WorldWideScience

Sample records for windy atmospheric environments

  1. Evaluating the Coda Phase Delay Method for Determining Temperature Ratios in Windy Environments

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Sarah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bowman, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rodgers, Arthur [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seastrand, Douglas [National Security Technologies, LLC. (NSTec), Las Vegas, NV (United States)

    2017-07-01

    We evaluate the acoustic coda phase delay method for estimating changes in atmospheric phenomena in realistic environments. Previous studies verifying the method took place in an environment with negligible wind. The equation for effective sound speed, which the method is based upon, shows that the influence of wind is equal to the square of temperature. Under normal conditions, wind is significant and therefore cannot be ignored. Results from this study con rm the previous statement. The acoustic coda phase delay method breaks down in non-ideal environments, namely those where wind speed and direction varies across small distances. We suggest that future studies make use of gradiometry to better understand the effect of wind on the acoustic coda and subsequent phase delays.

  2. 2015 Big Windy, Oregon 4-Band 8 Bit Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are LiDAR orthorectified aerial photographs (8-bit GeoTIFF format) within the Oregon Lidar Consortium Big Windy project area. The imagery coverage is...

  3. 2015 Oregon Department of Geology and Mineral Industries (DOGAMI) Oregon Lidar: Big Windy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Quantum Spatial collected Light Detection and Ranging (LiDAR) data for the Oregon LiDAR Consortium (OLC) Big Windy 2015 study area. This study area is located near...

  4. 2013 Oregon Department of Geology and Mineral Industries (DOGAMI) Oregon Lidar: Big Windy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In July of 2013, lightning strikes ignited three wildfires in southwest Oregon that became known as the Big Windy Complex. The fires were fully contained by the end...

  5. Atmospheric Disturbance Environment Definition

    Science.gov (United States)

    Tank, William G.

    1994-01-01

    Traditionally, the application of atmospheric disturbance data to airplane design problems has been the domain of the structures engineer. The primary concern in this case is the design of structural components sufficient to handle transient loads induced by the most severe atmospheric "gusts" that might be encountered. The concern has resulted in a considerable body of high altitude gust acceleration data obtained with VGH recorders (airplane velocity, V, vertical acceleration, G, altitude, H) on high-flying airplanes like the U-2 (Ehernberger and Love, 1975). However, the propulsion system designer is less concerned with the accelerations of the airplane than he is with the airflow entering the system's inlet. When the airplane encounters atmospheric turbulence it responds with transient fluctuations in pitch, yaw, and roll angles. These transients, together with fluctuations in the free-stream temperature and pressure will disrupt the total pressure, temperature, Mach number and angularity of the inlet flow. For the mixed compression inlet, the result is a disturbed throat Mach number and/or shock position, and in extreme cases an inlet unstart can occur (cf. Section 2.1). Interest in the effects of inlet unstart on the vehicle dynamics of large, supersonic airplanes is not new. Results published by NASA in 1962 of wind tunnel studies of the problem were used in support of the United States Supersonic Transport program (SST) (White, at aI, 1963). Such studies continued into the late 1970's. However, in spite of such interest, there never was developed an atmospheric disturbance database for inlet unstart analysis to compare with that available for the structures load analysis. Missing were data for the free-stream temperature and pressure disturbances that also contribute to the unStart problem.

  6. The bibliometrics of atmospheric environment

    Science.gov (United States)

    Brimblecombe, Peter; Grossi, Carlota M.

    Bibliometric analysis is an important tool in the management of a journal. SCOPUS output is used to assess the increase in the quantity of material in Atmospheric Environment and stylistic changes in the way authors choose words and punctuation in titles and assemble their reference lists. Citation analysis is used to consider the impact factor of the journal, but perhaps more importantly the way in which it reflects the importance authors give to papers published in Atmospheric Environment. The impact factor of Atmospheric Environment (2.549 for 2007) from the Journal Citation Reports suggests it performs well within the atmospheric sciences, but it conceals the long term value authors place on papers appearing in the journal. Reference lists show that a fifth come through citing papers more than a decade old.

  7. Atmospheric pollution in our environment

    International Nuclear Information System (INIS)

    Tanvir, G.

    1986-01-01

    Air pollution is associated with all the activities of humans. It is becoming a serious problem in coming years so it is relevant to find out how seriously our atmosphere is being polluted and how this pollution affects human and plant life in our environment. Not only the human activities are the source of our pollution but nature causes more pollution. Air pollution that is due to the pressure of foreign substances in air, effects the quality and concentration of air substances. It is not only injurious to property, but also to vegetation and animal life. Air pollution is one of our most serious environmental problems. The sources vary from smoke-stacks and automobiles to noise and foreon containing aerosols. (orig./A.B.)

  8. Two Rebt Therapists and One Client: Windy Dryden Transcript

    OpenAIRE

    Dryden, Windy

    2010-01-01

    In the summer of 1994, two of the most published authors in the field of Rational Emotive Behavior Therapy (REBT), Albert Ellis and Windy Dryden, each saw the same client. The transcript of Windy Dryden is presented with slight modifications to protect the confidentiality of the client and those in the client’s life.

  9. The Electrostatic Environments of Mars: Atmospheric Discharges

    Science.gov (United States)

    Calle, Carlos I.; Mackey, Paul J.; Johansen, Michael R.; Hogue, Michael D.; Phillips, James, III; Cox, Rachel E.

    2016-01-01

    The electrostatic environment on Mars is controlled by its ever present atmospheric dust. Dust devils and dust storms tribocharge this dust. Theoretical studies predict that lightning and/or glow discharges should be present on Mars, but none have been directly observed. Experiments are planned to shed light on this issue.

  10. The Radiation Environment of Exoplanet Atmospheres

    Directory of Open Access Journals (Sweden)

    Jeffrey L. Linsky

    2014-10-01

    Full Text Available Exoplanets are born and evolve in the radiation and particle environment created by their host star. The host star’s optical and infrared radiation heats the exoplanet’s lower atmosphere and surface, while the ultraviolet, extreme ultraviolet and X-radiation control the photochemistry and mass loss from the exoplanet’s upper atmosphere. Stellar radiation, especially at the shorter wavelengths, changes dramatically as a host star evolves leading to changes in the planet’s atmosphere and habitability. This paper reviews the present state of our knowledge concerning the time-dependent radiation emitted by stars with convective zones, that is stars with spectral types F, G, K, and M, which comprise nearly all of the host stars of detected exoplanets.

  11. White dwarf atmospheres and circumstellar environments

    CERN Document Server

    Hoard, Donald W

    2012-01-01

    Written by selected astronomers at the forefront of their fields, this timely and novel book compiles the latest results from research on white dwarf stars, complementing existing literature by focusing on fascinating new developments in our understanding of the atmospheric and circumstellar environments of these stellar remnants. Complete with a thorough refresher on the observational characteristics and physical basis for white dwarf classification, this is a must-have resource for researchers interested in the late stages of stellar evolution, circumstellar dust and nebulae, and the future

  12. Virtual Exploitation Environment Demonstration for Atmospheric Missions

    Science.gov (United States)

    Natali, Stefano; Mantovani, Simone; Hirtl, Marcus; Santillan, Daniel; Triebnig, Gerhard; Fehr, Thorsten; Lopes, Cristiano

    2017-04-01

    -operational environment, the "Virtual Exploitation Environment Demonstration for Atmospheric Missions" (VEEDAM) aims at maintaining, running and evolving the platform, demonstrating e.g. the possibility to perform massive processing over heterogeneous data sources. This work presents the VEEDAM concepts, provides pre-operational examples, stressing on the interoperability achievable exposing standardized data access and processing services (e.g. making accessible data and processing resources from different VREs). [1] TAMP platform landing page http://vtpip.zamg.ac.at/ [2] TAMP introductory video https://www.youtube.com/watch?v=xWiy8h1oXQY

  13. 76 FR 74074 - Final Environmental Impact Statement for the Windy Gap Firming Project, Colorado

    Science.gov (United States)

    2011-11-30

    ... deliver Windy Gap water to Colorado's Front Range community participants in all years. The purpose of the... to 2005, Windy Gap diverted an average annual 11,080 AF of water per year. However, demands among the... Windy Gap Firming Project, Colorado AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of...

  14. Single event phenomena in atmospheric neutron environments

    International Nuclear Information System (INIS)

    Gossett, C.A.; Hughlock, B.W.; Katoozi, M.; LaRue, G.S.; Wender, S.A.

    1993-01-01

    As integrated circuit technology achieves higher density through smaller feature sizes and as the airplane manufacturing industry integrates more sophisticated electronic components into the design of new aircraft, it has become increasingly important to evaluate the contribution of single event effects, primarily Single Event Upset (SEU), to the safety and reliability of commercial aircraft. In contrast to the effects of radiation on electronic systems in space applications for which protons and heavy ions are of major concern, in commercial aircraft applications the interactions of high energy neutrons are the dominant cause of single event effects. These high energy neutrons are produced by the interaction of solar and galactic cosmic rays, principally protons and heavy ions, in the upper atmosphere. This paper will describe direct experimental measurements of neutron-induced Single Event Effect (SEE) rates in commercial high density static random access memories in a neutron environment characteristic of that at commercial airplane altitudes. The first experimental measurements testing current models for neutron-silicon burst generation rates will be presented, as well as measurements of charge collection in silicon test structures as a function of neutron energy. These are the first laboratory SEE and charge collection measurements using a particle beam having a continuum energy spectrum and with a shape nearly identical to that observed during flight

  15. The changing winds of atmospheric environment policy

    International Nuclear Information System (INIS)

    Murray, Frank

    2013-01-01

    Highlights: ► Changes in atmosphere policies over several decades are analysed. ► Direct regulation is less effective and been complemented by other instruments. ► Policy approaches are more complex and integrated and the scale of the issues has evolved. ► The role of stakeholders has grown and the corporate sector has assumed increased responsibility. ► Governance arrangements have become more complex, multilevel and polycentric. -- Abstract: Atmospheric environmental policies have changed considerably over the last several decades. Clearly the relative importance of the various issues has changed over half a century, for example from smoke, sulphur dioxide and photochemical smog being the top priorities to greenhouse gases being the major priority. The traditional policy instrument to control emissions to the atmosphere has been command and control regulation. In many countries this was successful in reducing emissions from point sources, the first generation issues, and to a lesser extent, emissions from mobile and area sources, the second generation issues, although challenges remain in many jurisdictions. However once the simpler, easier, cheaper and obvious targets had been at least partially controlled this form of regulation became less effective. It has been complemented by other instruments including economic instruments, self-regulation, voluntarism and information instruments to address more complex issues including climate change, a third generation issue. Policy approaches to atmospheric environmental issues have become more complex. Policies that directly focus on atmospheric issues have been partially replaced by more integrated approaches that consider multimedia (water, land, etc.) and sustainability issues. Pressures from stakeholders for inclusion, greater transparency and better communication have grown and non-government stakeholders have become increasingly important participants in governance. The scale of the issues has evolved

  16. Response to subcommittee on environment and atmosphere

    International Nuclear Information System (INIS)

    MacCracken, M.C.

    1975-10-01

    The potential effects of chronic release of pollutants on climatic changes are discussed with regard to dose-response characteristics, ambiguities in prediction of climatic effects, ambiguities in measuring climatic effects, research approaches, and approaches to standard setting. A table is presented to show potential atmospheric effects of the following pollutants: CO 2 from fossil fuels, fluorocarbons, nitrogen oxides, 85 K from nuclear power plants, sulfur compounds, dusts, heat and water releases from energy generation processes, and oceanic oil slicks

  17. Harsh Environment Gas Sensor Array for Venus Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering and the Ohio State University propose to develop a harsh environment tolerant gas sensor array for atmospheric analysis in future Venus missions....

  18. Fixing atmospheric CO2 by environment adaptive sorbent and renewable energy

    Science.gov (United States)

    Wang, T.; Liu, J.; Ge, K.; Fang, M.

    2014-12-01

    Fixing atmospheric CO2, followed by geologic storage in remote areas is considered an environmentally secure approach to climate mitigation. A moisture swing sorbent was investigated in the laboratory for CO2 capture at a remote area with humid and windy conditions. The energy requirement of moisture swing absorption could be greatly reduced compared to that of traditional high-temperature thermal swing, by assuming that the sorbent can be naturally dried and regenerated at ambient conditions. However, for currently developed moisture swing materials, the CO2 capacity would drop significantly at high relative humidity. The CO2 capture amount can be reduced by the poor thermodynamics and kinetics at high relative humidity or low temperature. Similar challenges also exist for thermal or vacuum swing sorbents. Developing sorbent materials which adapt to specific environments, such as high humidity or low temperature, can ensure sufficient capture capacity on the one hand, and realize better economics on the other hand (Figure 1) .An environment adaptive sorbent should have the abilities of tunable capacity and fast kinetics at extreme conditions, such as high humidity or low temperature. In this presentation, the possibility of tuning CO2 absorption capacity of a polymerized ionic liquid material is discussed. The energy requirement evaluation shows that tuning the CO2 binding energy of sorbent, rather than increasing the temperature or reducing the humidity of air, could be much more economic. By determining whether the absorption process is controlled by physical diffusion controlled or chemical reaction, an effective approach to fast kinetics at extreme conditions is proposed. A shrinking core model for mass transfer kinetics is modified to cope with the relatively poor kinetics of air capture. For the studied sample which has a heterogeneous structure, the kinetic analysis indicates a preference of sorbent particle size optimization, rather than support layer

  19. 1988 activity report of the Atmospheric and Aquatic Environment Department

    International Nuclear Information System (INIS)

    Mery, P.

    1988-01-01

    The 1988 activity report of the Atmospheric and Aquatic Environment Department of EDF (Electricity of France) is presented. The activities are focused on the following subjects: development studies in the fields of hydraulic, hydrobiology, meteorology and atmospheric polluants physico-chemistry; application studies involving data analysis from operating or under development power systems; actions concerning cooperation with the Minister of the Environment and the Minister of the Industry. The investigations related to water and atmosphere are reported, as well as congress communications and papers [fr

  20. Vulnerability assessment of atmospheric environment driven by human impacts.

    Science.gov (United States)

    Zhang, Yang; Shen, Jing; Ding, Feng; Li, Yu; He, Li

    2016-11-15

    Atmospheric environment quality worsening is a substantial threat to public health worldwide, and in many places, air pollution due to the intensification of the human activity is increasing dramatically. However, no studies have been investigated the integration of vulnerability assessment and atmospheric environment driven by human impacts. The objective of this study was to identify and prioritize the undesirable environmental changes as an early warning system for environment managers and decision makers in term of human, atmospheric environment, and social economic elements. We conduct a vulnerability assessment method of atmospheric environment associated with human impact, this method integrates spatial context of Geographic Information System (GIS) tool, multi-criteria decision analysis (MCDA) method, ordered weighted averaging (OWA) operators under the Exposure-Sensitivity- Adaptive Capacity (ESA) framework. Decision makers can find out relevant vulnerability assessment results with different vulnerable attitudes. In the Beijing-Tianjin-Hebei (BTH) region, China, we further applied this developed method and proved it to be reliable and consistent with the China Environmental Status Bulletin. Results indicate that the vulnerability of atmospheric environment in the BTH region is not optimistic, and environment managers should do more about air pollution. Thus, the most appropriate strategic decision and development program of city or state can be picked out assisting by the vulnerable results. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Aviation Safety Program Atmospheric Environment Safety Technologies (AEST) Project

    Science.gov (United States)

    Colantonio, Ron

    2011-01-01

    Engine Icing: Characterization and Simulation Capability: Develop knowledge bases, analysis methods, and simulation tools needed to address the problem of engine icing; in particular, ice-crystal icing Airframe Icing Simulation and Engineering Tool Capability: Develop and demonstrate 3-D capability to simulate and model airframe ice accretion and related aerodynamic performance degradation for current and future aircraft configurations in an expanded icing environment that includes freezing drizzle/rain Atmospheric Hazard Sensing and Mitigation Technology Capability: Improve and expand remote sensing and mitigation of hazardous atmospheric environments and phenomena

  2. Atmospheric environment responses to fossil energy and renewable energy alternatives

    International Nuclear Information System (INIS)

    Sen, Z.

    1998-01-01

    Fossil energy consumption and the atmospheric environmental problems are closely related leading together with various recent weather phenomena such as the climate change, global warming, greenhouse effect and atmospheric pollution. Accumulation of harmful emissions from the fossil fuels such as coal and oil causes increase in carbon dioxide levels in the atmosphere which shield the long wave solar irradiation from the earth to outer space and consequently the temperature within the atmospheric layer increases giving rise to expected global warming and many long term undesirable disastrous events such as droughts, floods, the sea level rises as a result of polar ice melting, shifts of tropical belts towards the polar regions, undulating of low lying lands in addition to many other social effects. In order to reduce these undesirable effects, the atmosphere as a common property of all the world, must be protected jointly by all the countries. Hence, each country must contribute her share by reducing the use of fossil fuels with the replacement of environment friendly renewable energy resources such as solar, solar-hydrogen, wind and hydropower. In order to know the right for a country to defend herself for future accusations of atmospheric environmental pollution she must know and set up policies as her energy consumption levels and renewable energy potentials. This paper presents general account of fossil fuel usage consequences in the atmosphere. 15 refs

  3. Measurement of atmospheric MTF in a littoral environment

    CSIR Research Space (South Africa)

    Griffith, DJ

    2008-09-01

    Full Text Available of atmospheric turbulence and specifically the atmospheric MTF over short to medium range in the littoral environment. There were two main aspects of interest. The first aspect was that of accumulating data to get an idea of the severity and variability... was compromised on a few occasions. Signal flux was very low during the heavier rain showers. On imagery from some of the telescopes, the lighthouse lamp had to be masked out on the images acquired at night. A large boat obscured the sources on one occasion...

  4. Subterranean karst environments as a global sink for atmospheric methane

    Science.gov (United States)

    Webster, Kevin D.; Drobniak, Agnieszka; Etiope, Giuseppe; Mastalerz, Maria; Sauer, Peter E.; Schimmelmann, Arndt

    2018-03-01

    The air in subterranean karst cavities is often depleted in methane (CH4) relative to the atmosphere. Karst is considered a potential sink for the atmospheric greenhouse gas CH4 because its subsurface drainage networks and solution-enlarged fractures facilitate atmospheric exchange. Karst landscapes cover about 14% of earth's continental surface, but observations of CH4 concentrations in cave air are limited to localized studies in Gibraltar, Spain, Indiana (USA), Vietnam, Australia, and by incomplete isotopic data. To test if karst is acting as a global CH4 sink, we measured the CH4 concentrations, δ13CCH4, and δ2HCH4 values of cave air from 33 caves in the USA and three caves in New Zealand. We also measured CO2 concentrations, δ13CCO2, and radon (Rn) concentrations to support CH4 data interpretation by assessing cave air residence times and mixing processes. Among these caves, 35 exhibited subatmospheric CH4 concentrations in at least one location compared to their local atmospheric backgrounds. CH4 concentrations, δ13CCH4, and δ2HCH4 values suggest that microbial methanotrophy within caves is the primary CH4 consumption mechanism. Only 5 locations from 3 caves showed elevated CH4 concentrations compared to the atmospheric background and could be ascribed to local CH4 sources from sewage and outgassing swamp water. Several associated δ13CCH4 and δ2HCH4 values point to carbonate reduction and acetate fermentation as biochemical pathways of limited methanogenesis in karst environments and suggest that these pathways occur in the environment over large spatial scales. Our data show that karst environments function as a global CH4 sink.

  5. Results from the Lunar Atmosphere and Dust Environment Explorer (LADEE)

    Science.gov (United States)

    Elphic, Richard; Stubbs, Timothy

    On 6 September, 2013, a near-perfect launch of the first Minotaur V rocket successfully carried NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) into a high-eccentricity geocentric orbit. After 30 days of phasing, LADEE arrived at the Moon on 6 October, 2013. LADEE’s science objectives are twofold: (1) Determine the composition of the lunar atmosphere, investigate processes controlling its distribution and variability, including sources, sinks, and surface interactions; (2) Characterize the lunar exospheric dust environment, measure its spatial and temporal variability, and effects on the lunar atmosphere, if any. After a successful commissioning phase, the three science instruments have made systematic observations of the lunar dust and exospheric environment. These include initial observations of argon, neon and helium exospheres, and their diurnal variations; the lunar micrometeoroid impact ejecta cloud and its variations; spatial and temporal variations of the sodium and potassium exospheres; and the search for sunlight extinction caused by dust. LADEE also made observations of the effects of the Chang’e 3 landing on 14 December 2013, and the Geminid meteor shower.

  6. Space Suit Environment Testing of the Orion Atmosphere Revitalization Technology

    Science.gov (United States)

    Button, Amy B.; Sweterlitsch, Jeffrey J.; Cox, Marlon R.

    2010-01-01

    An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). In three previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of this technology. That testing was performed in a sea-level pressure environment with both simulated and real human metabolic loads, and in both open and closed-loop configurations. The Orion ARS is designed to also support space-suited operations in a depressurized cabin, so the next step in developmental testing at JSC was to test the ARS technology in a typical closed space suit-loop environment with low-pressure oxygen inside the process loop and vacuum outside the loop. This was the first instance of low-pressure, high-oxygen, closed-loop testing of the Orion ARS technology, and it was conducted with simulated human metabolic loads in March 2009. The test investigated pressure drops and flow balancing through two different styles of prototype suit umbilical connectors. General swing-bed performance was tested with both umbilical configurations, as well as with a short jumper line installed in place of the umbilicals. Other interesting results include observations on the thermal effects of swing-bed operation in a vacuum environment and a recommendation of cycle time to maintain acceptable suit atmospheric CO2 and moisture levels.

  7. Late Holocene dune mobilizations in the northwestern Negev dunefield, Israel: A response to combined anthropogenic activity and short-term intensified windiness

    Science.gov (United States)

    Roskin, Joel; Katra, Itzhak; Blumberg, Dan G.

    2013-04-01

    dune chronostratigraphy. Because they were short lived, the dune mobilization events, corresponding windiness, and probable dustiness which were examined affected the northern Negev landscape differentially. However, they cannot be proved to have affected the environment sufficiently to influence the decline of the late Byzantine and Early Islam agricultural establishment. This study demonstrates the sensitivity of dunes in arid and semi-arid regions to a combination of local and short-term fluctuations in windiness at times of widespread grazing (anthropogenic activity). The results remind us that in similar future scenarios, sand mobilization may be similarly retriggered to varying degrees.

  8. Time evolution of artificial plasma cloud in atmospheric environment

    International Nuclear Information System (INIS)

    Lu Qiming; Yang Weihong; Liu Wandong

    2004-01-01

    By analyzing the time evolution of artificial plasma cloud in the high altitude of atmospheric environment, the authors found that there are two zones, an exponential attenuation zone and a linearly attenuating zone, existing in the spatial distribution of electron density of the artificial plasma clouds. The plasma generator's particle flux density only contributes to the exponential attenuation zone, and has no effect on the linear attenuation zone. The average electron density in the linear attenuation zone is about 10 -5 of neutral particle density, and can diffuse over a wider area. The conclusion will supply some valuable references to the research of electromagnetic wave and artificial plasma interaction, the plasma invisibleness research of missile and special aerocraft, and the design of artificial plasma source. (authors)

  9. [Determination of volatile organic compounds in atmospheric environment].

    Science.gov (United States)

    Chen, H W; Li, G K; Li, H; Zhang, Z X; Wang, B G; Li, T; Luo, H K

    2001-11-01

    It is well known that volatile organic compounds (VOCs) are the main photochemical pollutants and ozone precursors of the photochemical smog. Investigation of photochemical pollution in the ambient air must focus on VOCs, but the concentration of VOCs in ambient air is in a very low level (10(-9)-10(-12), volume fraction), so there are difficulties in the determination of VOCs. In this work, based on the TO14A and TO15 methods recommended by the Environmental Protection Agency of United States, an improved method for the determination of fifty-six VOCs, mainly O3 precursors, in atmospheric environment was developed. Operating conditions of VOCs preconcentrator, gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were optimized. Air sample was first frozen by liquid nitrogen, and then H2O and CO2 were eliminated in the VOCs preconcentrator. The preconcentrated VOCs sample was injected to GC and detected by MS or hydrogen flame ionization detector (FID). The C2-C10 hydrocarbons were separated effectively in capillary columns under the high concentration of CO2. The detection limits were 0.1 microgram.m-3 and the relative standard deviations were in the range from 2.57% to 9.82%. This method has been used for the determination of VOCs in real samples. The results were satisfactory.

  10. The Impact of Meteoroid Streams on the Lunar Atmosphere and Dust Environment During the LADEE Mission

    Science.gov (United States)

    Stubbs, T. J.; Glenar, D. A.; Wang, Y.; Hermalyn, B.; Sarantos, M.; Colaprete, A.; Elphic, R. C.

    2015-01-01

    The scientific objectives of the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission are: (1) determine the composition of the lunar atmosphere, investigate processes controlling distribution and variability - sources, sinks, and surface interactions; and (2) characterize the lunar exospheric dust environment, measure spatial and temporal variability, and influences on the lunar atmosphere. Impacts on the lunar surface from meteoroid streams encountered by the Earth-Moon system are anticipated to result in enhancements in the both the lunar atmosphere and dust environment. Here we describe the annual meteoroid streams expected to be incident at the Moon during the LADEE mission, and their anticipated effects on the lunar environment.

  11. Mercury in the atmospheric and coastal environments of Mexico.

    Science.gov (United States)

    Ruelas-Inzunza, Jorge; Delgado-Alvarez, Carolina; Frías-Espericueta, Martín; Páez-Osuna, Federico

    2013-01-01

    In Mexico, published studies relating to the occurrence of Hg in the environment are limited. Among the main sources of Hg in Mexico are mining and refining of Auand Hg, chloralkali plants, Cu smelting, residential combustion of wood, carbo electric plants, and oil refineries. Hg levels are highly variable in the atmospheric compartment because of the atmospheric dynamics and ongoing metal exchange with the terrestrial surface. In atmospheric studies, Hg levels are usually reported as total gaseous Hg (TGM). In Mexico, TGM values ranged from 1.32 ng m-3 in Hidalgo state (a rural agricultural area) to 71.82 ng m-3 in Zacatecas state (an area where brick manufacturers use mining wastes as a raw material).Published information on mercury levels in the coastal environment comprise 21 studies, representing 21 areas, in which sediments constituted the substrate that was analyzed for Hg. In addition, water samples were analyzed for Hg in nine studies.Few studies exist on Hg levels in the Caribbean and in the southwest of the country where tourism is rapidly increasing. Hence, there is a need for establishing baseline levels of mercury in these increasingly visited areas. In regions where studies have been undertaken, Hg levels in sediments were highly variable. Variations in Hg sediment levels mainly result from geological factors and the varying degree of anthropogenic impacts in the studied areas. In areas that still have pristine or nearly pristine environments (e.g., coast, Baja California, Todos Santos Bay, and La Paz lagoon), sediment Hg levels ranged from waste releases and exhaust from the thermo electric plants. The levels of Hg in water reveal a moderate to elevated contamination of some Mexican coastal sites. In Urias lagoon (NW Mexico), moderate to high levels were found in the dissolved and suspended fraction, and these are related to shipping, the fishing industry, domestic effluents, and the presence of a thermoelectric plant. In Coatzacoalcos (SE Mexico

  12. Heated-Atmosphere Airship for the Titan Environment: Thermal Analysis

    Science.gov (United States)

    Heller, R. S.; Landis, G. A.; Hepp, A. F.; Colozza, A. J.

    2012-01-01

    Future exploration of Saturn's moon Titan can be carried out by airships. Several lighter-than-atmosphere gas airships and passive drifting heated-atmosphere balloon designs have been studied, but a heated-atmosphere airship could combine the best characteristics of both. This work analyses the thermal design of such a heated-atmosphere vehicle, and compares the result with a lighter-than-atmosphere (hydrogen) airship design. A design tool was created to enable iteration through different design parameters of a heated-atmosphere airship (diameter, number of layers, and insulating gas pocket thicknesses) and evaluate the feasibility of the resulting airship. A baseline heated-atmosphere airship was designed to have a diameter of 6 m (outer diameter of 6.2 m), three-layers of material, and an insulating gas pocket thickness of 0.05 m between each layer. The heated-atmosphere airship has a mass of 161.9 kg. A similar mission making use of a hydrogen-filled airship would require a diameter of 4.3 m and a mass of about 200 kg. For a long-duration mission, the heated-atmosphere airship appears better suited. However, for a mission lifetime under 180 days, the less complex hydrogen airship would likely be a better option.

  13. Flight Load Assessment for Light Aircraft Landing Trajectories in Windy Atmosphere and Near Wind Farms

    Directory of Open Access Journals (Sweden)

    Carmine Varriale

    2018-04-01

    Full Text Available This work focuses on the wake encounter problem occurring when a light, or very light, aircraft flies through or nearby a wind turbine wake. The dependency of the aircraft normal load factor on the distance from the turbine rotor in various flight and environmental conditions is quantified. For this research, a framework of software applications has been developed for generating and controlling a population of flight simulation scenarios in presence of assigned wind and turbulence fields. The JSBSim flight dynamics model makes use of several autopilot systems for simulating a realistic pilot behavior during navigation. The wind distribution, calculated with OpenFOAM, is a separate input for the dynamic model and is considered frozen during each flight simulation. The aircraft normal load factor during wake encounters is monitored at different distances from the rotor, aircraft speeds, rates of descent and crossing angles. Based on these figures, some preliminary guidelines and recommendations on safe encounter distances are provided for general aviation aircraft, with considerations on pilot comfort and flight safety. These are needed, for instance, when an accident risk assessment study is required for flight in proximity of aeolic parks. A link to the GitHub code repository is provided.

  14. An atmospheric vulnerability assessment framework for environment management and protection based on CAMx.

    Science.gov (United States)

    Zhang, Yang; Shen, Jing; Li, Yu

    2018-02-01

    This paper presents an atmospheric vulnerability assessment framework based on CAMx that should be helpful to assess potential impacts of changes in human, atmospheric environment, and social economic elements of atmospheric vulnerability. It is also a useful and effective tool that can provide policy-guidance for environmental protection and management to reduce the atmospheric vulnerability. The developed framework was applied to evaluate the atmospheric environment vulnerability of 13 cities in the Beijing-Tianjin-Hebei (BTH) region for verification. The results indicated that regional disparity of the atmospheric vulnerability existed in the study site. More specifically, the central and southern regions show more atmospheric environment vulnerability than the northern regions. The impact factors of atmospheric environment vulnerability in the BTH region mainly derived from increasing population press, frequently unfavorable meteorological conditions, extensive economic growth of secondary industry, increased environmental pollution, and accelerating population aging. The framework shown in this paper is an interpretative and heuristic tool for a better understanding of atmospheric vulnerability. This framework can also be replicated at different spatial and temporal scales using context-specific datasets to straightly support environmental managers with decision-making. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Record of Decision for the Electrical Interconnection of the Windy Point Wind Energy Project.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    2006-11-01

    The Bonneville Power Administration (BPA) has decided to offer contract terms for interconnection of 250 megawatts (MW) of power to be generated by the proposed Windy Point Wind Energy Project (Wind Project) into the Federal Columbia River Transmission System (FCRTS). Windy Point Partners, LLC (WPP) propose to construct and operate the proposed Wind Project and has requested interconnection to the FCRTS. The Wind Project will be interconnected at BPA's Rock Creek Substation, which is under construction in Klickitat County, Washington. The Rock Creek Substation will provide transmission access for the Wind Project to BPA's Wautoma-John Day No.1 500-kilovolt (kV) transmission line. BPA's decision to offer terms to interconnect the Wind Project is consistent with BPA's Business Plan Final Environmental Impact Statement (BP EIS) (DOE/EIS-0183, June 1995), and the Business Plan Record of Decision (BP ROD, August 15, 1995). This decision thus is tiered to the BP ROD.

  16. Harsh Environment Gas Sensor Array for Venus Atmospheric Measurements, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering and the Ohio State University propose to develop a harsh environment tolerant gas sensor array for atmospheric analysis in future Venus missions....

  17. Inferring atmospheric weather conditions in volcanic environments using infrasound

    Science.gov (United States)

    Ortiz, H. D.; Johnson, J. B.; Ruiz, M. C.

    2015-12-01

    We use infrasound produced by Tungurahua Volcano (Ecuador) to infer local time-varying atmospheric conditions, which can be used to improve gas flux measurements and tephra dispersal modeling. Physical properties of the atmosphere, including wind and temperature (which controls adiabatic sound speed), can be quantified by studying the travel times of acoustic waves produced during volcanic activity. The travel times between Tungurahua's vent and five infrasound stations located in a network configuration over an area of 90 km2 were used in this study. We are able to quantify the arrival time differences of acoustic waves for ten unique station pairs and use this information to model the average speed of sound between source and receiver. To identify what parameters best fit the observed arrival times, we perform a grid search for a homogeneous two-dimensional wind velocity as well as for air temperature. Due to travel time dependence on the specific path taken by waves, we account for topography using a 5 meter resolution digital elevation model of Tungurahua. To investigate the time-varying atmospheric structure we use data recorded at Tungurahua volcano, during a strombolian eruptive phase in August 2012, however the methodology can be applied to continuous network infrasound data collected since July 2006 as part of the Japanese-Ecuadorian Cooperation Project: "Enhancement of the Volcano Monitoring Capacity in Ecuador". We propose that the computation of wind velocities will help to improve gas flux measurements that are based on remote sensing techniques like Differential Optical Absorption Spectroscopy (DOAS), resulting in better estimates of sulfur fluxes that can then be related to magma fluxing into the volcanic system. Further, wind field quantification close to the volcano can improve numerical models that are used to forecast tephra deposits, thereby helping to mitigate their effect on inhabitants, infrastructure, livestock, and crops.

  18. Atmospheric environment problems in Nigeria—An overview

    Science.gov (United States)

    Akeredolu, Funso

    The air pollution sources in Nigeria are discussed. Particulate matter constitutes the major atmospheric pollution problem. Both anthropogenic and non-anthropogenic sources of paniculate matter were found to be important. The Harmattan dust haze constitutes the largest anthropogenic source of particulate matter. Severe visibility reduction and increased incidence of respiratory and chest congestion complaints are recorded during the Harmattan season. Dust remobilization resulting from vehicular traffic on unpaved as well as on unswept paved roads and from fugitive emissions from open surfaces and biomass burning are the major non-anthropogenic sources of particulate matter. Industries generate and emit particulate as well as gaseous pollutants which have manifested significant negative impact at local levels. Combustion-derived pollution was seen to be increasing. The annual atmospheric particle loading for the country was estimated as 2.75 × 10 9 kg with the following source contributions: bush burning (31.7%), fugitive dust from roads (29.1%), fuel wood burning (21.3%), Harmattan dust (13.8%), solid waste incineration (2.1%), stationary sources (1.6%), automobile exhaust lead (0.2%) and gas flares (0.1%). Very little data exist on the ambient air quality of Nigerian cities. The few synoptic data available indicate ambient concentrations of CO and SO 2 exceeding WHO short-term limits for those gases. The results of lead level measurements in biotic species and in road surface dusts at several locations were found to be high. Important meteorological peculiarities of the atmosphere over Nigerian urban and industrial cities were considered. The air pollution potentials of these cities were then discussed.

  19. The lunar atmosphere and dust environment explorer mission (LADEE)

    CERN Document Server

    Russell, Christopher

    2015-01-01

    This volume contains five articles describing the mission and its instruments.  The first paper, by the project scientist Richard C. Elphic and his colleagues, describes the mission objectives, the launch vehicle, spacecraft and the mission itself.  This is followed by a description of LADEE’s Neutral Mass Spectrometer by Paul Mahaffy and company.  This paper describes the investigation that directly targets the lunar exosphere, which can also be explored optically in the ultraviolet.  In the following article Anthony Colaprete describes LADEE’s Ultraviolet and Visible Spectrometer that operated from 230 nm to 810 nm scanning the atmosphere just above the surface.  Not only is there atmosphere but there is also dust that putatively can be levitated above the surface, possibly by electric fields on the Moon’s surface.  Mihaly Horanyi leads this investigation, called the Lunar Dust Experiment, aimed at understanding the purported observations of levitated dust.  This experiment was also very succes...

  20. Multi-scale atmospheric environment modelling for urban areas

    Directory of Open Access Journals (Sweden)

    A. A. Baklanov

    2009-04-01

    Full Text Available Modern supercomputers allow realising multi-scale systems for assessment and forecasting of urban meteorology, air pollution and emergency preparedness and considering nesting with obstacle-resolved models. A multi-scale modelling system with downscaling from regional to city-scale with the Environment – HIgh Resolution Limited Area Model (Enviro-HIRLAM and to micro-scale with the obstacle-resolved Micro-scale Model for Urban Environment (M2UE is suggested and demonstrated. The M2UE validation results versus the Mock Urban Setting Trial (MUST experiment indicate satisfactory quality of the model. Necessary conditions for the choice of nested models, building descriptions, areas and resolutions of nested models are analysed. Two-way nesting (up- and down-scaling, when scale effects both directions (from the meso-scale on the micro-scale and from the micro-scale on the meso-scale, is also discussed.

  1. Atmospheric Environment Vulnerability Cause Analysis for the Beijing-Tianjin-Hebei Metropolitan Region.

    Science.gov (United States)

    Zhang, Yang; Shen, Jing; Li, Yu

    2018-01-13

    Assessing and quantifying atmospheric vulnerability is a key issue in urban environmental protection and management. This paper integrated the Analytical hierarchy process (AHP), fuzzy synthesis evaluation and Geographic Information System (GIS) spatial analysis into an Exposure-Sensitivity-Adaptive capacity (ESA) framework to quantitatively assess atmospheric environment vulnerability in the Beijing-Tianjin-Hebei (BTH) region with spatial and temporal comparisons. The elaboration of the relationships between atmospheric environment vulnerability and indices of exposure, sensitivity, and adaptive capacity supports enable analysis of the atmospheric environment vulnerability. Our findings indicate that the atmospheric environment vulnerability of 13 cities in the BTH region exhibits obvious spatial heterogeneity, which is caused by regional diversity in exposure, sensitivity, and adaptive capacity indices. The results of atmospheric environment vulnerability assessment and the cause analysis can provide guidance to pick out key control regions and recognize vulnerable indicators for study sites. The framework developed in this paper can also be replicated at different spatial and temporal scales using context-specific datasets to support environmental management.

  2. Enhanced Hover Control of Quad Tilt Frame UAV under Windy Conditions

    Directory of Open Access Journals (Sweden)

    R. Krishnakumar

    2015-10-01

    Full Text Available A key research subject in the area of unmanned aerial vehicles (UAVs is how to make them autonomous. Towards this goal, the most vital step is stabilizing the attitude of the vehicles. This paper presents the design of an autonomous control system for a hybrid UAV to enable it to carry out a stable hovering mission under external wind disturbances. The hovering capability of the hybrid UAV under windy conditions is analysed with computational fluid dynamics (CFD and a control law is designed to stabilize the craft in the hovering position. The proposed hovering controller is verified with simulations and experiments. Finally, the flight control system is installed in a small prototype and a full transition flight test, including vertical take-off, transition from vertical flight to cruise, cruise, transition cruise to vertical mode and hover landing, is successfully accomplished.

  3. Thoron (220Rn) in the indoor atmospheric environment

    International Nuclear Information System (INIS)

    Ramachandran, T.V.

    2006-01-01

    Naturally occurring background radiation is a topic, which has evoked curiosity and concern between the scientist and layman alike in recent years due to the shift in focus of health effects due to exposure of radiation from acute high level to chronic low level. Many locations around the world have higher levels of natural background radiation due to elevated levels of primordial radio nuclides in the soil and their decay products like radon ( 222 Rn), and thoron ( 220 Rn) in the environment. Of late, technologically enhanced naturally occurring radioactive material has also contributed to the burden of background radiation. It has been estimated that inhalation of 222 Rn, 2 20 Rn and their short lived progenies contribute more than 54% of the total natural background radiation dose received by the general population. In the Indian context, in an earlier national survey, the external gamma radiation dose rates have been more or less well mapped using thermo luminescent dosimeters covering more than 214 locations, which has yielded a national average of 775 mGy/y. Of this, nearly 48.7% contribution of the dose rate is from 40 K and the rest from the uranium (33.6%) and thorium (17.7%) series. A good database pertaining to the country wide levels of uranium, thorium and potassium in geological materials also exists. Thus, there exists a good database on the total external gamma radiation level across the country. Since the contribution from inhalation of 222 Rn, 220 Rn and their short lived progenies contributes more than 54% of the total background radiation dose, it was necessary to supplement the external component with inhalation component. This component is not adequately estimated for the country so far on national level. With this in mind, a national survey has been executed by this center involving a large number of universities and other allied research institutions from different parts of the country for the estimation of inhalation component of the dose

  4. Evaluating the Contributions of Atmospheric Deposition of Carbon and Other Nutrients to Nitrification in Alpine Environments

    Science.gov (United States)

    Oldani, K. M.; Mladenov, N.; Williams, M. W.

    2013-12-01

    The Colorado Front Range of the Rocky Mountains contains undeveloped, barren soils, yet in this environment there is strong evidence for a microbial role in increased nitrogen (N) export. Barren soils in alpine environments are severely carbon-limited, which is the main energy source for microbial activity and sustenance of life. It has been shown that atmospheric deposition can contain high amounts of organic carbon (C). Atmospheric pollutants, dust events, and biological aerosols, such as bacteria, may be important contributors to the atmospheric organic C load. In this stage of the research we evaluated seasonal trends in the chemical composition and optical spectroscopic (fluorescence and UV-vis absorbance) signatures of snow, wet deposition, and dry deposition in an alpine environment at Niwot Ridge in the Rocky Mountains of Colorado to obtain a better understanding of the sources and chemical character of atmospheric deposition. Our results reveal a positive trend between dissolved organic carbon concentrations and calcium, nitrate and sulfate concentrations in wet and dry deposition, which may be derived from such sources as dust and urban air pollution. We also observed the presence of seasonally-variable fluorescent components that may be attributed to fluorescent pigments in bacteria. These results are relevant because atmospheric inputs of carbon and other nutrients may influence nitrification in barren, alpine soils and, ultimately, the export of nitrate to alpine watersheds.

  5. Corrosion Prediction Model of Q235 Steel in Polluted Marine Atmospheric Environment

    Directory of Open Access Journals (Sweden)

    WANG Xu

    2017-04-01

    Full Text Available The corrosion behaviour of Q235 steel in Qingdao and Wanning of China,the two kinds of polluted marine environment were simulated by cyclic immersion test, and the correlation of indoor cyclic immersion test and outdoor marine atmospheric corrosion test of Q235 steel were studied. The corrosion morphologies, corrosion products, corrosion kinetics of Q235 steel were investigated with methods of scanning electron microscopy (SEM, X-ray diffraction (XRD and mass loss. The results reveal that the corrosion morphologies and compositions of corrosion products after cyclic immersion test agree with those after the real atmospheric test. Corrosion prediction model of Q235 steel in two kinds of marine atmospheric environment was built combined with Grey correlation method: T QD=137.002 t 1.093, T WN=102.398 t 0.952.

  6. What do the cited and citing environments reveal about Advances in Atmospheric Physics?

    Science.gov (United States)

    Shi, Aolan; Leydesdorff, Loet

    2011-01-01

    The networking status of journals reflects their academic influence among peer journals. This paper analyzes the cited and citing environments of this journal, Advances in Atmospheric Sciences ( Adv. Atmos. Sci.), using methods from social network analysis. Since its initial publication, Adv. Atmos. Sci. has been actively participating in the international journal environment and international journals are frequently cited in Adv. Atmos. Sci. Particularly, this journal is intensely interrelated with its international peer journals in terms of their similar citing patterns. The international influence of Adv. Atmos. Sci. is comparatively bigger than other Chinese SCI journals in atmospheric sciences as reflected by total cites to Adv. Atmos. Sci. and the total number of international journals citing it. The academic visibility of Adv. Atmos. Sci. is continuing to improve in the international research community as the number of reference citation it receives in its peer journals internationally increases over time.

  7. Demonstrating the Operational Value of Atmospheric Infrared Sounder (AIRS) Profiles in the Pre-Convective Environment

    Science.gov (United States)

    Kozlowski, Danielle; Zavodsky, Bradley; Stano, Geoffrey; Jedlovec, Gary

    2011-01-01

    The Short-term Prediction Research and Transition (SPoRT) is a project to transition those NASA observations and research capabilities to the weather forecasting community to improve the short-term regional forecasts. This poster reviews the work to demonstrate the value to these forecasts of profiles from the Atmospheric Infrared Sounder (AIRS) instrument on board the Aqua satellite with particular assistance in predicting thunderstorm forecasts by the profiles of the pre-convective environment.

  8. Radiation exposure of airline crew members to the atmospheric ionizing radiation environment

    Energy Technology Data Exchange (ETDEWEB)

    De Angelis, G. E-mail: gianni.deangelis@iol.it; Caldora, M.; Santaquilani, M.; Scipione, R.; Verdecchia, A

    2001-06-01

    A study of radiation exposures in the ionizing radiation environment of the atmosphere is currently in progress for the Italian civil aviation flight personnel. After a description of the considered data sources/ the philosophy of the study is presented/ and an overview is given of the data processing with regard to flight routes/ the computational techniques for radiation dose evaluation along the flight paths and for the exposure matrix building/ along with an indication of the results that the study should provide.

  9. Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere

    DEFF Research Database (Denmark)

    Makowska, Malgorzata G.; Kuhn, Luise Theil; Cleemann, Lars Nilausen

    2015-01-01

    High material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible...... with any other technique. This paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 ◦C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging...

  10. Premar-2: a Monte Carlo code for radiative transport simulation in atmospheric environments

    International Nuclear Information System (INIS)

    Cupini, E.

    1999-01-01

    The peculiarities of the PREMAR-2 code, aimed at radiation transport Monte Carlo simulation in atmospheric environments in the infrared-ultraviolet frequency range, are described. With respect to the previously developed PREMAR code, besides plane multilayers, spherical multilayers and finite sequences of vertical layers, each one with its own atmospheric behaviour, are foreseen in the new code, together with the refraction phenomenon, so that long range, highly slanted paths can now be more faithfully taken into account. A zenithal angular dependence of the albedo coefficient has moreover been introduced. Lidar systems, with spatially independent source and telescope, are allowed again to be simulated, and, in this latest version of the code, sensitivity analyses to be performed. According to this last feasibility, consequences on radiation transport of small perturbations in physical components of the atmospheric environment may be analyze and the related effects on searched results estimated. The availability of a library of physical data (reaction coefficients, phase functions and refraction indexes) is required by the code, providing the essential features of the environment of interest needed of the Monte Carlo simulation. Variance reducing techniques have been enhanced in the Premar-2 code, by introducing, for instance, a local forced collision technique, especially apt to be used in Lidar system simulations. Encouraging comparisons between code and experimental results carried out at the Brasimone Centre of ENEA, have so far been obtained, even if further checks of the code are to be performed [it

  11. State estimation for autopilot control of small unmanned aerial vehicles in windy conditions

    Science.gov (United States)

    Poorman, David Paul

    -zero mean error that increases when gyro bias is increased. The second method is shown to not exhibit any steady state error in the tested scenarios that is inherent to its design. The second method can correct for attitude errors that arise from both integration error and gyro bias states, but it suffers from lack of attitude error observability. The attitude errors are shown to be more observable in wind, but increased integration error in wind outweighs the increase in attitude corrections that such increased observability brings, resulting in larger attitude errors in wind. Overall, this work highlights many technical deficiencies of both of these methods of state estimation that could be improved upon in the future to enhance state estimation for small UAVs in windy conditions.

  12. Development of Rotary-Wing UAS for Use in Atmospheric Sensing of Near-Storm Environments

    Science.gov (United States)

    Greene, B. R.; Chilson, P. B.; Salazar-Cerreno, J.; Duthoit, S.; Doyle, B.; Wolf, B.; Segales, A.; Fiebrich, C. A.; Waugh, S.; Fredrickson, S.; Oncley, S.; Tudor, L.; Semmer, S.

    2017-12-01

    The capabilities of small unmanned aircraft systems (sUAS) to make atmospheric observations is rapidly being realized as a means to collect previously unobtainable observations in the lowest part of Earth's atmosphere. However, in order for these systems to provide meaningful kinematic and thermodynamic data, it is imperative to establish an understanding of the strengths and limitations of the sensors and retrieval algorithms implemented in both controlled and realistic conditions. This initial objective is comprised of two experimental stages, the first of which is calibration of thermodynamic sensors against references from the Oklahoma Mesonet and the National Center for Atmospheric Research in order to understand their quasi-ideal response characteristics. Furthermore, efforts have been made to calculate horizontal wind fields using Euler angles derived from the sUAS's autopilot. The second stage is validation of these sensor performances once mounted onto a rotary-wing sUAS by comparing measurements with instrumented towers, radiosondes, and other sUAS. It appears that these measurements are robust provided that instrument packages are mounted such that they receive adequate air flow and proper solar shielding. Moreover, experiments to locate this optimal location have been performed, and involved systematically displacing the sensors and wind probe underneath the rotor wash in an isolated chamber using a linear actuator. Once a platform's atmospheric sensing capabilities are optimized, its utility has been proven in applications from turbulence to providing forecasters with quasi-real time profiles in convective environments deemed by the Storm Prediction Center to be of highest risk for severe thunderstorms. After addressing the development of platforms operated by the University of Oklahoma, results from recent field campaigns, Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUD-MAP) and Environmental Profiling

  13. Synthetic fibers in atmospheric fallout: A source of microplastics in the environment?

    Science.gov (United States)

    Dris, Rachid; Gasperi, Johnny; Saad, Mohamed; Mirande, Cécile; Tassin, Bruno

    2016-03-15

    Sources, pathways and reservoirs of microplastics, plastic particles smaller than 5mm, remain poorly documented in an urban context. While some studies pointed out wastewater treatment plants as a potential pathway of microplastics, none have focused on the atmospheric compartment. In this work, the atmospheric fallout of microplastics was investigated in two different urban and sub-urban sites. Microplastics were collected continuously with a stainless steel funnel. Samples were then filtered and observed with a stereomicroscope. Fibers accounted for almost all the microplastics collected. An atmospheric fallout between 2 and 355 particles/m(2)/day was highlighted. Registered fluxes were systematically higher at the urban than at the sub-urban site. Chemical characterization allowed to estimate at 29% the proportion of these fibers being all synthetic (made with petrochemicals), or a mixture of natural and synthetic material. Extrapolation using weight and volume estimates of the collected fibers, allowed a rough estimation showing that between 3 and 10 tons of fibers are deposited by atmospheric fallout at the scale of the Parisian agglomeration every year (2500 km(2)). These results could serve the scientific community working on the different sources of microplastic in both continental and marine environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Gas-to-particle conversion in the atmospheric environment by radiation-induced and photochemical reactions

    International Nuclear Information System (INIS)

    Vohra, K.G.

    1975-01-01

    During the last few years a fascinating new area of research involving ionizing radiations and photochemistry in gas-to-particle conversion in the atmosphere has been developing at a rapid pace. Two problems of major interest and concern in which this is of paramount importance are: (1) radiation induced and photochemical aerosol formation in the stratosphere and, (2) role of radiations and photochemistry in smog formation. The peak in cosmic ray intensity and significant solar UV flux in the stratosphere lead to complex variety of reactions involving major and trace constituents in this region of the atmosphere, and some of these reactions are of vital importance in aerosol formation. The problem is of great current interest because the pollutant gases from industrial sources and future SST operations entering the stratosphere could increase the aerosol burden in the stratosphere and affect the solar energy input of the troposphere with consequent ecological and climatic changes. On the other hand, in the nuclear era, the atmospheric releases from reactors and processing plants could lead to changes in the cloud nucleation behaviour of the environment and possible increase in smog formation in the areas with significant levels of radiations and conventional pollutants. A review of the earlier work, current status of the problem, and conventional pollutants. A review of the earlier work, current status of the problem, and some recent results of the experiments conducted in the author's laboratory are presented. The possible mechanisms of gas-to-particle conversion in the atmosphere have been explained

  15. Single event upset in static random access memories in atmospheric neutron environments

    CERN Document Server

    Arita, Y; Ogawa, I; Kishimoto, T

    2003-01-01

    Single-event upsets (SEUs) in a 0.4 mu m 4Mbit complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) were investigated in various atmospheric neutron environments at sea level, at an altitude of 2612 m mountain, at an altitude of commercial airplane, and at an underground depth of 476m. Neutron-induced SEUs increase with the increase in altitude. For a device with a borophosphosilicate glass (BPSG) film, SEU rates induced by thermal neutrons increase with the decrease in the cell charge of a memory cell. A thermal neutron-induced SEU is significant in SRAMs with a small cell charge. With the conditions of small cell charge, thermal neutron-induced SEUs account for 60% or more of the total neutron-induced SEUs. The SEU rate induced by atmospheric thermal neutrons can be estimated by an acceleration test using sup 2 sup 5 sup 2 Cf. (author)

  16. Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment

    Directory of Open Access Journals (Sweden)

    Zhongyu Cui

    2015-01-01

    Full Text Available Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular corrosion with the extension of exposure time, resulting in the reduction of the mechanical properties.

  17. In situ TEM studies of the shape evolution of Pd nanocrystals under oxygen and hydrogen environments at atmospheric pressure.

    Science.gov (United States)

    Zhang, Xun; Meng, Jun; Zhu, Beien; Yu, Jian; Zou, Shihui; Zhang, Ze; Gao, Yi; Wang, Yong

    2017-12-12

    We demonstrate an atomic scale TEM observation of shape evolutions of Pd nanocrystals under oxygen and hydrogen environments at atmospheric pressure. Combined with multi-scale structure reconstruction model calculations, the reshaping mechanism is fully understood.

  18. Measurements of gaseous mercury exchanges at the sediment-water, water-atmosphere and sediment-atmosphere interfaces of a tidal environment (Arcachon Bay, France).

    Science.gov (United States)

    Bouchet, Sylvain; Tessier, Emmanuel; Monperrus, Mathilde; Bridou, Romain; Clavier, Jacques; Thouzeau, Gerard; Amouroux, David

    2011-05-01

    The elemental mercury evasion from non-impacted natural areas is of significant importance in the global Hg cycle due to their large spatial coverage. Intertidal areas represent a dynamic environment promoting the transformations of Hg species and their subsequent redistribution. A major challenge remains in providing reliable data on Hg species variability and fluxes under typical transient tidal conditions found in such environment. Field experiments were thus carried out to allow the assessment and comparison of the magnitude of the gaseous Hg fluxes at the three interfaces, sediment-water, sediment-atmosphere and water-atmosphere of a mesotidal temperate lagoon (Arcachon Bay, Aquitaine, France) over three distinct seasonal conditions. The fluxes between the sediment-water and the sediment-atmosphere interfaces were directly evaluated with field flux chambers, respectively static or dynamic. Water-atmosphere fluxes were evaluated from ambient concentrations using a gas exchange model. The fluxes at the sediment-water interface ranged from -5.0 to 5.1 ng m(-2) h(-1) and appeared mainly controlled by diffusion. The occurrence of macrophytic covers (i.e.Zostera noltii sp.) enhanced the fluxes under light radiations. The first direct measurements of sediment-atmosphere fluxes are reported here. The exchanges were more intense and variable than the two other interfaces, ranging between -78 and 40 ng m(-2) h(-1) and were mostly driven by the overlying atmospheric Hg concentrations and superficial sediment temperature. The exchanges between the water column and the atmosphere, computed as a function of wind speed and gaseous mercury saturation ranged from 0.4 to 14.5 ng m(-2) h(-1). The flux intensities recorded over the intertidal sediments periodically exposed to the atmosphere were roughly 2 to 3 times higher than the fluxes of the other interfaces. The evasion of elemental mercury from emerged intertidal sediments is probably a significant pathway for Hg evasion in

  19. Flexible sample environment for high resolution neutron imaging at high temperatures in controlled atmosphere.

    Science.gov (United States)

    Makowska, Małgorzata G; Theil Kuhn, Luise; Cleemann, Lars N; Lauridsen, Erik M; Bilheux, Hassina Z; Molaison, Jamie J; Santodonato, Louis J; Tremsin, Anton S; Grosse, Mirco; Morgano, Manuel; Kabra, Saurabh; Strobl, Markus

    2015-12-01

    High material penetration by neutrons allows for experiments using sophisticated sample environments providing complex conditions. Thus, neutron imaging holds potential for performing in situ nondestructive measurements on large samples or even full technological systems, which are not possible with any other technique. This paper presents a new sample environment for in situ high resolution neutron imaging experiments at temperatures from room temperature up to 1100 °C and/or using controllable flow of reactive atmospheres. The design also offers the possibility to directly combine imaging with diffraction measurements. Design, special features, and specification of the furnace are described. In addition, examples of experiments successfully performed at various neutron facilities with the furnace, as well as examples of possible applications are presented. This covers a broad field of research from fundamental to technological investigations of various types of materials and components.

  20. Aviation Trends Related to Atmospheric Environment Safety Technologies Project Technical Challenges

    Science.gov (United States)

    Reveley, Mary S.; Withrow, Colleen A.; Barr, Lawrence C.; Evans, Joni K.; Leone, Karen M.; Jones, Sharon M.

    2014-01-01

    Current and future aviation safety trends related to the National Aeronautics and Space Administration's Atmospheric Environment Safety Technologies Project's three technical challenges (engine icing characterization and simulation capability; airframe icing simulation and engineering tool capability; and atmospheric hazard sensing and mitigation technology capability) were assessed by examining the National Transportation Safety Board (NTSB) accident database (1989 to 2008), incidents from the Federal Aviation Administration (FAA) accident/incident database (1989 to 2006), and literature from various industry and government sources. The accident and incident data were examined for events involving fixed-wing airplanes operating under Federal Aviation Regulation (FAR) Parts 121, 135, and 91 for atmospheric conditions related to airframe icing, ice-crystal engine icing, turbulence, clear air turbulence, wake vortex, lightning, and low visibility (fog, low ceiling, clouds, precipitation, and low lighting). Five future aviation safety risk areas associated with the three AEST technical challenges were identified after an exhaustive survey of a variety of sources and include: approach and landing accident reduction, icing/ice detection, loss of control in flight, super density operations, and runway safety.

  1. Visible and infrared extinction of atmospheric aerosol in the marine and coastal environment.

    Science.gov (United States)

    Kaloshin, Gennady A

    2011-05-10

    The microphysical model Marine Aerosol Extinction Profiles (MaexPro) for surface layer marine and coastal atmospheric aerosols, which is based on long-term observations of size distributions for 0.01-100 μm particles, is presented. The fundamental feature of the model is a parameterization of amplitudes and widths for aerosol modes of the aerosol size distribution function (ASDF) as functions of fetch and wind speed. The shape of the ASDF and its dependence on meteorological parameters, altitudes above the sea level (H), fetch (X), wind speed (U), and relative humidity is investigated. The model is primarily to characterize aerosols for the near-surface layer (within 25 m). The model is also applicable to higher altitudes within the atmospheric boundary layer, where the change in the vertical profile of aerosol is not very large. In this case, it is only valid for "clean" marine environments, in the absence of air pollution or any other major sources of continental aerosols, such desert dust or smoke from biomass burning. The spectral profiles of the aerosol extinction coefficients calculated by MaexPro are in good agreement with observational data and the numerical results obtained by the well-known Navy Aerosol Model and Advanced Navy Aerosol Model codes. Moreover, MaexPro was found to be an accurate and reliable instrument for investigation of the optical properties of atmospheric aerosols.

  2. Modelling Europa's interaction with Jupiter's magnetosphere: Influence of plumes in Europa's atmosphere on the plasma environment

    Science.gov (United States)

    Bloecker, A.; Saur, J.; Roth, L.

