WorldWideScience

Sample records for atmospheric tracer experiments

  1. Atmospheric tracer experiments for regional dispersion studies

    International Nuclear Information System (INIS)

    Heffter, J.L.; Ferber, G.J.

    1980-01-01

    Tracer experiments are being conducted to verify atmospheric transport and dispersion calculations at distances from tens to hundreds of km from pollutant sources. In one study, a 2 1/2 year sampling program has been carried out at 13 sites located 30 to 140 km from a source of 85 Kr at the Savannah River Plant in South Carolina. Average weekly concentrations as well as twice-daily concentrations were obtained. Sampling data and meteorological data, including surface, tower, and rawinsonde observations are available on magnetic tape for model verification studies. Some verification results for the Air Resources Laboratories Atmospheric Transort and Dispersion Model (ARL-ATAD) are shown for averaging periods from one week to two years

  2. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1983-05-01

    The Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE) is a program designed to obtain data necessary to evaluate atmospheric transport and diffusion models used to calculate regional population doses caused by nuclear facility emissions to the atmosphere. This experiment will significantly improve the basis for evaluating the cost effectiveness of different methods of managing airborne nuclear wastes. During the period from March 1982 through September 1982, twice daily air samples have been collected at each of five sampling stations located on a radial from the SRP to Murray Hill, NJ (1000 km). Kr-85 emitted from the F and H area chemical separations facilities is being used as a tracer to determine the transport and diffusion of atmospheric releases from the SRP. The Kr-85 concentrations in the air samples will be compared with the calculated concentrations as predicted by the transport and diffusion models. The Kr-85 data and the meteorological data are being archived and will be made available to the modeling community

  3. Asian Tracer Experiment and Atmospheric Modeling (TEAM) Project: Draft Field Work Plan for the Asian Long-Range Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K Jerry; Flaherty, Julia E.

    2007-08-01

    This report provides an experimental plan for a proposed Asian long-range tracer study as part of the international Tracer Experiment and Atmospheric Modeling (TEAM) Project. The TEAM partners are China, Japan, South Korea and the United States. Optimal times of year to conduct the study, meteorological measurements needed, proposed tracer release locations, proposed tracer sampling locations and the proposed durations of tracer releases and subsequent sampling are given. Also given are the activities necessary to prepare for the study and the schedule for completing the preparation activities leading to conducting the actual field operations. This report is intended to provide the TEAM members with the information necessary for planning and conducting the Asian long-range tracer study. The experimental plan is proposed, at this time, to describe the efforts necessary to conduct the Asian long-range tracer study, and the plan will undoubtedly be revised and refined as the planning goes forward over the next year.

  4. Double tracer experiments to evaluate atmospheric transport and dose models

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Gryning, S.-E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

    1986-05-01

    Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released simultaneously from a 110-m stack and detected downwind at distances of 3-4 km. The experiments were made at the Swedish nuclear power plant Ringhals in 1981. The radioactive tracer was routine emissions from unit 1 (BWR). The one-hour measurements yielded crosswind profiles at ground level of SF 6 -concentrations and of gamma radiation from the plume. The measured profiles were compared to profiles calculated with computer models. The comparison showed that the models sometimes underestimate and sometimes overestimate the results, which seems to indicate that the models within their limited accuracy yield unbiased results. The ratios between measured and calculated values range from 0.2 to 3. The measurements revealed a surplus of gamma radiations from the noble gas daughters compared to those from the gases. This was interpreted as due to ground desposition and the estimated deposition velocities range from 2 to 10 cm/s. The meteorological conditions were monitored from a 100-m meteorological tower and from an 11-m mast. Measurements were made of wind speed, wind direction, and temperatures at different heights, and during each experiment a mini-radiosonde was released giving information on a possible inversion layer. The SF 6 -tracer was injected to the stack prior to the experiments. Air-samples were collected downwind in plastic bags by radio-controlled sampling units. The SF 6 -concentrations in the bags were determined with gas chromatography. Measurements of the gamma radiation from the plume were made with ionisation chambers and GM-counters. Furthermore, a few mobile gamma spectrometers were available giving information on the unscattered gamma radiation, thereby permitting identification of the radioactive isotopes. The work was partly financed by the Nuclear Safety Board of the Swedish Utilities and by the Danish association of utilities in Jutland and on Funen, Elsam

  5. Some atmospheric tracer experiments in complex terrain at LASL: experimental design and data

    International Nuclear Information System (INIS)

    Archuleta, J.; Barr, S.; Clements, W.E.; Gedayloo, T.; Wilson, S.K.

    1978-03-01

    Two series of atmospheric tracer experiments were conducted in complex terrain situations in and around the Los Alamos Scientific Laboratory. Fluorescent particle tracers were used to investigate nighttime drainage flow in Los Alamos Canyon and daytime flow across the local canyon-mesa complex. This report describes the details of these experiments and presents a summary of the data collected. A subsequent report will discuss the analysis of these data

  6. Atlantic Coast Unique Regional Atmospheric Tracer Experiment (ACURATE)

    International Nuclear Information System (INIS)

    Schubert, J.F.; Heffter, J.L.; Mead, G.A.

    1985-01-01

    A long-range, long-term data set on the regional scale for air pollution model was developed for evaluation. The ACURATE model used Kr-85 emitted intermittently from the Savannah River Plant as a tracer of hourly source emission data at 5 sites for a total of 3858 measurements

  7. A comparative modeling study of a dual tracer experiment in a large lysimeter under atmospheric conditions

    Science.gov (United States)

    Stumpp, C.; Nützmann, G.; Maciejewski, S.; Maloszewski, P.

    2009-09-01

    SummaryIn this paper, five model approaches with different physical and mathematical concepts varying in their model complexity and requirements were applied to identify the transport processes in the unsaturated zone. The applicability of these model approaches were compared and evaluated investigating two tracer breakthrough curves (bromide, deuterium) in a cropped, free-draining lysimeter experiment under natural atmospheric boundary conditions. The data set consisted of time series of water balance, depth resolved water contents, pressure heads and resident concentrations measured during 800 days. The tracer transport parameters were determined using a simple stochastic (stream tube model), three lumped parameter (constant water content model, multi-flow dispersion model, variable flow dispersion model) and a transient model approach. All of them were able to fit the tracer breakthrough curves. The identified transport parameters of each model approach were compared. Despite the differing physical and mathematical concepts the resulting parameters (mean water contents, mean water flux, dispersivities) of the five model approaches were all in the same range. The results indicate that the flow processes are also describable assuming steady state conditions. Homogeneous matrix flow is dominant and a small pore volume with enhanced flow velocities near saturation was identified with variable saturation flow and transport approach. The multi-flow dispersion model also identified preferential flow and additionally suggested a third less mobile flow component. Due to high fitting accuracy and parameter similarity all model approaches indicated reliable results.

  8. Feasibility of perfluorocarbon tracers (PFTs) in atmospheric source-receptor experiments

    International Nuclear Information System (INIS)

    Dietz, R.N.; Senum, G.I.

    1984-03-01

    A brief description of the perfluorocarbon tracer (PFT) system, which includes the tracers and the release equipment, the air samplers and the analyzers, is presented along with details on the research needs to provide a viable system for MATEX-scenario experiments. The present family of 2 viable PFTs needs to be increased to 5 to 6. Given the present precision of the analysis system, a one year long tracer experiment consisting of 4 hour releases every 60 hours from 5 different sites would require nearly 150 metric tons of PFTs at a cost of $15,000,000. Shortcomings in the programmable sampler include the pump, the sampling sequence control flexibility, data storage and retrieval, and the lack of remote communication capability; sampler adsorbent studies are also needed. The analytical system, including the catalyst processing bed, the chromatography column resolution, and the linearity of the detector, is in need of significant improvement. A higher resolution analysis system could significantly reduce analysis time but, more importantly, reduce tracer requirements more than 10-fold, for a cost savings potential of more than $13,000,000. A model is presented to demonstrate the feasibility of tracer material balances. Assessment of earlier long-range tracer experiments indicates the need for possibly 400 ground sampling sites requiring $8 to $14 million worth of samplers for a one-year tracer experiment. As many as six aircraft would be needed to conduct airborne model validation and material balance studies for each tracer plume

  9. The Shoreline Environment Atmospheric Dispersion Experiment (SEADEX): Meteorological and gas tracer data

    International Nuclear Information System (INIS)

    Johnson, W.B.; Cantrell, B.K.; Morley, B.M.; Uthe, E.E.; Nitz, K.C.

    1987-10-01

    The SEADEX atmospheric dispersion field study was conducted during the period May 28 to June 8, 1982, in northeastern Wisconsin, the vicinity of the Kewaunee Power Plant on the western shore of Lake Michigan. The specific objectives of SEADEX were to characterize (1) the atmospheric dispersion and (2) the meteorological conditions influencing this dispersion as completely as possible during the test period. This field study included a series of controlled tracer tests utilizing state-of-the-art tracer measurement technology to determine horizontal and vertical dispersion over both land and water. Extensive meteorological measurements were obtained to thoroughly characterize the three-dimensional structure of the atmospheric boundary controlling the dispersion process. This volume presents the meteorological and gas tracer data collected during the field study. 391 figs., 32 tabs

  10. Locating the Source of Atmospheric Contamination Based on Data From the Kori Field Tracer Experiment

    Directory of Open Access Journals (Sweden)

    Piotr Kopka

    2015-01-01

    Full Text Available Accidental releases of hazardous material into the atmosphere pose high risks to human health and the environment. Thus it would be valuable to develop an emergency reaction system which can recognize the probable location of the source based only on concentrations of the released substance as reported by a network of sensors. We apply a methodology combining Bayesian inference with Sequential Monte Carlo (SMC methods to the problem of locating the source of an atmospheric contaminant. The input data for this algorithm are the concentrations of a given substance gathered continuously in time. We employ this algorithm to locating a contamination source using data from a field tracer experiment covering the Kori nuclear site and conducted in May 2001. We use the second-order Closure Integrated PUFF Model (SCIPUFF of atmospheric dispersion as the forward model to predict concentrations at the sensors' locations. We demonstrate that the source of continuous contamination may be successfully located even in the very complicated, hilly terrain surrounding the Kori nuclear site. (original abstract

  11. Evaluation of three atmospheric dispersion models using tracer release experiment data

    International Nuclear Information System (INIS)

    Daoo, V.J.; Oza, R.B.; Pandit, G.G.; Sadasivan, S.; Venkat Raj, V.

    2004-01-01

    Performance of three atmospheric dispersion models viz: (1) Gaussian Plume Model (GPM), (2) Equi-Distance PUFF Model (EDPUFFM) and (3) Particle Trajectory Model (PTM) is evaluated using field data collected from a tracer (SF 6 ) release experiment. The experiment was conducted within the campus of the Bhabha Atomic Research Centre (BARC), located at Trombay, Mumbai, India. The three models used are currently in operation at the BARC. The first one is a standard, well-documented empirical model while the other two models have been developed at the Bhabha Atomic Research Centre. The PTM is a numerical model while the EDPUFFM is a hybrid model combining both the numerical and analytical techniques. The procedure for evaluation is as per the recommendations of 1980 AMS (American Meteorological Society) workshop on atmospheric dispersion models performance evaluation. In addition, linear regression analysis has also been carried out. The regression analysis reveals that on an average, the EDPUFFM and the GPM predictions are higher by a factor of about 1.5 while the PTM predictions are lower by a factor of about 4. Comparison of various performance measures reveals that the performance of the EDPUFFM is marginally better than that of the GPM while the PTM performance is comparatively poor. The uncertainty factors obtained in this study, especially for higher concentration range ( > 100 ppt) are similar to those obtained in other validation study carried out elsewhere to validate the GPM predictions. However, for lower concentration range and for the conditions after the source is switched off, all the three models perform poorly in predicting the concentration. (author)

  12. Iterative ensemble Kalman filter for atmospheric dispersion in nuclear accidents: An application to Kincaid tracer experiment.

    Science.gov (United States)

    Zhang, X L; Su, G F; Chen, J G; Raskob, W; Yuan, H Y; Huang, Q Y

    2015-10-30

    Information about atmospheric dispersion of radionuclides is vitally important for planning effective countermeasures during nuclear accidents. Results of dispersion models have high spatial and temporal resolutions, but they are not accurate enough due to the uncertain source term and the errors in meteorological data. Environmental measurements are more reliable, but they are scarce and unable to give forecasts. In this study, our newly proposed iterative ensemble Kalman filter (EnKF) data assimilation scheme is used to combine model results and environmental measurements. The system is thoroughly validated against the observations in the Kincaid tracer experiment. The initial first-guess emissions are assumed to be six magnitudes underestimated. The iterative EnKF system rapidly corrects the errors in the emission rate and wind data, thereby significantly improving the model results (>80% reduction of the normalized mean square error, r=0.71). Sensitivity tests are conducted to investigate the influence of meteorological parameters. The results indicate that the system is sensitive to boundary layer height. When the heights from the numerical weather prediction model are used, only 62.5% of reconstructed emission rates are within a factor two of the actual emissions. This increases to 87.5% when the heights derived from the on-site observations are used. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Tracer experiment data sets for the verification of local and meso-scale atmospheric dispersion models including topographic effects

    International Nuclear Information System (INIS)

    Sartori, E.; Schuler, W.

    1992-01-01

    Software and data for nuclear energy applications are acquired, tested and distributed by several information centres; in particular, relevant computer codes are distributed internationally by the OECD/NEA Data Bank (France) and by ESTSC and EPIC/RSIC (United States). This activity is coordinated among the centres and is extended outside the OECD area through an arrangement with the IAEA. This article proposes more specifically a scheme for acquiring, storing and distributing atmospheric tracer experiment data (ATE) required for verification of atmospheric dispersion models especially the most advanced ones including topographic effects and specific to the local and meso-scale. These well documented data sets will form a valuable complement to the set of atmospheric dispersion computer codes distributed internationally. Modellers will be able to gain confidence in the predictive power of their models or to verify their modelling skills. (au)

  14. Atmospheric Transport Modeling with 3D Lagrangian Dispersion Codes Compared with SF6 Tracer Experiments at Regional Scale

    Directory of Open Access Journals (Sweden)

    François Van Dorpe

    2007-01-01

    Full Text Available The results of four gas tracer experiments of atmospheric dispersion on a regional scale are used for the benchmarking of two atmospheric dispersion modeling codes, MINERVE-SPRAY (CEA, and NOSTRADAMUS (IBRAE. The main topic of this comparison is to estimate the Lagrangian code capability to predict the radionuclide atmospheric transfer on a large field, in the case of risk assessment of nuclear power plant for example. For the four experiments, the results of calculations show a rather good agreement between the two codes, and the order of magnitude of the concentrations measured on the soil is predicted. Simulation is best for sampling points located ten kilometers from the source, while we note a divergence for more distant points results (difference in concentrations by a factor 2 to 5. This divergence may be explained by the fact that, for these four experiments, only one weather station (near the point source was used on a field of 10 000 km2, generating the simulation of a uniform wind field throughout the calculation domain.

  15. The European tracer experiment ETEX: a real-time long range atmospheric dispersion model exercise in different weather conditions

    International Nuclear Information System (INIS)

    Graziani, G.; )

    1998-01-01

    Two long-range tracer experiments were conducted. An inert, non-depositing tracer was being released at Rennes in France for 12 hours. The 168 sampling ground stations were run by the National Meteorological Services. Twenty-four institutions took part in the real-time forecasting of the cloud evolution using 28 long-range dispersion models. The horizontal projection of the cloud evolution over Europe was combined with real-time aerial chemical analysis. The results of the comparison indicate that a limited group of models (7-8) were capable of obtaining a good reproduction of the cloud movement throughout Europe for the first release. Large differences were, however, found in the predicted tracer concentration at a particular location. For the second release, there were large differences between the measured and calculated cloud, particularly after a front passage, which indicates that some efforts have still to be spent before consensus on the model reliability is achieved. (P.A.)

  16. Methods for conduct of atmospheric tracer studies at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Stone, D J.M.; Pascoe, J H [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Division

    2000-07-01

    A perfluorocarbon atmospheric tracer system has been developed to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. This report discusses the tracer release, sampling and analysis methods.

  17. Reducing errors in aircraft atmospheric inversion estimates of point-source emissions: the Aliso Canyon natural gas leak as a natural tracer experiment

    Science.gov (United States)

    Gourdji, S. M.; Yadav, V.; Karion, A.; Mueller, K. L.; Conley, S.; Ryerson, T.; Nehrkorn, T.; Kort, E. A.

    2018-04-01

    Urban greenhouse gas (GHG) flux estimation with atmospheric measurements and modeling, i.e. the ‘top-down’ approach, can potentially support GHG emission reduction policies by assessing trends in surface fluxes and detecting anomalies from bottom-up inventories. Aircraft-collected GHG observations also have the potential to help quantify point-source emissions that may not be adequately sampled by fixed surface tower-based atmospheric observing systems. Here, we estimate CH4 emissions from a known point source, the Aliso Canyon natural gas leak in Los Angeles, CA from October 2015–February 2016, using atmospheric inverse models with airborne CH4 observations from twelve flights ≈4 km downwind of the leak and surface sensitivities from a mesoscale atmospheric transport model. This leak event has been well-quantified previously using various methods by the California Air Resources Board, thereby providing high confidence in the mass-balance leak rate estimates of (Conley et al 2016), used here for comparison to inversion results. Inversions with an optimal setup are shown to provide estimates of the leak magnitude, on average, within a third of the mass balance values, with remaining errors in estimated leak rates predominantly explained by modeled wind speed errors of up to 10 m s‑1, quantified by comparing airborne meteorological observations with modeled values along the flight track. An inversion setup using scaled observational wind speed errors in the model-data mismatch covariance matrix is shown to significantly reduce the influence of transport model errors on spatial patterns and estimated leak rates from the inversions. In sum, this study takes advantage of a natural tracer release experiment (i.e. the Aliso Canyon natural gas leak) to identify effective approaches for reducing the influence of transport model error on atmospheric inversions of point-source emissions, while suggesting future potential for integrating surface tower and

  18. Proceedings of the atmospheric tracers and tracer application workshop

    International Nuclear Information System (INIS)

    Barr, S.; Gedayloo, T.

    1979-12-01

    In addition to presentations by participating members a general discussion was held in order to summarize and outline the goals and objectives of the workshop. A number of new low level background tracers such as heavy methanes, perfluorocarbons, multiply labeled isotopes such as 13 C 18 O 2 , helium 3, in addition to sample collection techniques and analytical methods for various tracers were discussed. This report is a summary of discussions and papers presented at this workshop

  19. CityFlux perfluorocarbon tracer experiments

    Directory of Open Access Journals (Sweden)

    F. K. Petersson

    2010-07-01

    Full Text Available In June 2006, two perfluorocarbon tracer experiments were conducted in central Manchester UK as part of the CityFlux campaign. The main aim was to investigate vertical dispersion in an urban area during convective conditions, but dispersion mechanisms within the street network were also studied. Paired receptors were used in most cases where one receptor was located at ground level and one at roof level. One receptor was located on the roof of Portland Tower which is an 80 m high building in central Manchester. Source receptor distances in the two experiments varied between 120 and 600 m.

    The results reveal that maximum concentration was sometimes found at roof level rather than at ground level implying the effectiveness of convective forces on dispersion. The degree of vertical dispersion was found to be dependent on source receptor distance as well as on building height in proximity to the release site.

    Evidence of flow channelling in a street canyon was also found. Both a Gaussian profile and a street network model were applied and the results show that the urban topography may lead to highly effective flow channelling which therefore may be a very important dispersion mechanism should the right meteorological conditions prevail.

    The experimental results from this campaign have also been compared with a simple urban dispersion model that was developed during the DAPPLE framework and show good agreement with this.

    The results presented here are some of the first published regarding vertical dispersion. More tracer experiments are needed in order to further characterise vertical concentration profiles and their dependence on, for instance, atmospheric stability. The impact of urban topography on pollutant dispersion is important to focus on in future tracer experiments in order to improve performance of models as well as for our understanding of the relationship between air quality and public health.

  20. CityFlux perfluorocarbon tracer experiments

    Science.gov (United States)

    Petersson, F. K.; Martin, D.; White, I. R.; Henshaw, S. J.; Nickless, G.; Longley, I.; Percival, C. J.; Gallagher, M.; Shallcross, D. E.

    2010-07-01

    In June 2006, two perfluorocarbon tracer experiments were conducted in central Manchester UK as part of the CityFlux campaign. The main aim was to investigate vertical dispersion in an urban area during convective conditions, but dispersion mechanisms within the street network were also studied. Paired receptors were used in most cases where one receptor was located at ground level and one at roof level. One receptor was located on the roof of Portland Tower which is an 80 m high building in central Manchester. Source receptor distances in the two experiments varied between 120 and 600 m. The results reveal that maximum concentration was sometimes found at roof level rather than at ground level implying the effectiveness of convective forces on dispersion. The degree of vertical dispersion was found to be dependent on source receptor distance as well as on building height in proximity to the release site. Evidence of flow channelling in a street canyon was also found. Both a Gaussian profile and a street network model were applied and the results show that the urban topography may lead to highly effective flow channelling which therefore may be a very important dispersion mechanism should the right meteorological conditions prevail. The experimental results from this campaign have also been compared with a simple urban dispersion model that was developed during the DAPPLE framework and show good agreement with this. The results presented here are some of the first published regarding vertical dispersion. More tracer experiments are needed in order to further characterise vertical concentration profiles and their dependence on, for instance, atmospheric stability. The impact of urban topography on pollutant dispersion is important to focus on in future tracer experiments in order to improve performance of models as well as for our understanding of the relationship between air quality and public health.

  1. The European Tracer Experiment - experimental results and database

    International Nuclear Information System (INIS)

    Nodop, K.; Connolly, R.; Girardi, F.

    1997-01-01

    As part of the European Tracer Experiment (ETEX) two successful atmospheric experiments were carried out in October and November, 1994. Perfluorocarbon (PFC) tracers were released into the atmosphere in Monterfil, Brittany, and air samples were taken at 168 stations in 17 European countries for 72 hours after the release. Upper air tracer measurements were made from three aircraft. During the first experiment a westerly air flow transported the tracer plume north-eastwards across Europe. During the second release the flow was eastwards. The results from the ground sampling network allowed the determination of the cloud evolution as far as Sweden, Poland and Bulgaria. Typical background concentrations of the tracer used are around 5 to 7 fl/l in ambient air. Concentrations in the plume ranged from 10 to above 200 fl/l. The tracer release characteristics, the tracer concentrations at the ground and in upper air, the routine and additional meteorological observations at the ground level and in upper air, trajectories derived from constant-level balloons and the meteorological input fields for long-range transport (LRT) models are assembled in the ETEX database. The ETEX database is accessible via the Internet

  2. Tracer dispersion - experiment and CFD

    International Nuclear Information System (INIS)

    Zitny, R.

    2004-01-01

    Description of tracer distribution by means of dispersion models is a method successfully used in process engineering for fifty years. Application of dispersion models in reactor engineering for characterization of flows in column apparatus, heat exchangers, etc. is summarized and experimental tracer techniques as well as CFD methods for dispersion coefficients evaluation are discussed. Possible extensions of thermal axial dispersion model (ADM) and a core-wall ADM model suitable for description of tracer dispersion in laminar flows are suggested as well as CFD implementation as 1D finite elements. (author)

  3. Atmospheric Gas Tracers in Groundwater: Theory, Sampling. Measurement and Interpretation

    International Nuclear Information System (INIS)

    Bayari, C.S.

    2002-01-01

    Some of the atmospheric gasses posses features that are sought in an environmental tracer of hydrogeologic interest. Among these, chlorofluorocarbons, sulfur hegzafluoride, carbon tetrachloride, methyl chloroform, krypton-85 etc. have found increasing use in groundwater age dating studies during the last ten years. This paper explains the theory of their use as tracer and discusses the major concerns as related to their sampling and analyses. Factors affecting their applicability and the approach to interpret tracer gas data is briefly outlined

  4. ATTILA - Atmospheric Tracer Transport In a Langrangian Model

    Energy Technology Data Exchange (ETDEWEB)

    Reithmeier, C.; Sausen, R.

    2000-07-01

    The Lagrangian model ATTILA (atmospheric tracer transport in a Lagrangian model) has been developed to treat the global-scale transport of passive trace species in the atmosphere within the framework of a general circulation model (GCM). ATTILA runs online within the GCM ECHAM4 and uses the GCM produced wind field to advect the centrois of 80.000 to 180.000 constant mass air parcels into which the model atmosphere is divided. Each trace constituent is thereby represented by a mass mixing ratio in each parcel. ATTILA contains state-of-the-art parameterizations of convection, turbulent boundary layer mixing, and interparcel transport and provides an algorithm to map the tracer concentrations from the trajectories to the ECHAM model grid. We use two experiments to evaluate the transport characteristics of ATTILA against observations and the standard semiLagrangian transport scheme of ECHAM. In the first experiment we simulate the distribution of the short-lived tracer Radon ({sup 222}Rn) in order to examine fast vertical transport over continents, and long-range transport from the continents to remote areas. In the second experiment, we simulate the distribution of radiocarbon ({sup 14}C) that was injected into the northern stratosphere during the nuclear weapon tests in the early 60ties, in order to examine upper tropospheric and stratospheric transport characteristics. ATTILA compares well to the observations and in many respects to the semiLagrangian scheme. However, contrary to the semiLagrangian scheme, ATTILA shows a greatly reduced meridional transport in the upper troposphere and lower stratosphere, and a reduced downward flux from the stratosphere to the troposphere, especially in midlatitudes. Since both transport schemes use the same model meteorology, we conclude that the often cited enhanced meridional transport and overestimated downward flux in ECHAM as described above is rather due to the numerical properties of the semiLagrangian scheme than due to an

  5. MESYST, Simulation of 3-D Tracer Dispersion in Atmosphere

    International Nuclear Information System (INIS)

    Mastrangelo, V.; Mehilli, I.

    2000-01-01

    1 - Description of program or function: Mesyst code is used for the simulation of 3D tracer dispersion in atmosphere. Three packages are part of this system: Cre-topo: prepares the terrain data for the Mesyst. Noabl: code calculates three- dimensional free divergence wind fields over complex terrain. Pas: Computing of tracer concentrations and depositions on a given domain. 2 - Method of solution: NOABL - Line Over Relaxation + Special adaptation of Gauss procedure. PAS - Monte Carlo Method. 3 - Restrictions on the complexity of the problem: Computations: Mesh size: variable from some meters to some hundreds meters Mesh number: variable depending on available real data (some hundreds points on each directions)

  6. Field studies of transport and dispersion of atmospheric tracers in nocturnal drainage flows

    Science.gov (United States)

    Paul H. Gudiksen; Gilbert J. Ferber; Malcolm M. Fowler; Wynn L. Eberhard; Michael A. Fosberg; William R. Knuth

    1984-01-01

    A series of tracer experiments were carried out as part of the Atmospheric Studies in Complex Terrain (ASCOT) program to evaluate pollutant transport and dispersion characteristics of nocturnal drainage flows within a valley in northern California. The results indicate that the degree of interaction of the drainage flows with the larger scale regional flows are...

  7. A description of the atmospheric tracer technology used at the J.R.C.-Ispra

    International Nuclear Information System (INIS)

    Gaglione, P.

    1988-01-01

    Atmospheric tracers are a versatile tool that can be used in conjunction with basic meteorological investigations and models to gain a better understanding of the dynamical behaviour of atmospheric pollutants on both the local and regional scales. The tracer activity was initiated at Ispra about ten years ago, with the aim of providing an experimental support to the research activity carried out in the field of air pollution modeling. At the time the area of interest was mainly related to the atmospheric dispersion on a local scale of pollutants released from stacks of power stations, therefore a technique using SF 6 as a tracer was implemented. In the last few years some efforts have been devoted also to the determination of the atmospheric dispersion parameters in the mesoscale and in the regional scale. Due to the limitations in the use of SF 6 over these distances, a new technique utilizing perfluorocarbons (C 7 F 14 and C 8 F 16 ) as tracers has been implemented and positively tested in the field, even though limited until now to a few short range experiments. The purpose of this presentation is to describe the tracer technology developments at the J.R.C.-Ispra including the main results obtained in different field studies

  8. Tracer water transport and subgrid precipitation variation within atmospheric general circulation models

    Science.gov (United States)

    Koster, Randal D.; Eagleson, Peter S.; Broecker, Wallace S.

