼ 1000 for simulating the plumes. This is considerably higher than current global models (Δx ∕ Δz ∼ 20 and explains the rapid plume dilution in the models as caused by insufficient vertical resolution. Plume simulations with the Geophysical Fluid Dynamics Laboratory Finite-Volume Cubed-Sphere Dynamical Core (GFDL-FV3 over a range of horizontal and vertical grid resolutions confirm this limiting behavior. Our highest-resolution simulation (Δx ≈ 25 km, Δz  ≈  80 m preserves the maximum mixing ratio in the plume to within 35 % after 8 days in strongly sheared flow, a drastic improvement over current models. Adding free tropospheric vertical levels in global models is computationally inexpensive and would also improve the simulation of water vapor.

  10. Numerical study of single and two interacting turbulent plumes in atmospheric cross flow

    Science.gov (United States)

    Mokhtarzadeh-Dehghan, M. R.; König, C. S.; Robins, A. G.

    The paper presents a numerical study of two interacting full-scale dry plumes issued into neutral boundary layer cross flow. The study simulates plumes from a mechanical draught cooling tower. The plumes are placed in tandem or side-by-side. Results are first presented for plumes with a density ratio of 0.74 and plume-to-crosswind speed ratio of 2.33, for which data from a small-scale wind tunnel experiment were available and were used to assess the accuracy of the numerical results. Further results are then presented for the more physically realistic density ratio of 0.95, maintaining the same speed ratio. The sensitivity of the results with respect to three turbulence models, namely, the standard k- ɛ model, the RNG k- ɛ model and the Differential Flux Model (DFM) is presented. Comparisons are also made between the predicted rise height and the values obtained from existing integral models. The formation of two counter-rotating vortices is well predicted. The results show good agreement for the rise height predicted by different turbulence models, but the DFM predicts temperature profiles more accurately. The values of predicted rise height are also in general agreement. However, discrepancies between the present results for the rise height for single and multiple plumes and the values obtained from known analytical relations are apparent and possible reasons for these are discussed.

  11. Cross shore transport by wind-driven turbidity plumes in western Lake Superior*

    Science.gov (United States)

    Turbidity plumes frequently occur in the western arm of Lake Superior and may represent a significant cross shelf transport mechanism for sediment, nutrient and biota. We characterize a plume that formed in late April 2016 using observations from in situ sensors and remote sensin...

  12. In situ and laboratory studies on the fate of specific organic compounds in an anaerobic landfill leachate plume, 1. Experimental conditions and fate of phenolic compounds

    Science.gov (United States)

    Nielsen, Per H.; Albrechtsen, Hans-Jørgen; Heron, Gorm; Christensen, Thomas H.

    1995-11-01

    The transformation of specific organic compounds was investigated by in situ and laboratory experiments in an anaerobic landfill leachate pollution plume at four different distances from the landfill. This paper presents the experimental conditions in the in situ microcosm and laboratory batch microcosm experiments performed and the results on the fate of 7 phenolic compounds. Part 2 of this series of papers, also published in this issue, presents the results on the fate of 8 aromatic compounds and 4 chlorinated aliphatic compounds. The redox conditions in the plume were characterized as methanogenic, Fe(III)-reducing and NO 3--reducing by the redox sensitive species present in groundwater and sediment and by bioassays. With a few exceptions the aquifer redox conditions were maintained throughout the experiments as monitored by redox sensitive species present in groundwater during the experiments, by redox sensitive species present in the sediment after the experiments and by bioassays performed after the experiments. Transformation of nitrophenol was very fast close to the landfill in strongly reducing conditions, while transformation was slower in the more oxidized part of the plume. Lag phases for the nitrophenols were short (maximum 10 days). Phenol was only transformed in the more distant part of the plume in experiments where NO 3-, Fe(III) and Mn(IV) reduction was dominant. Lag phases for phenol were either absent or lasted up to 2 months. Dichlorophenols were only transformed in experiments representing strongly reducing, presumably methanogenic, redox conditions close to the landfill after lag phases of up to 3 months. Transformation of o-cresol was not observed in any of the experiments throughout the plume. Generally, there was good accordance between the results obtained by in situ and laboratory experiments, both concerning redox conditions and the fate of the phenolic compounds. However, for phenol and 2,4-dichlorophenol, transformation was observed