    2015-12-01

    We study the influence of plumes in Europa's atmosphere on the interaction with Jupiter's magnetosphere and the plasma environment. We apply a three-dimensional magnetohydrodynamic (MHD) model, which includes plasma production and loss due to electron impact ionization and dissociative recombination, and electromagnetic induction in a subsurface water ocean.The model considers the magnetospheric and ionospheric electrons separately. We show that an atmospherical inhomogeneity, such as a plume, affects the plasma interaction in the way that a pronounced north-south asymmetry in the near and the Alfvénic far field develops. Furthermore, a "small Alfvén winglet" within Europa's Alfvén wing forms. We also investigate if such signatures of atmospherical inhomogeneities are visible in magnetic field measurements of the Galileo magnetometer. In addition to our MHD model we apply an analytical approach based on the model by Saur et al. (2007) for our studies. We compare the model results with the observed magnetic field data from three flybys of Europa that occurred during the Alfvén wing crossing.

  3. Atmospheric mixing ratios of methyl ethyl ketone (2-butanone in tropical, boreal, temperate and marine environments

    Directory of Open Access Journals (Sweden)

    A. M. Yáñez-Serrano

    2016-09-01

    Full Text Available Methyl ethyl ketone (MEK enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs such as n-butane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with proton-transfer-reaction mass spectrometer (PTR-MS instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia. Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere.

  4. Study of different atmospheric environments associated to storms development in the Madeira Island

    Science.gov (United States)

    Couto, Flavio Tiago do

    The study aims to improve the understanding about different atmospheric environments leading to the development of storms associated with heavy precipitation in Madeira Island. For this purpose, four main goals have been considered: 1) To document the synoptic and mesoscale environments associated with heavy precipitation. 2) To characterize surface precipitation patterns that affected the island during some periods of significant accumulated precipitation using numerical modelling. 3) To study the relationship between surface precipitation patterns and mesoscale environments. 4) To highlight how the PhD findings obtained in the first three goals can be translated into an operational forecast context. Concerning the large scale environment, precipitation over the island was favoured by weather systems (e.g, mesoscale convective systems and low pressure systems), as well as by the meridional transport of high amount of moisture from a structure denominated as “Atmospheric River”. The tropical origin of this moisture is underscored, however, their impact on the precipitation in Madeira was not so high during the 10 winter seasons [2002 – 2012] studied. The main factor triggering heavy precipitation events over the island is related to the local orography. The steep terrain favours orographically-induced stationary precipitation over the highlands, although maximum of precipitation at coastal region may be produced by localized blocking effect. These orographic precipitating systems presented different structures, associated with shallow and deep convection. Essentially, the study shows that the combination of airflow dynamics, moist content, and orography is the major mechanism that produces precipitation over the island. These factors together with the event duration act to define the regions of excessive precipitation. Finally, the study highlights two useful points for the operational sector, regarding the meridional water vapour transport and local effects

  5. Atmospheric pollution in an urban environment by tree bark biomonitoring--part I: trace element analysis.

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Lahd Geagea, Majdi; Boutin, René

    2012-03-01

    Tree bark has been shown to be a useful biomonitor of past air quality because it accumulates atmospheric particulate matter (PM) in its outermost structure. Trace element concentrations of tree bark of more than 73 trees allow to elucidate the impact of past atmospheric pollution on the urban environment of the cities of Strasbourg and Kehl in the Rhine Valley. Compared to the upper continental crust (UCC) tree barks are strongly enriched in Mn, Ni, Cu, Zn, Cd and Pb. To assess the degree of pollution of the different sites in the cities, a geoaccumulation index I(geo) was applied. Global pollution by V, Ni, Cr, Sb, Sn and Pb was observed in barks sampled close to traffic axes. Cr, Mo, Cd pollution principally occurred in the industrial area. A total geoaccumulation index I(GEO-tot) was defined; it is based on the total of the investigated elements and allows to evaluate the global pollution of the studied environment by assembling the I(geo) indices on a pollution map. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. The effects of radionuclides in the atmosphere on weather, climate and environment

    International Nuclear Information System (INIS)

    Jager, D. de.

    1992-10-01

    A literature study on the effects of the released radionuclides in the atmosphere on weather, climate and environment are reported. In this report a science outlook of these effects is presented. The emissions generated by the electricity are the central issue. For the global effects the released krypton-85 (half-life time 10,78 years) which are caused by reprocessing factories would take an important role, but for local effects the releasing of short-living isotopes as xenon-133 and xenon-135 produced by nuclear reactors and radon-222 produced by mining activities must be taken into account. The production, emission and distribution of these related important isotopes are discussed, just like air-electric circuits (global), the chemistry of the atmosphere (local) and the consequences of it for the weather, climate and environment on earth. Radionuclides could affect on the development of the thunderstorm, rainfall, cloud formation, air dampness, acid- and aerosol formations and also indirect, for example, for the greenhouse effect and acid rainfall. (author). 133 refs., 22 figs., 11 tabs

  7. Focal and Ambient Processing of Built Environments: Intellectual and Atmospheric Experiences of Architecture

    Science.gov (United States)

    Rooney, Kevin K.; Condia, Robert J.; Loschky, Lester C.

    2017-01-01

    Neuroscience has well established that human vision divides into the central and peripheral fields of view. Central vision extends from the point of gaze (where we are looking) out to about 5° of visual angle (the width of one’s fist at arm’s length), while peripheral vision is the vast remainder of the visual field. These visual fields project to the parvo and magno ganglion cells, which process distinctly different types of information from the world around us and project that information to the ventral and dorsal visual streams, respectively. Building on the dorsal/ventral stream dichotomy, we can further distinguish between focal processing of central vision, and ambient processing of peripheral vision. Thus, our visual processing of and attention to objects and scenes depends on how and where these stimuli fall on the retina. The built environment is no exception to these dependencies, specifically in terms of how focal object perception and ambient spatial perception create different types of experiences we have with built environments. We argue that these foundational mechanisms of the eye and the visual stream are limiting parameters of architectural experience. We hypothesize that people experience architecture in two basic ways based on these visual limitations; by intellectually assessing architecture consciously through focal object processing and assessing architecture in terms of atmosphere through pre-conscious ambient spatial processing. Furthermore, these separate ways of processing architectural stimuli operate in parallel throughout the visual perceptual system. Thus, a more comprehensive understanding of architecture must take into account that built environments are stimuli that are treated differently by focal and ambient vision, which enable intellectual analysis of architectural experience versus the experience of architectural atmosphere, respectively. We offer this theoretical model to help advance a more precise understanding of the

  8. Multi-scale dynamic modeling of atmospheric pollution in urban environment

    International Nuclear Information System (INIS)

    Thouron, Laetitia

    2017-01-01

    Urban air pollution has been identified as an important cause of health impacts, including premature deaths. In particular, ambient concentrations of gaseous pollutants such as nitrogen dioxide (NO 2 ) and particulate matter (PM10 and PM2.5) are regulated, which means that emission reduction strategies must be put in place to reduce these concentrations in places where the corresponding regulations are not respected. Besides, air pollution can contribute to the contamination of other media, for example through the contribution of atmospheric deposition to runoff contamination. The multifactorial and multi-scale aspects of urban make the pollution sources difficult to identify. Indeed, the urban environment is a heterogeneous space characterized by complex architectural structures (old buildings alongside a more modern building, residential, commercial, industrial zones, roads, etc.), non-uniform atmospheric pollutant emissions and therefore the population exposure to pollution is variable in space and time. The modeling of urban air pollution aims to understand the origin of pollutants, their spatial extent and their concentration/deposition levels. Some pollutants have long residence times and can stay several weeks in the atmosphere (PM2.5) and therefore be transported over long distances, while others are more local (NO x in the vicinity of traffic). The spatial distribution of a pollutant will therefore depend on several factors, and in particular on the surfaces encountered. Air quality depends strongly on weather, buildings (canyon-street) and emissions. The aim of this thesis is to address some of these aspects by modeling: (1) urban background pollution with a transport-chemical model (Polyphemus / POLAIR3D), which makes it possible to estimate atmospheric pollutants by type of urban surfaces (roofs, walls and roadways), (2) street-level pollution by explicitly integrating the effects of the building in a three-dimensional way with a multi-scale model of

  9. Atmospheric pollution assessment from a mountainous environment in Southern Ghana: case study of Abetifi

    International Nuclear Information System (INIS)

    Palm, Linda Maud Naa-Dedei

    2016-07-01

    In the pursuit to improve man’s livelihood, human activities which include emission of heavy metals from various industries and sectors, as well as the past use of chemicals such as pesticides, polychlorinated biphenyls and flame retardants have often mobilized and redistributed natural substances and anthropogenic pollutants into the atmosphere, predisposing it to relatively high concentrations of such pollutants even in pristine areas in the environment. This study assessed the level of atmospheric pollution, contributing sources and human health exposure risk of persistent organic pollutants (POPs) along with selected heavy metals with focus on Abetifi, one of the highest altitude environments in Ghana. Passive sampling with polyurethane foam (PUF) as adsorbent was employed. Samplers were deployed every 84 days for two years. A total of 65 polyurethane foams were deployed and twelve (12) groups of analytes were considered together with their various isomers. High resolution gas chromatographic technique coupled with high resolution mass spectrometry (HRGC-HRMS) and electron capture detectors (ECD) were used in the analysis of the POPs. Besides, high performance liquid chromatography (HPLC) coupled with MS was employed in analysing the perfluorinated compounds (PFCs) while the heavy metals were analysed using Atomic Absorption Spectrometer (AAS). Principal Component Analysis (PCA) and UNMIX model were used to group pollution source contribution of all analytes (POPs and heavy metals) in this study. Diagnostic isomer and other predictive ratios were also employed for source apportionment of various individual analyte groups. Results revealed that polychlorinated dibenzo-furans gave with the least total mean concentration (0.074 pg/m 3 ) for the sampling period and polybrominated biphenyls gave the highest (55 pg/m 3 ). The pesticide group gave values in the order of DRINs (53 pg/m 3 ) > DDT (41 pg/m 3 ) > HCHs (28 pg/m 3 ). Data for perflourinated compounds

  10. Land-Atmosphere Interactions in Cold Environments (LATICE): The role of Atmosphere - Biosphere - Cryosphere - Hydrosphere interactions in a changing climate

    Science.gov (United States)

    Burkhart, J. F.; Tallaksen, L. M.; Stordal, F.; Berntsen, T.; Westermann, S.; Kristjansson, J. E.; Etzelmuller, B.; Hagen, J. O.; Schuler, T.; Hamran, S. E.; Lande, T. S.; Bryn, A.

    2015-12-01

    Climate change is impacting the high latitudes more rapidly and significantly than any other region of the Earth because of feedback processes between the atmosphere and the underlying surface. A warmer climate has already led to thawing of permafrost, reducing snow cover and a longer growing season; changes, which in turn influence the atmospheric circulation and the hydrological cycle. Still, many studies rely on one-way coupling between the atmosphere and the land surface, thereby neglecting important interactions and feedbacks. The observation, understanding and prediction of such processes from local to regional and global scales, represent a major scientific challenge that requires multidisciplinary scientific effort. The successful integration of earth observations (remote and in-situ data) and model development requires a harmonized research effort between earth system scientists, modelers and the developers of technologies and sensors. LATICE, which is recognized as a priority research area by the Faculty of Mathematics and Natural Sciences at the University of Oslo, aims to advance the knowledge base concerning land atmosphere interactions and their role in controlling climate variability and climate change at high northern latitudes. The consortium consists of an interdisciplinary team of experts from the atmospheric and terrestrial (hydrosphere, cryosphere and biosphere) research groups, together with key expertise on earth observations and novel sensor technologies. LATICE addresses critical knowledge gaps in the current climate assessment capacity through: Improving parameterizations of processes in earth system models controlling the interactions and feedbacks between the land (snow, ice, permafrost, soil and vegetation) and the atmosphere at high latitudes, including the boreal, alpine and artic zone. Assessing the influence of climate and land cover changes on water and energy fluxes. Integrating remote earth observations with in-situ data and

  11. Localized Corrosion Behavior of Type 304SS with a Silica Layer Under Atmospheric Corrosion Environments

    International Nuclear Information System (INIS)

    E. Tada; G.S. Frankel

    2006-01-01

    The U.S. Department of Energy (DOE) has proposed a potential repository for spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nevada. [I] The temperature could be high on the waste packages, and it is possible that dripping water or humidity could interact with rock dust particulate to form a thin electrolyte layer with concentrated ionic species. Under these conditions, it is possible that highly corrosion-resistant alloys (CRAs) used as packages to dispose the nuclear waste could suffer localized corrosion. Therefore, to better understand long-term corrosion performance of CRAs in the repository, it is important to investigate localized corrosion under a simulated repository environment. We measured open circuit potential (OCP) and galvanic current (i g ) for silica-coated Type 304SS during drying of salt solutions under controlled RH environments to clarify the effect of silica layer as a dust layer simulant on localized corrosion under atmospheric environments. Type 304SS was used as a relatively susceptible model CRA instead of the much more corrosion resistant alloys, such as Alloy 22, that are being considered as, waste package materials

  12. Design and Experiment of FBG-Based Icing Monitoring on Overhead Transmission Lines with an Improvement Trial for Windy Weather

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2014-12-01

    Full Text Available A scheme for monitoring icing on overhead transmission lines with fiber Bragg grating (FBG strain sensors is designed and evaluated both theoretically and experimentally. The influences of temperature and wind are considered. The results of field experiments using simulated ice loading on windless days indicate that the scheme is capable of monitoring the icing thickness within 0–30 mm with an accuracy of ±1 mm, a load cell error of 0.0308v, a repeatability error of 0.3328v and a hysteresis error is 0.026%. To improve the measurement during windy weather, a correction factor is added to the effective gravity acceleration, and the absolute FBG strain is replaced by its statistical average.

  13. Performance of sulfation and nitration plates used to monitor atmospheric pollutant deposition in a real environment

    Energy Technology Data Exchange (ETDEWEB)

    Noel, D.; Hechler, J.; Roberge, H.

    1989-01-01

    Sulfation and nitration plates were exposed outdoors for various periods of time to evaluate their performance in a real environment. These passive monitors are used to estimate the deposition of pollutants on metallic surfaces, and thus to evaluate the influence of the atmosphere on the corrosion. Single-column ion chromatography was used to determine the quantity of anions absorbed on the plates. This technique is better than other analytical procedures such as turbidimetry or colorimetry because passive monitors exposed in an atmosphere with a low degree of pollution can be analyzed without preconcentration. However, the pH of the sample to be injected on the chromatographic column must be adjusted to between 6.0 and 12.0 in order to obtain reproducible sulfate values. For sulfation plates, the additivity of the deposition process is excellent for a period of exposure up to 3 months, with a reproducibility of about 2%. For nitration plates, the deposition process is not cumulative due to a physical change of the monitor during exposure. The correlation between the amounts of sulfate found on sulfation snd nitration plates was also examined. 16 refs., 6 figs., 5 tabs.

  14. Performance of sulfation and nitration plates used to monitor atmospheric pollutant deposition in a real environment

    Science.gov (United States)

    Noël, Denis; Hechler, Jean-Jacques; Roberge, Hélène

    Sulfation and nitration plates were exposed outdoors for various periods of time to evaluate their performance in a real environment. These passive monitors are used to estimate the deposition of pollutants on metallic surfaces, and thus to evaluate the influence of the atmosphere on the corrosion. Single-column ion chromatography was used to determine the quantity of anions absorbed on the plates. This technique is better than other analytical procedures such as turbidimetry or colorimetry because passive monitors exposed in an atmosphere with a low degree of pollution can be analyzed without preconcentration. However, the pH of the sample to be injected on the Chromatographic column must be adjusted to between 6.0 and 12.0 in order to obtain reproducible sulfate values. For sulfation plates, the additivity of the deposition process is excellent for a period of exposure up to 3 months, with a reproducibility of about 2%. For nitration plates, the deposition process is not cumulative due to a physical change of the monitor during exposure. The correlation between the amounts of sulfate found on sulfation and nitration plates was also examined.

  15. Marshall Team Complete Testing for Lunar Atmosphere and Dust Environment Explorer

    Science.gov (United States)

    Swofford, Philip

    2013-01-01

    Dr. Huu Trinh and his team with the Propulsion Systems and Test Departments at Marshall Space Flight Center in Huntsville, Ala. successfully complete a simulated cold-flow test series on the propulsion system used for the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft. NASA Ames Research Center, Moffett Field, Calif., is leading NASA s work on the development of the LADEE spacecraft, and the Marshall center is the program office for the project. The spacecraft, scheduled for launch this fall, will orbit the Moon and gather information about the lunar atmosphere, conditions near the surface of the Moon, and collect samples of lunar dust. A thorough understanding of these characteristics will address long-standing unknowns, and help scientists understand other planetary bodies as well. The test team at the Marshall center conducted the cold flow test to identify how the fluid flows through the propulsion system feed lines, especially during critical operation modes. The test data will be used to assist the LADEE team in identifying any potential flow issues in the propulsion system, and allow them to address and correct them in advance of the launch.

  16. Impact of Urban Surface Roughness Length Parameterization Scheme on Urban Atmospheric Environment Simulation

    Directory of Open Access Journals (Sweden)

    Meichun Cao

    2014-01-01

    Full Text Available In this paper, the impact of urban surface roughness length z0 parameterization scheme on the atmospheric environment simulation over Beijing has been investigated through two sets of numerical experiments using the Weather Research and Forecasting model coupled with the Urban Canopy Model. For the control experiment (CTL, the urban surface z0 parameterization scheme used in UCM is the model default one. For another experiment (EXP, a newly developed urban surface z0 parameterization scheme is adopted, which takes into account the comprehensive effects of urban morphology. The comparison of the two sets of simulation results shows that all the roughness parameters computed from the EXP run are larger than those in the CTL run. The increased roughness parameters in the EXP run result in strengthened drag and blocking effects exerted by buildings, which lead to enhanced friction velocity, weakened wind speed in daytime, and boosted turbulent kinetic energy after sunset. Thermal variables (sensible heat flux and temperature are much less sensitive to z0 variations. In contrast with the CTL run, the EXP run reasonably simulates the observed nocturnal low-level jet. Besides, the EXP run-simulated land surface-atmosphere momentum and heat exchanges are also in better agreement with the observation.

  17. Measurement and simulation of the radiation environment in the lower atmosphere for dose assessment

    International Nuclear Information System (INIS)

    Pioch, Christian Dieter

    2012-01-01

    Flying personnel is occupationally exposed to rather high radiation levels due to secondary cosmic radiation. Therefore, the radiation environment induced in the lower atmosphere by galactic and solar cosmic radiation was characterized by means of particle transport calculations using GEANT4. These calculations were validated with continuous measurements of the energy spectra of secondary neutrons with Bonner sphere spectrometers at the Zugspitze mountain and near the North Pole. The response of these instruments was determined with GEANT4 and for the first time experimentally verified at high neutron energies (244 and 387 MeV). Route doses for aircrews along typical long-haul flights were determined for galactic and solar cosmic radiation using most recent data on the magnetospheric field and primary cosmic radiation.

  18. Microbial inactivation and pesticide removal by remote exposure of atmospheric air plasma in confined environments.

    Science.gov (United States)

    Heo, Nam Su; Lee, Moon-Keun; Kim, Gi Wook; Lee, Seok Jae; Park, Jung Youn; Park, Tae Jung

    2014-01-01

    Microbial inactivation and pesticide removal by remote exposure of atmospheric air plasma were investigated in confined environments, including an airtight box and commercial refrigerator. The relative sterilization ratios of remote plasma exposure in an airtight box were found to be affected by the distance from the plasma generator, the volume of box and the time of irradiation; however, over 99% saturation was obtained within only 120 s in all experiments. The sterilization of microorganisms and the removal of pesticide in a refrigerator with a volume of 292 l were also successfully achieved, resulting in over 99% inactivation or decontamination in a few minutes. Considering the reported results by direct plasma exposure and circulation, it can be concluded that the confined environment enhances the efficient irradiation of plasma by eliminating air flow. This system can be applied to the storage to keep agricultural products freshly and exclusion of harmful materials on the products. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. The ward atmosphere important for the psychosocial work environment of nursing staff in psychiatric in-patient care.

    Science.gov (United States)

    Tuvesson, Hanna; Wann-Hansson, Christine; Eklund, Mona

    2011-06-16

    The nursing staff working in psychiatric care have a demanding work situation, which may be reflected in how they view their psychosocial work environment and the ward atmosphere. The aims of the present study were to investigate in what way different aspects of the ward atmosphere were related to the psychosocial work environment, as perceived by nursing staff working in psychiatric in-patient care, and possible differences between nurses and nurse assistants. 93 nursing staff working at 12 general psychiatric in-patient wards in Sweden completed two questionnaires, the Ward Atmosphere Scale and the QPSNordic 34+. Data analyses included descriptive statistics, the Mann-Whitney U-test, Spearman rank correlations and forward stepwise conditional logistic regression analyses. The data revealed that there were no differences between nurses and nurse assistants concerning perceptions of the psychosocial work environment and the ward atmosphere. The ward atmosphere subscales Personal Problem Orientation and Program Clarity were associated with a psychosocial work environment characterized by Empowering Leadership. Program Clarity was related to the staff's perceived Role Clarity, and Practical Orientation and Order and Organization were positively related to staff perceptions of the Organizational Climate. The results from the present study indicate that several ward atmosphere subscales were related to the nursing staff's perceptions of the psychosocial work environment in terms of Empowering Leadership, Role Clarity and Organizational Climate. Improvements in the ward atmosphere could be another way to accomplish improvements in the working conditions of the staff, and such improvements would affect nurses and nurse assistants in similar ways.

  20. The ward atmosphere important for the psychosocial work environment of nursing staff in psychiatric in-patient care

    Directory of Open Access Journals (Sweden)

    Wann-Hansson Christine

    2011-06-01

    Full Text Available Abstract Background The nursing staff working in psychiatric care have a demanding work situation, which may be reflected in how they view their psychosocial work environment and the ward atmosphere. The aims of the present study were to investigate in what way different aspects of the ward atmosphere were related to the psychosocial work environment, as perceived by nursing staff working in psychiatric in-patient care, and possible differences between nurses and nurse assistants. Methods 93 nursing staff working at 12 general psychiatric in-patient wards in Sweden completed two questionnaires, the Ward Atmosphere Scale and the QPSNordic 34+. Data analyses included descriptive statistics, the Mann-Whitney U-test, Spearman rank correlations and forward stepwise conditional logistic regression analyses. Results The data revealed that there were no differences between nurses and nurse assistants concerning perceptions of the psychosocial work environment and the ward atmosphere. The ward atmosphere subscales Personal Problem Orientation and Program Clarity were associated with a psychosocial work environment characterized by Empowering Leadership. Program Clarity was related to the staff's perceived Role Clarity, and Practical Orientation and Order and Organization were positively related to staff perceptions of the Organizational Climate. Conclusions The results from the present study indicate that several ward atmosphere subscales were related to the nursing staff's perceptions of the psychosocial work environment in terms of Empowering Leadership, Role Clarity and Organizational Climate. Improvements in the ward atmosphere could be another way to accomplish improvements in the working conditions of the staff, and such improvements would affect nurses and nurse assistants in similar ways.

  1. The ward atmosphere important for the psychosocial work environment of nursing staff in psychiatric in-patient care

    Science.gov (United States)

    2011-01-01

    Background The nursing staff working in psychiatric care have a demanding work situation, which may be reflected in how they view their psychosocial work environment and the ward atmosphere. The aims of the present study were to investigate in what way different aspects of the ward atmosphere were related to the psychosocial work environment, as perceived by nursing staff working in psychiatric in-patient care, and possible differences between nurses and nurse assistants. Methods 93 nursing staff working at 12 general psychiatric in-patient wards in Sweden completed two questionnaires, the Ward Atmosphere Scale and the QPSNordic 34+. Data analyses included descriptive statistics, the Mann-Whitney U-test, Spearman rank correlations and forward stepwise conditional logistic regression analyses. Results The data revealed that there were no differences between nurses and nurse assistants concerning perceptions of the psychosocial work environment and the ward atmosphere. The ward atmosphere subscales Personal Problem Orientation and Program Clarity were associated with a psychosocial work environment characterized by Empowering Leadership. Program Clarity was related to the staff's perceived Role Clarity, and Practical Orientation and Order and Organization were positively related to staff perceptions of the Organizational Climate. Conclusions The results from the present study indicate that several ward atmosphere subscales were related to the nursing staff's perceptions of the psychosocial work environment in terms of Empowering Leadership, Role Clarity and Organizational Climate. Improvements in the ward atmosphere could be another way to accomplish improvements in the working conditions of the staff, and such improvements would affect nurses and nurse assistants in similar ways. PMID:21679430

  2. Tritium distribution in the environment in the vicinity of a chronic atmospheric source-assessment of the steady state hypothesis

    International Nuclear Information System (INIS)

    Murphy, C.E. Jr.; Bauer, L.R.; Zeigler, C.C.

    1990-01-01

    The Savannah River Site (SRS) is a major radionuclide production center. Tritium has been released to the atmosphere over the 36 year period of operation. The tritiated water concentration of the atmosphere, rain, vegetation and food have been routinely monitored during this period. Special studies have been made of tritium in soils and in the organic fractions of these same materials. The available data suggest that the average tritium concentration in the components of the terrestrial environment have approached a steady state with the two main sources of tritium, rainfall and atmospheric water vapor

  3. A landscape-scale approach to examining the fate of atmospherically derived industrial metals in the surficial environment.

    Science.gov (United States)

    Stromsoe, Nicola; Marx, Samuel K; McGowan, Hamish A; Callow, Nikolaus; Heijnis, Henk; Zawadzki, Atun

    2015-02-01

    Industrial metals are now ubiquitous within the atmosphere and their deposition represents a potential source of contamination to surficial environments. Few studies, however, have examined the environmental fate of atmospheric industrial metals within different surface environments. In this study, patterns of accumulation of atmospherically transported industrial metals were investigated within the surface environments of the Snowy Mountains, Australia. Metals, including Pb, Sb, Cr and Mo, were enriched in aerosols collected in the Snowy Mountains by 3.5-50 times pre-industrial concentrations. In sedimentary environments (soils, lakes and reservoirs) metals showed varying degrees of enrichment. Differences were attributed to the relative degree of atmospheric input, metal sensitivity to enrichment, catchment area and metal behaviour following deposition. In settings where atmospheric deposition dominated (ombrotrophic peat mires in the upper parts of catchments), metal enrichment patterns most closely resembled those in collected aerosols. However, even in these environments significant dilution (by 5-7 times) occurred. The most sensitive industrial metals (those with the lowest natural concentration; Cd, Ag, Sb and Mo) were enriched throughout the studied environments. However, in alpine tarn-lakes no other metals were enriched, due to the dilution of pollutant-metals by catchment derived sediment. In reservoirs, which were located lower within catchments, industrial metals exhibited more complex patterns. Particle reactive metals (e.g. Pb) displayed little enrichment, implying that they were retained up catchment, whereas more soluble metals (e.g., Cu and Zn) showed evidence of concentration. These same metals (Cu and Zn) were depleted in soils, implying that they are preferentially transported through catchments. Enrichment of other metals (e.g. Cd) varied between reservoirs as a function of contributing catchment area. Overall this study showed that the fate

  4. Prevalence and sources of polychlorinated biphenyls in the atmospheric environment of Lake Victoria, East Africa.

    Science.gov (United States)

    Arinaitwe, Kenneth; Muir, Derek C G; Kiremire, Bernard T; Fellin, Phil; Li, Henrik; Teixeira, Camilla; Mubiru, Drake N

    2018-02-01

    The large surface area of Lake Victoria (about 68,800 km 2 ) makes it vulnerable to high atmospheric deposition of chemical pollutants. We present measurements of polychlorinated biphenyls (PCBs) from the lake's atmospheric environment. High volume air (24 h) samples were collected within the northern Lake Victoria watershed in Uganda over two periods; 1999-2004 [at Kakira (KAK) and Entebbe (EBB)] and 2008-2010 (at EBB only). Precipitation samples were also collected monthly during the 2008-2010 period at EBB. Analysis for PCBs was done using GC-μECD in a dual column approach. The ranges of ΣPCB concentrations in the KAK air samples were 154-462 pg m -3 (KAK 1999-2000), 26.7-226 pg m -3 (KAK 2003-2004), 27.0-186 pg m -3 (EBB 2003), 46.8-174 pg m -3 (EBB 2004), 19.2-128 pg m -3 (EBB 2008), 45.8-237 pg m -3 (EBB 2009) and 65.6-244 pg m -3 (EBB 2010). The di-, tri-, tetra- and penta-PCBs were predominant in air sample sets while the tetra- and penta-PCBs were predominant in precipitation samples. The mean flux of ΣPCBs in the precipitation samples was 26.9 ng m -2 (range of 14.8-41.5 and median of 27.5). Concentrations at EBB were lower than those reported elsewhere for urban sites in the East and Central African region. Multivariate analysis and analysis of air mass movements suggested influence of combustion sources on the PCB profiles from the region, especially, from the major East African urbanized regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Radiation exposure of airline crew members to the atmospheric ionizing radiation environment

    International Nuclear Information System (INIS)

    Angelis, G. De; Ballard, T.; Lagorio, S.; Verdecchia, A.

    2000-01-01

    All risk assessment techniques for possible health effects from low dose rate radiation exposure should combine knowledge both of the radiation environment and of the biological response, whose effects (e.g. carcinogenesis) are usually evaluated through mathematical models and/or animal and cell experiments. Data on human exposure to low dose rate radiation exposure and its effects are not readily available, especially with regards to stochastic effects, related to carcinogenesis and therefore to cancer risks, for which the event probability increases with increasing radiation exposure. The largest source of such data might be airline flight personnel, if enrolled for studies on health effects induced by the cosmic-ray generated atmospheric ionizing radiation, whose total dose, increasing over the years, might cause delayed radiation-induced health effects, with the high-LET and highly ionizing neutron component typical of atmospheric radiation. In 1990 flight personnel has been given the status of 'occupationally exposed to radiation' by the International Commission for Radiation Protection (ICRP), with a received radiation dose that is at least twice larger than that of the general population. The studies performed until now were limited in scope and cohort size, and moreover no information whatsoever on radiation occupational exposure (e.g. dose, flight hours, route haul, etc.) was used in the analysis, so no correlation has been until now possible between atmospheric ionizing radiation and (possibly radiation-induced) observed health effects. Our study addresses the issues, by considering all Italian civilian airline flight personnel, both cockpit and cabin crew members, with about 10,000 people selected, whose records on work history and actual flights (route, aircraft type, date, etc. for each individual flight for each person where possible) are considered. Data on actual flight routes and profiles have been obtained for the whole time frame. The actual dose

  6. Premar-2: a Monte Carlo code for radiative transport simulation in atmospheric environments

    Energy Technology Data Exchange (ETDEWEB)

    Cupini, E. [ENEA, Centro Ricerche Ezio Clementel, Bologna, (Italy). Dipt. Innovazione

    1999-07-01

    The peculiarities of the PREMAR-2 code, aimed at radiation transport Monte Carlo simulation in atmospheric environments in the infrared-ultraviolet frequency range, are described. With respect to the previously developed PREMAR code, besides plane multilayers, spherical multilayers and finite sequences of vertical layers, each one with its own atmospheric behaviour, are foreseen in the new code, together with the refraction phenomenon, so that long range, highly slanted paths can now be more faithfully taken into account. A zenithal angular dependence of the albedo coefficient has moreover been introduced. Lidar systems, with spatially independent source and telescope, are allowed again to be simulated, and, in this latest version of the code, sensitivity analyses to be performed. According to this last feasibility, consequences on radiation transport of small perturbations in physical components of the atmospheric environment may be analyze and the related effects on searched results estimated. The availability of a library of physical data (reaction coefficients, phase functions and refraction indexes) is required by the code, providing the essential features of the environment of interest needed of the Monte Carlo simulation. Variance reducing techniques have been enhanced in the Premar-2 code, by introducing, for instance, a local forced collision technique, especially apt to be used in Lidar system simulations. Encouraging comparisons between code and experimental results carried out at the Brasimone Centre of ENEA, have so far been obtained, even if further checks of the code are to be performed. [Italian] Nel presente rapporto vengono descritte le principali caratteristiche del codice di calcolo PREMAR-2, che esegue la simulazione Montecarlo del trasporto della radiazione elettromagnetica nell'atmosfera, nell'intervallo di frequenza che va dall'infrarosso all'ultravioletto. Rispetto al codice PREMAR precedentemente sviluppato, il codice

  7. Creating a store environment that encourages buying: A study on sight atmospherics

    OpenAIRE

    Yolande Hefer; Elsa C Nell

    2015-01-01

    More than ever, consumers respond to more than just the physical product when making a decision to purchase a product. One of the most noteworthy features of a product is the atmosphere of the place in which the product is bought. From time to time, the store atmosphere is more powerful than the product itself. This study focused specifically on the most important atmospheric element – sight. The main research question explored the effect of sight atmospherics on consumer perceptions. Explora...

  8. Nuclear fuel particles in the environment - characteristics, atmospheric transport and skin doses

    International Nuclear Information System (INIS)

    Poellaenen, R.

    2002-05-01

    In the present thesis, nuclear fuel particles are studied from the perspective of their characteristics, atmospheric transport and possible skin doses. These particles, often referred to as 'hot' particles, can be released into the environment, as has happened in past years, through human activities, incidents and accidents, such as the Chernobyl nuclear power plant accident in 1986. Nuclear fuel particles with a diameter of tens of micrometers, referred to here as large particles, may be hundreds of kilobecquerels in activity and even an individual particle may present a quantifiable health hazard. The detection of individual nuclear fuel particles in the environment, their isolation for subsequent analysis and their characterisation are complicated and require well-designed sampling and tailored analytical methods. In the present study, the need to develop particle analysis methods is highlighted. It is shown that complementary analytical techniques are necessary for proper characterisation of the particles. Methods routinely used for homogeneous samples may produce erroneous results if they are carelessly applied to radioactive particles. Large nuclear fuel particles are transported differently in the atmosphere compared with small particles or gaseous species. Thus, the trajectories of gaseous species are not necessarily appropriate for calculating the areas that may receive large particle fallout. A simplified model and a more advanced model based on the data on real weather conditions were applied in the case of the Chernobyl accident to calculate the transport of the particles of different sizes. The models were appropriate in characterising general transport properties but were not able to properly predict the transport of the particles with an aerodynamic diameter of tens of micrometers, detected at distances of hundreds of kilometres from the source, using only the current knowledge of the source term. Either the effective release height has been higher

  9. Nuclear fuel particles in the environment - characteristics, atmospheric transport and skin doses

    Energy Technology Data Exchange (ETDEWEB)

    Poellaenen, R

    2002-05-01

    In the present thesis, nuclear fuel particles are studied from the perspective of their characteristics, atmospheric transport and possible skin doses. These particles, often referred to as 'hot' particles, can be released into the environment, as has happened in past years, through human activities, incidents and accidents, such as the Chernobyl nuclear power plant accident in 1986. Nuclear fuel particles with a diameter of tens of micrometers, referred to here as large particles, may be hundreds of kilobecquerels in activity and even an individual particle may present a quantifiable health hazard. The detection of individual nuclear fuel particles in the environment, their isolation for subsequent analysis and their characterisation are complicated and require well-designed sampling and tailored analytical methods. In the present study, the need to develop particle analysis methods is highlighted. It is shown that complementary analytical techniques are necessary for proper characterisation of the particles. Methods routinely used for homogeneous samples may produce erroneous results if they are carelessly applied to radioactive particles. Large nuclear fuel particles are transported differently in the atmosphere compared with small particles or gaseous species. Thus, the trajectories of gaseous species are not necessarily appropriate for calculating the areas that may receive large particle fallout. A simplified model and a more advanced model based on the data on real weather conditions were applied in the case of the Chernobyl accident to calculate the transport of the particles of different sizes. The models were appropriate in characterising general transport properties but were not able to properly predict the transport of the particles with an aerodynamic diameter of tens of micrometers, detected at distances of hundreds of kilometres from the source, using only the current knowledge of the source term. Either the effective release height has

  10. Physics and applications of atmospheric non-thermal air plasma with reference to environment

    Science.gov (United States)

    Marode, E.; Djermoune, D.; Dessante, P.; Deniset, C.; Ségur, P.; Bastien, F.; Bourdon, A.; Laux, C.

    2009-12-01

    Since air is a natural part of our environment, special attention is given to the study of plasmas in air at atmospheric pressure and their applications. This fact promoted the study of electrical conduction in air-like mixtures, i.e. mixtures containing an electronegative gas component. If the ionization growth is not limited its temporal evolution leads to spark formation, i.e. a thermal plasma of several thousand kelvins in a quasi-local thermodynamic equilibrium state. But before reaching such a thermal state, a plasma sets up where the electrons increase their energy characterized by an electron temperature Te much higher than that of heavy species T or T+ for the ions. Since the plasma is no longer characterized by only one temperature T, it is said to be in a non-thermal plasma (NTP) state. Practical ways are listed to prevent electron ionization from going beyond the NTP states. Much understanding of such NTP may be gathered from the study of the simple paradigmatic case of a discharge induced between a sharp positively stressed point electrode facing a grounded negative plane electrode. Some physical properties will be gathered from such configurations and links underlined between these properties and some associated applications, mostly environmental. Aerosol filtration and electrostatic precipitators, pollution control by removal of hazardous species contained in flue gas exhaust, sterilization applications for medical purposes and triggering fuel combustion in vehicle motors are among such applications nowadays.

  11. Corrosion Behavior of 7B04 Al-alloy in Simulated Marine Atmospheric Environment

    Directory of Open Access Journals (Sweden)

    WANG Chenguang

    2017-01-01

    Full Text Available The corrosion of aluminum alloy in marine atmospheric environment was an essential electrochemical corrosion under thin electrolyte film, which was different from the corrosion in bulk solution, the corrosion rate was related to the thickness and composition of thin electrolyte film. The relationship among film thickness, relative humidity and salt deposit on aluminum alloy surface was established and verified by experiment. The electrochemical properties of 7B04 Al-alloy under thin electrolyte film with different thickness and different NaCl concentration were studied. The results indicate that the free-corrosion potential of 7B04 Al-alloy under thin electrolyte film is easier to reach steady state than that in bulk solution, both free-corrosion potential and corrosion rate are higher under thin electrolyte film. With the decrease of film thickness, the cathodic polarization current density of 7B04 Al-alloy increases, and the anode reaction is suppressed. With the increase of NaCl concentration in thin electrolyte film, the free-corrosion potential of 7B04 Al-alloy decreases, and the corrosion rate increases, but the polarization of the anode and cathode have little effect on the change of NaCl concentration. The free-corrosion potential of 7B04 Al-alloy is no longer changed when the mass fraction of NaCl reaches 5%.

  12. Testimony presented to the Committee on Science and Technology's Subcommittee on Environment and the Atmosphere

    International Nuclear Information System (INIS)

    Richmond, C.R.

    1976-03-01

    This report contains the basis for oral testimony to the House Committee on Science and Technology's Subcommittee on Environment and the Atmosphere in November 1975. The subject of the hearings was ''Effects and Costs of Long-term Exposure to Low Levels of Manmade Pollutants'' and the purpose of the hearings was to increase the awareness of low-level pollution and its impacts on human health, agriculture and climate. This report contains information related to impacts of low-level pollutants on human health. I have attempted to point out the major adverse health effects (e.g., carcinogenic, mutagenic and teratogenic) that may result from chronic exposure to low-level pollutants. Also addressed are important questions such as what do we know about dose-response relations for chronic exposure to pollutants and how can we establish comparisons with knowledge obtained from exposure to ionizing radiations. The report also considers the wisdom of extrapolating from health effects data obtained from acute, high-level exposures to chronic, low-level exposure conditions. Lastly, a few examples of the societal costs related to low-level pollutant exposure are presented

  13. ENTRYSAT: A 3U Cubesat to Study the Re-Entry Atmospheric Environment

    Science.gov (United States)

    Garcia, R. F.; Chaix, J.; Mimoun, D.; EntrySat student Team

    2014-04-01

    The EntrySat is a 3U CubeSat designed to study the uncontrolled atmospheric re-entry. The project, developed by ISAE in collaboration with ONERA, is funded by CNES and is intended to be launched in January 2016, in the context of the QB50 network. The scientific goal is to relate the kinematics of the satellite with the aerothermodynamic environment during re-entry. In particular, data will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. According to these requirements, the satellite will measure the temperature, pressure, heat flux, and drag force during re-entry, as well as the trajectory and attitude of the satellite. One of the major technological challenges is the retrieval of data during the re-entry phase, which will be based on the Iridium satellite network. The system design is based on the use of commercial COTS components, and is mostly developed by students from ISAE. As such, the EntrySat has an important educational value in the formation of young engineers.

  14. Observations on the use of membrane filtration and liquid impingement to collect airborne microorganisms in various atmospheric environments

    Science.gov (United States)

    Griffin, Dale W.; Gonzalez, C.; Teigell, N.; Petrosky, T.; Northup, D.E.; Lyles, M.

    2011-01-01

    The influence of sample-collection-time on the recovery of culturable airborne microorganisms using a low-flow-rate membrane-filtration unit and a high-flow-rate liquid impinger were investigated. Differences in recoveries were investigated in four different atmospheric environments, one mid-oceanic at an altitude of ~10.0 m, one on a mountain top at an altitude of ~3,000.0 m, one at ~1.0 m altitude in Tallahassee, Florida, and one at ~1.0 m above ground in a subterranean-cave. Regarding use of membrane filtration, a common trend was observed: the shorter the collection period, the higher the recovery of culturable bacteria and fungi. These data also demonstrated that lower culturable counts were common in the more remote mid-oceanic and mountain-top atmospheric environments with bacteria, fungi, and total numbers averaging (by sample time or method categories) extreme' atmospheric environments and thus the use of a 'limited' methodology in these environments must be taken into account; and (4) the atmosphere culls, i.e., everything is not everywhere. ?? 2010 US Government.

  15. Windy Mars: A Dynamic Planet as Seen by the HiRISE Camera

    Science.gov (United States)

    Bridges, N. T.; Geissler, P. E.; McEwen, A. S.; Thomson, B. J.; Chuang, F. C.; Herkenhoff, K. E.; Keszthelyi, L. P.; Martnez-Alonso, S.

    2007-01-01

    With a dynamic atmosphere and a large supply of particulate material, the surface of Mars is heavily influenced by wind-driven, or aeolian, processes. The High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter (MRO) provides a new view of Martian geology, with the ability to see decimeter-size features. Current sand movement, and evidence for recent bedform development, is observed. Dunes and ripples generally exhibit complex surfaces down to the limits of resolution. Yardangs have diverse textures, with some being massive at HiRISE scale, others having horizontal and cross-cutting layers of variable character, and some exhibiting blocky and polygonal morphologies. 'Reticulate' (fine polygonal texture) bedforms are ubiquitous in the thick mantle at the highest elevations.

  16. Overview of the atmospheric ionizing radiation environment monitoring by Bulgarian build instruments

    Science.gov (United States)

    Dachev, Tsvetan; Tomov, Borislav; Matviichuk, Yury; Dimitrov, Plamen; Spurny, Frantisek; Ploc, Ondrej; Uchihori, Yukio; Flueckiger, Erwin; Kudela, Karel; Benton, Eric

    2012-10-01

    Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating risks for their health. Spacecraft and aircraft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and to secondary radiation produced in the atmosphere, the vehicle structure and its contents. The aircraft crew monitoring is required by the following recommendations of the International Commission on Radiological Protection (ICRP) (ICRP 1990), the European Union (EU) introduced a revised Basic Safety Standards Directive (EC 1997) which, inter alia, included the exposure to cosmic radiation. This approach has been also adopted in other official documents (NCRP 2002). In this overview we present the results of ground based, mountain peaks, aircraft, balloon and rocket radiation environment monitoring by means of a Si-diode energy deposition spectrometer Liulin type developed first in Bulgarian Academy of Sciences (BAS) for the purposes of the space radiation monitoring at MIR and International Space Station (ISS). These spectrometers-dosemeters are further developed, calibrated and used by scientific groups in different countries. Calibration procedures of them are performed at different accelerators including runs in the CERN high-energy reference field, simulating the radiation field at 10 km altitude in the atmosphere and with heavy ions in Chiba, Japan HIMAC accelerator were performed also. The long term aircraft data base were accumulated using specially developed battery operated instrument in 2001-2009 years onboard of A310-300 aircrafts of Czech Air Lines, during 24 about 2 months runs with more than 2000 flights and 13500 flight hours on routes over the Atlantic Ocean mainly. The obtained experimental data are compared with computational models like CARI and EPCARD. The

  17. A Dropsonde UAV for Atmospheric Sensing in a Turbulent Environment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Dropsondes are one of the primary atmospheric measurement tools available to researchers. Current dropsondes are deployed with a free fall parachute trajectory,...

  18. First Results from NASA's Lunar Atmosphere and Dust Environment Explorer (LADEE)

    Science.gov (United States)

    Elphic, R. C.; Colaprete, A.; Horanyi, M.; Mahaffy, P. R.; Delory, G. T.; Noble, S. K.; Boroson, D.; Hine, B.; Salute, J.

    2013-12-01

    As of early August, 2013, the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission is scheduled for launch on a Minotaur V rocket from Wallops Flight Facility during a five-day launch period that opens on Sept. 6, 2013 (early Sept. 7 UTC). LADEE will address 40 year-old mysteries of the lunar atmosphere and the question of levitated lunar dust. It will also pioneer the next generation of optical space communications. LADEE will assess the composition of the lunar atmosphere and investigate the processes that control its distribution and variability, including sources, sinks, and surface interactions. LADEE will also determine whether dust is present in the lunar exosphere, and reveal its sources and variability. These investigations are relevant to our understanding of surface boundary exospheres and dust processes occurring at many objects throughout the solar system, address questions regarding the origin and evolution of lunar volatiles, and have potential implications for future exploration activities. Following a successful launch, LADEE will enter a series of phasing orbits, which allows the spacecraft to arrive at the Moon at the proper time and phase. This approach accommodates any dispersion in the Minotaur V launch injection. LADEE's arrival at the moon depends on the launch date, but with the Sept. 6 launch date it should arrive at the Moon in early October. The spacecraft will approach the moon from its leading edge, travel behind the Moon out of sight of the Earth, and then re-emerge and execute a three-minute Lunar Orbit Insertion maneuver. This will place LADEE in an elliptical retrograde equatorial orbit with an orbital period of approximately 24 hours. A series of maneuvers is then performed to reduce the orbit to become nearly circular with a 156-mile (250-kilometer) altitude. Spacecraft checkout and science instrument commissioning will commence in early-October and will nominally span 30 days but can be extended for an additional 30

  19. Creating a store environment that encourages buying: A study on sight atmospherics

    Directory of Open Access Journals (Sweden)

    Yolande Hefer

    2015-11-01

    Full Text Available More than ever, consumers respond to more than just the physical product when making a decision to purchase a product. One of the most noteworthy features of a product is the atmosphere of the place in which the product is bought. From time to time, the store atmosphere is more powerful than the product itself. This study focused specifically on the most important atmospheric element – sight. The main research question explored the effect of sight atmospherics on consumer perceptions. Explorative research was conducted together with qualitative research by means of focus groups. Purposive sampling was deemed the most appropriate sampling method for this study. The findings indicated that sight atmospherics can influence consumers’ perceptions either subconsciously or consciously, and have a direct influence on the amount of time consumers spend in a specific store. Consumers perceived sight atmospherics as a tool to establish a ‘purchasing’ atmosphere and as a means of communication to represent the brand of the store. It was established that sight atmospherics create visual attraction and stimulation with consumers, and that they contribute to the image and the character of the store.

  20. Atmospheric refraction effects on optical-infrared sensor performance in a littoral-maritime environment

    NARCIS (Netherlands)

    Fritz, P.; Moerman, M.M.; Jong, A.N.; Leeuw, G. de; Winkel, H.

    2004-01-01

    During a number of transmission experiments over littoral waters, quantitative measurements of atmospheric refraction phenomena were carried out to determine the range performance of optical–IR sensors. Examples of distortion and intensity gain generated by spatial variations of the atmospheric

  1. Climate and atmosphere simulator for experiments on ecological systems in changing environments.

    Science.gov (United States)

    Verdier, Bruno; Jouanneau, Isabelle; Simonnet, Benoit; Rabin, Christian; Van Dooren, Tom J M; Delpierre, Nicolas; Clobert, Jean; Abbadie, Luc; Ferrière, Régis; Le Galliard, Jean-François

    2014-01-01

    Grand challenges in global change research and environmental science raise the need for replicated experiments on ecosystems subjected to controlled changes in multiple environmental factors. We designed and developed the Ecolab as a variable climate and atmosphere simulator for multifactor experimentation on natural or artificial ecosystems. The Ecolab integrates atmosphere conditioning technology optimized for accuracy and reliability. The centerpiece is a highly contained, 13-m(3) chamber to host communities of aquatic and terrestrial species and control climate (temperature, humidity, rainfall, irradiance) and atmosphere conditions (O2 and CO2 concentrations). Temperature in the atmosphere and in the water or soil column can be controlled independently of each other. All climatic and atmospheric variables can be programmed to follow dynamical trajectories and simulate gradual as well as step changes. We demonstrate the Ecolab's capacity to simulate a broad range of atmospheric and climatic conditions, their diurnal and seasonal variations, and to support the growth of a model terrestrial plant in two contrasting climate scenarios. The adaptability of the Ecolab design makes it possible to study interactions between variable climate-atmosphere factors and biotic disturbances. Developed as an open-access, multichamber platform, this equipment is available to the international scientific community for exploring interactions and feedbacks between ecological and climate systems.

  2. Analysis of Aviation Safety Reporting System Incident Data Associated with the Technical Challenges of the Atmospheric Environment Safety Technology Project

    Science.gov (United States)

    Withrow, Colleen A.; Reveley, Mary S.

    2014-01-01

    This study analyzed aircraft incidents in the NASA Aviation Safety Reporting System (ASRS) that apply to two of the three technical challenges (TCs) in NASA's Aviation Safety Program's Atmospheric Environment Safety Technology Project. The aircraft incidents are related to airframe icing and atmospheric hazards TCs. The study reviewed incidents that listed their primary problem as weather or environment-nonweather between 1994 and 2011 for aircraft defined by Federal Aviation Regulations (FAR) Parts 121, 135, and 91. The study investigated the phases of flight, a variety of anomalies, flight conditions, and incidents by FAR part, along with other categories. The first part of the analysis focused on airframe-icing-related incidents and found 275 incidents out of 3526 weather-related incidents over the 18-yr period. The second portion of the study focused on atmospheric hazards and found 4647 incidents over the same time period. Atmospheric hazards-related incidents included a range of conditions from clear air turbulence and wake vortex, to controlled flight toward terrain, ground encounters, and incursions.

  3. Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

    Science.gov (United States)

    Tsai, Wen-Tien

    2017-01-01

    Among the halogenated hydrocarbons, chloromethanes (i.e., methyl chloride, CH3Cl; methylene chloride, CH2Cl2; chloroform, CHCl3; and carbon tetrachloride, CCl4) play a vital role due to their extensive uses as solvents and chemical intermediates. This article aims to review their main chemical/physical properties and commercial/industrial uses, as well as the environment and health hazards posed by them and their toxic decomposition products. The environmental properties (including atmospheric lifetime, radiative efficiency, ozone depletion potential, global warming potential, photochemical ozone creation potential, and surface mixing ratio) of these chlorinated methanes are also reviewed. In addition, this paper further discusses their atmospheric fates and human health implications because they are apt to reside in the lower atmosphere when released into the environment. According to the atmospheric degradation mechanism, their toxic degradation products in the troposphere include hydrogen chloride (HCl), carbon monoxide (CO), chlorine (Cl2), formyl chloride (HCOCl), carbonyl chloride (COCl2), and hydrogen peroxide (H2O2). Among them, COCl2 (also called phosgene) is a powerful irritating gas, which is easily hydrolyzed or thermally decomposed to form hydrogen chloride. PMID:29051455

  4. Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts.

    Science.gov (United States)

    Tsai, Wen-Tien

    2017-09-21

    Among the halogenated hydrocarbons, chloromethanes (i.e., methyl chloride, CH₃Cl; methylene chloride, CH₂Cl₂; chloroform, CHCl₃; and carbon tetrachloride, CCl₄) play a vital role due to their extensive uses as solvents and chemical intermediates. This article aims to review their main chemical/physical properties and commercial/industrial uses, as well as the environment and health hazards posed by them and their toxic decomposition products. The environmental properties (including atmospheric lifetime, radiative efficiency, ozone depletion potential, global warming potential, photochemical ozone creation potential, and surface mixing ratio) of these chlorinated methanes are also reviewed. In addition, this paper further discusses their atmospheric fates and human health implications because they are apt to reside in the lower atmosphere when released into the environment. According to the atmospheric degradation mechanism, their toxic degradation products in the troposphere include hydrogen chloride (HCl), carbon monoxide (CO), chlorine (Cl₂), formyl chloride (HCOCl), carbonyl chloride (COCl₂), and hydrogen peroxide (H₂O₂). Among them, COCl₂ (also called phosgene) is a powerful irritating gas, which is easily hydrolyzed or thermally decomposed to form hydrogen chloride.

  5. Atmospheric Observations and Models of Greenhouse Gas Emissions in Urban Environments

    OpenAIRE

    McKain, Kathryn

    2015-01-01

    Greenhouse gas emission magnitudes, trends, and source contributions are highly uncertain, particularly at sub-national scales. As the world becomes increasingly urbanized, one potential strategy for reducing these uncertainties is to focus atmospheric greenhouse gas measurements in urban areas, where a multitude of emission processes occur, imposing a strong and persistent gradient in the local atmosphere, and contributing a significant fraction of global anthropogenic greenhouse gas emissio...

  6. Atmospheric contamination

    International Nuclear Information System (INIS)

    Gruetter, Juerg

    1997-01-01

    It is about the levels of contamination in center America, the population's perception on the problem, effects of the atmospheric contamination, effects in the environment, causes of the atmospheric contamination, possibilities to reduce the atmospheric contamination and list of Roeco Swisscontac in atmospheric contamination

  7. Space Based Measurements for Atmospheric Carbon Dioxide: a New Tool for Monitoring Our Environment

    Science.gov (United States)

    Crisp, David

    2015-01-01

    Fossil fuel combustion, deforestation, and other human activities are now adding almost 40 billion tons of carbon dioxide (CO2) to the atmosphere each year. Interestingly, as these emissions have increased over time, natural "sinks" in land biosphere and oceans have absorbed roughly half of this CO2, reducing the rate of atmospheric buildup by a half. Measurements of the increasing acidity (pH) of seawater indicate that the ocean absorbs one quarter of this CO2. Another quarter is apparently being absorbed by the land biosphere, but the identity and location of these natural land CO2 "sinks" are still unknown. The existing ground-based greenhouse gas monitoring network provides an accurate record of the atmospheric buildup, but still does not have the spatial resolution or coverage needed to identify or quantify CO2 sources and sinks.

  8. Improving Fermi Orbit Determination and Prediction in an Uncertain Atmospheric Drag Environment

    Science.gov (United States)

    Vavrina, Matthew A.; Newman, Clark P.; Slojkowski, Steven E.; Carpenter, J. Russell

    2014-01-01

    Orbit determination and prediction of the Fermi Gamma-ray Space Telescope trajectory is strongly impacted by the unpredictability and variability of atmospheric density and the spacecraft's ballistic coefficient. Operationally, Global Positioning System point solutions are processed with an extended Kalman filter for orbit determination, and predictions are generated for conjunction assessment with secondary objects. When these predictions are compared to Joint Space Operations Center radar-based solutions, the close approach distance between the two predictions can greatly differ ahead of the conjunction. This work explores strategies for improving prediction accuracy and helps to explain the prediction disparities. Namely, a tuning analysis is performed to determine atmospheric drag modeling and filter parameters that can improve orbit determination as well as prediction accuracy. A 45% improvement in three-day prediction accuracy is realized by tuning the ballistic coefficient and atmospheric density stochastic models, measurement frequency, and other modeling and filter parameters.

  9. Measurement and analysis of ambient atmospheric particulate matter in urban and remote environments

    Science.gov (United States)

    Hagler, Gayle S. W.

    Atmospheric particulate matter pollution is a challenging environmental concern in both urban and remote locations worldwide. It is intrinsically difficult to control, given numerous anthropogenic and natural sources (e.g. fossil fuel combustion, biomass burning, dust, and seaspray) and atmospheric transport up to thousands of kilometers after production. In urban regions, fine particulate matter (particles with diameters under 2.5 mum) is of special concern for its ability to penetrate the human respiratory system and threaten cardiopulmonary health. A second major impact area is climate, with particulate matter altering Earth's radiative balance through scattering and absorbing solar radiation, modifying cloud properties, and reducing surface reflectivity after deposition in snow-covered regions. While atmospheric particulate matter has been generally well-characterized in populated areas of developed countries, particulate pollution in developing nations and remote regions is relatively unexplored. This thesis characterizes atmospheric particulate matter in locations that represent the extreme ends of the spectrum in terms of air pollution-the rapidly-developing and heavily populated Pearl River Delta Region of China, the pristine and climate-sensitive Greenland Ice Sheet, and a remote site in the Colorado Rocky Mountains. In China, fine particles were studied through a year-long field campaign at seven sites surrounding the Pearl River Delta. Fine particulate matter was analyzed for chemical composition, regional variation, and meteorological impacts. On the Greenland Ice Sheet and in the Colorado Rocky Mountains, the carbonaceous fraction (organic and elemental carbon) of particulate matter was studied in the atmosphere and snow pack. Analyses included quantifying particulate chemical and optical properties, assessing atmospheric transport, and evaluating post-depositional processing of carbonaceous species in snow.

  10. Comparison of atmosphere/aquatic environment concentration ratio of volatile chlorinated hydrocarbons between temperate regions and Antarctica.

    Science.gov (United States)

    Zoccolillo, Lelio; Amendola, Luca; Insogna, Susanna

    2009-09-01

    For the purpose of understanding the transport and deposition mechanisms and the air-water distribution of some volatile chlorinated hydrocarbons (VCHCs), their atmosphere/aquatic environment concentration ratio was evaluated. In addition, for the purpose of differentiating VCHC behaviour in a temperate climate from its behaviour in a polar climate, the atmosphere/aquatic environment concentration ratio evaluated in matrices from temperate zones was compared with the concentration ratio evaluated in Antarctic matrices. In order to perform air samplings also at rigid Antarctic temperatures, the sampling apparatus, consisting of a diaphragm pump and canisters, was suitably modified. Chloroform, 1,1,1-trichloroethane, tetrachloromethane, 1,1,2-trichloroethylene and tetrachloroethylene were measured in air, water and snow using specific techniques composed of a purpose-made cryofocusing-trap-injector (for air samples) and a modified purge-and-trap injector (for aqueous samples) coupled to a gas chromatograph with mass spectrometric detection operating in selected ion monitoring mode. The VCHCs were retrieved in all the investigated matrices, both Italian and Antarctic, with concentrations varying from tens to thousands of ng m(-3) in air and from digits to hundreds of ng kg(-1) in water and snow. The atmosphere/aquatic environment concentration ratios were always found to be lower than 1. In particular, the Italian air/water concentration ratios were smaller than the Antarctic ones, by reason of the higher atmospheric photochemical activity in temperate zones. On the other hand, the Antarctic air/snow concentration ratios proved to be largely in favour of snow with respect to the Italian ratios, thus corroborating the hypothesis of a more efficient VCHC deposition mechanism and accumulation on Antarctic snow.

  11. Anoxic atmospheres on Mars driven by volcanism: Implications for past environments and life

    Science.gov (United States)

    Sholes, Steven F.; Smith, Megan L.; Claire, Mark W.; Zahnle, Kevin J.; Catling, David C.