    1988-03-01

    A capability is developed for monitoring tracer water movement in the three-dimensional Goddard Institute for Space Science Atmospheric General Circulation Model (GCM). A typical experiment with the tracer water model follows water evaporating from selected grid squares and determines where this water first returns to the Earth's surface as precipitation or condensate, thereby providing information on the lateral scales of hydrological transport in the GCM. Through a comparison of model results with observations in nature, inferences can be drawn concerning real world water transport. Tests of the tracer water model include a comparison of simulated and observed vertically-integrated vapor flux fields and simulations of atomic tritium transport from the stratosphere to the oceans. The inter-annual variability of the tracer water model results is also examined.

  9. Tracer water transport and subgrid precipitation variation within atmospheric general circulation models

    Science.gov (United States)

    Koster, Randal D.; Eagleson, Peter S.; Broecker, Wallace S.

    1988-01-01

    A capability is developed for monitoring tracer water movement in the three-dimensional Goddard Institute for Space Science Atmospheric General Circulation Model (GCM). A typical experiment with the tracer water model follows water evaporating from selected grid squares and determines where this water first returns to the Earth's surface as precipitation or condensate, thereby providing information on the lateral scales of hydrological transport in the GCM. Through a comparison of model results with observations in nature, inferences can be drawn concerning real world water transport. Tests of the tracer water model include a comparison of simulated and observed vertically-integrated vapor flux fields and simulations of atomic tritium transport from the stratosphere to the oceans. The inter-annual variability of the tracer water model results is also examined.

  10. Data of atmospheric diffusion experiments (Tsukuba, 1989)

    International Nuclear Information System (INIS)

    Hayashi, Takashi; Chino, Masamichi; Yamazawa, Hiromi; Moriuchi, Shigeru; Ishikawa, Hirohiko; Adachi, Takashi; Kojima, Hiromi

    1999-08-01

    The data were obtained in the atmospheric diffusion experiments in the Tsukuba area, 1989 which were a part of the Experiment to Demonstrate the Propriety of Atmospheric Dispersion Evaluation Method for Safety Analysis, entrusted with the Science and Technology Agency. The experiments were conducted by JAERI in cooperation with the Japan Weather Association. The report contains tracer concentration data of surface sampling points and meteorological data. (author)

  11. Modelling and tracer studies of atmospheric dispersion and deposition in regions of complex topography

    International Nuclear Information System (INIS)

    Norden, C.E.

    1981-11-01

    An indium tracer aerosol generating apparatus based on an alcohol/oxygen burner, and an analytical procedure by which filter samples containing tracer material could be analysed quantitatively by means of neutron activation analysis, were developed for use in atmospheric dispersion and deposition studies. A number of series of atmospheric dispersion experiments were conducted in the Richards Bay and Koeberg- Cape Town areas. The results are given, comparing the airbone tracer concentrations measured at ground level with values predicted by means of a numerical model, utilising two to three schemes, varying in sophistication, for calculating the dispersion coefficients. Recommendations are given regarding a dispersion model and dispersion coefficients for regular use in the Koeberg area, and ways for estimating plume trajectories

  12. Heavy methanes (mass-20 and -21) as atmospheric tracers. A new research initiatives project

    International Nuclear Information System (INIS)

    Guthals, P.R.; Fowler, M.M.

    1978-07-01

    Products from the stable isotope production project (ICONS) at the Los Alamos Scientific Laboratory (LASL) have had applications in a number of practical problems. Fully deuterated methanes, using 12 C and 13 C (mass-20 and -21, respectively), are detectable in the atmosphere at very low concentrations. The detection limits are due to an almost zero background and a distinct mass-spectrometric line. These properties, coupled with long lifetimes in the atmosphere, make the heavy methanes strong candidates for tracers of atmospheric transport and turbulence on regional to global scales. Three field tests have been conducted to assess the feasibility and to demonstrate the desirable properties of heavy methanes as atmospheric tracers. In the first test in May 1974, heavy methane released at the Idaho National Engineering Laboratory (INEL) was sampled and detected in several midwestern cities up to 2500 km downstream. These results agree with trajectories estimated from observed meteorological data. A second experiment, conducted in December 1975 at the Savannah River Plant, compared two heavy methanes with SF 6 and 85 Kr over a transport distance of 100 km. Increased detail in meteorological support data and ground-level sampling offered options of data interpretation unavailable in the first test. Qualitative patterns of tracer concentrations show good agreement among the four tracers and are verified by the meteorological inputs. The third experiment, performed in April 1977 at INEL, built on the experience of the previous two. Detailed ground-level sampling arrays at 3, 50, and 90 km from the release point were supplemented by aircraft and a crude sampling line across the Continental Divide at 300-km distance. Two new perfluorocarbon tracers were included for comparison

  13. Tracer migration experiments in the Stripa mine 1980-1991

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.

    1992-05-01

    During more than 10 years, tracer experiments have been performed in the Stripa mine as part of the Stripa project to investigate the properties of both 'average' fractured rock and fracture zones. Experiments have been performed that have ranged from a few decimeters, to examine the diffusion into the rock matrix, up to tracer migration to a drift more than 50 meters from the injection point. This report compiles the results and experience that have been gained from all these tracer experiments. The experiments that are described in this report are: * The in-situ diffusion experiment where simultaneous flow and diffusion of tracers in undisturbed rock were studied over more than 3 years to validate diffusivities obtained under laboratory conditions. * Migration in a single fracture where water flow distribution and tracer transport were studied using both conservative and sorbing tracers over migration distances up to 10 meters. * The 3-D migration experiment where water inflow and tracer transport to a drift covered with 350 plastic sheet were investigated to get information on flow porosity, dispersion and channeling. The transport distances were between 10 and 56 meters from the injection points to the drift. * The channeling experiments in which the aim was to examine the channeling properties of single fractures in detail. Pressure pulse tests and tracer experiments were performed over a distances of 2 meters. * The tracer migration experiment in the validation drift where the tracer were injected mainly in a fracture zone and the collection was inside both a drift covered with plastic sheets similar to in the 3-D experiment as well as in a borehole. The distances between injection and sampling location were between 10 and 25 meters. (57 refs.) (au)

  14. A tracer investigation of the atmospheric dispersion in the Dyrnaes Valley, Greenland

    International Nuclear Information System (INIS)

    Gryning, S.-E.; Lyck, E.

    1983-02-01

    Mining at Kvanefjeld, Greenland, will result in releases of air pollution gases. In order to measure the dilution of these gases tracer experiments were carried out in July-August 1981. Results from these experiments are described. The Kvanefjeld constitutes the northwestern side of a valley. The tracer was released at the Kvanefjeld during the night and sampled in the valley. The measured tracer concentrations were compared with those calculated by use of a conventional model of the dispersion of plumes. The dilution of the tracer was found to correspond to the dilution at ground level of a plume from a stack of 100-200 m height in atmospheric neutral conditions (wind speed 5 m/s). General aspects of the flow-field in the valley are discussed. It was observed that the flow direction in the valley shifts between downvalley and upvalley with a period of approximately 1 hour. It is suggested that this behaviour is caused by the interplay of a drainage flow and a sea-breeze. (author)

  15. 3-D migration experiment - report 2: Instrumentation and tracers

    International Nuclear Information System (INIS)

    Abelin, H.; Birgersson, L.; Gidlund, J.

    1987-11-01

    This report is one of the four reports describing the Stripa 3D experiment where water and tracer flow has been monitored in a specially excavated drift in the Stripa mine. The experiment was performed in a specially excavated drift at the 360 m level in granite. The whole ceiling and upper part of the walls were covered with more than 350 individual plastic sheets where the water flow into the drift could be collected. 11 different tracers were injected at distances between 11 and 50 m from the ceiling of the drift. The flow rate and tracer monitoring was kept up for more than two years. The tracer breakthrough curves and flow rate distributions were used to study the flow paths, velocities, hydraulic conductivities, dispersivities and channeling effects in the rock. The report describes the instrumentation developed and used as well as the tracers that were tested and used in the experiment. (orig.)

  16. Use of labeled compounds in tracer experiments

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The use of radiotracers in research has become common. This chapter looks at some of the underlying assumptions and advantages of labeled compounds: advantages of radiotracers; availability of suitable tracers and labeled compounds; purity of labeled compounds; autoradiolysis; storage of labeled compounds; detection systems for chromatography and electrophoretic methods. 14 refs., 2 figs

  17. Small molecules as tracers in atmospheric secondary organic aerosol

    Science.gov (United States)

    Yu, Ge

    Secondary organic aerosol (SOA), formed from in-air oxidation of volatile organic compounds, greatly affects human health and climate. Although substantial research has been devoted to SOA formation and evolution, the modeled and lab-generated SOA are still low in mass and degree of oxidation compared to ambient measurements. In order to compensate for these discrepancies, the aqueous processing pathway has been brought to attention. The atmospheric waters serve as aqueous reaction media for dissolved organics to undergo further oxidation, oligomerization, or other functionalization reactions, which decreases the vapor pressure while increasing the oxidation state of carbon atoms. Field evidence for aqueous processing requires the identification of tracer products such as organosulfates. We synthesized the standards for two organosulfates, glycolic acid sulfate and lactic acid sulfate, in order to measure their aerosol-state concentration from five distinct locations via filter samples. The water-extracted filter samples were analyzed by LC-MS. Lactic acid sulfate and glycolic acid sulfate were detected in urban locations in the United States, Mexico City, and Pakistan with varied concentrations, indicating their potential as tracers. We studied the aqueous processing reaction between glyoxal and nitrogen-containing species such as ammonium and amines exclusively by NMR spectrometry. The reaction products formic acid and several imidazoles along with the quantified kinetics were reported. The brown carbon generated from these reactions were quantified optically by UV-Vis spectroscopy. The organic-phase reaction between oxygen molecule and alkenes photosensitized by alpha-dicarbonyls were studied in the same manner. We observed the fast kinetics transferring alkenes to epoxides under simulated sunlight. Statistical estimations indicate a very effective conversion of aerosol-phase alkenes to epoxides, potentially forming organosulfates in a deliquescence event and

  18. Development and Validation of Water Vapor Tracers as Diagnostics for the Atmospheric Hydrologic Cycle

    Science.gov (United States)

    Bosilovich, Michael G.; Schubert, Siegfried D.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Understanding of the local and remote sources of water vapor can be a valuable diagnostic in understanding the regional atmospheric hydrologic cycle. In the present study, we have implemented passive tracers as prognostic variables to follow water vapor evaporated in predetermined regions until the water tracer precipitates. The formulation of the sources and sinks of tracer water is generally proportional to the prognostic water vapor variable. Because all water has been accounted for in tracers, the water vapor variable provides the validation of the tracer water and the formulation of the sources and sinks. The tracers have been implemented in a GEOS General Circulation Model (GCM) simulation consisting of several summer periods to determine the source regions of precipitation for the United States and India. The recycling of water and interannual variability of the sources of water will be examined. Potential uses in GCM sensitivity studies, predictability studies and data assimilation will be discussed.

  19. Our experience of blood flow measurements using radioactive tracers

    International Nuclear Information System (INIS)

    Danet, Bernard.

    1974-01-01

    A critical study of blood flow measuring methods is proposed. After a review of the various diffusible and non-diffusible radioactive tracers and the corresponding detector systems, the principles which allow to measure blood flow from the data so obtained, are studied. There is a different principle of flow measurement for each type of tracer. The theory of flow measurement using non-diffusible tracers (human serum albumin labelled with 131 I or sup(99m)Tc, 113 In-labelled siderophiline) and its application to cardiac flow measurement are described first. Then the theory of flow measurement using diffusible tracers ( 133 Xe, 85 Kr) and its application to measurement of blood flow through tissues (muscles and kidney particularly) are described. A personal experience of this various flow measurements is reported. The results obtained, the difficulties encountered and the improvments proposed are developed [fr

  20. Elevated source SF6-tracer dispersion experiments in the Copenhagen area. Preliminary results II

    International Nuclear Information System (INIS)

    Gryning, S.E.; Lyck, E.

    1980-01-01

    The results from 10 experiments, performed in neutral to unstable meteorological conditions, are reported from an ongoing series of elevated-source, urban-scale tracer dispersion experiments in the Copenhagen area. The tracer is released at a height of 115 m from the TV-tower in GLADSAXE, a suburb of Copenhagen, with tracer sampling units positioned at ground-level in 1 to 3 crosswind series, 2 to 6 km downwind of the tower. The lateral dispersion parameter, sigma(y), was estimated from the measured tracer concentration distribution and compared with values of sigma(y), computed by 1) methods based on wind variance measured during the experiments and 2) methods based on a stability classification of the atmospheric conditions. The wind-variance based methods proved superior in predicting the variation of sigma(y) compared with the stability based methods. Moreover, some of the former methods produced significantly biased estimates of sigma(y). The measured tracer concentration distributions were also crosswind integrated, chi(CWI). Estimates of chi(CWI) were computed using sigma (z) -values derived from the aforementioned computations assuming a Gaussian-type vertical tracer concentration distribution. A comparison is measured and calculated values of chi(CWI) showed no significant differences in the ability of the methods to predict the variation of chi(CWI). Only one method, the EPA, came out with a mean fractional error outside the range +-20% which constitutes the uncertainty in the absolute tracer concentration associated with the calibration of the gas chromatograph for tracer analysis

  1. Data volume of atmospheric tracer studies at Lucas Heights, NSW, Australia -1996-1997

    International Nuclear Information System (INIS)

    Clark, G.H.; Stone, D.J.M.; Pascoe, J.H.

    2000-01-01

    A perfluorocarbon atmospheric tracer system has been used to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. Tracers have been released from two locations: a laboratory vent near the ridge of the Woronora river valley and from the HIFAR research reactor ventilation system. Most studies have been conducted during the early to late morning periods when valley influences might be expected on dispersion of the tracer plume. This report summarises the meteorological and tracer air concentration data and makes comparisons with estimates from a simple gaussian dispersion model. It is intended that the data will also be used for evaluation of more elaborate wind field and atmospheric models

  2. Live controls for radioisotope tracer food chain experiments using meiofauna

    International Nuclear Information System (INIS)

    Montagna, P.A.

    1983-01-01

    Formalin poisoned samples are inadequate for measuring the amount of label to be subtracted as control values for certain food chain studies that employ radioactive tracers. In some studies, tracer is added just before incubation to label ''food'' during the feeding study. Commonly, parallel, poisoned incubations are used to distinguish between biotic and abiotic label incorporation. But, a poisoned control does not account for label that could enter a consumer via active transport, epicuticular microfloral uptake, or grazing on labeled, non-food particles. Experiments were performed to test if label uptake is greater in live non-grazing than dead organisms. Marine benthic meiofauna incoporate from 3 to 133 times more tracer when they are alive and not grazing than when they are formalin killed. These results suggest that control experiments with live animals be performed to measure all processes by which label can enter consumers in food chain experiments. (orig.)

  3. Atmospheric tracer tests and assessment of a potential accident at the National Medical Cyclotron, Camperdown, NSW, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G H; Bartsch, F J.K.; Stone, D J.M.

    1994-08-01

    In order to assess the impact of a potential atmospheric release of radionuclides from the National Medical Cyclotron facility, in Camperdown, an atmospheric tracer release, sampling and analysis system using SF{sub 6} was developed. During eight experiments conducted in a variety of meteorological conditions, ten samplers were located in the vicinity of the Cyclotron building and other nearby buildings on the rapid downward movement of the tracer gas plume. The atmospheric dilution factors which lead to the highest observed air concentrations were then applied to the releases of I{sup 123} and Xe{sup 123} from a potential accident scenario in order to assess the impact on nearby receptors. Even given the conservative assumptions about the release of I{sup 123}, the estimated radiation doses were at least an order of magnitude below the international standards for doses to member of the public. 27 refs., 8 tabs., 5 figs.

  4. Atmospheric tracer tests and assessment of a potential accident at the National Medical Cyclotron, Camperdown, NSW, Australia

    International Nuclear Information System (INIS)

    Clark, G.H.; Bartsch, F.J.K.; Stone, D.J.M.

    1994-08-01

    In order to assess the impact of a potential atmospheric release of radionuclides from the National Medical Cyclotron facility, in Camperdown, an atmospheric tracer release, sampling and analysis system using SF 6 was developed. During eight experiments conducted in a variety of meteorological conditions, ten samplers were located in the vicinity of the Cyclotron building and other nearby buildings on the rapid downward movement of the tracer gas plume. The atmospheric dilution factors which lead to the highest observed air concentrations were then applied to the releases of I 123 and Xe 123 from a potential accident scenario in order to assess the impact on nearby receptors. Even given the conservative assumptions about the release of I 123 , the estimated radiation doses were at least an order of magnitude below the international standards for doses to member of the public. 27 refs., 8 tabs., 5 figs

  5. Inert tracer wind resuspension as a function of wind speed, atmospheric stability, and initial tracer particle size

    International Nuclear Information System (INIS)

    Sehmel, G.A.; Lloyd, F.D.

    1979-01-01

    Wind-caused resuspension rates are being determined in three different, long-term, inert-tracer field experiments. Chemical results were recently received from an accumulated backlog of air filter samples. Resuspension rates are yet to be calculated from these data

  6. Inverse modelling of atmospheric tracers: non-Gaussian methods and second-order sensitivity analysis

    Directory of Open Access Journals (Sweden)

    M. Bocquet

    2008-02-01

    Full Text Available For a start, recent techniques devoted to the reconstruction of sources of an atmospheric tracer at continental scale are introduced. A first method is based on the principle of maximum entropy on the mean and is briefly reviewed here. A second approach, which has not been applied in this field yet, is based on an exact Bayesian approach, through a maximum a posteriori estimator. The methods share common grounds, and both perform equally well in practice. When specific prior hypotheses on the sources are taken into account such as positivity, or boundedness, both methods lead to purposefully devised cost-functions. These cost-functions are not necessarily quadratic because the underlying assumptions are not Gaussian. As a consequence, several mathematical tools developed in data assimilation on the basis of quadratic cost-functions in order to establish a posteriori analysis, need to be extended to this non-Gaussian framework. Concomitantly, the second-order sensitivity analysis needs to be adapted, as well as the computations of the averaging kernels of the source and the errors obtained in the reconstruction. All of these developments are applied to a real case of tracer dispersion: the European Tracer Experiment [ETEX]. Comparisons are made between a least squares cost function (similar to the so-called 4D-Var approach and a cost-function which is not based on Gaussian hypotheses. Besides, the information content of the observations which is used in the reconstruction is computed and studied on the application case. A connection with the degrees of freedom for signal is also established. As a by-product of these methodological developments, conclusions are drawn on the information content of the ETEX dataset as seen from the inverse modelling point of view.

  7. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Directory of Open Access Journals (Sweden)

    S. Ars

    2017-12-01

    Full Text Available This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping

  8. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Science.gov (United States)

    Ars, Sébastien; Broquet, Grégoire; Yver Kwok, Camille; Roustan, Yelva; Wu, Lin; Arzoumanian, Emmanuel; Bousquet, Philippe

    2017-12-01

    This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances

  9. Air pollution tracer studies in the lower atmosphere (citations from the NTIS data base). Report for 1964-Jan 80

    International Nuclear Information System (INIS)

    Cavagnaro, D.M.

    1980-02-01

    The cited reports cover research on the use of tracers to study lower atmospheric air pollution movements. The tracer used include sulfur hexafluoride, krypton 85, carbon 14, and other radioactive isotopes. The studies cite the results and techniques used, tracer movement from nuclear power plants, industrial stacks, urban areas, and the detectors used in their measurement

  10. Tracer chemistry in the laboratory and the atmosphere

    International Nuclear Information System (INIS)

    Rowland, F.S.

    1994-01-01

    The steady bombardment of the Earth's atmosphere by cosmic radiation induces numerous radioactive species in the atmosphere of which the best known are 14 C and T. Others of interest include 7 Be, 10 Be, and several isotopes of chlorine. The eventual formation of 14 CO 2 and its subsequent significance for archaeological dating were brilliantly established by Willard Libby in the 1940s. However, the initial reactions of nascent 14 C in a mixture of N 2 and O 2 produce 14 CO, as shown first in the lab. and then in the atmosphere. Because cosmic ray production rates are essentially constant in a given location, the observed concentration of 14 CO provides an excellent tool for studying the removal process, oxidation by HO to form 14 CO 2 . Because 14 CO 2 becomes incorporated into all living biological species, other molecules become labeled with 14 C as well, including 14 CH 4 . Measurement of the 14 C radioactivity of such molecules in the atmosphere allows apportionment of sources between biological and fossil fuel origins. Tritium atoms are also formed by cosmic radiation, and can subsequently be incorporated into the chemical forms HT and HTO. Although most T atoms from cosmic radiation are found as HTO, the much higher specific radioactivity of HT provides interesting insights into atmospheric processes. Lab. studies furnish important clues for understanding the atmospheric routes. The differences in radioactive half-lives cause the terrestrial locations of cosmic ray induced 7 Be and 10 Be to be primarily the atmosphere and the oceans, respectively. In a comparable manner, the chemistry of atmospheric radiochlorine divides between the very long-lived 36 Cl and three isotopes with half-lives less than an hour, 34m Cl, 38 Cl and 39 Cl

  11. The field tracer test study of atmospheric dispersion in Fujian Huian Nuclear Power Plant site

    International Nuclear Information System (INIS)

    Hu Erbang; Xin Cuntian; Yan Jiangyu; Ren Zhiqiang; Xuan Yiren; Jia Peirong

    2003-01-01

    The SF 6 tracer tests and its main results completed in site of Fujian Huian Nuclear Power Plant during summer, 2002, are described. A total of 15 times of SF 6 tracer tests were done in the July, in which the time of atmospheric stability B, C, D, E is respectively 3, 2, 9, 1 based on ΔT-U method and the time of B, D, E is respectively 1, 11, 3 based on ΔT method. About 50 samples were collected in each SF 6 tracer tests, the maximum of sample distance from the tower in which the SF 6 tracer was released is about 15 km. The values of p y , p z , q y , q z in the formula of diffusion parameters is determined. Finally the above diffusion parameters are compared with P-G curve, Briggs diffusion parameters and those obtained from turbulence observation and wind tunnel simulation test done in the past time. (authors)

  12. INTRAVAL Finnsjoen Test - modelling results for some tracer experiments

    International Nuclear Information System (INIS)

    Jakob, A.; Hadermann, J.

    1994-09-01

    This report presents the results within Phase II of the INTRAVAL study. Migration experiments performed at the Finnsjoen test site were investigated. The study was done to gain an improved understanding of not only the mechanisms of tracer transport, but also the accuracy and limitations of the model used. The model is based on the concept of a dual porosity medium, taking into account one dimensional advection, longitudinal dispersion, sorption onto the fracture surfaces, diffusion into connected pores of the matrix rock, and sorption onto matrix surfaces. The number of independent water carrying zones, represented either as planar fractures or tubelike veins, may be greater than one, and the sorption processes are described either by linear or non-linear Freundlich isotherms assuming instantaneous sorption equilibrium. The diffusion of the tracer out of the water-carrying zones into connected pore space of the adjacent rock is calculated perpendicular to the direction of the advective/dispersive flow. In the analysis, the fluid flow parameters are calibrated by the measured breakthrough curves for the conservative tracer (iodide). Subsequent fits to the experimental data for the two sorbing tracers strontium and cesium then involve element dependent parameters providing information on the sorption processes and on its representation in the model. The methodology of fixing all parameters except those for sorption with breakthrough curves for non-sorbing tracers generally worked well. The investigation clearly demonstrates the necessity of taking into account pump flow rate variations at both boundaries. If this is not done, reliable conclusions on transport mechanisms or geometrical factors can not be achieved. A two flow path model reproduces the measured data much better than a single flow path concept. (author) figs., tabs., 26 refs

  13. Data of long term atmospheric diffusion experiments (Winter, 1992)

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Takashi; Chino, Masamichi; Yamazawa, Hiromi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1998-10-01

    The data were obtained in the long-term atmospheric diffusion experiments in the Tokai area, autumn, 1991 which were a part of the Evaluation Safety Demonstration Experiments of Environmental Radiation entrusted with the Science and Technology Agency. The experiments were conducted by JAERI in cooperation with the Japan Weather Association. The report includes tracer concentration data of surface sampling points and meteorological data. (author)

  14. Tracer experiment by using radioisotope in surface water environment

    International Nuclear Information System (INIS)

    Suh, K.S.; Kim, K.C.; Chun, I.Y.; Jung, S.H.; Lee, C.W.

    2007-01-01

    Complete text of publication follows. 1. Objective An expansion of industrial activities and urbanization result in still increasing amount of pollutants discharged into surface water. Discharged pollutants in surface water have harmful effects on the ecology of a river system and human beings. Pollutants discharged into surface water is transported and dispersed under conditions characteristic to particular natural water receiver. Radiotracer method is a useful tool for monitoring the pollutant dispersion and description of mixing process taking place in natural streams. A tracer experiment using radioisotope was carried out to investigate the characteristics of a pollutant transport and a determination of the diffusion coefficients in a river system. 2. Methods The upper area of the Keum river was selected for the tracer experiment, which is located in a mid west of Korea. The measurements of the velocity and bathymetry before a tracer experiment were performed to select the sampling lines for a detection of the radioisotope. The radioisotope was instantaneously injected into a flow as a point source by an underwater glass-vial crusher. The detection was made with 60 2inch NaI(Tl) scintillation detectors at 3 transverse lines at a downstream position. The multi-channel data acquisition systems were used to collect and process the signals transmitted from the detectors. Two-dimensional numerical models were used to simulate the hydraulic parameters and the concentration distributions of the radioisotope injected into the river. 3. Results and Conclusion The calculated results such as velocity and concentrations were compared with the measured ones. The dispersion characteristics of the radioisotope were analyzed according to a variation of the flow rate, water level and diffusion coefficients. Also, the diffusion coefficients were calculated by using the measured concentrations and the coefficients obtained from the field experiment were compared with the ones

  15. Discrete fracture modelling for the Stripa tracer validation experiment predictions

    International Nuclear Information System (INIS)

    Dershowitz, W.; Wallmann, P.

    1992-02-01

    Groundwater flow and transport through three-dimensional networks of discrete fractures was modeled to predict the recovery of tracer from tracer injection experiments conducted during phase 3 of the Stripa site characterization and validation protect. Predictions were made on the basis of an updated version of the site scale discrete fracture conceptual model used for flow predictions and preliminary transport modelling. In this model, individual fractures were treated as stochastic features described by probability distributions of geometric and hydrologic properties. Fractures were divided into three populations: Fractures in fracture zones near the drift, non-fracture zone fractures within 31 m of the drift, and fractures in fracture zones over 31 meters from the drift axis. Fractures outside fracture zones are not modelled beyond 31 meters from the drift axis. Transport predictions were produced using the FracMan discrete fracture modelling package for each of five tracer experiments. Output was produced in the seven formats specified by the Stripa task force on fracture flow modelling. (au)

  16. Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, Melissa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Heredia, Elizabeth [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cohn, Sebastian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Noris, Federico [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Logue, Jennifer [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-01

    This report documents experiments performed in three homes to assess the methodology used to determine air exchange rates using passive tracer techniques. The experiments used four different tracer gases emitted simultaneously but implemented with different spatial coverage in the home. Two different tracer gas sampling methods were used. The results characterize the factors of the execution and analysis of the passive tracer technique that affect the uncertainty in the calculated air exchange rates. These factors include uncertainties in tracer gas emission rates, differences in measured concentrations for different tracer gases, temporal and spatial variability of the concentrations, the comparison between different gas sampling methods, and the effect of different ventilation conditions.

  17. Inversion of Atmospheric Tracer Measurements, Localization of Sources

    Science.gov (United States)

    Issartel, J.-P.; Cabrit, B.; Hourdin, F.; Idelkadi, A.