  13. Dispersion of Exhalation Pollutants in a Two-bed Hospital Ward with a Downward Ventilation System

    DEFF Research Database (Denmark)

    Qian, Hua; Nielsen, Peter V.; Hyldgård, Carl-Erik

    2006-01-01

    The Centers for Disease Control and Prevention has recommended the use of downward ventilation systems in isolation rooms to reduce the risk of cross-infection from airborne transmissible diseases. The expected airflow pattern of a downward ventilation design would supply cooler and slightly...... to investigate the airflow pattern and pollutant dispersion in the test ward. Based on both experimental and numerical results, the laminar airflow pattern was shown to be impossible to achieve due to turbulent flow mixing and flow entrainment into the supply air stream. The thermal plumes produced above people...... were found to induce flow mixing. We also studied the effects of the locations of the supply and extraction openings on both the flow pattern and pollutant exposure level in the occupied zone. A number of practical recommendations are suggested....

  14. Advances in the Validation of Satellite-Based Maps of Volcanic Sulfur Dioxide Plumes

    Science.gov (United States)

    Realmuto, V. J.; Berk, A.; Acharya, P. K.; Kennett, R.

    2013-12-01

    The monitoring of volcanic gas emissions with gas cameras, spectrometer arrays, tethersondes, and UAVs presents new opportunities for the validation of satellite-based retrievals of gas concentrations. Gas cameras and spectrometer arrays provide instantaneous observations of the gas burden, or concentration along an optical path, over broad sections of a plume, similar to the observations acquired by nadir-viewing satellites. Tethersondes and UAVs provide us with direct measurements of the vertical profiles of gas concentrations within plumes. This presentation will focus on our current efforts to validate ASTER-based maps of sulfur dioxide plumes at Turrialba and Kilauea Volcanoes (located in Costa Rica and Hawaii, respectively). These volcanoes, which are the subjects of comprehensive monitoring programs, are challenging targets for thermal infrared (TIR) remote sensing due the warm and humid atmospheric conditions. The high spatial resolution of ASTER in the TIR (90 meters) allows us to map the plumes back to their source vents, but also requires us to pay close attention to the temperature and emissivity of the surfaces beneath the plumes. Our knowledge of the surface and atmospheric conditions is never perfect, and we employ interactive mapping techniques that allow us to evaluate the impact of these uncertainties on our estimates of plume composition. To accomplish this interactive mapping we have developed the Plume Tracker tool kit, which integrates retrieval procedures, visualization tools, and a customized version of the MODTRAN radiative transfer (RT) model under a single graphics user interface (GUI). We are in the process of porting the RT calculations to graphics processing units (GPUs) with the goal of achieving a 100-fold increase in the speed of computation relative to conventional CPU-based processing. We will report on our progress with this evolution of Plume Tracker. Portions of this research were conducted at the Jet Propulsion Laboratory

  15. Volcanic Plume Elevation Model Derived From Landsat 8: examples on Holuhraun (Iceland) and Mount Etna (Italy)

    Science.gov (United States)

    de Michele, Marcello; Raucoules, Daniel; Arason, Þórður; Spinetti, Claudia; Corradini, Stefano; Merucci, Luca