    2017-07-01

    Mars today has no active volcanism and its atmosphere is oxidizing, dominated by the photochemistry of CO2 and H2O. Mars experienced widespread volcanism in the past and volcanic emissions should have included reducing gases, such as H2 and CO, as well as sulfur-bearing gases. Using a one-dimensional photochemical model, we consider whether plausible volcanic gas fluxes could have switched the redox-state of the past martian atmosphere to reducing conditions. In our model, the total quantity and proportions of volcanic gases depend on the water content, outgassing pressure, and oxygen fugacity of the source melt. We find that, with reasonable melt parameters, the past martian atmosphere (∼3.5 Gyr to present) could have easily reached reducing and anoxic conditions with modest levels of volcanism, >0.14 km3 yr-1, which are well within the range of estimates from thermal evolution models or photogeological studies. Counter-intuitively we also find that more reducing melts with lower oxygen fugacity require greater amounts of volcanism to switch a paleo-atmosphere from oxidizing to reducing. The reason is that sulfur is more stable in such melts and lower absolute fluxes of sulfur-bearing gases more than compensate for increases in the proportions of H2 and CO. These results imply that ancient Mars should have experienced periods with anoxic and reducing atmospheres even through the mid-Amazonian whenever volcanic outgassing was sustained at sufficient levels. Reducing anoxic conditions are potentially conducive to the synthesis of prebiotic organic compounds, such as amino acids, and are therefore relevant to the possibility of life on Mars. Also, anoxic reducing conditions should have influenced the type of minerals that were formed on the surface or deposited from the atmosphere. We suggest looking for elemental polysulfur (S8) as a signature of past reducing atmospheres. Finally, our models allow us to estimate the amount of volcanically sourced atmospheric

  12. Anthropogenic atmospheric precipitation and quality of environment in Ivano-Frankivsk oblast

    OpenAIRE

    Ганжа, Дмитро Дмитрович; Ганжа, Дмитро Дмитрович

    2016-01-01

    It is studied anthropogenic atmospheric precipitation by the content of soluble salts, macroelements and dust in snow water. Total air pollution index was calculated by the measured parameters of precipitation. It was established statistical connections between total pollution index, on the one hand, and the population growth, mortality from tumors and vascular lesions at diseases of the circulatory system, on the other hand

  13. Atmospheric Electricity Hazards Analytical Model Development and Application. Volume I. Lightning Environment Modeling.

    Science.gov (United States)

    1981-08-01

    Library, Signet, 1964. Battan, L.J., Radar observation of the atmosphere, University of Chicago Press, Chicago, 1973. Barry, J.D., Ball lightning and...B.F.J., The flight of thunderbolts, 2nd (ed.), Oxford, Clarendon Press, 1964. Singer, S., The nature of ball lightning , Plenum Press, New York, 1971

  14. The Polluted Atmosphere of the White Dwarf NLTT 25792 and the Diversity of Circumstellar Environments

    Czech Academy of Sciences Publication Activity Database

    Vennes, Stephane; Kawka, Adela

    2013-01-01

    Roč. 779, č. 1 (2013), 70/1-70/10 ISSN 0004-637X R&D Projects: GA ČR GA13-14581S; GA ČR GAP209/12/0217 Institutional support: RVO:67985815 Keywords : stars * abundances * atmospheres Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 6.280, year: 2013

  15. A Controlled Environment System For Measuring Plant-Atmosphere Gas Exchange

    Science.gov (United States)

    James M. Brown

    1975-01-01

    Describes an inexpensive, efficient system for measuring plant-atmosphere gas exchange. Designed to measure transpiration from potted tree seedlings, it is readily adaptable for measuring other gas exchanges or gas exchange by plant parts. Light level, air and root temperature can be precisely controlled at minimum cost.

  16. Overview of the Atmosphere and Environment within Gale Crater on Mars

    Science.gov (United States)

    Vasavada, A. R.; Grotzinger, J. P.; Crisp, J. A.; Gomez-Elvira, J.; Mahaffy, P. R.; Webster, C. R.

    2012-12-01

    Curiosity's mission at Gale Crater places a number of highly capable atmospheric and environmental sensors within a dynamic setting: next to a 5-km mountain within a 150-km diameter impact crater whose floor is -4.5 km. Curiosity's scientific payload was chosen primarily to allow a geologic and geochemical investigation of Mars' environmental history and habitability, as preserved in the layered sediments on the crater floor and mound. Atmospheric and environmental sensors will contribute by measuring the bulk atmospheric chemical and isotopic composition, the flux of high-energy particle and ultraviolet radiation after modification by the atmosphere, and modern processes related to meteorology and climate over at least one Mars year. The Sample Analysis at Mars instrument will analyze the atmosphere with its mass spectrometer and tunable laser spectrometer. The former is capable of providing bulk composition and isotopic ratios of relevance to planetary evolution, such as nitrogen and noble gases. The latter is designed to acquire high-precision measurements of atmospheric species including CH4, CO2, and H2O, and key isotope ratios in H, C, and O. An important goal will be to compare CH4 abundance and time variability over the mission with the reported detections from the Mars Express orbiter and ground-based observations. The Radiation Assessment Detector (RAD) measures a broad spectrum of high-energy radiation incident at the surface, including secondary particles created via interactions of galactic cosmic rays and solar protons with Mars' atmospheric constituents. Curiosity's Rover Environmental Monitoring Station (REMS) carries six ultraviolet sensors, spanning 200-380 nm. For the first time, both the high-energy and ultraviolet radiation measured at the surface can be compared with measurements above the atmosphere, acquired by other platforms. Modern meteorology and the climatology of dust and water will be studied using the rover's cameras and REMS

  17. Source apportionment and environmental fate of lead chromates in atmospheric dust in arid environments.

    Science.gov (United States)

    Meza-Figueroa, Diana; González-Grijalva, Belem; Romero, Francisco; Ruiz, Joaquin; Pedroza-Montero, Martín; Rivero, Carlos Ibañez-Del; Acosta-Elías, Mónica; Ochoa-Landin, Lucas; Navarro-Espinoza, Sofía

    2018-03-07

    The environmental fate of lead derived from traffic paint has been poorly studied in developing countries, mainly in arid zones. For this purpose, a developing city located in the Sonoran desert (Hermosillo, Mexico), was chosen to conduct a study. In this paper the lead chromate (crocoite) sources in atmospheric dust were addressed using a combination of Raman microspectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and Pb isotope measurements. A high concentration of Pb and Cr as micro- and nanostructured pigments of crocoite is reported in yellow traffic paint (n=80), road dust (n=146), settled dust in roofs (n=21), and atmospheric dust (n=20) from a developing city located in the Sonoran Desert. 10 samples of peri-urban soils were collected for local geochemical background. The paint photodegradation and erosion of the asphaltic cover are enhanced by the climate, and the presence of the mineral crocoite (PbCrO 4 ) in road dust with an aerodynamic diameter ranging from 100nm to 2μm suggests its integration into the atmosphere by wind resuspension processes. A positive PbCr correlation (R 2 =0.977) was found for all studied samples, suggesting a common source. The Pb-isotope data show signatures in atmospheric dust as a product of the mixing of two end members: i) local soils and ii) crocoite crystals as pigments in paint. The presence of lead chromates in atmospheric dust has not been previously documented in Latin America, and it represents an unknown health risk to the exposed population because the identified size of crystals can reach the deepest part of lungs. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Atmospheric Corrosion Behavior and Mechanism of a Ni-Advanced Weathering Steel in Simulated Tropical Marine Environment

    Science.gov (United States)

    Wu, Wei; Zeng, Zhongping; Cheng, Xuequn; Li, Xiaogang; Liu, Bo

    2017-12-01

    Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner rust layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl-, was effectively separated in the outer rust layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

  19. A Description of the Framework of the Atmospheric Boundary Layer Environment (ABLE) Model

    Science.gov (United States)

    2012-09-01

    temperature, moisture, and scalars or pollutant transports. The model is based on a set of three-dimensional, prognostic, incompressible, Navier - Stocks ...transfer between the Earth’s surface and the atmosphere. We use a set of incompressible Navier - Stocks system equations with the Boussinesq...present (Stull 1989; Durran 2008). The first stage in the development is focused on the Reynolds Averaged Navier - Stocks (RANS) type model, and the second

  20. Photochemical reaction between triclosan and nitrous acid in the atmospheric aqueous environment

    Science.gov (United States)

    Ma, Jianzhong; Zhu, Chengzhu; Lu, Jun; Lei, Yu; Wang, Jizhong; Chen, Tianhu

    2017-05-01

    Nitrous acid (HONO) is an important tropospheric pollutant and a major source of hydroxyl radical in the atmospheric gas phase. However, studies on the role of HONO in atmospheric aqueous phase chemistry processes are relatively few. The present work investigated the photochemical reaction of HONO with triclosan (TCS), which is an emerging contaminant, using a combination of laser flash photolysis spectrometry and gas chromatography mass spectrometry. With these techniques, the reaction pathway of HONO with TCS was proposed by directly monitoring the transient species and detecting the stable products. ·OH was generated from the photodissociation of the HONO aqueous solution and attacked TCS molecules on different sites to produce the TCS-OH adducts with a second-order rate constant of 1.11 × 109 L mol-1 s-1. The ·OH added a C atom adjacent to the ether bond in the aromatic ring of TCS and self-decayed when the ether bond broke. The intermediates generated from the addition of ·OH to the benzene ring of the TCS molecular structure were immediately nitrated by HONO, which played a key role in the formation process of nitrocompounds. An atmospheric model suggests that the aqueous oxidation of TCS by ·OH is a major reaction at high liquid water concentrations, and the photolysis of TCS dominates under low-humidity conditions.

  1. Venus High Temperature Atmospheric Dropsonde and Extreme-Environment Seismometer (HADES)

    Science.gov (United States)

    Boll, Nathan J.; Salazar, Denise; Stelter, Christopher J.; Landis, Geoffrey A.; Colozza, Anthony J.

    2014-01-01

    The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration, however the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.

  2. Special Analysis: Atmospheric Dose Resulting from the Release of C14 from Reactor Moderator Deionizers in a Disposal Environment

    Energy Technology Data Exchange (ETDEWEB)

    Hiergesell, Robert A.; Swingle, Robert F.

    2005-08-18

    The proposed action of disposing of 52 moderator deionizer vessels within the ILV was evaluated in this SA. In particular, a detailed analysis of the release of {sup 14}C via the atmospheric pathway was conducted for these vessels since the major concern has been the nearly 20 Ci of {sup 14}C that is associated with each vessel. The more rigorous evaluation of the atmospheric pathway for {sup 14}C included incorporation of new information about the chemical availability of {sup 14}C when disposed in a grout/cement encapsulation environment, as will be the case in the ILV. This information was utilized to establish the source term for a 1-D numerical model to simulate the diffusion of {sup 14}CO{sub 2} from the ILV Waste Zone to the land surface. The results indicate a peak surface emanation rate from the entire ILV of 1.42E-08 Ci/yr with an associated dose of only 3.83E-05 mrem/yr to the Maximally Exposed Individual (MEI) at 100m. The fact that the atmospheric pathway exposure for {sup 14}C is controlled by chemical solubility limits for {sup 14}C between the solid waste, pore water and pore vapor within the disposal environment rather than the absolute inventory suggests that the establishment of specific facility limits is inappropriate. With the relaxation of the atmospheric pathway restriction, the groundwater pathway becomes the more restrictive in terms of disposing {sup 14}C or {sup 14}C{sub KB} within the ILV. Since the resin-based {sup 14}C of the 52 moderator deionizer vessels is highly similar to the {sup 14}C{sub KB} waste form, the inventory from the 52 deionizer vessels is compared against the groundwater limits for that waste form. The small groundwater pathway fraction (1.14E-05) calculated for the proposed inventory of the 52 moderator deionizer vessels indicates that the proposed action will have an insignificant impact with respect to possible exposures via the groundwater pathway. This investigation recommends that there be no ILV Atmospheric

  3. Special Analysis: Atmospheric Dose Resulting from the Release of C14 from Reactor Moderator Deionizers in a Disposal Environment

    International Nuclear Information System (INIS)

    Hiergesell, Robert A.; Swingle, Robert F.

    2005-01-01

    The proposed action of disposing of 52 moderator deionizer vessels within the ILV was evaluated in this SA. In particular, a detailed analysis of the release of 14 C via the atmospheric pathway was conducted for these vessels since the major concern has been the nearly 20 Ci of 14 C that is associated with each vessel. The more rigorous evaluation of the atmospheric pathway for 14 C included incorporation of new information about the chemical availability of 14 C when disposed in a grout/cement encapsulation environment, as will be the case in the ILV. This information was utilized to establish the source term for a 1-D numerical model to simulate the diffusion of 14 CO 2 from the ILV Waste Zone to the land surface. The results indicate a peak surface emanation rate from the entire ILV of 1.42E-08 Ci/yr with an associated dose of only 3.83E-05 mrem/yr to the Maximally Exposed Individual (MEI) at 100m. The fact that the atmospheric pathway exposure for 14 C is controlled by chemical solubility limits for 14 C between the solid waste, pore water and pore vapor within the disposal environment rather than the absolute inventory suggests that the establishment of specific facility limits is inappropriate. With the relaxation of the atmospheric pathway restriction, the groundwater pathway becomes the more restrictive in terms of disposing 14 C or 14 C KB within the ILV. Since the resin-based 14 C of the 52 moderator deionizer vessels is highly similar to the 14 C KB waste form, the inventory from the 52 deionizer vessels is compared against the groundwater limits for that waste form. The small groundwater pathway fraction (1.14E-05) calculated for the proposed inventory of the 52 moderator deionizer vessels indicates that the proposed action will have an insignificant impact with respect to possible exposures via the groundwater pathway. This investigation recommends that there be no ILV Atmospheric pathway limit for 14 C and 14 C KB . Further, in the absence of an

  4. Morphometric differences of Microgramma squamulosa (Kaulf. de la Sota (Polypodiaceae leaves in environments with distinct atmospheric air quality

    Directory of Open Access Journals (Sweden)

    LEDYANE D. ROCHA

    2014-09-01

    Full Text Available Plants growing in environments with different atmospheric conditions may present changes in the morphometric parameters of their leaves. Microgramma squamulosa (Kaulf. de la Sota is a neotropical epiphytic fern found in impacted environments. The aims of this study were to quantitatively compare structural characteristics of leaves in areas with different air quality conditions, and to identify morphometric parameters that are potential indicators of the effects of pollution on these plants. Fertile and sterile leaves growing on isolated trees were collected from an urban (Estância Velha and a rural (Novo Hamburgo environment, in Rio Grande do Sul, Brazil. For each leaf type, macroscopic and microscopic analyses were performed on 192 samples collected in each environment. The sterile and fertile leaves showed significantly greater thickness of the midrib and greater vascular bundle and leaf blade areas in the rural environment, which is characterized by less air pollution. The thickness of the hypodermis and the stomatal density of the fertile leaves were greater in the urban area, which is characterized by more air pollution. Based on the fact that significant changes were found in the parameters of both types of leaves, which could possibly be related to air pollutants, M. squamulosa may be a potential bioindicator.

  5. Transport of tritium contamination to the atmosphere in an arid environment

    Science.gov (United States)

    Garcia, C. Amanda; Andraski, Brian J.; Johnson, Michael J.; Stonestrom, David A.; Michel, Robert L.; Cooper, C.A.; Wheatcraft, S.W.

    2009-01-01

    Soil–plant–atmosphere interactions strongly influence water movement in desert unsaturated zones, but little is known about how such interactions affect atmospheric release of subsurface water-borne contaminants. This 2-yr study, performed at the U.S. Geological Survey's Amargosa Desert Research Site in southern Nevada, quantified the magnitude and spatiotemporal variability of tritium (3H) transport from the shallow unsaturated zone to the atmosphere adjacent to a low-level radioactive waste (LLRW) facility. Tritium fluxes were calculated as the product of 3H concentrations in water vapor and respective evaporation and transpiration water-vapor fluxes. Quarterly measured 3H concentrations in soil water vapor and in leaf water of the dominant creosote-bush [Larrea tridentata (DC.) Coville] were spatially extrapolated and temporally interpolated to develop daily maps of contamination across the 0.76-km2 study area. Maximum plant and root-zone soil concentrations (4200 and 8700 Bq L−1, respectively) were measured 25 m from the LLRW facility boundary. Continuous evaporation was estimated using a Priestley–Taylor model and transpiration was computed as the difference between measured eddy-covariance evapotranspiration and estimated evaporation. The mean evaporation/transpiration ratio was 3:1. Tritium released from the study area ranged from 0.12 to 12 μg d−1 and totaled 1.5 mg (8.2 × 1010 Bq) over 2 yr. Tritium flux variability was driven spatially by proximity to 3H source areas and temporally by changes in 3H concentrations and in the partitioning between evaporation and transpiration. Evapotranspiration removed and limited penetration of precipitation beneath native vegetation and fostered upward movement and release of 3H from below the root zone.

  6. Atmospheric Corrosion Investigation in Industrial, Marine and Rural Environments in South-East Brazil

    International Nuclear Information System (INIS)

    Souza, Paulo A. de; Macedo, M. C. S. de; Queiroz, R. S. de; Klingelhoefer, G.

    2002-01-01

    ASTM 283-C, AISI 304 and 316-L steel specimens (called coupons) were exposed in marine, industrial and rural area(s) for different periods ranging between 1-12 months, in four different season campaigns. The corrosion rate was determined by chemical loss measurements. Rust characterization was performed by XRD, SEM, optical, and Moessbauer spectroscopy (in transmission and backscattering geometry). Superparamagnetic maghemite and goethite were found as corrosion products. Magnetic goethite and feroxyhite decrease with time of exposure. Lepidochrosite is detected and its intensity increase with the atmospheric exposure time. The results obtained from XRD and Moessbauer are in good agreement.

  7. Impact of urban atmospheric environment on hospital admissions in the elderly

    Directory of Open Access Journals (Sweden)

    Edelci Nunes da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To analyze the impact of intra-urban atmospheric conditions on circulatory and respiratory diseases in elder adults. METHODS: Cross-sectional study based on data from 33,212 hospital admissions in adults over 60 years in the city of São Paulo, southeastern Brazil, from 2003 to 2007. The association between atmospheric variables from Congonhas airport and bioclimatic index, Physiological Equivalent Temperature, was analyzed according to the district's socioenvironmental profile. Descriptive statistical analysis and regression models were used. RESULTS: There was an increase in hospital admissions due to circulatory diseases as average and lowest temperatures decreased. The likelihood of being admitted to the hospital increased by 12% with 1ºC decrease in the bioclimatic index and with 1ºC increase in the highest temperatures in the group with lower socioenvironmental conditions. The risk of admission due to respiratory diseases increased with inadequate air quality in districts with higher socioenvironmental conditions. CONCLUSIONS: The associations between morbidity and climate variables and the comfort index varied in different groups and diseases. Lower and higher temperatures increased the risk of hospital admission in the elderly. Districts with lower socioenvironmental conditions showed greater adverse health impacts.

  8. ATMOSPHERIC DYNAMICS OF AIR POLLUTION DISPERSION AND SUSTAINABLE ENVIRONMENT IN JOS-NIGERIA

    Directory of Open Access Journals (Sweden)

    Moses Eterigho Emetere

    2017-01-01

    Full Text Available The basic properties of chlorine were used to determine the dis persion patterns of the recent Jos explosion. The dynamic aerosols content model was us ed to affirm the eight kinds of dispersion patterns discussed in this text. The locati on of the victims showed that the dispersion at Jos was either linear or polynomial disp ersion. The dispersions are influenced by atmospheric ventilation, stagnation and recir culation. The last chlorine gas explosion follows the linear or polynomial dispers ion because of the current state of aerosol loadings in Jos. The aftermath effect of this kind of dispersion may be more threatening than the initial danger due to the chem ical formation of more dangerous compounds. The atmosphe ric conditions for the formati on of toxic compound were investigated using twelve years MERRA satellite o bservation. The degree of freedom of methane, carbon oxide and ozone was nearly uniform for the past five years. This means the next five years or more may be threa tening for life forms within the region. The installation of gas tracers within major locations in Jos was suggested to monitor the formation of dioxins in the atmosphere.

  9. Substitution of Organic Solvents - a Way to improve Working Environment and reduce Emissions to the Atmosphere

    DEFF Research Database (Denmark)

    Jacobsen, Thomas

    1996-01-01

    Often there is a conflict between considerations regarding the working environment, and considerations regarding the environment, locally and globally, outside the company. When processes involving use of volatile, organic solvents are closely analyzed, it may in many cases be possible to change...... the process in order to omit the solvents or to use water-based products. In cases, where a change to water-based is not evident, improvements can be reached by using non-volatile, low-toxic products, typically esters of fatty acids from vegetable oils. In offset printing a drastic reduction of use of organic...

  10. The influence of bubble populations generated under windy conditions on the blue-green light transmission in the upper ocean: An exploratory approach

    Science.gov (United States)

    Wang, Chengan; Tan, Jianyu; Lai, Qingzhi

    2016-12-01

    The “blue-green window” in the ocean plays an important role in functions such as communication between vessels, underwater target identification, and remote sensing. In this study, the transmission process of blue-green light in the upper ocean is analyzed numerically using the Monte Carlo method. First, the effect of total number of photons on the numerical results is evaluated, and the most favorable number is chosen to ensure accuracy without excessive costs for calculation. Then, the physical and mathematical models are constructed. The rough sea surface is generated under windy conditions and the transmission signals are measured in the far field. Therefore, it can be conceptualized as a 1D slab with a rough boundary surface. Under windy conditions, these bubbles form layers that are horizontally homogeneous and decay exponentially with depth under the influence of gravity. The effects of bubble populations on the process of blue-green light transmission at different wind speeds, wavelengths, angle of incidence and chlorophyll-a concentrations are studied for both air-incident and water-incident cases. The results of this study indicate that the transmission process of blue-green light is significantly influenced by bubbles under high wind-speed conditions.

  11. Atmospheric versus biological sources of polycyclic aromatic hydrocarbons (PAHs) in a tropical rain forest environment.

    Science.gov (United States)

    Krauss, Martin; Wilcke, Wolfgang; Martius, Christopher; Bandeira, Adelmar G; Garcia, Marcos V B; Amelung, Wulf

    2005-05-01

    To distinguish between pyrogenic and biological sources of PAHs in a tropical rain forest near Manaus, Brazil, we determined the concentrations of 21 PAHs in leaves, bark, twigs, and stem wood of forest trees, dead wood, mineral topsoil, litter layer, air, and Nasutitermes termite nest compartments. Naphthalene (NAPH) was the most abundant PAH with concentrations of 35 ng m(-3) in air (>85% of the sum of 21PAHs concentration), up to 1000 microg kg(-1) in plants (>90%), 477 microg kg(-1) in litter (>90%), 32 microg kg(-1) in topsoil (>90%), and 160 microg kg(-1) (>55%) in termite nests. In plants, the concentrations of PAHs in general decreased in the order leaves > bark > twigs > stem wood. The concentrations of most low-molecular weight PAHs in leaves and bark were near equilibrium with air, but those of NAPH were up to 50 times higher. Thus, the atmosphere seemed to be the major source of all PAHs in plants except for NAPH. Additionally, phenanthrene (PHEN) had elevated concentrations in bark and twigs of Vismia cayennensis trees (12-60 microg kg(-1)), which might have produced PHEN. In the mineral soil, perylene (PERY) was more abundant than in the litter layer, probably because of in situ biological production. Nasutitermes nests had the highest concentrations of most PAHs in exterior compartments (on average 8 and 15 microg kg(-1) compared to atmosphere controls the concentrations of most PAHs. However, the occurrence of NAPH, PHEN, and PERY in plants, termite nests, and soils at elevated concentrations supports the assumption of their biological origin.

  12. Atmospheric versus biological sources of polycyclic aromatic hydrocarbons (PAHs) in a tropical rain forest environment

    International Nuclear Information System (INIS)

    Krauss, Martin; Wilcke, Wolfgang; Martius, Christopher; Bandeira, Adelmar G.; Garcia, Marcos V.B.; Amelung, Wulf

    2005-01-01

    To distinguish between pyrogenic and biological sources of PAHs in a tropical rain forest near Manaus, Brazil, we determined the concentrations of 21 PAHs in leaves, bark, twigs, and stem wood of forest trees, dead wood, mineral topsoil, litter layer, air, and Nasutitermes termite nest compartments. Naphthalene (NAPH) was the most abundant PAH with concentrations of 35 ng m -3 in air (>85% of the Σ21PAHs concentration), up to 1000 μg kg -1 in plants (>90%), 477 μg kg -1 in litter (>90%), 32 μg kg -1 in topsoil (>90%), and 160 μg kg -1 (>55%) in termite nests. In plants, the concentrations of PAHs in general decreased in the order leaves > bark > twigs > stem wood. The concentrations of most low-molecular weight PAHs in leaves and bark were near equilibrium with air, but those of NAPH were up to 50 times higher. Thus, the atmosphere seemed to be the major source of all PAHs in plants except for NAPH. Additionally, phenanthrene (PHEN) had elevated concentrations in bark and twigs of Vismia cayennensis trees (12-60 μg kg -1 ), which might have produced PHEN. In the mineral soil, perylene (PERY) was more abundant than in the litter layer, probably because of in situ biological production. Nasutitermes nests had the highest concentrations of most PAHs in exterior compartments (on average 8 and 15 μg kg -1 compared to -1 in interior parts) and high PERY concentrations in all compartments (12-86 μg kg -1 ), indicating an in situ production of PERY in the nests. Our results demonstrate that the deposition of pyrolytic PAHs from the atmosphere controls the concentrations of most PAHs. However, the occurrence of NAPH, PHEN, and PERY in plants, termite nests, and soils at elevated concentrations supports the assumption of their biological origin. - Evidence of non-pyrolytic, biogenic production of PAHs is provided

  13. Transpiration of shrub species, Alnus firma under changing atmospheric environments in montane area, Japan

    Science.gov (United States)

    Miyazawa, Y.; Maruyama, A.; Inoue, A.

    2014-12-01

    In the large caldera of Mt. Aso in Japan, grasslands have been traditionally managed by the farmers. Due to changes in the social structure of the region, a large area of the grassland has been abandoned and was invaded by the shrubs with different hydrological and ecophysiological traits. Ecophysiological traits and their responses to seasonally changing environments are fundamental to project the transpiration rates under changing air and soil water environments, but less is understood. We measured the tree- and leaf-level ecophysiological traits of a shrub, Alnus firma in montane region where both rainfall and soil water content drastically changes seasonally. Sap flux reached the annual peak in evaporative summer (July-August) both in 2013 and 2014, although the duration was limited within a short period due to the prolonged rainy season before summer (2014) and rapid decrease in the air vapor pressure deficit (D) in late summer. Leaf ecophysiological traits in close relationship with gas exchange showed modest seasonal changes and the values were kept at relatively high levels typical in plants with nitrogen fixation under nutrient-poor environments. Stomatal conductance, which was measured at leaf-level measurements and sap flux measurements, showed responses to D, which coincided with the theoretical response for isohydric leaves. A multilayer model, which estimates stand-level transpiration by scaling up the leaf-level data, successfully captured the temporal trends in sap flux, suggesting that major processes were incorporated. Thus, ecophysiological traits of A. firma were characterized by the absence of responses to seasonally changing environments and the transpiration rate was the function of the interannually variable environmental conditions.

  14. EntrySat: A 3U CubeStat to study the reentry atmospheric environment

    Science.gov (United States)

    Anthony, Sournac; Raphael, Garcia; David, Mimoun; Jeremie, Chaix

    2016-04-01

    ISAE France Entrysat has for main scientific objective the study of uncontrolled atmospheric re-entry. This project, is developed by ISAE in collaboration with ONERA and University of Toulouse, is funded by CNES, in the overall frame of the QB50 project. This nano-satellite is a 3U Cubesat measuring 34*10*10 cm3, similar to secondary debris produced during the break up of a spacecraft. EntrySat will collect the external and internal temperatures, pressure, heat flux, attitude variations and drag force of the satellite between ≈150 and 90 km before its destruction in the atmosphere, and transmit them during the re-entry using the IRIDIUM satellite network. The result will be compared with the computations of MUSIC/FAST, a new 6-degree of freedom code developed by ONERA to predict the trajectory of space debris. In order to fulfil the scientific objectives, the satellite will acquire 18 re-entry sensors signals, convert them and compress them, thanks to an electronic board developed by ISAE students in cooperation with EREMS. In order to transmit these data every second during the re-entry phase, the satellite will use an IRIDIUM connection. In order to keep a stable enough attitudes during this phase, a simple attitude orbit and control system using magnetotorquers and an inertial measurement unit (IMU) is developed at ISAE by students. A commercial GPS board is also integrated in the satellite into Entry Sat to determine its position and velocity which are necessary during the re-entry phase. This GPS will also be used to synchronize the on-board clock with the real-time UTC data. During the orbital phase (≈2 year) EntrySat measurements will be recorded transmitted through a more classical "UHF/VHF" connection. Preference for presentation: Poster Most suitable session: Author for correspondence: Dr Raphael F. Garcia ISAE 10, ave E. Belin, 31400 Toulouse, France Raphael.GARCIA@isae.fr +33 5 61 33 81 14

  15. Atmospheric Nitrogen Deposition at Two Sites in an Arid Environment of Central Asia.

    Science.gov (United States)

    Li, Kaihui; Liu, Xuejun; Song, Wei; Chang, Yunhua; Hu, Yukun; Tian, Changyan

    2013-01-01

    Arid areas play a significant role in the global nitrogen cycle. Dry and wet deposition of inorganic nitrogen (N) species were monitored at one urban (SDS) and one suburban (TFS) site at Urumqi in a semi-arid region of central Asia. Atmospheric concentrations of NH3, NO2, HNO3, particulate ammonium and nitrate (pNH4 (+) and pNO3 (-)) concentrations and NH4-N and NO3-N concentrations in precipitation showed large monthly variations and averaged 7.1, 26.6, 2.4, 6.6, 2.7 µg N m(-3) and 1.3, 1.0 mg N L(-1) at both SDS and TFS. Nitrogen dry deposition fluxes were 40.7 and 36.0 kg N ha(-1) yr(-1) while wet deposition of N fluxes were 6.0 and 8.8 kg N ha(-1) yr(-1) at SDS and TFS, respectively. Total N deposition averaged 45.8 kg N ha(-1) yr(-1)at both sites. Our results indicate that N dry deposition has been a major part of total N deposition (83.8% on average) in an arid region of central Asia. Such high N deposition implies heavy environmental pollution and an important nutrient resource in arid regions.

  16. Testing FSO WDM communication system in simulation software optiwave OptiSystem in different atmospheric environments

    Science.gov (United States)

    Vanderka, Ales; Hajek, Lukas; Bednarek, Lukas; Latal, Jan; Vitasek, Jan; Hejduk, Stanislav; Vasinek, Vladimir

    2016-09-01

    In this article the author's team deals with using Wavelength Division Multiplexing (WDM) for Free Space Optical (FSO) Communications. In FSO communication occurs due to the influence of atmospheric effect (attenuation, and fluctuation of the received power signal, influence turbulence) and the WDM channel suffers from interchannel crosstalk. There is considered only the one direction. The behavior FSO link was tested for one or eight channels. Here we will be dealing with modulation schemes OOK (On-Off keying), QAM (Quadrature Amplitude Modulation) and Subcarrier Intensity Modulation (SIM) based on a BPSK (Binary Phase Shift Keying). Simulation software OptiSystem 14 was used for tasting. For simulation some parameters were set according to real FSO link such as the datarate 1.25 Gbps, link range 1.4 km. Simulated FSO link used wavelength of 1550 nm with 0.8 nm spacing. There is obtained the influence of crosstalk and modulation format for the BER, depending on the amount of turbulence in the propagation medium.

  17. Demonstrating the Operational Value of Atmospheric Infrared Sounder (AIRS) Retrieved Profiles in the Pre-Convective Environment

    Science.gov (United States)

    Kozlowski, Danielle M.; Zavodsky, T.; Jedloved, Gary J.

    2011-01-01

    The Short-term Prediction Research and Transition Center (SPoRT) is a collaborative partnership between NASA and operational forecasting partners, including a number of National Weather Service offices. SPoRT provides real-time NASA products and capabilities to its partners to address specific operational forecast challenges. One operational forecast challenge is forecasting convective weather in data-void regions such as large bodies of water (e.g. Gulf of Mexico). To address this forecast challenge, SPoRT produces a twice-daily three-dimensional analysis that blends a model first-guess from the Advanced Research Weather Research and Forecasting (WRF-ARW) model with retrieved profiles from the Atmospheric Infrared Sounder (AIRS) -- a hyperspectral sounding instrument aboard NASA's Aqua satellite that provides temperature and moisture profiles of the atmosphere. AIRS profiles are unique in that they give a three dimensional view of the atmosphere that is not available through the current rawinsonde network. AIRS has two overpass swaths across North America each day, one valid in the 0700-0900 UTC timeframe and the other in the 1900-2100 UTC timeframe. This is helpful because the rawinsonde network only has data from 0000 UTC and 1200 UTC at specific land-based locations. Comparing the AIRS analysis product with control analyses that include no AIRS data demonstrates the value of the retrieved profiles to situational awareness for the pre-convective (and convective) environment. In an attempt to verify that the AIRS analysis was a good representation of the vertical structure of the atmosphere, both the AIRS and control analyses are compared to a Rapid Update Cycle (RUC) analysis used by operational forecasters. Using guidance from operational forecasters, convective available potential energy (CAPE) was determined to be a vital variable in making convective forecasts and is used herein to demonstrate the utility of the AIRS profiles in changing the vertical

  18. Microorganisms and heavy metals associated with atmospheric deposition in a congested urban environment of a developing country: Sri Lanka.

    Science.gov (United States)

    Weerasundara, Lakshika; Amarasekara, R W K; Magana-Arachchi, D N; Ziyath, Abdul M; Karunaratne, D G G P; Goonetilleke, Ashantha; Vithanage, Meththika

    2017-04-15

    The presence of bacteria and heavy metals in atmospheric deposition were investigated in Kandy, Sri Lanka, which is a typical city in the developing world with significant traffic congestion. Atmospheric deposition samples were analyzed for Al, Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb which are heavy metals common to urban environments. Al and Fe were found in high concentrations due to the presence of natural sources, but may also be re-suspended by vehicular traffic. Relatively high concentrations of toxic metals such as Cr and Pb in dissolved form were also found. High Zn loads can be attributed to vehicular emissions and the wide use of Zn coated roofing materials. The metal loads in wet deposition showed higher concentrations compared to dry deposition. The metal concentrations among the different sampling sites significantly differ from each other depending on the traffic conditions. Industrial activities are not significant in Kandy City. Consequently, the traffic exerts high influence on heavy metal loadings. As part of the bacterial investigations, nine species of culturable bacteria, namely; Sphingomonas sp., Pseudomonas aeruginosa, Pseudomonas monteilii, Klebsiella pneumonia, Ochrobactrum intermedium, Leclercia adecarboxylata, Exiguobacterium sp., Bacillus pumilus and Kocuria kristinae, which are opportunistic pathogens, were identified. This is the first time Pseudomonas monteilii and Ochrobactrum intermedium has been reported from a country in Asia. The culturable fraction constituted ~0.01 to 10%. Pigmented bacteria and endospore forming bacteria were copious in the atmospheric depositions due to their capability to withstand harsh environmental conditions. The presence of pathogenic bacteria and heavy metals creates potential human and ecosystem health risk. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Horizontal Advection and Mixing of Pollutants in the Urban Atmospheric Environment

    Science.gov (United States)

    Magnusson, S. P.; Entekhabi, D.; Britter, R.; Norford, L.; Fernando, H. J.

    2013-12-01

    Although urban air quality and its impacts on the public health have long been studied, the increasing urbanization is raising concerns on how to better control and mitigate these health impacts. A necessary element in predicting exposure levels is fundamental understanding of flow and dispersion in urban canyons. The complex topology of building structures and roads requires the resolution of turbulence phenomena within urban canyons. The use of dense and low porosity construction material can lead to rapid heating in response to direct solar exposure due to large thermal mass. Hence thermal and buoyancy effects may be as important as mechanically-forced or shear-induced flows. In this study, the transport of pollutants within the urban environment, as well as the thermal and advection effects, are investigated. The focus is on the horizontal transport or the advection effects within the urban environment. With increased urbanization and larger and more spread cities, concern about how the upstream air quality situation can affect downstream areas. The study also examines the release and the dispersion of hazardous material. Due to the variety and complexity of urban areas around the world, the urban environment is simplified into adjacent two-dimensional urban street canyons. Pollutants are released inside each canyon. Computational Fluid Dynamics (CFD) simulations are applied to evaluate and quantify the flow rate out of each canyon and also the exchange of pollutants between the canyons. Imagine a row of ten adjacent urban street canyons of aspect ratio 1 with horizontal flow perpendicular to it as shown in the attached figure. C is the concentration of pollutants. The first digit indicates in what canyon the pollutant is released and the second digit indicates the location of that pollutant. For example, C3,4 is the concentration of pollutant released inside canyon 3 measured in canyon 4. The same amount of pollution is released inside the ten street canyons

  20. Contingency Trajectory Design for a Lunar Orbit Insertion Maneuver Failure by the Lunar Atmosphere Dust Environment Explorer (LADEE) Spacecraft

    Science.gov (United States)

    Genova, Anthony L.; Loucks, Michael; Carrico, John

    2014-01-01

    The purpose of this extended abstract is to present results from a failed lunar-orbit insertion (LOI) maneuver contingency analysis for the Lunar Atmosphere Dust Environment Explorer (LADEE) mission, managed and operated by NASA Ames Research Center in Moffett Field, CA. The LADEE spacecrafts nominal trajectory implemented multiple sub-lunar phasing orbits centered at Earth before eventually reaching the Moon (Fig. 1) where a critical LOI maneuver was to be performed [1,2,3]. If this LOI was missed, the LADEE spacecraft would be on an Earth-escape trajectory, bound for heliocentric space. Although a partial mission recovery is possible from a heliocentric orbit (to be discussed in the full paper), it was found that an escape-prevention maneuver could be performed several days after a hypothetical LOI-miss, allowing a return to the desired science orbit around the Moon without leaving the Earths sphere-of-influence (SOI).

  1. Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment

    International Nuclear Information System (INIS)

    Mishra, Nitika; Ayoko, Godwin A.; Morawska, Lidia

    2016-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis – Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. - Highlights: • PAHs represent a major group of outdoor air pollutants. • Concentration levels of PAHS in urban schools ranged from 1.2 to 38 ng/m 3 . • PCA–APCS technique used to identify sources of PAHs and their contributions. • Vehicular emissions (56%) were found to be the prominent sources of PAHs.

  2. Quantitative Analysis of Major Factors Affecting Black Carbon Transport and Concentrations in the Unique Atmospheric Structures of Urban Environment

    Science.gov (United States)

    Liang, Marissa Shuang

    combined contribution from both traffic and atmospheric circulation accounted for observed spatiotemporal variability in PM2.5 concentrations. Based on these experimental and quantitative analyses, a three-dimensional model is proposed for contaminant's transport in highly urbanized Cincinnati region. Furthermore this dissertation explored implications on roadside pollutant evaluation, and on the risk analysis of future fuel substitution using biodiesel. The Gaussian-type models are poor in determining the effective emission factor particularly under nocturnal thermal inversion for which the effective emission factor is a function of lapse rate in the morning. The Gaussian models are applicable in daytime after the breakdown of thermal inversion. Lastly, among three types of fuels examined, the proposed butanol-added biodiesel-diesel blend (D80B15Bu5) yielded a good compromise between black carbon and NOx emissions while maintaining proper combustion properties. It is also found that the emission contained less black carbon and had higher organic carbon (OC) and elemental (EC) ratio than tested petroleum diesel. As demonstrated in other parts of this study, the OC-enriched emission will likely affect the black carbon occurrence and PM concentrations in the urban environments. Overall, it is suggested that urban formation and biofuel usage define the environmental impacts of black carbon, and are the focus for climate change mitigation and adaptation.

  3. Hygroscopic properties of submicrometer atmospheric aerosol particles measured with H-TDMA instruments in various environments-a review

    Science.gov (United States)

    Swietlicki, E.; Hansson, H.-C.; Hämeri, K.; Svenningsson, B.; Massling, A.; McFiggans, G.; McMurry, P. H.; Petäjä, T.; Tunved, P.; Gysel, M.; Topping, D.; Weingartner, E.; Baltensperger, U.; Rissler, J.; Wiedensohler, A.; Kulmala, M.

    2008-07-01

    The hygroscopic properties play a vital role for the direct and indirect effects of aerosols on climate, as well as the health effects of particulate matter (PM) by modifying the deposition pattern of inhaled particles in the humid human respiratory tract. Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA) instruments have been used in field campaigns in various environments globally over the last 25 yr to determine the water uptake on submicrometre particles at subsaturated conditions. These investigations have yielded valuable and comprehensive information regarding the particle hygroscopic properties of the atmospheric aerosol, including state of mixing. These properties determine the equilibrium particle size at ambient relative humidities and have successfully been used to calculate the activation of particles at water vapour supersaturation. This paper summarizes the existing published H-TDMA results on the size-resolved submicrometre aerosol particle hygroscopic properties obtained from ground-based measurements at multiple marine, rural, urban and free tropospheric measurement sites. The data is classified into groups of hygroscopic growth indicating the external mixture, and providing clues to the sources and processes controlling the aerosol. An evaluation is given on how different chemical and physical properties affect the hygroscopic growth.

  4. Natural Atmospheric Environment Model Development for the National Aeronautics and Space Administration's Second Generation Reusable Launch Vehicle

    Science.gov (United States)

    Roberts, Barry C.; Leahy, Frank; Overbey, Glenn; Batts, Glen W.; Parker, Nelson (Technical Monitor)

    2002-01-01

    The National Aeronautics and Space Administration (NASA) recently began development of a new reusable launch vehicle. The program office is located at Marshall Space Flight Center (MSFC) and is called the Second Generation Reusable Launch Vehicle (2GRLV). The purpose of the program is to improve upon the safety and reliability of the first generation reusable launch vehicle, the Space Shuttle. Specifically, the goals are to reduce the risk of crew loss to less than 1-in-10,000 missions and decreased costs by a factor of 10 to approximately $1,000 per pound of payload launched to low Earth orbit. The program is currently in the very early stages of development and many two-stage vehicle concepts will be evaluated. Risk reduction activities are also taking place. These activities include developing new technologies and advancing current technologies to be used by the vehicle. The Environments Group at MSFC is tasked by the 2GRLV Program to develop and maintain an extensive series of analytical tools and environmental databases which enable it to provide detailed atmospheric studies in support of structural, guidance, navigation and control, and operation of the 2GRLV.

  5. An analysis of long-term exposure pathways in the terrestrial environment following the release of radioactive materials to atmosphere

    International Nuclear Information System (INIS)

    Linsley, G.S.; Simmonds, J.R.

    1982-01-01

    Time-dependent models have been used to investigate the relative importance of the routes by which man may be exposed to radiation from deposited activity in the terrestrial environment. The pathways for exposure were ingestion of foodstuffs, external irradiation from ground deposits and inhalation of resuspended activity. The resulting doses due to each of these exposure pathways have been compared as a function of time after deposition for each of several nuclides known to be important in accidental releases; they are 90 Sr, 106 Ru, 131 I, 137 Cs and 239 Pu. The importance of the ingestion route of exposure is shown to vary markedly depending upon the season of the year in which radionuclides are deposited. The approach has been applied to the examination of the relative importance of terrestrial exposure routes following accidental releases to atmosphere from a light-water reactor. The dominant role of 134 Cs and 137 Cs beyond the period of the first year after the release in both ingestion and external irradiation exposure routes is evident in all sequences considered. (author)

  6. CROSS DRIVE: A Collaborative and Distributed Virtual Environment for Exploitation of Atmospherical and Geological Datasets of Mars

    Science.gov (United States)

    Cencetti, Michele

    2016-07-01

    European space exploration missions have produced huge data sets of potentially immense value for research as well as for planning and operating future missions. For instance, Mars Exploration programs comprise a series of missions with launches ranging from the past to beyond present, which are anticipated to produce exceptional volumes of data which provide prospects for research breakthroughs and advancing further activities in space. These collected data include a variety of information, such as imagery, topography, atmospheric, geochemical datasets and more, which has resulted in and still demands, databases, versatile visualisation tools and data reduction methods. Such rate of valuable data acquisition requires the scientists, researchers and computer scientists to coordinate their storage, processing and relevant tools to enable efficient data analysis. However, the current position is that expert teams from various disciplines, the databases and tools are fragmented, leaving little scope for unlocking its value through collaborative activities. The benefits of collaborative virtual environments have been implemented in various industrial fields allowing real-time multi-user collaborative work among people from different disciplines. Exploiting the benefits of advanced immersive virtual environments (IVE) has been recognized as an important interaction paradigm to facilitate future space exploration. The current work is mainly aimed towards the presentation of the preliminary results coming from the CROSS DRIVE project. This research received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 607177 and is mainly aimed towards the implementation of a distributed virtual workspace for collaborative scientific discovery, mission planning and operations. The purpose of the CROSS DRIVE project is to lay foundations of collaborative European workspaces for space science. It will demonstrate the feasibility and

  7. Possible use of EPDM in radioactive waste disposal: Long term low dose rate and short term high dose rate irradiation in aquatic and atmospheric environment

    Science.gov (United States)

    Hacıoğlu, Fırat; Özdemir, Tonguç; Çavdar, Seda; Usanmaz, Ali

    2013-02-01

    In this study, changes in the properties of ethylene propylene diene terpolymer (EPDM) irradiated with different dose rates in ambient atmosphere and aqueous environment were investigated. Irradiations were carried out both with low dose and high dose rate irradiation sources. EPDM samples which were differentiated from each other by peroxide type and 5-ethylidene 2-norbornene (ENB) contents were used. Long term low dose rate irradiations were carried out for the duration of up to 2.5 years (total dose of 1178 kGy) in two different irradiation environments. Dose rates (both high and low), irradiation environments (in aquatic and open to atmosphere), and peroxide types (aliphatic or aromatic) were the parameters studied. Characterization of irradiated EPDM samples were performed by hardness, compression, tensile, dynamic mechanical analysis (DMA), TGA-FTIR, ATR-FTIR, XRD and SEM tests. It was observed that the irradiation in water environment led to a lower degree of degradation when compared to that of irradiation open to atmosphere for the same irradiation dose. In addition, irradiation environment, peroxide type and dose rate had effects on the extent of change in the properties of EPDM. It was observed that EPDM is relatively radiation resistant and a candidate polymer for usage in radioactive waste management.

  8. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  9. A Survey of Precipitation-Induced Atmospheric Cold Pools over Oceans and Their Interactions with the Larger-Scale Environment

    Science.gov (United States)

    Zuidema, Paquita; Torri, Giuseppe; Muller, Caroline; Chandra, Arunchandra

    2017-11-01

    Pools of air cooled by partial rain evaporation span up to several hundreds of kilometers in nature and typically last less than 1 day, ultimately losing their identity to the large-scale flow. These fundamentally differ in character from the radiatively-driven dry pools defining convective aggregation. Advancement in remote sensing and in computer capabilities has promoted exploration of how precipitation-induced cold pool processes modify the convective spectrum and life cycle. This contribution surveys current understanding of such cold pools over the tropical and subtropical oceans. In shallow convection with low rain rates, the cold pools moisten, preserving the near-surface equivalent potential temperature or increasing it if the surface moisture fluxes cannot ventilate beyond the new surface layer; both conditions indicate downdraft origin air from within the boundary layer. When rain rates exceed ˜ 2 mm h^{-1}, convective-scale downdrafts can bring down drier air of lower equivalent potential temperature from above the boundary layer. The resulting density currents facilitate the lifting of locally thermodynamically favorable air and can impose an arc-shaped mesoscale cloud organization. This organization allows clouds capable of reaching 4-5 km within otherwise dry environments. These are more commonly observed in the northern hemisphere trade wind regime, where the flow to the intertropical convergence zone is unimpeded by the equator. Their near-surface air properties share much with those shown from cold pools sampled in the equatorial Indian Ocean. Cold pools are most effective at influencing the mesoscale organization when the atmosphere is moist in the lower free troposphere and dry above, suggesting an optimal range of water vapor paths. Outstanding questions on the relationship between cold pools, their accompanying moisture distribution and cloud cover are detailed further. Near-surface water vapor rings are documented in one model inside but

  10. Early Operations Flight Correlation of the Lunar Laser Communications Demonstration (LLCD) on the Lunar Atmosphere and Dust Environment Explorer (LADEE)

    Science.gov (United States)

    Peabody, Hume; Yang, Kan; Nguyen, Daniel; Cornwell, Donald

    2015-01-01

    The Lunar Atmosphere and Dust Environment Explorer (LADEE) mission launched on September 7, 2013 with a one month cruise before lunar insertion. The LADEE spacecraft is a power limited, octagonal, composite bus structure with solar panels on all eight sides with four vertical segments per side and 2 panels dedicated to instruments. One of these panels has the Lunar Laser Communications Demonstration (LLCD), which represents a furthering of the laser communications technology demonstration proved out by the Lunar Reconnaissance Orbiter (LRO). LLCD increases the bandwidth of communication to and from the moon with less mass and power than LROs technology demonstrator. The LLCD Modem and Controller boxes are mounted to an internal cruciform composite panel and have no dedicated radiator. The thermal design relies on power cycling of the boxes and radiation of waste heat to the inside of the panels, which then reject the heat when facing cold space. The LADEE mission includes a slow roll and numerous attitudes to accommodate the challenging thermal requirements for all the instruments on board. During the cruise phase, the internal Modem and Controller avionics for LLCD were warmer than predicted by more than modeling uncertainty would suggest. This caused concern that if the boxes were considerably warmer than expected while off, they would also be warmer when operating and could limit the operational time when in lunar orbit. The thermal group at Goddard Space Flight Center evaluated the models and design for these critical avionics for LLCD. Upon receipt of the spacecraft models and audit was performed and data was collected from the flight telemetry to perform a sanity check of the models and to correlate to flight where possible. This paper describes the efforts to correlate the model to flight data and to predict the thermal performance when in lunar orbit and presents some lessons learned.

  11. Assessment of atmospheric trace metal deposition in urban environments using direct and indirect measurement methodology and contributions from wet and dry depositions

    Science.gov (United States)

    Omrani, Mehrazin; Ruban, Véronique; Ruban, Gwenaël; Lamprea, Katerine

    2017-11-01

    Bulk Atmospheric Deposition (BAD), Wet Atmospheric Deposition (WAD) and Dry Atmospheric Deposition (DAD) were all measured within an urban residential area in Nantes (France) over a 9-month period (27 February - 10 December 2014). The objectives of this study were to compare 2 methods for measuring dry and wet atmospheric depositions in the urban environment (DAD and WAD: direct method; BAD and WAD: indirect one), and to characterize as well the variations and relative contributions of these depositions. Trace metals (As, Cd, Cr, Cu, Ni, Pt and V) were used to carry out these comparison and quantification. BAD was collected with two open polyethylene containers (72 × 54 × 21 cm), while WAD was collected by means of an automated rainwater collector and DAD was determined from both air measurements (recorded by an air sampler) and 7Be deposition velocities. The comparison based on a detailed evaluation of uncertainties showed a significant difference between the direct and indirect methods. Dry and wet depositions varied widely from one month to the next. Zn and Cu were the most abundant elements in both dry and wet depositions. The mean contribution of DAD to the bulk atmospheric deposition during this 9-month study was significant for Zn, Cu and V (about 25%) as well as for Pb (approx. 60%). For this relatively unpolluted urban residential catchment, the contribution of atmospheric deposition to global load at the catchment outlet was low, between 10% and 20% for Zn, Cu, V and Pb, 25% for Cr and about 30% for Ni. For other urban sites exhibiting high atmospheric pollution however, the atmospheric contribution to the global pollution load could be much greater. An accurate and representative estimation of DAD thus proves critical.

  12. An Atmosphere-based Method for Detection and Quantification of Methane Emisions from Natural Gas Infrastructure in an Urban Environment

    Science.gov (United States)

    McKain, K.; Down, A.; Raciti, S. M.; Budney, J.; Hutyra, L.; Floerchinger, C. R.; Herndon, S. C.; Nehrkorn, T.; Zahniser, M. S.; Sargent, M. R.; Jackson, R. B.; Phillips, N. G.; Wofsy, S. C.

    2015-12-01

    Methane emissions from the natural gas supply-chain are highly uncertain and can vary widely among components and processes. We present an atmosphere-based method for detecting and quantifying the area and time-averaged surface flux of methane from natural gas infrastructure, and its application to the case-study of Boston, Massachusetts. Continuous measurements of atmospheric methane at a network of stations, inside and outside the city, are used to quantify the atmospheric methane gradient due to emissions from the urban area. Simultaneous observations of atmospheric ethane, and data on the ethane and methane content of the pipeline gas flowing through the region, are used to trace the atmospheric methane enhancement to the natural gas source. An atmospheric transport model is used to quantitatively relate the observed methane enhancement to a surface flux from the whole urban region. We find that methane emissions from natural gas in the urban region over one year was equal to 2.7 ± 0.6 % of the natural gas delivered to the region. Our findings for Boston suggest natural-gas-consuming regions, generally, may be larger sources of methane to the atmosphere than is current estimated and represent areas of significant resource loss.

  13. Pacific Northwest Laboratory annual report for 1980 to the DOE Assistant Secretary for Environment. Part 3. Atmospheric sciences.

    Energy Technology Data Exchange (ETDEWEB)

    Elderkin, C.E.

    1981-02-01

    Separate absracts were prepared for the 15 sections of this progress report which is a description of atmospheric research at PNL organized in terms of the following energy technologies: coal, gas and oil; fission and fusion; and oil shale. (KRM)

  14. Pacific Northwest Laboratory annual report for 1980 to the DOE Assistant Secretary for Environment. Part 3. Atmospheric sciences

    International Nuclear Information System (INIS)

    Elderkin, C.E.

    1981-02-01

    Separate absracts were prepared for the 15 sections of this progress report which is a description of atmospheric research at PNL organized in terms of the following energy technologies: coal, gas and oil; fission and fusion; and oil shale

  15. Identification of Major Sources of Atmospheric NH3 in an Urban Environment in Northern China During Wintertime.

    Science.gov (United States)

    Teng, Xiaolin; Hu, Qingjing; Zhang, Leiming; Qi, Jiajia; Shi, Jinhui; Xie, Huan; Gao, Huiwang; Yao, Xiaohong

    2017-06-20

    To assess the relative contributions of traffic emission and other potential sources to high levels of atmospheric ammonia (NH 3 ) in urban areas in the wintertime, atmospheric NH 3 and related pollutants were measured at an urban site, ∼300 m from a major traffic road, in northern China in November and December 2015. Hourly average NH 3 varied from 0.3 to 10.8 ppb with an average of 2.4 ppb during the campaign. Contrary to the common perspective in literature, traffic emission was demonstrated to be a negligible contributor to atmospheric NH 3 . Atmospheric NH 3 correlated well with ambient water vapor during many time periods lasting from tens of hours to several days, implying NH 3 released from water evaporation is an important source. Emissions from local green space inside the urban areas were identified to significantly contribute to the observed atmospheric NH 3 during ∼60% of the sampling times. Evaporation of predeposited NH x through wet precipitation combined with emissions from local green space likely caused the spikes of atmospheric NH 3 mostly occurring 1-4 h after morning rush hours or after and during slight shower events. There are still ∼30% of the data samples with appreciable NH 3 level for which major contributors are yet to be identified.

  16. Observations of the UARS Particle Environment Monitor and computation of ionization rates in the middle and upper atmosphere during a geomagnetic storm

    Science.gov (United States)

    Sharber, J. R.; Frahm, R. A.; Winningham, J. D.; Biard, J. C.; Lummerzheim, D.; Rees, M. H.; Chenette, D. L.; Gaines, E. E.; Nightingale, R. W.; Imhof, W. L.

    1993-01-01

    In this paper we present observations made by the Particle Environment Monitor (PEM) instruments during the geomagnetic storm of 8-9 November, 1991. Ionization and energy deposition rates as functions of altitude in the middle and upper atmosphere by incident electrons and positive ions in the storm interval are computed. The suite of PEM instruments provides a systematic measurement of energetic particles and their associated X-rays over an energy range not fully covered by previous satellite missions.

  17. Environment

    Science.gov (United States)

    2005-01-01

    biodiversity. Consequently, the major environmental challenges facing us in the 21st century include: global climate change , energy, population and food...technological prowess, and security interests. Challenges Global Climate Change – Evidence shows that our environment and the global climate ... urbanization will continue to pressure the regional environment . Although most countries have environmental protection ministries or agencies, a lack of

  18. Response of vehicular lead to the presence of street dust in the atmospheric environment of major roads.

    Science.gov (United States)

    al-Chalabi, A S; Hawker, D

    1997-11-05

    Size fractionated particulate samples were collected from the roadside atmosphere of three major roads within the Brisbane Metropolitan area, using a high volume sampler fitted with an Anderson impactor. Street dusts were also sampled at these sites. Deposition samples were collected simultaneously with those of atmospheric particulates from periods with and without rainfall. All types of samples were quantitatively analysed for lead and various anions and cations. The pH and electrical conductivity for street dusts and deposition samples together with total solids content of deposition samples were also determined. Results showed that at sites where the process of street dust resuspension was at a minimum, the bromide-to-lead ratios were comparable to the reported ratio in uncombusted petrol. However, the relatively higher bromide-to-lead ratios observed at sites with active street dust resuspension indicate the existence of a process by which fine lead particulates are removed from the atmosphere by resuspended coarse dust particles.

  19. Investigation on the development of measurement techniques, the behavior in the environment and the estimation of internal radiation dose by inhalation for some typical atmospheric radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Hikaru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-06-01

    Radionuclides in surface atmosphere on the earth are {sup 222}Rn, {sup 220}Rn and their short lived progeny, {sup 7}Be, {sup 85}Kr, {sup 3}H, {sup 14}C, {sup 137}Cs, {sup 90}Sr and so on. In this paper, among them, {sup 222}Rn, their short lived progeny ({sup 218}Po, {sup 214}Pb, {sup 214}Bi, {sup 214}Po), {sup 7}Be, {sup 3}H, and {sup 90}Sr are focused on as follows based on the experimental and observed results, 1. Development of their measurement techniques, 2. Analysis of their variation of atmospheric concentration with time and places, 3. Analysis of their interaction characteristics with surface environment including plants, 4. Estimation of internal radiation doses by inhalation of them. (author). 228 refs.

  20. Observations of a Windy Star

    Science.gov (United States)

    Kohler, Susanna

    2017-06-01

    Hubble view of the Homunculus Nebula surrounding Eta Carinae [NASA Hubble Space Telescope/Jon Morse (University of Colorado)]The incredibly luminous massive star Eta Carinae has long posed a challenge for astronomers to model. New observations are now in so were our models correct?Dramatic TargetThe massive evolved star Eta Carinae, located 7,500 light-years away in the constellation Carina, is the most luminous star in the Milky Way. Eta Carinae has a quite a reputation for drama: it has been very unstable in the past, exhibiting repeated eruptions that have created the spectacular Homunculus Nebula surrounding it. Its present-day wind has the highest mass-loss rate of any hot star weve observed.Picture of Stellar WindTop panel: February 2017 observations of Eta Carinae in continuum (left) and H-alpha. Middle panel: the normalized radial profile for H-alpha and continuum emission. Bottom panel: the full width at half maximum for H-alpha and continuum emission of Eta Carinae. The H-alpha is about 2.5 to 3 milliarcseconds wider than the continuum. [Adapted from Wu et al. 2017]In our goal to understand the late evolutionary phases of very massive stars, weve developed radiative-transfer models to explain the behavior of Eta Carinae. One of the most well-known models, developed by John Hillier and collaborators in 2001, describes Eta Carinaes mass loss via stellar winds. With the right observations, this model is testable, since it predicts observable locations for different types of emission. In particular, one prediction of the Hillier et al. model is that the dense, ionized winds surrounding the star should emit in H-alpha at distances between 6 and 60 AU, with a peak around 20 AU.This nicely testable hypothesis is rendered less convenient by the fact that its hard to get resolved images of Eta Carinaes H-alpha emission. Its distance from us and the fact that its shrouded in the complex nebula it created have thus far prevented us from resolving the H-alpha emission from this star. Now, however, a team of scientists from Steward Observatory, University of Arizona have changed this.Confirming the ModelLed by Ya-Lin Wu, the team obtained diffraction-limited images of Eta Carinae using the Magellan adaptive optics system. The observations, made in both H-alpha and continuum, show that the H-alpha emitting region is significantly wider than the continuum emitting region, as predicted by the model. In fact, the measured emission implies that the H-alpha line-forming region may have a characteristic emitting radius of 2530 AU in very good agreement with the Hillier et al. stellar-wind model.This confirmation is strong support of the physical wind parameters estimated for Eta Carinae in the model, like the mass-loss rate of 10^-3 solar masses per year. These parameters are enormously helpful as we attempt to understand the physics of strong stellar-wind mass loss and the late evolutionary phases of very massive stars.CitationYa-Lin Wu et al 2017 ApJL 841 L7. doi:10.3847/2041-8213/aa70ed

  1. Miniaturized, Multi-Analyte Sensor Array for the Automated Monitoring of Major Atmospheric Constituents in Spacecraft Environment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — InnoSense LLC (ISL) proposes to develop a miniaturized, multi-analyte sensor for near real-time monitoring of analytes in the spacecraft environment. The proposed...