    When abnormal concentrations of a pollutant are observed in the atmosphere, the question of its origin arises immediately. The radioactivity from Tchernobyl was de- tected in Sweden before the accident was announced. This situation emphasizes the psychological, political and medical stakes of a rapid identification of sources. In tech- nical terms, most industrial sources can be modeled as a fixed point at ground level with undetermined duration. The classical method of identification involves the cal- culation of a backtrajectory departing from the detector with an upstream integration of the wind field. We were first involved in such questions as we evaluated the ef- ficiency of the international monitoring network planned in the frame of the Com- prehensive Test Ban Treaty. We propose a new approach of backtracking based upon the use of retroplumes associated to available measurements. Firstly the retroplume is related to inverse transport processes, describing quantitatively how the air in a sam- ple originates from regions that are all the more extended and diffuse as we go back far in the past. Secondly it clarifies the sensibility of the measurement with respect to all potential sources. It is therefore calculated by adjoint equations including of course diffusive processes. Thirdly, the statistical interpretation, valid as far as sin- gle particles are concerned, should not be used to investigate the position and date of a macroscopic source. In that case, the retroplume rather induces a straightforward constraint between the intensity of the source and its position. When more than one measurements are available, including zero valued measurements, the source satisfies the same number of linear relations tightly related to the retroplumes. This system of linear relations can be handled through the simplex algorithm in order to make the above intensity-position correlation more restrictive. This method enables to manage in a quantitative manner the

  18. Meteorological conditions at the release site during the two tracer experiments

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.; Schneiter, D.

    1998-01-01

    The state of the boundary layer at the release site during the two tracer experiments is described, based on measurements of atmospheric turbulence carried our by a sonic anemometer, profiles of horizontal and vertical wind by a SODAR as well as frequent radiosonde releases. The boundary layer...... height is derived from radiosoundings, modelled and discussed. The study is meant as background for discussions of the tracer behaviour near the release site, and possible influence of the local meteorology at the release site on the long-range dispersion. The difference in the initial mese...... model development. It is concluded that the micrometeorological measurements are very important as background information for the understanding of plume behaviour on small as well as long scales. (C) 1998 Elsevier Science Ltd. All rights reserved....

  19. Stratospheric temperatures and tracer transport in a nudged 4-year middle atmosphere GCM simulation

    Science.gov (United States)

    van Aalst, M. K.; Lelieveld, J.; Steil, B.; Brühl, C.; Jöckel, P.; Giorgetta, M. A.; Roelofs, G.-J.

    2005-02-01

    We have performed a 4-year simulation with the Middle Atmosphere General Circulation Model MAECHAM5/MESSy, while slightly nudging the model's meteorology in the free troposphere (below 113 hPa) towards ECMWF analyses. We show that the nudging 5 technique, which leaves the middle atmosphere almost entirely free, enables comparisons with synoptic observations. The model successfully reproduces many specific features of the interannual variability, including details of the Antarctic vortex structure. In the Arctic, the model captures general features of the interannual variability, but falls short in reproducing the timing of sudden stratospheric warmings. A 10 detailed comparison of the nudged model simulations with ECMWF data shows that the model simulates realistic stratospheric temperature distributions and variabilities, including the temperature minima in the Antarctic vortex. Some small (a few K) model biases were also identified, including a summer cold bias at both poles, and a general cold bias in the lower stratosphere, most pronounced in midlatitudes. A comparison 15 of tracer distributions with HALOE observations shows that the model successfully reproduces specific aspects of the instantaneous circulation. The main tracer transport deficiencies occur in the polar lowermost stratosphere. These are related to the tropopause altitude as well as the tracer advection scheme and model resolution. The additional nudging of equatorial zonal winds, forcing the quasi-biennial oscillation, sig20 nificantly improves stratospheric temperatures and tracer distributions.

  20. Atmospheric Gas Tracers in Groundwater: Theory, Sampling. Measurement and Interpretation; Yeraltisuyunda Atmosferik Gaz Izleyiciler: Kuram, Oernekleme, Oelcuem ve Yorum

    Energy Technology Data Exchange (ETDEWEB)

    Bayari, C S [Hacettepe University, Ankara(Turkey)

    2002-07-01

    Some of the atmospheric gasses posses features that are sought in an environmental tracer of hydrogeologic interest. Among these, chlorofluorocarbons, sulfur hegzafluoride, carbon tetrachloride, methyl chloroform, krypton-85 etc. have found increasing use in groundwater age dating studies during the last ten years. This paper explains the theory of their use as tracer and discusses the major concerns as related to their sampling and analyses. Factors affecting their applicability and the approach to interpret tracer gas data is briefly outlined.

  1. Double tracer experiments to investigate models for the calculation of gamma doses from a radioactive cloud

    International Nuclear Information System (INIS)

    Nielsen, S.P.; Gryning, S.E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.

    1984-01-01

    The paper presents work from a series of atmospheric dispersion experiments in May 1981 at the Ringhals nuclear power plant in Sweden. The aim of the project was to obtain short-term observations of concentrations and gamma-ray exposures from stack effluents and to compare these results with corresponding values calculated from computer models. Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released from a 110-m stack and detected at ground level downwind at distances of 3-4 km. Calculations were made with two Gaussian plume models: PLUCON developed at Riso National Laboratory and UNIDOSE developed at Studsvik Energiteknik AB. (orig.)

  2. Reconstruction of Atmospheric Tracer Releases with Optimal Resolution Features: Concentration Data Assimilation

    Science.gov (United States)

    Singh, Sarvesh Kumar; Turbelin, Gregory; Issartel, Jean-Pierre; Kumar, Pramod; Feiz, Amir Ali

    2015-04-01

    function which exhibits a priori information about the unknown releases apparent to the monitoring network. The properties of the weight function provide an optimal data resolution and model resolution to the retrieved source estimates. The retrieved source estimates are proved theoretically to be stable against the random measurement errors and their reliability can be interpreted in terms of the distribution of the weight functions. Further, the same framework can be extended for the identification of the point type releases by utilizing the maximum of the retrieved source estimates. The inversion technique has been evaluated with the several diffusion experiments, like, Idaho low wind diffusion experiment (1974), IIT Delhi tracer experiment (1991), European Tracer Experiment (1994), Fusion Field Trials (2007), etc. In case of point release experiments, the source parameters are mostly retrieved close to the true source parameters with least error. Primarily, the proposed technique overcomes two major difficulties incurred in the source reconstruction: (i) The initialization of the source parameters as required by the optimization based techniques. The converged solution depends on their initialization. (ii) The statistical knowledge about the measurement and background errors as required by the Bayesian inference based techniques. These are hypothetically assumed in case of no prior knowledge.

  3. Crustal tracers in the atmosphere and ocean: Relating their concentrations, fluxes, and ages

    Science.gov (United States)

    Han, Qin

    Crustal tracers are important sources of key limiting nutrients (e.g., iron) in remote ocean regions where they have a large impact on global biogeochemical cycles. However, the atmospheric delivery of bio-available iron to oceans via mineral dust aerosol deposition is poorly constrained. This dissertation aims to improve understanding and model representation of oceanic dust deposition and to provide soluble iron flux maps by testing observations of crustal tracer concentrations and solubilities against predictions from two conceptual solubility models. First, we assemble a database of ocean surface dissolved Al and incorporate Al cycling into the global Biogeochemical Elemental Cycling (BEC) model. The observed Al concentrations show clear basin-scale differences that are useful for constraining dust deposition. The dynamic mixed layer depth and Al residence time in the BEC model significantly improve the simulated dissolved Al field. Some of the remaining model-data discrepancies appear related to the neglect of aerosol size, age, and air mass characteristics in estimating tracer solubility. Next, we develop the Mass-Age Tracking method (MAT) to efficiently and accurately estimate the mass-weighted age of tracers. We apply MAT to four sizes of desert dust aerosol and simulate, for the first time, global distributions of aerosol age in the atmosphere and at deposition. These dust size and age distributions at deposition, together with independent information on air mass acidity, allow us to test two simple yet plausible models for predicting the dissolution of mineral dust iron and aluminum during atmospheric transport. These models represent aerosol solubility as controlled (1) by a diffusive process leaching nutrients from the dust into equilibrium with the liquid water coating or (2) by a process that continually dissolves nutrients in proportion to the particle surface area. The surface-controlled model better captures the spatial pattern of observed

  4. Feasibility of laser-separation of 36S and its use as an atmospheric tracer

    International Nuclear Information System (INIS)

    Herman, I.P.

    1981-01-01

    This report addresses one of the possible uses of isotopic tracers, produced by laser-assisted iostope separation, in the investigation of pollution problems. Specifically, the use of laser-produced sulfur isotopes to analyze the acid rain situation is considered as it is a most important application of this technique. The proposed use of isotopically-labelled SO 2 , in particular of 36 SO 2 , as a tracer can help elucidate the chemical and transport facets in a unified experiment. Separation of a sufficient quantity of the rare 36 S isotope to perform several of these tracer studies appears to be practical and economical. This overall process is certainly deserving of further investigation

  5. Tagging moisture sources with Lagrangian and inertial tracers: application to intense atmospheric river events

    Directory of Open Access Journals (Sweden)

    V. Pérez-Muñuzuri

    2018-06-01

    Full Text Available Two Lagrangian tracer tools are evaluated for studies on atmospheric moisture sources and pathways. In these methods, a moisture volume is assigned to each particle, which is then advected by the wind flow. Usual Lagrangian methods consider this volume to remain constant and the particle to follow flow path lines exactly. In a different approach, the initial moisture volume can be considered to depend on time as it is advected by the flow due to thermodynamic processes. In this case, the tracer volume drag must be taken into account. Equations have been implemented and moisture convection was taken into account for both Lagrangian and inertial models. We apply these methods to evaluate the intense atmospheric rivers that devastated (i the Pacific Northwest region of the US and (ii the western Iberian Peninsula with flooding rains and intense winds in early November 2006 and 20 May 1994, respectively. We note that the usual Lagrangian method underestimates moisture availability in the continent, while active tracers achieve more realistic results.

  6. ZZ SIESTA, Atmospheric Dispersion Experiment over Complex Terrain

    International Nuclear Information System (INIS)

    2000-01-01

    1 - Name of experiment: SIESTA. 2 - Computer for which program is designed and other machine version packages available: To request or retrieve programs click on the one of the active versions below. A password and special authorization is required. Explanation of the status codes. Program-name: ZZ-SIESTA; Package-ID Status: NEA-1617/01 Tested; Machines used: Package-ID: NEA-1617/01; Orig. Computer: DEC VAX 6000; Test Computer: DEC VAX 6000. 3 - Purpose and phenomena tested: The aim of the project was to obtain knowledge of the general nature of the turbulence, advection and atmospheric dispersion in the two flow regimes parallel to the Swiss Jura ridge, which represent the most frequent wind systems occurring on the Swiss Plain. 4 - Description of the experimental set-up used: The atmospheric dispersion process was investigated by carrying out SF 6 tracer experiments. The tracer was released about 6 m above ground level near the Goesgen meteo tower. Sampling units were placed on ellipses around the release point. Total sampling time was at least one hour. Tracer concentrations were determined after each experiment by Gas chromatography. 5 - Special features: Because of the uncertainty in the transport direction of the tracer plume, a mobile tracer analyzing system was used. 6 - Description of experiment and analysis: To investigate the flow field in the test region, the following measuring setups were used: (1) Three tethered balloon sounding systems to measure temperature, humidity, wind speed and direction; (2) a meteo tower to measure 10-minute averages of wind direction and velocity at two fixed heights; (3) sonic anemometers to measure heat flux, friction velocity, Monin-Obukhov length, and wind speed at the release point and at a certain distance; (4) 2-m masts to measure wind speed and direction continuously. The wind flow system was measured by radar-tracked tetroons

  7. Verification of atmospheric diffusion models with data of atmospheric diffusion experiments

    International Nuclear Information System (INIS)

    Hato, Shinji; Homma, Toshimitsu

    2009-02-01

    The atmospheric diffusion experiments were implemented by Japan Atomic Energy Research Institute (JAERI) around Mount Tsukuba in 1989 and 1990, and the tracer gas concentration were monitored. In this study, the Gauss Plume Model and RAMS/HYPACT that are meteorological forecast code and atmospheric diffusion code with detailed physical law are made a comparison between monitored concentration. In conclusion, the Gauss Plume Model is better than RAM/HYPACT even complex topography if the estimation is around tens of kilometer form release point and the change in weather is constant for short time. This reason is difference of wind between RAMS and observation. (author)

  8. Tracer simulation using a global general circulation model: Results from a midlatitude instantaneous source experiment

    International Nuclear Information System (INIS)

    Mahlman, J.D.; Moxim, W.J.

    1978-01-01

    An 11-level general circulation model with seasonal variation is used to perform an experiment on the dispersion of passive tracers. Specially constructed time-dependent winds from this model are used as input to a separate tracer model. The methodologies employed to construct the tracer model are described.The experiment presented is the evolution of a hypothetical instantaneous source of tracer on 1 Janaury with maximum initial concentration at 65 mb, 36 0 N, 180 0 E. The tracer is assumed to have no sources or sinks in the stratosphere, but is subject to removal processes in the lower troposphere.The experimental results reveal a number of similarities to observed tracer behavior, including the average poleward-downward slope of mixing ratio isopleths, strong tracer gradients across the tropopause, intrusion of tracer into the Southern Hemisphere lower stratosphere, and the long-term interhemispheric exchange rate. The model residence times show behavior intermediate to those exhibited for particulate radioactive debris and gaseous C 14 O 2 . This suggests that caution should be employed when either radioactive debris or C 14 O 2 data are used to develop empirical models for prediction of gaseous tracers which are efficiently removed in the troposphere.In this experiment, the tracer mixing ratio and potential vorticity evolve to very high correlations. Mechanisms for this correlation are discussed. The zonal mean tracer balances exhibit complex behavior among the various transport terms. At early stages, the tracer evolution is dominated by eddy effects. Later, a very large degree of self-cancellation between mean cell and eddy effects is observed. During seasonal transitions, however, this self-cancellation diminishes markedly, leading to significant changes in the zonal mean tracer distribution. A possible theoretical explanation is presented

  9. Site characterization and validation - Tracer migration experiment in the validation drift, report 2, part 1: performed experiments, results and evaluation

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.; Moreno, L.

    1992-01-01

    This report is the second of the two reports describing the tracer migration experiment where water and tracer flow has been monitored in a drift at the 385 m level in the Stripa experimental mine. The tracer migration experiment is one of a large number of experiments performed within the Site Characterization and Validation (SCV) project. The upper part of the 50 m long validation drift was covered with approximately 150 plastic sheets, in which the emerging water was collected. The water emerging into the lower part of the drift was collected in short boreholes, sumpholes. Sex different tracer mixtures were injected at distances between 10 and 25 m from the drift. The flowrate and tracer monitoring continued for ten months. Tracer breakthrough curves and flowrate distributions were used to study flow paths, velocities, hydraulic conductivities, dispersivities, interaction with the rock matrix and channelling effects within the rock. The present report describes the structure of the observations, the flowrate measurements and estimated hydraulic conductivities. The main part of this report addresses the interpretation of the tracer movement in fractured rock. The tracer movement as measured by the more than 150 individual tracer curves has been analysed with the traditional advection-dispersion model and a subset of the curves with the advection-dispersion-diffusion model. The tracer experiments have permitted the flow porosity, dispersion and interaction with the rock matrix to be studied. (57 refs.)

  10. Downscale cascades in tracer transport test cases: an intercomparison of the dynamical cores in the Community Atmosphere Model CAM5

    Directory of Open Access Journals (Sweden)

    J. Kent

    2012-12-01

    Full Text Available The accurate modeling of cascades to unresolved scales is an important part of the tracer transport component of dynamical cores of weather and climate models. This paper aims to investigate the ability of the advection schemes in the National Center for Atmospheric Research's Community Atmosphere Model version 5 (CAM5 to model this cascade. In order to quantify the effects of the different advection schemes in CAM5, four two-dimensional tracer transport test cases are presented. Three of the tests stretch the tracer below the scale of coarse resolution grids to ensure the downscale cascade of tracer variance. These results are compared with a high resolution reference solution, which is simulated on a resolution fine enough to resolve the tracer during the test. The fourth test has two separate flow cells, and is designed so that any tracer in the western hemisphere should not pass into the eastern hemisphere. This is to test whether the diffusion in transport schemes, often in the form of explicit hyper-diffusion terms or implicit through monotonic limiters, contains unphysical mixing.

    An intercomparison of three of the dynamical cores of the National Center for Atmospheric Research's Community Atmosphere Model version 5 is performed. The results show that the finite-volume (CAM-FV and spectral element (CAM-SE dynamical cores model the downscale cascade of tracer variance better than the semi-Lagrangian transport scheme of the Eulerian spectral transform core (CAM-EUL. Each scheme tested produces unphysical mass in the eastern hemisphere of the separate cells test.

  11. Tracer gas experiment to verify the dispersion from a tall stack

    International Nuclear Information System (INIS)

    Sivertsen, B.; Irwin, J.S.

    1996-01-01

    At the request of the Ministerios de Obras Publicas y Urbanismo (MOPU) in Madrid, the Norwegian Institute for Air Research (NILU) planned and carried out a comprehensive field experiment at the Andorra (Teruel) power plant in Spain. All together, eleven releases of sulfur hexafluoride (SF6) tracer were carried out at the 1,200 MW electric coal fired power plant. The tracer was emitted into the atmosphere from the 343 m high stack, stack exit diameter of 9 m. The stack gas emission characteristics were nearly constant during the period having an exit temperature of 175.1 C (1.9), exit velocity of 35.5 m/s (0.14) and sulfur dioxide (SO 2 ) emission rate of 46.1 x 10 3 kg/hr (5.15 x 10 3 ); standard deviations are listed in parentheses. Samples were taken at the surface along sampling arcs located approximately 8, 23, 43 and 75 km downwind. The releases were undertaken during typical late spring daytime conditions. The synoptic weather conditions were dominated by a large high pressure system on the Atlantic, west of Spain. Fronts were passing the area from the north and a low pressure system was developing over central Europe (Germany). Winds at the surface were generally brisk from the northwest at 7 to 12 m/s

  12. GTS-LCS, in-situ experiment 2. Modeling of tracer test 09-03

    International Nuclear Information System (INIS)

    Manette, M.; Saaltink, M.W.; Soler, J.M.

    2015-02-01

    Within the framework of the GTS-LCS project (Grimsel Test Site - Long-Term Cement Studies), an in-situ experiment lasting about 5 years was started in 2009 to study water-cement-rock interactions in a fractured granite. Prior to the experiment, a tracer test was performed to characterize the initial flow and transport properties of the rock around the experimental boreholes. This study reports on the model interpretation of tracer test 09-03. The calculations were performed by means of a two-dimensional model (homogeneous fracture plane including 3 boreholes) using the Retraso-CodeBright software package. In the tracer test, Grimsel groundwater containing the tracer (uranine) was circulated in the emplacement borehole during 43 days (zero injection flow rate). Circulation continued without tracer afterwards. Water was extracted at the observation and extraction boreholes. Results from a model sensitivity analysis comparing model results with measured tracer concentrations showed 3 cases where the evolution of tracer concentrations in the 3 different boreholes was satisfactory. In these cases a low-permeability skin affected the emplacement and observation boreholes. No skin appeared to affect the extraction borehole. The background hydraulic gradient seems to have no effect on the results of the tracer test. These results will be applied in the calculation of the initial flow field for the reactive transport phase of in-situ experiment 2 (interaction between pre-hardened cement and fractured granite at Grimsel). (orig.)

  13. Tracer tests and image analysis of biological clogging in a two-dimentsional sandbox experiment

    DEFF Research Database (Denmark)

    Kildsgaard, J.; Engesgaard, Peter Knudegaard

    2002-01-01

    A two-dimensional flow experiment on biological clogging was carried out by biostimulating a sandbox packed with sand inoculated with bacteria. Biostimulation. consisted of continuously injecting nutrients (acetate and nitrate). Clogging was visualized by frequently carrying out colored tracer...... experiments using Brilliant Blue. The tracer experiments were recorded with a digital camera and converted to concentration maps using an image-analysis method that revealed in detail the complex spreading pattern surrounding clogged areas. Clogging resulted in a finger-like spreading of the tracer around...

  14. Inverse constraints for emission fluxes of atmospheric tracers estimated from concentration measurements and Lagrangian transport

    Science.gov (United States)

    Pisso, Ignacio; Patra, Prabir; Breivik, Knut

    2015-04-01

    Lagrangian transport models based on times series of Eulerian fields provide a computationally affordable way of achieving very high resolution for limited areas and time periods. This makes them especially suitable for the analysis of point-wise measurements of atmospheric tracers. We present an application illustrated with examples of greenhouse gases from anthropogenic emissions in urban areas and biogenic emissions in Japan and of pollutants in the Arctic. We asses the algorithmic complexity of the numerical implementation as well as the use of non-procedural techniques such as Object-Oriented programming. We discuss aspects related to the quantification of uncertainty from prior information in the presence of model error and limited number of observations. The case of non-linear constraints is explored using direct numerical optimisation methods.

  15. 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

  16. Numerical Simulation of a Tracer Experiment at the Wolsong Nuclear Site

    International Nuclear Information System (INIS)

    Jeong, Hyojoon; Kim, Eunhan; Park, Misun; Jeong, Haesun; Hwang, Wontae; Han, Moonhee

    2014-01-01

    By comparing the concentration of a tracer measured under weather conditions that are disadvantageous to the dilution of radioactive materials released from the Wolsong Nuclear Power Plant, with the concentration of a tracer calculated using an air Dispersion model, it is possible to evaluate the characteristics of the air concentrations of radioactive materials estimated with an air Dispersion model, which can then be used in an environmental impact analysis of radioactive materials. Therefore, a field Dispersion experiment has been carried out to figure out the behavioral characteristics of the tracer under weather conditions that are disadvantageous to the dilution of radioactive materials released from the Wolsong Nuclear Power Plant site in Korea. In addition, through a comparison of the tracer concentrations estimated by the Gaussian plume model with measurements, this study checked the degree of conservative estimation for the Gaussian plume at the Wolsong nuclear site in Korea. A tracer Dispersion experiment using an SF 6 trace was implemented to determine the Dispersion characteristics of radioactive materials at the Wolsong Nuclear Power Plant site in Korea. Based on meteorological data and the emission rate of the tracers, this study estimated the tracer concentrations using a Gaussian plume model, and then compared it with the measurement to check the conservative estimation of the Gaussian plume model. The measured concentrations of the tracer tends to be lower than the concentrations estimated by the Gaussian plume model overall

  17. Accuracy of tracer stimulus response experiments in laminar flows

    Czech Academy of Sciences Publication Activity Database

    Chlup, Hynek; Novotný, Pavel; Žitný, R.

    2012-01-01

    Roč. 55, 23-24 (2012), s. 6458-6462 ISSN 0017-9310 Institutional research plan: CEZ:AV0Z20760514 Keywords : residence time distribution * tracer injection * laminar convective dominated flow Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 2.315, year: 2012 http://www.sciencedirect.com/science/article/pii/S001793101200470X

  18. Tracer tests - possibilities and limitations. Experience from SKB fieldwork: 1977-2007

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Martin; Crawford, James; Elert, Mark (Kemakta Konsult AB, Stockholm (SE))

    2007-09-15

    Tracer tests have played, and still play, a central role in investigations relating to the understanding of radionuclide retention processes in the field. At present there is a debate within the scientific community concerning how, and to what extent, tracer tests can be used to evaluate large-scale and long-term transport and retardation of radionuclides and other solutes of interest for Safety Assessment of repositories for spent nuclear fuel. In this report the SKB fieldwork on tracer tests performed at Swedish sites from 1977 to 2007 is described and discussed. Furthermore, the knowledge and process understanding evolved during the decades of radionuclide transport experiments and modelling within the SKB programme is summarised. One of the main objectives of this report is to discuss what data and knowledge can be extracted from different in situ tests in a robust fashion. Given the level of complexity associated with transport processes that may occur over the timescale of a tracer test, the utility of tracer tests is considered in the context of evidence-based interpretations of data which we characterise in the form of a sequence of questions of increasing complexity. The complexity of this sequence ranges from whether connection can be confirmed between injection and withdrawal points to whether quantitative data can be extrapolated from a tracer test to be subsequently used in Safety Assessment. The main findings of this report are that: Field scale tracer tests can confirm flow connectivity. Field scale tracer tests confirm the existence of retention. Field scale tracer tests alone can only broadly substantiate our process understanding. However, if performing extensive Site Characterisation and integrating the tracer test results with the full range of geoscientific information available, much support can be given to our process understanding. Field scale tracer tests can deliver the product of the material property group MPG and the F-factor, valid

  19. Haze in the Grand Canyon: An evaluation of the Winter Haze Intensive Tracer Experiment

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    The Grand Canyon is one of the most spectacular natural sights on earth. Approximately 4 million visitors travel to Grand Canyon National Park (GCNP) each year to enjoy its majestic geological formations and intensely colored views. However, visibility in GCNP can be impaired by small increases in concentrations of fine suspended particles that scatter and absorb light; the resulting visibility degradation is perceived as haze. Sulfate particles are a major factor in visibility impairment at Grand Canyon in summer and winter. Many wintertime hazes at GCNP are believed to result from the accumulation of emissions from local sources during conditions of air stagnation, which occur more frequently in winter than in summer. In January and February 1987, the National Park Service (NPS) carried out a large-scale experiment known as the Winter Haze Intensive Tracer Experiment (WHITEX) to investigate the causes of wintertime haze in the region of GCNP and Canyonlands National Park. The overall objective of WHITEX was to assess the feasibility of attributing visibility impairment in specific geographic regions to emissions from a single point source. The experiment called for the injection of a tracer, deuterated methane (CD{sub 4}), into one of the stacks of the Navajo Generating Station (NGS), a major coal-fired power plant located 25 km from the GCNP boundary and 110 km northeast of Grand Canyon Village. A network of field stations was established in the vicinity -- mostly to the northeast of GCNP and NGS -- to measure CD{sub 4} concentrations, atmospheric aerosol and optical properties, and other chemical and physical attributes. 19 refs., 3 figs.

  20. Interpretation of field experiments on the flow of water and tracers through crystalline rock

    International Nuclear Information System (INIS)

    Hodgkinson, D.P.; Lever, D.A.; Robinson, P.C.; Bourke, P.J.

    1983-01-01

    This paper reviews recent work at Harwell on the interpretation of field experiments on the flow of water and tracers through crystalline rock. First a model for the radial transport of tracers through an isolated fracture is outlined and used to analyse a recent Swedish experiment at Finnsjoen. Secondly, the theoretical and experimental approach that is being used to quantify flow and dispersion through networks of fractures is described

  1. A comparison of measurements and calculations for the Stripa tracer experiments

    International Nuclear Information System (INIS)

    Hodgkinson, D.P.; Copper, N.S.

    1992-03-01

    This paper presents a comparison of measurements and predictions for migration of tracers from boreholes to the validation drift and to other boreholes in the Site Characterisation and Validation (SCV) block. The comparison was carried out on behalf of the Stripa task force on fracture flow modelling. The paper summarises the radar/saline tracer experiments, the tracer migration experiment observations and reviews the fracture flow and tracer transport modelling approaches and predictions made by AEA Technology, Fracflow Consultants, Golder Associates and Lawrence Berkeley Laboratory. The predictions are compared with the observed breakthrough curves on the basis of the validation process and criteria defined by the task force. The results of all four modelling groups met the validation criteria, with the predictions of the tracer breakthrough concentrations and times being within an order of magnitude of the observations. Also the AEA and Golder approaches allow the spatial distribution of tracer breakthrough into the validation drift to be predicted and these predictions also showed reasonable accuracy. The successful completion of this project demonstrates the feasibility of discrete fracture flow and tracer transport modelling. (36 refs.) (au)

  2. Movement of iodine and rain water from the atmosphere to the plant - soil - water system by the activable tracer techniques

    International Nuclear Information System (INIS)

    Yuita, Kouichi

    1996-01-01

    Iodine is one of the important elements in the environmental and agricultural sciences. It is requested to elucidate the long-term behavior of iodine in the atmosphere - soil·plant - soil water system. We developed the new tracer method, in which iodine released into the atmosphere from the stack of iodine manufacturing plant in Chiba prefecture was used as the activable tracer. Using this method, we traced the direct deposition of iodine in atmosphere onto the plant tops and the penetration of fallout iodine into soil in an open air over a long period. A quantitative evaluation of recharge function of water resources in agricultural and forest lands of Japan was eagerly requested from the nation. For it, we developed the new Br - tracer method combined with the soil water sampling system with the alumina porous ceramic cup. This tracer method was successfully applied to the agricultural and forest land in the catchment area of Sakawa river in Kanagawa prefecture. And the infiltration rate of the rain water and irrigation water, from the soil surface to the dept of 3m of the soil horizon in the forest land, tea garden and paddy field was quantitatively measured during two years. (J.P.N.)