    2016-04-01

    The retrieval of both height and velocity of a volcanic plume is an important issue in volcanology. As an example, it is known that large volcanic eruptions can temporarily alter the climate, causing global cooling and shifting precipitation patterns; the ash/gas dispersion in the atmosphere, their impact and lifetime around the globe, greatly depends on the injection altitude. Plume height information is critical for ash dispersion modelling and air traffic security. Furthermore, plume height during explosive volcanism is the primary parameter for estimating mass eruption rate. Knowing the plume altitude is also important to get the correct amount of SO2 concentration from dedicated spaceborne spectrometers. Moreover, the distribution of ash deposits on ground greatly depends on the ash cloud altitude, which has an impact on risk assessment and crisis management. Furthermore, a spatially detailed plume height measure could be used as a hint for gas emission rate estimation and for ash plume volume researches, which both have an impact on climate research, air quality assessment for aviation and finally for the understanding of the volcanic system itself as ash/gas emission rates are related to the state of pressurization of the magmatic chamber. Today, the community mainly relies on ground based measurements but often they can be difficult to collect as by definition volcanic areas are dangerous areas (presence of toxic gases) and can be remotely situated and difficult to access. Satellite remote sensing offers a comprehensive and safe way to estimate plume height. Conventional photogrammetric restitution based on satellite imagery fails in precisely retrieving a plume elevation model as the plume own velocity induces an apparent parallax that adds up to the standard parallax given by the stereoscopic view. Therefore, measurements based on standard satellite photogrammeric restitution do not apply as there is an ambiguity in the measurement of the plume position

  16. Characterizing the solar reflection from wildfire smoke plumes using airborne multiangle measurements

    Science.gov (United States)

    Gatebe, C. K.; Varnai, T.; Gautam, R.; Poudyal, R.; Singh, M. K.

    2016-12-01

    To help better understand forest fire smoke plumes, this study examines sunlight reflected from plumes that were observed over Canada during the ARCTAS campaign in summer 2008. In particular, the study analyzes multiangle and multispectral measurements of smoke scattering by the airborne Cloud Absorption Radiometer (CAR). In combination with other in-situ and remote sensing information and radiation modeling, CAR data is used for characterizing the radiative properties and radiative impact of smoke particles—which inherently depend on smoke particle properties that influence air quality. In addition to estimating the amount of reflected and absorbed sunlight, the work includes using CAR data to create spectral and broadband top-of-atmosphere angular distribution models (ADMs) of solar radiation reflected by smoke plumes, and examining the sensitivity of such angular models to scene parameters. Overall, the results help better understand the radiative properties and radiative effects of smoke particles, and are anticipated to help better interpret satellite data on smoke plumes.

  17. Chernobyl plume: commentary about a discharge

    International Nuclear Information System (INIS)

    Anon

    2011-01-01

    The Paris appeal court has dismissed the charges against P. Pellerin who was the head of the SCIRP (service of protection against the ionizing radiations) at the time of the Chernobyl accident. The appeal court confirms that P.Pellerin never said that the Chernobyl plume stopped at the French border but instead he said that the Chernobyl plume entered the French territory but the radioactivity level was so low that it was unnecessary to take sanitary steps. P.Pellerin based his decision on the results of 6500 controls performed by the SCIRP in May and June 1986. Seven other European countries recommended not to take sanitary measures. The increase of thyroid cancers that has happened in all industrialized countries and that affect only adults, can not due to Chernobyl contamination because child's thyroid is far more sensitive than adult's. The increase of thyroid cancer is mainly due to a better detection of the tumors. (A.C.)

  18. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M.  C.; Hewitt, I. J.; Wells, A. J.

    2015-01-01

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.

  19. SRS reactor stack plume marking tests

    International Nuclear Information System (INIS)

    Petry, S.F.

    1992-03-01

    Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart

  20. Channelization of plumes beneath ice shelves

    KAUST Repository

    Dallaston, M. C.

    2015-11-11

    © 2015 Cambridge University Press. We study a simplified model of ice-ocean interaction beneath a floating ice shelf, and investigate the possibility for channels to form in the ice shelf base due to spatial variations in conditions at the grounding line. The model combines an extensional thin-film description of viscous ice flow in the shelf, with melting at its base driven by a turbulent ocean plume. Small transverse perturbations to the one-dimensional steady state are considered, driven either by ice thickness or subglacial discharge variations across the grounding line. Either forcing leads to the growth of channels downstream, with melting driven by locally enhanced ocean velocities, and thus heat transfer. Narrow channels are smoothed out due to turbulent mixing in the ocean plume, leading to a preferred wavelength for channel growth. In the absence of perturbations at the grounding line, linear stability analysis suggests that the one-dimensional state is stable to initial perturbations, chiefly due to the background ice advection.