  2. Tritium concentrations in the atmospheric environment at Rokkasho, Japan before the final testing of the spent nuclear fuel reprocessing plant.

    Science.gov (United States)

    Akata, Naofumi; Kakiuchi, Hideki; Shima, Nagayoshi; Iyogi, Takashi; Momoshima, Noriyuki; Hisamatsu, Shun'ichi

    2011-09-01

    This study aimed at obtaining background tritium concentrations in precipitation and air at Rokkasho where the first commercial spent nuclear fuel reprocessing plant in Japan has been under construction. Tritium concentration in monthly precipitation during fiscal years 2001-2005 had a seasonal variation pattern which was high in spring and low in summer. The tritium concentration was higher than that observed at Chiba City as a whole. The seasonal peak concentration at Rokkasho was generally higher than that at Chiba City, while the baseline concentrations of both were similar. The reason for the difference may be the effect of air mass from the Asian continent which is considered to have high tritium concentration. Atmospheric tritium was operationally separated into HTO, HT and hydrocarbon (CH(3)T) fractions, and the samples collected every 3 d-14 d during fiscal year 2005 were analyzed for these fractions. The HTO concentration as radioactivity in water correlated well with that in the precipitation samples. The HT concentration was the highest among the chemical forms analyzed, followed by the HTO and CH(3)T concentrations. The HT and CH(3)T concentrations did not have clear seasonal variation patterns. The HT concentration followed the decline previously reported by Mason and Östlund with an apparent half-life of 4.8 y. The apparent and environmental half-lives of CH(3)T were estimated as 9.2 y and 36.5 y, respectively, by combining the present data with literature data. The Intergovernmental Panel on Climate Change used the atmospheric lifetime of 12 y for CH(4) to estimate global warming in its 2007 report. The longer environmental half-life of CH(3)T suggested its supply from other sources than past nuclear weapon testing in the atmosphere. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Applications of High Etendue Line-Profile Spectro-Polarimetry to the Study of the Atmospheric and Magnetospheric Environments of the Jovian Icy Moons

    Science.gov (United States)

    Harris, Walter M.; Roesler, Fred L.; Jaffel, Lotfi Ben; Ballester, Gilda E.; Oliversen, Ronald J.; Morgenthaler, Jeffrey P.; Mierkiewicz, Edwin

    2003-01-01

    Electrodynamic effects play a significant, global role in the state and energization of the Earth's ionosphere/magnetosphere, but even more so on Jupiter, where the auroral energy input is four orders of magnitude greater than on Earth. The Jovian magnetosphere is distinguished from Earth's by its rapid rotation rate and contributions from satellite atmospheres and internal plasma sources. The electrodynamic effects of these factors have a key role in the state and energization of the ionosphere-corona- plasmasphere system of the planet and its interaction with Io and the icy satellites. Several large scale interacting processes determine conditions near the icy moons beginning with their tenuous atmospheres produced from sputtering, evaporative, and tectonic/volcanic sources, extending out to exospheres that merge with ions and neutrals in the Jovian magnetosphere. This dynamic environment is dependent on a complex network of magnetospheric currents that act on global scales. Field aligned currents connect the satellites and the middle and tail magnetospheric regions to the Jupiter's poles via flux tubes that produce as bright auroral and satellite footprint emissions in the upper atmosphere. This large scale transfer of mass, momentum, and energy (e.g. waves, currents) means that a combination of complementary diagnostics of the plasma, neutral, and and field network must be obtained near simultaneously to correctly interpret the results. This presentation discusses the applicability of UV spatial heterodyne spectroscopy (SHS) to the broad study of this system on scales from satellite surfaces to Jupiter's aurora and corona.

  4. Assessment of Urbanization on the Integrated Land-Ocean-Atmosphere Environment in Coastal Metropolis in Preparation for HyspIRI

    Science.gov (United States)

    Sequera, Pedro; McDonald, Kyle C.; Gonzalez, Jorge; Arend, Mark; Krakauer, Nir; Bornstein, Robert; Luvll, Jeffrey

    2012-01-01

    The need for comprehensive studies of the relationships between past and projected changes of regional climate and human activity in comple x urban environments has been well established. The HyspIRI preparato ry airborne activities in California, associated science and applicat ions research, and eventually HyspIRI itself provide an unprecedented opportunity for development and implementation of an integrated data and modeling analysis system focused on coastal urban environments. We will utilize HyspIRI preparatory data collections in developing ne w remote sensing-based tools for investigating the integrated urban e nvironment, emphasizing weather, climate, and energy demands in compl ex coastal cities.

  5. Atmospheric volatile organic compound measurements: Distributions and effects on air quality in coastal marine, rural and remote continental environments

    Science.gov (United States)

    Zhou, Yong

    A detailed description of the analytical methods employed for whole air sampling and analysis of atmospheric volatile organic compounds is presented. The system described in this thesis produced high precision measurements for a large suite of nonmethane hydrocarbons, halocarbons, and alkyl nitrates, from part per billion by volume (ppbv) to part per trillion by volume (pptv) levels. The measurement precision for most gases ranged from 1-10%. Results from two subsequent field campaigns (2002 and 2003) conducted in Yellowstone National Park (YNP) are presented. The findings indicate that 2-stroke snowmobile engine emissions furnish large quantities of air toxics to the YNP air shed. Air toxics, which are major components of 2stroke engine exhaust, show large enhancements between the high traffic and low traffic sampling periods. Evaluation of the photochemical history of air masses sampled in the Park reveals that the air toxic emissions were recent and persistent throughout the region and consistent with the 2-stroke exhaust sample fingerprints. Using a box model, the emission fluxes from snowmobile usage in the Park are estimated to be 0.35, 1.12, 0.24, 1.45, and 0.36 Gg/yr for benzene, toluene, ethyl benzene, xylenes, and hexane, respectively. The U.S. annual emissions from snowmobile usage are significant (˜14-21%) with respect to EPA estimates. Results of the atmospheric measurements of short-lived halocarbons are presented from the New England Air Quality Study 2002 campaign, summer 2003 at Thompson Farm (TF) and Great Bay, and the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) 2004 campaign. Elevated levels of bromoform (CHBr3) were frequently observed, with maxima of 37.9 pptv and 47.4 pptv for TF and Appledore Island (AI), respectively. During the ICARTT 2004 campaign, the average levels of CHBr3 and dibromomethane (CH2Br2) were higher at AI (CHBr3 = 14.3 pptv, CH2Br2 = 3.2 pptv) compared to Thompson Farm (CHBr3

  6. Persistent organic pollutants in the atmosphere from urban and industrial environments in the Rhine Valley: PCBs, PCDD/Fs.

    Science.gov (United States)

    Guéguen, Florence; Stille, Peter; Millet, Maurice

    2013-06-01

    Polychlorinated biphenyls (PCBs) and polychlorinated dibenzodioxin and furan (PCDD/F) concentrations in the atmosphere were analysed using passive air samplers (PAS) close to the Rhine River between France and Germany. Collectors were placed in industrial, urban, rural and remote areas (Vosges Mountains) between March 2009 and August 2010, and the mean PCB concentrations (sum of 22 congeners) were 3.3, 3.9, 4.1 and 1.4 ng PAS(-1) day(-1), respectively. Two events during the sampling period were observed in April 2009 and February-March 2010 with the highest PCB concentrations found in the industrial area (19.6 ng PAS(-1) day(-1)). PCDD/F level were measured during these periods, and the maximum concentration observed was from 37.5 fg WHO PAS(-1) day(-1.)

  7. Flaw growth of 7075, 7475, 7050 and 7049 aluminum alloy plate in stress corrosion environments: 4-year marine atmosphere results

    Science.gov (United States)

    Hasse, K. R.; Dorward, R. C.

    1981-01-01

    After nearly 53 months of exposure to marine atmosphere, crack growth in SL DCB specimens from 7075, 7475, 7050, and 7049-T7X plate has slowed to the arbitrary 10 to the -10 power m/sec used to define threshold stress intensity. Because some specimens appear to be approaching crack arrest, the importance of self-loading from corrosion product wedging as a significant driving force for crack propagation in overaged materials is questioned. Crack length-time data were analyzed using a computer curve fitting program which minimized the effects of normal data scatter, and provided a clearer picture of material performance. Precracked specimen data are supported by the results of smooth specimen tests. Transgranular stress corrosion cracking was observed in TL DCB specimens from all four alloys. This process is extremely slow and is characterized by a striated surface morphology.

  8. Venus: The Atmosphere, Climate, Surface, Interior and Near-Space Environment of an Earth-Like Planet

    Science.gov (United States)

    Taylor, Fredric W.; Svedhem, Håkan; Head, James W.

    2018-02-01

    This is a review of current knowledge about Earth's nearest planetary neighbour and near twin, Venus. Such knowledge has recently been extended by the European Venus Express and the Japanese Akatsuki spacecraft in orbit around the planet; these missions and their achievements are concisely described in the first part of the review, along with a summary of previous Venus observations. The scientific discussions which follow are divided into three main sections: on the surface and interior; the atmosphere and climate; and the thermosphere, exosphere and magnetosphere. These reports are intended to provide an overview for the general reader, and also an introduction to the more detailed topical surveys in the following articles in this issue, where full references to original material may be found.

  9. Environment

    International Nuclear Information System (INIS)

    McIntyre, A.D.; Turnbull, R.G.H.

    1992-01-01

    The development of the hydrocarbon resources of the North Sea has resulted in both offshore and onshore environmental repercussions, involving the existing physical attributes of the sea and seabed, the coastline and adjoining land. The social and economic repercussions of the industry were equally widespread. The dramatic and speedy impact of the exploration and exploitation of the northern North Sea resources in the early 1970s, on the physical resources of Scotland was quickly realised together with the concern that any environmental and social damage to the physical and social fabric should be kept to a minimum. To this end, a wide range of research and other activities by central and local government, and other interested agencies was undertaken to extend existing knowledge on the marine and terrestrial environments that might be affected by the oil and gas industry. The outcome of these activities is summarized in this paper. The topics covered include a survey of the marine ecosystems of the North Sea, the fishing industry, the impact of oil pollution on seabirds and fish stocks, the ecology of the Scottish coastline and the impact of the petroleum industry on a selection of particular sites. (author)

  10. Microbial Communities in the Vertical Atmosphere: Effects of Urbanization and the Natural Environment in Four North American Ecosystems

    Science.gov (United States)

    Docherty, K. M.; Lemmer, K. M.; Domingue, K. D.; Spring, A.; Kerber, T. V.; Mooney, M. M.

    2017-12-01

    Airborne transport of microbial communities is a key component of the global ecosystem because it serves as a mechanism for dispersing microbial life between all surface habitats on the planet. However, most of our understanding of airborne microbial distribution is derived from samples collected near the ground. Little is understood about how the vertical layers of the air may act as a habitat filter or how local terrestrial ecosystems contribute to a vast airborne microbial seedbank. Specifically, urbanization may fundamentally alter the terrestrial sources of airborne microbial biodiversity. To address this question, we conducted airborne sampling at minimally disturbed natural sites and paired urban sites in 4 different North American ecosystems: shortgrass steppe, desert scrub, eastern deciduous forest, and northern mesic forest. All natural area sites were co-located with NEON/Ameriflux tower sites collecting atmospheric data. We developed an airborne sampling platform that uses tethered helikites at 3 replicate locations within each ecosystem to launch remote-controlled sampler payloads. We designed sampler payloads to collect airborne bacteria and fungi from 150, 30 and 2 m above the ground. Payload requirements included: ability to be disinfected and remain contaminant-free during transport, remote open/close functionality, payload weight under 6 lbs and automated collection of weather data. After sampling for 6 hours at each location, we extracted DNA collected by the samplers. We also extracted DNA from soil and plant samples collected from each location, and characterized ground vegetation. We conducted bacterial 16S amplicon-based sequencing using Mi-Seq and sequence analysis using QIIME. We used ArcGIS to determine percent land use coverage. Our results demonstrate that terrestrial ecosystem type is the most important factor contributing to differences in airborne bacterial community composition, and that communities differed by ecosystem. The

  11. Aerosol mass spectrometric features of biogenic SOA: observations from a plant chamber and in rural atmospheric environments.

    Science.gov (United States)

    Kiendler-Scharr, Astrid; Zhang, Qi; Hohaus, Thorsten; Kleist, Einhard; Mensah, Amewu; Mentel, Thomas F; Spindler, Christian; Uerlings, Ricarda; Tillmann, Ralf; Wildt, Jürgen

    2009-11-01

    Secondary organic aerosol (SOA) is known to form from a variety of anthropogenic and biogenic precursors. Current estimates of global SOA production vary over 2 orders of magnitude. Since no direct measurement technique for SOA exists, quantifying SOA remains a challenge for atmospheric studies. The identification of biogenic SOA (BSOA) based on mass spectral signatures offers the possibility to derive source information of organic aerosol (OA) with high time resolution. Here we present data from simulation experiments. The BSOA from tree emissions was characterized with an Aerodyne quadrupole aerosol mass spectrometer (Q-AMS). Collection efficiencies were close to 1, and effective densities of the BSOA were found to be 1.3 +/- 0.1 g/cm(3). The mass spectra of SOA from different trees were found to be highly similar. The average BSOA mass spectrum from tree emissions is compared to a BSOA component spectrum extracted from field data. It is shown that overall the spectra agree well and that the mass spectral features of BSOA are distinctively different from those of OA components related to fresh fossil fuel and biomass combustions. The simulation chamber mass spectrum may potentially be useful for the identification and interpretation of biogenic SOA components in ambient data sets.

  12. Flat growth of 7075, 7475, 7050 and 7049 aluminum alloy plate in stress corrosion environments: 2-year marine atmosphere results

    Science.gov (United States)

    Dorward, R. C.; Hasse, K. R.

    1978-01-01

    Marine atmospheric exposure of smooth and precracked specimens from 7075, 7475, 7050 and 7049 plates support the conclusion that for a given strength level, the short transverse stress corrosion resistance of 7050-T7X and 7049-T7X is superior to that of 7075-T7X. The threshold stress intensity (K sub Iscc) for these alloys is about 25 MPa square root m at a yield strength of about 460 MPa; the corresponding yield strength level for 7075-T7X at this SCR level is about 425 MPa. Additional tests on two lots of high-toughness 7475 plate indicate that this alloy is capable of achieving K sub Iscc values of about 35 MPa square root m at yield strengths of 400-450 MPa. Precracked specimens from all these 7XXX-series alloys are subject to self loading from corrosion product wedging. This effect causes stress corrosion cracks to continue growing at very low apparent stress intensities, and should therefore be considered a potential driving force for stress corrosion in design and materials selection.

  13. Study of meteorological aspects and urban concentration of SO2 in atmospheric environment of La Plata, Argentina.

    Science.gov (United States)

    Ratto, Gustavo; Videla, Fabián; Almandos, J Reyna; Maronna, Ricardo; Schinca, Daniel

    2006-10-01

    This article presents and discusses SO(2) (ppbv) concentration measurements combined with meteorological data (mainly wind speed and direction) for a five-year campaign (1996 to 2000), in a site near an oil refinery plant close to the city of La Plata and surroundings (aprox. 740.000 inh.), considered one of the six most affected cities by air pollution in the country. Since there is no monitoring network in the area, the obtained results should be considered as medium term accumulated data that enables to determine trends by analyzing together gas concentrations and meteorological parameters. Preliminary characterization of the behaviour of the predominant winds of the region in relation with potential atmospheric gas pollutants from seasonal wind roses is possible to carry out from the data. These results are complemented with monthly averaged SO(2) measurements. In particular, for year 2000, pollutant roses were determined which enable predictions about contamination emission sources. As a general result we can state that there is a clear increase in annual SO(2) concentration and that the selected site should be considered as a key site for future survey monitoring network deployment. Annual SO(2) average concentration and prevailing seasonal winds determined in this work, together with the potential health impact of SO(2) reveals the need for a comprehensive and systematic study involving particulate matter an other basic pollutant gases.

  14. Atmospheric dry deposition in the vicinity of the Salton Sea, California - I: Air pollution and deposition in a desert environment

    Science.gov (United States)

    Alonso, R.; Bytnerowicz, A.; Boarman, W.I.

    2005-01-01

    Air pollutant concentrations and atmospheric dry deposition were monitored seasonally at the Salton Sea, southern California. Measurements of ozone (O 3), nitric acid vapor (HNO3), ammonia (NH3), nitric oxide (NO), nitrogen dioxide (NO2) and sulfur dioxide (SO 2) were performed using passive samplers. Deposition rates of NO 3-, NH4+, Cl-, SO 42-, Na+, K+ and Ca2+ to creosote bush branches and nylon filters as surrogate surfaces were determined for one-week long exposure periods. Maximum O3 values were recorded in spring with 24-h average values of 108.8 ??g m-3. Concentrations of NO and NO2 were low and within ranges of the non-urban areas in California (0.4-5.6 and 3.3-16.2 ??g m-3 ranges, respectively). Concentrations of HNO3 (2.0-6.7 ??g m-3) and NH 3 (6.4-15.7 ??g m-3) were elevated and above the levels typical for remote locations in California. Deposition rates of Cl-, SO42-, Na+, K+ and Ca2+ were related to the influence of sea spray or to suspended soil particles, and no strong enrichments caused by ions originated by human activities were detected. Dry deposition rates of NO3- and NH4+ were similar to values registered in areas where symptoms of nitrogen saturation and changes in species composition have been described. Deposition of nitrogenous compounds might be contributing to eutrophication processes at the Salton Sea. ?? 2005 Elsevier Ltd. All rights reserved.

  15. Response of water vapour D-excess to land–atmosphere interactions in a semi-arid environment

    Directory of Open Access Journals (Sweden)

    S. D. Parkes

    2017-01-01

    large variability during the night. These results indicate dET can generally be expected to show large spatial and temporal variability and to depend on the soil moisture state. For long periods between rain events, common in semi-arid environments, ET would be expected to impose negative forcing on the surface dv. Spatial and temporal variability of D-excess in ET fluxes therefore needs to be considered when using dv to study moisture recycling and during extended dry periods with weak moisture recycling may act as a tracer of the relative humidity at the oceanic moisture source.

  16. flexCloud: Deployment of the FLEXPART Atmospheric Transport Model as a Cloud SaaS Environment

    Science.gov (United States)

    Morton, Don; Arnold, Dèlia

    2014-05-01

    FLEXPART (FLEXible PARTicle dispersion model) is a Lagrangian transport and dispersion model used by a growing international community. We have used it to simulate and forecast the atmospheric transport of wildfire smoke, volcanic ash and radionuclides. Additionally, FLEXPART may be run in backwards mode to provide information for the determination of emission sources such as nuclear emissions and greenhouse gases. This open source software is distributed in source code form, and has several compiler and library dependencies that users need to address. Although well-documented, getting it compiled, set up, running, and post-processed is often tedious, making it difficult for the inexperienced user. Our interest is in moving scientific modeling and simulation activities from site-specific clusters and supercomputers to a cloud model as a service paradigm. Choosing FLEXPART for our prototyping, our vision is to construct customised IaaS images containing fully-compiled and configured FLEXPART codes, including pre-processing, execution and postprocessing components. In addition, with the inclusion of a small web server in the image, we introduce a web-accessible graphical user interface that drives the system. A further initiative being pursued is the deployment of multiple, simultaneous FLEXPART ensembles in the cloud. A single front-end web interface is used to define the ensemble members, and separate cloud instances are launched, on-demand, to run the individual models and to conglomerate the outputs into a unified display. The outcome of this work is a Software as a Service (Saas) deployment whereby the details of the underlying modeling systems are hidden, allowing modelers to perform their science activities without the burden of considering implementation details.

  17. Estimating Tritium Fluxes from the Shallow Unsaturated Zone to the Atmosphere in an Arid Environment Dominated by Creosote Bush (USGS-ADRS)

    Science.gov (United States)

    Garcia, C. A.; Andraski, B. J.; Wheatcraft, S. W.; Johnson, M. J.; Michel, R. L.; Stonestrom, D. A.

    2006-12-01

    Understanding the transport and fate of tritium is essential when evaluating options for low-level radioactive waste (LLRW) isolation. The magnitude and spatio-temporal variability of tritium transport from the shallow unsaturated zone to the atmosphere are being investigated adjacent to a LLRW facility at the U.S. Geological Survey's Amargosa Desert Research Site (ADRS) in Southern Nevada. Site and community-scale tritium fluxes from the subsurface to the atmosphere were quantified using a simple gas-phase diffusive loading approach combining evaporation and transpiration fluxes with mass fractions of gas-phase tritium concentrations. A Priestly-Taylor model, calibrated with quarterly bare-soil evaporation measurements, was used to estimate continuous bare-soil evaporation from measured continuous eddy-covariance evapotransporation. Continuous transpiration was computed as the difference between measured evapotranspiration and estimated bare-soil evaporation. Tritium concentrations in plant water and soil-water vapor were measured along two transects perpendicular to the LLRW using azeotropic distillation of creosote bush (Larrea tridentata) foliage and soil vapor extraction from 0.5 and 1.5 m depths below land surface. A preliminary daily tritium flux estimate at a single plant site was 1.66 × 10-11 gm-2. Spatio- temporal variability over a 75-ha area and 2-yr period will be quantified using a combination of tritium concentration maps and continuous evaporation and transpiration flux estimates. Quantifying tritium fluxes from the shallow unsaturated zone to the atmosphere on a site and community-scale will improve knowledge and understanding of vertical contaminant transport in arid environments.

  18. Nature and sources of particle associated polycyclic aromatic hydrocarbons (PAH) in the atmospheric environment of an urban area

    International Nuclear Information System (INIS)

    Callén, M.S.; López, J.M.; Iturmendi, A.; Mastral, A.M.

    2013-01-01

    The total PAH associated to the airborne particulate matter (PM10) was apportioned by one receptor model based on positive matrix factorization (PMF) in an urban environment (Zaragoza city, Spain) during February 2010–January 2011. Four sources associated with coal combustion, gasoline, vehicular and stationary emissions were identified, allowing a good modelling of the total PAH (R 2 = 0.99). A seasonal behaviour of the four factors was obtained with higher concentrations in the cold season. The NE direction was one of the predominant directions showing the negative impact of industrial parks, a paper factory and a highway located in that direction. Samples were classified according to hierarchical cluster analysis obtaining that, episodes with the most negative impact on human health (the highest lifetime cancer risk concentrations), were produced by a higher contribution of stationary and vehicular emissions in winter season favoured by high relative humidity, low temperature and low wind speed. -- Highlights: ► PMF receptor model apportioned four sources associated to the total PAH in Zaragoza. ► The sources were: vehicular, coal combustion, gasoline and stationary emissions. ► Samples were additionally classified according to hierarchical cluster analysis. ► The stationary and vehicular emissions factors showed higher risk for human health. ► Low temperature, wind speed and high relative humidity favoured this negative impact. -- Episodes with the most negative impact on human health regarding PAH were produced by a higher contribution of stationary and vehicular emissions in winter season

  19. Response of water vapour D-excess to land–atmosphere interactions in a semi-arid environment

    KAUST Repository

    Parkes, Stephen

    2017-01-27

    The stable isotopic composition of water vapour provides information about moisture sources and processes difficult to obtain with traditional measurement techniques. Recently, it has been proposed that the D-excess of water vapour (d =δH-8× δO) can provide a diagnostic tracer of continental moisture recycling. However, D-excess exhibits a diurnal cycle that has been observed across a variety of ecosystems and may be influenced by a range of processes beyond regional-scale moisture recycling, including local evaporation (ET) fluxes. There is a lack of measurements of D-excess in evaporation (ET) fluxes, which has made it difficult to assess how ET fluxes modify the Dexcess in water vapour (d). With this in mind, we employed a chamber-based approach to directly measure D-excess in ET (d) fluxes. We show that ET fluxes imposed a negative forcing on the ambient vapour and could not explain the higher daytime d values. The low d observed here was sourced from a soil water pool that had undergone an extended drying period, leading to low D-excess in the soil moisture pool. A strong correlation between daytime d and locally measured relative humidity was consistent with an oceanic moisture source, suggesting that remote hydrological processes were the major contributor to daytime d variability. During the early evening, ET fluxes into a shallow nocturnal inversion layer caused a lowering of d values near the surface. In addition, transient mixing of vapour with a higher D-excess from above the nocturnal inversion modified these values, causing large variability during the night. These results indicate d can generally be expected to show large spatial and temporal variability and to depend on the soil moisture state. For long periods between rain events, common in semi-arid environments, ET would be expected to impose negative forcing on the surface d. Spatial and temporal variability of D-excess in ET fluxes therefore needs to be considered when using d to study

  20. Atmospheric monitoring

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Radioactivity in air was measured by a network of continuously operating air samplers at nineteen locations near the Site perimeter and five locations somewhat distant from the Site. The Site perimeter samplers provided for general coverage in all directions but with emphasis in the prevalent downwind directions to the south and east of the Site including the communities of Benton City, Richland, Pasco, Connell, and Othello. The distant air sample locations provided background airborne radioactivity data for comparison. These samplers were located at Sunnyside, Moses Lake, Washtucna, Walla Walla, and at McNary Dam. Airborne radionuclide concentrations during 1982 were lower than those observed in 1981 because of the gradual decline of atmospheric fallout associated with a foreign atmospheric nuclear test that occurred in the fall of 1980. Airborne radioactivity data collected during 1982 did not indicate the presence of detectable levels of Hanford origin radionuclides in the offsite environs

  1. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  2. Atmosphere physics and chemistry

    International Nuclear Information System (INIS)

    Delmas, R.; Megie, G.; Peuch, V.H.

    2005-10-01

    Since the 1970's, the awareness about the atmospheric pollution threat has led to a spectacular development of the researches on the complex interactions between the chemical composition of the atmosphere and the climate. This book makes a synthesis of the state-of-the-art in this very active domain of research. Content: introduction, atmosphere dynamics and transport, matter-radiation interaction and radiant transfer, physico-chemical processes, atmospheric aerosol and heterogenous chemistry, anthropic and natural emissions and deposition, stratospheric chemical system, tropospheric chemical system, polluted boundary layer, paleo-environments and ice archives, role of atmospheric chemistry in global changes, measurement principles and instruments, numerical modeling, experimental strategy, regulation and management of the atmospheric environment, index. (J.S.)

  3. Seasonal and Diurnal Variation of Atmospheric Fungal Spore Concentrations in Hyderabad; Tandojam-Sindh and the Effects of Climatic Conditions

    International Nuclear Information System (INIS)

    Khan, M.; Parveen, A.; Qaisar, M.

    2016-01-01

    Airborne biological particles are present in every type of environment. Different types of geographical localities have different type of airspora, which affect human health. The current study is conducted for the first time to identify the airborne fungal spores from Hyderabad: Tando-Jam, Sindh. For this purpose, Burkard's 7-Days recording volumetric spore trap was used for a period of one year. A total of 68,183 spores/m/sup 3/ were recorded throughout the study period, belonging to 41 fungal spores types. The presented data revealed that Deuteromycetes spore type was predominant. Cladosporium sp. spores were detected in the highest concentration i.e., 50.83 percent, which was followed by Aspergillus sp. (18.63 percent) and Alternaria sp. (11.04 percent). The highest spore count was captured in the month of September-2008 (17,294 spores/m/sup 3/), while lowest spore count was found in the month of June-2009. Diurnal patterns of individual fungal spore types was observed to be mid-day to evening maxima for various species. Spearman rank correlation coefficient r was determined for correlation of fungal spore counts with climatic factors by using IBM software SPSS ver. 20. Results of the current study revealed that fungal spore concentration was increased in high humid weather while low count was found in hot and windy climate that was also confirmed by statistical analysis. The presented work demonstrated that various types of allergenic and phytopathogenic fungal spores were present in the atmosphere of Hyderabad: Tando-Jam. It was also observed that meteorological conditions had a significant impact on dispersal and concentration of fungal spores. (author)

  4. Jovian atmospheres

    International Nuclear Information System (INIS)

    Allison, M.; Travis, L.D.

    1986-10-01

    A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers

  5. Development of the Finse Alpine Research Station towards a platform for multi-disciplinary research on Land-Atmosphere Interaction in Cold Environments (LATICE)

    Science.gov (United States)

    Burkhart, John F.; Decker, Sven; Filhol, Simon; Hulth, John; Nesje, Atle; Schuler, Thomas V.; Sobolowski, Stefan; Tallaksen, Lena M.

    2017-04-01

    The Finse Alpine Research Station provides convenient access to the Hardangervidda mountain plateau in Southern Norway (60 deg N, 1222 m asl). The station is located above the tree-line in vicinity to the west-eastern mountain water divide and is easily accessible by train from Bergen and Oslo. The station itself offers housing and basic laboratory facilities and has been used for ecological monitoring. Over the past years, studies on small-scale snow distribution and ground temperature have been performed and accompanied by a suite of meteorological measurements. Supported by strategic investments by the University of Oslo and ongoing research projects, these activities are currently expanded and the site is developed towards a mountain field laboratory for studies on Land-Atmosphere Interaction in Cold Environments, facilitated by the LATICE project (www.mn.uio.no/latice). Additional synergy comes from close collaborations with a range of institutions that perform operational monitoring close to Finse, including long-term time series of meteorological data and global radiation. Through our activities, this infrastructure has been complemented by a permanent tower for continuous Eddy-Covariance measurements along with associated gas fluxes. A second, mobile covariance system is in preparation and will become operational in 2017. In addition, a wireless sensor network is set up to grasp the spatial distributions of basic meteorological variables, snow depth and glacier mass balance on the nearby Hardangerjøkulen ice cap. While the research focus so far was on small scale processes (snow redistribution), this is now being expanded to cover hydrological processes on the catchment and regional scale. To this end, two discharge stations have been installed to gauge discharge from two contrasting catchments (glacier dominated and non-glacierized). In this presentation, we provide an overview over existing and planned infrastructure, field campaigns and research

  6. Climate change effects on environment (marine, atmospheric and terrestrial) and human perception in an Italian Region (Marche) and the nearby northern Adriatic Sea.

    Science.gov (United States)

    Appiotti, F.; Krzelj, M.; Marincioni, F.; Russo, A.

    2012-04-01

    An integrated analysis of recent climate change, including atmosphere, sea and land, as well as some of the impacts on society, has been conducted on the Marche Region in central Italy and the northern portion of the Adriatic Sea. The Marche Region is one of the 20 administrative divisions of Italy, located at a latitude approximately 43° North, with a total surface area of 9,366 km2 and 1,565,000 residents. The northern Adriatic Sea is the northernmost area of the Mediterranean Sea, and it has peculiar relevance for several aspects (environment, tourism, fisheries, economy). The collected environmental data included meteorological stations (daily maximum and minimum air temperature, daily precipitation), oceanographic stations (sea temperature, salinity, dissolved oxygen, nutrient salts concentration, chlorophyll) and river flows, over the last 50 years. The collected social data include 800 questionnaires and interviews carried out on selected samples of residents, decision-makers and emergency managers. These questionnaires and interviews aimed at highlighting the perception of climate change risks. The trend analysis of air temperature and precipitation data detailed an overall temperature increase in all seasons and rainfall decreases in Winter, Spring and Summer with Autumn increases, influencing river flow changes. Marine data showed a relevant warming of the water column in the period after 1990 in comparison with the previous period, particularly in the cold season. Surface salinity increased in Spring and Summer and strongly decreased in Autumn and Winter (according with the precipitation and river flow changes). These last mentioned changes, combined with anthropogenic effects, also influenced the marine ecosystems, with changes of nutrient salts, chlorophyll and dissolved oxygen. Changes in nutrient discharge from rivers influenced the average marine chlorophyll concentration reduction and the consequent average reduction of warm season hypoxic

  7. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    International Nuclear Information System (INIS)

    Yates, Jack S.; Palmer, Paul I.; Biller, Beth; Cockell, Charles S.

    2017-01-01

    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10"9 cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  8. Atmospheric Habitable Zones in Y Dwarf Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Jack S.; Palmer, Paul I. [School of GeoSciences, University of Edinburgh (United Kingdom); Biller, Beth; Cockell, Charles S., E-mail: j.s.yates@ed.ac.uk [Centre for Exoplanet Science, University of Edinburgh (United Kingdom)

    2017-02-20

    We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2 μ m spectrum shows absorption features consistent with water vapor and clouds. We allow organisms to adapt to their atmospheric environment (described by temperature, convection, and gravity) by adopting different growth strategies that maximize their chance of survival and proliferation. We assume a constant upward vertical velocity through the AHZ. We found that the organism growth strategy is most sensitive to the magnitude of the atmospheric convection. Stronger convection supports the evolution of more massive organisms. For a purely radiative environment, we find that evolved organisms have a mass that is an order of magnitude smaller than terrestrial microbes, thereby defining a dynamical constraint on the dimensions of life that an AHZ can support. Based on a previously defined statistical approach, we infer that there are of the order of 10{sup 9} cool Y brown dwarfs in the Milky Way, and likely a few tens of these objects are within 10 pc from Earth. Our work also has implications for exploring life in the atmospheres of temperate gas giants. Consideration of the habitable volumes in planetary atmospheres significantly increases the volume of habitable space in the galaxy.

  9. Source apportionment of atmospheric particulate matter (PM) using a constrained US-EPA-PMF5.0 model at different urban environments in France

    Science.gov (United States)

    Salameh, Dalia; Favez, Olivier; Golly, Benjamin; Besombes, Jean Luc; Alleman, Laurent; Albinet, Alexandre; Jaffrezo, Jean Luc

    2017-04-01

    Particulate matter (PM) is one of the most studied atmospheric pollutant in urban areas due to their adverse effects on human health (Pope et al., 2009). Intrinsic properties of PM (e.g. chemical composition and morphology) are directly linked to their origins. Therefore, a harmonized and comprehensive apportionment study of PM sources in urban environments is extremely required to connect source contributions with PM concentration levels and then develop effective PM abatement strategies. Multivariate receptor models such as Positive Matrix Factorization (PMF) are very useful and have been used worldwide for PM source apportionment (Viana et al., 2008). PMF uses a weighted least-squares fit and quantitatively determines source fingerprints (factors) and their contributions to the total PM mass. However, in many cases, it could be tricky to separate two factors that co-vary due to similar seasonal variations, making unclear the physical sense of the extracted factors. To address such issues of source collinearities, additional specific constraints are incorporated into the model (i.e., constrained PMF) based on user's external knowledge allowing better apportionment results. In this work and within the framework of the SOURCES project, a harmonized source apportionment approach has been implemented and applied for the determination of PM sources on a large number of sites (up to 20) of different typologies (e.g. urban background, industrial, traffic, rural and/or alpine sites) distributed all over France and previously investigated with annual or multiannual studies (2012-2016). A constrained PMF approach (using US-EPA PMF5.0 software) was applied to the comprehensive PM-offline chemical datasets (i.e. carbonaceous fraction, major ions, metals/trace elements, specific organic markers) in a harmonized way for all the investigated sites. Different types of specific chemical constraints from well-characterized sources were defined based on external knowledge and were

  10. Setting up an atmospheric-hydrologic model for seasonal forecasts of water flow into dams in a mountainous semi-arid environment (Cyprus)

    Science.gov (United States)

    Camera, Corrado; Bruggeman, Adriana; Zittis, Georgios; Hadjinicolaou, Panos

    2017-04-01

    partitioning of deep percolation between losses and baseflow contribution (LOSS_BASE), water retention depth (RETDEPRTFAC), overland roughness (OVROUGHRTFAC), and channel manning coefficients (MANN). The calibrated WRF-Hydro shows a good ability to reproduce annual total streamflow (-19% error) and total peak discharge volumes (+3% error), although very high values of MANN were used to match the timing of the peak and get positive values of Nash-Sutcliffe efficiency coefficient (0.13). The two most sensitive parameters for the modeled seasonal flow were REFKDT and LOSS_BASE. Simulations of the calibrated WRF-Hydro with WRF modelled atmospheric forcing showed high errors in comparison with those forced with observations, which can be corrected only by modifying the most sensitive parameters by at least one order of magnitude. This study has received funding from the EU H2020 BINGO Project (GA 641739). Camera C., Bruggeman A., Hadjinicolaou P., Pashiardis S., Lange M.A., 2016. Evaluation of interpolation techniques for the creation of gridded daily precipitation (1 × 1 km2); Cyprus, 1980-2010. J Geophys Res Atmos 119, 693-712, DOI:10.1002/2013JD020611 Camera C., Bruggeman A., Hadjinicolaou P., Michaelides S., Lange M.A., 2016. Evaluation of a spatial rainfall generator for generating high resolution precipitation projections over orographically complex terrain. Stoch Environ Res Risk Assess, DOI 10.1007/s00477-016-1239-1

  11. Physical profile data collected during the calendar year 2003 for the Tropical Atmosphere Ocean Project by NOAA's Pacific Marine Environment Lab (NODC Accession 0001364)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical profile data were collected using meteorological sensors and CTD casts in the Northeast Pacific Ocean from NOAA Ship KA'IMIMOANA and NOAA Ship RONALD H....

  12. Effects of chronic exposure to low-level pollutants in the environment. Prepared for the Subcommittee on the Environment and the Atmosphere of the Committee on Science and Technology, US House of Representatives, Ninety-Fourth Congress, First Session by the Congressional Research Service, Library of Congress, Serial 0

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    This report was prepared for the Subcommittee on the Environment and the Atmosphere of the US House of Representatives Committee on Science and Technology. It describes the effects of low-level, persistent pollutants on human health, fish and wildlife, agriculture, and climate.

  13. Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record

    DEFF Research Database (Denmark)

    Møller, Henrik S.; Jensen, Karin G.; Kuijpers, Antoon

    2006-01-01

    to large-scale North Atlantic ocean and climate variability. AMS 14C-dating of benthic foraminifera indicates that the sediment core covers the last 4400 years and may include the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates...... conditions were further characterised by limited sea ice probably related to a mild and relatively windy winter climate. After 3.2 ka BP lower fine-grained sedimentation rates, but a larger input from sea-ice rafted or aeolian coarse material prevailed. This can be related to colder atmospheric conditions...

  14. Understanding Callisto's Atmosphere

    Science.gov (United States)

    Spencer, John

    2016-10-01

    We plan to address first-order questions about the nature and origin of the mysterious atmosphere of Callisto, including its composition, longitudinal distribution, formation, and support mechanisms. This investigation is made possible by the remarkable sensitivity of the COS instrument, which has recently detected faint 1304 A and 1356 A O I emission from Callisto's leading / Jupiter-facing quadrant. The emission is probably due to dissociation of O2 molecules in Callisto's atmosphere by photo-electrons, and resonant scattering from an extended atomic O corona. We suspect, from Galileo ionospheric data, that the atmosphere may be much denser, and brighter in emission, on the trailing hemisphere, as expected for a sputter-generated atmosphere, and propose to test the sputter generation hypothesis with 4-orbit COS integrations on the leading and trailing hemispheres. If the trailing side emissions are indeed brighter, the improved SNR there will also allow much improved determination of atmospheric and coronal composition and optical depth. The observations will set the stage for, and aid in planning of, the extensive observations of Callisto's environment planned for the JUICE mission. Because Callisto's atmospheric oxygen emissions are indirectly illuminated by sunlight, which is uniform and quantifiable, it is much easier to understand atmospheric spatial distribution, and thus origin, than on Europa and Ganymede were emissions depend on magnetospheric excitation which is spatially variable and poorly understood. Callisto's atmosphere thus provides a unique chance to better understand the oxygen atmospheres of all the icy Galilean moons.

  15. Fluxes of Ethanol Between the Atmosphere and Oceanic Surface Waters; Implications for the Fate of Biofuel Ethanol Released into the Environment

    Science.gov (United States)

    Avery, G. B., Jr.; Shimizu, M. S.; Willey, J. D.; Mead, R. N.; Skrabal, S. A.; Kieber, R. J.; Lathrop, T. E.; Felix, J. D. D.

    2017-12-01

    The use of ethanol as a transportation fuel has increased significantly during the past decade in the US. Some ethanol escapes the combustion process in internal combustion engines resulting in its release to the atmosphere. Ethanol can be oxidized photochemically to acetaldehyde and then converted to peroxyacetyl nitrate contributing to air pollution. Therefore it is important to determine the fate ethanol released to the atmosphere. Because of its high water solubility the oceans may act as a sink for ethanol depending on its state of saturation with respect to the gas phase. The purpose of the current study was to determine the relative saturation of oceanic surface waters by making simultaneous measurements of gas phase and surface water concentrations. Data were obtained from four separate cruises ranging from estuarine to open ocean locations in the coast of North Carolina, USA. The majority of estuarine sites were under saturated in ethanol with respect to the gas phase (11-50% saturated) representing a potential sink. Coastal surface waters tended to be supersaturated (135 - 317%) representing a net flux of ethanol to the atmosphere. Open ocean samples were generally at saturation or slightly below saturation (76-99%) indicating equilibrium between the gas and aqueous phases. The results of this study underscore to variable role the oceans play in mitigating the increases in atmospheric ethanol from increased biofuel usage and their impact on air quality.

  16. Proterozoic atmospheric oxygen

    DEFF Research Database (Denmark)

    Canfield, Donald Eugene

    2014-01-01

    This article is concerned with the evolution of atmospheric oxygen concentrations through the Proterozoic Eon. In particular, this article will seek to place the history of atmospheric oxygenation through the Proterozoic Eon in the context of the evolving physical environment including the history...... of continental growth and volcanic outgassing, as well as biogeochemical processing of elements within the oceans. The author will seek to explore constraints on the history of oxygenation and understand which processes have regulated oxygen through this eon....

  17. Observing pre-earthquake features in the Earth atmosphere-ionosphere environment associated with 2017 Tehuantepec and Puebla earthquakes in Mexico

    Science.gov (United States)

    Ouzounov, D.; Pulinets, S. A.; Guiliani, G.; Hernandez-Pajares, M.; Garcia-Rigo, A.; Petrov, L.; Taylor, P. T.; Hatzopoulos, N.; Kafatos, M.

    2017-12-01

    We are presenting a multi parameter study of lithosphere/atmosphere /ionosphere transient phenomena observed in advance of the M8.2 Tehuantepec and M7.1Puebla earthquakes, the largest and most damaging earthquakes ever recorded in Mexico. We are collecting data from four instruments which recorded hourly and daily: 1.Ground Radon variations (Gamma network in Southern CA) ; 2. Outgoing long-wavelength radiation (OLR obtained from NPOES) on the top of the atmosphere (TOA), 3. Atmospheric chemical potential (ACP) obtained from NASA assimilation models and 4. Electron density variations in the ionosphere via GPS Total Electron Content (GPS/TEC). The September M8.2 earthquake was situated about 3200 kilometers south of two-radon monitoring stations in Orange, Southern California. Real time hourly data show a sharp increase on both sensors (160 kilometers apart) on Sept 2 ( 6 days prior to the M8.2 of 09.08.2017 ) and second anomaly appeared again on Sept 11 ( 7 days prior to the M7.1 of 09.19.2017). Those increases in radon coincide (with some delay) with an increase in the atmospheric chemical potential (on Sept. 03 and10 respectively) measured near the epicentral area from satellite data. And subsequently at the end of August there was an increase of infrared radiation observed which was associated with the acceleration of OLR at the TOA observed from NOAA polar orbit satellites reaching a maximum near the epicenter on Sept 5 and Sept 17. The GPS/Total Electron Content data indicated an increase of electron concentration in ionosphere on Sep 7 and Sep 18, 1-2 days before both earthquakes. Before the earthquake ground and satellite data both show a synergetic anomalous trend, a week before the M8.2 Tehuantepec of 09.08.2017 and continuously up to the Puebla earthquake(M7.1 of 09.19.2017) , although the radon variations were observed far from both epicentral areas. We examined the possible correlation between different pre-earthquake signals in the frame of a

  18. Cl K-edge XANES spectra of atmospheric rust on Fe, Fe-Cr and Fe-Ni alloys exposed to saline environment

    International Nuclear Information System (INIS)

    Konishi, Hiroyuki; Mizuki, Jun'ichiro; Yamashita, Masato; Uchida, Hitoshi

    2004-01-01

    Cl K-edge XANES measurements of atmospheric corrosion products (rust) formed on Fe, Fe-Ni and Fe-Cr alloys in chloride pollution have been performed using synchrotron radiation in order to clarify roles of anticorrosive alloying elements and of Cl in the corrosion resistance of weathering steel. The spectra of binary alloys show a shoulder structure near the absorption edge. The intensity of the shoulder peak depends on the kind and amount of the alloying element, whereas the energy position is invariant. This indicates that Cl is not combined directly with alloying elements in the rust. (author)

  19. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  20. Atmospheric Neutrinos

    Directory of Open Access Journals (Sweden)

    Takaaki Kajita

    2012-01-01

    Full Text Available Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

  1. Effect of Aluminum and Silicon on Atmospheric Corrosion of Low-alloying Steel under Containing NaHSO3 Wet/dry Environment

    International Nuclear Information System (INIS)

    Xinhua, Chen; Junhua, Dong; Enhou, Han; Wei, Ke

    2008-01-01

    The atmospheric corrosion performance of Al-alloying Si-alloying and Al-Si-alloying steel were studied by wet/dry cyclic corrosion tests (CCT) at 30 .deg. C and 60% relative humidity (RH). The corrosion electrolyte used for CCT was 0.052 wt% NaHSO 3 (pH∼4) solution. The result of gravimetry demonstrated that Al-Si-bearing steels showed lower corrosion resistance than other rusted steels. But the rusted 0.7%Si-alloying steel showed a better corrosion resistance than rusted mild steel. Polarization curves demonstrated that Al-/Si-alloying and Al-Si-alloying improved the rest potential of steel at the initial stage: and accelerated the cathodic reduction and anodic dissolution after a rust layer formed on the surfaces of steels. XRD results showed that Al-Si-alloying decreased the volume fraction of Fe 3 O 4 and α-FeOOH. The recycle of acid accelerated the corrosion of steel at the initial stage. After the rust layer formed on the steel, the leak of rust destabilized the rust layer due to the dissolution of compound containing Al (such as FeAl 2 O 4 , (Fe, Si) 2 (Fe, Al)O 4 ). Al-Si-alloying is hence not suitable for improving the anti-corrosion resistance of steel in industrial atmosphere

  2. Atmospheric electrodynamics

    International Nuclear Information System (INIS)

    Volland, H.

    1984-01-01

    The book Atmospheric Electrodynamics, by Hans Voland is reviewed. The book describes a wide variety of electrical phenomena occurring in the upper and lower atmosphere and develops the mathematical models which simulate these processes. The reviewer finds that the book is of interest to researchers with a background in electromagnetic theory but is of only limited use as a reference work

  3. Atmospheric Dispositifs

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2015-01-01

    , the conceptual foundations and protocols for the production of atmosphere in architecture might be found beneath the surface of contemporary debates. In this context, the notion of atmospheric dispositif – illustrated through an oeuvre of the German architect Werner Ruhnau and its theoretical and historical...

  4. Jerks as Guiding Influences on the Global Environment: Effects on the Solid Earth, Its Angular Momentum and Lithospheric Plate Motions, the Atmosphere, Weather, and Climate

    Science.gov (United States)

    Quinn, J. M.; Leybourne, B. A.

    2010-12-01

    Jerks are thought to be the result of torques applied at the core-mantle boundary (CMB) caused by either of two possible processes, working together or separately: 1) Electromagnetic Induction and 2) Mechanical Slippage. In the first case, it is thought that electromagnetic energy slowly builds-up at the CMB, reaches some critical level, and is then suddenly released, causing a geomagneticly induced torque at the CMB due to the differential electrical conductivity between the lower mantle and the surface of the outer core. The second case is driven by stress and strain increases that buildup mechanical potential energy, which is released when a critical level is reached, thereby generating a torque at the CMB. Generally, a trigger is required to start the Jerk process in motion. In the electromagnetic case, it is suggested that energy from the Sun may supply the requisite energy buildup that is subsequently released by a magnetic storm trigger, for instance. In the case of mechanical slippage, bari-center motion among the Earth, Moon, and Sun, as well as tidal forces and mass redistributions through Earth's wobbles combine to provide the accumulated stress/strain buildup and subsequent trigger. The resulting fluid flow changes at the CMB result in geomagnetic field changes and Joule heating throughout the solid Earth, its oceans, and atmosphere. It is shown that the Global Temperature Anomaly (GTA), which is measured at Earth's surface, correlates with changes in the geomagnetic non-dipole moment, and thus with core fluid motions. This links Global Warming and weather with core processes, important examples being the 1930's Dust Bowl Era and the 1947 Impulse. The CMB torque also affects Earth's angular momentum. But it appears that magnetic storms can as well. As a consequence, the Jet Stream, atmospheric circulation patterns, and the Global Oscillation System (i.e., El-Nino/Southern-Oscillation, North Atlantic Oscillation, the Pacific Decade Oscillation, etc.) are

  5. Urban atmospheres.

    Science.gov (United States)

    Gandy, Matthew

    2017-07-01

    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  6. Stabilization of atmospheric carbon dioxide via zero emissions—An alternative way to a stable global environment. Part 1: Examination of the traditional stabilization concept

    Science.gov (United States)

    MATSUNO, Taroh; MARUYAMA, Koki; TSUTSUI, Junichi

    2012-01-01

    The concept of “stabilization” of atmospheric CO2 concentration is re-examined in connection with climate-change mitigation strategies. A new “zero-emissions stabilization (Z-stabilization)” is proposed, where CO2 emissions are reduced to zero at some time and thereafter the concentration is decreased by natural removal processes, eventually reaching an equilibrated stable state. Simplified climate experiments show that, under Z-stabilization, considerably larger emissions are permissible in the near future compared with traditional stabilization, with the same constraint on temperature rise. Over longer time scales, the concentration and temperature decrease close to their equilibrium values, much lower than those under traditional stabilization. The smaller temperature rise at final state is essential to avoid longer-term risk of sea level rise, a significant concern under traditional stabilization. Because of these advantages a Z-stabilization pathway can be a candidate of practical mitigation strategies as treated in Part 2. PMID:22850727

  7. Stabilization of atmospheric carbon dioxide via zero emissions--an alternative way to a stable global environment. Part 1: examination of the traditional stabilization concept.

    Science.gov (United States)

    Matsuno, Taroh; Maruyama, Koki; Tsutsui, Junichi

    2012-01-01

    The concept of "stabilization" of atmospheric CO(2) concentration is re-examined in connection with climate-change mitigation strategies. A new "zero-emissions stabilization (Z-stabilization)" is proposed, where CO(2) emissions are reduced to zero at some time and thereafter the concentration is decreased by natural removal processes, eventually reaching an equilibrated stable state. Simplified climate experiments show that, under Z-stabilization, considerably larger emissions are permissible in the near future compared with traditional stabilization, with the same constraint on temperature rise. Over longer time scales, the concentration and temperature decrease close to their equilibrium values, much lower than those under traditional stabilization. The smaller temperature rise at final state is essential to avoid longer-term risk of sea level rise, a significant concern under traditional stabilization. Because of these advantages a Z-stabilization pathway can be a candidate of practical mitigation strategies as treated in Part 2.

  8. A review of the various techniques of soil rehabilitation in a rural environment following an accidental atmospheric release from a nuclear plant

    International Nuclear Information System (INIS)

    Laylavoix, F.; Madelmont, C.; Fache, P.; Manesse, D.; Camus, H.

    1989-01-01

    A critical survey of the various rehabilitation methods is presented: mechanical cleanup, physico-chemical treatment, new direction of productions. Particular attention has been paid to the qualification of methods: equipment availability, decontamination efficiency, utilization and maintenance conditions. Two appendices are included: the former presents the broad scope of the RESSAC program (Rehabilitation of Soils and Surfaces following an Accident); the latter a review of the information available on the interventions on the CHERNOBYL site environment [fr

  9. Exposure to polycyclic aromatic hydrocarbons in atmospheric PM1.0 of urban environments: Carcinogenic and mutagenic respiratory health risk by age groups.

    Science.gov (United States)

    Agudelo-Castañeda, Dayana M; Teixeira, Elba C; Schneider, Ismael L; Lara, Sheila Rincón; Silva, Luis F O

    2017-05-01

    We investigated the carcinogenic and mutagenic respiratory health risks related to the exposure to atmospheric PAHs in an urban area. Our study focused in the association of these pollutants and their possible effect in human health, principally respiratory and circulatory diseases. Also, we determined a relationship between the inhalation risk of PAHs and meteorological conditions. We validated the hypothesis that in winter PAHs with high molecular weight associated to submicron particles (PM 1 ) may increase exposure risk, especially for respiratory diseases, bronchitis and pneumonia diseases. Moreover, in our study we verified the relationship between diseases and several carcinogenic PAHs (Ind, BbkF, DahA, BaP, and BghiP). These individual PAHs contributed the most to the potential risk of exposure for inhalation of PM 1.0 . Even at lower ambient concentrations of BaP and DahA in comparison with individual concentrations of other PAHs associated to PM 1.0 . Mainly, research suggests to include carcinogenic and mutagenic PAHs in future studies of environmental health risk due to their capacity to associate to PM 10 . Such carcinogenic and mutagenic PAHs are likely to provide the majority of the human exposure, since they originate from dense traffic urban areas were humans congregate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Assessing atmospheric particulate matter distribution based on Saturation Isothermal Remanent Magnetization of herbaceous and tree leaves in a tropical urban environment.

    Science.gov (United States)

    Barima, Yao Sadaiou Sabas; Angaman, Djédoux Maxime; N'gouran, Kobenan Pierre; Koffi, N'guessan Achille; Kardel, Fatemeh; De Cannière, Charles; Samson, Roeland

    2014-02-01

    Particulate matter (PM) emissions, and the associated human health risks, are likely to continue increasing in urban environments of developing countries like Abidjan (Ivory Cost). This study evaluated the potential of leaves of several herbaceous and tree species as bioindicators of urban particulate matter pollution, and its variation over different land use classes, in a tropical area. Four species well distributed (presence frequencies >90%) over all land use classes, easy to harvest and whose leaves are wide enough to be easily scanned were selected, i.e.: Amaranthus spinosus (Amaranthaceae), Eleusine indica (Poaceae), Panicum maximum (Poaceae) and Ficus benjamina (Moraceae). Leaf sampling of these species was carried out at 3 distances from the road and at 3 height levels. Traffic density was also noted and finally biomagnetic parameters of these leaves were determined. Results showed that Saturation Isothermal Remanent Magnetization (SIRM) of leaves was at least 4 times higher (27.5×10(-6)A) in the vicinity of main roads and industrial areas than in parks and residential areas. The main potential sources of PM pollution were motor vehicles and industries. The slightly hairy leaves of the herbaceous plant A. spinosus and the waxy leaves of the tree F. benjamina showed the highest SIRM (25×10(-6)A). Leaf SIRM increased with distance to road (R(2)>0.40) and declined with sampling height (R(2)=0.17). The distance between 0 and 5m from the road seemed to be the most vulnerable in terms of PM pollution. This study has showed that leaf SIRM of herbaceous and tree species can be used to assess PM exposure in tropical urban environments. © 2013.

  11. Remote sensing of aerosol and marine parameters in coastal environments: Exploring the advantage of using polarized radiative transfer simulations of the coupled atmosphere-water system to analyze ocean color measurements

    Science.gov (United States)

    Stamnes, K. H.

    2016-02-01

    Simultaneous retrieval of aerosol and surface properties by means of inverse techniques based on a coupled atmosphere-surface radiative transfer model (CRTM) and optimal estimation can yield a considerable improvement in retrieval accuracy based on radiances measured by MERIS, MODIS, and similar instruments compared with traditional methods. There are uniqueness problems associated with photometric remote sensing measurements (like MERIS/MODIS) that ignore polarization effects, and rely on measuring only the radiance. Use of polarization measurements is particularly important for absorbing aerosols over coastal waters as well as over bright targets such as snow-covered and bare sea ice, where it has proved difficult to retrieve aerosol single-scattering albedo from radiance-only spectrometers such as MERIS and MODIS. We use a vector radiative transfer model for the coupled atmosphere-surface system in conjunction with an optimal estimation/Levenberg-Marquardt method to quantify how polarization measurements can be used to overcome the uniqueness problems associated with radiance-only retrieval of aerosol parameters. However, this study also indicates that even for existing instruments like MERIS and MODIS and future instrument like OLCI, that measure radiance-only, use of a polarized CRTM as a forward model in the optimal estimation can lead to significant enhancement of retrieval capabilities, and facilitate simultaneous retrieval of absorbing aerosols and marine parameters in turbid coastal environments.

  12. Atmospheric Photochemistry

    Science.gov (United States)

    Massey, Harrie; Potter, A. E.

    1961-01-01

    The upper atmosphere offers a vast photochemical laboratory free from solid surfaces, so all reactions take place in the gaseous phase. At 30 km altitude the pressure has fallen to about one-hundredth of that at ground level, and we shall, rather arbitrarily, regard the upper atmosphere as beginning at that height. By a little less than 100 km the pressure has fallen to 10(exp -3) mm Hg and is decreasing by a power of ten for every 15 km increase in altitude. Essentially we are concerned then with the photochemistry of a nitrogen-oxygen mixture under low-pressure conditions in which photo-ionization, as well as photodissociation, plays an important part. Account must also be taken of the presence of rare constituents, such as water vapour and its decomposition products, including particularly hydroxyl, oxides of carbon, methane and, strangely enough, sodium, lithium and calcium. Many curious and unfamiliar reactions occur in the upper atmosphere. Some of them are luminescent, causing the atmosphere to emit a dim light called the airglow. Others, between gaseous ions and neutral molecules, are almost a complete mystery at this time. Similar interesting phenomena must occur in other planetary atmospheres, and they might be predicted if sufficient chemical information were available.

  13. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V

    1973-01-01

    The thermodynamics of the atmosphere is the subject of several chapters in most textbooks on dynamic meteorology, but there is no work in English to give the subject a specific and more extensive treatment. In writing the present textbook, we have tried to fill this rather remarkable gap in the literature related to atmospheric sciences. Our aim has been to provide students of meteorology with a book that can playa role similar to the textbooks on chemical thermodynamics for the chemists. This implies a previous knowledge of general thermodynamics, such as students acquire in general physics courses; therefore, although the basic principles are reviewed (in the first four chapters), they are only briefly discussed, and emphasis is laid on those topics that will be useful in later chapters, through their application to atmospheric problems. No attempt has been made to introduce the thermodynamics of irreversible processes; on the other hand, consideration of heterogeneous and open homogeneous systems permits a...

  14. Short- and medium-chain chlorinated paraffins in air and soil of subtropical terrestrial environment in the pearl river delta, South China: distribution, composition, atmospheric deposition fluxes, and environmental fate.