  3. Keeping the secret: Insights from repeated catchment-scale tracer experiments under transient conditions

    Science.gov (United States)

    Bogner, Christina; Hauhs, Michael; Lange, Holger

    2016-04-01

    Catchment-level tracer experiments are generally performed to identify site-specific hydrological response functions of the catchment. The existence and uniqueness of these response functions are hardly ever questioned. Here, we report on a series of replicated tracer experiments in two small first-order catchments, G1 (0.6 ha, roofed) and F4 (2.3 ha, without roof) at Gårdsjön in SW Sweden. The soils in both catchments are shallow (500 m2) the experiments were done without a roof mostly at transient conditions. The catchment F4 was equipped with a sprinkler system with a watering capacity of around 38-45 m3 day-1. Natural rainfall comes in addition. A bromide tracer solution was injected to groundwater at a single location about 40 m upstream the weir over a period of less than an hour, and was monitored using a set of groundwater tubes and the weir at the outlet over the following 4 days. In addition, discharge was measured. The experiments were repeated each summer from 2007 to 2015. While steady state conditions were guaranteed in G1, steady runoff has been achieved only four times in F4. We investigated tracer recovery rates against cumulated runoff since tracer application. Substantially different transit times and qualitatively different behaviour of the breakthrough curves were observed, even under steady state conditions. In G1, no single system response function could be identified in 5 replicates. Similarly, the catchment response functions in F4 under steady state differed between experiments. However, they remained in a similar range as in G1. Based on these results, we question the identifiability of flow paths and system properties, such as saturated water content or hydrologic transmissivity, at the catchment scale using tracer experiments. Rather, the series demonstrate the utter importance of the initial and boundary conditions which largely determine the response of the system to inert tracer pulses.

  4. Use of radon-222 as a tracer in the study of atmospheric diffusion

    International Nuclear Information System (INIS)

    Ikebe, Y.; Yamada, H.; Nishimura, T.; Kojima, S.; Shimo, M.; Yamanishi, H.; Tojyo, K.; Iida, T.; Chino, M.

    1991-01-01

    222 Rn is one of the most useful tracer for studying the atmospheric diffusion. In this report, first we report analytical treatments about temporal variation of Rn concentration in the atmosphere to clarify origin and transport of Rn. Secondly we report the numerical simulation of the behavior of Rn. The results is compared with the observed Rn concentration for confirming the validity of the simulation. Based on the results of numerical analysis of a diffusion equation, we assumed that Rn concentration measured at Nagoya can be divided into the following two components: (I) Rn atom originated near from the measuring site, which is denoted by 'diurnal variation component'. For this, it was shown that the measured temporal variation can be explained by using ordinary non-steady state one dimensional diffusion equation. (II) Rn atoms originated far from the measuring site (including Chinese Continent), which is denoted by 'background component'. For this component, we propose a one layer transport model using air mass trajectory technique. By this model we can explain well the temporal variation of back-ground component and seasonal variation of Rn at Nagoya. A numerical simulation of the temporal variation of Rn was carried out for meso-regional scale (200kmx200kmx1km). The results was compared with the continuous measurements of Rn concentration at Nagoya, and fairly good agreements was obtained. We have obtained horizontal distributions of Rn around Nagoya (150kmx150km) for each season by using a passive method. The linear relationship between Rn concentration and measured Rn exhalation rate supports the transport model mentioned above and gives us other interesting informations. (author)

  5. Remarks relating to field experiments to measure the wet scavenging of tracer aerosols

    International Nuclear Information System (INIS)

    Stensland, G.J.

    1977-12-01

    An important question is whether or not the wet deposition of debris from a single (or multiple) airburst of a nuclear device poses a significant hazard to people on the ground. To answer this question for various scenarios, a basic understanding of the aerosol attachment rates to cloud water and raindrops is needed. The attachment rates can then be incorporated into the cloud physics scavenging models to make intelligent assessments. In order to gain an initial impression as to the importance (order of magnitude) of the wet scavenging effects and to provide the data to validate the cloud scavenging models, tracer release field experiments are useful and necessary. The major purpose of this report is to address questions related to the operation and interpretation of such field tracer efforts and in particular to consider the results from the August 3, 1972, Battelle Northwest Laboratory tracer experiment in St. Louis. The Battelle experiment involved the release of several aerosol tracers at 10,000 to 13,000 feet, near rain clouds, and the measurement of the resulting tracer in the rain collected at the ground level sampling sites

  6. Seasonal cycles of secondary organic aerosol tracers in rural Guangzhou, Southern China: The importance of atmospheric oxidants.

    Science.gov (United States)

    Yuan, Qi; Lai, Senchao; Song, Junwei; Ding, Xiang; Zheng, Lishan; Wang, Xinming; Zhao, Yan; Zheng, Junyu; Yue, Dingli; Zhong, Liuju; Niu, Xiaojun; Zhang, Yingyi

    2018-05-21

    Thirteen secondary organic aerosol (SOA) tracers of isoprene (SOA I ), monoterpenes (SOA M ), sesquiterpenes (SOA S ) and aromatics (SOA A ) in fine particulate matter (PM 2.5 ) were measured at a Pearl River Delta (PRD) regional site for one year. The characteristics including their seasonal cycles and the factors influencing their formation in this region were studied. The seasonal patterns of SOA I , SOA M and SOA S tracers were characterized over three enhancement periods in summer (I), autumn (II) and winter (III), while the elevations of SOA A tracer (i.e., 2,3-dihydroxy-4-oxopentanoic acid, DHOPA) were observed in Periods II and III. We found that SOA formed from different biogenic precursors could be driven by several factors during a one-year seasonal cycle. Isoprene emission controlled SOA I formation throughout the year, while monoterpene and sesquiterpene emissions facilitated SOA M and SOA S formation in summer rather than in other seasons. The influence of atmospheric oxidants (O x ) was found to be an important factor of the formation of SOA M tracers during the enhancement periods in autumn and winter. The formation of SOA S tracer was influenced by the precursor emissions in summer, atmospheric oxidation in autumn and probably also by biomass burning in both summer and winter. In this study, we could not see the strong contribution of biomass burning to DHOPA as suggested by previous studies in this region. Instead, good correlations between observed DHOPA and O x as well as [NO 2 ][O 3 ] suggest the involvement of both ozone (O 3 ) and nitrogen dioxide (NO 2 ) in the formation of DHOPA. The results showed that regional air pollution may not only increase the emissions of aromatic precursors but also can greatly promote the formation processes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Two dimensional model study of atmospheric transport using carbon-14 and strontium-90 as inert tracers

    International Nuclear Information System (INIS)

    Kinnison, D.E.; Wuebbles, D.J.; Johnston, H.S.

    1992-02-01

    This study tests the transport processes in the LLNL two-dimensional chemical-radiative-transport model using recently reanalyzed carbon-14 and strontium-90 data. These radioactive tracers were produced bythe atmospheric nuclear bomb tests of 1952--58 and 1961--62, and they were measured at a few latitudes up to 35 kilometers over the period 1955--1970. Selected horizontal and vertical eddy diffusion coefficients were varied in the model to test their sensitivity to short and long term transpose of carbon-14. A sharp transition of K zz and K yy through the tropopause, as opposed to a slow transition between the same limiting values, shows a distinct improvement in the calculated carbon-14 distributions, a distinct improvement in the calculated seasonal and latitudinal distribution of ozone columns (relative to TOMS observations), and a very large difference in the calculated ozone reduction by a possible fleet of High Speed Civil Transports. Calculated northern hemisphere carbon-14 is more sensitive to variation of K yy than are global ozone columns. Strontium-90 was used to test the LLNL tropopause height at four different latitudes. Starting with the 1960 background distribution of carbon-14, we calculate the input of carbon-14 as the sum of each nuclear test of the 1961--62 series, using two bomb-cloud rise models. With the Seitz bomb-rise formulation in the LLNL model, we find good agreement between calculated and observedcarbon-14 (with noticeable exceptions at the north polar tropopause and the short-term mid-latitude mid-stratosphere) between 1963 and 1970

  8. Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

    Science.gov (United States)

    Klepikova, Maria; Wildemeersch, Samuel; Hermans, Thomas; Jamin, Pierre; Orban, Philippe; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

    2016-09-01

    Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

  9. Development of X-ray tracer diagnostics for radiatively-driven ablator experiments

    International Nuclear Information System (INIS)

    MacFarlane, J.J.; Cohen, D.H.; Wang, P.; Moses, G.A.; Peterson, R.R.; Jaanimagi, P.A.; Langen, O.L.; Olson, R.E.; Murphy, T.J.; Magelssen, G.R.; Delamater, N.D.

    1999-01-01

    This report covers fiscal year 1998 of our ongoing project to develop tracer X-ray spectroscopic diagnostics for hohlraum environments. This effort focused on an experimental campaign carried out at OMEGA on 25--27 August 1998. This phase of the project heavily emphasized experimental design, diagnostic development, and target fabrication, as well as building up numerical models for the experiments. The spectral diagnostic under development involves using two thin (few 1000 Angstroem) mid-Z tracers in two witness plates mounted on the side of a hohlraum with the tracers' K a absorption features seen against an X-ray backlighter. The absorption data are used to sample the time-dependent, localized properties of each witness plate as a radiation wave ablates it. The experiments represented the first application of this diagnostic, in this case to side-by-side doped and undoped plastic to investigate the effects of capsule ablator dopants

  10. The data analysis of the single well injection-withdraw tracer experiment using the MACRO II

    International Nuclear Information System (INIS)

    Shirakawa, Toshihiko; Kanazawa, Yasuo; Hatanaka, Koichiro

    2001-04-01

    On understanding the radionuclide transport in natural barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, we have conducted lots of tracer experiments by the MACRO II facility with an artificially constructed heterogeneous permeability field. In order to study the scale dependence of dispersion coefficients in case of laboratory experiments, we placed the flow cell horizontally, and conducted injection-withdraw tracer experiment with a single well. We have conducted 15 cases experiments. These cases were prepared by changing a position of single well and the injection-withdraw time. At each position we have conducted 9 cases and 6 cases experiments. In this report, we evaluated the macroscopic dispersion coefficients by the fitting of analytical solution to breakthrough curve measured by the 15 cases pumping tracer experiment. Consequently, we could evaluate the dispersion coefficients for 12 cases of 15 cases. Then, we discussed the relation between a injection-withdraw flow rate and a property of heterogeneous media and dispersion coefficient. The conclusions obtained from the results of the evaluation are summarized as follows, It was found that the macroscopic dispersion coefficients tend to be increased with increase of the average radius of tracer front spread around a single well. We have conducted any experiments with s single well settled at two positions. In case of that there is low permeability around a single well, we found dispersion coefficients are large. In case of that there is high permeability around a single well, we found dispersion coefficients are small. In three cases that we could not evaluate because of incorrect accuracy of fitting, we have found it possible that there is some points that dispersion coefficients were strikingly small in tracer front. (author)

  11. Atmospheric Tracer Depletion Testing for Unfiltered Air In-Leakage Determination at the Wolf Creek Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wilke, R. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roberts, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vignato, G. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-03-01

    Atmospheric Tracer Depletion tests were conducted at the Wolf Creek Nuclear Power Plant to quantify the unfiltered in-leakage (UI) into the Control Room (CR), Control Building (CB), and Equipment Rooms (ER) at the Wolf Creek Nuclear Power Plant. Wolf Creek has two independent charcoal filter Emergency Ventilation Systems (EVS) that can be used to purify air entering the control building and control room. The Bravo System contains a filtration system in Room 1501 in the Auxiliary Building for the Control Room and another filtration system (FGK02B) on Elevation 2016 for the Control Building. The Alpha system contains a filtration system in Room 1512 in the Auxiliary Building for the Control Room and another filtration system (FGK02A) on Elevation 2016 for the Control Building. The Atmospheric Tracer Depletion (ATD) test is a technique to measure in-leakage using the concentration of perfluorocarbon compounds that have a constant atmospheric background. These levels are present in the Control Room and Control Building under normal operating conditions. When air is supplied by either of the EVS, most of the PFTS are removed by the charcoal filters. If the concentrations of the PFTs measured in protected areas are the same as the levels at the output of the EVS, the in-leakage of outside air into the protected area would be zero. If the concentration is higher in the protected area than at the output of the filter system, there is in-leakage and the in-leakage can be quantified by the difference. Sampling was performed using state-of-the-art Brookhaven Atmospheric Tracer Samplers (BATS) air sampling equipment and analysis performed on Brookhaven National Laboratory (BNL) dedicated PFT analytical systems. In the Alpha test two tracers PMCH and mcPDCH were used to determine in-leakage into the control building. The analytical system was tuned to maximize sensitivity after initial analysis of the Alpha test. The increased sensitivity permitted accurate quantification of

  12. Atmospheric Tracer Depletion Testing for Unfiltered Air In-Leakage Determination at the Wolf Creek Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wilke, R. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roberts, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Vignato, G. J. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-04-01

    Atmospheric Tracer Depletion tests were conducted at the Wolf Creek Nuclear Power Plant to quantify the unfiltered in-leakage (UI) into the Control Room (CR), Control Building (CB), and Equipment Rooms (ER) at the Wolf Creek Nuclear Power Plant. Wolf Creek has two independent charcoal filter Emergency Ventilation Systems (EVS) that can be used to purify air entering the control building and control room. The Bravo System contains a filtration system in Room 1501 in the Auxiliary Building for the Control Room and another filtration system (FGK02B) on Elevation 2016 for the Control Building. The Alpha system contains a filtration system in Room 1512 in the Auxiliary Building for the Control Room and another filtration system (FGK02A) on Elevation 2016 for the Control Building.The Atmospheric Tracer Depletion (ATD) test is a technique to measure in-leakage using the concentration of perfluorocarbon compounds that have a constant atmospheric background. These levels are present in the Control Room and Control Building under normal operating conditions. When air is supplied by either of the EVS, most of the PFTS are removed by the charcoal filters. If the concentrations of the PFTs measured in protected areas are the same as the levels at the output of the EVS, the in-leakage of outside air into the protected area would be zero. If the concentration is higher in the protected area than at the output of the filter system, there is in-leakage and the in-leakage can be quantified by the difference.Sampling was performed using state-of-the-art Brookhaven Atmospheric Tracer Samplers (BATS) air sampling equipment and analysis performed on Brookhaven National Laboratory (BNL) dedicated PFT analytical systems. In the Alpha test two tracers PMCH and mcPDCH were used to determine in-leakage into the control building. The analytical system was tuned to maximize sensitivity after initial analysis of the Alpha test. The increased sensitivity permitted accurate quantification of five

  13. GRIP LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Lidar Atmospheric Sensing Experiment (LASE) dataset was collected by NASA's Lidar Atmospheric Sensing Experiment (LASE) system, which is an airborne...

  14. Isotopes as tracers of the oceanic circulation: Results from the World Ocean Circulation Experiment

    International Nuclear Information System (INIS)

    Schlosser, P.; Jenkins, W.J.; Key, R.; Lupton, J.

    2002-01-01

    During the past decades, natural and anthropogenic isotopes such as tritium ( 3 H), radiocarbon ( 14 C), 3 He, or the stable isotopes of water have been used in studies of the dynamics of natural systems. Early applications of tracers to studies of the ocean were directed at determination of circulation patterns and mean residence times of specific water masses, as well as estimates of mixing coefficients. These exploratory studies suggested that tracers can add significantly to our understanding of the oceanic circulation. In order to fully exploit this potential, the first global tracer study, the GEochemical Ocean SECtions Study (GEOSECS), was launched. From the GEOSECS results it was immediately apparent that very close coordination of tracer programs with physical oceanography studies is required for full utilization of tracer data. During the 1980s plans for the World OCean Experiment (WOCE) were developed. As part of its Hydrographic Program (WHP), especially during the one-time survey, a set of tracers were measured on a global scale with unprecedented spatial resolution (both lateral and vertical). The original plan included a larger number of tracers (CFCs, 3 H/ 3 He, 14 C, 39 Ar, stable isotopes of water, helium isotopes, 228 Ra, 90 Sr, 137 Cs, 85 Kr) than could actually be measured systematically (CFCs, 3 H/ 3 He, 14 C, H 2 18 O/H 2 16 O, helium isotopes). Nevertheless, the resulting data set, which presently is under evaluation, exceeds those obtained from pre-WOCE tracer studies by a wide margin. In this contribution, we describe the existing WOCE data set and demonstrate the type of results that can be expected from its interpretation on the basis of a few selected examples. These examples include: (1) the application of tritium and 3 He to studies of the ventilation of the upper waters in the Pacific Ocean, (2) the spreading of intermediate water in the Pacific and Indian oceans as derived from the distribution of 3 He, and (3) the evaluation of

  15. Representation of tropical deep convection in atmospheric models – Part 2: Tracer transport

    Directory of Open Access Journals (Sweden)

    C. R. Hoyle

    2011-08-01

    Full Text Available The tropical transport processes of 14 different models or model versions were compared, within the framework of the SCOUT-O3 (Stratospheric-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere project. The tested models range from the regional to the global scale, and include numerical weather prediction (NWP, chemical transport, and chemistry-climate models. Idealised tracers were used in order to prevent the model's chemistry schemes from influencing the results substantially, so that the effects of modelled transport could be isolated. We find large differences in the vertical transport of very short-lived tracers (with a lifetime of 6 h within the tropical troposphere. Peak convective outflow altitudes range from around 300 hPa to almost 100 hPa among the different models, and the upper tropospheric tracer mixing ratios differ by up to an order of magnitude. The timing of convective events is found to be different between the models, even among those which source their forcing data from the same NWP model (ECMWF. The differences are less pronounced for longer lived tracers, however they could have implications for modelling the halogen burden of the lowermost stratosphere through transport of species such as bromoform, or short-lived hydrocarbons into the lowermost stratosphere. The modelled tracer profiles are strongly influenced by the convective transport parameterisations, and different boundary layer mixing parameterisations also have a large impact on the modelled tracer profiles. Preferential locations for rapid transport from the surface into the upper troposphere are similar in all models, and are mostly concentrated over the western Pacific, the Maritime Continent and the Indian Ocean. In contrast, models do not indicate that upward transport is highest over western Africa.

  16. Meteorological tracers in regional planning

    International Nuclear Information System (INIS)

    Mueller, K.H.

    1974-11-01

    Atmospheric tracers can be used as indicators to study both the ventilation of an urban region and its dispersion meteorology for air pollutants. A correlation analysis applied to the space-time dependent tracer concentrations is able to give transfer functions, the structure and characteristic parameters of which describe the meteorological and topographical situation of the urban region and its surroundings in an integral manner. To reduce the number of persons usually involved in a tracer experiment an automatic air sampling system had to be developed

  17. Investigation of Groundwater Flow Variations near a Recharge Pond with Repeat Deliberate Tracer Experiments

    Directory of Open Access Journals (Sweden)

    Jordan F Clark

    2014-06-01

    Full Text Available Determining hydraulic connections and travel times between recharge facilities and production wells has become increasingly important for permitting and operating managed aquifer recharge (MAR sites, a water supply strategy that transfers surface water into aquifers for storage and later extraction. This knowledge is critical for examining water quality changes and assessing the potential for future contamination. Deliberate tracer experiments are the best method for determining travel times and identifying preferential flow paths between recharge sites over the time scales of weeks to a few years. This paper compares the results of two deliberate tracer experiments at Kraemer Basin, Orange County, CA, USA. Results from the first experiment, which was conducted in October 1998, showed that a region of highly transmissive sedimentary material extends down gradient from the basin for more than 3 km [1]. Mean groundwater velocities were determined to be approximately 2 km/year in this region based on the arrival time of the tracer center of mass. A second experiment was initiated in January 2008 to determine if travel times from this basin to monitoring and production wells changed during the past decade in response to new recharge conditions. Results indicate that flow near Kraemer Basin was stable, and travel times to most wells determined during both experiments agree within the experimental uncertainty.

  18. Results of atmospheric diffusion experiments, vol.3

    International Nuclear Information System (INIS)

    Kakuta, Michio; Hayashi, Takashi; Adachi, Takashi.

    1988-02-01

    An extensive study on 'Emergency monitoring and prediction code system' has been carried in JAERI since 1980. Six series of field experiments on atmospheric diffusion were conducted to develop and verify the prediction models for environmental concentration distribution following accidental release of radioactivity. Results of field experiments (Inland complex terrain, surface and elevated point sources) conducted in 15 - 19th October 1984 (TSUKUBA84) and in 6 - 10th November 1985 (TSUKUBA85) are contained in this volume. (author)

  19. Bayesian inverse modeling of the atmospheric transport and emissions of a controlled tracer release from a nuclear power plant

    International Nuclear Information System (INIS)

    Lucas, Donald D.; Simpson, Matthew; Cameron-Smith, Philip; Baskett, Ronald L.

    2017-01-01

    Probability distribution functions (PDFs) of model inputs that affect the transport and dispersion of a trace gas released from a coastal California nuclear power plant are quantified using ensemble simulations, machine-learning algorithms, and Bayesian inversion. The PDFs are constrained by observations of tracer concentrations and account for uncertainty in meteorology, transport, diffusion, and emissions. Meteorological uncertainty is calculated using an ensemble of simulations of the Weather Research and Forecasting (WRF) model that samples five categories of model inputs (initialization time, boundary layer physics, land surface model, nudging options, and reanalysis data). The WRF output is used to drive tens of thousands of FLEXPART dispersion simulations that sample a uniform distribution of six emissions inputs. Machine-learning algorithms are trained on the ensemble data and used to quantify the sources of ensemble variability and to infer, via inverse modeling, the values of the 11 model inputs most consistent with tracer measurements. We find a substantial ensemble spread in tracer concentrations (factors of 10 to 10 3 ), most of which is due to changing emissions inputs (about 80 %), though the cumulative effects of meteorological variations are not negligible. The performance of the inverse method is verified using synthetic observations generated from arbitrarily selected simulations. When applied to measurements from a controlled tracer release experiment, the inverse method satisfactorily determines the location, start time, duration and amount. In a 2 km x 2 km area of possible locations, the actual location is determined to within 200 m. The start time is determined to within 5 min out of 2 h, and the duration to within 50 min out of 4 h. Over a range of release amounts of 10 to 1000 kg, the estimated amount exceeds the actual amount of 146 kg by only 32 kg. The inversion also estimates probabilities of different WRF configurations. To best match

  20. Bayesian inverse modeling of the atmospheric transport and emissions of a controlled tracer release from a nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Donald D.; Simpson, Matthew; Cameron-Smith, Philip; Baskett, Ronald L. [Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2017-07-01

    Probability distribution functions (PDFs) of model inputs that affect the transport and dispersion of a trace gas released from a coastal California nuclear power plant are quantified using ensemble simulations, machine-learning algorithms, and Bayesian inversion. The PDFs are constrained by observations of tracer concentrations and account for uncertainty in meteorology, transport, diffusion, and emissions. Meteorological uncertainty is calculated using an ensemble of simulations of the Weather Research and Forecasting (WRF) model that samples five categories of model inputs (initialization time, boundary layer physics, land surface model, nudging options, and reanalysis data). The WRF output is used to drive tens of thousands of FLEXPART dispersion simulations that sample a uniform distribution of six emissions inputs. Machine-learning algorithms are trained on the ensemble data and used to quantify the sources of ensemble variability and to infer, via inverse modeling, the values of the 11 model inputs most consistent with tracer measurements. We find a substantial ensemble spread in tracer concentrations (factors of 10 to 10{sup 3}), most of which is due to changing emissions inputs (about 80 %), though the cumulative effects of meteorological variations are not negligible. The performance of the inverse method is verified using synthetic observations generated from arbitrarily selected simulations. When applied to measurements from a controlled tracer release experiment, the inverse method satisfactorily determines the location, start time, duration and amount. In a 2 km x 2 km area of possible locations, the actual location is determined to within 200 m. The start time is determined to within 5 min out of 2 h, and the duration to within 50 min out of 4 h. Over a range of release amounts of 10 to 1000 kg, the estimated amount exceeds the actual amount of 146 kg by only 32 kg. The inversion also estimates probabilities of different WRF configurations. To best

  1. Analysis of tracer responses in the BULLION Forced-Gradient Experiment at Pahute Mesa, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Reimus; Marc J. Haga

    1999-10-01

    This report presents an analysis of the tracer data from the BULLION forced-gradient experiment (FGE) conducted on Pahute Mesa at the Nevada Test Site from June 2, 1997 through August 28, 1997, for the Underground Test Area (UGTA) Program. It also serves to document the polystyrene microsphere data from the FGE. The FGE involved the injection of solute and colloid tracers into wells ER-20-6 No. 1 and ER-20-6 No. 2 while ER-20-6 No. 3 was pumped at approximately 116 gallons per minute (gpm). The experimental configuration and test design are described briefly in this report; more details are provided elsewhere (IT, 1996, 1997, 1998). The tracer responses in the various wells yielded valuable information about transport processes such as longitudinal dispersion, matrix diffusion and colloid transport in the hydrogeologic system in the vicinity of the BULLION nuclear test cavity. Parameter values describing these processes are derived from the semi-analytical model interpretations presented in this report. A companion report (IT, 1998) presents more detailed numerical modeling interpretations of the solute tracer responses.

  2. Analysis of tracer responses in the BULLION Forced-Gradient Experiment at Pahute Mesa, Nevada

    International Nuclear Information System (INIS)

    Reimus, Paul W.; Haga, Marc J.

    1999-01-01

    This report presents an analysis of the tracer data from the BULLION forced-gradient experiment (FGE) conducted on Pahute Mesa at the Nevada Test Site from June 2, 1997 through August 28, 1997, for the Underground Test Area (UGTA) Program. It also serves to document the polystyrene microsphere data from the FGE. The FGE involved the injection of solute and colloid tracers into wells ER-20-6 No. 1 and ER-20-6 No. 2 while ER-20-6 No. 3 was pumped at approximately 116 gallons per minute (gpm). The experimental configuration and test design are described briefly in this report; more details are provided elsewhere (IT, 1996, 1997, 1998). The tracer responses in the various wells yielded valuable information about transport processes such as longitudinal dispersion, matrix diffusion and colloid transport in the hydrogeologic system in the vicinity of the BULLION nuclear test cavity. Parameter values describing these processes are derived from the semi-analytical model interpretations presented in this report. A companion report (IT, 1998) presents more detailed numerical modeling interpretations of the solute tracer responses

  3. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, A. [Conterra AB, Uppsala (Sweden); Andersson, Peter [Geosigma AB, Uppsala (Sweden); Hermanson, Jan [Golder Grundteknik, Solna (Sweden); Byegaard, Johan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Cvetkovic, V. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Water Resources Engineering; Birgersson, Lars [Kemakta Konsult AB, Stockholm (Sweden)

    2000-03-15

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (< 0.5 m), detailed scale (< 10 m) and block scale (10-50 m). The First TRUE Stage was performed in the detailed scale with the specific objectives of providing data and conceptualising the investigated feature using conservative and sorbing tracers. Further, to improve methodologies for performing tracer tests, and to develop and test a methodology for obtaining pore volume/aperture data from epoxy resin injection, excavation and subsequent analyses. The experimental site is located at approximately 400 m depth in the northeastern part of the Aespoe Hard Rock Laboratory. The identification of conductive fractures and the target feature has benefited from the use of BIPS borehole TV imaging combined with detailed flow logging. The assessment of the conductive geometry has been further sustained by cross-hole pressure interference data. The investigated target feature (Feature A) is a reactivated mylonite which has later undergone brittle deformation. The feature is oriented northwest, along the principal horizontal stress orientation, and is a typical conductor for Aespoe conditions. Hydraulic characterisation shows that the feature is relatively well isolated

  4. Ground water pollution by roof runoff infiltration evidenced with multi-tracer experiments.

    Science.gov (United States)

    Ammann, Adrian A; Hoehn, Eduard; Koch, Sabine

    2003-03-01

    The infiltration of urban roof runoff into well permeable subsurface material may have adverse effects on the ground water quality and endanger drinking water resources. Precipitation water from three different roofs of an industrial complex was channelled to a pit and infiltrated into a perialpine glaciofluvial gravel-and-sand aquifer. A shaft was constructed at the bottom of the pit and equipped with an array of TDR probes, lysimeters and suction cups that allowed measuring and sampling soil water at different depths. A fast infiltration flow was observed during natural rainfall events and during artificial infiltration experiments. For a better understanding of the behaviour of contaminants, experiments were conducted with cocktails of compounds of different reactivity (ammonium, strontium, atratone) and of non-reactive tracers (uranine, bromide, naphthionate), which represent different classes of pollutants. The experiment identified cation exchange reactions influencing the composition of the infiltrating water. These processes occurred under preferential flow conditions in macropores of the material. Measuring concentration changes under the controlled inflow of tracer experiments, the pollution potential was found to be high. Non-reactive tracers exhibited fast breakthrough and little sorption.

  5. Excavation damage zone tracer experiment in the floor of the room 415 test tunnel

    International Nuclear Information System (INIS)

    Frost, L.H.; Everitt, R.A.

    1997-03-01

    A 3.5-m-diameter test tunnel was constructed on the 420 Level of AECL's Underground Research Laboratory using a mechanical excavation technique. The orientation of the tunnel was chosen to maximize the stress ratio in the plane perpendicular to the tunnel axis in order to promote and study stress-induced excavation damage. The resulting excavation damage zone (EDZ) is characterized by a distinct breakout notch in both the floor and roof of the tunnel. In the floor of the tunnel, the main flow pathway within the EDZ is within a zone of intense grain-size fracturing (process zone) located at the tip of the breakout notch; virtually no flow occurs outside this region. A tracer experiment was performed within the EDZ in the floor of the tunnel to characterize the solute transport properties (permeability, transport porosity and dispersivity) within the process zone, as well as to develop and demonstrate methods for determining the transport properties within EDZs of underground tunnels. The experiment was performed as a constant head test by continuously injecting a constant concentration of iodide tracer into a region of the process zone, and by monitoring tracer breakthrough from the zone at a distance 1.5 m away. An equivalent-porous-media approach was taken in analysing fluid flow and solute transport through the process zone. Based on mass flux calculations, the hydraulic conductivity and transport porosity of the process zone are estimated to be 7.4 x 10 -7 m/s and 2.7 % respectively. Based on an analytic solution that represents tracer transport within the process zone as one-dimensional advective diffusive transport in a finite homogeneous porous medium, the longitudinal dispersivity and transport porosity of the zone are estimated to be 0.60 m and 3.3 % respectively. The transport porosity values estimated by both the mass flux and analytic calculations compare quite well. (author)

  6. Characterization of two-phase flow regimes in horizontal tubes using 81mKr tracer experiments.

    Science.gov (United States)

    Oriol, Jean; Leclerc, Jean Pierre; Berne, Philippe; Gousseau, Georges; Jallut, Christian; Tochon, Patrice; Clement, Patrice

    2008-10-01

    The diagnosis of heat exchangers on duty with respect to flow mal-distributions needs the development of non-intrusive inlet-outlet experimental techniques in order to perform an online fault diagnosis. Tracer experiments are an example of such techniques. They can be applied to mono-phase heat exchangers but also to multi-phase ones. In this case, the tracer experiments are more difficult to perform. In order to check for the capabilities of tracer experiments to be used for the flow mal-distribution diagnosis in the case of multi-phase heat exchangers, we present here a preliminary study on the simplest possible system: two-phase flows in a horizontal tube. (81m)Kr is used as gas tracer and properly collimated NaI (TI) crystal scintillators as detectors. The specific shape of the tracer response allows two-phase flow regimes to be characterized. Signal analysis allows the estimation of the gas phase real average velocity and consequently of the liquid phase real average velocity as well as of the volumetric void fraction. These results are compared successfully to those obtained with liquid phase tracer experiments previously presented by Oriol et al. 2007. Characterization of the two-phase flow regimes and liquid dispersion in horizontal and vertical tubes using coloured tracer and no intrusive optical detector. Chem. Eng. Sci. 63(1), 24-34, as well as to those given by correlations from literature.

  7. Characterization of two-phase flow regimes in horizontal tubes using 81mKr tracer experiments

    International Nuclear Information System (INIS)

    Oriol, Jean; Leclerc, Jean Pierre; Berne, Philippe; Gousseau, Georges; Jallut, Christian; Tochon, Patrice; Clement, Patrice

    2008-01-01

    The diagnosis of heat exchangers on duty with respect to flow mal-distributions needs the development of non-intrusive inlet-outlet experimental techniques in order to perform an online fault diagnosis. Tracer experiments are an example of such techniques. They can be applied to mono-phase heat exchangers but also to multi-phase ones. In this case, the tracer experiments are more difficult to perform. In order to check for the capabilities of tracer experiments to be used for the flow mal-distribution diagnosis in the case of multi-phase heat exchangers, we present here a preliminary study on the simplest possible system: two-phase flows in a horizontal tube. 81m Kr is used as gas tracer and properly collimated NaI (TI) crystal scintillators as detectors. The specific shape of the tracer response allows two-phase flow regimes to be characterized. Signal analysis allows the estimation of the gas phase real average velocity and consequently of the liquid phase real average velocity as well as of the volumetric void fraction. These results are compared successfully to those obtained with liquid phase tracer experiments previously presented by Oriol et al. 2007. Characterization of the two-phase flow regimes and liquid dispersion in horizontal and vertical tubes using coloured tracer and no intrusive optical detector. Chem. Eng. Sci. 63(1), 24-34, as well as to those given by correlations from literature

  8. Characterization of two-phase flow regimes in horizontal tubes using {sup 81m}Kr tracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Oriol, Jean [LPAC, CEA Grenoble, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France); Leclerc, Jean Pierre [Laboratoire des Sciences du Genie Chimique (LSGC), Nancy-Universite, CNRS, BP 20451, F-54001 Nancy (France)], E-mail: leclerc@ensic.inpl-nancy.fr; Berne, Philippe; Gousseau, Georges [L2T, CEA Grenoble, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France); Jallut, Christian [Universite de Lyon, Universite Lyon 1, LAGEP, UMR CNRS 5007, ESCPE, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Tochon, Patrice; Clement, Patrice [GRETh, CEA Grenoble, 17, rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2008-10-15

    The diagnosis of heat exchangers on duty with respect to flow mal-distributions needs the development of non-intrusive inlet-outlet experimental techniques in order to perform an online fault diagnosis. Tracer experiments are an example of such techniques. They can be applied to mono-phase heat exchangers but also to multi-phase ones. In this case, the tracer experiments are more difficult to perform. In order to check for the capabilities of tracer experiments to be used for the flow mal-distribution diagnosis in the case of multi-phase heat exchangers, we present here a preliminary study on the simplest possible system: two-phase flows in a horizontal tube. {sup 81m}Kr is used as gas tracer and properly collimated NaI (TI) crystal scintillators as detectors. The specific shape of the tracer response allows two-phase flow regimes to be characterized. Signal analysis allows the estimation of the gas phase real average velocity and consequently of the liquid phase real average velocity as well as of the volumetric void fraction. These results are compared successfully to those obtained with liquid phase tracer experiments previously presented by Oriol et al. 2007. Characterization of the two-phase flow regimes and liquid dispersion in horizontal and vertical tubes using coloured tracer and no intrusive optical detector. Chem. Eng. Sci. 63(1), 24-34, as well as to those given by correlations from literature.

  9. Field tracer transport experiments at the site of Canada's underground research laboratory

    International Nuclear Information System (INIS)

    Frost, L.H.; Davison, C.C.; Vandergraaf, T.T.; Scheier, N.W.; Kozak, E.T.

    1997-01-01

    To gain a better understanding of the processes affecting solute transport in fractured crystalline rock, groundwater tracer experiments are being performed within natural fracture domains and excavation damage zones at various scales at the site of AECL's Underground Research Laboratory (URL). The main objective of these experiments is to develop and demonstrate methods for characterizing the solute transport properties within fractured crystalline rock. Estimates of these properties are in turn being used in AECL's conceptual and numerical models of groundwater flow and solute transport through the geosphere surrounding a nuclear fuel waste disposal vault in plutonic rock of the Canadian Shield. (author)

  10. On interpreting studies of tracer transport by deep cumulus convection and its effects on atmospheric chemistry

    Directory of Open Access Journals (Sweden)

    M. G. Lawrence

    2008-10-01

    Full Text Available Global chemistry-transport models (CTMs and chemistry-GCMs (CGCMs generally simulate vertical tracer transport by deep convection separately from the advective transport by the mean winds, even though a component of the mean transport, for instance in the Hadley and Walker cells, occurs in deep convective updrafts. This split treatment of vertical transport has various implications for CTM simulations. In particular, it has led to a misinterpretation of several sensitivity simulations in previous studies in which the parameterized convective transport of one or more tracers is neglected. We describe this issue in terms of simulated fluxes and fractions of these fluxes representing various physical and non-physical processes. We then show that there is a significant overlap between the convective and large-scale mean advective vertical air mass fluxes in the CTM MATCH, and discuss the implications which this has for interpreting previous and future sensitivity simulations, as well as briefly noting other related implications such as numerical diffusion.

  11. Project ABLE: (Atmospheric Balloonborne Lidar Experiment)

    Science.gov (United States)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Sheehan, W. H.

    1985-03-01

    Project ABLE (Atmospheric Balloonborne Lidar Experiment) is part of the A.F. Geophysics Laboratory's continuing interest in developing techniques for making remote measurements of atmospheric quantities such as density, pressure, temperatures, and wind motions. The system consists of a balloonborne lidar payload designed to measure neutral molecular density as a function of altitude from ground level to 70 km. The lidar provides backscatter data at the doubled and tripled frequencies of a Nd:YAG laser, which will assist in the separation of the molecular and aerosol contributions and subsequent determination of molecular and aerosol contributions and subsequent determination of molecular density vs altitude. The object of this contract was to fabricate and operate in a field test a balloonborne lidar experiment capable of performing nighttime atmospheric density measurements up to 70 km altitude with a resolution of 150 meters. The payload included a frequency-doubled and -tripled Nd:YAG laser with outputs at 355 and 532 nm; a telescoped receiver with PMT detectors; a command-controlled optical pointing system; and support system, including thermal control, telmetry, command, and power. Successful backscatter measurements were made during field operations which included a balloon launch from Roswell, NM and a flight over the White Sands Missile Range.

  12. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    International Nuclear Information System (INIS)

    Winberg, A.; Andersson, Peter; Hermanson, Jan; Byegaard, Johan

    2000-03-01

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory ( 22 Na + 47 Ca 2+ ≅ 85 Sr 2+ 86 Rb + ≅ 133 Ba 2+ The field tracer tests, using essentially the same cocktail of sorbing tracers as in the laboratory, were found to show the same relative sorbtivity as seen in the laboratory. A test using 137 Cs showed that after termination of the test, some 63% of the injected activity remained sorbed in the rock. The interpretation of the in situ tests with sorbing tracers was performed using the LaSAR approach, developed as a part of the TRUE project. In this approach the studied flow path is viewed as a part of an open fracture. Key processes are spatially variable advection and mass transfer. The evaluation shows that laboratory diffusion data are not representative for in situ conditions, and that a close fit between field and modelled breakthrough is obtained only when a parameter group which includes diffusion is enhanced with a factor varying between 32-50 for all tracers and experiments (except for Cs) and 137 for Cs. Our interpretation is that the enhancement is mainly due to higher diffusivity/porosity and higher sorption in the part of the altered rim zone of the feature which is accessible over the time scales

  13. Development of soft x-ray tracer diagnostics for hohlraum experiments

    International Nuclear Information System (INIS)

    MacFarlane, J.J.; Cohen, D.H.; Wang, P.; Peterson, R.R.; Moses, G.A.

    1998-04-01

    The purpose of this report is to summarize work performed by the University of Wisconsin during fiscal year 1996 under the NLUF contract DE-FG-96SF21015. This contract involved the development of soft x-ray spectral diagnostics from tracer layers in hohlraum witness plates. This effort was originally intended to be focused on OMEGA experiments, but the experiments were changed to NOVA because initial indirect drive shots had not yet been performed on the OMEGA upgrade. Data were collected in a series of experiments between January 1997 and October 1997. Experiments were delayed somewhat due to bringing up the Hettrick spectrometer on the NOVA target chamber. The tasks related to the planning, carrying out, and modeling of the experiments are outlined in Table 1.1 and detailed in the remainder of this report

  14. Atmospheric tracer study of the emissions from the University of Michigan Cyclotron/PET Facility

    International Nuclear Information System (INIS)

    Scofield, P.A.

    1986-01-01

    The University of Michigan (U of M) Cyclotron/Positron Emission Tomography (PET) facility consists of a cyclotron (Model CS-30, The Cyclotron Corporation), radiochemistry laboratory, and Pet scanner. Accelerator-produced radioactive materials, such as, carbon-11 and oxygen-15 are typically emitted from the Cyclotron/PET facility through short stacks located on the roof. This project studied the dispersion of emissions from the facility within the medical complex. To achieve this purpose, the research project had three phases: a physical modeling study; a preliminary field smoke release study; and, a field study using a tracer gas to simulate emission dispersion from the U of M Cyclotron/PET facility vault stack. The objective was to determine normalized concentrations, under selected wind directions and speeds, for use in establishing radionuclide concentrations at the air intakes of the Cyclotron/PET facility and surrounding buildings and at selected ground-level locations

  15. Present status and future prospects of the atmospheric neutrino experiments

    International Nuclear Information System (INIS)

    Kajita, Takaaki

    2003-01-01

    During the last several years, the understanding of the neutrino masses and mixings has been improved significantly. In this paper, we discuss neutrino oscillation studies in atmospheric neutrino experiments. Prospects of future atmospheric neutrino experiments are also discussed

  16. A concept for limiting the number of radioactive tracer experiments in a factory plant

    International Nuclear Information System (INIS)

    Monchy, A.R. de

    1980-01-01

    There are currently no restrictions regarding the quantities of radioactive material stored, used or discharged in factories where radioactive tracer experiments are performed. This article describes a concept for such restrictions, based on two criteria - 1) a system of standards for the absorption of the contamination by either water or air, dependent on the half life of the nuclides used and 2) a summation procedure of the activities of the nuclides used, the activities being weighed by the toxicity and chance of spreading of each nuclide. (C.F.)

  17. Characterization of reactive tracers for C-wells field experiments 1: Electrostatic sorption mechanism, lithium

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Essington, E.H.; Newman, B.D.

    1989-11-01

    Lithium (Li + ) was introduced as lithium bromide (LiBr), as a retarded tracer for experiments in the C-wells complex at Yucca Mountain, Nevada Test Site, Nevada. The objective was to evaluate the potential of lithium to sorb predominately by physical forces. lithium was selected as a candidate tracer on the basis of high solubility, good chemical and biological stability, and relatively low sorptivity; lack of bioaccumulation and exclusion as a priority pollutant in pertinent federal environmental regulations; good analytical detectability and low natural background concentrations; and a low cost Laboratory experiments were performed with suspensions of Prow Pass cuttings from drill hole UE-25p number-sign 1 at depths between 549 and 594 m in J-13 water at a pH of approximately 8 and in the temperature range of 25 degree C to 45 degree C. Batch equilibrium and kinetics experiments were performed; estimated thermodynamic constants, relative behavior between adsorption and desorption, and potentiometric studies provided information to infer the physical nature of lithium sorption

  18. Preliminary - discrete fracture network modelling of tracer migration experiments at the SCV site

    International Nuclear Information System (INIS)

    Dershowitz, W.S.; Wallmann, P.; Geier, J.E.; Lee, G.

    1991-09-01

    This report describes a numerical modelling study of solute transport within the Site Characterization and Validation (SCV) block at the Stripa site. The study was carried out with the FracMan/MAFIC package, utilizing statistics from stages 3 and 4 of the Stripa phase 3 Site Characterization and Validation project. Simulations were carried out to calibrate fracture solute transport properties against observations in the first stage of saline injection radar experiments. These results were then used to predict the performance of planned tracer experiments, using both particle tracking network solute transport, and pathways analysis approaches. Simulations were also carried out to predict results of the second stage of saline injection radar experiments. (au) (34 refs.)

  19. Evaluation of the moisture sources in two extreme landfalling atmospheric river events using an Eulerian WRF tracers tool

    Science.gov (United States)

    Eiras-Barca, Jorge; Dominguez, Francina; Hu, Huancui; Garaboa-Paz, Daniel; Miguez-Macho, Gonzalo

    2017-12-01

    A new 3-D tracer tool is coupled to the WRF model to analyze the origin of the moisture in two extreme atmospheric river (AR) events: the so-called Great Coastal Gale of 2007 in the Pacific Ocean and the Great Storm of 1987 in the North Atlantic. Results show that between 80 and 90 % of moisture advected by the ARs, and a high percentage of the total precipitation produced by the systems have a tropical origin. The tropical contribution to precipitation is in general above 50 % and largely exceeds this value in the most affected areas. Local convergence transport is responsible for the remaining moisture and precipitation. The ratio of tropical moisture to total moisture is maximized as the cold front arrives on land. Vertical cross sections of the moisture content suggest that the maximum in tropical humidity does not necessarily coincide with the low-level jet (LLJ) of the extratropical cyclone. Instead, the amount of tropical humidity is maximized in the lowest atmospheric level in southern latitudes and can be located above, below or ahead of the LLJ in northern latitudes in both analyzed cases.

  20. Evaluation of the moisture sources in two extreme landfalling atmospheric river events using an Eulerian WRF tracers tool

    Directory of Open Access Journals (Sweden)

    J. Eiras-Barca

    2017-12-01

    Full Text Available A new 3-D tracer tool is coupled to the WRF model to analyze the origin of the moisture in two extreme atmospheric river (AR events: the so-called Great Coastal Gale of 2007 in the Pacific Ocean and the Great Storm of 1987 in the North Atlantic. Results show that between 80 and 90 % of moisture advected by the ARs, and a high percentage of the total precipitation produced by the systems have a tropical origin. The tropical contribution to precipitation is in general above 50 % and largely exceeds this value in the most affected areas. Local convergence transport is responsible for the remaining moisture and precipitation. The ratio of tropical moisture to total moisture is maximized as the cold front arrives on land. Vertical cross sections of the moisture content suggest that the maximum in tropical humidity does not necessarily coincide with the low-level jet (LLJ of the extratropical cyclone. Instead, the amount of tropical humidity is maximized in the lowest atmospheric level in southern latitudes and can be located above, below or ahead of the LLJ in northern latitudes in both analyzed cases.

  1. The Social Network of Tracer Variations and O(100) Uncertain Photochemical Parameters in the Community Atmosphere Model

    Science.gov (United States)

    Lucas, D. D.; Labute, M.; Chowdhary, K.; Debusschere, B.; Cameron-Smith, P. J.

    2014-12-01

    Simulating the atmospheric cycles of ozone, methane, and other radiatively important trace gases in global climate models is computationally demanding and requires the use of 100's of photochemical parameters with uncertain values. Quantitative analysis of the effects of these uncertainties on tracer distributions, radiative forcing, and other model responses is hindered by the "curse of dimensionality." We describe efforts to overcome this curse using ensemble simulations and advanced statistical methods. Uncertainties from 95 photochemical parameters in the trop-MOZART scheme were sampled using a Monte Carlo method and propagated through 10,000 simulations of the single column version of the Community Atmosphere Model (CAM). The variance of the ensemble was represented as a network with nodes and edges, and the topology and connections in the network were analyzed using lasso regression, Bayesian compressive sensing, and centrality measures from the field of social network theory. Despite the limited sample size for this high dimensional problem, our methods determined the key sources of variation and co-variation in the ensemble and identified important clusters in the network topology. Our results can be used to better understand the flow of photochemical uncertainty in simulations using CAM and other climate models. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and supported by the DOE Office of Science through the Scientific Discovery Through Advanced Computing (SciDAC).

  2. Atmospheric modeling to assess wind dependence in tracer dilution method measurements of landfill methane emissions.

    Science.gov (United States)

    Taylor, Diane M; Chow, Fotini K; Delkash, Madjid; Imhoff, Paul T

    2018-03-01

    The short-term temporal variability of landfill methane emissions is not well understood due to uncertainty in measurement methods. Significant variability is seen over short-term measurement campaigns with the tracer dilution method (TDM), but this variability may be due in part to measurement error rather than fluctuations in the actual landfill emissions. In this study, landfill methane emissions and TDM-measured emissions are simulated over a real landfill in Delaware, USA using the Weather Research and Forecasting model (WRF) for two emissions scenarios. In the steady emissions scenario, a constant landfill emissions rate is prescribed at each model grid point on the surface of the landfill. In the unsteady emissions scenario, emissions are calculated at each time step as a function of the local surface wind speed, resulting in variable emissions over each 1.5-h measurement period. The simulation output is used to assess the standard deviation and percent error of the TDM-measured emissions. Eight measurement periods are simulated over two different days to look at different conditions. Results show that standard deviation of the TDM- measured emissions does not increase significantly from the steady emissions simulations to the unsteady emissions scenarios, indicating that the TDM may have inherent errors in its prediction of emissions fluctuations. Results also show that TDM error does not increase significantly from the steady to the unsteady emissions simulations. This indicates that introducing variability to the landfill emissions does not increase errors in the TDM at this site. Across all simulations, TDM errors range from -15% to 43%, consistent with the range of errors seen in previous TDM studies. Simulations indicate diurnal variations of methane emissions when wind effects are significant, which may be important when developing daily and annual emissions estimates from limited field data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Model study of atmospheric transport using carbon 14 and strontium 90 as inert tracers

    Science.gov (United States)

    Kinnison, D. E.; Johnston, H. S.; Wuebbles, D. J.

    1994-10-01

    The observed excess carbon 14 in the atmosphere from 1963 to 1970 provides unique, but limited, data up to an altitude of about 35 km for testing the air motions calculated by 11 multidimensional atmospheric models. Strontium 90 measurements in the atmosphere from 1964 to mid-1967 provide data that have more latitude coverage than those of carbon 14 and are useful for testing combined models of air motions and aerosol settling. Model calculations for carbon 14 begin at October 1963, 9 months after the conclusion of the nuclear bomb tests; the initial conditions for the calculations are derived by three methods, each of which agrees fairly well with measured carbon 14 in October 1963 and each of which has widely different values in regions of the stratosphere where there were no carbon 14 measurements. The model results are compared to the stratospheric measurements, not as if the observed data were absolute standards, but in an effort to obtain new insight about the models and about the atmosphere. The measured carbon 14 vertical profiles at 31°N are qualitatively different from all of the models; the measured vertical profiles show a maximum mixing ratio in the altitude range of 20 to 25 km from October 1963 through July 1966, but all modeled profiles show mixing ratio maxima that increase in altitude from 20 km in October 1963 to greater than 40 km by April 1966. Both carbon 14 and strontium 90 data indicate that the models differ substantially among themselves with respect to stratosphere-troposphere exchange rate, but the modeled carbon 14 stratospheric residence times indicate that differences among the models are small with respect to transport rate between the middle stratosphere and the lower stratosphere. Strontium 90 data indicate that aerosol settling is important up to at least 35 km altitude. Relative to the measurements, about three quarters of the models transport carbon 14 from the lower stratosphere to the troposphere too rapidly, and all models

  4. Spanish Moss as an atmospheric tracer for trace elements from fossil fuel burning power plants

    International Nuclear Information System (INIS)

    James, W.D.; Padaki, P.; McWilliams, E.L.

    1991-01-01

    Samples of Spanish Moss (Tillandsia usneoides) were analyzed by neutron activation analysis (NAA), inductively coupled argon plasma emission spectrometry (ICP), and x-ray fluorescence analysis (XRF) for trace elements as atmospheric environmental monitors. In particular, certain elements thought likely to be contributed to the atmosphere by combustion of fossil fuels were studied in samples collected along two transects, an east/west transect from the Louisiana line west to Dallas and a north/south transect from the Limestone electric Generating Station north to Dallas. Plants were sampled during peak electric generating periods in the summer, as well as following planned outages during the winter months. Se, As and several other volatile species known to concentrate in fly ash particles which are likely to escape power plant collection devices were shown to correlate with downwind directions of plant plumes. Attempts to determine levels of sulfur taken up by the plants which can be attributed to fossil fuel combustion through the use of these marker elements have also be made

  5. "Submesoscale Soup" Vorticity and Tracer Statistics During the Lateral Mixing Experiment

    Science.gov (United States)

    Shcherbina, A.; D'Asaro, E. A.; Lee, C. M.; Molemaker, J.; McWilliams, J. C.

    2012-12-01

    A detailed view of upper-ocean velocity, vorticity, and tracer statistics was obtained by a unique synchronized two-vessel survey in the North Atlantic in winter 2012. In winter, North Atlantic Mode water region south of the Gulf Stream is filled with an energetic, homogeneous, and well-developed submesoscale turbulence field - the "submesoscale soup". Turbulence in the soup is produced by frontogenesis and the surface layer instability of mesoscale eddy flows in the vicinity of the Gulf Stream. This region is a convenient representation of the inertial range of the geophysical turbulence forward cascade spanning scales of o(1-100km). During the Lateral Mixing Experiment in February-March 2012, R/Vs Atlantis and Knorr were run on parallel tracks 1 km apart for 500 km in the submesoscale soup region. Synchronous ADCP sampling provided the first in-situ estimates of full 3-D vorticity and divergence without the usual mix of spatial and temporal aliasing. Tracer distributions were also simultaneously sampled by both vessels using the underway and towed instrumentation. Observed vorticity distribution in the mixed layer was markedly asymmetric, with sparse strands of strong anticyclonic vorticity embedded in a weak, predominantly cyclonic background. While the mean vorticity was close to zero, distribution skewness exceeded 2. These observations confirm theoretical and numerical model predictions for an active submesoscale turbulence field. Submesoscale vorticity spectra also agreed well with the model prediction.

  6. In situ gaseous tracer diffusion experiments and predictive modeling at the Greater Confinement Disposal Test

    International Nuclear Information System (INIS)

    Olson, M.C.

    1985-07-01

    The Greater Confinement Disposal Test (GCDT) at the Nevada Test Site is a research project investigating the feasibility of augered shaft disposal of low-level radioactive waste considered unsuitable for shallow land burial. The GCDT contains environmentally mobile and high-specific-activity sources. Research is focused on providing a set of analytically derived hydrogeologic parameters and an empirical database for application in a multiphase, two-dimensional, transient, predictive performance model. Potential contaminant transport processes at the GCDT are identified and their level of significance is detailed. Nonisothermal gaseous diffusion through alluvial sediments is considered the primary waste migration process. Volatile organic tracers are released in the subsurface and their migration is monitored in situ to determine media effective diffusion coefficients, tortuosity, and sorption-corrected porosity terms. The theoretical basis for volatile tracer experiments is presented. Treatment of thermal and liquid flow components is discussed, as is the basis for eliminating several negligible transport processes. Interpretive techniques include correlation, power spectra, and least squares analysis, a graphical analytical solution, and inverse numerical modeling. Model design and application to the GCDT are discussed. GCDT structural, analytical, and computer facilities are detailed. The status of the current research program is reviewed, and temperature and soil moisture profiles are presented along with results of operational tests on the analytical system. 72 refs., 39 figs., 2 tabs

  7. Use of lead-210 and polonium-210 as tracers of atmospheric processes

    International Nuclear Information System (INIS)

    Nevissi, A.; Schell, W.R.