    Science.gov (United States)

    Wang, Yan; Li, Jun; Cheng, Zhineng; Li, Qilu; Pan, Xiaohui; Zhang, Ruijie; Liu, Di; Luo, Chunling; Liu, Xiang; Katsoyiannis, Athanasios; Zhang, Gan

    2013-03-19

    Research on the environmental fate of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in highly industrialized subtropical areas is still scarce. Air, soil, and atmospheric deposition process in the Pearl River Delta of South China were investigated, and the average SCCP and MCCP concentrations were 5.2 μg/sampler (17.69 ng/m(3)) and 4.1 μg/sampler for passive air samples, 18.3 and 59.3 ng/g for soil samples, and 5.0 and 5.3 μg/(m(2)d) for deposition samples, respectively. Influenced by primary sources and the properties of chlorinated paraffins (CPs), a gradient trend of concentrations and a fractionation of composition from more to less industrialized areas were discovered. Intense seasonal variations with high levels in summer air and winter deposition samples indicated that the air and deposition CP levels were controlled mainly by the vapor and particle phase, respectively. Complex environmental processes like volatilization and fractionation resulted in different CP profiles in different environment matrixes and sampling locations, with C(10-11) C(l6-7) and C(14) C(l6-7), C(10-12) C(l6-7) and C(14) C(l6-8), and C(11-12) C(l6-8) and C(14) C(l7-8) dominating in air, soil, and atmospheric deposition, respectively. Shorter-chain and less chlorinated congeners were enriched in air in the less industrialized areas, while longer-chain and higher chlorinated congeners were concentrated in soil in the more industrialized areas. This is suggesting that the gaseous transport of CPs is the dominant mechanism responsible for the higher concentrations of lighter and likely more mobile CPs in the rural areas.

  15. Atmospheric materiality

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2016-01-01

    A disjunction between the material and the immaterial has been at the heart of the architectural debate for decades. In this dialectic tension, the notion of atmosphere which increasingly claims attention in architectural discourse seems to be parallactic, leading to the re-evaluation of perceptual...... experience and, consequently, to the conceptual and methodological shifts in the production of space, and hence in the way we think about materiality. In this context, architectural space is understood as a contingent construction – a space of engagement that appears to us as a result of continuous...... and complex interferences revealed through our perception; ‘the atmospheric’ is explored as a spatial and affective quality as well as a sensory background, and materiality as a powerful and almost magical agency in shaping of atmosphere. Challenging existing dichotomies and unraveling intrinsic...

  16. Composition of Estonian atmosphere

    International Nuclear Information System (INIS)

    Punning, J. M.; Karindi, A.

    1996-01-01

    Atmospheric study, particularly that of its chemical composition, has a long tradition in Estonia. Since middle of this century, in addition to meteorological observations, some chemical compounds in precipitations have been regularly measured in many meteorological stations. The main aim was to acquire information about the state and dynamics of the atmosphere. Therefore, main attention was paid to monitoring chemical compounds which have a direct impact on the human environment. As energy production developed intensively and SO 2 and NO x increased drastically in the atmosphere in acidic rock areas, like Scandinavia, the problem of acid rain became the most important environmental problem in Europe and North-America. As a consequence, monitoring the compounds of sulphur in precipitation was organized in Estonia. In the 1970 s, as related to large operating oil shale-based power plants, Estonia became a country , where emissions of sulphur compounds per capita were extremely high. In 1979, Estonia became a participant in the European Monitoring and Evaluation Programme - the network created to study transboundary air pollution. The aims of the precipitation chemistry study and the related problems of the formation and transformation of the atmospheric composition have varied over the years. But monitoring of pollutant (in particular, sulphur compound) loads has been a central issue. Over recent years, an attempt was made to estimate the spatial regularities of atmospheric impurities and their impact on the pH of mean monthly precipitations. Furthermore, calculations were provided to find out the origin of atmospheric impurities washed out in Estonia. Until the 1990 s, CO 2 , and some other greenhouse gas (GHG) emissions were not studied in Estonia. The first inventory of GHG for Estonia was provided in 1995 using the Intergovernmental Panel on Climate Change (IPCC) methodology

  17. Space Environment Modeling

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes presentation materials and outputs from operational space environment models produced by the NOAA Space Weather Prediction Center (SWPC) and...

  18. Atomic and Molecular Processes in Atmospheric Environments

    Science.gov (United States)

    1971-04-28

    Van der Graaff accelerator through a thin fo.’lo We have calculated the cross section for 7* this process for 0’ ions. This w: 11 provide the... generated curves calculated tor many assumed values of the rate constants. Physical consistency requires two equilibrium constants (hydration n xi...results have generally confirmed the previous results, i.e., with the alkaline earth atoms, charge transfer leaving an atomic ion strongly dominates over

  19. Atmospheric pollution. Introduction; Pollution atmospherique. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Elichegaray, Ch. [Agence de l' Environnement et de la Maitrise de l' Energie, 75 - Paris (France)

    2006-07-15

    This article is a general introduction to air pollution. It focusses on air quality problems at the local and regional scale: 1 - atmospheric environment and determining factors of its quality; 2 - French situation; 3 - local scale impacts: health hazards; 4 - regional scale impacts: risks for health and ecosystems (acid rains, photochemical pollution); 5 - management of the atmospheric environment (national scale, international scale: monitoring of air quality and role of the French agency of environment and energy mastery - Ademe). (J.S.)

  20. Alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2014-01-01

    of the body and the environment in conjunction with our internalised perception of the habituated background. By actively controlling the sounds built into Kidkit, the child can habituate them through a process of synchronising them with her own bodily rhythms. Hereby the child can establish, in advance...

  1. Atmospheric Smell

    DEFF Research Database (Denmark)

    Stenslund, Anette

    revealed how a museum-staged hospital atmosphere of an art installation was directly addressed owing to its smell. Curiously, this observation speaks against prevailing literature portraying smell as the ‘mute sense’, and what is more, the museum display did not alter smell curatorially. Rather, smell......, hospital-based and museum-staged. Prompted by the ambition to acknowledge the museum’s need to have its activities rooted in thorough investigation of the given culture on show, the dual analytical disposition is a sine qua non spanning varied fields and disciplines. The conceptual discussion offered...... in the thesis is spurred on by philosophical phenomenology predominantly paired with sociological and anthropological theory. It finds support in empirical work from both a hospital and a museum setting. Thus, it draws on a three-month ethnographic fieldwork conducted in 2012 in a Danish hospital, including...

  2. Atmospheric Models/Global Atmospheric Modeling

    Science.gov (United States)

    1998-09-30

    Atmospheric Models /Global Atmospheric Modeling Timothy F. Hogan Naval Research Laboratory Monterey, CA 93943-5502 phone: (831) 656-4705 fax: (831...to 00-00-1998 4. TITLE AND SUBTITLE Atmospheric Models /Global Atmospheric Modeling 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...initialization of increments, improved cloud prediction, and improved surface fluxes) have been transition to 6.4 (Global Atmospheric Models , PE 0603207N, X-0513

  3. Atmospheres in a Test Tube

    Science.gov (United States)

    Claudi, R.; Erculiani, M. S.; Giro, E.; D'Alessandro, M.; Galletta, G.

    2013-09-01

    The "Atmosphere in a Test Tube" project is a laboratory experiment that will be able to reproduce condition of extreme environments by means of a simulator. These conditions span from those existing inside some parts of the human body to combinations of temperatures, pressures, irradiation and atmospheric gases present on other planets. In this latter case the experiments to be performed will be useful as preliminary tests for both simulation of atmosphere of exoplanets and Solar System planets and Astrobiology experiments that should be performed by planetary landers or by instruments to be launched in the next years. In particular at INAF Astronomical Observatory of Padova Laboratory we are approaching the characterization of extrasolar planet atmospheres taking advantage by innovative laboratory experiments with a particular focus on low mass Neptunes and Super earths and low mass M dwarfs primaries.

  4. Titan Buoyant Atmospheric Glider, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Your mission is to explore the atmosphere and surface of Saturn's moon, Titan, a cold, harsh environment that poses many technical challenges for any potential...

  5. Late-Holocene environment and climatic changes in Ameralik Fjord, southwest Greenland: evidence from the sedimentary record

    DEFF Research Database (Denmark)

    Møller, Henrik S.; Jensen, Karin G.; Kuijpers, Antoon

    2006-01-01

      Sedimentological and geochemical (XRF) data together with information from diatom and benthic foraminifera records of a 3.5 m long gravity core from Ameralik fjord, southern West Greenland, is used for reconstructing late Holocene environmental changes in this area. The changes are linked...... to large-scale North Atlantic ocean and climate variability. AMS 14C-dating of benthic foraminifera indicates that the sediment core covers the last 4400 years and may include the termination of the Holocene Thermal Maximum (HTM). The late HTM (4.4-3.2 ka BP) is characterized by high accumulation rates...... conditions were further characterised by limited sea ice probably related to a mild and relatively windy winter climate. After 3.2 ka BP lower fine-grained sedimentation rates, but a larger input from sea-ice rafted or aeolian coarse material prevailed. This can be related to colder atmospheric conditions...

  6. Organic chemistry in the atmosphere. [laboratory modeling of Titan atmosphere

    Science.gov (United States)

    Sagan, C.

    1974-01-01

    The existence of an at least moderately complex organic chemistry on Titan is stipulated based on clear evidence of methane, and at least presumptive evidence of hydrogen in its atmosphere. The ratio of methane to hydrogen is the highest of any atmosphere in the solar system. Irradiation of hydrogen/methane mixtures produces aromatic and aliphatic hydrocarbons. A very reasonable hypothesis assumes that the red cloud cover of Titan is made of organic chemicals. Two-carbon hydrocarbons experimentally produced from irradiated mixtures of methane, ammonia, water, and hydrogen bear out the possible organic chemistry of the Titanian environment.

  7. Solar/Space Environment Data (Satellites)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) monitors the geospace and solar environments using a variety of space weather sensors aboard its fleet of...

  8. Atmosphere: Power, Critique, Politics

    DEFF Research Database (Denmark)

    Albertsen, Niels

    2016-01-01

    This paper hans three interrelated parts. First, atmosphere is approached through the concept of power. Atmospheres 'grip' us directly or mediate power indirectly by manipulating moods and evoking emotions. How does atmosphere relate to different conceptions of power? Second, atmospheric powers may...... be critiqued. Which conception of critique can be involved? Third, critiquing atmospheric powers can generate political conflict. How does atmospheric disputes relate to conceptions of politics and the political?...

  9. Atmospheric Plasma Blade for Surgical Purposes

    Science.gov (United States)

    Oksuz, Lutfi; Yurdabak Karaca, Gozde; Özkaptan, Emir; Uygun, Emre; Uygun Oksuz, Aysegul

    2017-10-01

    Atmospheric plasma cut is a process at the minimum level due to the ions, radicals and free electrons generated by the active electrode and target tissue. Atmospheric plasma cutting devices provide significant advantages as a non-contact electrocautery system that can operate in isotonic environment. During operations where plasma cutting is applied, bleeding is controlled and the side effects that would create the isotonic environment are eliminated. In this study in vivo and in vitro studies will be carried out by producing and optimizing the atmospheric plasma blade. Once the optimum parameters of the instrument are determined, in vivo studies will be performed and the pathology results will be evaluated.

  10. Atmospheric radiation flight dose rates

    Science.gov (United States)

    Tobiska, W. K.

    2015-12-01

    Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

  11. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.H.; Cavalli, F.

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  12. Environmental aspects: - Atmospheric, - aquatic, - terrestrial dispersion of radionuclides

    International Nuclear Information System (INIS)

    Kirchmann, R.

    1982-01-01

    After general introductory remarks the paper deals with the dispersion of radionuclides in the atmosphere and in the aquatic environment as well as with the transfer through the terrestrial environment. (RW)

  13. Mobile Instruments Measure Atmospheric Pollutants

    Science.gov (United States)

    2009-01-01

    As a part of NASA's active research of the Earth s atmosphere, which has included missions such as the Atmospheric Laboratory of Applications and Science (ATLAS, launched in 1992) and the Total Ozone Mapping Spectrometer (TOMS, launched on the Earth Probe satellite in 1996), the Agency also performs ground-based air pollution research. The ability to measure trace amounts of airborne pollutants precisely and quickly is important for determining natural patterns and human effects on global warming and air pollution, but until recent advances in field-grade spectroscopic instrumentation, this rapid, accurate data collection was limited and extremely difficult. In order to understand causes of climate change and airborne pollution, NASA has supported the development of compact, low power, rapid response instruments operating in the mid-infrared "molecular fingerprint" portion of the electromagnetic spectrum. These instruments, which measure atmospheric trace gases and airborne particles, can be deployed in mobile laboratories - customized ground vehicles, typically - to map distributions of pollutants in real time. The instruments must be rugged enough to operate rapidly and accurately, despite frequent jostling that can misalign, damage, or disconnect sensitive components. By measuring quickly while moving through an environment, a mobile laboratory can correlate data and geographic points, revealing patterns in the environment s pollutants. Rapid pollutant measurements also enable direct determination of pollutant sources and sinks (mechanisms that remove greenhouse gases and pollutants), providing information critical to understanding and managing atmospheric greenhouse gas and air pollutant concentrations.

  14. Effects of atmospheric VPD, plant canopies, and low-water years on leaf stomatal conductance and photosynthetic water use efficiency in fifteen potential crop species for use in arid environments

    Science.gov (United States)

    Lue, A.; Jasoni, R. L.; Arnone, J.

    2011-12-01

    When evaluating the potential for growing alternative crop species in arid environments, high vapor pressure deficits (VPDs) that could potentially inhibit crop productivity by limiting stomatal conductance and CO2 uptake must be considered. The objective of this study was to quantify the effects of VPD and irrigation levels on leaf stomatal conductance (gs) and photosynthetic water use efficiency (PWUE) for a range of alternative crop species for aridland agriculture. We evaluated fifteen alternative crops in a field trial in the northern Nevada Walker River Basin. Plots of each species were subjected to two irrigation treatments, 4 and 2 acre-feet per growing season, to simulate normal-year and dry-year irrigation levels. We quantified gs and photosynthesis (A) under decreasing relative humidity (RH) (increasing VPDs) in 10% increments, from about 75% to 2%. About seventeen leaves per species were measured throughout the 2010 growing season over eleven days of samplings. Canopy air temperature and RH were logged in experimental plots to calculate diel and seasonal patterns in canopy VPD. Volumetric water content was also collected to quantify the effects of irrigation treatments on soil moisture and leaf gas exchange. Species varied in their gs and PWUE responses to increasing VPD. Stomatal conductance (gs) of leaves of all species generally increased initially as RH was lowered but then decreased at differing rates as RH dropped further. Average gs (across all measurement VPDs), maximum gs, maximum PWUE, and corresponding VPDs differed among species and between irrigation treatments. Some species (Medicago sativa, Leymus racemosus) showed higher gs across the range of measurement VPDs than other species (Bothrichloa ischaemum, Sorghastrum nutans), while some species exhibited maximum gs and maximum PWUE at higher VPDs (Erograstis tef, Calamovilfa longifolia) than other species (Leymus cinereus, Sorghastrum nutans). These results suggest that some species may

  15. Problems in global atmospheric chemistry

    Science.gov (United States)

    Crutzen, Paul J.

    1993-02-01

    The chemistry of the atmosphere is substantially influenced by a wide range of chemical processes which are primarily driven by the action of ultraviolet radiation of wavelengths shorter than 320 nm (UV-B) on ozone and water vapor. This leads to the formation of hydroxyl (OH) radicals which, despite very low tropospheric concentrations, remove most gases that are emitted into the atmosphere by natural and anthropogenic processes. Therefore, although only about 10% of all atmospheric ozone is located in the troposphere, through the formation of OH, it determines the oxidation efficiency of the atmosphere and is, therefore, of the utmost importance for maintaining its chemical composition. Due to a variety of human activities, especially through increasing emissions of CH4, CO, and NOx, the concentrations of tropospheric ozone and hydroxyl are expected to be increasing in polluted and decreasing in clean tropospheric environments. Altogether, this may be leading to an overall decrease in the oxidation efficiency of the atmosphere, contributing to a gradual buildup of several longlived trace gases that are primarily removed by reaction with OH. In the stratosphere, especially due to catalytic reactions of chlorine-containing gases of industrial origin, ozone is being depleted, most drastically noted during the early spring months over Antarctica. Because ozone is the only atmospheric constituent that can significantly absorb solar radiation in the wavelength region 240 - 320 nm, this loss of ozone enhances the penetration of biologically harmful UV-B radiation to the earth's surface with ensuing negative consequences for the biosphere. Several of the aforementioned chemically active trace gases with growing trends in the atmosphere are also efficient greenhouse gases. Together they can exert a warming effect on the earth's climate about equal to that of carbon dioxide.

  16. Components of the environment

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    This report of the Ministry of the Environment of the Slovak Republic deals with the components of the environment. The results of monitoring of air (emission situation), ambient air quality, atmospheric precipitation, tropospheric ozone, water (surface water, groundwater resources, waste water and drinking water), geological factors (geothermal energy, fuel deposits, ore deposits, non-metallic ore deposits), soil (area statistics, soil contamination. soil reaction and active extractable aluminium, soil erosion), flora and fauna (national strategy of biodiversity protection) are presented

  17. Atmospheric composition change: Ecosystems–Atmosphere interactions

    DEFF Research Database (Denmark)

    Fowler, D.; Pilegaard, Kim; Sutton, M.A.

    2009-01-01

    Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O3, CH4, N2O and particles...

  18. Atmospheric composition change: Ecosystems-Atmosphere interactions

    NARCIS (Netherlands)

    Fowler, D.; Pilegaard, K.; Sutton, M.A.; Ambus, P.; Raivonen, M.; Duyzer, J.; Simpson, D.; Fagerli, H.; Fuzzi, S.; Schjoerring, J.K.; Granier, C.; Neftel, A.; Isaksen, I.S.A.; Laj, P.; Maione, M.; Monks, P.S.; Burkhardt, J.; Daemmgen, U.; Neirynck, J.; Personne, E.; Wichink Kruit, R.J.; Butterbach-Bahl, K.; Flechard, C.; Tuovinen, J.P.; Coyle, M.; Gerosa, G.; Loubet, B.; Altimir, N.; Gruenhage, L.; Ammann, C.; Cieslik, S.; Paoletti, E.; Mikkelsen, T.N.; Ro-Poulsen, H.; Cellier, P.; Cape, J.N.; Horvath, L.; Loreto, F.; Niinemets, U.; Palmer, P.I.; Rinne, J.; Misztal, P.; Nemitz, E.; Nilsson, D.; Pryor, S.; Gallagher, M.W.; Vesala, T.; Skiba, U.; Brueggemann, N.; Zechmeister-Boltenstern, S.; Williams, J.; O'Dowd, C.; Facchini, M.C.; Leeuw, de G.; Flossman, A.; Chaumerliac, N.; Erisman, J.W.

    2009-01-01

    Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O-3, CH4, N2O and particles

  19. Geospace Environment Modeling Program

    Science.gov (United States)

    Dusenbery, Paul B.; Siscoe, George L.

    1992-02-01

    The geospace environment encompasses the highest and largest of the four physical geospheres—lithosphere, hydrosphere, atmosphere, and magnetosphere. Despite its size, its far-reaching structures interconnect and move together in a choreography of organized dynamics, whose complexity is reflected in the intricate movements of the northern lights. The vastness and inaccessibility of geospace, encompassing the plasma environment of the magnetosphere/ionosphere system, and the invisibility of its structures pose great challenges to scientists who want to study its dynamics by obtaining, in effect, video tapes of its globally organized motions. A key component of their strategy is the ability to see nearly all of geospace imaged onto the top of the atmosphere. The geomagnetic field threads the volume of geospace and transmits action, TV-like, from the magnetospheric stage down its lines of force onto the atmospheric screen.

  20. 2004 Environment Industry

    Science.gov (United States)

    2004-01-01

    International: Encana Oil, Quito, Ecuador Futuro Latinamericano, Quito, Ecuador US Embassy, Quito, Ecuador Ecuador Ministry of the Environment... Mexico are among the five largest countries releasing carbon into the atmosphere due to deforestation.l ix This deforestation reduces the Earth’s...www.sdtc.ca/ en /. xlvi Ibid. 33

  1. A Model of the Primordial Lunar Atmosphere

    Science.gov (United States)

    Saxena, Prabal; Elkins-Tanton, Lindy; Petro, Noah; Mandell, Avi

    2017-01-01

    We create the first quantitative model for the early lunar atmosphere, coupled with a magma ocean crystallization model. Immediately after formation, the moon's surface was subject to a radiative environment that included contributions from the early Sun, a post-impact Earth that radiated like a mid-type M dwarf star, and a cooling global magma ocean. This radiative environment resulted in a largely Earth-side atmosphere on the Moon, ranging from approximately 10(exp 4) to approximately 10(exp 2) pascals, composed of heavy volatiles (Na and SiO). This atmosphere persisted through lid formation and was additionally characterized by supersonic winds that transported significant quantities of moderate volatiles and likely generated magma ocean waves. The existence of this atmosphere may have influenced the distribution of some moderate volatiles and created temperature asymmetries which influenced ocean flow and cooling. Such asymmetries may characterize young, tidally locked rocky bodies with global magma oceans and subject to intense irradiation.

  2. Planetary Atmospheric Electricity

    CERN Document Server

    Leblanc, F; Yair, Y; Harrison, R. G; Lebreton, J. P; Blanc, M

    2008-01-01

    This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to t...

  3. Our shared atmosphere

    Science.gov (United States)

    Our atmosphere is a precious and fascinating resource, providing air to breath, shielding us from harmful ultraviolet radiation (UV), and maintaining a comfortable climate. Since the industrial revolution, people have significantly altered the composition of the atmosphere throu...

  4. Effect of Atmospheric Conditions on LIBS Spectra

    Directory of Open Access Journals (Sweden)

    Andrew J. Effenberger

    2010-05-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS is typically performed at ambient Earth atmospheric conditions. However, interest in LIBS in other atmospheric conditions has increased in recent years, especially for use in space exploration (e.g., Mars and Lunar or to improve resolution for isotopic signatures. This review focuses on what has been reported about the performance of LIBS in reduced pressure environments as well as in various gases other than air.

  5. Influence of atmospheric turbulence on Lidar performance

    Science.gov (United States)

    Chai, Guo-bei; Sun, Xiao; Yang, Jian; Yang, Wen-fu; Bao, Wen-zhuo; Xie, Xiao-yang

    2017-11-01

    In the interference analysis of LIDAR system, atmospheric turbulence model is indispensable. To improve the accuracy of atmospheric effects in the LADAR simulator, Exponential Weibull model is adopted to calculate atmospheric turbulence, achieving a physically-based simulation of a LADAR system integrated with quantitative atmospheric turbulence. The feasibility of the proposed method is verified by comparing simulated and field data. To evaluate LIDAR performance in complex environments, the method of analyzing the system performance based on a general simulation framework is proposed. A general and systematic physically reasonable imaging LADAR simulation model combining "laser - target - atmosphere: LADAR imaging" is achieved for assessment of LADAR imaging system. Experimental results show that the turbulence can cause energy dispersion, leading to the detection of false alarm

  6. Atmospheric water harvester

    African Journals Online (AJOL)

    2017-09-10

    Sep 10, 2017 ... ... involve condensation and precipitation. So, in order to examine the potential water in the atmosphere, atmospheric water harvester model was developed since it is one of the sustainable alternative water resources [6]. Normally, the atmosphere contains water in the form of water vapor, moisture and so ...

  7. Atmospheric refraction : a history

    NARCIS (Netherlands)

    Lehn, WH; van der Werf, S

    2005-01-01

    We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of

  8. Atmospheric Sampling of Microorganisms with UAS

    Science.gov (United States)

    Schmale, D. G., III

    2017-12-01

    Many microorganisms relevant to crops, domestic animals, and humans are transported over long distances through the atmosphere. Some of these atmospheric microbes catalyze the freezing of water at higher temperatures and facilitate the onset of precipitation. A few have crossed continents. New technologies are needed to study the movement of microorganisms in the atmosphere. We have used unmanned aircraft systems (UAS) to study the transport of microorganisms tens to hundreds of meters above the ground. These UAS are equipped with unique devices for collecting microbes in the atmosphere during flight. Autonomous systems enable teams of UAS to perform complex atmospheric sampling tasks, and coordinate flight missions with one another. Data collected with UAS can be used to validate and improve disease forecasting models along highways in the sky, connecting transport scales across farms, states, and continents. Though terrestrial environments are often considered a major contributor to atmospheric microbial aerosols, little is known about aquatic sources of microbial aerosols. Droplets containing microorganisms can aerosolize from the water surface, liberating them into the atmosphere. We are using teams of unmanned surface vehicles (USVs) and UAS to study the aerosolization of microbes from aquatic environments. Controlled flume studies using highspeed video have allowed us to observe unique aerosolization phenomena that can launch microbes out of the water and into the air. Unmanned systems may be used to excite the next generation of biologists and engineers, and raise important ethical considerations about the future of human-robot interactions.

  9. Fair weather atmospheric electricity

    International Nuclear Information System (INIS)

    Harrison, R G

    2011-01-01

    Not long after Franklin's iconic studies, an atmospheric electric field was discovered in 'fair weather' regions, well away from thunderstorms. The origin of the fair weather field was sought by Lord Kelvin, through development of electrostatic instrumentation and early data logging techniques, but was ultimately explained through the global circuit model of C.T.R. Wilson. In Wilson's model, charge exchanged by disturbed weather electrifies the ionosphere, and returns via a small vertical current density in fair weather regions. New insights into the relevance of fair weather atmospheric electricity to terrestrial and planetary atmospheres are now emerging. For example, there is a possible role of the global circuit current density in atmospheric processes, such as cloud formation. Beyond natural atmospheric processes, a novel practical application is the use of early atmospheric electrostatic investigations to provide quantitative information on past urban air pollution.

  10. Pluto's atmosphere near perihelion

    International Nuclear Information System (INIS)

    Trafton, L.M.

    1989-01-01

    A recent stellar occultation has confirmed predictions that Pluto has an atmosphere which is sufficiently thick to uniformly envelope the planet and to extend far above the surface. Pluto's atmosphere consists of methane and perhaps other volatile gases at temperatures below their freezing points; it should regulate the surface temperature of its volatile ices to a globally uniform value. As Pluto approaches and passes through perihelion, a seasonal maximum in the atmospheric bulk and a corresponding minimum in the exposed volatile ice abundance is expected to occur. The lag in maximum atmospheric bulk relative to perihelion will be diagnostic of the surface thermal properties. An estimate of Pluto's atmospheric bulk may result if a global darkening (resulting from the disappearance of the seasonally deposited frosts) occurs before the time of maximum atmospheric bulk. The ice deposited shortly after perihelion may be diagnostic of the composition of Pluto's volatile reservoir

  11. Sources of atmospheric ammonia

    International Nuclear Information System (INIS)

    Harriss, R.C.; Michaels, J.T.

    1982-01-01

    The information available on factors that influence emissions from the principal societal sources of ammonia to the atmosphere, namely combustion processes, volatilization of farm animal wastes, and volatilization of fertilizers, is reviewed. Emission factors are established for each major source of atmospheric ammonia. The factors are then multiplied by appropriate source characterization descriptors to obtain calculated fluxes of ammonia to the atmosphere on a state-by-state basis for the United States

  12. Designing Dynamic Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie; Højlund, Marie

    2012-01-01

    This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful,....... The potentials and implica-­‐ tions are presented through a design case, Kidkit, highlighting temporality as design parametre within interaction design.......This paper addresses the notion of atmospheres from a designerly perspective, and discusses temporal challenges facing interaction designers when acknowledging the dynamic character of it. As atmospheres are created in the relation between body, space, and time, a pragmatic approach seems useful...

  13. Atmospheric Measurements Laboratory (AML)

    Data.gov (United States)

    Federal Laboratory Consortium — The Atmospheric Measurements Laboratory (AML) is one of the nation's leading research facilities for understanding aerosols, clouds, and their interactions. The AML...

  14. Io's tenuous atmosphere

    International Nuclear Information System (INIS)

    Johnson, T.V.; Matson, D.L.

    1989-01-01

    An evaluation is made of observational evidence adduced to date for the various extant models of the Io atmosphere. SO2 and its various photochemical products have been noted to play a major role in the atmosphere; such atomic species as Na and K are present in smaller quantities, and play an important role in the atmosphere's ion chemistry. The vapor pressure equilibrium between condensed SO 2 on the surface and the atmospheric gas is an important factor in the global control of SO 2 gas distribution, but cannot account for the neutral densities at the terminator required for ionospheric models in view of realistic surface temperature distributions

  15. Atmospheric Prebiotic Chemistry and Organic Hazes

    Science.gov (United States)

    Trainer, Melissa G.

    2012-01-01

    Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of pre biotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere.

  16. Geophysical and atmospheric evolution of habitable planets.

    Science.gov (United States)

    Lammer, Helmut; Selsis, Frank; Chassefière, Eric; Breuer, Doris; Griessmeier, Jean-Mathias; Kulikov, Yuri N; Erkaev, Nikolai V; Khodachenko, Maxim L; Biernat, Helfried K; Leblanc, Francois; Kallio, Esa; Lundin, Richard; Westall, Frances; Bauer, Siegfried J; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Gröller, Hannes; Hanslmeier, Arnold; Hausleitner, Walter; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Leitzinger, Martin; Lichtenegger, Herbert I M; Liseau, René; Lunine, Jonathan; Motschmann, Uwe; Odert, Petra; Paresce, Francesco; Parnell, John; Penny, Alan; Quirrenbach, Andreas; Rauer, Heike; Röttgering, Huub; Schneider, Jean; Spohn, Tilman; Stadelmann, Anja; Stangl, Günter; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    The evolution of Earth-like habitable planets is a complex process that depends on the geodynamical and geophysical environments. In particular, it is necessary that plate tectonics remain active over billions of years. These geophysically active environments are strongly coupled to a planet's host star parameters, such as mass, luminosity and activity, orbit location of the habitable zone, and the planet's initial water inventory. Depending on the host star's radiation and particle flux evolution, the composition in the thermosphere, and the availability of an active magnetic dynamo, the atmospheres of Earth-like planets within their habitable zones are differently affected due to thermal and nonthermal escape processes. For some planets, strong atmospheric escape could even effect the stability of the atmosphere.

  17. Charge Transfer Scheme for Atmospheric Ice Sensing

    Directory of Open Access Journals (Sweden)

    Umair Najeeb MUGHAL

    2015-01-01

    Full Text Available The atmospheric icing parameters are being measured nowadays with the aid of more customized yet limited commercial equipment. The parameters include atmospheric ice detection, icing load and icing rate. The robustness of such equipment is usually under scrutiny when it comes to cold/harsh environment operations. This phenomenon was experienced consistently by the atmospheric Icing Research Team at Narvik University College during data retrieval exercises from its atmospheric icing stations installed at Fargnesfjellet during 2012-13. In this paper it is aimed to address the potential feasibility to produce a robust hardware addressing the icing measurements signals, which includes instrumentation hardware giving icing indications, icing type and de- icing rate measurements in a single platform (not commercially available till date.

  18. A Survey of Atmospheric Turbulence Characteristics

    Science.gov (United States)

    1981-08-19

    urban heat island reduced atmospheric stability, especially at lower levels. Turbulence wao more intense in the rougher and less stable urban environment...20546 1 30 Owl DISTRIBUTION (Continued) • No. of A Copies Commander -USAF Environmental Teohnical Applications Center (MAC) ATTNt Mr. Oscar E

  19. Urban atmospheric contamination

    International Nuclear Information System (INIS)

    Baldasano Jose, M.

    1997-01-01

    The problems of contamination are not only limited to this century, pale pathology evidences of the effects of the contamination of the air exist in interiors in the health of the old ones; the article mention the elements that configure the problem of the atmospheric contamination, atmospheric pollutants and emission sources, orography condition and effects induced by the urbanization process

  20. The Power of Atmosphere

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2014-01-01

    composed of bubbles of affects – that is, the particles that are charged with power and normativity. References Grtiffero, T. (2014 (2010)). Atmospheres: Aesthetics of Emotional Spaces. Ashgate Philippopoulos-Mihalopoulos, A. (2013). Atmospheres of law: Senses, affects, lawscapes, in Emotion, Space...

  1. Atmosphere and Heritage

    DEFF Research Database (Denmark)

    Ventzel Riis, Nina

    2012-01-01

    -between of the materials. This is what we identify as atmosphere, an enveloping phenomenon that surrounds and affects our sensuous system and well-being when we approach, enter, stay or move in a building. When we leave the building again we carry this atmospheric multi-sensory experience with us without adequate methods...

  2. Intensifying the Atmospheric

    DEFF Research Database (Denmark)

    Liebst, Lasse Suonperä

    2012-01-01

    understanding of atmospheres as aesthetically ‘radiating’ from the surfaces of space, thinks physiognomically, the article argues for a spatial morphological perspective on atmospheres. Thus, post-phenomeno¬logically, it is argued that the atmospheric given is given by the density of pedestrians, which...... are ‘compressed’ by the spatial morphologies of urban space. In this perspective atmospheres are to be understood as an emergent property that develops when the spatial morphological compression of urban life passes a certain threshold, that is, when the affective rhythm of the urban assemblages becomes...... sufficiently intense. All things considered, the paper should be read as a sociological contribution to theoretically reconstruct the concept of urban atmospheres in the light of spatial morphology....

  3. Titan's Lower Atmosphere

    Science.gov (United States)

    Griffith, Caitlin Ann

    2007-09-01

    Saturn's largest moon, Titan, sports an atmosphere 10 times thicker than Earth's. Like Earth, the moon's atmosphere is N2 based and possesses a rich organic chemistry. In addition, similar to the terrestrial hydrological cycle, Titan has a methane cycle, with methane clouds, rain and seas. Presently, there is a revolution in our understanding of the moon, as data flows in and is analyzed from the NASA and ESA Cassini-Huygens mission. For example, seas were detected only this year. Here I will discuss the evolution of our understanding of Titan's atmosphere, its composition, chemistry, dynamics and origin. Current open questions will also be presented. Studies of Titan's atmosphere began and evolved to the present state in less time than that of a single scientist's career. This short interlude of activity demonstrates the rigors of the scientific method, and raises enticing questions about the workings and evolution of an atmosphere.

  4. Pluto's surface composition and atmosphere

    Science.gov (United States)

    Young, L. A.; Gladstone, R.; Summers, M. E.; Strobel, D. F.; Kammer, J.; Hinson, D. P.; Grundy, W. M.; Cruikshank, D. P.; Protopapa, S.; Schmitt, B.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Ennico Smith, K.

    2017-12-01

    New Horizons studied Pluto's N2-dominated neutral atmosphere through radio (at 4.2 cm with the REX radio experiment), solar and stellar occultations and airglow (at 52-187 nm with the Alice ultraviolet spectrograph), and imaging (with the LORRI and MVIC visible-wavelength cameras). It studied the plasma environment and solar wind interaction with in situ instruments (PEPPSI and SWAP). Contemporaneous observations of Pluto's atmosphere from Earth included a ground-based stellar occultation and ALMA observations of gaseous CO and HCN. Joint analysis of these datasets reveal a variable boundary layer; a stable lower atmosphere; radiative heating and cooling; haze production and hydrocarbon chemistry; diffusive equilibrium; and slower-than-expected escape. New Horizons studied Pluto's surface composition with the LEISA near-infrared spectral imager from 1.25 to 2.5 micron. Additional compositional information at higher spatial resolution came from the MVIC 4-channel color imager, which included a channel centered at 0.89 micron specifically designed to detect solid CH4. These instruments allow mapping of the volatiles N2, CO, and CH4, the surface expression of the H2O bedrock, and the dark, reddish material presumed to be tholins. These observations reveal a large equatorial basin (informally named Sptunik Planitia), filled with N2 ice with minor amounts of CO and CH4, surrounded by hills of CH4 and H2O ice. Broadly speaking, composition outside of Sptunik Planitia follows latitudinal banding, with dark, mainly volatile free terrains near the equator, with N2, CO, and CH4 at mid-northern latitudes, and mainly CH4 at high northern latitudes. Deviations from these broad trends are seen, and point to complex surface-atmosphere interactions at diurnal, seasonal, perennial, and million-year timescales.

  5. The PHOCUS Project: Atmospheric Composition

    Science.gov (United States)

    Hedin, J.; Gumbel, J.; Khaplanov, M.

    2012-12-01

    On the morning of July 21, 2011, the PHOCUS sounding rocket was launched from Esrange, Sweden, into strong noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE). The aim of the PHOCUS project (Particles, Hydrogen and Oxygen Chemistry in the Upper Summer mesosphere) is to study mesospheric particles (ice and meteoric smoke) and their interaction with their neutral and charged environment. Interactions of interest comprise the charging and nucleation of particles, the relationship between meteoric smoke and ice, and the influence of these particles on gas-phase chemistry. Here we will describe the optical measurements of the atmospheric composition and present first results including comparison to the other simultaneous measurements. The atmospheric composition was probed by a set of optical instruments from Stockholm University. The idea behind the instrument setup was to combine the advantages of the sensitive resonance fluorescence with well-calibrated airglow photometry. The set of instruments consisted of two resonance fluorescence probes (each containing a lamp and a detector), one for atomic oxygen and one for atomic hydrogen, and two IR photometers for O2 and OH dayglow emissions in the near IR. The O2 IR Atmospheric system at 1.27 μm is related to the photolysis of O3, which during the day is in steady state with O and a retrieval of O is possible. The OH Meinel emission is produced by the reaction between mesospheric O3 and H, and H concentrations can be deduced by combining information from both photometers. Unfortunately, some of these measurements were corrupted by instrument problems or payload glow. O3 and O profiles will be presented and compared to the simultaneous measurements of ice and meteoric smoke particles, water vapour and the state of the background neutral and charged atmosphere.

  6. 40 CFR 53.22 - Generation of test atmospheres.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2... the method of generation can produce reproducible concentrations, verification is optional. If the...

  7. ARTEAM - Advanced ray tracing with earth atmospheric models

    NARCIS (Netherlands)

    Kunz, G.J.; Moerman, M.M.; Eijk, A.M.J. van

    2002-01-01

    The Advanced Ray Tracing with Earth Atmospheric Models (ARTEAM) aims at a description of the electro-optical propagation environment in the marine atmospheric surface layer. For given meteorological conditions, the model evaluates height- and range-resolved transmission losses, refraction and

  8. Upper-Atmospheric Space and Earth Weather Experiment

    Data.gov (United States)

    National Aeronautics and Space Administration — The USEWX project is seeking to monitor, record, and distribute atmospheric measurements of the radiation environment by installing a variety of dosimeters and other...

  9. Atmospheric pollution and its implications in the Eastern Transvaal highveld

    CSIR Research Space (South Africa)

    Tyson, PD

    1988-04-01

    Full Text Available This report is a review of available information on the dispersion climatology, the degree of atmospheric pollution and the various impacts of that pollution on man and environment in the Eastern Transvaal Highveld (ETH) and adjacent regions...

  10. Atmosphere Impact Losses

    Science.gov (United States)

    Schlichting, Hilke E.; Mukhopadhyay, Sujoy

    2018-02-01

    Determining the origin of volatiles on terrestrial planets and quantifying atmospheric loss during planet formation is crucial for understanding the history and evolution of planetary atmospheres. Using geochemical observations of noble gases and major volatiles we determine what the present day inventory of volatiles tells us about the sources, the accretion process and the early differentiation of the Earth. We further quantify the key volatile loss mechanisms and the atmospheric loss history during Earth's formation. Volatiles were accreted throughout the Earth's formation, but Earth's early accretion history was volatile poor. Although nebular Ne and possible H in the deep mantle might be a fingerprint of this early accretion, most of the mantle does not remember this signature implying that volatile loss occurred during accretion. Present day geochemistry of volatiles shows no evidence of hydrodynamic escape as the isotopic compositions of most volatiles are chondritic. This suggests that atmospheric loss generated by impacts played a major role during Earth's formation. While many of the volatiles have chondritic isotopic ratios, their relative abundances are certainly not chondritic again suggesting volatile loss tied to impacts. Geochemical evidence of atmospheric loss comes from the {}3He/{}^{22}Ne, halogen ratios (e.g., F/Cl) and low H/N ratios. In addition, the geochemical ratios indicate that most of the water could have been delivered prior to the Moon forming impact and that the Moon forming impact did not drive off the ocean. Given the importance of impacts in determining the volatile budget of the Earth we examine the contributions to atmospheric loss from both small and large impacts. We find that atmospheric mass loss due to impacts can be characterized into three different regimes: 1) Giant Impacts, that create a strong shock transversing the whole planet and that can lead to atmospheric loss globally. 2) Large enough impactors (m_{cap} ≳ √{2

  11. Dynamics of Massive Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Chemke, Rei; Kaspi, Yohai, E-mail: rei.chemke@weizmann.ac.il [Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl st., 76100, Rehovot (Israel)

    2017-08-10

    The many recently discovered terrestrial exoplanets are expected to hold a wide range of atmospheric masses. Here the dynamic-thermodynamic effects of atmospheric mass on atmospheric circulation are studied using an idealized global circulation model by systematically varying the atmospheric surface pressure. On an Earth analog planet, an increase in atmospheric mass weakens the Hadley circulation and decreases its latitudinal extent. These changes are found to be related to the reduction of the convective fluxes and net radiative cooling (due to the higher atmospheric heat capacity), which, respectively, cool the upper troposphere at mid-low latitudes and warm the troposphere at high latitudes. These together decrease the meridional temperature gradient, tropopause height and static stability. The reduction of these parameters, which play a key role in affecting the flow properties of the tropical circulation, weakens and contracts the Hadley circulation. The reduction of the meridional temperature gradient also decreases the extraction of mean potential energy to the eddy fields and the mean kinetic energy, which weakens the extratropical circulation. The decrease of the eddy kinetic energy decreases the Rhines wavelength, which is found to follow the meridional jet scale. The contraction of the jet scale in the extratropics results in multiple jets and meridional circulation cells as the atmospheric mass increases.

  12. Reference Atmosphere for Mercury

    Science.gov (United States)

    Killen, Rosemary M.

    2002-01-01

    We propose that Ar-40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere will lead to a smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the Hermean atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. Ar-40 in the atmospheres of the planets is a measure of potassium abundance in the interiors, since Ar-40 is a product of radiogenic decay of K-40 by electron capture with the subsequent emission of a 1.46 eV gamma-ray. Although the Ar-40 in the Earth's atmosphere is expected to have accumulated since the late bombardment, Ar-40 in the atmospheres of Mercury and the Moon is eroded quickly by photoionization and electron impact ionization. Thus, the argon content in the exospheres of the Moon and Mercury is representative of current effusion rather than accumulation over the lifetime of the planet.

  13. Bibliografía sobre organismos, ambientes y procesos marinos y atmosféricos en Bahía Culebra, Pacífico norte, Guanacaste, Costa Rica (1922-2012 Bibliography on marine organisms, environments, and oceanographic and atmospheric processes in Bahía Culebra, north Pacific, Costa Rica (1922-2012

    Directory of Open Access Journals (Sweden)

    Jorge Cortés

    2012-04-01

    Full Text Available Bahía Culebra se locoaliza en la parte norte de la costa Pacífica de Costa Rica. Es una región de afloramiento estacional, rica en ambientes y organismos marinos, y además, la zona de mayor desarrollo turístico del país. En este trabajo compilo y analizo una lista de 182 publicaciones en revista científcas y 23 tesis, informes y libros sobre organismos, ambientes y procesos marinos y atmosféricos en Bahía Culebra o donde se menciona la Bahía, se presentan y analizan. La gran mayoría de los trabajos, empezando en 1922 con la descripción de un poliqueto, son sobre biodiversidad y ecología. Faltan trabajos sobre algunos ambientes de la bahía, por ejemplo, el bentos de los fondos blandos, y grupos de organismos, por ejemplo, sobre gusanos planos de vida libre. Faltan investigaciones sobre pesquería y manejo de los organismos y ambientes marinos de la Bahía.Bibliography on marine organisms, environments, and oceanographic and atmospheric processes in Bahía Culebra, north Pacific, Costa Rica (1922-2012. Bahía Culebra is located on the north Pacific coast of Costa Rica. It is a seasonal upwelling area, rich in marine ecosystems and organisms, and the main tourist development area in the country. Here, I compiled and analyzed a list of 182 publications in scientific journals, and 23 thesis, reports and books in which marine organisms, environments and marine and atmospheric processes from Bahía Culebra or in which the Bay are mentioned is presented and analyzed. The majority of the publications, starting with a paper from 1922 on a polychaete worm, are on biodiversity and ecology. The are no publications on some environments, for example the benthonic fauna of soft bottoms, or on some taxa, for example, flat worms. More work is needed on fisheries and management of the organisms and environments of Bahía Culebra.

  14. New atmospheric program

    Science.gov (United States)

    The National Science Foundation's Division of Atmospheric Sciences has established an Upper Atmospheric Facilities program within its Centers and Facilities section. The program will support the operation of and the scientific research that uses the longitudinal chain of incoherent scatter radars. The program also will ensure that the chain is maintained as a state-of-the-art research tool available to all interested and qualified scientists.For additional information, contact Richard A. Behnke, Division of Atmospheric Sciences, National Science Foundation, 1800 G Street, N.W., Washington, DC 20550 (telephone: 202-357-7390).

  15. Comments on "Modified wind chill temperatures determined by a whole body thermoregulation model and human-based convective coefficients" by Ben Shabat, Shitzer and Fiala (2013) and "Facial convective heat exchange coefficients in cold and windy environments estimated from human experiments" by Ben Shabat and Shitzer (2012)

    Science.gov (United States)

    Osczevski, Randall J.

    2014-08-01

    Ben Shabat et al. (Int J Biometeorol 56(4):639-51, 2013) present revised charts for wind chill equivalent temperatures (WCET) and facial skin temperatures (FST) that differ significantly from currently accepted charts. They credit these differences to their more sophisticated calculation model and to the human-based equation that it used for finding the convective heat transfer coefficient (Ben Shabat and Shitzer, Int J Biometeorol 56:639-651, 2012). Because a version of the simple model that was used to create the current charts accurately reproduces their results when it uses the human-based equation, the differences that they found must be entirely due to this equation. In deriving it, Ben Shabat and Shitzer assumed that all of the heat transfer from the surface of their cylindrical model was due to forced convection alone. Because several modes of heat transfer were occurring in the human experiments they were attempting to simulate, notably radiation, their coefficients are actually total external heat transfer coefficients, not purely convective ones, as the calculation models assume. Data from the one human experiment that used heat flux sensors supports this conclusion and exposes the hazard of using a numerical model with several adjustable parameters that cannot be measured. Because the human-based equation is faulty, the values in the proposed charts are not correct. The equation that Ben Shabat et al. (Int J Biometeorol 56(4):639-51, 2013) propose to calculate WCET should not be used.

  16. The origin of atmosphere

    International Nuclear Information System (INIS)

    Marx, Gy.

    1975-01-01

    The evolution of the atmosphere of the Earth is described. Starting from the hot Universe the main steps of the ''cooling-down'' process as the different states of the condensation of the matter are discussed. After this nuclear evolution the chemical evolution could start on the solid Earth's crust. In the reductive primordial atmosphere mainly due to ultraviolet rays the basic molecules for life as sugars and amino acids were formed. The photosynthesis of the plants has later produced the oxygen being present in the recent atmosphere. The question whether the pollution could affect the auto-stabilization loop of the atmosphere is also discussed. Finally the possibility of life on the Mars is studied. (Sz.Z.)

  17. Atmospheric Heavy Metal Pollution

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 4. Atmospheric Heavy Metal Pollution - Development of Chronological Records and Geochemical Monitoring. Rohit Shrivastav. General Article Volume 6 Issue 4 April 2001 pp 62-68 ...

  18. The invention of atmosphere.

    Science.gov (United States)

    Martin, Craig

    2015-08-01

    The word "atmosphere" was a neologism Willebrord Snellius created for his Latin translation of Simon Stevin's cosmographical writings. Astronomers and mathematical practitioners, such as Snellius and Christoph Scheiner, applying the techniques of Ibn Mu'ādh and Witelo, were the first to use the term in their calculations of the height of vapors that cause twilight. Their understandings of the atmosphere diverged from Aristotelian divisions of the aerial region. From the early years of the seventeenth century, the term was often associated with atomism or corpuscular matter theory. The concept of the atmosphere changed dramatically with the advent of pneumatic experiments in the middle of the seventeenth century. Pierre Gassendi, Walter Charleton, and Robert Boyle transformed the atmosphere of the mathematicians giving it the characteristics of weight, specific gravity, and fluidity, while disputes about its extent and border remained unresolved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Photosynthesis in Hydrogen-Dominated Atmospheres

    OpenAIRE

    Bains, William; Seager, Sara; Zsom, Andras

    2014-01-01

    The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H[subscript 2]-dominated atmosphere. If a rocky, H[subscript 2]-dominated planet harbors life, th...

  20. High Pressure Atmospheric Sampling Inlet System for Venus or the Gas Giants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized high pressure atmospheric sampling inlet system for sample acquisition in extreme planetary environments,...

  1. Global atmospheric changes.

    OpenAIRE

    Piver, W T

    1991-01-01

    Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the proces...

  2. Intensifying the Atmospheric

    DEFF Research Database (Denmark)

    Liebst, Lasse Suonperä

    2012-01-01

    The phenomenological concept of urban atmospheres is more often applied as an aesthetic description of the metropolitan space as such. This conceptualization is supported in this paper; however, I strive to give the concept a post-phenomenological axial turn. While phenomenology, due to its under...... sufficiently intense. All things considered, the paper should be read as a sociological contribution to theoretically reconstruct the concept of urban atmospheres in the light of spatial morphology....

  3. Dynamics in Atmospheric Physics

    Science.gov (United States)

    Lindzen, Richard A.

    2005-08-01

    Motion is manifest in the atmosphere in an almost infinite variety of ways. In Dynamics in Atmospheric Physics, Dr. Richard Lindzen describes the nature of motion in the atmosphere, develops fluid dynamics relevant to the atmosphere, and explores the role of motion in determining the climate and atmospheric composition. The author presents the material in a lecture note style, and the emphasis throughout is on describing phenomena that are at the frontiers of current research, but due attention is given to the methodology of research and to the historical background of these topics. The author's treatment and choice of topics is didactic. Problems at the end of each chapter will help students assimilate the material. In general the discussions emphasize physical concepts, and throughout Dr. Lindzen makes a concerted effort to avoid the notion that dynamic meteorology is simply the derivation of equations and their subsequent solution. His desire is that interested students will delve further into solution details. The book is intended as a text for first year graduate students in the atmospheric sciences. Although the material in the book is self contained, a familiarity with differential equations is assumed; some background in fluid mechanics is helpful.

  4. Atmospheric Models for Aerocapture

    Science.gov (United States)

    Justus, C. G.; Duvall, Aleta L.; Keller, Vernon W.

    2004-01-01

    There are eight destinations in the solar System with sufficient atmosphere for aerocapture to be a viable aeroassist option - Venus, Earth, Mars, Jupiter, Saturn and its moon Titan, Uranus, and Neptune. Engineering-level atmospheric models for four of these targets (Earth, Mars, Titan, and Neptune) have been developed for NASA to support systems analysis studies of potential future aerocapture missions. Development of a similar atmospheric model for Venus has recently commenced. An important capability of all of these models is their ability to simulate quasi-random density perturbations for Monte Carlo analyses in developing guidance, navigation and control algorithm, and for thermal systems design. Similarities and differences among these atmospheric models are presented, with emphasis on the recently developed Neptune model and on planned characteristics of the Venus model. Example applications for aerocapture are also presented and illustrated. Recent updates to the Titan atmospheric model are discussed, in anticipation of applications for trajectory and atmospheric reconstruct of Huygens Probe entry at Titan.

  5. Radiation environment at Kalpakkam

    International Nuclear Information System (INIS)

    Iyengar, M.A.R.

    1989-01-01

    Nuclear facilities located at Kalpakkam in Tamil Nadu State of India include at present nuclear power reactors, a fast breeder reactor, a nuclear research centre and a waste management facility. Active wastes generated at the site are collected, treated and safely disposed. High-level wastes are stored underground in RCC trenches and tile hole and low-level wastes in the from of liquid effluents are discharged into the sea. Off-gases are dispersed through stacks in the atmosphere. Environmental survey laboratory established at the site in 1974 carries out radiation surveillance of the environment, evaluates radiological impacts on environment and public, and assesses radiation exposure of the population. It is observed that even after five years of operation of the nuclear power station, radioactivity and radiation levels in the environment have virtually remained at the pre-operational levels. (M.G.B.). 14 figs., 4 tabs

  6. Dispersion of effluents in the atmosphere; Dispersion des effluents dans l`atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This conference day was organized by the `convection` section of the French association of thermal engineers with the support of the environment and energy mastery agency (ADEME). This book of proceedings contains 10 papers entitled: `physical modeling of atmospheric dispersion in wind tunnels. Some industrial examples`; `modeling of the noxious effects of a fire on the environment of an industrial site: importance of thermal engineering related hypotheses`; `atmospheric diffusion of a noxious cloud: fast evaluation method of safety areas around refrigerating installations that use ammonia`; `modeling of atmospheric flows in urban areas in order to study the dispersion of pollutants`; `use of a dispersion parameter to characterize the evolution of a diffusion process downstream of a linear source of passive contaminant placed inside a turbulent boundary layer`; `elements of reflexion around the development of an analytical methodology applied to the elaboration of measurement strategies of air quality in ambient and outdoor atmospheres around industrial sites`; `state-of-the-art about treatment techniques for VOC-rich gaseous effluents`; `characteristics of the time variation of the atmospheric pollution in the Paris region and visualization of its space distribution`; `mass-spectrometry for the measurement of atmospheric pollutants`; `volume variations in natural convection turbulence`. (J.S.)

  7. IRST infrared background analysis of bay environments

    CSIR Research Space (South Africa)

    Schwering, PBW

    2008-04-01

    Full Text Available threats can be present in environments with cluttered backgrounds as well as rapidly varying atmospheric conditions. During trials executed in False Bay a large amount of target, background and atmosphere data was gathered that is of use in analysis...

  8. CO2 Virtual Science Data Environment API

    Data.gov (United States)

    National Aeronautics and Space Administration — The CO2 Virtual Data Environment is a comprehensive effort at bringing together the models, data, and tools necessary to perform research on atmospheric CO2.This...

  9. The atmosphere and climate of Mars

    CERN Document Server

    Clancy, R Todd; Forget, François; Smith, Michael D; Zurek, Richard W

    2017-01-01

    Humanity has long been fascinated by the planet Mars. Was its climate ever conducive to life? What is the atmosphere like today and why did it change so dramatically over time? Eleven spacecraft have successfully flown to Mars since the Viking mission of the 1970s and early 1980s. These orbiters, landers and rovers have generated vast amounts of data that now span a Martian decade (roughly eighteen years). This new volume brings together the many new ideas about the atmosphere and climate system that have emerged, including the complex interplay of the volatile and dust cycles, the atmosphere-surface interactions that connect them over time, and the diversity of the planet's environment and its complex history. Including tutorials and explanations of complicated ideas, students, researchers and non-specialists alike are able to use this resource to gain a thorough and up-to-date understanding of this most Earth-like of planetary neighbours.

  10. BIOSIGNATURE GASES IN H2-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS

    International Nuclear Information System (INIS)

    Seager, S.; Bains, W.; Hu, R.

    2013-01-01

    Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H 2 -dominated atmospheres. We study biosignature gases on exoplanets with thin H 2 atmospheres and habitable surface temperatures, using a model atmosphere with photochemistry and a biomass estimate framework for evaluating the plausibility of a range of biosignature gas candidates. We find that photochemically produced H atoms are the most abundant reactive species in H 2 atmospheres. In atmospheres with high CO 2 levels, atomic O is the major destructive species for some molecules. In Sun-Earth-like UV radiation environments, H (and in some cases O) will rapidly destroy nearly all biosignature gases of interest. The lower UV fluxes from UV-quiet M stars would produce a lower concentration of H (or O) for the same scenario, enabling some biosignature gases to accumulate. The favorability of low-UV radiation environments to accumulate detectable biosignature gases in an H 2 atmosphere is closely analogous to the case of oxidized atmospheres, where photochemically produced OH is the major destructive species. Most potential biosignature gases, such as dimethylsulfide and CH 3 Cl, are therefore more favorable in low-UV, as compared with solar-like UV, environments. A few promising biosignature gas candidates, including NH 3 and N 2 O, are favorable even in solar-like UV environments, as these gases are destroyed directly by photolysis and not by H (or O). A more subtle finding is that most gases produced by life that are fully hydrogenated forms of an element, such as CH 4 and H 2 S, are not effective signs of life in an H 2 -rich atmosphere because the dominant atmospheric chemistry will generate such gases abiologically, through photochemistry or geochemistry. Suitable biosignature gases in H 2 -rich atmospheres for super-Earth exoplanets transiting M stars could potentially be detected in transmission spectra with the James Webb Space Telescope

  11. Chemistry of Planetary Atmospheres: Insights and Prospects

    Science.gov (United States)

    Yung, Yuk

    2015-11-01

    Using observations from the Mariners, Pioneers, Vikings, Voyagers, Pioneer Venus, Galileo, Venus Express, Curiosity, Cassini, New Horizons, and numerous observatories both in orbit of Earth and on the ground, I will give a survey of the major chemical processes that control the composition of planetary atmospheres. For the first time since the beginning of the space age, we understand the chemistry of planetary atmospheres ranging from the primitive atmospheres of the giant planets to the highly evolved atmospheres of terrestrial planets and small bodies. Our understanding can be distilled into three important ideas: (1) The stability of planetary atmospheres against escape of their constituents to space, (2) the role of equilibrium chemistry in determining the partitioning of chemical species, and (3) the role of disequilibrium chemistry, which produces drastic departures from equilibrium chemistry. To these three ideas we must also add a fourth: the role of biochemistry at Earth's surface, which makes its atmospheric chemistry unique in the cosmochemical environment. Only in the Earth's atmosphere do strong reducing and oxidizing species coexist to such a degree. For example, nitrogen species in the Earth's atmosphere span eight oxidation states from ammonia to nitric acid. Much of the Earth's atmospheric chemistry consists of reactions initiated by the degradation of biologically produced molecules. Life uses solar energy to drive chemical reactions that would otherwise not occur; it represents a kind of photochemistry that is special to Earth, at least within the Solar System. It remains to be seen how many worlds like Earth there are beyond the Solar System, especially as we are now exploring the exoplanets using Kepler, TESS, HST, Spitzer, soon to be launched missions such as JWST and WFIRST, and ground-based telescopes. The atmospheres of the Solar System provide a benchmark for studying exoplanets, which in turn serve to test and extend our current

  12. Characterizing stellar and exoplanetary environments

    CERN Document Server

    Khodachenko, Maxim

    2015-01-01

    In this book an international group of specialists discusses studies of exoplanets subjected to extreme stellar radiation and plasma conditions. It is shown that such studies will help us to understand how terrestrial planets and their atmospheres, including the early Venus, Earth and Mars, evolved during the host star’s active early phase. The book presents an analysis of findings from Hubble Space Telescope observations of transiting exoplanets, as well as applications of advanced numerical models for characterizing the upper atmosphere structure and stellar environments of exoplanets. The authors also address detections of atoms and molecules in the atmosphere of “hot Jupiters” by NASA’s Spitzer telescope. The observational and theoretical investigations and discoveries presented are both timely and important in the context of the next generation of space telescopes. 
 The book is divided into four main parts, grouping chapters on exoplanet host star radiation and plasma environments, exoplanet u...

  13. Atmospheric pollution in Lisbon urban atmosphere

    Science.gov (United States)

    Oliveira, C.