    1980-01-01

    The inputs of 210 Pb and 210 Po have been measured in two marine environments to trace atmospheric processes. Precipitation and dry fallout samples were collected monthly at Seattle, Wash., over a period of 4 years, and air filter samples were collected biweekly at the ground level on Amchitka Island, Alaska, over a period of 3 years. The results for both stations show that 210 Pb undergoes seasonal variations in surface deposition with minimum values in relatively dry months of summer and maximum values in the fall or winter. The seasonal variations of 210 Pb are attributed to several factors including: 210 Pb content of the air masses involved, changes in the meteorological conditions, and local input of 210 Pb as a result of radon exhalation and soil resuspension

  8. Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers.

    Science.gov (United States)

    Wildemeersch, S; Jamin, P; Orban, P; Hermans, T; Klepikova, M; Nguyen, F; Brouyère, S; Dassargues, A

    2014-11-15

    Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54MJ/m(3)/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for

  9. Levoglucosan, a tracer for cellulose in biomass burning and atmospheric particles

    Science.gov (United States)

    Simoneit, B. R. T.; Schauer, J. J.; Nolte, C. G.; Oros, D. R.; Elias, V. O.; Fraser, M. P.; Rogge, W. F.; Cass, G. R.

    The major organic components of smoke particles from biomass burning are monosaccharide derivatives from the breakdown of cellulose, accompanied by generally lesser amounts of straight-chain, aliphatic and oxygenated compounds and terpenoids from vegetation waxes, resins/gums, and other biopolymers. Levoglucosan and the related degradation products from cellulose can be utilized as specific and general indicator compounds for the presence of emissions from biomass burning in samples of atmospheric fine particulate matter. This enables the potential tracking of such emissions on a global basis. There are other compounds (e.g. amyrones, friedelin, dehydroabietic acid, and thermal derivatives from terpenoids and from lignin—syringaldehyde, vanillin, syringic acid, vanillic acid), which are additional key indicators in smoke from burning of biomass specific to the type of biomass fuel. The monosaccharide derivatives (e.g. levoglucosan) are proposed as specific indicators for cellulose in biomass burning emissions. Levoglucosan is emitted at such high concentrations that it can be detected at considerable distances from the original combustion source.

  10. NAMMA LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Lidar Atmospheric Sensing Experiment (LASE) system using the DIAL (Differential Absorption Lidar) system was operated during the NASA African Monsoon...

  11. The use of synthetic colloids in tracer transport experiments in saturated rock fractures

    International Nuclear Information System (INIS)

    Reimus, P.W.

    1995-08-01

    Studies of groundwater flow and contaminant transport in saturated, fractured geologic media are of great interest to researchers studying the potential long-term storage of hazardous wastes in or near such media. A popular technique for conducting such studies is to introduce tracers having different chemical and physical properties into a system and then observe the tracers at one or more downstream locations, inferring flow and transport mechanisms from the breakthrough characteristics of the different tracers. Many tracer studies have been conducted in saturated, fractured media to help develop and/or refine models capable of predicting contaminant transport over large scales in such media

  12. The fluorescent tracer experiment on Holiday Beach near Mugu Canyon, Southern California

    Science.gov (United States)

    Kinsman, Nicole; Xu, J. P.

    2012-01-01

    After revisiting sand tracer techniques originally developed in the 1960s, a range of fluorescent coating formulations were tested in the laboratory. Explicit steps are presented for the preparation of the formulation evaluated to have superior attributes, a thermoplastic pigment/dye in a colloidal mixture with a vinyl chloride/vinyl acetate copolymer. In September 2010, 0.59 cubic meters of fluorescent tracer material was injected into the littoral zone about 4 kilometers upcoast of Mugu submarine canyon in California. The movement of tracer was monitored in three dimensions over the course of 4 days using manual and automated techniques. Detailed observations of the tracer's behavior in the coastal zone indicate that this tracer successfully mimicked the native beach sand and similar methods could be used to validate models of tracer movement in this type of environment. Recommendations including how to time successful tracer studies and how to scale the field of view of automated camera systems are presented along with the advantages and disadvantages of the described tracer methodology.

  13. Guiding principles for estimation of whole-body synthesis rates by tracer experiments

    International Nuclear Information System (INIS)

    Krawielitzki, K.; Schadereit, R.; Wuensche, J.

    1989-01-01

    Methodical recommendations are suggested-predominantly for laboratory and small animals (rats and young chickens)-for the determination of parameters of the protein metabolism of the whole body after single dosis of a mixture of 15 N-labelled amino acids by means of the determination of the temporal course of cumulative 15 N excretion in urine and the assessment of the tracer kinetic data in a compartment model. These recommendations are to make it possible to carry out purposefully such experiments under comparable conditions. The advantages of this method are: (1) the non-invasive character of the method; (2) the possibility of repeating the experiment with the same animal; (3) the adaptability to other methods of investigation (e.g. measuring energy metabolism); (4) the relatively low expenditure of labour and requirement of test animals; (5) the relatively good reproducibility of the method. Thus this method is a good supplement to the flooding and permanent infusion methods and should be used wherever the determination of parameters of the protein metabolism of the total body is sufficient. (author)

  14. Experiences made with tritium-containing water used as tracer in laboratory experiments with fluvioglacial gravels

    International Nuclear Information System (INIS)

    Klotz, D.; Rauert, W.

    1982-01-01

    Batch tests performed on 11 different Bavarian fluvioglacial gravels led to tritium distribution coefficients, which deviated not or only insignificantly from zero within the range of experimental accuracy applied to routine testings. The result of nine flow experiments in a gravelfilled column was a mean retardation factor of 1.01 +- 0.01. These experiments thus showed - as it had been expected - that 3 HHO is not significantly delayed with regard to the flow or movement of the water. (orig.) [de

  15. Effects from influent boundary conditions on tracer migration and spatial variability features in intermediate-scale experiments

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Springer, E.P.

    1987-04-01

    In previous unsaturated transport studies at Los Alamos dispersion coefficients were estimated to be higher close to the tracer source than at greater distances from the source. Injection of tracers through discrete influent outlets could have accounted for those higher dispersions. Also, a lack of conservation of mass of the tracers was observed and suspected to be due to spatial variability in transport. In the present study experiments were performed under uniform influent (ponded) conditions in which breakthrough of tracers was monitored at four locations at each of four depths. All other conditions were similar to those of the unsaturated transport experiments. A comparison of results from these two sets of experiments indicates differences in the parameter estimates. Estimates were made for the dispersion coefficient and the retardation factor by the one-dimensional steady flow computer code, CFITIM. Estimates were also made for mass and for velocity and the dispersion coefficient by the method of moments. The dispersion coefficient decreased with depth under discrete influent application and increased with depth under ponded influent application. Retardation was predicted better under the discrete influent application than under ponded influent application. Differences in breakthroughs and in estimated parameters among locations at the same depth were observed under ponded influent application. Those differences indicate that there is a lack of conservation of mass as well as significant spatial variability across the experimental domain. 14 refs., 9 figs., 8 tabs

  16. Predicted fate of tritium residuum from groundwater tracer experiments in the Amargosa Desert, southern Nevada

    International Nuclear Information System (INIS)

    Brikowski, T.

    1993-07-01

    Analytic solutions are used in this study to evaluate potential groundwater transport of tritium used in goundwater tracer tests southwest of the Nevada Test Site. Possible transport from this site is of interest because initial radionuclide concentrations were high and the site is close to goundwater discharge points (12 km). Anecdotal evidence indicates that 90 percent of these tracers were removed by pumping at the completion of the tests; this study examines the probable transport of the tracers with and without the removal. Classical dispersive transport analytic solutions are used, treating the tracer test as a point slug injection. Input parameters for the solutions were measured at the site, and consideration of parameter uncertainty is incorporated in the results. With removal of the tracer, the maximum expected region with above-Safe Drinking Water Act (40 CFR 121) concentrations of tritium extends 5 km from the injection point, and does not reach any sites of public access. Detectable tritium from the tests is likely to have reached the Ash Meadows fault zone, but flow along the fault probably diluted the tracer to below detection limits before arrival at springs along the fault. Arrival at the springs would have occurred 20 to 25 years after the tests. Without removal of the tracer, the solutions indicate that tritium concentrations just above Safe Drinking Water Act standards would have reached the Ash Meadows fault zone. In this case, detectable tritium might have been found in Devil's Hole or Longstreet Spring, the nearest points of possible public exposure

  17. The evaluation of data from the MACRO tracer experiment. The report for Japan Nuclear Cycle Development Institute

    International Nuclear Information System (INIS)

    Watari, Shingo

    1999-12-01

    On understanding the radionuclide transport in Natural Barrier in radioactive waste isolation research, the macroscopic dispersion in heterogeneous permeability field in the underground rock is regarded as an important process. Therefore, Japan Nuclear Cycle Development Institute (JNC) developed the MACRO experiment with an artificial heterogeneous permeability field and has been conducted lots of tracer experiments. To estimate the effect of characteristics of field on the macroscopic dispersion using data from those tracer experiments, the evaluation of dispersion coefficient is required. In this report, the macroscopic dispersion coefficients were evaluated for the results of the tracer experiments using the MACRO facility with a single well. The coefficients for the experiments of 18 cases were evaluated by the fitting of analytical solution to the breakthrough curve measured in the well. In the evaluations, the correction of data measured in the experiments and of the accuracy in the evaluation were considered. The conclusions are as follows. The macroscopic dispersion coefficients for 18 cases were evaluated using Least Square Method by fitting the analytical evaluation to the result of experiment. Consequently, the coefficients for 7 cases were evaluated with not enough accurate fitting results. Therefore, another evaluations for those 7 cases were required to be with more accuracy. Then, those coefficients were evaluated with enough accuracy. It was verified that the macroscopic dispersion coefficient tend to be increased with increase of the average radius of tracer front. In some cases, however, the trend was not verified because of the limit of accuracy for data measured in the experiment and for the evaluation method of the coefficient. It was found that the macroscopic dispersion coefficients evaluated for the cases with heterogeneous permeability field type B tend to be higher than those with heterogeneous permeability field type A. (author)

  18. Quantifying Reaeration Rates in Alpine Streams Using Deliberate Gas Tracer Experiments

    Directory of Open Access Journals (Sweden)

    Andrew Benson

    2014-04-01

    Full Text Available Gas exchange across the air-water interface is a critical process that maintains adequate dissolved oxygen (DO in the water column to support life. Oxygen reaeration rates can be accurately measured using deliberate gas tracers, like sulfur hexafluoride (SF6 or xenon (Xe. Two continuous release experiments were conducted in different creeks in the Sierra Nevada of California: Sagehen Creek in September, 2009, using SF6 and Martis Creek in August, 2012, using both SF6 and Xe. Measuring gas loss along the creek, which was approximated with the one-dimensional advection-dispersion equation, allows for the estimation of the SF6 or Xe reaeration coefficient (KSF6, KXe, which is converted to DO reaeration (KDO or K2 using Schmidt numbers. Mean KSF6 for upper and lower Sagehen and Martis Creeks were, respectively, 34 day−1, 37 day−1 and 33 day−1, with corresponding KDOs of 61 day−1, 66 day−1 and 47 day−1. In Martis Creek, KXe was slightly higher (21% than KSF6, but the calculated KDO from SF6 agreed with the calculated KDO from Xe within about 15%; this difference may be due to bubble-enhanced gas transfer. Established empirical equations of KDO using stream characteristics did a poor job predicting KDO for both creeks.

  19. Multitracing Experiment With Solved and Particulate Tracers In An Unsaturated Field Soil

    Science.gov (United States)

    Burkhardt, M.; Kasteel, R.; Vereecken, H.

    Solute movement and colloid migration follow preferential flow paths in structured soils at the field scale. The use of microsphreres is a possible option to mimic colloid transport through the vadose zone into the groundwater. We present results of multi- tracing experiments conducted in an Orthic Luvisol using bromide (Br-), the reactive dye tracer Brilliant Blue (BB) and microspheres. The fluorescent microspheres (1 and 10 µm in diameter) were functionalized with a negative surface charge. Eight field plots (about 2 m2) were irrigated with 10 mm and 40 mm during 6 h. Four field plots were sampled directly after the irrgation, the others were exposed for 90 days to natural wheather conditions. Photographs of horizontal cross-sections and disturbed soil sam- ples were taken every 5 to 10 cm down to a depth of 160 cm. Image analysis was used to derive concentration distributions of BB using a calibration relationship between concentration and color spectra. The microspheres were quantified after desorption of the soil samples by fluorescent microscopy and image analysis. We used moment analysis to characterize transport phenomena. We found that transport through the soil matrix was affected by sorption, but all of the applied compounds were transported through preferential flow paths (earthworm burrows) down to a depth of 160 cm irre- spective of their chemical properties. Furthermore, this study shows that microspheres can be used to mimic colloid facilitated transport under unsaturated conditions in a field soil.

  20. Metabolite-balancing techniques vs. 13C tracer experiments to determine metabolic fluxes in hybridoma cells.

    Science.gov (United States)

    Bonarius, H P; Timmerarends, B; de Gooijer, C D; Tramper, J

    The estimation of intracellular fluxes of mammalian cells using only mass balances of the relevant metabolites is not possible because the set of linear equations defined by these mass balances is underdetermined. In order to quantify fluxes in cyclic pathways the mass balance equations can be complemented with several constraints: (1) the mass balances of co-metabolites, such as ATP or NAD(P)H, (2) linear objective functions, (3) flux data obtained by isotopic-tracer experiments. Here, these three methods are compared for the analysis of fluxes in the primary metabolism of continuously cultured hybridoma cells. The significance of different theoretical constraints and different objective functions is discussed after comparing their resulting flux distributions to the fluxes determined using 13CO2 and 13C-lactate measurements of 1 - 13C-glucose-fed hybridoma cells. Metabolic fluxes estimated using the objective functions "maximize ATP" and "maximize NADH" are relatively similar to the experimentally determined fluxes. This is consistent with the observation that cancer cells, such as hybridomas, are metabolically hyperactive, and produce ATP and NADH regardless of the need for these cofactors. Copyright 1998 John Wiley & Sons, Inc.

  1. Plutonium and tracer particle resuspension: an overview of selected Battelle-Northwest experiments

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1977-01-01

    Plutonium resuspension at Rocky Flats was determined in July 1973, by measuring airborne plutonium as a function of sampling height and of wind speed. The maximum airborne plutonium-239 concentration was 3700 aCi/m 3 . The maximum plutonium-239 activity per gram of collected airborne soil was 50 pCi/g. Airborne plutonium concentrations were shown to increase as the sixth power of wind speed, but the data were very imprecise. In measurement of fallout resuspension caused by burning vegetation, the 137 Cs concentration in a forest fire smoke plume was 22 times the concentration in ambient air. Resuspension rates for a man walking across a tracer area on an asphalt surface ranged from 1 x 10 -5 to 7 x 10 -4 fraction of tracer resuspended/pass. For vehicular traffic driven on a tracer lane, resuspension rates from the asphalt surface ranged from 10 -4 to 10 -2 fraction resuspended/pass. When the vehicle was driven on the lane adjacent to the tracer lane, resuspension rates were smaller, ranging from 10 -5 to 10 -3 fraction resuspended/pass. Resuspension rates decreased when the tracer had been on the ground for several days. In comparison to the asphalt surface, vehicle-caused tracer resuspension rates from a cheat grass area were lower, ranging from 10 -5 to 10 -4 fraction resuspended/pass. Wind caused tracer resuspension rates were on the order of 10 -11 fraction resuspended/sec for nonrespirable particles. Resuspension rates for respirable particles increased as the 4.8th power of wind speed, ranging from 10 -11 to 10 -7 fraction resuspended/sec. In another study, airborne respirable soil concentrations measured as a function of wind speed increased as the 0.6 to 3.2 power of wind speed

  2. A Spectacular Experiment Exhibiting Atmospheric Pressure

    Science.gov (United States)

    Le Noxaïc, Armand

    2014-01-01

    The experiment described here is fairly easy to reproduce and dramatically shows the magnitude of ambient air pressure. Two circular plates of aluminum are applied one against the other. How do you make their separation very difficult? With only the help of an elastic band! You don't have to use a vacuum pump for this experiment.

  3. Popularity framework to process dataset tracers and its application on dynamic replica reduction in the ATLAS experiment

    CERN Document Server

    Molfetas, A; Tykhonov, A; Garonne, V; Campana, S; Lassnig, M; Barisits, M; Dimitrov, G; Viegas, F

    2011-01-01

    The ATLAS experiment's data management system is constantly tracing file movement operations that occur on the Worldwide LHC Computing Grid (WLCG). Due to the large scale of the WLCG, direct statistical analysis of the traces is impossible in real-time. Factors that contribute to the scalability problems include the capability for users to initiatiate on-demand queries, high dimensionality of tracer entries combined with very low cardinality parameters, the large size of the namespace as well as rapid rate of file transactions occuring on the Grid. These scalability issues are alleviated through the adoption of an incremental model that aggregates data for all combinations occurring in selected tracer fields on a daily basis. Using this model it is possible to query on-demand relevant statistics about system usage. We present an implementation of this popularity model in the experiment's distributed data management system, DQ2, and describe a direct application example of the popularity framework, an automate...

  4. Carbon-14 tracer studies in rat-liver perfusion experiments under conditions of gluconeogenesis from lactate and pyruvate

    International Nuclear Information System (INIS)

    Muellhofer, G.; Schwab, A.; Mueller, C.; Stetten, C. von; Gruber, E.

    1977-01-01

    The intracellular events in the metabolic pathway of gluconeogenesis from lactate and pyruvate in liver tissue were assumed to be understood. Nevertheless the results of several 14 C-tracer experiments gave rise to the postulation of still unknown intracellular interactions under this condition. A contribution was made to the solution of this problem by using different 14 C labelled tracers such as [1- 14 C]lactate or pyruvate and [2- 14 C]lactate or pyruvate. [ 14 C]bicarbonate and [1- 14 C]-octanoate in perfusion experiments with livers from rats under conditions of gluconeogenesis from lactate and pyruvate. The 14 C labelling patterns of intracellular metabolities such as malate, citrate, phosphoenolpyruvate, phosphoglycerate and newly synthesized glucose were analysed under different conditions. A comparison with values calculated by using metabolic models based on the generally accepted concepts of intracellular interactions showed some fundamental discrepancies which justify the postulation. (orig./MG) [de

  5. NAMMA LIDAR ATMOSPHERIC SENSING EXPERIMENT (LASE) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Lidar Atmospheric Sensing Experiment (LASE) dataset used the LASE system using the Differential Absorption Lidar (DIAL) system was operated during the NASA...

  6. Study on the metabolic characteristics of renal imaging agent 99mTc-PAHIDA with tracer experiment

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Wang Liuyi; Lun Mingyue

    1995-01-01

    Tracer experiment showed that 99m Tc-PAHIDA was distributed predominantly in kidney. The distribution in other tissue was in the following descending order: heart, gastrointestinal tract, liver, spleen, muscle, adipose tissue, testes, and brain. The smaller the intravenous dose, the lower the proportion of the drug was combined to plasma protein and the more the drug was distributed in kidney. Excretion of 99m Tc-PAHIDa via urine was rapid and was in its original form as shown by radiochromatography

  7. Possible Tau Appearance Experiment with Atmospheric Neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Stanev, Todor

    1999-12-27

    We suggest an experimental measurement that could detect the appearance of tau neutrinos due to {nu}{sub {mu}}{yields}{nu}{sub {tau}} oscillations of atmospheric neutrinos by measuring the energy spectra of neutrino induced showers. {tau} neutrinos deposit a large fraction of their energy in showers generated by {nu}{sub {tau}} charge current interactions and the subsequent {tau} -lepton decay. The appearance of {nu}{sub {tau}} will enhance the spectrum of neutrino induced showers in energy ranges corresponding to the neutrino oscillation parameters. A shower rate lower than the ''no oscillation'' prediction is an indication for {nu}{sub {mu}}{yields}{nu}{sub s} oscillations. (c) 1999 The American Physical Society.

  8. Tumoral tracers

    International Nuclear Information System (INIS)

    Camargo, E.E.

    1979-01-01

    Direct tumor tracers are subdivided in the following categories:metabolite tracers, antitumoral tracers, radioactive proteins and cations. Use of 67 Ga-citrate as a clinically important tumoral tracer is emphasized and gallium-67 whole-body scintigraphy is discussed in detail. (M.A.) [pt

  9. The Atmospheric Chemistry Experiment (ACE): Mission Overview

    Science.gov (United States)

    Bernath, P. F.; Boone, C.; Walker, K.; McLeod, S.; Nassar, R.

    2003-12-01

    The ACE mission goals are: (1) to measure and to understand the chemical and dynamical processes that control the distribution of ozone in the upper troposphere and stratosphere, with a particular emphasis on the Arctic region; (2) to explore the relationship between atmospheric chemistry and climate change; (3) to study the effects of biomass burning in the free troposphere; (4) to measure aerosol number density, size distribution and composition in order to reduce the uncertainties in their effects on the global energy balance. ACE will make a comprehensive set of simultaneous measurements of trace gases, thin clouds, aerosols, and temperature by solar occultation from a satellite in low earth orbit. A high inclination (74 degrees) low earth orbit (650 km) gives ACE coverage of tropical, mid-latitudes and polar regions. The solar occultation advantages are high sensitivity and self-calibration. A high-resolution (0.02 cm-1) infrared Fourier Transform Spectrometer (FTS) operating from 2 to 13 microns (750-4100 cm-1) will measure the vertical distribution of trace gases, and the meteorological variables of temperature and pressure. The ACE concept is derived from the now-retired ATMOS FTS instrument, which flew on the Space Shuttle in 1985, 1992, 1993, 1994. Climate-chemistry coupling may lead to the formation of an Arctic ozone hole. ACE will provide high quality data to confront these model predictions and will monitor polar chemistry as chlorine levels decline. The ACE-FTS can measure water vapor and HDO in the tropical tropopause region to study dehydration and strat-trop exchange. The molecular signatures of massive forest fires will evident in the ACE infrared spectra. The CO2 in our spectra can be used to either retrieve atmospheric pressure or (if the instrument pointing knowledge proves to be satisfactory) for an independent retrieval of a CO2 profile for carbon cycle science. Aerosols and clouds will be monitored using the extinction of solar radiation at

  10. An experiment to use medical I-131 as tracer in a city sewer system

    Energy Technology Data Exchange (ETDEWEB)

    Ulbrich, Susanne; Fischer, Helmut W. [University of Bremen, Institute of Environmental Physics, Otto-Hahn-Allee 1, D-28359 Bremen (Germany)

    2014-07-01

    City sewer systems have to reliably carry residential and industrial wastewater to treatment plants, often mixed with rainwater. Transport in the sewer system is regularly modelled in order to predict sewerage levels, transport velocities and volume discharges. Radioisotopes would be interesting tracers, as they can be detected quickly and without the need of applying wet chemistry. Medical isotopes are released in large quantities (many MBq) by excretion from patients either at the location of administration or from elsewhere, most probably the patient's home. Depending on diagnostic or treatment modality, isotopes of different physical characteristics are used, often bound to compounds of specific metabolic behaviour. Routine environmental surveillance regularly detects the most common diagnostic ({sup 99m}Tc) and therapeutic ({sup 131}I) isotopes in city wastewater samples. Except for {sup 131}I in the case of a nuclear emergency, no contributions from sources other than medical are expected. Medical isotopes therefore might be used for tracing purposes, provided individual inputs can be identified and separated. A field experiment has been designed involving {sup 131}I releases from a single patient who had undergone radioiodine thyroid ablation therapy. This modality is applied after thyroid cancer surgery in order to destroy residual thyroid tissue. Activities up to 5 GBq of {sup 131}I are used which are excreted within few days, as no iodine-retaining thyroid tissue remains. In Germany, about 20,000 of these treatments are performed yearly. For a sewer system of 500,000 inhabitants, about 150 cases would be expected per year, making it quite improbable to have interference between individual patient releases in the same region of the city sewer system. Practically, the radiometric laboratory was informed of the expected release of an (anonymous) patient from the collaborating radiotherapy unit several days in advance, plus the approximate location of

  11. The AQUA-RICH atmospheric neutrino experiment

    CERN Document Server

    Antonioli, P; Bellagamba, L; Chesi, Enrico Guido; Cindolo, F; De Pasquale, S; Ekelöf, T J C; Garbini, M; Giusti, P; Grossheim, A; Pesci, A; Learned, J G; Margotti, A; Pinfold, James L; Sartorelli, G; Séguinot, Jacques; Tarantino, A; Weilhammer, Peter; Ypsilantis, Thomas; Zichichi, A; Zuber, K

    1999-01-01

    We describe a 125 m diameter spherical detector containing 1 Mt of water, capable of high rate observation of atmospheric neutrino events (30000/y). The ring imaging Cherenkov (RICH) technique is used to measure velocity, momentum and direction of particles produced by neutrinos interacting in water. The detector will be sited outdoors (under a 50 m water shield) in a natural (further excavated) pit, probably in Sicily. Spherical reflecting mirrors focus Cherenkov light produced by secondaries from interacting neutrinos. Photons are detected by 5310 hybrid photodiodes (HPDs) of 1 m diameter each with 396 pads of 45*45 mm/sup 2/ on the photocathode surface, demagnified to 9*9 mm/sup 2/ on the silicon sensor. For most tracks the ring width will be dominated by multiple scattering which should allow momentum to be determined. Hadrons of momentum p

  12. Recover Act. Verification of Geothermal Tracer Methods in Highly Constrained Field Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Matthew W. [California State University, Long Beach, CA (United States)

    2014-05-16

    The prediction of the geothermal system efficiency is strong linked to the character of the flow system that connects injector and producer wells. If water flow develops channels or “short circuiting” between injection and extraction wells thermal sweep is poor and much of the reservoir is left untapped. The purpose of this project was to understand how channelized flow develops in fracture geothermal reservoirs and how it can be measured in the field. We explored two methods of assessing channelization: hydraulic connectivity tests and tracer tests. These methods were tested at a field site using two verification methods: ground penetrating radar (GPR) images of saline tracer and heat transfer measurements using distributed temperature sensing (DTS). The field site for these studies was the Altona Flat Fractured Rock Research Site located in northeastern New York State. Altona Flat Rock is an experimental site considered a geologic analog for some geothermal reservoirs given its low matrix porosity. Because soil overburden is thin, it provided unique access to saturated bedrock fractures and the ability image using GPR which does not effectively penetrate most soils. Five boreholes were drilled in a “five spot” pattern covering 100 m2 and hydraulically isolated in a single bedding plane fracture. This simple system allowed a complete characterization of the fracture. Nine small diameter boreholes were drilled from the surface to just above the fracture to allow the measurement of heat transfer between the fracture and the rock matrix. The focus of the hydraulic investigation was periodic hydraulic testing. In such tests, rather than pumping or injection in a well at a constant rate, flow is varied to produce an oscillating pressure signal. This pressure signal is sensed in other wells and the attenuation and phase lag between the source and receptor is an indication of hydraulic connection. We found that these tests were much more effective than constant

  13. Simulation of containment atmosphere stratification experiment using local instantaneous description

    International Nuclear Information System (INIS)

    Babic, M.; Kljenak, I.

    2004-01-01

    An experiment on mixing and stratification in the atmosphere of a nuclear power plant containment at accident conditions was simulated with the CFD code CFX4.4. The original experiment was performed in the TOSQAN experimental facility. Simulated nonhomogeneous temperature, species concentration and velocity fields are compared to experimental results. (author)

  14. Determining concentration fields of tracer plumes for layered porous media in flow-tank experiments

    Science.gov (United States)

    Yu, Zhongbo; Schwartz, Franklin W.