    2009-04-01

    Lisbon is the capital city of Portugal with about 565,000 residents in 2008 and a population density of 6,600 inhabitants per square kilometre. Like several other major metropolis, the town is surrounded by satellite cities, forming together a region known as "Lisbon Metropolitan Area" with about 3 million inhabitants, a quarter of the overall Portuguese population. Besides their local residents, it is estimated that more than one million citizens come into the Lisbon area every day from the outskirts, leading to elevated traffic densities and intense traffic jams, with important consequences on air pollution levels and obvious negative impacts on human health. Airborne particulate matter limit values are frequently exceeded, making urgent the existence of consistent programs to monitor and help taking measures to control them. Within the Portuguese project PAHLIS (Polycyclic Aromatic Hydrocarbons Contamination in Lisbon Urban Atmosphere) financed by the Portuguese Science Foundation ("Fundação para a Ciência e a Tecnologia"), an aerosol and vapour phase sampling program is being implemented in the city of Lisbon at two selected contrasting zones, namely a typically busy area with intense road traffic and frequent exceedences of the particulate matter standard for the maximum allowable concentration, and a residential quieter area, thus with a cleaner atmosphere characterised as an urban background site. An one month-long sampling campaign was performed during the summer of 2008, where particulate matter was collected in two fractions (coarse 2.5µmmethod was applied on a portion of the aerosol collected on the quartz filters to quantify black or elemental and organic carbon (EC/OC). Another portion of the quartz filters was Soxhlet extracted with dichloromethane and the resulting extracts fractionated by flash chromatography prior to gas chromatography-mass spectrometry (GC-MS) analysis regarding their organic content. The inorganic content of particulate

  14. Variation of atmospheric tritium concentrations in Fukuoka, Japan

    International Nuclear Information System (INIS)

    Okai, T.; Momoshima, N.

    2005-01-01

    Tritium is present in the atmosphere in various chemical forms, such as tritiated water vapor (HTO), tritiated hydrogen (HT) and tritiated methane (CH 3 T). Atmospheric tritium levels had remarkably increased because of atmospheric nuclear tests in the 1950's and the early 1960's, and they have been decreasing as a radioactive decay and removal process from a atmosphere. It is important to know the present background levels in each chemical form of tritium in the atmosphere for analysis of the tritium behavior in the environment or for assessment of the public dose. Therefore, tritium concentrations of atmospheric HTO, HT and CH 3 T have been measured in Fukuoka, Japan from 1984 to the present. The present HTO concentrations are already close to the tritium level before nuclear tests. However, the present HT and CH 3 T concentrations are still higher by a factor of 74 and 22, respectively, than those before the tests. (author)

  15. Atmospheric pollution; Pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lambrozo, J.; Guillossou, G. [EDF-Gas de France, Service des Etudes Medicales, 75 - Paris (France)

    2008-10-15

    The atmosphere is the reservoir of numerous pollutants (nitrogen oxides, sulfur oxides, carbon oxides, particulates, volatile organic compounds, polycyclic aromatic hydrocarbons) from natural origin or anthropogenic origin ( industry, transport, agriculture, district heating). With epidemiologic studies the atmospheric pollution is associated with an increase of respiratory and cardiovascular diseases. At the european level, the technological progress, the legislation have allowed a reduction of pollutant emissions, however these efforts have to be continued because the sanitary impact of atmospheric pollution must not be underestimated, even if the risks appear less important that these ones in relation with tobacco, inside pollution or others factors of cardiovascular risks. Indeed, on these last factors an individual action is possible for the exposure to air pollution people have no control. (N.C.)

  16. Atmosphere and Ambient Space

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Atmosphere and Ambient Space This paper explores the relation between atmosphere and ambient space. Atmosphere and ambient space share many salient properties. They are both ontologically indeterminate, constantly varying and formally diffuse and they are both experienced as a subtle, non......-signifying property of a given space. But from a certain point of view, the two concepts also designate quite dissimilar experiences of space. To be ’ambient’ means to surround. Accordingly, ambient space is that space, which surrounds something or somebody. (Gibson 1987: 65) Since space is essentially...... of a surrounding character, all space can thus be described as having a fundamentally ambient character. So what precisely is an ambient space, then? As I will argue in my presentation, ambient space is a sensory effect of spatiality when a space is experienced as being particularly surrounding: a ‘space effect...

  17. Phenomenology of atmospheric neutrinos

    Directory of Open Access Journals (Sweden)

    Fedynitch Anatoli

    2016-01-01

    Full Text Available The detection of astrophysical neutrinos, certainly a break-through result, introduced new experimental challenges and fundamental questions about acceleration mechanisms of cosmic rays. On one hand IceCube succeeded in finding an unambiguous proof for the existence of a diffuse astrophysical neutrino flux, on the other hand the precise determination of its spectral index and normalization requires a better knowledge about the atmospheric background at hundreds of TeV and PeV energies. Atmospheric neutrinos in this energy range originate mostly from decays of heavy-flavor mesons, which production in the phase space relevant for prompt leptons is uncertain. Current accelerator-based experiments are limited by detector acceptance and not so much by the collision energy. This paper recaps phenomenological aspects of atmospheric leptons and calculation methods, linking recent progress in flux predictions with particle physics at colliders, in particular the Large Hadron Collider.

  18. Photochemistry of Pluto's Atmosphere

    Science.gov (United States)

    Krasnopolsky, Vladimir A.

    1999-01-01

    This work include studies of two problems: (1) Modeling thermal balance, structure. and escape processes in Pluto's upper atmosphere. This study has been completed in full. A new method, of analytic solution for the equation of hydrodynamic flow from in atmosphere been developed. It was found that the ultraviolet absorption by methane which was previously ignored is even more important in Pluto's thermal balance than the extreme ultraviolet absorption by nitrogen. Two basic models of the lower atmosphere have been suggested, with a tropopause and a planetary surface at the bottom of the stellar occultation lightcurve, respectively, Vertical profiles, of temperature, density, gas velocity, and the CH4 mixing ratio have been calculated for these two models at low, mean, and high solar activity (six models). We prove that Pluto' " s atmosphere is restricted to 3060-4500 km, which makes possible a close flyby of future spacecraft. Implication for Pluto's evolution have also been discussed. and (2) Modeling of Pluto's photochemistry. Based on the results of (1), we have made some changes in the basic continuity equation and in the boundary conditions which reflect a unique can of hydrodynamic escape and therefore have not been used in modeling of other planetary atmospheres. We model photochemistry of 44 neutral and 23 ion species. This work required solution of a set of 67 second-order nonlinear ordinary differential equations. Two models have been developed. Each model consists of the vertical profiles for 67 species, their escape and precipitation rates. These models predict the chemical structure and basic chemical processes in the current atmosphere and possible implication of these processes for evolution. This study has also been completed in full.

  19. Photosynthesis in hydrogen-dominated atmospheres.

    Science.gov (United States)

    Bains, William; Seager, Sara; Zsom, Andras

    2014-11-18

    The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life.

  20. Photosynthesis in Hydrogen-Dominated Atmospheres

    Directory of Open Access Journals (Sweden)

    William Bains

    2014-11-01

    Full Text Available The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life.

  1. Photosynthesis in Hydrogen-Dominated Atmospheres

    Science.gov (United States)

    Bains, William; Seager, Sara; Zsom, Andras

    2014-01-01

    The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H2-dominated atmosphere. If a rocky, H2-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH4-based photosynthesis as compared with CO2-based photosynthesis. We find that a by-product biosignature gas is likely to be H2, which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life. PMID:25411926

  2. Parameters of atmospheric radioactivity in Bulgaria

    International Nuclear Information System (INIS)

    Yaneva, B.; Todorov, P.; Georgieva, D.

    2006-01-01

    Bulgaria is a country which is located on the Balkan Peninsula, at the Eastern part of Europe. There are a lot of polluting sources, which can affect the environmental parameters and human health. One of these parameters is a radioactivity. It can be as a result from natural and anthropological sources. One of the most important sources of radiological influence to the environment and its components is from atmosphere. Anthropological sources of atmospheric pollution are Nuclear power plants, different kinds of industrial plants, and so on. The systematic control on these parameters is made by the Ministry of environment and water in Bulgaria. The atmospheric radioactivity research is based on collecting of many samples and its examine. The collecting of these aerosol samples on different kind of filters is automatic and it is put into practice by fixed stations located in some of the main towns in Bulgaria - Sofia, Varna, Burgas, Vratza and Montana. The required amount of air for each sample is 1000m 3 . These samples are analyzed by gamma-spectrometry analysis for determination of specifies activity of natural and anthropological radionuclides in them. Monitoring data for the atmospheric radioactivity can be characterized by concentrations of Cs-137, Be-7. The results show that concentrations of Cs-137 are 3 and the concentrations for Be-7 vary from 0.7 to 15.7 mBq/m 3 . Other important radionuclides are Sr-90, Uranium and Ra-226

  3. Atmospheric transport of radionuclides

    International Nuclear Information System (INIS)

    Crawford, T.V.

    1978-01-01

    The chairman and contributors are members of the Working Group on Atmospheric Dispersion, Deposition, and Resuspension. This group examined the mathematical approaches for determining the direct and indirect pathways to man of releases of pollutants to the atmosphere. The dose-to-man limitations promulgated by the Nuclear Regulatory Commission, the Environmental Protection Agency, and the Energy Research and Development Administration were presented. The present status of research was discussed, and recommendations for future work were made. Particular emphasis was placed on the need for additional experimental work to develop confidence limits leading to acceptable probability statements of critical pathways for determining the dose-to-man

  4. Atmospheric Absorption Cell Characterization.

    Science.gov (United States)

    1982-06-01

    was adequate for making empty cell measurements and filling the cell with artificial atmospheres. The procedure used in pumping and fillin the cell...carbon dioxide, nitrogen, and nitrous oxide. The artificial atmospheres in the cell used for these measurements are summarized in Table IV. Figures...LD_l -_10J J« LUZ . jr-U «—• »r—• «-CD CO — Q- —a CD -j" \\z — OC I — h- \\_IC\\J CM LUD -ÜU T 1 r 00*001 00󈧌 00*09 00*0

  5. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... other information showing complete procedural details of the test atmosphere generation, verification...

  6. The use of atmospheric dispersion models in risk assessment decision support systems for pesticides

    NARCIS (Netherlands)

    Leeuw, de F.A.A.M.; Pul, van W.A.J.; Berg, van den F.; Gilbert, A.J.

    2000-01-01

    In the evaluation of potentially adverse effects of organic chemicals such as pesticides on the environment the atmosphere may play an important role. After its release to the atmosphere the chemical will be transported/dispersed in the atmosphere andfinally it will be removed either by

  7. Ubiquity of bisphenol A in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Fu Pingqing, E-mail: pqfu@pop.lowtem.hokudai.ac.j [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Kawamura, Kimitaka, E-mail: kawamura@lowtem.hokudai.ac.j [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan)

    2010-10-15

    Bisphenol A (BPA) is a suspected endocrine disruptor in the environment. However, little is known about its distribution and transport in the atmosphere. Here, the concentrations of BPA in the atmospheric aerosols from urban, rural, marine, and the polar regions were measured using solvent extraction/derivatization and gas chromatography/mass spectrometry technique. The concentrations of BPA (1-17,400 pg m{sup -3}) ranged over 4 orders of magnitude in the world with a declining trend from the continent (except for the Antarctica) to remote sites. A positive correlation was found between BPA and 1,3,5-triphenylbenzene, a tracer for plastic burning, in urban regions, indicating that the open burning of plastics in domestic waste should be a significant emission source of atmospheric BPA. Our results suggest that the ubiquity of BPA in the atmosphere may raise a requirement for the evaluation of health effects of BPA in order to control its emission sources, for example, from plastic burning. - This study gives first insight into the sources and global distributions of bisphenol A (BPA) in the atmosphere.

  8. Geologic emissions of methane to the atmosphere.

    Science.gov (United States)

    Etiope, Giuseppe; Klusman, Ronald W

    2002-12-01

    The atmospheric methane budget is commonly defined assuming that major sources derive from the biosphere (wetlands, rice paddies, animals, termites) and that fossil, radiocarbon-free CH4 emission is due to and mediated by anthropogenic activity (natural gas production and distribution, and coal mining). However, the amount of radiocarbon-free CH4 in the atmosphere, estimated at approximately 20% of atmospheric CH4, is higher than the estimates from statistical data of CH4 emission from fossil fuel related anthropogenic sources. This work documents that significant amounts of "old" methane, produced within the Earth crust, can be released naturally into the atmosphere through gas permeable faults and fractured rocks. Major geologic emissions of methane are related to hydrocarbon production in sedimentary basins (biogenic and thermogenic methane) and, subordinately, to inorganic reactions (Fischer-Tropsch type) in geothermal systems. Geologic CH4 emissions include diffuse fluxes over wide areas, or microseepage, on the order of 10(0)-10(2) mg m(-2) day(-1), and localised flows and gas vents, on the order of 10(2) t y(-1), both on land and on the seafloor. Mud volcanoes producing flows of up to 10(3) t y(-1) represent the largest visible expression of geologic methane emission. Several studies have indicated that methanotrophic consumption in soil may be insufficient to consume all leaking geologic CH4 and positive fluxes into the atmosphere can take place in dry or seasonally cold environments. Unsaturated soils have generally been considered a major sink for atmospheric methane, and never a continuous, intermittent, or localised source to the atmosphere. Although geologic CH4 sources need to be quantified more accurately, a preliminary global estimate indicates that there are likely more than enough sources to provide the amount of methane required to account for the suspected missing source of fossil CH4.

  9. Atmospheric Models for Engineering Applications

    Science.gov (United States)

    Johnson, Dale L.; Roberts, Barry C.; Vaughan, William W.; Justus, C. G.

    2002-01-01

    This paper will review the historical development of reference and standard atmosphere models and their applications. The evolution of the U.S. Standard Atmosphere will be addressed, along with the Range Reference Atmospheres and, in particular, the NASA Global Reference Atmospheric Model (GRAM). The extensive scope and content of the GRAM will be addressed since it represents the most extensive and complete 'Reference' atmosphere model in use today. Its origin was for engineering applications and that remains today as its principal use.

  10. Atmosphere beyond Poetics

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2014-01-01

    Physical Presence in Space.” Oase #91, Building Atmosphere, 21-33 Sloterdijk, Peter. (2005) 2008. “The Crystal Palace.” Translated by Michael Darroch. Public 37: Public?, 12-15. Originally published in Peter Sloterdijk. Im Weltinnenraum des Kapitals: Für eine philoso-phische Theorie der Globalisierung, 265...

  11. Astronomy and Atmospheric Optics

    Science.gov (United States)

    Cowley, Les; Gaina, Alex

    2011-12-01

    The authors discusse the insuccess of the observation of the Total Eclipse of the Moon from 10 december 2011 in Romania and relate them with meteoconditions. Only a very short part of the last penumbral phase was observed, while the inital part and the totality was not observed due to very dense clouds. The change in color and brightness during this phase was signaled. Meanwhile, there is an area of science where clouds are of great use and interest. This area is Atmospheric optics, while the science which study clouds is meteorology. Clouds in combination with Solar and Moon light could give rise to a variety of strange, rare and unobvious phenomena in the atmosphere (sky), sometimes confused with Unidentified Flying Objects (UFO). The importance of meteorology for astronomy and atmospheric optics is underlined and an invitation to astronomers to use unfavourable days for athmospheric observations was sent. The web address of the site by Les Cowley, designed for atmospheric optics phenomena is contained in the text of the entry.

  12. Results from atmospheric neutrinos

    Indian Academy of Sciences (India)

    Abstract. With the announcement of new evidence for muon neutrino disappearance observed by the super-Kamiokande experiment, the more than a decade old atmospheric neutrino anomaly moved from a possible indication for neutrino oscillations to an apparently inescapable fact. The evidence is reviewed, and new ...

  13. Atmospheric Heavy Metal Pollution

    Indian Academy of Sciences (India)

    within and below cloud scavenging, whereby the wet aerosol particles are collected by falling raindrops. In occult deposition, wetted particles (fog and mist) are deposited by impaction or turbulent transfer [3]. A high proportion of atmospheric heavy metals entering aquatic systems is in small particulate « IJlm) or soluble ...

  14. Atmospheric Heavy Metal Pollution

    Indian Academy of Sciences (India)

    elements which constitute an important class of pollutants. Such ... Hence, the transfer of air borne particles to land or water surfaces ... relative importance of these processes depends primarily on the size of the particles. Anthropogenically added particulates and aerosols in atmosphere show a broad size distribution from.

  15. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  16. Atmospheric and aerosol chemistry

    International Nuclear Information System (INIS)

    McNeill, V. Faye; Ariya, Parisa A.; McGill Univ. Montreal, QC

    2014-01-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  17. Atmospheric and laser propagation

    NARCIS (Netherlands)

    Eijk, A.M.J. van; Stein, K.

    2017-01-01

    This paper reviews three phenomena that affect the propagation of electro-optical radiation through the atmosphere: absorption and scattering, refraction and turbulence. The net effect on imaging or laser systems is a net reduction of the effective range, or a degradation of the information

  18. Climate and atmospheric research

    International Nuclear Information System (INIS)

    Kramer, G.; Schumacher, R.

    1992-01-01

    This issue of the scientific journal of the Humboldt university is dedicated to results of research work carried out to the greatest extent at the meteorological institute in the last two years on the area of climate and atmospheric research. The traditional research areas of the institute are climatology and the dynamics of the atmosphere, in particular the atmospherical boundary layer. Considering the high probability of a global climatic fluctuation due to the anthropogenic change of composition of the atmosphere and other climate-relevant factors imminent in the next century, climatological research today is an important part of global and regional environmental research. From the necessity of determination and evaluation of the effect of climatic fluctuations on nature and society the contours of a new interdisciplinary research area are already visible now. This is suitable as hardly any other area to be the supporting idea of environmental research at universities. The contributions contained in the issue already consider, in addition to results on climate diagnosis, also results on aspects of climate effect research. (orig./KW) [de

  19. Atmospheric and aerosol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, V. Faye [Columbia Univ., New York, NY (United States). Dept. of Chemical Engineering; Ariya, Parisa A. (ed.) [McGill Univ. Montreal, QC (Canada). Dept. of Chemistry; McGill Univ. Montreal, QC (Canada). Dept. of Atmospheric and Oceanic Sciences

    2014-09-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  20. Atmosphere as colloid

    International Nuclear Information System (INIS)

    Kutsenogij, K.P.; Kutsenogij, P.K.

    2008-01-01

    In the paper review the results of experimental and theoretical investigations on space-time variability of physical, chemical and biological atmospheric characteristics and its influence on climate, ecology and environmental quality under the impact of natural processes and anthropogenic load is submitted

  1. Results from atmospheric neutrinos

    Indian Academy of Sciences (India)

    With the announcement of new evidence for muon neutrino disappearance observed by the super-Kamiokande experiment, the more than a decade old atmospheric neutrino anomaly moved from a possible indication for neutrino oscillations to an apparently inescapable fact. The evidence is reviewed, and new indications ...

  2. Atoms and atmosphere

    International Nuclear Information System (INIS)

    Megie, G.

    1994-01-01

    The ozone sources, roles and distribution are reviewed, and the atmosphere dynamic effects on ozone circulation are discussed; chlorine and CFC are the two main perturbative agents of the ozone layer and their effects are described and analyzed; impacts of the limitation of the CFC and chlorine utilization are discussed. 5 figs., 9 tabs

  3. ESA Atmospheric Toolbox

    Science.gov (United States)

    Niemeijer, Sander

    2017-04-01

    The ESA Atmospheric Toolbox (BEAT) is one of the ESA Sentinel Toolboxes. It consists of a set of software components to read, analyze, and visualize a wide range of atmospheric data products. In addition to the upcoming Sentinel-5P mission it supports a wide range of other atmospheric data products, including those of previous ESA missions, ESA Third Party missions, Copernicus Atmosphere Monitoring Service (CAMS), ground based data, etc. The toolbox consists of three main components that are called CODA, HARP and VISAN. CODA provides interfaces for direct reading of data from earth observation data files. These interfaces consist of command line applications, libraries, direct interfaces to scientific applications (IDL and MATLAB), and direct interfaces to programming languages (C, Fortran, Python, and Java). CODA provides a single interface to access data in a wide variety of data formats, including ASCII, binary, XML, netCDF, HDF4, HDF5, CDF, GRIB, RINEX, and SP3. HARP is a toolkit for reading, processing and inter-comparing satellite remote sensing data, model data, in-situ data, and ground based remote sensing data. The main goal of HARP is to assist in the inter-comparison of datasets. By appropriately chaining calls to HARP command line tools one can pre-process datasets such that two datasets that need to be compared end up having the same temporal/spatial grid, same data format/structure, and same physical unit. The toolkit comes with its own data format conventions, the HARP format, which is based on netcdf/HDF. Ingestion routines (based on CODA) allow conversion from a wide variety of atmospheric data products to this common format. In addition, the toolbox provides a wide range of operations to perform conversions on the data such as unit conversions, quantity conversions (e.g. number density to volume mixing ratios), regridding, vertical smoothing using averaging kernels, collocation of two datasets, etc. VISAN is a cross-platform visualization and

  4. Atmospheric Dispersion from Elevated Sources in an Urban Area: Comparison between Tracer Experiments and Model Calculations

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Lyck, Erik

    1984-01-01

    Results from tracer experiments carried out to study the ability of the atmosphere to disperse nonbuoyant effluents released from an elevated point source in an urban environment are described.......Results from tracer experiments carried out to study the ability of the atmosphere to disperse nonbuoyant effluents released from an elevated point source in an urban environment are described....

  5. Encapsulated environment

    NARCIS (Netherlands)

    McLellan, Tom M.; Daanen, Hein A M; Cheung, Stephen S.

    2013-01-01

    In many occupational settings, clothing must be worn to protect individuals from hazards in their work environment. However, personal protective clothing (PPC) restricts heat exchange with the environment due to high thermal resistance and low water vapor permeability. As a consequence, individuals

  6. Iowa's Environment.

    Science.gov (United States)

    Ruth, Amy, Ed.

    1994-01-01

    This theme issue explores the changes in Iowa's environment. When Native Americans lived in Iowa hundreds of years ago, the land was rich in tall grasslands, fertile soil, wildlife, wetlands, and unpolluted waters. When European-American pioneers settled Iowa in 1833, they changed the environment in order to survive. The first article in this…

  7. The airport atmospheric environment: respiratory health at work.

    Science.gov (United States)

    Touri, Léa; Marchetti, Hélène; Sari-Minodier, Irène; Molinari, Nicolas; Chanez, Pascal

    2013-06-01

    Air traffic is increasing, raising concern about local pollution and its adverse health effects on the people living in the vicinity of large airports. However, the highest risk is probably occupational exposure due to proximity. Jet exhaust is one of the main concerns at an airport and may have a health impact, particularly on the respiratory tract. Current studies are neither numerous enough nor strong enough to prove this kind of association. Yet, more and more people work in airports, and occupational exposure to jet exhaust is a fact. The aim of this review was to evaluate the existing knowledge regarding the impact of airport pollution on respiratory health. We conducted systematic literature searches to examine workplace exposures.

  8. The Changing Atmosphere: UNEP Environment Brief No. 1.

    Science.gov (United States)

    United Nations Environment Programme, Nairobi (Kenya).

    Discussed are the following topics: (1) the greenhouse problem, including the processes involved and some possible resulting scenarios; (2) ozone, the "umbrella" protecting the earth from lethal concentrations of ultraviolet rays and the problem of decreasing ozone levels; (3) what could happen as the earth gets warmer (including…

  9. 46 CFR 151.03-19 - Environment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Environment. 151.03-19 Section 151.03-19 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Definitions § 151.03-19 Environment. This term refers to the atmosphere...

  10. Global atmospheric moisture variability

    Science.gov (United States)

    Robertson, Franklin R.; James, Bonnie F.; Chi, Kay; Huang, Huo-Jin

    1989-01-01

    Research efforts during FY-88 have focused on completion of several projects relating to analysis of FGGE data during SOP-1 and on expanded studies of global atmospheric moisture. In particular, a revised paper on the relationship between diabatic heating and baroclinicity in the South Pacific Convergence Zone (SPCZ) was submitted. A summary of completed studies on diagnostic convective parameterization was presented at the Satellite Meteorology and Oceanography Convergence last February. These investigations of diabatic heating in the SPCZ have demonstrated the requirement for a more quantitative description of atmospheric moisture. As a result, efforts were directed toward use of passive remote microwave measurements from the Nimbus-7 SMMR and the DOD's Special Sensor Microwave Imager (SSMI/I) as critical sources of moisture data. Activities this year are summarized.

  11. Venus Middle Atmosphere Chemistry

    Science.gov (United States)

    Mills, F. P.; Sundaram, M.; Slanger, T. G.; Allen, M.; Yung, Y. L.

    2005-08-01

    Venus is the most similar planet to Earth, and years of research have sought to understand their similarities and differences. Yet, it is still not clear what chemical processes maintain the long-term stability of Venus' primarily CO2 atmosphere. CO2 dissociates into CO and O after absorbing photons at wavelengths Express will be reviewed. Recent work evaluating newly proposed mechanisms for producing CO2, which could be important depending on the rates of poorly constrained reactions, will be described. This research was supported by funding from NASA's Planetary Atmospheres program and the Australian Research Council. Part of this work was carried out by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. [1] Nair, et al., Icarus 111, 124 (1994), [2] Trauger and Lunine, Icarus 55, 272 (1983), [3] Pernice, et al., PNAS 101, 14007 (2004)

  12. Atmospheric lepton fluxes

    Directory of Open Access Journals (Sweden)

    Gaisser Thomas K.

    2015-01-01

    Full Text Available This review of atmospheric muons and neutrinos emphasizes the high energy range relevant for backgrounds to high-energy neutrinos of astrophysical origin. After a brief historical introduction, the main distinguishing features of atmospheric νμ and νe are discussed, along with the implications of the muon charge ratio for the νµ / ν̅µ ratio. Methods to account for effects of the knee in the primary cosmic-ray spectrum and the energy-dependence of hadronic interactions on the neutrino fluxes are discussed and illustrated in the context of recent results from IceCube. A simple numerical/analytic method is proposed for systematic investigation of uncertainties in neutrino fluxes arising from uncertainties in the primary cosmic-ray spectrum/composition and hadronic interactions.

  13. Contaminants in the Atmosphere

    DEFF Research Database (Denmark)

    Skov, H.; Bossi, R.; Wåhlin, P.

    This report presents the results of atmospheric monitoring in Nuuk, Greenland. A long series of heavy metals and persistent organic Pollutants (POPs) have been measured and model calculations have been carried out supporting the interpretation of the results. Financially, the Danish Environmental...... Protection Agency supported this work with means from the MIKA/DANCEA funds for Environmental Support to the Arctic Region and the work is part of the Danish contribution to Arctic Monitoring and Assessment Programme, AMAP...

  14. Atmospheric tides on Neptune

    International Nuclear Information System (INIS)

    Dement'ev, M.S.; Morozhenko, A.V.

    1989-01-01

    The dependence of the equivalent width of the methane absorption band at 619 nm in the Neptune's spectrum upon the Triton's orbital position is discovered. It is assumed that observed changes of the equivalent width of the band and colour index (J - K) (Belton et al., 1981; Brown et al., 1981; Cruikshank, 1978) are due to atmospheric tides (period 2 d .9375) and Neptune's rotation (period 10 h .14)

  15. Mining the Mars Atmosphere

    Science.gov (United States)

    Finn, John E.; Sridhar, K. R.

    1997-01-01

    A series of concepts have been developed to mine the atmosphere of Mars and process it to extract or generate compressed carbon dioxide, compressed buffer gas mixtures of nitrogen and argon, water, oxygen, carbon monoxide, and/or carbon. Such products can be of use to science instruments, robotic, and human missions. The products can be for utility purposes, life support, propulsion (both interplanetary and on the planet's surface), and power generation.

  16. 40 CFR 1065.190 - PM-stabilization and weighing environments for gravimetric analysis.

    Science.gov (United States)

    2010-07-01

    ... weighing environments free of ambient contaminants, such as dust, aerosols, or semi-volatile material that... not been within the applicable tolerances for the past 60 min. (2) Continuously measure atmospheric... atmospheric pressure outside the weighing environment, as long as you can ensure that atmospheric pressure at...

  17. DREAMING OF ATMOSPHERES

    Energy Technology Data Exchange (ETDEWEB)

    Waldmann, I. P., E-mail: ingo@star.ucl.ac.uk [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT (United Kingdom)

    2016-04-01

    Here, we introduce the RobERt (Robotic Exoplanet Recognition) algorithm for the classification of exoplanetary emission spectra. Spectral retrieval of exoplanetary atmospheres frequently requires the preselection of molecular/atomic opacities to be defined by the user. In the era of open-source, automated, and self-sufficient retrieval algorithms, manual input should be avoided. User dependent input could, in worst-case scenarios, lead to incomplete models and biases in the retrieval. The RobERt algorithm is based on deep-belief neural (DBN) networks trained to accurately recognize molecular signatures for a wide range of planets, atmospheric thermal profiles, and compositions. Reconstructions of the learned features, also referred to as the “dreams” of the network, indicate good convergence and an accurate representation of molecular features in the DBN. Using these deep neural networks, we work toward retrieval algorithms that themselves understand the nature of the observed spectra, are able to learn from current and past data, and make sensible qualitative preselections of atmospheric opacities to be used for the quantitative stage of the retrieval process.

  18. DREAMING OF ATMOSPHERES

    International Nuclear Information System (INIS)

    Waldmann, I. P.

    2016-01-01

    Here, we introduce the RobERt (Robotic Exoplanet Recognition) algorithm for the classification of exoplanetary emission spectra. Spectral retrieval of exoplanetary atmospheres frequently requires the preselection of molecular/atomic opacities to be defined by the user. In the era of open-source, automated, and self-sufficient retrieval algorithms, manual input should be avoided. User dependent input could, in worst-case scenarios, lead to incomplete models and biases in the retrieval. The RobERt algorithm is based on deep-belief neural (DBN) networks trained to accurately recognize molecular signatures for a wide range of planets, atmospheric thermal profiles, and compositions. Reconstructions of the learned features, also referred to as the “dreams” of the network, indicate good convergence and an accurate representation of molecular features in the DBN. Using these deep neural networks, we work toward retrieval algorithms that themselves understand the nature of the observed spectra, are able to learn from current and past data, and make sensible qualitative preselections of atmospheric opacities to be used for the quantitative stage of the retrieval process

  19. Model atmospheres for Betelgeuse.

    Science.gov (United States)

    Fay, T. D.; Johnson, H. R.

    1973-01-01

    Detailed comparison of a series of stellar atmospheric models at effective temperatures of 3800 and 3500 K with scanner observations of Betelgeuse (alpha Ori, M2 Iab). The atmospheres are hydrostatic, flux-constant, LTE atmospheres which include the opacity of H2O, CO, CN, and atomic line blanketing. To reduce the flux shortward of 6000 A enough to agree with observations requires either strong atomic line blanketing (or a similar opacity source) or significant reddening, or (likely) both. The visual extinction (an estimate of which depends strongly on the line blanketing, especially in the 1- to 2-micron region) lies between 0.4 and 2.0 mag. Comparison of predicted strengths of observed CO and CN features with observations and of predicted column densities of CO, OH, NH, and H2O with published column densities suggests that C/H may be less than its solar value by about a factor of 10 and C/O may be less than 0.6 in Betelgeuse.

  20. Atmospheric radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P. [Universidade Federal do ABC (UFABC), SP (Brazil); Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10{sup 17} eV and 10{sup 18} eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < {lambda} < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  1. Atmospheric radiation monitor

    International Nuclear Information System (INIS)

    Oliveira, M.A. Leigui de; Peixoto, C.J. Todero; Leao, M.S.A.B.; Luzio, V.P.; Barbosa, A.F.; Lima Junior, H.P.; Vilar, A.B.; Gama, R.G.; Ferraz, V.A.

    2011-01-01

    Full text: The Atmospheric Radiation Monitor (MonRAt) is a compact telescope designed to detect fluorescence photons generated in the atmosphere by ultra-high energy cosmic rays showers with energies in the interval between 10 17 eV and 10 18 eV. It is composite by a 64 pixels MultiAnodic PhotoMultiplier Tube (MAPMT) placed at the focus of a parabolic mirror mounted in a Newtonian telescope setup and the data acquisition system. In front of the MAPMT photocathode, filters will be positioned to select light with wavelength in the near ultraviolet region (300 nm < λ < 450 nm) where the nitrogen fluorescent emissions occurs. The data acquisition system consists of a set of pre-amplifiers and FPGA-based boards able to record trigger times and waveforms from each channel and send the data to a computer by USB ports. MonRAt will be used to detect fluorescence photons under different atmospheric conditions (pressure, temperature, humidity, local geomagnetic field, etc) and will contribute with a detailed study of the fluorescence radiation yield. The assembly of the telescope is under way and we present in this work the status of the experiment and its first measurements in the laboratory. (author)

  2. Dreaming of Atmospheres

    Science.gov (United States)

    Waldmann, I. P.

    2016-04-01

    Here, we introduce the RobERt (Robotic Exoplanet Recognition) algorithm for the classification of exoplanetary emission spectra. Spectral retrieval of exoplanetary atmospheres frequently requires the preselection of molecular/atomic opacities to be defined by the user. In the era of open-source, automated, and self-sufficient retrieval algorithms, manual input should be avoided. User dependent input could, in worst-case scenarios, lead to incomplete models and biases in the retrieval. The RobERt algorithm is based on deep-belief neural (DBN) networks trained to accurately recognize molecular signatures for a wide range of planets, atmospheric thermal profiles, and compositions. Reconstructions of the learned features, also referred to as the “dreams” of the network, indicate good convergence and an accurate representation of molecular features in the DBN. Using these deep neural networks, we work toward retrieval algorithms that themselves understand the nature of the observed spectra, are able to learn from current and past data, and make sensible qualitative preselections of atmospheric opacities to be used for the quantitative stage of the retrieval process.

  3. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  4. Robotic environments

    NARCIS (Netherlands)

    Bier, H.H.

    2011-01-01

    Technological and conceptual advances in fields such as artificial intelligence, robotics, and material science have enabled robotic architectural environments to be implemented and tested in the last decade in virtual and physical prototypes. These prototypes are incorporating sensing-actuating

  5. The nitrogen cycle: Atmosphere interactions

    Science.gov (United States)

    Levine, J. S.

    1984-01-01

    Atmospheric interactions involving the nitrogen species are varied and complex. These interactions include photochemical reactions, initiated by the absorption of solar photons and chemical kinetic reactions, which involve both homogeneous (gas-to-gas reactions) and heterogeneous (gas-to-particle) reactions. Another important atmospheric interaction is the production of nitrogen oxides by atmospheric lightning. The nitrogen cycle strongly couples the biosphere and atmosphere. Many nitrogen species are produced by biogenic processes. Once in the atmosphere nitrogen oxides are photochemically and chemically transformed to nitrates, which are returned to the biosphere via precipitation, dry deposition and aerosols to close the biosphere-atmosphere nitrogen cycle. The sources, sinks and photochemistry/chemistry of the nitrogen species; atmospheric nitrogen species; souces and sinks of nitrous oxide; sources; sinks and photochemistry/chemistry of ammonia; seasonal variation of the vertical distribution of ammonia in the troposphere; surface and atmospheric sources of the nitrogen species, and seasonal variation of ground level ammonia are summarized.

  6. Healthy Environments

    OpenAIRE

    2012-01-01

    This issue of Early Childhood in Focus draws attention to some key global challenges in providing healthy environments for young children. Section 1 recognises that multisectoral policy responses are needed to ensure adequate housing and improved water and sanitation, as well as recreational spaces. For young children, physical spaces are closely intertwined with emotional security and feelings of well-being. Section 2 explores the opportunities and challenges of living in urban environments....

  7. Atmospheric Climate Experiment Plus

    Science.gov (United States)

    Lundahl, K.

    ACE+ is an atmospheric sounding mission using radio occultation techniques and is a combination of the two Earth Explorer missions ACE and WATS earlier proposed to ESA. ACE was highly rated by ESA in the Call for Earth Explorer Opportunity Missions in 1999 and was prioritised as number three and selected as a "hot-stand-by". A phase A study was carried out during 2000 and 2001. ACE will observe atmospheric parameters using radio occultations from an array of 6 micro-satellites which track the L- band signal of GPS satellites to map the detailed refractivity and thermal structure of the global atmosphere from surface to space. Water vapour and wind in Atmospheric Troposphere and Stratosphere WATS was the response to ESA's Call for Ideas for the next Earth Explorer Core Missions in 2001. WATS combines ACE GPS atmospheric occultations and LEO-LEO cross-link occultations. Cross-links strongly enhance the capability of measuring humidity relative to the ACE mission. The Earth Science Advisory Committée at ESA noted that the LEO-GNSS occultation technique is already well established through several missions in recent years and could not recommend WATS for a Phase A study as an Earth Explorer Core Mission. The ESAC was, however, deeply impressed by the LEO-LEO component of the WATS proposal and would regard it as regrettable if this science would be lost and encourages the ACE/WATS team to explore other means to achieve its scientific goal. ACE+ is therefore the response to ESA's 2nd Call for Earth Explorer Opportunity Missions in 2001 and will contribute in a significant manner to ESA's Living Planet Programme. ACE+ will considerably advance our knowledge about atmosphere physics and climate change processes. The mission will demonstrate a highly innovative approach using radio occultations for globally measuring profiles of humidity and temperature throughout the atmosphere and stratosphere. A constellation of 4 small satellites, tracking L-band GPS/GALILEO signals and

  8. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; Díaz, I.; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  9. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, Manuel; Fuente, Daniel de la; Díaz, Iván; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morpholog...

  10. Atmospheric corrosion of mild steel. Pt. II. Marine atmospheres

    International Nuclear Information System (INIS)

    Almeida, E.; Morcillo, M.; Rosales, B.

    2000-01-01

    This paper summarizes the results obtained in the MICAT project for mild steel specimens exposed for 1 to 4 years in 47 marine atmospheres in the Ibero-American region. All these atmospheres were characterized for climatology, pollution and corrosion rates according to ISO standards. Complementary morphological and chemical characterization of the steel corrosion product layers (SCPLs) formed in these atmospheres was carried out. The overall analysis of results contributes to understanding, in a systematic way, how atmospheric corrosivity categories can be correlated with corrosion mechanisms. Special aspects of the atmospheres, from pure to mixed marine, were considered. (orig.)

  11. Heat transfer in the atmosphere

    NARCIS (Netherlands)

    Oerlemans, J.

    1982-01-01

    The atmosphere is almost transparent to solar radiation and almost opaque to terrestrial radiation. This implies that in the mean the atmosphere cools while the earth's surface is heated. Convection in the lower atmosphere must therefore occur. The upward flux of energy associated with it

  12. Middle atmosphere dynamics and composition

    International Nuclear Information System (INIS)

    Geller, M.A.

    1981-01-01

    In this paper we have adopted the term middle atmosphere to describe that region of the earth's atmosphere that lies above the tropopause but below an altitude of 100 km. In the following then, we will briefly touch on a few aspects of middle atmosphere dynamics and composition concentrating on only those topics that are important at middle and high latitudes. (orig./WL)

  13. Evaluation of satellites and remote sensors for atmospheric pollution measurements

    Science.gov (United States)

    Carmichael, J.; Eldridge, R.; Friedman, E.; Keitz, E.

    1976-01-01

    An approach to the development of a prioritized list of scientific goals in atmospheric research is provided. The results of the analysis are used to estimate the contribution of various spacecraft/remote sensor combinations for each of several important constituents of the stratosphere. The evaluation of the combinations includes both single-instrument and multiple-instrument payloads. Attention was turned to the physical and chemical features of the atmosphere as well as the performance capability of a number of atmospheric remote sensors. In addition, various orbit considerations were reviewed along with detailed information on stratospheric aerosols and the impact of spacecraft environment on the operation of the sensors.

  14. Atmosphere: A Source of Pathogenic or Beneficial Microbes?

    Directory of Open Access Journals (Sweden)

    Paraskevi N. Polymenakou

    2012-01-01

    Full Text Available The atmosphere has been described as one of the last frontiers of biological exploration on Earth. The composition of microbial communities in the atmosphere is still not well-defined, and taxonomic studies of bacterial diversity in the outdoor air have just started to emerge, whereas our knowledge about the functional potential of air microbiota is scant. When in the air, microorganisms can be attached to ambient particles and/or incorporated into water droplets of clouds, fog, and precipitation (i.e., rain, snow, hail. Further, they can be deposited back to earth’s surfaces via dry and wet deposition processes and they can possibly induce an effect on the diversity and function of aquatic and terrestrial ecosystems or impose impacts to human health through microbial pathogens dispersion. In addition to their impact on ecosystem and public health, there are strong indications that air microbes are metabolically active and well adapted to the harsh atmospheric conditions. Furthermore they can affect atmospheric chemistry and physics, with important implications in meteorology and global climate. This review summarizes current knowledge about the ubiquitous presence of microbes in the atmosphere and discusses their ability to survive in the atmospheric environment. The purpose is to evaluate the atmospheric environment as a source of pathogenic or beneficial microbes and to assess the biotechnological opportunities that may offer.

  15. On the Atmospheric Correction of Antarctic Airborne Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Martin Black

    2014-05-01

    Full Text Available The first airborne hyperspectral campaign in the Antarctic Peninsula region was carried out by the British Antarctic Survey and partners in February 2011. This paper presents an insight into the applicability of currently available radiative transfer modelling and atmospheric correction techniques for processing airborne hyperspectral data in this unique coastal Antarctic environment. Results from the Atmospheric and Topographic Correction version 4 (ATCOR-4 package reveal absolute reflectance values somewhat in line with laboratory measured spectra, with Root Mean Square Error (RMSE values of 5% in the visible near infrared (0.4–1 µm and 8% in the shortwave infrared (1–2.5 µm. Residual noise remains present due to the absorption by atmospheric gases and aerosols, but certain parts of the spectrum match laboratory measured features very well. This study demonstrates that commercially available packages for carrying out atmospheric correction are capable of correcting airborne hyperspectral data in the challenging environment present in Antarctica. However, it is anticipated that future results from atmospheric correction could be improved by measuring in situ atmospheric data to generate atmospheric profiles and aerosol models, or with the use of multiple ground targets for calibration and validation.

  16. Synthetic environments

    Science.gov (United States)

    Lukes, George E.; Cain, Joel M.

    1996-02-01

    The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

  17. Effect of controlled adverse chamber environment exposure on tear functions in silicon hydrogel and hydrogel soft contact lens wearers.

    Science.gov (United States)

    Kojima, Takashi; Matsumoto, Yukihiro; Ibrahim, Osama M A; Wakamatsu, Tais Hitomi; Uchino, Miki; Fukagawa, Kazumi; Ogawa, Junko; Dogru, Murat; Negishi, Kazuno; Tsubota, Kazuo

    2011-11-11

    To prospectively evaluate the effect of controlled adverse chamber environment (CACE) exposure on tear function, including tear osmolarity, in subjects wearing narafilcon A versus those wearing etafilcon A soft contact lens (SCL). Thirty-one healthy subjects with no history of contact lens wear (13 women, 18 men; average age, 30.5 ± 6.5 years) were randomly divided into age- and sex-matched groups (15 subjects wearing narafilcon A SCL; 16 subjects wearing etafilcon A SCL) and entered a CACE for 20 minutes. All subjects underwent tear osmolarity, tear evaporation rate, strip meniscometry, tear film breakup time, fluorescein vital staining, and functional visual acuity measurement before and after exposure to the controlled adverse chamber. The mean blink rate increased with significant deteriorations in the mean symptom VAS scores, mean tear osmolarity, tear evaporation rate, strip meniscometry score, and tear stability with CACE exposure along with a decrease in visual maintenance ratio in functional visual acuity testing in etafilcon A wearers. The mean symptom VAS scores, mean tear evaporation rate, tear stability, blink rates, and visual maintenance ratios did not change significantly in narafilcon A wearers after CACE exposure. This study suggested marked tear instability, higher tear osmolarity, and increased tear evaporation with marked dry eye and visual symptomatology in nonadapted hydrogel SCL wearers, suggesting that silicone hydrogel SCLs may be suitable for persons who live and work in cool, low-humidity, and windy environments, as tested in this study.

  18. MOBILE ATMOSPHERIC SENSING

    Directory of Open Access Journals (Sweden)

    L. Wang

    2017-11-01

    Full Text Available Atmospheric quality dramatically deteriorates over the past decades around themetropolitan areas of China. Due to the coal combustion, industrial air pollution, vehicle waste emission, etc., the public health suffers from exposure to such air pollution as fine particles of particulates, sulfur and carbon dioxide, etc. Many meteorological stations have been built to monitor the condition of air quality over the city. However, they are installed at fixed sites and cover quite a small region. The monitoring results of these stations usually do NOT coincide with the public perception of the air quality. This paper is motivated to mimic the human breathing along the citys transportation network by the mobile sensing vehicle of atmospheric quality. To obtain the quantitative perception of air quality, the Environmental Monitoring Vehicle of Wuhan University (EMV-WHU has been developed to automatically collect the data of air pollutants. The EMV-WHU is equipped with GPS/IMU, sensors of PM2.5, carbon dioxide, anemometer, temperature, humidity, noise, and illumination, as well as the visual and infrared camera. All the devices and sensors are well collaborated with the customized synchronization mechanism. Each sort of atmospheric data is accompanied with the uniform spatial and temporal label of high precision. Different spatial and data-mining techniques, such as spatial correlation analysis, logistic regression, spatial clustering, are employed to provide the periodic report of the roadside air quality. With the EMV-WHU, constant collection of the atmospheric data along the Luoyu Road of Wuhan city has been conducted at the daily peak and non-peak time for half a year. Experimental results demonstrated that the EMV is very efficient and accurate for the perception of air quality. Comparative findings with the meteorological stations also show the intelligence of big data analysis and mining of all sorts of EMV measurement of air quality. It is

  19. Atmospheres of central stars

    International Nuclear Information System (INIS)

    Hummer, D.G.

    1978-01-01

    The author presents a brief summary of atmospheric models that are of possible relevance to the central stars of planetary nebulae, and then discusses the extent to which these models accord with the observations of both nebulae and central stars. Particular attention is given to the significance of the very high Zanstra temperature implied by the nebulae He II lambda 4686 A line, and to the discrepancy between the Zanstra He II temperature and the considerably lower temperatures suggested by the appearance of the visual spectrum for some of these objects. (Auth.)

  20. Habituating alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie

    This paper proposes embodied rhythmic sound habituation as a possible resource when designing contextualized technologies in critical atmospheres. The main contribution is collating the concept of rhythm as presented by Henri Lefebvre with the concept of sound habituation to help operationalize...... accustomed to the alarming sounds through rhythmic interaction in the waiting room, and bringing the furniture with them afterwards as a secure anchor, when entering the ward. This rhythmic habituation can enable the child to focus her attention on the meeting with the hospitalized relative....

  1. Enacting Environments

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2013-01-01

    Enacting Environments is an ethnography of the midst of the encounter between corporations, sustainable development and climate change. At this intersection 'environmental management' and 'carbon accounting' are put into practice. Purportedly, these practices green capitalism. Drawing on fieldwork...... of day-to-day practices of corporate environmental accountants and managers, Ingmar Lippert reconstructs their work as achieving to produce a reality of environment that is simultaneously stable and flexible enough for a particular corporate project: to stage the company, and in consequence capitalism......, as in control over its relations to an antecedent environment. Not confined to mere texts or meetings between shiny stakeholders co-governing the corporation – among them some of the world's biggest auditing firms, an environmental non-governmental organisation (NGO) and standards – control is found...

  2. Atmospheric corrosion of mild steel in Oman

    International Nuclear Information System (INIS)

    Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.

    2006-01-01

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  3. An EUV spectrometer for atmospheric remote sensing

    International Nuclear Information System (INIS)

    Chakrabarti, S.; Cotton, D.M.; Lampton, M.; Siegmund, O.H.W.; Link, R.

    1989-01-01

    This paper describes the Berkeley EUV Airglow Rocket Spectrometer (BEARS) experiment, designed to investigate the interactions between the solar ionizing radiation and the earth's upper atmosphere. The primary objective of this experiment is the verification the feasibility of using EUV observations as a quantitative diagnostic of the terrestrial atmosphere and its plasma environment. The expected information provided by spectroscopic measurements of EUV emission will include data on the excitation mechanisms, excitation rates, and branching ratios. The BEARS experimental package consists of a high-resolution EUV airglow spectrometer, a hydrogen Lyman-alpha photometer to measure both the solar radiations and the geocoronal emissions, and a moderate-resolution solar EUV spectrometer. In a test experiment, the instruments were carried aboard a four-stage sounding rocket to a peak altitude of about 960 km and obtained airglow spectra in the 980-1060 A range and in the 1300-1360 range. 34 refs

  4. 5th International Conference on Atmospheric Electricity

    CERN Document Server

    Reiter, Reinhold; Landsberg, Helmut

    1976-01-01

    These Proceedings are published to give a full account of the Fifth International Conference on Atmospheric Electricity held in September 1974 in Garmisch-Partenkirchen in the Bavarian Alps in Germany. Traditionally, the Proceedings of these Conferences have served as reference books updating the textbooks and monographs on Atmospheric Electricity. As treated by these Conferences, Atmos­ pheric Electricity covers all aspects of this science, including the processes and problems which reach out into the Earth's environment as well as analogous processes on other planets and on the Moon. A history of these Conferences, an account of their purpose, and an outline of the scope and the preparation is to be found at the end of these Proceedings. There, also the Business Meetings of the involved organizations are mentioned. The Proceedings closely follow the original program and are accordingly organized into "Sessions". The papers printed in each "Session" in this book are the ones which were accepted for the sess...

  5. Atmospheric corrosion of mild steel in Oman

    Energy Technology Data Exchange (ETDEWEB)

    Gismelseed, Abbasher, E-mail: abbasher@squ.edu.om; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K. [College of Science, Department of Physics (Oman)

    2006-01-15

    A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.

  6. Atmospheric mercury footprints of nations.

    Science.gov (United States)

    Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

    2015-03-17

    The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

  7. Preliminary Analysis of Pyrite Reactivity Under Venusian Temperature and Atmosphere

    Science.gov (United States)

    Radoman-Shaw, B. G.; Harvey, R. P.; Jacobson, N. S.; Costa, G. C. C.

    2015-01-01

    Measurements of Venus surface chemistry suggest a basaltic composition with a predominantly CO2 atmosphere. In order to understand the reactivity of certain possible mineral species on the surface, previous simulation chambers conduct experiments at 1 atmosphere with a simplified CO2 atmosphere. Following this procedure, pyrite (FeS2) samples are used to estimate the reactivity of sulfide minerals under a Venusian atmosphere and climate. Sulfurous gas species have been identified and quantified in the Venusian atmosphere, and sulfurous gas and mineral species are known to be created through volcanism, which is suggested to still occur on the surface of Venus. This experimentation is necessary to constrain reactions that could occur between the surface and atmosphere of Venus to understand terrestrial geology in a thick and hot greenhouse atmosphere. Quantifying this reaction can lead to approximations necessary for further experimentation in more complex environments such as those in the GEER chamber at Glenn Research Center that can simulate pressure along with temperature and a more inclusive and representative Venusian atmosphere.

  8. Developing Tighter Constraints on Exoplanet Biosignatures by Modeling Atmospheric Haze

    Science.gov (United States)

    Felton, Ryan; Neveu, Marc; Domagal-Goldman, Shawn David; Desch, Steven; Arney, Giada

    2018-01-01

    As we increase our capacity to resolve the atmospheric composition of exoplanets, we must continue to refine our ability to distinguish true biosignatures from false positives in order to ultimately distinguish a life-bearing from a lifeless planet. Of the possible true and false biosignatures, methane (CH4) and carbon dioxide (CO2) are of interest, because on Earth geological and biological processes can produce them on large scales. To identify a biotic, Earth-like exoplanet, we must understand how these biosignatures shape their atmospheres. High atmospheric abundances of CH4 produce photochemical organic haze, which dramatically alters the photochemistry, climate, and spectrum of a planet. Arney et al. (2017) have suggested that haze-bearing atmospheres rich in CO2 may be a type of biosignature because the CH4 flux required to produce the haze is similar to the amount of biogenic CH4 on modern Earth. Atmospheric CH4 and CO2 both affect haze-formation photochemistry, and the potential for hazes to form in Earth-like atmospheres at abiotic concentrations of these gases has not been well studied. We will explore a wide range of parameter space of abiotic concentration levels of these gases to determine what spectral signatures are possible from abiotic environments and look for measurable differences between abiotic and biotic atmospheres. We use a 1D photochemical model with an upgraded haze production mechanism to compare Archean and modern Earth atmospheres to abiotic versions while varying atmospheric CH4 and CO2 levels and atmospheric pressure. We will vary CO2 from a trace gas to an amount such that it dominates atmospheric chemistry. For CH4, there is uncertainty regarding the amount of abiotic CH4 that comes from serpentinizing systems. To address this uncertainty, we will model three cases: 1) assume all CH4 comes from photochemistry; 2) use estimates of modern-day serpentinizing fluxes, assuming they are purely abiotic; and 3) assume serpentinizing

  9. Species Egalitarianism and the Environment

    Directory of Open Access Journals (Sweden)

    Kristin Tiili

    2014-06-01

    Full Text Available A general anthropocentric view of the human species affects the environment and is a major contributing factor in the environmental crisis we are currently facing. A species egalitarian society would have positive effects on the crisis, and particularly in regards to short term goals of decreasing greenhouse gases in the atmosphere. Additionally it would increase the quality of life and alleviate the suffering of countless beings, nonhuman animals and humans alike.

  10. Observing environments

    DEFF Research Database (Denmark)

    Alrøe, Hugo Fjelsted; Noe, Egon

    2012-01-01

    in different ways. The aim of this paper is to clarify the conceptions of environment in constructivist approaches, and thereby to assist the sciences of complex systems and complex environmental problems. Method: We describe the terms used for “the environment” in von Uexküll, Maturana & Varela, and Luhmann...

  11. African Environment

    African Journals Online (AJOL)

    Environmental Studies and Regional Planning Bulletin African Environment is published in French and English, and for some issues, in Arabic. (only the issue below has been received by AJOL). Vol 10, No 3 (1999). DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Table of ...

  12. Architecture & Environment

    Science.gov (United States)

    Erickson, Mary; Delahunt, Michael

    2010-01-01

    Most art teachers would agree that architecture is an important form of visual art, but they do not always include it in their curriculums. In this article, the authors share core ideas from "Architecture and Environment," a teaching resource that they developed out of a long-term interest in teaching architecture and their fascination with the…

  13. Greenhouse effect in the atmosphere

    Science.gov (United States)

    Smirnov, B. M.

    2016-04-01

    Average optical atmospheric parameters for the infrared spectrum range are evaluated on the basis of the Earth energetic balance and parameters of the standard atmosphere. The average optical thickness of the atmosphere is u ≈ 2.5 and this atmospheric emission is originated at altitudes below 10 km. Variations of atmospheric radiative fluxes towards the Earth and outward are calculated as a function of the concentration of \\text{CO}2 molecules for the regular model of molecular spectrum. As a result of doubling of the \\text{CO}2 concentration the change of the global Earth temperature is (0.4 +/- 0.2) \\text{K} if other atmospheric parameters are conserved compared to the value (3.0 +/- 1.5) \\text{K} under real atmospheric conditions with the variation of the amount of atmospheric water. An observed variation of the global Earth temperature during the last century (0.8 ^\\circ \\text{C}) follows from an increase of the mass of atmospheric water by 7% or by conversion of 1% of atmospheric water in aerosols.

  14. Caustics of atmospheric waves

    Science.gov (United States)

    Godin, Oleg A.

    2015-04-01

    Much like light and sound, acoustic-gravity waves in inhomogeneous atmosphere often have a caustic or caustics, where the ray theory predicts unphysical, divergent values of the wave amplitude and needs to be modified. Increase of the wave magnitude in the vicinity of a caustic makes such vicinities of primary interest in a number of problems, where a signal needs to be separated from a background noise. The value of wave focusing near caustics should be carefully quantified in order to evaluate possible nonlinearities promoted by the focusing. Physical understanding of the wave field in the vicinity of a caustic is also important for understanding of the wave reflection from and transmission (tunneling) through the caustic. To our knowledge, in contrast to caustics of acoustic, electromagnetic, and seismic waves as well as gravity waves in incompressible fluids, asymptotics of acoustic-gravity waves in the vicinity of a caustic have never been studied systematically. In this paper, we fill this gap. Atmospheric waves are considered as linear acoustic-gravity waves in a neutral, horizontally stratified, moving ideal gas of variable composition. Air temperature and wind velocity are assumed to be gradually varying functions of height, and slowness of these variations determines the large parameter of the problem. The scale height of the atmosphere can be large or small compared to the vertical wavelength. It is found that the uniform asymptotics of the wave field in the presence of a simple caustic can be expressed in terms of the Airy function and its derivative. As for the acoustic waves, the argument of the Airy function is expressed in terms of the eikonal calculated in the ray, or WKB, approximation. The geometrical, or Berry, phase, which arises in the consistent WKB approximation for acoustic-gravity waves, plays an important role in the caustic asymptotics. In the uniform asymptotics, the terms with the Airy function and its derivative are weighted by cosine

  15. Role of natural radiation environment in earth sciences

    International Nuclear Information System (INIS)

    Vohra, K.G.

    1980-01-01

    Natural ionizing radiations play an important role in a wide spectrum of earth sciences, including meteorology, geophysics, hydrology, atmospheric physics, and atmospheric chemistry. The nature and distribution of ionizing radiation sources and natural radionuclides in the atmospheric environment are summarized. The present status of the use of natural radioactive tracers for atmospheric studies is discussed. The effect of ionization produced by natural radiation sources on atmospheric electricity, the relationship of electrical and meteorological variables, and the possible effects of man-made releases of 85 Kr are considered. Experimental evidence is presented for the production of condensation nuclei by the combined effects of radon and sulfur dioxide

  16. Radioiodine in the environment

    International Nuclear Information System (INIS)

    Grauby, A.; Saas, A.

    1979-01-01

    An experimental procedure was developed in order to follow the pathways of radioiodine, 129 I especially, through the various compartments of nuclear plant environment: atmosphere, soil, plants, precipitations, ... A partial evaluation of the results is made. Data are supplied on iodine transfer into soil, iodine distribution one year later, release of iodine at the level of soil and plants. The intake of various forms of iodine in a soil and the evaluation of availability to plants by chemical tests showed that radioactive iodine ( 125 I) reached equilibrium with stable iodine after 120 - 140 days of incubation. During this time, there was a large amount of iodine exchangeable against a KI solution N/10. Equilibrium was reached progressively by iodine transfer on soil organic molecules. According to the origin of contamination, the transfer was more or less fast and differences were especially noticed in volatile iodine release and on chemical mobility. During intake, potential hazard of soil, groundwater, plant and atmospheric contaminations was greater. Iodine-129 is presently one of the chief contributors to air pollution around nuclear installations because of its radioactive half-life (1.72 x 10 7 yr) rather than on account of the amounts released. Just as with iodine-131, it is released into the atmosphere under many chemical forms. However, 129 I reaches man through several food chains and not only through the air-grass-cow-milk food chain. The values of its deposition rate on soil and plants are fairly dispersed because of its changing reactivity due to its chemical instability. On account of this chemical complexity, the transfer of iodine along the air-soil-plant system was studied using 125 I. (author)

  17. 13. Atmosphere and climate

    International Nuclear Information System (INIS)

    Mock, G.; Hammond, A.

    1992-01-01

    This chapter reports on past and current trends in the major forms of atmospheric pollution and on the relative contributions of the countries of the world to these emissions. It also reports on emissions of carbon dioxide from industrial processes - principally the combustion of fossil fuels - which is the largest single source of greenhouse gases and an appropriate target for initial efforts to limit emissions. Discussions are presented on the following: urban air pollution - sources, trends and effects (particulates, sulfur dioxide, smog and its precursors, indoor air pollution, carbon monoxide, lead); regional air pollution - sources, trends and effects (acid deposition, ground-level ozone, regional responses and emission trends, acceleration of ozone depletion); solutions (cleaning up stationary sources, corporate responsibility movement, reducing vehicle pollution); global climate treaty talks proceed; greenhouse gas emissions; and targets for limiting emissions

  18. Phytoremediation of Atmospheric Methane

    Science.gov (United States)

    2013-04-15

    greenhouse gases produced by human activity are  carbon   dioxide , methane and  nitrous oxide.  Much attention has been directed toward CO2 mitigation...surface  ocean .   Acidification  and ultimately warming due to CO2 alone must be  addressed by removing CO2 from the atmosphere and prevention of further...as a  carbon  and energy source. One soluble MMO (sMMO)  system is expressed by some methanotrophs under conditions of low copper concentration and

  19. Atmospheric propagation of THz radiation.

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael Clement; Mangan, Michael A.; Foltynowicz, Robert J.

    2005-11-01

    In this investigation, we conduct a literature study of the best experimental and theoretical data available for thin and thick atmospheres on THz radiation propagation from 0.1 to 10 THz. We determined that for thick atmospheres no data exists beyond 450 GHz. For thin atmospheres data exists from 0.35 to 1.2 THz. We were successful in using FASE code with the HITRAN database to simulate the THz transmission spectrum for Mauna Kea from 0.1 to 2 THz. Lastly, we successfully measured the THz transmission spectra of laboratory atmospheres at relative humidities of 18 and 27%. In general, we found that an increase in the water content of the atmosphere led to a decrease in the THz transmission. We identified two potential windows in an Albuquerque atmosphere for THz propagation which were the regions from 1.2 to 1.4 THz and 1.4 to 1.6 THz.

  20. Atmospheric turbulence and diffusion research

    International Nuclear Information System (INIS)

    Hosker, R.P. Jr.

    1993-01-01

    The Atmospheric Turbulence and Diffusion Division (well known in the atmospheric dispersion community as the Atmospheric Turbulence and Diffusion Laboratory, ATDL) is one of several field facilities of NOAAs Air Resources Laboratory, headquartered in Silver Spring, Maryland. The laboratory conducts research on matters of atmospheric diffusion and turbulent exchange, concerning air quality. ATDD focuses attention on the physics of the lower atmosphere, with special emphasis on the processes contributing to atmospheric transport, dispersion, deposition, and air-surface exchange, and on the development of predictive capabilities using the results of this research. Research is directed toward issues of national and global importance related to the missions of DOE, to DOE's Oak Ridge Field Office, and to NOAA. The program is divided into four major projects: plume transport and diffusion in the planetary boundary layer, complex topography, canopy micrometeorology, and air-surface exchange

  1. Measurements of atmospheric electricity aloft

    OpenAIRE

    Nicoll, K.A.

    2012-01-01

    Measurements of the electrical characteristics of the atmosphere above the surface have been made for over 200 years, from a variety of different platforms, including kites, balloons, rockets and aircraft. From these measurements, a great deal of information about the electrical characteristics of the atmosphere has been gained, assisting our understanding of the global atmospheric electric circuit, thunderstorm electrification and lightning generation mechanisms, discovery of transient lumin...

  2. Stochastic background of atmospheric cascades

    International Nuclear Information System (INIS)

    Wilk, G.; Wlodarczyk, Z.

    1993-01-01

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions

  3. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

    2011-01-01

    Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

  4. Influence of Dust Loading on Atmospheric Ionizing Radiation on Mars

    Science.gov (United States)

    Norman, Ryan B.; Gronoff, Guillaume; Mertens, Christopher J.

    2014-01-01

    Measuring the radiation environment at the surface of Mars is the primary goal of the Radiation Assessment Detector on the NASA Mars Science Laboratory's Curiosity rover. One of the conditions that Curiosity will likely encounter is a dust storm. The objective of this paper is to compute the cosmic ray ionization in different conditions, including dust storms, as these various conditions are likely to be encountered by Curiosity at some point. In the present work, the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model, recently modified for Mars, was used along with the Badhwar & O'Neill 2010 galactic cosmic ray model. In addition to galactic cosmic rays, five different solar energetic particle event spectra were considered. For all input radiation environments, radiation dose throughout the atmosphere and at the surface was investigated as a function of atmospheric dust loading. It is demonstrated that for galactic cosmic rays, the ionization depends strongly on the atmosphere profile. Moreover, it is shown that solar energetic particle events strongly increase the ionization throughout the atmosphere, including ground level, and can account for the radio blackout conditions observed by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on the Mars Express spacecraft. These results demonstrate that the cosmic rays' influence on the Martian surface chemistry is strongly dependent on solar and atmospheric conditions that should be taken into account for future studies.

  5. Plants in alpine environments

    Science.gov (United States)

    Germino, Matthew J.

    2014-01-01

    Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations. Low atmospheric pressure is the most pervasive, fundamental, and unifying factor for alpine environments, but the resulting decrease in partial pressure of CO2 does not significantly limit carbon gain by alpine plants. Factors such as tree islands and topographic features create strong heterogeneous mosaics of microclimate and snow cover that are reflected in plant community composition. Factors affecting tree establishment and growth and formation of treeline are key to understanding alpine ecology. Carbohydrate and other carbon storage, rapid development in a short growing season, and physiological function at low temperature are prevailing attributes of alpine plants. A major contemporary research theme asks whether chilling at alpine-treeline affects the ability of trees to assimilate the growth resources and particularly carbon needed for growth or whether the growth itself is limited by the alpine environment. Alpine areas tend to be among the best conserved, globally, yet they are increasingly showing response to a range of anthropogenic impacts, such as atmospheric deposition.

  6. Dynamic simulation for distortion image with turbulence atmospheric transmission effects

    Science.gov (United States)

    Du, Huijie; Fei, Jindong; Qing, Duzheng; Zhao, Hongming; Yu, Hong; Cheng, Chen

    2013-09-01

    The imaging through atmospheric turbulence is an inevitable problem encountered by infrared imaging sensors working in the turbulence atmospheric environment. Before light-rays enter the window of the imaging sensors, the atmospheric turbulence will randomly interfere with the transmission of the light waves came from the objects, causing the distribution of image intensity values on the focal plane to diffuse, the peak value to decrease, the image to get blurred, and the pixels to deviate, and making image identification very difficult. Owing to the fact of the long processing time and that the atmospheric turbulent flow field is unknown and hard to be described by mathematical models, dynamic simulation for distortion Image with turbulence atmospheric transmission effects is much more difficult and challenging in the world. This paper discusses the dynamic simulation for distortion Image of turbulence atmospheric transmission effect. First of all, with the data and the optical transmission model of the turbulence atmospheric, the ray-tracing method is applied to obtain the propagation path of optical ray which propagates through the high-speed turbulent flow field, and then to calculate the OPD from the reference wave to the reconverted wave front and obtain the point spread function (PSF). Secondly, infrared characteristics models of typical scene were established according to the theory of infrared physics and heat conduction, and then the dynamic infrared image was generated by OpenGL. The last step is to obtain the distortion Image with turbulence atmospheric transmission effects .With the data of atmospheric transmission computation, infrared simulation image of every frame was processed according to the theory of image processing and the real-time image simulation, and then the dynamic distortion simulation images with effects of blurring, jitter and shifting were obtained. Above-mentioned simulation method can provide the theoretical bases for recovering

  7. The nuclear energy for the environment protection

    International Nuclear Information System (INIS)

    Souza, Jair A.M. de.

    1992-01-01

    The environmental question is currently the greater preoccupation all the world, particularly, the atmospheric pollution, generating the acid rains and the heater effect. The transportation, residential, agricultural, industrial and electric sectors contribute for the atmospheric pollution. In this work, the author analyzes important actions in Europe and United States of America in order to reduce this pollution. The paper intends to demystifies that the nuclear energy would be harmful to the environment, demonstrating exactly the contrary - due to the emission cares and controls coming from the nuclear power plants, this source of electric energy generation constitutes is an important factor of environment protection

  8. Environs monitoring

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    There were no releases of gaseous waste from ORNL which were of a level that required an incident report to the ERDA. The average concentration of beta radioactivity in the atmosphere at the perimeter of the ERDA-controlled area was less than one percent of the value appliable to releases to uncontrolled areas. There were no releases of liquid waste from the Laboratory which were of a level that required an incident report to the ERDA. The quantity of radionuclides of primary concern in the Clinch River averaged less than 0.4 percent of the MPC/sub w/. The average background level at the PAM and RAM stations during 1974 was 7.5 μR/hr, or 0.3 μR/hr less than the average for 1973. Nine soil samples were collected and analyzed for plutonium and uranium. Plutonium content ranged from 0.9 x 10 -8 μCi/g to 3.4 x 10 -8 μCi/g, and the uranium content ranged from 43 x 10 -8 /g to 117 x 10 -8 μCi/g. (auth)

  9. Box models for the evolution of atmospheric oxygen: an update.

    Science.gov (United States)

    Kasting, J F

    1991-01-01

    A simple 3-box model of the atmosphere/ocean system is used to describe the various stages in the evolution of atmospheric oxygen. In Stage I, which probably lasted until redbeds began to form about 2.0 Ga ago, the Earth's surface environment was generally devoid of free O2, except possibly in localized regions of high productivity in the surface ocean. In Stage II, which may have lasted for less than 150 Ma, the atmosphere and surface ocean were oxidizing, while the deep ocean remained anoxic. In Stage III, which commenced with the disappearance of banded iron formations around 1.85 Ga ago and has lasted until the present, all three surface reservoirs contained appreciable amounts of free O2. Recent and not-so-recent controversies regarding the abundance of oxygen in the Archean atmosphere are identified and discussed. The rate of O2 increase during the Middle and Late Proterozoic is identified as another outstanding question.

  10. Does toxicity of aromatic pollutants increase under remote atmospheric conditions?

    Science.gov (United States)

    Kroflič, Ana; Grilc, Miha; Grgić, Irena

    2015-03-09

    Aromatic compounds contribute significantly to the budget of atmospheric pollutants and represent considerable hazard to living organisms. However, they are only rarely included into atmospheric models which deviate substantially from field measurements. A powerful experimental-simulation tool for the assessment of the impact of low- and semi-volatile aromatic pollutants on the environment due to their atmospheric aqueous phase aging has been developed and introduced for the first time. The case study herein reveals that remote biotopes might be the most damaged by wet urban guaiacol-containing biomass burning aerosols. It is shown that only after the primary pollutant guaiacol has been consumed, its probably most toxic nitroaromatic product is largely formed. Revising the recent understanding of atmospheric aqueous phase chemistry, which is mostly concerned with the radical nitration mechanisms, the observed phenomenon is mainly attributed to the electrophilic nitrogen-containing reactive species. Here, their intriguing role is closely inspected and discussed from the ecological perspective.

  11. Molecular Dications in Planetary Atmospheric Escape

    Directory of Open Access Journals (Sweden)

    Stefano Falcinelli

    2016-08-01

    Full Text Available Fundamental properties of multiply charged molecular ions, such as energetics, structure, stability, lifetime and fragmentation dynamics, are relevant to understand and model the behavior of gaseous plasmas as well as ionosphere and astrophysical environments. Experimental determinations of the Kinetic Energy Released (KER for ions originating from dissociations reactions, induced by Coulomb explosion of doubly charged molecular ions (molecular dications produced by double photoionization of CO2, N2O and C2H2 molecules of interest in planetary atmospheres, are reported. The KER measurement as a function of the ultraviolet (UV photon energy in the range of 28–65 eV was extracted from the electron-ion-ion coincidence spectra obtained by using tunable synchrotron radiation coupled with ion imaging techniques at the ELETTRA Synchrotron Light Laboratory Trieste, Italy. These experiments, coupled with a computational analysis based on a Monte Carlo trajectory simulation, allow assessing the probability of escape for simple ionic species in the upper atmosphere of Mars, Venus and Titan. The measured KER in the case of H+, C+, CH+, CH2+, N+, O+, CO+, N2+ and NO+ fragment ions range between 1.0 and 5.5 eV, being large enough to allow these ionic species to participate in the atmospheric escape from such planets into space. In the case of Mars, we suggest a possible explanation for the observed behavior of the O+ and CO22+ ion density profiles.

  12. An application of gas chromatography to planetary atmospheres

    Science.gov (United States)

    Oyama, V.

    1974-01-01

    A gas chromatography developed for the Viking experiment is described. The instrument is designed to measure gases in planetary atmospheres and head space in a chamber. It is hoped that the chromatograph will also measure any biological activity present in these environments.

  13. An atmospheric electrical method to determine the eddy diffusion ...

    Indian Academy of Sciences (India)

    The ion–aerosol balance equations are solved to get the profiles of atmospheric electric parameters over the ground surface in an aerosol-rich environment under the conditions of surface radioactivity. Combining the earlier results for low aerosol concentrations and the present results for high aerosol concentrations ...

  14. Turbulence in Natural Environments

    Science.gov (United States)

    Banerjee, Tirtha

    Problems in the area of land/biosphere-atmosphere interaction, hydrology, climate modeling etc. can be systematically organized as a study of turbulent flow in presence of boundary conditions in an increasing order of complexity. The present work is an attempt to study a few subsets of this general problem of turbulence in natural environments- in the context of neutral and thermally stratified atmospheric surface layer, the presence of a heterogeneous vegetation canopy and the interaction between air flow and a static water body in presence of flexible protruding vegetation. The main issue addressed in the context of turbulence in the atmospheric surface layer is whether it is possible to describe the macro-states of turbulence such as mean velocity and turbulent velocity variance in terms of the micro-states of the turbulent flow, i.e., a distribution of turbulent kinetic energy across a multitude of scales. This has been achieved by a `spectral budget approach' which is extended for thermal stratification scenarios as well, in the process unifying the seemingly different and unrelated theories of turbulence such as Kolmogorov's hypothesis, Heisenberg's eddy viscosity, Monin Obukhov Similarity Theory (MOST) etc. under a common framework. In the case of a more complex scenario such as presence of a vegetation canopy with edges and gaps, the question that is addressed is in what detail the turbulence is needed to be resolved in order to capture the bulk flow features such as recirculation patterns. This issue is addressed by a simple numerical framework and it has been found out that an explicit prescription of turbulence is not necessary in presence of heterogeneities such as edges and gaps where the interplay between advection, pressure gradients and drag forces are sufficient to capture the first order dynamics. This result can be very important for eddy-covariance flux calibration strategies in non-ideal environments and the developed numerical model can be

  15. Sialyte(TM)-Based Composite Pressure Vessels for Extreme Environments, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — While traveling to Venus, electronics and instruments go through enormous pressure, temperature, and atmospheric environment changes. In the past, this has caused...

  16. NASA's Upper Atmosphere Research Program (UARP) and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1997-1999

    Science.gov (United States)

    Kurylo, M. J.; DeCola, P. L.; Kaye, J. A.

    2000-01-01

    Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology development, and monitoring of the Earth's upper atmosphere, with emphasis on the upper troposphere and stratosphere. This program aims at expanding our chemical and physical understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Research Division in the Office of Earth Science at NASA. Significant contributions to this effort have also been provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aero-Space Technology. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper troposphere and the stratosphere and their control on the distribution of atmospheric chemical species such as ozone; assess possible perturbations to the composition of the atmosphere caused by human activities and natural phenomena (with a specific emphasis on trace gas geographical distributions, sources, and sinks and the role of trace gases in defining the chemical composition of the upper atmosphere); understand the processes affecting the distributions of radiatively active species in the atmosphere, and the importance of chemical-radiative-dynamical feedbacks on the meteorology and climatology of the stratosphere and troposphere; and understand ozone production, loss, and recovery in an atmosphere with increasing abundances of greenhouse gases. The current report is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported

  17. Atmospheric Weathering of Historic Monuments and Their Related Conservation Issues

    Directory of Open Access Journals (Sweden)

    Caner-Saltık Emine N.

    2018-01-01

    Full Text Available Atmospheric environment affects the materials of historic monuments and their structure starting from the time of their construction. Daily and seasonal changes in temperature and humidity, wind, snow and rainfall, soluble salts carried by water, biological agents, pollutant gases and particulate matter are some of the agents in atmospheric environment that introduce weathering by physical, chemical and biological processes in the materials of the monuments such as natural building stones, bricks, mortars and plasters, mud brick etc. The weathering processes need to be well diagnosed by identification of main mechanisms of decay and major responsible agents, degree and depth of deterioration expressed with measurable parameters of physical, physicomechanical properties, and micro structural changes together with their distribution on the monument. Success of conservation treatments strongly depend on those diagnostic studies and compatibility of the treatments with the deteriorated and relatively sound parts of the historic materials. Current approach to materials conservation is to be able to make minimum intervention to historic material by targeting the conservation treatment to the deteriorated area for the purpose of controlling the deterioration factors and achieving compatible and durable conservation of historical material. In this presentation, two examples of diagnostic research and conservation treatments based on and guided by the diagnostic results are summarized concerning historic stone monuments exposed to atmospheric environment since more than two thousand years. The first example is on the marble walls of Temple of Augustus in Ankara exposed to polluted urban atmosphere. The second example is on the limestone statues of Nemrut Mount Monument in Adıyaman-Turkey, exposed to rural atmosphere with harsh climatic conditions. Finally, a brief discussion on current research issues related to historic materials conservation in

  18. The sources and fate of radionuclides emitted to the atmosphere

    International Nuclear Information System (INIS)

    Sandalls, J.

    2001-01-01

    The thesis represents an account of the sources and fate of radionuclides entering the atmosphere, and indicates where the candidate, through his own work, has contributed to the overall picture. The sources of the natural and man-made radionuclides found in the atmosphere are identified. New data on emissions from UK coal-fired power stations and UK steel works are reported. Radionuclides produced in nuclear fission and released to the atmosphere in the detonation of nuclear weapons, in nuclear accidents, and through routine discharges from nuclear sites have added to the atmospheric burden of radioactive materials; both acute and chronic low-level emissions are discussed. The various natural processes which remove radionuclides from the atmosphere are described. Soon after release, many radioactive materials become attached to the atmospheric aerosol, but others undergo gas-phase reactions. Some gases are sufficiently long-lived in the troposphere as to find their way into the stratosphere where their fate may be determined by the short-wave radiation from the sun. The nature of the particles of fuel emitted to the atmosphere in the explosion and fire at the Chernobyl nuclear power plant in 1986 are discussed, together with the associated environmental problems. The ground is the major sink for radionuclides leaving the atmosphere, and the behaviour of the more radiologically important radionuclides following deposition is described with special reference to: (i) fallout in both the urban and living environments; (ii) the pathways which may lead to contamination of the food chain; (iii) how the fuel particle fallout from Chernobyl was unique in nuclear accidents; (iv) soil-to-plant transfer of radioelements and (v) how radiation exposure of man can be mitigated in both the contaminated urban and rural environments. (author)

  19. Fetal environment

    International Nuclear Information System (INIS)

    Kinare, Arun

    2008-01-01

    The intrauterine environment has a strong influence on pregnancy outcome. The placenta and the umbilical cord together form the main supply line of the fetus. Amniotic fluid also serves important functions. These three main components decide whether there will be an uneventful pregnancy and the successful birth of a healthy baby. An insult to the intrauterine environment has an impact on the programming of the fetus, which can become evident in later life, mainly in the form of cardiovascular diseases, diabetes, and certain learning disabilities. The past two decades have witnessed major contributions from researchers in this field, who have included ultrasonologists, epidemiologists, neonatologists, and pediatricians. Besides being responsible for these delayed postnatal effects, abnormalities of the placenta, umbilical cord, and amniotic fluid also have associations with structural and chromosomal disorders. Population and race also influence pregnancy outcomes to some extent in certain situations. USG is the most sensitive imaging tool currently available for evaluation of these factors and can offer considerable information in this area. This article aims at reviewing the USG-related developments in this area and the anatomy, physiology, and various pathologies of the placenta, umbilical cord, and the amniotic fluid

  20. Criteria for controlled atmosphere chambers

    International Nuclear Information System (INIS)

    Robinson, J.N.

    1980-03-01

    The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

  1. Exploring the Atmosphere with Lidars

    Indian Academy of Sciences (India)

    sensing techniques provide powerful tools for scientific studies of the atmosphere .... (DIfferential Absorption Lidar) as powerful methods for many other measurements in the atmosphere. Table 1 summarizes .... f3 and a, lidar back scattered signals can be analysed to obtain altitude profiles of aerosol extinction coefficient.

  2. Organic chemistry in Titan's atmosphere

    Science.gov (United States)

    Scattergood, T.

    1982-01-01

    Laboratory photochemical simulations and other types of chemical simulations are discussed. The chemistry of methane, which is the major known constituent of Titan's atmosphere was examined with stress on what can be learned from photochemistry and particle irradiation. The composition of dust that comprises the haze layer was determined. Isotope fractionation in planetary atmospheres is also discussed.

  3. Remote measurement of atmospheric pollutants

    Science.gov (United States)

    Allario, F.; Hoell, J.; Seals, R. K.

    1979-01-01

    The concentration and vertical distribution of atmospheric ammonia and ozone are remotely sensed, using dual-C02-laser multichannel infrared Heterodyne Spectrometer (1HS). Innovation makes atmospheric pollution measurements possible with nearly-quantum-noise-limited sensitivity and ultrafine spectral resolution.

  4. Exploring the Atmosphere with Lidars

    Indian Academy of Sciences (India)

    Laser remote sensing of the atmosphere is generally referred as. LIDAR, the acronym for LIght Detection And Ranging. Simi- lar to radar, in lidar, a laser pulse is sent into the atmosphere and is used as a spectroscopic probe of its physical state and chemical composition. The emitted laser beam interacts with the atmo-.

  5. Linkages between terrestrial ecosystems and the atmosphere

    Science.gov (United States)

    Bretherton, Francis; Dickinson, Robert E.; Fung, Inez; Moore, Berrien, III; Prather, Michael; Running, Steven W.; Tiessen, Holm

    1992-01-01

    The primary research issue in understanding the role of terrestrial ecosystems in global change is analyzing the coupling between processes with vastly differing rates of change, from photosynthesis to community change. Representing this coupling in models is the central challenge to modeling the terrestrial biosphere as part of the earth system. Terrestrial ecosystems participate in climate and in the biogeochemical cycles on several temporal scales. Some of the carbon fixed by photosynthesis is incorporated into plant tissue and is delayed from returning to the atmosphere until it is oxidized by decomposition or fire. This slower (i.e., days to months) carbon loop through the terrestrial component of the carbon cycle, which is matched by cycles of nutrients required by plants and decomposers, affects the increasing trend in atmospheric CO2 concentration and imposes a seasonal cycle on that trend. Moreover, this cycle includes key controls over biogenic trace gas production. The structure of terrestrial ecosystems, which responds on even longer time scales (annual to century), is the integrated response to the biogeochemical and environmental constraints that develop over the intermediate time scale. The loop is closed back to the climate system since it is the structure of ecosystems, including species composition, that sets the terrestrial boundary condition in the climate system through modification of surface roughness, albedo, and, to a great extent, latent heat exchange. These separate temporal scales contain explicit feedback loops which may modify ecosystem dynamics and linkages between ecosystems and the atmosphere. The long-term change in climate, resulting from increased atmospheric concentrations of greenhouse gases (e.g., CO2, CH4, and nitrous oxide (N2O)) will further modify the global environment and potentially induce further ecosystem change. Modeling these interactions requires coupling successional models to biogeochemical models to

  6. Impacts of Species Interactions on Atmospheric Processes

    Science.gov (United States)

    Lerdau, M.; Wang, B.; Cook, B.; Neu, J. L.; Schimel, D.

    2016-12-01

    atmosphere. We propose a general framework for considering higher order ecological interactions in models of biosphere/atmosphere exchange and air quality. We also demonstrate that secular trends in the global environment, e.g., anthropogenic warming, may alter these interactions and subsequent VOC emissions.

  7. the Martian atmospheric boundary layer

    DEFF Research Database (Denmark)

    Petrosyan, A.; Galperin, B.; Larsen, Søren Ejling

    2011-01-01

    The planetary boundary layer (PBL) represents the part of the atmosphere that is strongly influenced by the presence of the underlying surface and mediates the key interactions between the atmosphere and the surface. On Mars, this represents the lowest 10 km of the atmosphere during the daytime...... atmosphere. To date, this region of the atmosphere has been studied directly, by instrumented lander spacecraft, and from orbital remote sensing, though not to the extent that is necessary to fully constrain its character and behavior. Current data strongly suggest that as for the Earth's PBL, classical...... of the modeling techniques used for the PBL on Earth are also being applied to the Martian PBL, including novel uses of very high resolution large eddy simulation methods. We conclude with those aspects of the PBL that require new measurements in order to constrain models and discuss the extent to which...

  8. Mars Atmospheric History Derived from Upper-Atmospheric Structure of 38Ar/36Ar Measured From MAVEN

    Science.gov (United States)

    Jakosky, Bruce; Slipski, Marek; Benna, Mehdi; Mahaffy, Paul; Elrod, Meredith K.; Yelle, Roger; Stone, Shane; Alsaeed, Noora

    2016-10-01

    Measurements of the structure of the Martian upper atmosphere made from MAVEN observations allow us to derive homopause and exobase altitudes in the Mars upper atmosphere and to determine the isotopic fractionation that occurs between them. Fractionation in the ratio of 38Ar/36Ar occurs between the homopause and exobase due to diffusive separation. This fractionation, combined with measurements of the bulk atmospheric ratio, is used to determine the total amount of argon lost to space by pick-up-ion sputtering. Our analysis is based on Rayleigh distillation, modified by replenishment of gas to the atmosphere by outgassing, impact, and crustal weathering. Approximately 80 % of the 36Ar that was ever in the atmosphere has been removed through time. This high value requires that a major fraction of Mars atmospheric gas has been lost to space. It points strongly to loss to space as having been the dominant mechanism driving the transition in Martian climate from an early, warm, wet environment to today's cold, dry, thin atmosphere.

  9. Ambiente atmosférico urbano e admissão hospitalar de crianças, na cidade de São Paulo, Brasil Urban atmospheric environment and hospital admission for children in the city of Sao Paulo, Brazil Ambiente atmosférico urbano e ingresos hospitalarios de niños en la ciudad de Sâo Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Edelci Nunes da Silva

    2013-06-01

    bioclimatic index PET (Physiological Equivalent Temperature with hospital admissions. A total of 12,269 admissions of children for respiratory causes were analysed - CID 10, Chapter 10: Respiratory diseases (J00-J32; J40-J47; J80-J99. Daily data about the average, lowest and highest air temperatures (ºC, relative humidity (% and wind speed (m/s were obtained from the meteorological station of Congonhas airport. For control purposes, the air quality indexes were obtained from CETESB (the Sao Paulo State body for transferring technology and monitoring the environment and water quality in Congonhas. Descriptive statistical analysis and regression models were used. Data were organized following a socio-environmental profile. Results indicate a statistical association between atmospheric variables, air pollution, and hospital admissions. There were no significant differences for the group of children with respiratory diseases living in districts with different environmental conditions. Los cambios climáticos constituyen un riesgo para la salud pública. No obstante, pocos estudios han tratado de identificar cómo la dinámica meteorológica afecta a la salud a fin de obtener datos para alimentar modelos de prevención de riesgos. En las ciudades tropicales, estos estudios resultan particularmente escasos. Esta investigación tuvo como objetivo verificar en qué medida las condiciones atmosféricas urbanas afectan a la salud respiratoria de los niños menores de cinco años en el sector sursureste de la ciudad de São Paulo, relacionando las variables meteorológicas y el índice bioclimático PET (Physiological Equivalent Temperature con los ingresos hospitalarios. Se analizaron 12 269 casos de ingresos de niños por enfermedades respiratorias - CIE 10, Capítulo 10 - Enfermedades Respiratorias (J00-J32; J40-J47; J80-J99. Las temperaturas medias, mínima y máxima diarias (ºC, la humedad relativa del aire (% y la velocidad media del viento (m/s fueron obtenidas en la estaci

  10. FASCODE for the environment (FASE)

    Energy Technology Data Exchange (ETDEWEB)

    Snell, H.E.; Moncet, J.L. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States); Anderson, G.P.; Chetwynd, J.H. [Phillips Lab., Hanscom AFM, MD (United States)] [and others

    1996-04-01

    The Optical Physics Division of the Phillips Laboratory, with support from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program, is developing a state-of-the-art line-by-line atmospheric radiative transfer model as the successor to FASCODE. The goal of this project is to create a computationally efficient model which contains the most up-to-date atmospheric physics. The new model, known as FASCODE for the Environment, or {open_quotes}FASE{close_quotes}, will combine the best features of FASCODE and LBLRTM, the DOE`s standard radiative transfer model. FASE will also contain new features such as new cross-sections for heavy molecules, and improved solar irradiance model, and improvements to the Schumann-Runge bands and continuum. The code will be optimized for vectorized and/or parallel processing. put under configuration control for easy maintenance, and structured into separate modules for each function: atmospheric profiles, layer optical properties, radiative transfer, multiple-scattering, etc. This modular structure will allow for increased flexibility and easy customization of the code for specialized applications, such as a forward model for iterative inversion algorithms. Ease-of-use will be enhanced with improved input control structures and documentation to accommodate the needs of novice and advanced users. This paper addresses changes which have been made to FASCODE and LBLRTM to create FASE, and gives an overview of the modular structure and its capabilities.

  11. Radiation Environment of Phobos

    Science.gov (United States)

    Cooper, John F.; Clark, John H.; Sturner, Steven J.; Stubbs, Timothy; Wang, Yongli; Glenar, David A.; Schwadron, Nathan A.; Joyce, Colin J.; Spence, Harlan E.; Farrell, William M.

    2017-10-01

    The innermost Martian moon Phobos is a potential way station for the human exploration of Mars and the solar system beyond the orbit of Mars. It has a similar radiation environment to that at 1 AU for hot plasma and more energetic particles from solar, heliospheric and galactic sources. In the past two decades there have been many spacecraft measurements at 1 AU, and occasionally in the Mars orbital region around the Sun, that can be used to define a reference model for the time-averaged and time-variable radiation environments at Mars and Phobos. Yearly to hourly variance comes from the eleven-year solar activity cycle and its impact on solar energetic, heliospheric, and solar-modulated galactic cosmic ray particles. We report progress on compilation of the reference model from U.S. and international spacecraft data sources of the NASA Space Physics Data Facility and the Virtual Energetic Particle Observatory (VEPO), and from tissue-equivalent dosage rate measurements by the CRaTER instrument on the Lunar Reconnaissance Observer spacecraft now in lunar orbit. Similar dosage rate data are also available from the Mars surface via the NASA Planetary Data System archive from the Radiation Assessment Detector (RAD) instrument aboard the Mars Science Laboratory (MSL) Curiosity rover. The sub-Mars surface hemisphere of Phobos is slightly blocked from energetic particle irradiation by the body of Mars but there is a greater global variance of interplanetary radiation exposure as we have calculated from the known topography of this irregularly shaped moon. Phobos receives a relatively small flux of secondary radiation from galactic cosmic ray interactions with the Mars surface and atmosphere, and at plasma energies from pickup ions escaping out of the Mars atmosphere. The greater secondary radiation source is from cosmic ray interactions with the moon surface, which we have simulated with the GEANT radiation transport code for various cases of the surface regolith

  12. Determination of the atmospheric neutrino fluxes from atmospheric neutrino data

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, C.; Maltoni, M.; Rojo, J.

    2006-06-01

    The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray. In this work we present an alternative approach to the determination of the atmospheric neutrino fluxes based on the direct extraction from the experimental data on neutrino event rates. The extraction is achieved by means of a combination of artificial neural networks as interpolants and Monte Carlo methods for faithful error estimation. (author)

  13. Atmospheric stability and atmospheric circulation in Athens, Greece

    International Nuclear Information System (INIS)

    Synodinou, B.M.; Petrakis, M.; Kassomenos, P.; Lykoudis, S.

    1996-01-01

    In the evaluation and study of atmospheric pollution reference is always made to the stability criteria. These criteria, usually represented as functions of different meteorological data such as wind speed and direction, temperature, solar radiation, etc., play a very important role in the investigation of different parameters that affect the build up of pollution episodes mainly in urban areas. In this paper an attempt is made to evaluate the atmospheric stability criteria based on measurements obtained from two locations in and nearby Athens. The atmospheric stability is then examined along with the other meteorological parameters

  14. MARCS model atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Plez, B [GRAAL, CNRS, UMR5024, Universite Montpellier 2, F-34095 Montpellier, Cedex 5 (France) and Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden)], E-mail: bertrand.plez@graal.univ-montp2.fr

    2008-12-15

    In this review presented at the Symposium A Stellar Journey in Uppsala, June 2008, I give an account of the historical development of the MARCS code, and its premises from the first version published in 1975 to the 2008 grid. The primary driver for the development team who constantly strive to include the best possible physical data, is the science that can be done with the models. A few preliminary comparisons of M star model spectra to spectrophotometric observations are presented. Particular results related to opacity effects are discussed. The size of errors in spectral energy distribution (SED) and model thermal stratification is estimated for different densities of wavelength sampling. The number of points used in the MARCS 2008 grid (108 000) is large enough to ensure errors of only a few K in all models of the grid, except the optically very thin layers of metal-poor stars. Errors in SEDs may reach about 10% locally in the UV. The published sampled SEDs are thus adequate to compute synthetic broadband photometry, but higher resolution spectra will be computed in the near future and published as well on the MARCS site (marcs.astro.uu.se). Test model calculations with TiO line opacity accounted for in scattering show significant cooling of the upper atmospheric layers of red giants. Rough estimates of radiative and collisional time scales for electronic transitions of TiO indicate that scattering may well be the dominant mechanism in these lines. However, models constructed with this hypothesis are incompatible with optical observations of TiO (Arcturus) or IR observations of OH (Betelgeuse), although they may succeed in explaining H{sub 2}O line observations. More work is needed in that direction.

  15. What makes urban atmospheric chemistry different and special?

    Science.gov (United States)

    Harrison, Roy M.

    2016-04-01

    There has been a tendency in the atmospheric chemistry community to regard urban atmospheric chemistry as no different to global processes and to differentiate only in terms of the emissions density in models. Such an approach may be suitable for assessing the impact of urban emissions upon regional and global processes but is unsuited to generating a clear understanding of processes within the urban atmosphere itself. The urban atmosphere differentiates itself from the global atmosphere in terms of its density of emissions and relatively short timescales for chemical reaction processes, a consequence of which is that the key processes in the urban atmosphere are often different from those in the regional and remote atmosphere. This lecture will give relevant examples. One of the key aspects of both urban and rural/remote atmospheres is the oxidation of primary pollutants and the formation of secondary species. Such processes may differ markedly between urban and non-urban environments as there are major differences in the behaviour of key oxidants such as ozone, hydroxyl and NO3 radical. In the remote atmosphere the key production process for hydroxyl is through the photolysis of ozone to form excited state oxygen atoms which react with water vapour to form OH. In the urban atmosphere, concentrations of ozone are typically depressed relative to the rural atmosphere and hence this source of OH is less favourable. There are likely to be much higher concentrations of both nitrous acid and formaldehyde in the urban atmosphere whose photolysis is probably the major source of OH. Additionally, there is far more possibility for nocturnal formation of OH in the urban atmosphere from reactions of Criegee intermediates resulting from the oxidation of alkenes. As a consequence, it has been shown that winter to summer ratios of hydroxyl radical concentrations are much higher in the urban atmosphere than is typical of rural atmospheres in northern mid-latitudes. In rural

  16. Characterization of the Marine Atmosphere for Free-Space Optical Communication

    National Research Council Canada - National Science Library

    Thomas, Linda M. Wasiczko; Moore, Christopher I; Burris, Harris R; Suite, Michele; Stell, Mena; Murphy, James; Gilbreath, G. C; Rabinovich, William; Scharpf, William

    2006-01-01

    The Chesapeake Bay Detachment of the Naval Research Laboratory (NRL-CBD) provides an ideal environment for characterizing the effects of the marine atmosphere on free space optical communication links...

  17. Simulation of Venus Atmosphere Dynamics With an Earth Climate GCM

    Science.gov (United States)

    Parish, H. F.; Schubert, G.; Covey, C. C.; Grossman, A.

    2008-12-01

    We describe the results of initial simulations of the Venusian atmosphere, using the Community Atmosphere Model (CAM). The CAM model is a descendant of the NCAR Community Climate Model, and is defined as one of two "high-end" models designated by the US Climate Change Science Program for basic research. It may also be the most widely used 3D climate model in the US. CAM has grown substantially in complexity and Earth-specificity since the original version was released in 1983, and many of these Earth based physics parameterizations need to be adjusted to simulate the Venus atmosphere. Other groups are adapting CAM to simulate the atmospheres of Mars and Titan, thereby promising CAM simulation for all four terrestrial planets known to have substantial atmospheres. Studying these worlds together will provide calibration of Earth-centric studies of climate changes like global warming. It will also provide context for future searches for Earth-like planets orbiting other stars. In this work we will focus on Venus. The Venus atmosphere represents an extreme environment, strongly influenced by the greenhouse effect, and studying the Venus atmosphere may therefore be relevant to the possible future direction of the Earth's climate. The dynamical processes which occur in the Venusian atmosphere are not well understood, including the cause of the strong superrotation of the atmosphere, in which the planetary surface rotates with a period of around 243 days, but the atmosphere near the cloud tops has a rotational period of only around 4 days. We show the results of initial simulations of the dynamics of the Venus atmosphere, using a version of the CAM model with most of the Earth related processes, such as the cloud physics, removed. A simplified form of heating has been applied, similar to the thermal forcing approach used recently by other authors. We investigate the sensitivity of the model results to changes in the physics parameterizations we have used, including

  18. Hydrodynamics of oceans and atmospheres

    CERN Document Server

    Eckart, Carl

    1960-01-01

    Hydrodynamics of Oceans and Atmospheres is a systematic account of the hydrodynamics of oceans and atmospheres. Topics covered range from the thermodynamic functions of an ideal gas and the thermodynamic coefficients for water to steady motions, the isothermal atmosphere, the thermocline, and the thermosphere. Perturbation equations, field equations, residual equations, and a general theory of rays are also presented. This book is comprised of 17 chapters and begins with an introduction to the basic equations and their solutions, with the aim of illustrating the laws of dynamics. The nonlinear

  19. Atmospheres of the terrestrial planets

    International Nuclear Information System (INIS)

    Kivelson, M.G.; Schubert, G.

    1986-01-01

    Properties of the planets are identified - such as size, spin rate, and distance from the sun - that are important in understanding the characteristics of their atmospheres. Venus, earth and Mars have surface-temperature differences only partly explained by the decrease of solar radiation flux with distance from the sun. More significant effects arise from the variations in the degree to which the atmospheres act as absorbers of planetary thermal reradiation. Atmospheric circulation on a global scale also varies markedly among the three planets. 5 references

  20. Saturn: atmosphere, ionosphere, and magnetosphere.

    Science.gov (United States)

    Gombosi, Tamas I; Ingersoll, Andrew P

    2010-03-19

    The Cassini spacecraft has been in orbit around Saturn since 30 June 2004, yielding a wealth of data about the Saturn system. This review focuses on the atmosphere and magnetosphere and briefly outlines the state of our knowledge after the Cassini prime mission. The mission has addressed a host of fundamental questions: What processes control the physics, chemistry, and dynamics of the atmosphere? Where does the magnetospheric plasma come from? What are the physical processes coupling the ionosphere and magnetosphere? And, what are the rotation rates of Saturn's atmosphere and magnetosphere?

  1. Environment, pollution and growing health hazards

    International Nuclear Information System (INIS)

    Mehmud, S.

    1987-01-01

    The atmosphere surround the planet like a mantle and compositions of atmosphere also changes. The role of high concentration in the stratosphere is vital in as much as it act as a very effective filter for absorbing ultraviolet rays. Different type of wastes that is industrial waste, domestic waste, etc. are being mixed in the environment. The procedure for monitoring pollution in the atmosphere involves the use of a laser radar (LIDAR). Laser beam is sent out in the atmosphere and point of the laser beam back-scattered by the pollutants. Aerosols to the laser radar which receives and processes it with the help of a high speed digital computer. (A.B.)

  2. Mars Environment and Magnetic Orbiter model payload

    DEFF Research Database (Denmark)

    Langlais, B.; Leblanc, F.; Fouchet, T.

    2009-01-01

    Mars Environment and Magnetic Orbiter was proposed as an answer to the Cosmic Vision Call of Opportunity as a M-class mission. The MEMO mission is designed to study the strong interconnections between the planetary interior, atmosphere and solar conditions essential to understand planetary...

  3. The speciation of iodine in the environment

    International Nuclear Information System (INIS)

    Bulman, R.A.

    1986-01-01

    The speciation of iodine in the environment is discussed under the following topics: (i) sea surface to atmosphere, (ii) chemistry in bulk seawater, (iii) iodine in rocks, (iv) iodine in soils, (v) iodine in plants and (vi) iodine in solidified wastes. (author)

  4. Characterization of extra-solar planets and their atmospheres (Spectroscopy of transits and atmospheric escape)

    International Nuclear Information System (INIS)

    Bourrier, Vincent

    2014-01-01

    Hot Jupiters are exo-planets so close to their star that their atmosphere can lose gas because of hydrodynamic escape. Transiting gaseous giants are an excellent way to understand this mechanism, but it is necessary to study other types of planets to determine its impact on the exo-planetary population. This thesis aims at using transit spectroscopy to observe the atmosphere of several exo-planets, to study their properties and to contribute to the characterization of hydrodynamic escape. UV lines observed with the Hubble telescope are analyzed with the numerical model of upper atmospheres we developed. Using the Ly-α line we identify energetic and dynamical interactions between the atmospheres of the hot Jupiters HD209458b and HD189733b and their stars. We study the dependence of the escape on the environment of a planet and on its physical properties, through the observation of a super-Earth and a warm Jupiter in the 55 Cnc system. Using observations of HD209458b, we show that magnesium lines are a window on the region of formation of hydrodynamic escape. We study the potential of transit spectroscopy in the near-UV to detect new cases of atmospheric escape. This mechanism is fostered by the proximity of a planet to its star, which makes it even more important to understand the formation and migration processes that can be traced in the alignment of a planetary system. Using measures from the spectrographs HARPS-N and SOPHIE we study the alignments of 55 Cnc e and the Kepler candidate KOI 12.01, whose planetary nature we also seek to validate. (author)

  5. Atmospheric moisture supersaturation in the near-surface atmosphere at Dome C, Antarctic Plateau

    Science.gov (United States)

    Genthon, Christophe; Piard, Luc; Vignon, Etienne; Madeleine, Jean-Baptiste; Casado, Mathieu; Gallée, Hubert

    2017-01-01

    Supersaturation often occurs at the top of the troposphere where cirrus clouds form, but is comparatively unusual near the surface where the air is generally warmer and laden with liquid and/or ice condensation nuclei. One exception is the surface of the high Antarctic Plateau. One year of atmospheric moisture measurement at the surface of Dome C on the East Antarctic Plateau is presented. The measurements are obtained using commercial hygrometry sensors modified to allow air sampling without affecting the moisture content, even in the case of supersaturation. Supersaturation is found to be very frequent. Common unadapted hygrometry sensors generally fail to report supersaturation, and most reports of atmospheric moisture on the Antarctic Plateau are thus likely biased low. The measurements are compared with results from two models implementing cold microphysics parameterizations: the European Center for Medium-range Weather Forecasts through its operational analyses, and the Model Atmosphérique Régional. As in the observations, supersaturation is frequent in the models but the statistical distribution differs both between models and observations and between the two models, leaving much room for model improvement. This is unlikely to strongly affect estimations of surface sublimation because supersaturation is more frequent as temperature is lower, and moisture quantities and thus water fluxes are small anyway. Ignoring supersaturation may be a more serious issue when considering water isotopes, a tracer of phase change and temperature, largely used to reconstruct past climates and environments from ice cores. Because observations are easier in the surface atmosphere, longer and more continuous in situ observation series of atmospheric supersaturation can be obtained than higher in the atmosphere to test parameterizations of cold microphysics, such as those used in the formation of high-altitude cirrus clouds in meteorological and climate models.

  6. Atmospheric moisture supersaturatons in the near-surface atmosphere of Dome C, Antarctic Plateau

    Science.gov (United States)

    Genthon, Christophe; Piard, Luc; Vignon, Etienne; Madeleine, Jean-Baptiste; Casado, Mathieu; Gallée, Hubert

    2017-04-01

    Moisture supersaturations occur at the top of the troposphere where cirrus clouds form, but is comparatively unusual near the surface where the air is generally warmer and laden with liquid and/or ice condensation nuclei. One exception is the surface of the high antarctic plateau. This study presents one year of atmospheric moisture measurement at the surface of Dome C on the East Antarctic plateau. The measurements are obtained using commercial hygrometry sensors adapted to allow air sampling without affecting the moisture content even in case of supersaturation. Supersaturation is found to be very frequent. Common unadapted hygrometry sensors generally fail to report supersaturation, and most reports of atmospheric moisture on the antarctic plateau are thus likely biased low. The measurements are compared with results from 2 models with cold microphysics parametrizations: the European Center for Medium-range Weather Forecasts through its operational analyses, and the Model Atmosphérique Régional. As in the observations, supersaturation is frequent in the models but the statistical distribution differs both between models and observations and between the 2 models, leaving much room for model improvement. The representation of supersaturations is not critical for the estimations of surface sublimation since they are more frequent as temperature is lower i.e. as moisture quantities and water fluxes are small. However, ignoring near-surface supersaturation may be a more serious issue for the modeling of fog and when considering water isotopes, a tracer of phase change and temperature, largely used to reconstruct past climates and environments from ice cores. Because observations are easier in the surface atmosphere, longer and more continuous in situ observation series of atmospheric supersaturation can be obtained than higher in the atmosphere to test parameterizations of cold microphysics, such as those used in the formation of high altitude cirrus clouds in

  7. Atmospheric Research 2014 Technical Highlights

    Science.gov (United States)

    Platnick, Steven

    2015-01-01

    Atmospheric research in the Earth Sciences Division (610) consists of research and technology development programs dedicated to advancing knowledge and understanding of the atmosphere and its interaction with the climate of Earth. The Division's goals are to improve understanding of the dynamics and physical properties of precipitation, clouds, and aerosols; atmospheric chemistry, including the role of natural and anthropogenic trace species on the ozone balance in the stratosphere and the troposphere; and radiative properties of Earth's atmosphere and the influence of solar variability on the Earth's climate. Major research activities are carried out in the Mesoscale Atmospheric Processes Laboratory, the Climate and Radiation Laboratory, the Atmospheric Chemistry and Dynamics Laboratory, and the Wallops Field Support Office. The overall scope of the research covers an end-to-end process, starting with the identification of scientific problems, leading to observation requirements for remote-sensing platforms, technology and retrieval algorithm development; followed by flight projects and satellite missions; and eventually, resulting in data processing, analyses of measurements, and dissemination from flight projects and missions. Instrument scientists conceive, design, develop, and implement ultraviolet, infrared, optical, radar, laser, and lidar technology to remotely sense the atmosphere. Members of the various Laboratories conduct field measurements for satellite sensor calibration and data validation, and carry out numerous modeling activities. These modeling activities include climate model simulations, modeling the chemistry and transport of trace species on regional-to-global scales, cloud resolving models, and developing the next-generation Earth system models. Satellite missions, field campaigns, peer-reviewed publications, and successful proposals are essential at every stage of the research process to meeting our goals and maintaining leadership of the

  8. Sonic anemometry of planetary atmospheres

    Science.gov (United States)

    Cuerva, Alvaro; Sanz-Andrés, Angel; Lorenz, Ralph D.

    2004-02-01

    Sonic anemometers are robust, fast and reliable wind sensors which are able to measure the complete wind speed vector at high sampling rates. All these characteristics make sonic anemometers to be ideal candidates for atmospheric applications. Since sonic anemometers have not moving parts and they can be designed to have loss mass and power consumption, they have become adequate for planetary exploration purposes, both for atmosphere studies and for flying robot control. However, some challenges must be undertaken before implementing their use. Problems such as sound attenuation in different atmospheres, sensor/air acoustic impedance matching as well as flow/fluid dependence of sonic measurements have to be considered when these sensors are used in other atmospheres.

  9. Martian Atmospheric and Ionospheric plasma Escape

    Science.gov (United States)

    Lundin, Rickard

    2016-04-01

    Solar forcing is responsible for the heating, ionization, photochemistry, and erosion processes in the upper atmosphere throughout the lifetime of the terrestrial planets. Of the four terrestrial planets, the Earth is the only one with a fully developed biosphere, while our kin Venus and Mars have evolved into arid inhabitable planets. As for Mars, there are ample evidences for an early Noachian, water rich period on Mars. The question is, what made Mars evolve so differently compared to the Earth? Various hydrosphere and atmospheric evolution scenarios for Mars have been forwarded based on surface morphology, chemical composition, simulations, semi-empiric (in-situ data) models, and the long-term evolution of the Sun. Progress has been made, but the case is still open regarding the changes that led to the present arid surface and tenuous atmosphere at Mars. This presentation addresses the long-term variability of the Sun, the solar forcing impact on the Martian atmosphere, and its interaction with the space environment - an electromagnetic wave and particle interaction with the upper atmosphere that has implications for its photochemistry, composition, and energization that governs thermal and non-thermal escape. Non-thermal escape implies an electromagnetic upward energization of planetary ions and molecules to velocities above escape velocity, a process governed by a combination of solar EUV radiation (ionization), and energy and momentum transfer by the solar wind. The ion escape issue dates back to the early Soviet and US-missions to Mars, but the first more accurate estimates of escape rates came with the Phobos-2 mission in 1989. Better-quality ion composition measurement results of atmospheric/ionospheric ion escape from Mars, obtained from ESA Mars Express (MEX) instruments, have improved our understanding of the ion escape mechanism. With the NASA MAVEN spacecraft orbiting Mars since Sept. 2014, dual in-situ measurement with plasma instruments are now

  10. Pesticides in the atmosphere: distribution, trends, and governing factors

    Science.gov (United States)

    Majewski, Michael S.; Capel, Paul D.

    1996-01-01

    Most people know about the presence and health effects of pesticide residues in the water they drink. However, they may not realize the impact of atmospheric transportation and deposition of pesticides on water quality. Scientific studies of pesticides in various atmospheric matrices (air, rain, snow, aerosols, and fog) provide some of the answers. Pesticides in the Atmosphere focuses on the review and interpretation of direct measurements of pesticides in the environment. An exhaustive compilation, the book examines hundreds of studies in detailed tabular listings, with accompanying maps that include such features as spatial and temporal domain studies, target analytes, detection limits, and compounds detected. Working with the foundation of forty years of scientific studies, the editors synthesize this research to characterize the common threads and main conclusions. They use this information to identify where we need to improve our understanding of pesticides in the atmosphere and their significance to water quality. Pesticides in the Atmosphere serves as a resource, text, and reference to a wide spectrum of scientists, water managers, and students. It includes extensive compilations of references, interpretive analyses and conclusions. For those not familiar with the atmospheric transportation and deposition of pesticides it provides a comprehensive introduction.

  11. Copper patinas formed in different atmospheres and exposure times

    International Nuclear Information System (INIS)

    Lobo, V.M.M.; Almeida, M.E.; Balmayor, M.; Tomas, H.M.L.R.

    1998-01-01

    Atmospheric corrosion products in copper samples, known as patinas, formed in industrial-marine, severe-marine and rural atmospheres exposed for 1,2,3, and 4 years, have been studied. The nature and structure of the products formed, characterized by X-ray diffraction (XRD) and infrared spectrometry (FTIR) depend on the time of exposure and the type of atmosphere. Copper patinas have been extensively mentioned in the literature, but the structural nature of their compounds, which vary according to the time of exposure and types of atmospheres, is still not adequately described in the literature. In order to give a contribution to this area, copper panels were exposed for 1,2,3, and 4 years in different types of atmospheres representing situations commonly observed, and subsequently the patinas were studied by XRD and FTIR 150 mm x 1 mm copper panels from commercial copper were exposed to three different atmospheric conditions in Portugal: industrial-marine (Leixoes, near Oporto, highly industrialized city close to the Ocean, subject to SO 2 from refineries); rural (Pego, small village in rural environment). The panels, attached to the appropriate stands, in accordance with ISO 8565 (1), were exposed for periods of 1,2,3 and 4 years, adequately collected for laboratory analysis by infrared spectrometry (FTIR). (Author)

  12. Analysis of smoke trailers at individual classes of atmosphere stability

    International Nuclear Information System (INIS)

    Carach, V.; Macala, J.

    2007-01-01

    At the present most endangered element of the environment is currently atmosphere and its pollution that rapidly accrue. Pollutants are emitted from air pollution sources. The output of pollutant from air pollution source is creating so-called smoke screen. Smoke screens can be observed from point sources of air pollution - smokestacks, up-cast. The purpose of this article was to build theoretical models of smoke screens rise from point source at different meteorological conditions characterized with fifth classes of atmosphere stability. (authors)

  13. Aspects of atmospheric turbulence related to scintillometry

    NARCIS (Netherlands)

    Braam, M.

    2014-01-01

    Aspects of atmospheric turbulence related to scintillometry Atmospheric turbulence is the main vertical transport mechanism in the atmospheric boundary layer. The surface fluxes related to this turbulent transport are the sensible (

  14. Atmospheric Chemistry and Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Ehhalt, D.; Prather, M.; Dentener, F.; Derwent, R.; Dlugokencky, Edward J.; Holland, E.; Isaksen, I.; Katima, J.; Kirchhoff, V.; Matson, P.; Midgley, P.; Wang, M.; Berntsen, T.; Bey, I.; Brasseur, G.; Buja, L.; Collins, W. J.; Daniel, J. S.; DeMore, W. B.; Derek, N.; Dickerson, R.; Etheridge, D.; Feichter, J.; Fraser, P.; Friedl, R.; Fuglestvedt, J.; Gauss, M.; Grenfell, L.; Grubler, Arnulf; Harris, N.; Hauglustaine, D.; Horowitz, L.; Jackman, C.; Jacob, D.; Jaegle, L.; Jain, Atul K.; Kanakidou, M.; Karlsdottir, S.; Ko, M.; Kurylo, M.; Lawrence, M.; Logan, J. A.; Manning, M.; Mauzerall, D.; McConnell, J.; Mickley, L. J.; Montzka, S.; Muller, J. F.; Olivier, J.; Pickering, K.; Pitari, G.; Roelofs, G.-J.; Rogers, H.; Rognerud, B.; Smith, Steven J.; Solomon, S.; Staehelin, J.; Steele, P.; Stevenson, D. S.; Sundet, J.; Thompson, A.; van Weele, M.; von Kuhlmann, R.; Wang, Y.; Weisenstein, D. K.; Wigley, T. M.; Wild, O.; Wuebbles, D.J.; Yantosca, R.; Joos, Fortunat; McFarland, M.

    2001-10-01

    Chapter 4 of the IPCC Third Assessment Report Climate Change 2001: The Scientific Basis. Sections include: Executive Summary 2414.1 Introduction 2434.2 Trace Gases: Current Observations, Trends and Budgets 2484.3 Projections of Future Emissions 2664.4 Projections of Atmospheric Composition for the 21st Century 2674.5 Open Questions 2774.6 Overall Impact of Global Atmospheric Chemistry Change 279

  15. Radionuclide dispersion in the atmosphere

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Amorim, E.S. do; Panetta, J.

    1979-05-01

    The instantaneous liberation of radionuclides in the atmosphere is studied in three dimensions, according to the formalism of the diffusion theory. The analytical solution, expose to gravitational and an atmospherical effects, is combined with the discretization of space and time in the calculation of levels of exposure. A typical inventory (for a PWR) was considered in the calculation of immersion doses, and the results permitted a comparative analysis among the different existing models. (Author) [pt

  16. Atmospheric science and power production

    Energy Technology Data Exchange (ETDEWEB)

    Randerson, D. (ed.)

    1984-07-01

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  17. Atmospheric Research 2016 Technical Highlights

    Science.gov (United States)

    Platnick, Steven

    2017-01-01

    Atmospheric research in the Earth Sciences Division (610) consists of research and technology development programs dedicated to advancing knowledge and understanding of the atmosphere and its interaction with the climate of Earth. The Divisions goals are to improve understanding of the dynamics and physical properties of precipitation, clouds, and aerosols; atmospheric chemistry, including the role of natural and anthropogenic trace species on the ozone balance in the stratosphere and the troposphere; and radiative properties of Earth's atmosphere and the influence of solar variability on the Earth's climate. Major research activities are carried out in the Mesoscale Atmospheric Processes Laboratory, the Climate and Radiation Laboratory, the Atmospheric Chemistry and Dynamics Laboratory, and the Wallops Field Support Office. The overall scope of the research covers an end-to-end process, starting with the identification of scientific problems, leading to observation requirements for remote-sensing platforms, technology and retrieval algorithm development; followed by flight projects and satellite missions; and eventually, resulting in data processing, analyses of measurements, and dissemination from flight projects and missions. Instrument scientists conceive, design, develop, and implement ultraviolet, infrared, optical, radar, laser, and lidar technology to remotely sense the atmosphere. Members of the various laboratories conduct field measurements for satellite sensor calibration and data validation, and carry out numerous modeling activities. These modeling activities include climate model simulations, modeling the chemistry and transport of trace species on regional-to-global scales, cloud resolving models, and developing the next-generation Earth system models. Satellite missions, field campaigns, peer-reviewed publications, and successful proposals are essential at every stage of the research process to meeting our goals and maintaining leadership of the

  18. A synthesis of atmospheric mercury depletion event chemistry in the atmosphere and snow

    Directory of Open Access Journals (Sweden)

    A. J. Poulain

    2008-03-01

    Full Text Available It was discovered in 1995 that, during the spring time, unexpectedly low concentrations of gaseous elemental mercury (GEM occurred in the Arctic air. This was surprising for a pollutant known to have a long residence time in the atmosphere; however conditions appeared to exist in the Arctic that promoted this depletion of mercury (Hg. This phenomenon is termed atmospheric mercury depletion events (AMDEs and its discovery has revolutionized our understanding of the cycling of Hg in Polar Regions while stimulating a significant amount of research to understand its impact to this fragile ecosystem. Shortly after the discovery was made in Canada, AMDEs were confirmed to occur throughout the Arctic, sub-Artic and Antarctic coasts. It is now known that, through a series of photochemically initiated reactions involving halogens, GEM is converted to a more reactive species and is subsequently associated to particles in the air and/or deposited to the polar environment. AMDEs are a means by which Hg is transferred from the atmosphere to the environment that was previously unknown. In this article we review Hg research taken place in Polar Regions pertaining to AMDEs, the methods used to collect Hg in different environmental media, research results of the current understanding of AMDEs from field, laboratory and modeling work, how Hg cycles around the environment after AMDEs, gaps in our current knowledge and the future impacts that AMDEs may have on polar environments. The research presented has shown that while considerable improvements in methodology to measure Hg have been made but the main limitation remains knowing the speciation of Hg in the various media. The processes that drive AMDEs and how they occur are discussed. As well, the role that the snow pack and the sea ice play in the cycling of Hg is presented. It has been found that deposition of Hg from AMDEs occurs at marine coasts and not far inland and that a fraction of the deposited Hg does

  19. Calibration of atmospheric hydrogen measurements

    Directory of Open Access Journals (Sweden)

    A. Jordan

    2011-03-01

    Full Text Available Interest in atmospheric hydrogen (H2 has been growing in recent years with the prospect of H2 being a potential alternative to fossil fuels as an energy carrier. This has intensified research for a quantitative understanding of the atmospheric hydrogen cycle and its total budget, including the expansion of the global atmospheric measurement network. However, inconsistencies in published observational data constitute a major limitation in exploring such data sets. The discrepancies can be mainly attributed to difficulties in the calibration of the measurements. In this study various factors that may interfere with accurate quantification of atmospheric H2 were investigated including drifts of standard gases in high pressure cylinders. As an experimental basis a procedure to generate precise mixtures of H2 within the atmospheric concentration range was established. Application of this method has enabled a thorough linearity characterization of the commonly used GC-HgO reduction detector. We discovered that the detector response was sensitive to the composition of the matrix gas. Addressing these systematic errors, a new calibration scale has been generated defined by thirteen standards with dry air mole fractions ranging from 139–1226 nmol mol−1. This new scale has been accepted as the official World Meteorological Organisation's (WMO Global Atmospheric Watch (GAW H2 mole fraction scale.

  20. Impact of TPP on environment

    International Nuclear Information System (INIS)

    Krylov, D.A.