    In the laboratory, computer-assisted image analysis provides an accurate and efficient way to monitor tracer experiments. This paper describes the determination of detailed temporal concentration distributions of tracers in a flow-tank experiment by analyzing photographs of plumes of Rhodamine dye through the glass wall of the tank. The methodology developed for this purpose consists of four steps: (1) digitally scanning black and white negatives obtained from photographs of the flow-tank experiment; (2) calibrating and normalizing each digitized image to a standard optical-density scale by determining the relation between the optical density and pixel value for each image; (3) constructing standard curves relating the concentration in an optical density from five experimental runs with predetermined concentrations (2-97mg/L) and (4) converting the optical density to concentration. The spatial distribution of concentration for two photographs was determined by applying these calibration and conversion procedures to all pixels of the digitized images. This approach provides an efficient way to study patterns of plume evolution and transport mechanisms. Résumé Au laboratoire, l'analyse d'images assistée par ordinateur est un moyen précis et efficace pour suivre certaines expériences de traçage. Ce papier présente comment sont déterminées dans le détail les distributions temporelles de la concentration en traceur au cours d'une expérience d'écoulement en réservoir au moyen de l'analyse de photographies de panaches de rhodamine à travers la paroi de verre du réservoir. La méthodologie développée dans cette expérience suit quatre étapes: (1) digitalisation par balayage des négatifs noir et blanc des prises de vue de l'expérience d'écoulement en réservoir (2) calibration et normalisation de chaque image digitalisée par rapport à une échelle étalon de densité optique en déterminant la relation entre la densité optique et la valeur des pixels

  15. A Tracer Experiment to Understand Dispersion Characteristics at a Nuclear Power Plant Site-Focusing on the Comparison with Predictive Results using Reg. Guide 1.145 model

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hyojoon; Kim, Eunhan; Jeong, Haesun; Hwang, Wontae; Han, Moonhee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    There remains disagreement regarding the application of a Gaussian plume model in PAVAN, as it relates to the complicated geographical features of a coastal area. Therefore, this study was performed in order to figure out the characteristics of the PAVAN program that was developed based on the equations of Gaussian Plume Model, which reflected the actual measured concentration of radioactive materials released to the air. It also evaluated the appropriateness of using a Gaussian plume model for assessing the environmental impact of radiation from a nuclear power plant. In order to analyze the dispersion characteristics of radioactive materials released into the air from the Wolsong nuclear power plant, SF{sub 6} gas was released from the site at night for one hour under stable atmospheric conditions disadvantageous to dilute a tracer gas in this study. The measured concentrations were compared with theoretical estimates derived from meteorological data observed during the experiment period to evaluate the prediction capabilities of the Gaussian plume model. This study conducted a tracer dispersion experiment at the site of Wolsong Nuclear Power Plant site in Korea to analyze the atmospheric dispersion characteristics of radioactive materials. It compared the experimental value with the calculated value using the Gaussian Plume Model as suggested in Reg. 1.145, based on the meteorological data observed in the experiment time period, and evaluated the conservative estimate of the calculated value. In the area where the calculated value is relatively high, the calculated value tends to show higher than the experimental value, which confirmed the conservative manner of the estimating of the calculated value using the Gaussian Plume Model. The short-term exposure of radiation to a human body caused by a nuclear accident would be higher in the area where the atmospheric concentration of radiation is high. Therefore, it is a sufficiently conservative manner to use the

  16. A Tracer Experiment to Understand Dispersion Characteristics at a Nuclear Power Plant Site-Focusing on the Comparison with Predictive Results using Reg. Guide 1.145 model

    International Nuclear Information System (INIS)

    Jeong, Hyojoon; Kim, Eunhan; Jeong, Haesun; Hwang, Wontae; Han, Moonhee

    2014-01-01

    There remains disagreement regarding the application of a Gaussian plume model in PAVAN, as it relates to the complicated geographical features of a coastal area. Therefore, this study was performed in order to figure out the characteristics of the PAVAN program that was developed based on the equations of Gaussian Plume Model, which reflected the actual measured concentration of radioactive materials released to the air. It also evaluated the appropriateness of using a Gaussian plume model for assessing the environmental impact of radiation from a nuclear power plant. In order to analyze the dispersion characteristics of radioactive materials released into the air from the Wolsong nuclear power plant, SF 6 gas was released from the site at night for one hour under stable atmospheric conditions disadvantageous to dilute a tracer gas in this study. The measured concentrations were compared with theoretical estimates derived from meteorological data observed during the experiment period to evaluate the prediction capabilities of the Gaussian plume model. This study conducted a tracer dispersion experiment at the site of Wolsong Nuclear Power Plant site in Korea to analyze the atmospheric dispersion characteristics of radioactive materials. It compared the experimental value with the calculated value using the Gaussian Plume Model as suggested in Reg. 1.145, based on the meteorological data observed in the experiment time period, and evaluated the conservative estimate of the calculated value. In the area where the calculated value is relatively high, the calculated value tends to show higher than the experimental value, which confirmed the conservative manner of the estimating of the calculated value using the Gaussian Plume Model. The short-term exposure of radiation to a human body caused by a nuclear accident would be higher in the area where the atmospheric concentration of radiation is high. Therefore, it is a sufficiently conservative manner to use the Gaussian

  17. Methane emission estimates using chamber and tracer release experiments for a municipal waste water treatment plant

    Science.gov (United States)

    Yver Kwok, C. E.; Müller, D.; Caldow, C.; Lebègue, B.; Mønster, J. G.; Rella, C. W.; Scheutz, C.; Schmidt, M.; Ramonet, M.; Warneke, T.; Broquet, G.; Ciais, P.

    2015-07-01

    This study presents two methods for estimating methane emissions from a waste water treatment plant (WWTP) along with results from a measurement campaign at a WWTP in Valence, France. These methods, chamber measurements and tracer release, rely on Fourier transform infrared spectroscopy and cavity ring-down spectroscopy instruments. We show that the tracer release method is suitable for quantifying facility- and some process-scale emissions, while the chamber measurements provide insight into individual process emissions. Uncertainties for the two methods are described and discussed. Applying the methods to CH4 emissions of the WWTP, we confirm that the open basins are not a major source of CH4 on the WWTP (about 10 % of the total emissions), but that the pretreatment and sludge treatment are the main emitters. Overall, the waste water treatment plant is representative of an average French WWTP.

  18. Experiences of simulated tracer dispersal studies using effluent discharges at Tarapur aquatic environment

    International Nuclear Information System (INIS)

    Sudheendran, V.; Baburajan, A.; Sawane, Pratibha; Rao, D.D.; Hegde, A.G.

    2007-01-01

    The nuclear complex in Tarapur, Maharashtra is a multi facility nuclear site comprising of power reactors and research facilities. Each facility has independent liquid effluent discharge line to Arabian Sea. Experimental studies were conducted to evaluate dilution factors in the aquatic environment using liquid effluent releases as tracer from one of the facilities. 3 H and 137 Cs radioisotopes present in the routine releases were used as simulated tracer nuclides. The dilution factors(D.F) observed for tritium were in the range of 20-20000 in a distance range of 10 m to 1500 m respectively and for 137 Cs the D.F. were in the range of 50 to 900 over a distance range of 10-200 m. The paper describes the analytical methodology and sampling scenarios and the results of dilution factors obtained for Tarapur aquatic environment. (author)

  19. Estimation of Knudsen diffusion coefficients from tracer experiments conducted with a binary gas system and a porous medium

    Science.gov (United States)

    Hibi, Yoshihiko; Kashihara, Ayumi

    2018-03-01

    A previous study has reported that Knudsen diffusion coefficients obtained by tracer experiments conducted with a binary gas system and a porous medium are consistently smaller than those obtained by permeability experiments conducted with a single-gas system and a porous medium. To date, however, that study is the only one in which tracer experiments have been conducted with a binary gas system. Therefore, to confirm this difference in Knudsen diffusion coefficients, we used a method we had developed previously to conduct tracer experiments with a binary carbon dioxide-nitrogen gas system and five porous media with permeability coefficients ranging from 10-13 to 10-11 m2. The results showed that the Knudsen diffusion coefficient of N2 (DN2) (cm2/s) was related to the effective permeability coefficient ke (m2) as DN2 = 7.39 × 107ke0.767. Thus, the Knudsen diffusion coefficients of N2 obtained by our tracer experiments were consistently 1/27 of those obtained by permeability experiments conducted with many porous media and air by other researchers. By using an inversion simulation to fit the advection-diffusion equation to the distribution of concentrations at observation points calculated by mathematically solving the equation, we confirmed that the method used to obtain the Knudsen diffusion coefficient in this study yielded accurate values. Moreover, because the Knudsen diffusion coefficient did not differ when columns with two different lengths, 900 and 1500 mm, were used, this column property did not influence the flow of gas in the column. The equation of the dusty gas model already includes obstruction factors for Knudsen diffusion and molecular diffusion, which relate to medium heterogeneity and tortuosity and depend only on the structure of the porous medium. Furthermore, there is no need to take account of any additional correction factor for molecular diffusion except the obstruction factor because molecular diffusion is only treated in a multicomponent

  20. Recommendations for the determination of migration parameters by field experiments (tracer tests)

    International Nuclear Information System (INIS)

    Adam, C.

    1989-01-01

    The hydrogeologic review and assessment of candidate sites for nuclear power plants includes expertises on the potential subsurface migration of radionuclides in the event of accident conditions. To this end, knowledge of representative migration parameters is required. Detailed recommendations are given for determining such parameters by tracer field tests, for using standardized terminology in their practical conduct as well as for interpreting the data obtained. Also, mention has been made of recent work reported by other authors on this topic. 31 refs. (author)

  1. Hydraulic and tracer experiments in the TVO research tunnel 1993- 1994

    International Nuclear Information System (INIS)

    Hautojaervi, A.; Ilvonen, M.; Vieno, T.; Viitanen, P.

    1995-04-01

    Three full-size deposition holes (diameter 1.5 m, depth 7.5 m) for spent fuel canisters in a KBS-3 type repository have been bored with a new fullface boring method in the TVO Research Tunnel. The Research Tunnel lies in the crystalline bedrock at the depth of 60 metres in the VLJ Repository for low and medium level waste. The holes are 6 metres apart. The boring tests were accompanied by comprehensive pre- and post-characterization of the rock and the bored wells. The inflow rates of groundwater in two of the three full-size holes are 6 and 20 litres/hour. The well in the middle is almost dry as expected on the basis of the pre-characterization. In the tracer tests two different tracers, a dye and a radioactive tracer, were used at the same time. The comprehensive data analysis performed showed that novel techniques (e.g. Extreme Value Estimation, EVE) can be successfully applied to determine the impulse response from the experimental results even in cases where the measured signals are disturbed. Hydraulic and tracer tests as well as visual inspection of the inflow gave clear indications of flow and transport in sparse and narrow channels. Transport velocities could be predicted with a reasonable accuracy by using a simple concept of fracture cavities determining the transport time and 'bottlenecks' causing the hydraulic resistance. The observed non-Fickian dispersion is thought to be caused by velocity differences over the channel width or by diffusion into stagnant pools in the fracture filling. (orig.) (36 refs., 67 figs., 1 tab.)

  2. Chemical Tracer Methods: Chapter 7

    Science.gov (United States)

    Healy, Richard W.

    2017-01-01

    Tracers have a wide variety of uses in hydrologic studies: providing quantitative or qualitative estimates of recharge, identifying sources of recharge, providing information on velocities and travel times of water movement, assessing the importance of preferential flow paths, providing information on hydrodynamic dispersion, and providing data for calibration of water flow and solute-transport models (Walker, 1998; Cook and Herczeg, 2000; Scanlon et al., 2002b). Tracers generally are ions, isotopes, or gases that move with water and that can be detected in the atmosphere, in surface waters, and in the subsurface. Heat also is transported by water; therefore, temperatures can be used to trace water movement. This chapter focuses on the use of chemical and isotopic tracers in the subsurface to estimate recharge. Tracer use in surface-water studies to determine groundwater discharge to streams is addressed in Chapter 4; the use of temperature as a tracer is described in Chapter 8.Following the nomenclature of Scanlon et al. (2002b), tracers are grouped into three categories: natural environmental tracers, historical tracers, and applied tracers. Natural environmental tracers are those that are transported to or created within the atmosphere under natural processes; these tracers are carried to the Earth’s surface as wet or dry atmospheric deposition. The most commonly used natural environmental tracer is chloride (Cl) (Allison and Hughes, 1978). Ocean water, through the process of evaporation, is the primary source of atmospheric Cl. Other tracers in this category include chlorine-36 (36Cl) and tritium (3H); these two isotopes are produced naturally in the Earth’s atmosphere; however, there are additional anthropogenic sources of them.

  3. A Shuttle Upper Atmosphere Mass Spectrometer /SUMS/ experiment

    Science.gov (United States)

    Blanchard, R. C.; Duckett, R. J.; Hinson, E. W.

    1982-01-01

    A magnetic mass spectrometer is currently being adapted to the Space Shuttle Orbiter to provide repeated high altitude atmosphere data to support in situ rarefied flow aerodynamics research, i.e., in the high velocity, low density flight regime. The experiment, called Shuttle Upper Atmosphere Mass Spectrometer (SUMS), is the first attempt to design mass spectrometer equipment for flight vehicle aerodynamic data extraction. The SUMS experiment will provide total freestream atmospheric quantitites, principally total mass density, above altitudes at which conventional pressure measurements are valid. Experiment concepts, the expected flight profile, tradeoffs in the design of the total system and flight data reduction plans are discussed. Development plans are based upon a SUMS first flight after the Orbiter initial development flights.

  4. Enhancing the activation of silicon carbide tracer particles for PEPT applications using gas-phase deposition of alumina at room temperature and atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Valdesueiro, D. [Delft University of Technology, Department of Chemical Engineering, 2628 BL Delft (Netherlands); Garcia-Triñanes, P., E-mail: p.garcia@surrey.ac.uk [Department of Chemical and Process Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Meesters, G.M.H.; Kreutzer, M.T. [Delft University of Technology, Department of Chemical Engineering, 2628 BL Delft (Netherlands); Gargiuli, J.; Leadbeater, T.W.; Parker, D.J. [Positron Imaging Centre, School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Seville, J.P.K. [Department of Chemical and Process Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Ommen, J.R. van, E-mail: j.r.vanommen@tudelft.nl [Delft University of Technology, Department of Chemical Engineering, 2628 BL Delft (Netherlands)

    2016-01-21

    We have enhanced the radio-activation efficiency of SiC (silicon carbide) particles, which by nature have a poor affinity towards {sup 18}F ions, to be employed as tracers in studies using PEPT (Positron Emission Particle Tracking). The resulting SiC–Al{sub 2}O{sub 3} core–shell structure shows a good labelling efficiency, comparable to γ-Al{sub 2}O{sub 3} tracer particles, which are commonly used in PEPT. The coating of the SiC particles was carried at 27±3 °C and 1 bar in a fluidized bed reactor, using trimethylaluminium and water as precursors, by a gas phase technique similar to atomic layer deposition. The thickness of the alumina films, which ranged from 5 to 500 nm, was measured by elemental analysis and confirmed with FIB-TEM (focused ion beam – transmission electron microscope), obtaining consistent results from both techniques. By depositing such a thin film of alumina, properties that influence the hydrodynamic behaviour of the SiC particles, such as size, shape and density, are hardly altered, ensuring that the tracer particle shows the same flow behaviour as the other particles. The paper describes a general method to improve the activation efficiency of materials, which can be applied for the production of tracer particles for many other applications too. - Highlights: • We deposited Al{sub 2}O{sub 3} films on SiC particles at ambient conditions in a fluidized bed. • The affinity of {sup 18}F ions towards Al{sub 2}O{sub 3}–SiC particle was improved compared to SiC. • We used the Al{sub 2}O{sub 3}–SiC activated particle as tracer in a PEPT experiment. • Tracer particles have suitable activity for accurate tracking. • The Al{sub 2}O{sub 3} film is thin enough not to alter the particle size, shape and density.

  5. Measurement of Kr-85 and Xe-133 as undisturbed tracers for the representing of atmospheric transport after disposal of radioactivity from nuclear facilities

    International Nuclear Information System (INIS)

    Frank, G.; Steinkopff, T.; Salvamoser, J.

    2016-01-01

    The Deutscher Wetterdienst (DWD, German Meteorological Service) operates since 1996 a sampling and measurement device for the radioactive rare gases Kr-85 and Xe-133 in Offenbach. These measurements are embedded in the German Measurement and Information System for Monitoring Environmental Radioactivity (Integriertes Mess- und Informationssystem zur Ueberwachung der Radioaktivitaet in der Umwelt, IMIS) [1]. In addition to these measurements the DWD is sampling rare gases in Potsdam and since 2014 in Trier in cooperation with the Bundesamt fuer Strahlenschutz (Federal Office for Radiation Protection, BfS). In the frame of the Global Atmosphere Watch (GAW)-program of the WMO the DWD operated a sampling station at the Zugspitze (Schneefernerhaus) from 1999 to 2005. This location at the Zugspitze is well suited for the observation of long distance transport of Kr-85 in the higher atmosphere. The DWD in Offenbach operates a complex analytical system for the measurement of Kr-85 and Xe-133 since 1998. This system consists of sampling with first enrichment, second enrichment, gas chromatographic separation and preparation of Krypton and Xenon and measurement of Kr-85 and Xe-133. Using the example Fukushima, it is shown, that the radioactive rare gases Kr-85 and Xe-133 are well undisturbed tracers for atmospheric transport in case of a nuclear accident or routine nuclear reprocessing plants. Measurements of Xe-133, I-131, Cs-137 and Kr-85 are correlated with source and atmospheric transport to the sampling sites at Offenbach and Potsdam.

  6. New insights to the use of ethanol in automotive fuels: a stable isotopic tracer for fossil- and bio-fuel combustion inputs to the atmosphere.

    Science.gov (United States)

    Giebel, Brian M; Swart, Peter K; Riemer, Daniel D

    2011-08-01

    Ethanol is currently receiving increased attention because of its use as a biofuel or fuel additive and because of its influence on air quality. We used stable isotopic ratio measurements of (13)C/(12)C in ethanol emitted from vehicles and a small group of tropical plants to establish ethanol's δ(13)C end-member signatures. Ethanol emitted in exhaust is distinctly different from that emitted by tropical plants and can serve as a unique stable isotopic tracer for transportation-related inputs to the atmosphere. Ethanol's unique isotopic signature in fuel is related to corn, a C4 plant and the primary source of ethanol in the U.S. We estimated a kinetic isotope effect (KIE) for ethanol's oxidative loss in the atmosphere and used previous assumptions with respect to the fractionation that may occur during wet and dry deposition. A small number of interpretive model calculations were used for source apportionment of ethanol and to understand the associated effects resulting from atmospheric removal. The models incorporated our end-member signatures and ambient measurements of ethanol, known or estimated source strengths and removal magnitudes, and estimated KIEs associated with atmospheric removal processes for ethanol. We compared transportation-related ethanol signatures to those from biogenic sources and used a set of ambient measurements to apportion each source contribution in Miami, Florida-a moderately polluted, but well ventilated urban location.

  7. Lower Atmospheric Boundary Layer Experiment (LABLE) Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Klein, P [University of Oklahoma - School of Meteorology; Bonin, TA; Newman, JF [National Renewable Energy Laboratory; Turner, DD [National Oceanic and Atmospheric Administration; Chilson, P [University of Oklahoma; Blumberg, WG [University of Oklahoma; Mishra, S; Wainwright, CE; Carney, M [University of Oklahoma - School of Meteorology; Jacobsen, EP [University of Oklahoma; Wharton, S [Lawrence Livermore National Laboratory

    2015-11-01

    The Lower Atmospheric Boundary Layer Experiment (LABLE) included two measurement campaigns conducted at the Atmospheric Radiation Measurement (ARM) Southern Great Plains site in Oklahoma during 2012 and 2013. LABLE was designed as a multi-phase, low-cost collaboration among the University of Oklahoma, the National Severe Storms Laboratory, Lawrence Livermore National Laboratory, and the ARM program. A unique aspect was the role of graduate students in LABLE. They served as principal investigators and took the lead in designing and conducting experiments using different sampling strategies to best resolve boundary-layer phenomena.

  8. Verification of atmospheric diffusion models using data of long term atmospheric diffusion experiments

    International Nuclear Information System (INIS)

    Tamura, Junji; Kido, Hiroko; Hato, Shinji; Homma, Toshimitsu

    2009-03-01

    Straight-line or segmented plume models as atmospheric diffusion models are commonly used in probabilistic accident consequence assessment (PCA) codes due to cost and time savings. The PCA code, OSCAAR developed by Japan Atomic Energy Research Institute (Present; Japan Atomic Energy Agency) uses the variable puff trajectory model to calculate atmospheric transport and dispersion of released radionuclides. In order to investigate uncertainties involved with the structure of the atmospheric dispersion/deposition model in OSCAAR, we have introduced the more sophisticated computer codes that included regional meteorological models RAMS and atmospheric transport model HYPACT, which were developed by Colorado State University, and comparative analyses between OSCAAR and RAMS/HYPACT have been performed. In this study, model verification of OSCAAR and RAMS/HYPACT was conducted using data of long term atmospheric diffusion experiments, which were carried out in Tokai-mura, Ibaraki-ken. The predictions by models and the results of the atmospheric diffusion experiments indicated relatively good agreements. And it was shown that model performance of OSCAAR was the same degree as it of RAMS/HYPACT. (author)

  9. Study on the metabolic characteristics of renal imaging agent {sup 99m}Tc-PAHIDA with tracer experiment

    Energy Technology Data Exchange (ETDEWEB)

    Shoupeng, Zhu; Liuyi, Wang; Mingyue, Lun [Suzhou Medical Coll., JS (China); and others

    1995-05-01

    Tracer experiment showed that {sup 99m}Tc-PAHIDA was distributed predominantly in kidney. The distribution in other tissue was in the following descending order: heart, gastrointestinal tract, liver, spleen, muscle, adipose tissue, testes, and brain. The smaller the intravenous dose, the lower the proportion of the drug was combined to plasma protein and the more the drug was distributed in kidney. Excretion of {sup 99m}Tc-PAHIDa via urine was rapid and was in its original form as shown by radiochromatography.

  10. Atmospheric chemistry and physics in the atmosphere of a developed megacity (London: an overview of the REPARTEE experiment and its conclusions

    Directory of Open Access Journals (Sweden)

    R. M. Harrison

    2012-03-01

    Full Text Available The REgents PARk and Tower Environmental Experiment (REPARTEE comprised two campaigns in London in October 2006 and October/November 2007. The experiment design involved measurements at a heavily trafficked roadside site, two urban background sites and an elevated site at 160–190 m above ground on the BT Tower, supplemented in the second campaign by Doppler lidar measurements of atmospheric vertical structure. A wide range of measurements of airborne particle physical metrics and chemical composition were made as well as measurements of a considerable range of gas phase species and the fluxes of both particulate and gas phase substances. Significant findings include (a demonstration of the evaporation of traffic-generated nanoparticles during both horizontal and vertical atmospheric transport; (b generation of a large base of information on the fluxes of nanoparticles, accumulation mode particles and specific chemical components of the aerosol and a range of gas phase species, as well as the elucidation of key processes and comparison with emissions inventories; (c quantification of vertical gradients in selected aerosol and trace gas species which has demonstrated the important role of regional transport in influencing concentrations of sulphate, nitrate and secondary organic compounds within the atmosphere of London; (d generation of new data on the atmospheric structure and turbulence above London, including the estimation of mixed layer depths; (e provision of new data on trace gas dispersion in the urban atmosphere through the release of purposeful tracers; (f the determination of spatial differences in aerosol particle size distributions and their interpretation in terms of sources and physico-chemical transformations; (g studies of the nocturnal oxidation of nitrogen oxides and of the diurnal behaviour of nitrate aerosol in the urban atmosphere, and (h new information on the chemical composition and source apportionment of particulate

  11. 26Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi.

    1990-01-01

    Accelerator mass spectrometry (AMS) was applied for 26 Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26 Al as a tracer. When 26 Al was intraperitoneally injected into rats, a considerable amount of 26 Al was incorporated into the cerebrum after 5-35 days of the injection. (author)

  12. Diffusion near buildings as determined from atmospheric tracer experiments. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Sagendorf, J.F.; Ricks, N.R.; Start, G.E.; Dickson, C.R.

    1980-09-01

    Data from the innermost arcs and roof top samplers of the Rancho Seco and EOCR field studies were used to examine diffusion close to a building. The minimum length plume paths were determined from each release location to each sampler position at these two test sites. Measured concentrations, normalized by source strength (C/Q), were plotted versus plume path length and an envelope containing 95% of the measured values of C/Q was determined. The curves from the two sites were similar in shape and implied three zones of diffusion. Comparisons were also made with current NRC methods for predicting maximum expected concentrations close to a building. The NRC model overestimated concentrations in all but one case. The model was generally within an order of magnitude at EOCR, and within two orders of magnitude at Rancho Seco.

  13. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    International Nuclear Information System (INIS)

    Gonzalez Sanchez, F.

    2007-11-01

    /cm 3 , in order to reduce the pore sizes and to better study the dynamic properties of water close to the water-clay interface. We compared the water dynamics in fully hydrated compacted clays, at two significantly different time-space scales, in an attempt to distinguish the relevant features of the water transport. A fundamental microscopic investigation, tracing down to the atomic level was carried out, by neutron scattering, using time-of-flight and backscattering techniques. A classical macroscopic study was performed by using tracer through-diffusion methods. At the macroscopic level (time/spatial scale of about hours/mm to cm) the water diffusion depends strongly on the clay pore size and arrangement of the particles. However, at the microscopic level (time/spatial scale of about ten to hundred picosecond/10 -8 cm) the diffusion is governed by the local environment, which concerns to cations and clay surfaces and less to the particle arrangement. For a further understanding of this local environment, the water diffusion in clays was also measured at different hydration states, to vary the fraction of interlayer or external layer water, as compared to free pore water. The large difference in the diffusion paths of the two selected techniques makes a direct comparison of water diffusivities impossible. Therefore, two possibilities were established: An indirect comparison by connecting the results for diffusion coefficient at the two different scales through pure geometrical and electrostatic factors; and a direct comparison through the activation energy E a which was estimated from the dependence of the diffusion coefficients on the temperature. In contrast to the macroscopic diffusion coefficients, the activation energy is probably less influenced by geometrical factors and more by microscopic interactions, and thus could possibly be directly compared at the two different scales. The research was accomplished by a detailed characterization of the clay samples

  14. Water diffusion through compacted clays analyzed by neutron scattering and tracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Sanchez, F

    2007-11-15

    /cm{sup 3}, in order to reduce the pore sizes and to better study the dynamic properties of water close to the water-clay interface. We compared the water dynamics in fully hydrated compacted clays, at two significantly different time-space scales, in an attempt to distinguish the relevant features of the water transport. A fundamental microscopic investigation, tracing down to the atomic level was carried out, by neutron scattering, using time-of-flight and backscattering techniques. A classical macroscopic study was performed by using tracer through-diffusion methods. At the macroscopic level (time/spatial scale of about hours/mm to cm) the water diffusion depends strongly on the clay pore size and arrangement of the particles. However, at the microscopic level (time/spatial scale of about ten to hundred picosecond/10{sup -8} cm) the diffusion is governed by the local environment, which concerns to cations and clay surfaces and less to the particle arrangement. For a further understanding of this local environment, the water diffusion in clays was also measured at different hydration states, to vary the fraction of interlayer or external layer water, as compared to free pore water. The large difference in the diffusion paths of the two selected techniques makes a direct comparison of water diffusivities impossible. Therefore, two possibilities were established: An indirect comparison by connecting the results for diffusion coefficient at the two different scales through pure geometrical and electrostatic factors; and a direct comparison through the activation energy E{sub a} which was estimated from the dependence of the diffusion coefficients on the temperature. In contrast to the macroscopic diffusion coefficients, the activation energy is probably less influenced by geometrical factors and more by microscopic interactions, and thus could possibly be directly compared at the two different scales. The research was accomplished by a detailed characterization of the clay

  15. Atmospherical experiment in Angra I plant for characterizing the effluent transport threw in the atmospheric

    International Nuclear Information System (INIS)

    Silva Lobo, M.A. da; Kronemberger, B.M.E.