    2002-01-01

    Data on environmental impact and action on people health of enterprises of coal industry, and coal and natural gas TPP were analyzed. Volume of harmful substances discharge to the atmosphere on the replace of 30 billion m 3 of gas by the Kansko-Achinsk and Kuznetsk coal (for three variants of use) was calculated. The calculations presented that the drop of gas supply at TPP with the simultaneous increase of coal consumption could give rise to the significant growth of harmful discharges to the environment [ru

  1. Atmospheric Entry Experiments at IRS

    Science.gov (United States)

    Auweter-Kurtz, M.; Endlich, P.; Herdrich, G.; Kurtz, H.; Laux, T.; Löhle, S.; Nazina, N.; Pidan, S.

    2002-01-01

    Entering the atmosphere of celestial bodies, spacecrafts encounter gases at velocities of several km/s, thereby being subjected to great heat loads. The thermal protection systems and the environment (plasma) have to be investigated by means of computational and ground facility based simulations. For more than a decade, plasma wind tunnels at IRS have been used for the investigation of TPS materials. Nevertheless, ground tests and computer simulations cannot re- place space flights completely. Particularly, entry mission phases encounter challenging problems, such as hypersonic aerothermodynamics. Concerning the TPS, radiation-cooled materials used for reuseable spacecrafts and ablator tech- nologies are of importance. Besides the mentioned technologies, there is the goal to manage guidance navigation, con- trol, landing technology and inflatable technologies such as ballutes that aim to keep vehicles in the atmosphere without landing. The requirement to save mass and energy for planned interplanetary missions such as Mars Society Balloon Mission, Mars Sample Return Mission, Mars Express or Venus Sample Return mission led to the need for manoeuvres like aerocapture, aero-breaking and hyperbolic entries. All three are characterized by very high kinetic vehicle energies to be dissipated by the manoeuvre. In this field flight data are rare. The importance of these manoeuvres and the need to increase the knowledge of required TPS designs and behavior during such mission phases point out the need of flight experiments. As result of the experience within the plasma diagnostic tool development and the plasma wind tunnel data base, flight experiments like the PYrometric RE-entry EXperiment PYREX were developed, fully qualified and successfully flown. Flight experiments such as the entry spectrometer RESPECT and PYREX on HOPE-X are in the conceptual phase. To increase knowledge in the scope of atmospheric manoeuvres and entries, data bases have to be created combining both

  2. Atmospheric dispersion in nuclear power plant siting

    International Nuclear Information System (INIS)

    1980-01-01

    The atmosphere is an important pathway for the transport of radioactive releases from a nuclear power plant to the environment and thereby to man. It is necessary therefore to have adequate information about this pathway in order to estimate the dispersion of radioactive releases to the population in the region and thus be able to assess the radiological impact on man. The present Guide describes the meteorological phenomena and mechanisms involved in the dispersion of the released effluents in the atmosphere, discusses the methods which may be used to calculate the concentration and deposition in the region, specifies the data needed for input to these models, states the characteristics of the requisite instrumentation and data analysis systems and discusses certain related topics. Methods are presented for estimating concentration for short and long periods of emission over a wide range of types of radioactive releases. The evaluation of dose to individuals and population, given the concentration, is dealt with in national and international publications. It has been customary in the safety analysis of nuclear power plants to prepare dispersion estimates with different degrees of emphasis and various accuracy requirements at the stages of (a) site survey, (b) site evaluation, and (c) operation of the plant, and for accident contingency planning. Recommendations given in the present Guide generally apply to a distance of up to about 10 km depending upon the complexity of the terrain. The extension to longer distances may be made with caution and to the satisfaction of the regulatory authority

  3. Reassessing the atmospheric oxidation mechanism of toluene

    Science.gov (United States)

    Ji, Yuemeng; Zhao, Jun; Terazono, Hajime; Misawa, Kentaro; Levitt, Nicholas P.; Li, Yixin; Lin, Yun; Peng, Jianfei; Wang, Yuan; Duan, Lian; Pan, Bowen; Zhang, Fang; Feng, Xidan; An, Taicheng; Marrero-Ortiz, Wilmarie; Secrest, Jeremiah; Zhang, Annie L.; Shibuya, Kazuhiko; Molina, Mario J.; Zhang, Renyi

    2017-08-01

    Photochemical oxidation of aromatic hydrocarbons leads to tropospheric ozone and secondary organic aerosol (SOA) formation, with profound implications for air quality, human health, and climate. Toluene is the most abundant aromatic compound under urban environments, but its detailed chemical oxidation mechanism remains uncertain. From combined laboratory experiments and quantum chemical calculations, we show a toluene oxidation mechanism that is different from the one adopted in current atmospheric models. Our experimental work indicates a larger-than-expected branching ratio for cresols, but a negligible formation of ring-opening products (e.g., methylglyoxal). Quantum chemical calculations also demonstrate that cresols are much more stable than their corresponding peroxy radicals, and, for the most favorable OH (ortho) addition, the pathway of H extraction by O2 to form the cresol proceeds with a smaller barrier than O2 addition to form the peroxy radical. Our results reveal that phenolic (rather than peroxy radical) formation represents the dominant pathway for toluene oxidation, highlighting the necessity to reassess its role in ozone and SOA formation in the atmosphere.

  4. Atmospheric Ionizing Radiation (AIR) Project Review

    Science.gov (United States)

    Singleterry, R. C., Jr.; Wilson, J. W.; Whitehead, A. H.; Goldhagen, P. E.

    1999-01-01

    The National Council on Radiation Protection and Measurement (NCRP) and the National Academy of Science (NAS) established that the uncertainty in the data and models associated with the high-altitude radiation environment could and should be reduced. In response, the National Aeronautics and Space Administration (NASA) and the U.S. Department of Energy Environmental Measurements Laboratory (EML) created the Atmospheric Ionizing Radiation (AIR) Project under the auspices of the High Speed Research (HSR) Program Office at the Langley Research Center. NASA's HSR Program was developed to address the potential of a second-generation supersonic transport. A critical element focussed on the environmental issues, including the threat to crew and passengers posed by atmospheric radiation. Various international investigators were solicited to contribute instruments to fly on an ER-2 aircraft at altitudes similar to those proposed for the High Speed Civil Transport (HSCT). A list of participating investigators, their institutions, and instruments with quantities measured is presented. The flight series took place at solar minimum (radiation maximum) with northern, southern, and east/west flights. The investigators analyzed their data and presented preliminary results at the AIR Workshop in March, 1998. A review of these results are included.

  5. Reassessing the atmospheric oxidation mechanism of toluene.

    Science.gov (United States)

    Ji, Yuemeng; Zhao, Jun; Terazono, Hajime; Misawa, Kentaro; Levitt, Nicholas P; Li, Yixin; Lin, Yun; Peng, Jianfei; Wang, Yuan; Duan, Lian; Pan, Bowen; Zhang, Fang; Feng, Xidan; An, Taicheng; Marrero-Ortiz, Wilmarie; Secrest, Jeremiah; Zhang, Annie L; Shibuya, Kazuhiko; Molina, Mario J; Zhang, Renyi

    2017-08-01

    Photochemical oxidation of aromatic hydrocarbons leads to tropospheric ozone and secondary organic aerosol (SOA) formation, with profound implications for air quality, human health, and climate. Toluene is the most abundant aromatic compound under urban environments, but its detailed chemical oxidation mechanism remains uncertain. From combined laboratory experiments and quantum chemical calculations, we show a toluene oxidation mechanism that is different from the one adopted in current atmospheric models. Our experimental work indicates a larger-than-expected branching ratio for cresols, but a negligible formation of ring-opening products (e.g., methylglyoxal). Quantum chemical calculations also demonstrate that cresols are much more stable than their corresponding peroxy radicals, and, for the most favorable OH ( ortho ) addition, the pathway of H extraction by O 2 to form the cresol proceeds with a smaller barrier than O 2 addition to form the peroxy radical. Our results reveal that phenolic (rather than peroxy radical) formation represents the dominant pathway for toluene oxidation, highlighting the necessity to reassess its role in ozone and SOA formation in the atmosphere.

  6. Highly resolved measurements of atmospheric turbulence with the new 2d-Atmospheric Laser Cantilever Anemometer

    International Nuclear Information System (INIS)

    Jeromin, A; Schaffarczyk, A P; Puczylowski, J; Peinke, J; Hölling, M

    2014-01-01

    For the investigation of atmospheric turbulent flows on small scales a new anemometer was developed, the so-called 2d-Atmospheric Laser Cantilever Anemometer (2d-ALCA). It performs highly resolved measurements with a spatial resolution in millimeter range and temporal resolution in kHz range, thus detecting very small turbulent structures. The anemometer is a redesign of the successfully operating 2d-LCA for laboratory application. The new device was designed to withstand hostile operating environments (rain and saline, humid air). In February 2012, the 2d-ALCA was used for the first time in a test field. The device was mounted in about 53 m above ground level on a lattice tower near the German North Sea coast. Wind speed was measured by the 2d-ALCA at 10 kHz sampling rate and by cup anemometers at 1 Hz. The instantaneous wind speed ranged from 8 m/s to 19 m/s at an average turbulence level of about 7 %. Wind field characteristics were analyzed based on cup anemometer as well as 2d-ALCA. The combination of both devices allowed the study of atmospheric turbulence over several magnitudes in turbulent scales

  7. Environment and Medical Sciences Division Progress Report

    International Nuclear Information System (INIS)

    Hainge, W.M.

    1980-06-01

    The 1979 annual progress report of the UKAEA Environmental and Medical Sciences Division covers both radiological and non-nuclear research programmes in the environmental and toxicological fields. The specific topics were 1) 'atmospheric pollution' which included the analysis of atmospheric trace gases by gas chromatography/mass spectrometry, the life cycle of atmospheric sulphur compounds, photochemical pollution, studies on stratospheric reactions, stratospheric ozone and the effects of pollutants, upper air sampling and monitoring gaseous atmospheric pollutants with passive samplers; 2) miscellaneous 'environmental safety projects'; 3) 'radiation physics' projects concerning a) radioactive fallout, b) studies of stable trace elements in the atmospheric environment and studies of radioactivity in the environment, c) various aspects of dosimetry research including radiation biophysics, d) personnel dosimetry, e) applied radiation spectrometry and f) data systems; 5) 'aerosol and metabolic studies' including whole body counting studies; 6) 'inhalation toxicology and radionuclide analysis' studies including actinide inhalation, cytotoxicity and fibrogenicity of non-radioactive dusts, asbestos and glass fibre research, a Qauntimet 720 image analysis service and radionuclide analysis in biological materials; and 7) 'analytical services' used in relation to 'environmental safety and chemical analysis' projects. (U.K.)

  8. Characteristic of microplastics in the atmospheric fallout from Dongguan city, China: preliminary research and first evidence.

    Science.gov (United States)

    Cai, Liqi; Wang, Jundong; Peng, Jinping; Tan, Zhi; Zhan, Zhiwei; Tan, Xiangling; Chen, Qiuqiang

    2017-11-01

    Microplastic pollution has exhibited a global distribution, including seas, lakes, rivers, and terrestrial environment in recent years. However, little attention was paid on the atmospheric environment, though the fact that plastic debris can escape as wind-blown debris was previously reported. Thus, characteristics of microplastics in the atmospheric fallout from Dongguan city were preliminarily studied. Microplastics of three different polymers, i.e., PE, PP, and PS, were identified. Diverse shapes of microplastics including fiber, foam, fragment, and film were found, and fiber was the dominant shape of the microplastics. SEM images illustrated that adhering particles, grooves, pits, fractures, and flakes were the common patterns of degradation. The concentrations of non-fibrous microplastics and fibers ranged from 175 to 313 particles/m 2 /day in the atmospheric fallout. Thus, dust emission and deposition between atmosphere, land surface, and aquatic environment were associated with the transportation of microplastics.

  9. Atmospheric Downscaling using Genetic Programming

    Science.gov (United States)

    Zerenner, T.; Venema, V.; Simmer, C.

    2013-12-01

    The coupling of models for the different components of the soil-vegetation-atmosphere system is required to understand component interactions and feedback processes. The Transregional Collaborative Research Center 32 (TR 32) has developed a coupled modeling platform, TerrSysMP, consisting of the atmospheric model COSMO, the land-surface model CLM, and the hydrological model ParFlow. These component models are usually operated at different resolutions in space and time owing to the dominant processes. These different scales should also be considered in the coupling mode, because it is for instance unfeasible to run the computationally quite expensive atmospheric models at the usually much higher spatial resolution required by hydrological models. Thus up- and downscaling procedures are required at the interface between atmospheric model and land-surface/subsurface models. Here we present an advanced atmospheric downscaling scheme, that creates realistic fine-scale fields (e.g. 400 m resolution) of the atmospheric state variables from the coarse atmospheric model output (e.g. 2.8 km resolution). The mixed physical/statistical scheme is developed from a training data set of high-resolution atmospheric model runs covering a range different weather conditions using Genetic Programming (GP). GP originates from machine learning: From a set of functions (arithmetic expressions, IF-statements, etc.) and terminals (constants or variables) GP generates potential solutions to a given problem while minimizing a fitness or cost function. We use a multi-objective approach that aims at fitting spatial structures, spatially distributed variance and spatio-temporal correlation of the fields. We account for the spatio-temporal nature of the data in two ways. On the one hand we offer GP potential predictors, which are based on our physical understanding of the atmospheric processes involved (spatial and temporal gradients, etc.). On the other hand we include functions operating on

  10. Atmospheric Chemistry Over Southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  11. Radiation chemistry and the environment

    International Nuclear Information System (INIS)

    Getoff, F.

    1998-01-01

    The rather strong and many-sided pollution of the environment (atmosphere, water resources, soil) as a consequence of human activities is summarized. The solution of the arised problems by application of radiation chemistry methods and the utilization of modern environmentally ''clean'' and economical technologies, founded on electron beam processing, are mentioned. Some basic environmental problems and their solution are briefly discussed: i) Removal of CO 2 from flue gases and its radiation induced utilization. ii) Principals for degradation of aqueous pollutants by electron beam processing in the presence of ozone (synergistic effect). The radiation chemistry as a modern and manifold discipline with very broad applications can also essentially contribute in the conservation of the environment

  12. Space Weather, Environment and Societies

    CERN Document Server

    Lilensten, Jean

    2006-01-01

    Our planet exists within a space environment affected by constantly changing solar atmosphere producing cosmic particles and electromagnetic waves. This "space weather" profoundly influences the performance of our technology because we primarily use two means for transmitting information and energy; namely, electromagnetic waves and electricity. On an everyday basis, we have developed methods to cope with the normal conditions. However, the sun remains a fiery star whose 'angry' outbursts can potentially destroy spacecrafts, kill astronauts, melt electricity transformers, stop trains, and generally wreak havoc with human activities. Space Weather is the developing field within astronomy that aims at predicting the sun’s violent activity and minimizing the impacts on our daily lives. Space Weather, Environment, and Societies explains why our technological societies are so dependent on solar activity and how the Sun disturbs the transmission of information and energy. Footnotes expand specific points and the ...

  13. Radiation chemistry and the environment

    International Nuclear Information System (INIS)

    Getoff, Nikola

    1999-01-01

    The rather strong and many-sided pollution of the environment (atmosphere, water resources, soil) as a consequence of human activity is summarized. The solution of the arised problems by application of radiation chemistry methods and the utilization of modern environmentally 'clean' and economical technologies, founded on electron beam processing, are mentioned. Some basic environmental problems and their solution are briefly discussed. (i) Removal of CO 2 from flue gases and its radiation induced utilization. (ii) Principals for degradation of aqueous pollutants by electron beam processing in the presence of ozone (synergistic effect). The radiation chemistry as a modern and manifold discipline with very broad applications can also essentially contribute in the conservation of the environment

  14. Atmospheric benzenoid emissions from plants rival those from fossil fuels.

    Science.gov (United States)

    Misztal, P K; Hewitt, C N; Wildt, J; Blande, J D; Eller, A S D; Fares, S; Gentner, D R; Gilman, J B; Graus, M; Greenberg, J; Guenther, A B; Hansel, A; Harley, P; Huang, M; Jardine, K; Karl, T; Kaser, L; Keutsch, F N; Kiendler-Scharr, A; Kleist, E; Lerner, B M; Li, T; Mak, J; Nölscher, A C; Schnitzhofer, R; Sinha, V; Thornton, B; Warneke, C; Wegener, F; Werner, C; Williams, J; Worton, D R; Yassaa, N; Goldstein, A H

    2015-07-13

    Despite the known biochemical production of a range of aromatic compounds by plants and the presence of benzenoids in floral scents, the emissions of only a few benzenoid compounds have been reported from the biosphere to the atmosphere. Here, using evidence from measurements at aircraft, ecosystem, tree, branch and leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers, and phytoplankton) emits a wide variety of benzenoid compounds to the atmosphere at substantial rates. Controlled environment experiments show that plants are able to alter their metabolism to produce and release many benzenoids under stress conditions. The functions of these compounds remain unclear but may be related to chemical communication and protection against stress. We estimate the total global secondary organic aerosol potential from biogenic benzenoids to be similar to that from anthropogenic benzenoids (~10 Tg y(-1)), pointing to the importance of these natural emissions in atmospheric physics and chemistry.

  15. Estimating atmospheric temperature profile by an airborne microwave radiometer

    Science.gov (United States)

    Zhang, Jun; Xu, Jian; Kenntner, Mareike; Schreier, Franz; Doicu, Adrian

    2017-04-01

    As the rising atmospheric issues such as climate change, air pollution, and ozone depletion have extracted extensive attraction worldwide, observing and modeling of atmospheric quantities becomes critical to our understanding of the environment. This work focuses on the performance of an airborne passive microwave radiometer called MTP (Microwave Temperature Profiler). We aim to obtain vertically distributed atmospheric temperature from intensities measured by the instrument in terms of three frequencies and ten viewing angles. A retrieval program TIRAMISU (Temperature InveRsion Algorithm for MIcrowave SoUnding) has been utilized for processing the MTP data. To solve this severely ill-posed inverse problem, an analysis of different ways of constructing the penalty term onto the Tikhonov-type objective function is conducted. This numerical analysis can help us to better understand pros and cons of these regularization methods and to investigate the measurement capabilities of MTP.

  16. Chapter 4 Gaseous Elemental Mercury in the Ambient Atmosphere

    DEFF Research Database (Denmark)

    Ariya, Parisa A.; Skov, Henrik; Grage, Mette M L

    2008-01-01

    Understanding the kinetics and mechanisms associated with the atmospheric chemistry of mercury is of great importance to protecting the environment. This review will focus on theoretical calculations to advance understanding of gas phase oxidation of gaseous elemental mercury (GEM) by halogen...... species. Understanding the gas phase oxidation process between atmospheric mercury and halogen compounds is particularly important as all studies indicate that this interaction is the primary conversion mechanism in the troposphere leading to deposition of mercury. Theoretically predicting...... the thermochemistry of mercury containing species in the atmosphere is important because of the lack of experimental results. In this article a review of theoretical calculations of rate constants and reaction products is presented. Available laboratory data are listed and discussed as well in order to highlight...

  17. 85Kr distribution in the atmosphere and earth crust

    International Nuclear Information System (INIS)

    Belov, A.P.; Styro, B.I.

    1984-01-01

    A three-layer model of the 85 Kr stationary distribution in the atmosphere and in the earth's crust was considered. The 85 Kr concentration by height profile which existed before the artificial generation of the radionuclide was found. Quantitative evaluations of the anthropogenic 85 Kr releases due to the nuclear weapon tests and nuclear power engineering development and of the influence of the rereases on the steady-state 85 Kr distribution in the environment were given. It was shown that due to the atmospheric radionuclide releases a contamination with the 85 Kr of the near-surface layers of the earth's crust and of the surface waters occured. Calculations for the different dynamic states of the atmosphere were carried out and the influence of the 85 Kr washout coefficient on its vertical was analyzed

  18. An assessment of worldwide energy-related atmospheric pollution

    International Nuclear Information System (INIS)

    1989-01-01

    Energy-related emissions of atmospheric pollutants are currently suspected as the source of a number of major environmental problems. Early concerns about local and regional air quality and respiratory health risks, greatly alleviated in the case of sulfur dioxide (SO 2 ) emissions by the use of tall stacks, have been superseded by ''global problems,'' such as acidification of the biosphere, increase in tropospheric ozone (O 3 ), visibility impairment, long-term exposure to toxic pollutants, and buildup of ''greenhouse gases''. Chapter 1 assesses the sources and physical/chemical atmospheric processes of energy-related atmospheric pollution (ERAP). It is not an exhaustive review but rather a documented statement of the state-of-art knowledge on issues critical to effective environmental decision-making. Chapter 2 looks at the effects on man, the environment and materials, and chapter 3 presents an overview and policy options. (author)

  19. Energy and global environment

    International Nuclear Information System (INIS)

    Fyfe, W.S.; Powell, M.A.

    1991-01-01

    At present about 90% of the world's energy consumption is met by the fossil carbon fuel used in the form of coal, oil and natural gas. This results into release of vast amounts of waste gas CO 2 into the atmosphere posing a threat to the global environment. Moreover this energy source is not sustainable (renewable) and its use amounts to spending Earth's capital resources. The options to this energy source are biomass energy, hydro power, solar energy, geothermal energy and nuclear energy. The potentials, limitations, geological impact and environmental dangers, if any, of these sources are discussed in brief. Energy conservation through energy efficient systems is also one more option. Problems and potential for change to sustainable energy systems with respect to India and Canada are examined. Finally it is pointed out that the ultimate solution to the world's energy problem lies in population control and population reduction. This will make possible for the world to have a sustainable energy system primarily based on solar energy. (M.G.B.). 15 refs

  20. A theory of atmospheric oxygen.

    Science.gov (United States)

    Laakso, T A; Schrag, D P

    2017-05-01

    Geological records of atmospheric oxygen suggest that pO 2 was less than 0.001% of present atmospheric levels (PAL) during the Archean, increasing abruptly to a Proterozoic value between 0.1% and 10% PAL, and rising quickly to modern levels in the Phanerozoic. Using a simple model of the biogeochemical cycles of carbon, oxygen, sulfur, hydrogen, iron, and phosphorous, we demonstrate that there are three stable states for atmospheric oxygen, roughly corresponding to levels observed in the geological record. These stable states arise from a series of specific positive and negative feedbacks, requiring a large geochemical perturbation to the redox state to transition from one to another. In particular, we show that a very low oxygen level in the Archean (i.e., 10 -7 PAL) is consistent with the presence of oxygenic photosynthesis and a robust organic carbon cycle. We show that the Snowball Earth glaciations, which immediately precede both transitions, provide an appropriate transient increase in atmospheric oxygen to drive the atmosphere either from its Archean state to its Proterozoic state, or from its Proterozoic state to its Phanerozoic state. This hypothesis provides a mechanistic explanation for the apparent synchronicity of the Proterozoic Snowball Earth events with both the Great Oxidation Event, and the Neoproterozoic oxidation. © 2017 John Wiley & Sons Ltd.

  1. The Atmospheric Chemistry Experiment (ACE)

    International Nuclear Information System (INIS)

    Bernath, P.F.

    2017-01-01

    The Atmospheric Chemistry Experiment (ACE), also called SCISAT, is a Canadian-led small satellite mission for remote sensing of the Earth’s atmosphere. ACE was launched into a low Earth circular orbit by NASA on August 12, 2003 and it continues to function nominally. The ACE instruments are a high spectral resolution (0.02 cm −1 ) Fourier Transform Spectrometer (FTS) operating from 2.2 to 13.3 μm (750–4400 cm −1 ), a spectrophotometer known as Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) with wavelength coverage of 285–1020 nm and two filtered detector arrays to image the Sun at 0.525 and 1.02 μm. ACE operates in solar occultation mode to provide altitude profiles of temperature, pressure, atmospheric extinction and the volume mixing ratios (VMRs) for several dozen molecules and related isotopologues. This paper presents a mission overview and a summary of selected scientific results. - Highlights: • Overview of Atmospheric Chemistry Experiment (ACE) satellite mission. • Infrared and optical spectroscopy of the Earth's atmosphere by solar occultation. • Science highlights of ACE (also called SCISAT) mission.

  2. Venus Atmospheric Maneuverable Platform (VAMP)

    Science.gov (United States)

    Griffin, K.; Sokol, D.; Lee, G.; Dailey, D.; Polidan, R.

    2013-12-01

    We have explored a possible new approach to Venus upper atmosphere exploration by applying recent Northrop Grumman (non-NASA) development programs to the challenges associated with Venus upper atmosphere science missions. Our concept is a low ballistic coefficient (gas, wing span, vehicle mass, power supply, propulsion, materials considerations, structural elements, subsystems, and packaging. The interaction between the VAMP vehicle and the supporting orbiter will also be discussed. In this context, we will specifically focus upon four key factors impacting the design and performance of VAMP: 1. Feasibility of and options for the deployment of the vehicle in space 2. Entry into the Venus atmosphere, including descent profile, heat rate, total heat load, stagnation temperature, control, and entry into level flight 3. Characteristics of flight operations and performance in the Venus atmosphere: altitude range, latitude and longitude access, day/night performance, aircraft performance (aerodynamics, power required vs. power available, propulsion, speed, percent buoyancy), performance sensitivity to payload weight 4. Science payload accommodation, constraints, and opportunities We will discuss interdependencies of the above factors and the manner in which the VAMP strawman's characteristics affect the CONOPs and the science objectives. We will show how the these factors provide constraints as well as enable opportunities for novel long duration scientific studies of the Venus upper atmosphere that support VEXAG goals 2 and 3. We will also discuss how the VAMP platform itself can facilitate some of these science measurements.

  3. Atmospheric corrosion of mild steel

    Directory of Open Access Journals (Sweden)

    Morcillo, M.

    2011-10-01

    Full Text Available The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a the morphology of steel corrosion products and corrosion product layers; and b long-term atmospheric corrosion ( > 10 years.

    La corrosión atmosférica del acero suave es un tema de gran amplitud que ha sido tratado por muchos autores en numerosas regiones del mundo. Este artículo de compilación incorpora publicaciones relevantes sobre esta temática, en particular sobre la naturaleza de los productos de corrosión atmosférica, mecanismos y cinética de los procesos de corrosión atmosférica, prestando una atención especial a dos aspectos sobre los que la información publicada ha sido menos abundante: a morfología de los productos de corrosión del acero y capas de productos de corrosión, y b corrosión atmosférica a larga duración (> 10 años.

  4. Atmosphere in a Test Tube

    Science.gov (United States)

    Claudi, R.; Pace, E.; Ciaravella, A.; Micela, G.; Piccioni, G.; Billi, D.; Cestelli Guidi, M.; Coccola, L.; Erculiani, M. S.; Fedel, M.; Galletta, G.; Giro, E.; La Rocca, N.; Morosinotto, T.; Poletto, L.; Schierano, D.; Stefani, S.

    The ancestor philosophers' dream of thousand of new world is finally realised: more than 1800 extrasolar planets have been discovered in the neighborhood of our Sun. Most of them are very different from those we used to know in our Solar System. Others orbit the Habitable Zone (HZ) of their parent stars. Space missions, as JWST and the very recently proposed ARIEL, or ground based instruments, like SPHERE@VLT, GPI@GEMINI and EPICS@ELT, have been proposed and built to measure the atmospheric transmission, reflection and emission spectra over a wide wavelength range of these new worlds. In order to interpret the spectra coming out by this new instrumentation, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how those characteristics could be affected by radiation driven photochemical and bio-chemical reaction. Insights in this direction can be achieved from laboratory studies of simulated planetary atmosphere of different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. ''Atmosphere in a Test Tube'' is a collaboration among several Italian astronomical, biological and engineering institutes in order to share their experiencece in performing laboratory experiments on several items concerning extrasolar planet atmospheres.

  5. The effects of atmospheric pressure on infrared reflectance spectra of Martian analogs

    Science.gov (United States)

    Bishop, Janice L.; Pieters, Carle M.; Pratt, Stephen F.; Patterson, William

    1993-01-01

    The use of terrestrial samples as analogs of Mars soils are complicated by the Martian atmosphere. Spectral features due to the Martian atmosphere can be removed from telescopic spectra of Mars and ISM spectra of Mars, but this does not account for any spectral differences resulting from atmospheric pressure or any interactions between the atmosphere and the surface. We are examining the effects of atmospheric pressure on reflectance spectra of powdered samples in the laboratory. Contrary to a previous experiment with granite, no significant changes in albedo or the Christiansen feature were observed from 1 bar pressure down to a pressure of 8 micrometers Hg. However, reducing the atmospheric pressure does have a pronounced affect on the hydration features, even for samples retained in a dry environment for years.

  6. Towards a Global Unified Model of Europa's Tenuous Atmosphere

    Science.gov (United States)

    Plainaki, Christina; Cassidy, Tim A.; Shematovich, Valery I.; Milillo, Anna; Wurz, Peter; Vorburger, Audrey; Roth, Lorenz; Galli, André; Rubin, Martin; Blöcker, Aljona; Brandt, Pontus C.; Crary, Frank; Dandouras, Iannis; Jia, Xianzhe; Grassi, Davide; Hartogh, Paul; Lucchetti, Alice; McGrath, Melissa; Mangano, Valeria; Mura, Alessandro; Orsini, Stefano; Paranicas, Chris; Radioti, Aikaterini; Retherford, Kurt D.; Saur, Joachim; Teolis, Ben

    2018-02-01

    Despite the numerous modeling efforts of the past, our knowledge on the radiation-induced physical and chemical processes in Europa's tenuous atmosphere and on the exchange of material between the moon's surface and Jupiter's magnetosphere remains limited. In lack of an adequate number of in situ observations, the existence of a wide variety of models based on different scenarios and considerations has resulted in a fragmentary understanding of the interactions of the magnetospheric ion population with both the moon's icy surface and neutral gas envelope. Models show large discrepancy in the source and loss rates of the different constituents as well as in the determination of the spatial distribution of the atmosphere and its variation with time. The existence of several models based on very different approaches highlights the need of a detailed comparison among them with the final goal of developing a unified model of Europa's tenuous atmosphere. The availability to the science community of such a model could be of particular interest in view of the planning of the future mission observations (e.g., ESA's JUpiter ICy moons Explorer (JUICE) mission, and NASA's Europa Clipper mission). We review the existing models of Europa's tenuous atmosphere and discuss each of their derived characteristics of the neutral environment. We also discuss discrepancies among different models and the assumptions of the plasma environment in the vicinity of Europa. A summary of the existing observations of both the neutral and the plasma environments at Europa is also presented. The characteristics of a global unified model of the tenuous atmosphere are, then, discussed. Finally, we identify needed future experimental work in laboratories and propose some suitable observation strategies for upcoming missions.

  7. WINDII atmospheric wave airglow imaging

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T. [Los Alamos National Lab., NM (United States); Hoppe, U.-P. [Forsvarets Forskningsinstitutt, Kjeller (Norway); Solheim, B.H.; Shepherd, G.G. [York Univ., Toronto, ON (Canada). Inst. for Space and Terrestrial Science

    1996-12-31

    Preliminary WINDII nighttime airglow wave-imaging data in the UARS rolldown attitude has been analyzed with the goal to survey gravity waves near the upper boundary of the middle atmosphere. Wave analysis is performed on O[sub 2](0,0) emissions from a selected 1[sup 0] x 1[sup 0] oblique view of the airglow layer at approximately 95 km altitude, which has no direct earth background and only an atmospheric background which is optically thick for the 0[sub 2](0,0) emission. From a small data set, orbital imaging of atmospheric wave structures is demonstrated, with indication of large variations in wave activity across land and sea. Comparison ground-based imagery is discussed with respect to similarity of wave variations across land/sea boundaries and future orbital mosaic image construction.

  8. Terrestrial atmosphere, water and astrobiology

    Directory of Open Access Journals (Sweden)

    Coradini M.

    2010-12-01

    Full Text Available Primitive life, defined as a chemical system capable to transfer its molecular information via self-replication and also capable to evolve, originated about 4 billion years ago from the processing of organic molecules by liquid water. Terrestrial atmosphere played a key role in the process by allowing the permanent presence of liquid water and by participating in the production of carbon-based molecules. Water molecules exhibit specific properties mainly due to a dense network of hydrogen bonds. The carbon-based molecules were either home made in the atmosphere and/or in submarine hydrothermal systems or delivered by meteorites and micrometeorites. The search for possible places beyond the earth where the trilogy atmosphere/water/life could exist is the main objective of astrobiology. Within the Solar System, exploration missions are dedicated to Mars, Europa, Titan and the icy bodies. The discovery of several hundreds of extrasolar planets opens the quest to the whole Milky Way.

  9. An archetype hydrogen atmosphere problem

    International Nuclear Information System (INIS)

    Athay, R.G.; Mihalas, D.; Shine, R.A.

    1975-01-01

    Populations for the first three bound states and the continuum of hydrogen are determined for an isothermal, hydrostatic atmosphere at 20000K. The atmosphere is treated as being optically thin in the Balmer and Paschen continua and illuminated by continuum radiation at these wavelengths with prescribed radiation temperatures. The atmosphere is optically thick in the 2-1,3-1,3-2 and c-1 transitions. Three stages of approximation are treated: (1) radiative detailed balance in the 2-1, 3-1 and 3-2 transitions, (2) radiative detailed balance in the 3-1 and 3-2 transitions, and (3) all transitions out of detailed balance. The solution of this problem is non-trivial, and presents sufficient difficulty to have caused failure of at least one rather standard technique. The problem is thus a good archetype against which new methods, or new implementations of old methods may be tested. (Auth.)

  10. An archetype hydrogen atmosphere problem

    Science.gov (United States)

    Athay, R. G.; Mihalas, D.; Shine, R. A.

    1975-01-01

    Populations for the first three bound states and the continuum of hydrogen are determined for an isothermal hydrostatic atmosphere at 20,000 K. The atmosphere is treated as optically thin in the Balmer and Paschen continua and illuminated by continuum radiation at these wavelengths with prescribed radiation temperatures. The atmosphere is optically thick in the 2-1, 3-1, 3-2 and c-1 transitions. Three stages of approximation are treated: (1) radiative detailed balance in the 2-1, 3-1 and 3-2 transitions, (2) radiative detailed balance in the 3-1 and 3-2 transitions, and (3) all transitions out of detailed balance. The solution of this problem is nontrivial and presents sufficient difficulty to have caused the failure of at least one rather standard technique. The problem is thus a good archetype against which new methods or new implementations of old methods may be tested.

  11. Atmospheric radon: origin and transfer

    Energy Technology Data Exchange (ETDEWEB)

    Segovia, N.; Tamez, E.; Pena, P.; Gaso, I. [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico); Mireles, F.; Davila, I.; Quirino, L. [Universidad Autonoma de Zacatecas (Mexico). Centro Regional de Estudios Nucleares

    1994-12-31

    Atmospheric indoor and outdoor radon surveys have been performed in several locations of Mexico. In order to estimate the radon transfer from different origins to the atmosphere, soil and ground water, together with the exhalation rate from bare and coated building materials have also been studied. The radon detection was performed with SSNTD, an automatic silicon-based radon monitor and the liquid scintillation technique. The results from several years of monitoring indicate that the atmospheric radon behaviour is different for the countryside as compared with more complex inhabited regions; transfer from soil being inhibited by the specific structures of the cities. The effect of wall coatings reduced from 50% to 90% the radon exhalation from bare building materials. A low radon content was observed in the ground water samples studied. (Author).

  12. Atmospheres of Jupiter and Saturn

    International Nuclear Information System (INIS)

    Hunt, G.E.

    1981-01-01

    In this paper the current knowledge of the atmospheres of Jupiter and Saturn are reviewed making use of the extensive telescopic studies, International Ultraviolet Explorer Satellite observations and the measurements made during the recent Pioneer and Voyager flybys which have been supported by detailed theoretical studies. A detailed discussion is given of the composition of these atmospheres and the abundance ratios which provide insight into their original state and their evolution. The Voyager observations indicate a surprisingly close similarity between the weather systems of the Earth and the giant planets. Although both Jupiter and Saturn have internal heat sources, and are therefore star-like in their interiors, they appear to produce terrestrial-style weather systems. A detailed discussion is given of this work, which forms a major study of the Laboratory for Planetary Atmospheres at University College London. (author)

  13. The modern research environment

    DEFF Research Database (Denmark)

    Topsøe, Flemming

    1993-01-01

    Information Technology, research environment, structured documents, networked information retrieval......Information Technology, research environment, structured documents, networked information retrieval...

  14. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    its weak gravity, the atmospheric molecules gradu- ally escaped, resulting in the very thin atmosphere existing now. To see if a thick atmosphere could be retained or not, we assume that the air hav- ing pressure of 1atmosphere (as exists on Earth now) existed on the Moon initially and calculate the escape life times for ...

  15. Fairweather atmospheric electricity at Antarctica during local ...

    Indian Academy of Sciences (India)

    Apart from the day-to-day variation in low latitude thunderstorm activity, there are diurnal, seasonal, inter-annual ... Atmospheric sciences; climate; upper atmosphere; global electric circuit; thunderstorm; Antarctica; atmospheric electricity; fairweather ... tribute to meteorological noise in the measured atmospheric electric ...

  16. Atmosphere revitalization for manned spacecraft - An assessment of technology readiness

    Science.gov (United States)

    Samonski, F. H., Jr.; Neel, J. M.

    1973-01-01

    The level of proficiency attained by the most effective physical and chemical regenerative processes capable of providing a habitable atmospheric environment in a spacecraft is assessed. It is shown that both the Sabatier and Bosh reactions are in a mature stage of technological readiness and can effectively reduce the carbon dioxide in a spacecraft. An electrochemical method for concentrating CO2 from an air environment offers promise to approach low levels of pCO2 control. Technological advances in the fields of solid polymer electrolytes and oxygen evolution electrocatalysts have led to a water electrolysis system that can maintain efficient performance for several years. Nitrogen supply and control of the composition of the spacecraft atmosphere is effectively provided by the circulating electrolyte technique.

  17. Atmospheric environmental implications of propulsion systems

    Science.gov (United States)

    Mcdonald, Allan J.; Bennett, Robert R.

    1995-01-01

    Three independent studies have been conducted for assessing the impact of rocket launches on the earth's environment. These studies have addressed issues of acid rain in the troposphere, ozone depletion in the stratosphere, toxicity of chemical rocket exhaust products, and the potential impact on global warming from carbon dioxide emissions from rocket launches. Local, regional, and global impact assessments were examined and compared with both natural sources and anthropogenic sources of known atmospheric pollutants with the following conclusions: (1) Neither solid nor liquid rocket launches have a significant impact on the earth's global environment, and there is no real significant difference between the two. (2) Regional and local atmospheric impacts are more significant than global impacts, but quickly return to normal background conditions within a few hours after launch. And (3) vastly increased space launch activities equivalent to 50 U.S. Space Shuttles or 50 Russian Energia launches per year would not significantly impact these conclusions. However, these assessments, for the most part, are based upon homogeneous gas phase chemistry analysis; heterogeneous chemistry from exhaust particulates, such as aluminum oxide, ice contrails, soot, etc., and the influence of plume temperature and afterburning of fuel-rich exhaust products, need to be further addressed. It was the consensus of these studies that computer modeling of interactive plume chemistry with the atmosphere needs to be improved and computer models need to be verified with experimental data. Rocket exhaust plume chemistry can be modified with propellant reformulation and changes in operating conditions, but, based upon the current state of knowledge, it does not appear that significant environmental improvements from propellant formulation changes can be made or are warranted. Flight safety, reliability, and cost improvements are paramount for any new rocket system, and these important aspects

  18. Atmospheric peroxides. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein-Lloyd, J.

    1994-08-01

    The research conducted in this program has furthered the development of a method for real-time analysis of hydrogen peroxide, methyl hydroperoxide, and hydroxymethyl hydroperoxide, the most abundant peroxides in the atmosphere. The Fenton method was used in a number of major field studies and the results used to test models of atmospheric photochemistry and observed diurnal profiles have shed light on the mechanism of formation of H2O2 and organic peroxides. The technique has also been adapted for analysis of peroxides in precipitation in an undergraduate analytical chemistry/instrumental analysis course.

  19. Stellar atmosphere in statistical equilibrium

    International Nuclear Information System (INIS)

    Kalkofen, W.; Klein, R.I.

    1979-01-01

    A static atmosphere with only Lyman continuum radiation in radiative equilibrium is studied for the effectsof radiative and collisional ionization on deviations from local thermodynamic equilibrium (LTE). Large increases and decreases of the kinetic temperature (range in Tapprox. factor 2) and, correspondingly, very large over- and underpopulation of the bound state (range in bapprox. factor 10 6 ) are found, depending on the frequency dependence of the photoionization cross section. Despite these large deviations from LTE, which strongly modify the emergent spectrum, there is almost no effect on the particle densities, the degree of ionization, and the basic structure of the atmosphere

  20. Plume spread and atmospheric stability

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The horizontal spread of a plume in atmospheric dispersion can be described by the standard deviation of horizontal direction. The widely used Pasquill-Gifford classes of atmospheric stability have assigned typical values of the standard deviation of horizontal wind direction and of the lapse rate. A measured lapse rate can thus be used to estimate the standard deviation of wind direction. It is examined by means of a large dataset of fast wind measurements how good these estimates are. (author) 1 fig., 2 refs.

  1. Characterizing Convection in Stellar Atmospheres

    International Nuclear Information System (INIS)

    Tanner, Joel; Basu, Sarbani; Demarque, Pierre; Robinson, Frank

    2011-01-01

    We perform 3D radiative hydrodynamic simulations to study the properties of convection in the superadiabatic layer of stars. The simulations show differences in both the stratification and turbulent quantities for different types of stars. We extract turbulent pressure and eddy sizes, as well as the T-τ relation for different stars and find that they are sensitive to the energy flux and gravity. We also show that contrary to what is usually assumed in the field of stellar atmospheres, the structure and gas dynamics of simulations of turbulent atmospheres cannot be parameterized with T eff and log(g) alone.

  2. Atmospheric contaminant sensor, book 1

    Science.gov (United States)

    Scott, B. W.; Stuart, J. H.

    1972-01-01

    Design and fabrication of a mass spectrometer system for use as an atmospheric monitor by submarine is reported. The performance design goals are presented. The operation of the system is essentially automatic, providing continuous display of the partial pressures of the principal atmospheric constituents and a pushbutton update display of two freon trace contaminants. The freon update cycle takes 15 or 30 seconds, depending on which are measured. Trouble free, long term, reliable operation, and ease of maintenance are the primary system requirements. The requirement of the freon detection with high sensitivity and high resolution made redesign of the overall analyzer housing and magnet necessary.

  3. Atmospheric-pressure plasma technology

    Science.gov (United States)

    Kogelschatz, U.

    2004-12-01

    Major industrial plasma processes operating close to atmospheric pressure are discussed. Applications of thermal plasmas include electric arc furnaces and plasma torches for generation of powders, for spraying refractory materials, for cutting and welding and for destruction of hazardous waste. Other applications include miniature circuit breakers and electrical discharge machining. Non-equilibrium cold plasmas at atmospheric pressure are obtained in corona discharges used in electrostatic precipitators and in dielectric-barrier discharges used for generation of ozone, for pollution control and for surface treatment. More recent applications include UV excimer lamps, mercury-free fluorescent lamps and flat plasma displays.

  4. Atmospheric Carbon Tetrachloride -- A Conundrum?

    Science.gov (United States)

    Mondeel, D. J.; Butler, J. H.; Montzka, S. A.; Hall, B. D.; King, D. B.; Yvon-Lewis, S. A.; Dutton, G. S.; Thompson, T. M.; Elkins, J. W.

    2003-12-01

    Carbon tetrachloride (CCl4) is a significant ozone-depleting gas in the atmosphere that has been decreasing in concentration at just under 1 ppt y-1 (Substances that Deplete Stratospheric Ozone. The rate of decline, however, is inconsistent with available information regarding the production and atmospheric lifetime of this gas. Other useful information for CCl4 is in the interhemispheric difference, which has changed little since the initial turnover in mixing ratio. This is unlike that of the CFCs and methyl chloroform (CH3CCl3), for which the interhemispheric difference in mixing ratio has become smaller, in some cases rapidly, with the decline in emissions in the mid-1990s. This suggests that emissions of CCl4 continue to be significant, particularly in light of the lowered estimates for the atmospheric lifetime of CCl4. This seeming paradox raises a number of questions, not just regarding production and emission, but also about the calculated lifetimes of atmospheric trace gases. The lifetime of CCl4 from losses solely within the atmosphere currently is calculated at 35(21-43 ) y. Recently reported losses to the ocean have reduced the lifetime estimate to 26(17-36) y and an even more recent estimate of losses to soils reduces the lifetime further to 20(13-32) y. These newly reported losses of CCl4 force a re-examination of the magnitudes and distributions of the sources and sinks of this gas. This poster presents some new data and an evaluation of what is known and unknown with regard to the budget of atmospheric CCl4, highlighting uncertainties and the need for additional research to reduce them. Montzka, S. A., et al., Controlled substances and other source gases, Chapter 1, in Scientific Assessment of Ozone Depletion: 2002, Global Ozone Res. and Monitor. Proj., Vol. No. 47, World Meteorol. Organ., Geneva, Switzerland, 2003. Yvon-Lewis, S. A., and J. H. Butler, Effect of oceanic uptake on atmospheric lifetimes of selected trace gases, J. Geophys. Res., 107(D

  5. Venus Global Reference Atmospheric Model

    Science.gov (United States)

    Justh, Hilary L.

    2017-01-01

    Venus Global Reference Atmospheric Model (Venus-GRAM) is an engineering-level atmospheric model developed by MSFC that is widely used for diverse mission applications including: Systems design; Performance analysis; Operations planning for aerobraking, Entry, Descent and Landing, and aerocapture; Is not a forecast model; Outputs include density, temperature, pressure, wind components, and chemical composition; Provides dispersions of thermodynamic parameters, winds, and density; Optional trajectory and auxiliary profile input files Has been used in multiple studies and proposals including NASA Engineering and Safety Center (NESC) Autonomous Aerobraking and various Discovery proposals; Released in 2005; Available at: https://software.nasa.gov/software/MFS-32314-1.

  6. Atmospheric corrosion of mild steel in the Niger Delta region of ...

    African Journals Online (AJOL)

    The atmospheric corrosion of Calabar, Cross River State environment has been investigated for 12 months using weight loss technique. The extent of pollution of the environment was also determined via measurements of the precipitation and air quality parameters. Apart from the suspended particulate matter (SPM) ...

  7. atmospheric corrosion of mild steel in the niger delta region of ...

    African Journals Online (AJOL)

    xtz

    ABSTRACT. The atmospheric corrosion of Calabar, Cross River State environment has been investigated for 12 months using weight loss technique. The extent of pollution of the environment was also determined via measurements of the precipitation and air quality parameters. Apart from the suspended particulate.

  8. Application of year-round atmospheric transmission data, collected with the MSRT multiband transmissometer during the FATMOSE trial in the False Bay area

    NARCIS (Netherlands)

    Jong, A.N. de; Eijk, A.M.J. van; Cohen, L.H.; Fritz, P.J.; Gunter, W.H.; Vrahimisb, G.; Faith, J.

    2011-01-01

    The FATMOSE trial (False Bay Atmospheric Experiment) is a continuation of the cooperative work between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment (South Africa). The atmospheric transmission, being of major importance for target

  9. International Conference on Environment Science (ICES 2012)

    CERN Document Server

    Advances in Computational Environment Science

    2012-01-01

    2012 International Conference on Environment Science and 2012 International Conference on Computer Science (ICES 2012/ICCS 2012) will be held in Australia, Melbourne, 15‐16 March, 2012.Volume 1 contains some new results in computational environment science. There are 47 papers were selected as the regular paper in this volume. It contains the latest developments and reflects the experience of many researchers working in different environments (universities, research centers or even industries), publishing new theories and solving new technological problems on computational environment science.   The purpose of volume 1 is interconnection of diverse scientific fields, the cultivation of every possible scientific collaboration, the exchange of views and the promotion of new research targets as well as the further dissemination, the dispersion, the diffusion of the environment science, including but not limited to Ecology, Physics, Chemistry, Biology, Soil Science, Geology, Atmospheric Science and Geography �...

  10. Atmospheric sciences division. Annual report, fiscal year 1981

    International Nuclear Information System (INIS)

    Raynor, G.S.

    1981-12-01

    The research activities of the Atmospheric Sciences Division of the Department of Energy and Environment for FY 1981 are presented. Facilities and major items of equipment are described. Research programs are summarized in three categories, modeling, field and laboratory experiments and data management and analysis. Each program is also described individually with title, principal investigator, sponsor and funding levels for FY 1981 and FY 1982. Future plans are summarized. Publications for FY 1981 are listed with abstracts. A list of personnel is included

  11. 3D Servicescape Model: Atmospheric Qualities of Virtual Reality Retailing

    OpenAIRE

    Dad, Aasim M; Davies, Barry J; Rehman, Asma Abdul

    2016-01-01

    The purpose of this paper is to provide a 3D servicescape conceptual model which explores the potential effect of 3D virtual reality retail stores' environment on shoppers' behaviour. Extensive review of literature within two different domains, namely: servicescape models, and retail atmospherics, was carried out in order to propose a conceptual model. Further, eight detailed interviews were conducted to confirm the stimulus dimension of the conceptual model. A 3D servicescape conceptual mode...

  12. Atmospheric characterization on the Kennedy Space Center Shuttle Landing Facility

    Science.gov (United States)

    Ko, Jonathan; Coffaro, Joseph; Wu, Chensheng; Paulson, Daniel; Davis, Christopher

    2017-08-01

    Large temperature gradients are a known source of strong atmospheric turbulence conditions. Often times these areas of strong turbulence conditions are also accompanied by conditions that make it difficult to conduct long term optical atmospheric tests. The Shuttle Landing Facility (SLF) at the Kennedy Space Center (KSC) provides a prime testing environment that is capable of generating strong atmospheric turbulence yet is also easily accessible for well instrumented testing. The Shuttle Landing Facility features a 5000 m long and 91 m wide concrete runway that provides ample space for measurements of atmospheric turbulence as well as the opportunity for large temperature gradients to form as the sun heats the surface. We present the results of a large aperture LED scintillometer, a triple aperture laser scintillometer, and a thermal probe system that were used to calculate a path averaged and a point calculation of Cn2. In addition, we present the results of the Plenoptic Sensor that was used to calculate a path averaged Cn2 value. These measurements were conducted over a multi-day continuous test with supporting atmospheric and weather data provided by the University of Central Florida.

  13. Perspectives on atmospheric-pressure plasmas for nanofabrication

    International Nuclear Information System (INIS)

    Mariotti, Davide; Sankaran, R Mohan

    2011-01-01

    Low-pressure, low-temperature plasmas are widely used for materials applications in industries ranging from electronics to medicine. To avoid the high costs associated with vacuum equipment, there has always been a strong motivation to operate plasmas at higher pressures, up to atmospheric. However, high-pressure operation of plasmas often leads to instabilities and gas heating, conditions that are unsuitable for materials applications. The recent development of microscale plasmas (i.e. microplasmas) has helped realize the sustainment of stable, non-thermal plasmas at atmospheric pressure and enable low-cost materials applications. There has also been an unexpected benefit of atmospheric-pressure operation: the potential to fabricate nanoscale materials which is not possible by more conventional, low-pressure plasmas. For example, in a high-pressure environment, nanoparticles can be nucleated in the gas phase from vapour (or solid metal) precursors. Alternatively, non-thermal, atmospheric-pressure plasmas can be coupled with liquids such as water or ethanol to nucleate and modify solution-phase nanoparticles. In this perspective paper, we review some of these recent efforts and provide an outlook for the rapidly emerging field of atmospheric-pressure plasmas for nanofabrication.

  14. Earth's mysterious atmosphere. ATLAS 1: Teachers guide with activities

    Science.gov (United States)

    1991-01-01

    One of our mission's primary goals is to better understand the physics and chemistry of our atmosphere, the thin envelope of air that provides for human life and shields us from the harshness of space. The Space Shuttle Atlantis will carry the ATLAS 1 science instruments 296 km above Earth, so that they can look down into and through the various layers of the atmosphere. Five solar radiometers will precisely measure the amount of energy the Sun injects into Earth's environment. The chemistry at different altitudes will be measured very accurately by five other instruments called spectrometers. Much of our time in the cockpit of Atlantis will be devoted to two very exciting instruments that measure the auroras and the atmosphere's electrical characteristics. Finally, our ultraviolet telescope will probe the secrets of fascinating celestial objects. This Teacher's Guide is designed as a detective story to help you appreciate some of the many questions currently studied by scientists around the world. Many complex factors affect our atmosphere today, possibly even changing the course of global climate. All of us who live on Earth must recognize that we play an ever-growing role in causing some of these changes. We must solve this great atmospheric mystery if we are to understand all these changes and know what to do about them.

  15. Observations of atmospheric ammonia from TANSO-FTS/GOSAT

    Science.gov (United States)

    Someya, Yu; Imasu, Ryoichi; Saitoh, Naoko; Shiomi, Kei

    2017-04-01

    Atmospheric ammonia has large impacts on the nitrogen cycles or atmospheric environment such as nucleation of PM2.5 particles. It is reported that ammonia in the atmosphere has been increasing rapidly with the growth of population globally and this trend must continue in the future. Satellite observation is an effective approach to get to know the global perspectives of the gas. Atmospheric ammonia is observable using the thermal infrared (TIR) spectra, and IASI, TES and CrIS had been revealed those distributions. GOSAT also has TIR band including the ammonia absorption bands. GOSAT has the shorter revisit cycle than that of the other hyper-spectral TIR sounders mentioned above, therefore, the shorter time-scale events can be represented. In addition to the importance of the impacts of ammonia itself, the concentration ratio between ammonia and the other trace gases such as CO which is one of the main targets of the GOSAT-2 project is useful as the indicator of their emission sources. In this study, we introduce an algorithm to retrieve the column amount of atmospheric ammonia based on non-linear optimal estimation (Rogers, 2000) from GOSAT spectra in the ammonia absorption band between 960 - 970 cm-1. Temperature and water vapor profiles are estimated in advance of the ammonia retrieval. The preliminary results showed significant high concentrations of ammonia in the Northern India and the Eastern China as pointed out in the previous researches. We will discuss the global distribution of ammonia in the presentation.

  16. Chemical Thermodynamics of Aqueous Atmospheric Aerosols: Modeling and Microfluidic Measurements

    Science.gov (United States)

    Nandy, L.; Dutcher, C. S.

    2017-12-01

    Accurate predictions of gas-liquid-solid equilibrium phase partitioning of atmospheric aerosols by thermodynamic modeling and measurements is critical for determining particle composition and internal structure at conditions relevant to the atmosphere. Organic acids that originate from biomass burning, and direct biogenic emission make up a significant fraction of the organic mass in atmospheric aerosol particles. In addition, inorganic compounds like ammonium sulfate and sea salt also exist in atmospheric aerosols, that results in a mixture of single, double or triple charged ions, and non-dissociated and partially dissociated organic acids. Statistical mechanics based on a multilayer adsorption isotherm model can be applied to these complex aqueous environments for predictions of thermodynamic properties. In this work, thermodynamic analytic predictive models are developed for multicomponent aqueous solutions (consisting of partially dissociating organic and inorganic acids, fully dissociating symmetric and asymmetric electrolytes, and neutral organic compounds) over the entire relative humidity range, that represent a significant advancement towards a fully predictive model. The model is also developed at varied temperatures for electrolytes and organic compounds the data for which are available at different temperatures. In addition to the modeling approach, water loss of multicomponent aerosol particles is measured by microfluidic experiments to parameterize and validate the model. In the experimental microfluidic measurements, atmospheric aerosol droplet chemical mimics (organic acids and secondary organic aerosol (SOA) samples) are generated in microfluidic channels and stored and imaged in passive traps until dehydration to study the influence of relative humidity and water loss on phase behavior.

  17. Influences of coupled fire-atmosphere interaction on wildfire behavior

    Science.gov (United States)

    Linn, R.; Winterkamp, J.; Jonko, A. K.; Runde, I.; Canfield, J.; Parsons, R.; Sieg, C.

    2017-12-01

    Two-way interactions between fire and the environment affect fire behavior at scales ranging from buoyancy-induced mixing and turbulence to fire-scale circulations that retard or increase fire spread. Advances in computing have created new opportunities for the exploration of coupled fire-atmosphere behavior using numerical models that represent interactions between the dominant processes driving wildfire behavior, including convective and radiative heat transfer, aerodynamic drag and buoyant response of the atmosphere to heat released by the fire. Such models are not practical for operational, faster-than-real-time fire prediction due to their computational and data requirements. However, they are valuable tools for exploring influences of fire-atmosphere feedbacks on fire behavior as they explicitly simulate atmospheric motions surrounding fires from meter to kilometer scales. We use the coupled fire-atmosphere model FIRETEC to gain new insights into aspects of fire behavior that have been observed in the field and laboratory, to carry out sensitivity analysis that is impractical through observations and to pose new hypotheses that can be tested experimentally. Specifically, we use FIRETEC to study the following multi-scale coupled fire-atmosphere interactions: 1) 3D fire-atmosphere interaction that dictates multi-scale fire line dynamics; 2) influence of vegetation heterogeneity and variability in wind fields on predictability of fire spread; 3) fundamental impacts of topography on fire spread. These numerical studies support new conceptual models for the dominant roles of multi-scale fluid dynamics in determining fire spread, including the roles of crosswind fire line-intensity variations on heat transfer to unburned fuels and the role of fire line depth expansion in upslope acceleration of fires.

  18. Sedimentation Efficiency of Condensation Clouds in Substellar Atmospheres

    Science.gov (United States)

    Gao, Peter; Marley, Mark S.; Ackerman, Andrew S.

    2018-03-01

    Condensation clouds in substellar atmospheres have been widely inferred from spectra and photometric variability. Up until now, their horizontally averaged vertical distribution and mean particle size have been largely characterized using models, one of which is the eddy diffusion–sedimentation model from Ackerman and Marley that relies on a sedimentation efficiency parameter, f sed, to determine the vertical extent of clouds in the atmosphere. However, the physical processes controlling the vertical structure of clouds in substellar atmospheres are not well understood. In this work, we derive trends in f sed across a large range of eddy diffusivities (K zz ), gravities, material properties, and cloud formation pathways by fitting cloud distributions calculated by a more detailed cloud microphysics model. We find that f sed is dependent on K zz , but not gravity, when K zz is held constant. f sed is most sensitive to the nucleation rate of cloud particles, as determined by material properties like surface energy and molecular weight. High surface energy materials form fewer, larger cloud particles, leading to large f sed (>1), and vice versa for materials with low surface energy. For cloud formation via heterogeneous nucleation, f sed is sensitive to the condensation nuclei flux and radius, connecting cloud formation in substellar atmospheres to the objects’ formation environments and other atmospheric aerosols. These insights could lead to improved cloud models that help us better understand substellar atmospheres. For example, we demonstrate that f sed could increase with increasing cloud base depth in an atmosphere, shedding light on the nature of the brown dwarf L/T transition.

  19. Applications of theoretical methods in atmospheric science

    DEFF Research Database (Denmark)

    Johnson, Matthew Stanley; Goodsite, Michael E.

    2008-01-01

    in addressing an issue of primary concern: understanding photochemical reaction rates at the various conditions found in the atmosphere. Atmospheric science includes both atmospheric chemistry and atmospheric physics, meteorology, climatology and the study of extraterrestrial atmospheres.......Theoretical chemistry involves explaining chemical phenomenon using natural laws. The primary tool of theoretical chemistry is quantum chemistry, and the field may be divided into electronic structure calculations, reaction dynamics and statistical mechanics. These three all play a role...

  20. Basic issues of atmospheric turbulence and turbulent diffusion

    International Nuclear Information System (INIS)

    Fortak, H.

    1985-01-01

    A major concern of the institutions commissioned with the protection of the environment is the prognostication of the environment's exposure to various pollutant emissions. The transport and turbulent diffusion of air-borne substances largely take place within a planetary boundary layer of a thickness between 500 to 1,500 m in which the atmosphere continues to be in a turbulent state of flow. The basic theories for the origination and formation of turbulence in flow fields, for the application of these theories to turbulent flows over complex terrain structures and, finally, for the turbulent diffusion of air-borne substances within the planetary boundary layer are presented. (orig./PW) [de