    1989-01-01

    Available as short communication only. The Environmental Safety Division of the Nuclear Safety and Fuel Department from FURNAS Electric Station S.A. joint with the National Oceanic and Atmospheric Administration (NOAA), achieved a field experiment for characterizing the atmospheric transport and diffusion in the site complex of Angra I Nuclear Power Plant. The complex topography with the thick vegetation and the neighbour building bring problems for the modelling of the effluent transport and the dispersion. The actual meteorological measure system is automatic and compound with four towers. An intensive atmospheric measure with captive balloon is included, and the collected data shows that the site flux is strongly influenced by the topography and insolation. (C.G.C.). 2 figs

  16. Study of the atmospheric neutrino oscillations in the Frejus experiment

    International Nuclear Information System (INIS)

    Perdereau, O.

    1989-05-01

    The behavior of atmospheric neutrinos is investigated. It is a zero mass, zero charge and weak interacting particle. The aim of the investigation is to search for non standard phenomena, such as neutrino oscillations. The neutrino theoretical properties are discussed and the physical parameters experimental limits are recalled. The analysis of the approximately 200 events from atmospheric neutrinos observed in Frejus detector is carried out. The results and simulation of neutrino interactions are presented. The data analysis induces to the exclusion of neutrino oscillation hypothesis from some models. Three cases of oscillations involving two neutrino flavors are analyzed. The effect of a third flavor is also taken into account. The present data and those from IMB and Kamiokande experiments are compared. Topics involving investigations on the superposition of a signal and the atmospheric neutrinos are included [fr

  17. Molecular line parameters for the atmospheric trace molecule spectroscopy experiment

    Science.gov (United States)

    Brown, L. R.; Farmer, C. B.; Toth, R. A.; Rinsland, Curtis P.

    1987-01-01

    During its first mission in 1985 onboard Spacelab 3, the ATMOS (atmospheric trace molecule spectroscopy) instrument, a high speed Fourier transform spectrometer, produced a large number of high resolution infrared solar absorption spectra recorded in the occultation mode. The analysis and interpretation of these data in terms of composition, chemistry, and dynamics of the earth's upper atmosphere required good knowledge of the molecular line parameters for those species giving rise to the absorptions in the atmospheric spectra. This paper describes the spectroscopic line parameter database compiled for the ATMOS experiment and referenced in other papers describing ATMOS results. With over 400,000 entries, the linelist catalogs parameters of 46 minor and trace species in the 1-10,000/cm region.

  18. Sensitivity study of land biosphere CO2 exchange through an atmospheric tracer transport model using satellite-derived vegetation index data

    International Nuclear Information System (INIS)

    Knorr, W.; Heimann, M.

    1994-01-01

    We develop a simple, globally uniform model of CO 2 exchange between the atmosphere and the terrestrial biosphere by coupling the model with a three-dimensional atmospheric tracer transport model using observed winds, and checking results against observed concentrations of CO 2 at various monitoring sites. CO 2 fluxes are derived from observed greenness using satellite-derived Global Vegetation Index data, combined with observations of temperature, radiation, and precipitation. We explore a range of CO 2 flux formulations together with some modifications of the modelled atmospheric transport. We find that while some formulations can be excluded, it cannot be decided whether or not to make CO 2 uptake and release dependent on water stress. It appears that the seasonality of net CO 2 fluxes in the tropics, which would be expected to be driven by water availability, is small and is therefore not visible in the seasonal cycle of atmospheric CO 2 . The latter is dominated largely by northern temperate and boreal vegetation, where seasonality is mostly temperature determined. We find some evidence that there is still considerable CO 2 release from soils during northern-hemisphere winter. An exponential air temperature dependence of soil release with a Q 10 of 1.5 is found to be most appropriate, with no cutoff at low freezing temperatures. This result is independent of the year from which observed winds were taken. This is remarkable insofar as year-to-year changes in modelled CO 2 concentrations caused by changes in the wind data clearly outweigh those caused by year-to-year variability in the climate and vegetation index data. (orig.)

  19. Atmospheric dispersion experiments over complex terrain in a spanish valley site (Guardo-90)

    International Nuclear Information System (INIS)

    Ibarra, J.I.

    1991-01-01

    An intensive field experimental campaign was conducted in Spain to quantify atmospheric diffusion within a deep, steep-walled valley in rough, mountainous terrain. The program has been sponsored by the spanish companies of electricity and is intended to validate existing plume models and to provide the scientific basis for future model development. The atmospheric dispersion and transport processes in a 40x40 km domain were studied in order to evaluate SO 2 and SF 6 releases from an existing 185 m chimney and ground level sources in a complex terrain valley site. Emphasis was placed on the local mesoscale flows and light wind stable conditions. Although the measuring program was intensified during daytime for dual tracking of SO 2 /SF 6 from an elevated source, nighttime experiments were conducted for mountain-valley flows characterization. Two principle objectives were pursued: impaction of plumes upon elevated terrain, and diffusion of gases within the valley versus diffusion over flat, open terrain. Artificial smoke flows visualizations provided qualitative information: quantitative diffusion measurements were obtained using sulfur hexafluoride gas with analysis by highly sensitive electron capture gas chromatographs systems. Fourteen 2 hours gaseous tracer releases were conducted

  20. Tracer theory

    International Nuclear Information System (INIS)

    Margrita, R.

    1988-09-01

    Tracers are used in many fields of science to investigate mass transfer. The scope of tracers applications in Service of Applications Radioisotopes (S.A.R.-France) is large and concerns natural and industrial systems such as Sciences of earth: hydrology - civil engineering - Sedimentology - environmental studies. Industrial field: chemical engineering - mechanical engineering. A general tracer methodology has been developed in our laboratories from these different applications fields and this paper shows these different points of view in using tracers; our wish is that the methods used in an experimental field can be employed in an another one

  1. First atmospheric diffusion experiment compaign at the Angra site. Analysis of the data measured

    International Nuclear Information System (INIS)

    Nicolli, D.

    1986-07-01

    An analysis of the data measured during the first atmospheric diffusion experiment campaign at the Angra site is presented. Some time before the diffusion experiments, with tritiated water vapor used as a tracer (HTO) could be started, many preparatory studies had to be concluded due to the local complex terrain surrounded by steep hills on three sides and a bay in the southern direction. An introductory account of these previous steps is given. Tritiated water vapor was released from a 100m-high tower and air humidity sampled at 25 locations as far as 1Km downwind of the source. An elaborated isoconcentration analysis indicates the plume spread has a Gaussian distribution in the horizontal plane up to the edge of the site's area bordered by the hill's top (about 1Km far-off). Nevertheless the Gaussian model has a restricted applicability at some parts of the site because of the terrain unevenness. In general, the results are comparable to those obtained in other countries for complex terrain. Meanwhile, the Angra's experiments seem only to validate the Gaussian model for short range dispersion from an elevated source. For releases in the lowest layer, the Gaussian model might not be valid. The isoconcentration analysis strengthens the assumption of sea breeze recirculation on the site. (Author) [pt

  2. Tracer-tracer relations as a tool for research on polar ozone loss

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Rolf

    2010-07-01

    The report includes the following chapters: (1) Introduction: ozone in the atmosphere, anthropogenic influence on the ozone layer, polar stratospheric ozone loss; (2) Tracer-tracer relations in the stratosphere: tracer-tracer relations as a tool in atmospheric research; impact of cosmic-ray-induced heterogeneous chemistry on polar ozone; (3) quantifying polar ozone loss from ozone-tracer relations: principles of tracer-tracer correlation techniques; reference ozone-tracer relations in the early polar vortex; impact of mixing on ozone-tracer relations in the polar vortex; impact of mesospheric intrusions on ozone-tracer relations in the stratospheric polar vortex calculation of chemical ozone loss in the arctic in March 2003 based on ILAS-II measurements; (4) epilogue.

  3. Stable hydrogen isotopic composition of n-alkanes in atmospheric aerosols as a tracer for the source region of terrestrial plant waxes

    Science.gov (United States)

    Yamamoto, S.; Kawamura, K.

    2009-12-01

    growing leaves in Tokyo, which confirms the usefulness of the δD of long chain n-alkanes as a tracer for the source region of terrestrial plant waxes in atmospheric aerosols.

  4. Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning

    Directory of Open Access Journals (Sweden)

    P. Q. Fu

    2012-09-01

    Full Text Available Organic tracer compounds, as well as organic carbon (OC, elemental carbon (EC, water-soluble organic carbon (WSOC, and stable carbon isotope ratios (δ13C of total carbon (TC have been investigated in aerosol samples collected during early and late periods of the Mount Tai eXperiment 2006 (MTX2006 field campaign in the North China Plain. Total solvent-extractable fractions were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs. In early June when the field burning activities of wheat straws in the North China Plain were very active, the total identified organics (2090 ± 1170 ng m−3 were double those in late June (926 ± 574 ng m−3. All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88–1210 ng m−3, mean 403 ng m−3 was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude, which could be further transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary

  5. Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning

    Science.gov (United States)

    Fu, P. Q.; Kawamura, K.; Chen, J.; Li, J.; Sun, Y. L.; Liu, Y.; Tachibana, E.; Aggarwal, S. G.; Okuzawa, K.; Tanimoto, H.; Kanaya, Y.; Wang, Z. F.

    2012-09-01

    Organic tracer compounds, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios (δ13C) of total carbon (TC) have been investigated in aerosol samples collected during early and late periods of the Mount Tai eXperiment 2006 (MTX2006) field campaign in the North China Plain. Total solvent-extractable fractions were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA) tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs). In early June when the field burning activities of wheat straws in the North China Plain were very active, the total identified organics (2090 ± 1170 ng m-3) were double those in late June (926 ± 574 ng m-3). All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88-1210 ng m-3, mean 403 ng m-3) was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude, which could be further transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 24% (up to 64%) of the

  6. Diurnal variations of organic molecular tracers and stable carbon isotopic compositions in atmospheric aerosols over Mt. Tai in North China Plain: an influence of biomass burning

    Science.gov (United States)

    Fu, P. Q.; Kawamura, K.; Chen, J.; Li, J.; Sun, Y. L.; Liu, Y.; Tachibana, E.; Aggarwal, S. G.; Okuzawa, K.; Tanimoto, H.; Kanaya, Y.; Wang, Z. F.

    2012-04-01

    Organic tracer compounds of tropospheric aerosols, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios (δ13C) of total carbon (TC) have been investigated for aerosol samples collected during early and late periods of Mount Tai eXperiment 2006 (MTX2006) field campaign in North China Plain. Total solvent extracts were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA) tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs). In early June when the field burning activities of wheat straws in North China Plain were very active, the total identified organics (2090 ± 1170 ng m-3) were double those in late June (926 ± 574 ng m-3). All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88-1210 ng m-3, 403 ng m-3) was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude and then transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 24% (up to 64%) of the OC in the Mt. Tai

  7. Influence of vehicular emissions on atmospheric CH4 and NMHC mixing ratios and its correlation with CO and other VOCs tracers in Mexico City

    Science.gov (United States)

    Solano-Murillo, M.; Torres-Jardón, R.; Ruiz-Suárez, L. G.; Barrera-Huertas, H.; Hernandez-Solis, J. M.

    2016-12-01

    The Mexico City Metropolitan Area (MCMA) is one of the world's largest and most polluted urban areas. A recent GHC emission inventory for MCMA suggests that vehicular emissions contribute with around 37% of CH4, followed by landfills and dump garbage areas (30%) and construction and manufacturing (27%). Contrary to other urban areas, natural gas is not the main fuel used in MCMA, neither for domestic and industrial heating, nor for transportation. Therefore, there is a great uncertainty about who is the main contributor of CH4 emissions. An intensive monitoring campaign of methane (CH4), Non-methane hydrocarbons (NMHC) and carbon monoxide (CO) was performed between February and March 2015 in southwest MCMA. Methane concentrations showed sometimes a diurnal pattern similar to those of CO and to NMHC but most of the time this similarity was lost (CH4 vs CO, R2 = 0.27; CH4 vs NMHC, R2 = 0.28). However, NMHC correlated well with CO (R2 = 0.75). The intercepts of the CH4-CO correlation resulted in [CH4] 1.8 ppm and that of the CO-NMHC correlation in [CO] 0.080 ppb. The lack of agreement between CH4 and CO indicates these species do not come from the same sources. The results suggest that vehicular emissions are not significant contributors to atmospheric CH4 and that the background methane concentration has not change significantly in 25 years. An attempt to correlate some tracers COVs tracers of vehicular and biomass burning with CH4, NMHC and CH4 is done.

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

    International Nuclear Information System (INIS)

    Foster, P.M.

    1988-11-01

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

  9. Atmospheric statistical dynamic models. Climate experiments: albedo experiments with a zonal atmospheric model

    International Nuclear Information System (INIS)

    Potter, G.L.; Ellsaesser, H.W.; MacCracken, M.C.; Luther, F.M.

    1978-06-01

    The zonal model experiments with modified surface boundary conditions suggest an initial chain of feedback processes that is largest at the site of the perturbation: deforestation and/or desertification → increased surface albedo → reduced surface absorption of solar radiation → surface cooling and reduced evaporation → reduced convective activity → reduced precipitation and latent heat release → cooling of upper troposphere and increased tropospheric lapse rates → general global cooling and reduced precipitation. As indicated above, although the two experiments give similar overall global results, the location of the perturbation plays an important role in determining the response of the global circulation. These two-dimensional model results are also consistent with three-dimensional model experiments. These results have tempted us to consider the possibility that self-induced growth of the subtropical deserts could serve as a possible mechanism to cause the initial global cooling that then initiates a glacial advance thus activating the positive feedback loop involving ice-albedo feedback (also self-perpetuating). Reversal of the cycle sets in when the advancing ice cover forces the wave-cyclone tracks far enough equatorward to quench (revegetate) the subtropical deserts

  10. Experiments for separation and purification of Mo-99 from uranium solution with fission products as tracers

    International Nuclear Information System (INIS)

    Androne, Gabriela Elena; Matei, Ana

    2007-01-01

    Technetium-99 m ( 99m Tc, T 1/2 = 6 hours), one of the most utilised radioisotopes in nuclear medicine, is generated through the beta decay of 99 Mo (T 1/2 = 66 hours) and which will decay through isomer transition to 99 Tc ( T 1/2 = 2.10 5 years) through the emission of a gamma radiation with the energy of 0.140 MeV. The work presents the phases of the process of Mo separation and purification at a tracer level. The tests performed in the laboratory have established the optimum conditions for the separation and purification of Molybdenum. To establish the separation and purification parameters, a synthetic solution which contains the elements which result following the irradiation of a low enriched Uranium foil weighing 10 g (∼20 % 235 U). To mark this solution, about 13 mg of UO 2 10% 235 U was irradiated for 2000 s, at a flux of about 7x10 12 n/cm 2 s. This amount of UO 2 will be added to the above-mentioned solution after dissolution. The method for separating the Molybdenum from irradiated Uranium solution is one of selective precipitation of Mo with α-benzoin-oxyme (α- BO). To purify the Molybdenum solution, two purification columns were utilised. Their role was to absorb the impurities remained in the mass of the precipitate. They and the Molybdenum have passed into the solution simultaneously, allowing the Molybdenum to pass. These columns are: the column with active charcoal (AC)+ active charcoal covered with silver (AgAC); active charcoal column (AC)+active charcoal covered with silver (AgAC)+hydrated zirconium oxide (HZO). Although all the phases of the process are performed with high yields, the final yields of recovery of Mo from U solutions are higher than 80%. (authors)

  11. Study of the daily and seasonal atmospheric CH4 mixing ratio variability in a rural Spanish region using 222Rn tracer

    Science.gov (United States)

    Grossi, Claudia; Vogel, Felix R.; Curcoll, Roger; Àgueda, Alba; Vargas, Arturo; Rodó, Xavier; Morguí, Josep-Anton

    2018-04-01

    The ClimaDat station at Gredos (GIC3) has been continuously measuring atmospheric (dry air) mixing ratios of carbon dioxide (CO2) and methane (CH4), as well as meteorological parameters, since November 2012. In this study we investigate the atmospheric variability of CH4 mixing ratios between 2013 and 2015 at GIC3 with the help of co-located observations of 222Rn concentrations, modelled 222Rn fluxes and modelled planetary boundary layer heights (PBLHs). Both daily and seasonal changes in atmospheric CH4 can be better understood with the help of atmospheric concentrations of 222Rn (and the corresponding fluxes). On a daily timescale, the variation in the PBLH is the main driver for 222Rn and CH4 variability while, on monthly timescales, their atmospheric variability seems to depend on emission changes. To understand (changing) CH4 emissions, nocturnal fluxes of CH4 were estimated using two methods: the radon tracer method (RTM) and a method based on the EDGARv4.2 bottom-up emission inventory, both using FLEXPARTv9.0.2 footprints. The mean value of RTM-based methane fluxes (FR_CH4) is 0.11 mg CH4 m-2 h-1 with a standard deviation of 0.09 or 0.29 mg CH4 m-2 h-1 with a standard deviation of 0.23 mg CH4 m-2 h-1 when using a rescaled 222Rn map (FR_CH4_rescale). For our observational period, the mean value of methane fluxes based on the bottom-up inventory (FE_CH4) is 0.33 mg CH4 m-2 h-1 with a standard deviation of 0.08 mg CH4 m-2 h-1. Monthly CH4 fluxes based on RTM (both FR_CH4 and FR_CH4_rescale) show a seasonality which is not observed for monthly FE_CH4 fluxes. During January-May, RTM-based CH4 fluxes present mean values 25 % lower than during June-December. This seasonal increase in methane fluxes calculated by RTM for the GIC3 area appears to coincide with the arrival of transhumant livestock at GIC3 in the second half of the year.

  12. Land-Atmosphere Feedback Experiment (LAFE) Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    Wulfmeyer, Volker [University of Hohenheim; Turner, David [NOAA National Severe Storms Laboratory

    2016-07-01

    The Land-Atmosphere Feedback Experiment (LAFE; pronounced “la-fey”) deploys several state-of-the-art scanning lidar and remote sensing systems to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site. These instruments will augment the ARM instrument suite in order to collect a data set for studying feedback processes between the land surface and the atmosphere. The novel synergy of remote-sensing systems will be applied for simultaneous measurements of land-surface fluxes and horizontal and vertical transport processes in the atmospheric convective boundary layer (CBL). The impact of spatial inhomogeneities of the soil-vegetation continuum on land-surface-atmosphere (LSA) feedback will be studied using the scanning capability of the instrumentation. The time period of the observations is August 2017, because large differences in surface fluxes between different fields and bare soil can be observed, e.g., pastures versus fields where the wheat has already been harvested. The remote sensing system synergy will consist of three components: 1) The SGP water vapor and temperature Raman lidar (SRL), the SGP Doppler lidar (SDL), and the National Center for Atmospheric Research (NCAR) water vapor differential absorption lidar (DIAL) (NDIAL) mainly in vertical staring modes to measure mean profiles and gradients of moisture, temperature, and horizontal wind. They will also measure profiles of higher-order turbulent moments in the water vapor and wind fields and profiles of the latent heat flux. 2) A novel scanning lidar system synergy consisting of the National Oceanic and Atmospheric Administration (NOAA) High-Resolution Doppler lidar (HRDL), the University of Hohenheim (UHOH) water-vapor differential absorption lidar (UDIAL), and the UHOH temperature Raman lidar (URL). These systems will perform coordinated range-height indicator (RHI) scans from just above the canopy level to the

  13. Diffusion from a Ground Level Point Source Experiment with Thermoluminescence Dosimeters and Kr 85 as Tracer Substance

    Energy Technology Data Exchange (ETDEWEB)

    Gyllander, Ch; Hollman, S; Widemo, U

    1969-04-15

    Within the framework of the IRIS-project (Iodine Research in Safety Project) an experiment to study diffusion at near-ground level was carried out on 19 December 1967 using {sup 85}Kr as the tracer element. The object of the experiment was a) to test the method using |3-sensitive thermoluminescence dosimeters under actual field conditions. b) to study the initial dilution from a ground level point source. The test area chosen was the Tranvik valley just south of Trobbofjaerden, an inland bay of the Baltic. Dose distributions have been studied at two sections, 50 and 200 m respectively, from the release point. At each level various dispersion parameters have been experimentally determined and their conformity to normal distribution have been calculated. Dilution factors valid for the centre of the plume are related to the values reported in the literature. The experiment was made under ideal weather conditions above snow-free ground. Results of the next experiment, a point release at ground level from a building at Studsvik, are expected to yield valuable information concerning the effect of buildings on the diffusion pattern.

  14. Diffusion from a Ground Level Point Source Experiment with Thermoluminescence Dosimeters and Kr 85 as Tracer Substance

    International Nuclear Information System (INIS)

    Gyllander, Ch.; Hollman, S.; Widemo, U.

    1969-04-01

    Within the framework of the IRIS-project (Iodine Research in Safety Project) an experiment to study diffusion at near-ground level was carried out on 19 December 1967 using 85 Kr as the tracer element. The object of the experiment was a) to test the method using |3-sensitive thermoluminescence dosimeters under actual field conditions. b) to study the initial dilution from a ground level point source. The test area chosen was the Tranvik valley just south of Trobbofjaerden, an inland bay of the Baltic. Dose distributions have been studied at two sections, 50 and 200 m respectively, from the release point. At each level various dispersion parameters have been experimentally determined and their conformity to normal distribution have been calculated. Dilution factors valid for the centre of the plume are related to the values reported in the literature. The experiment was made under ideal weather conditions above snow-free ground. Results of the next experiment, a point release at ground level from a building at Studsvik, are expected to yield valuable information concerning the effect of buildings on the diffusion pattern

  15. A mathematical model for the design and interpretation of tracer experiments intended to measure the T90 in estuarine coastal waters

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2006-07-01

    In highly stratified estuarine waters, with significant sediment loads, it is fairly difficult to predict the T90 , the time scale that characterizes the bacterial inactivation or death, using mathematical formulae, so that suitable experiments must be done using tracers to measure physical dilution and microbiological methods to measure bacterial disappearance or inactivation. The location and characteristics of a second sewage out fall for the city of Montevideo is being determined. In this framework, several experiments with tracers were done to measure the self-purifying capacity of the coastal waters at the selected site. Due to the difficulties in the design and interpretation of the measurements, special mathematical models were constructed and applied to help in obtaining a deeper understanding of the complex advection-dispersion-inactivation processes. In this report the construction and the solution of the equations of an analytical model that guided all the subsequent modelling activities is described. The tracer and the bacteria fields are obtained as products of a function of time and the horizontal coordinates by a series of decaying exponential functions of time weighted by functions of depth. The quotient between the bacteria concentration and the tracer concentration, that is commonly used to determine a global value of T90 , taking suitable average values after a long enough transient, is studied. A procedure that may be used to summarize the field of local inactivation times by a few parameters, determined by tracer experiments and microbiological measurements, is discussed. A half-empirical correlation formula between the T90 parameter and the main variables of the body of receiving waters is suggested from the results of tracer experiments and other sources of information. The advantages and limitations of the modelling approach used in this case are assessed and some possible improvements are briefly outlined

  16. A mathematical model for the design and interpretation of tracer experiments intended to measure the T90 in estuarine coastal waters

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2006-03-01

    In highly stratified estuarine waters, with significant sediment loads, it is fairly difficult to predict the T90, the time scale that characterizes the bacterial inactivation or death, using mathematical formulae, so that suitable experiments must be done using tracers to measure physical dilution and microbiological methods to measure bacterial disappearance or inactivation. The location and characteristics of a second sewage outfall for the city of Montevideo is being determined. In this framework, several experiments with tracers were done to measure the self-purifying capacity of the coastal waters at the selected site. Due to the difficulties in the design and interpretation of the measurements, special mathematical models were constructed and applied to help in obtaining a deeper understanding of the complex advection-dispersion-inactivation processes. In this report the construction and the solution of the equations of an analytical model that guided all the subsequent modelling activities is described. The tracer and the bacteria fields are obtained as products of a function of time and the horizontal coordinates by a series of decaying exponential functions of time weighted by functions of depth. The quotient between the bacteria concentration and the tracer concentration, that is commonly used to determine a global value of T90 , taking suitable average values after a long enough transient, is studied. A procedure that may be used to summarize the field of local inactivation times by a few parameters, determined by tracer experiments and microbiological measurements, is discussed. A half-empirical correlation formula between the T90 parameter and the main variables of the body of receiving waters is suggested from the results of tracer experiments and other sources of information. The advantages and limitations of the modelling approach used in this case are assessed and some possible improvements are briefly outlined

  17. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    NARCIS (Netherlands)

    Bühring, S.I.; Ehrenhauss, S.; Kamp, A.; Moodley, L.; Prof. Witte, U.

    2006-01-01

    In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we

  18. Experiments of reconstructing discrete atmospheric dynamic models from data (I)

    Science.gov (United States)

    Lin, Zhenshan; Zhu, Yanyu; Deng, Ziwang

    1995-03-01

    In this paper, we give some experimental results of our study in reconstructing discrete atmospheric dynamic models from data. After a great deal of numerical experiments, we found that the logistic map, x n + 1 = 1- μx {2/n}, could be used in monthly mean temperature prediction when it was approaching the chaotic region, and its predictive results were in reverse states to the practical data. This means that the nonlinear developing behavior of the monthly mean temperature system is bifurcating back into the critical chaotic states from the chaotic ones.

  19. Assessing the Tangent Linear Behaviour of Common Tracer Transport Schemes and Their Use in a Linearised Atmospheric General Circulation Model

    Science.gov (United States)

    Holdaway, Daniel; Kent, James

    2015-01-01

    The linearity of a selection of common advection schemes is tested and examined with a view to their use in the tangent linear and adjoint versions of an atmospheric general circulation model. The schemes are tested within a simple offline one-dimensional periodic domain as well as using a simplified and complete configuration of the linearised version of NASA's Goddard Earth Observing System version 5 (GEOS-5). All schemes which prevent the development of negative values and preserve the shape of the solution are confirmed to have nonlinear behaviour. The piecewise parabolic method (PPM) with certain flux limiters, including that used by default in GEOS-5, is found to support linear growth near the shocks. This property can cause the rapid development of unrealistically large perturbations within the tangent linear and adjoint models. It is shown that these schemes with flux limiters should not be used within the linearised version of a transport scheme. The results from tests using GEOS-5 show that the current default scheme (a version of PPM) is not suitable for the tangent linear and adjoint model, and that using a linear third-order scheme for the linearised model produces better behaviour. Using the third-order scheme for the linearised model improves the correlations between the linear and non-linear perturbation trajectories for cloud liquid water and cloud liquid ice in GEOS-5.

  20. Atmospheric natural disasters in Serbia: Management experience and economic effects

    Directory of Open Access Journals (Sweden)

    Nikolić Jugoslav

    2013-01-01

    Full Text Available Natural disasters occur as a result of an action of natural forces and represent limitations in spatial planning and efficient spatial development, with different consequences in terms of scope on humans, living things and tangible property. Consequences can be ecological, economic, in terms of health, demographic, social, psychological, etc. Weather modification management involves policies, methods, techniques and technologies that affect atmospheric features in order to make atmospheric water useful for humans, while eliminating its negative effects. Highly significant risk of natural disasters in Serbia is related to hailstorm disasters and droughts as atmospheric elementary disasters. The goal of this paper is to present certain methodologies and experience in Serbia in the weather modification management, mainly in the hailstorm processes. This paper provides analysis and critical review of the methodology of an action, with the analysis of the economic benefits. Cost-benefit analysis of a hail suppression project in Serbia was performed. The results point to the economic justification of some aspects of artificial influence on weather disasters.

  1. sup 26 Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi

    1990-12-01

    Accelerator mass spectrometry (AMS) was applied for {sup 26}Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using {sup 26}Al as a tracer. When {sup 26}Al was intraperitoneally injected into rats, a considerable amount of {sup 26}Al was incorporated into the cerebrum after 5-35 days of the injection. (author).

  2. Tracers and tracing methods

    International Nuclear Information System (INIS)

    Leclerc, J.P.

    2001-01-01

    The first international congress on 'Tracers and tracing methods' took place in Nancy in May 2001. The objective of this second congress was to present the current status and trends on tracing methods and their applications. It has given the opportunity to people from different fields to exchange scientific information and knowledge about tracer methodologies and applications. The target participants were the researchers, engineers and technologists of various industrial and research sectors: chemical engineering, environment, food engineering, bio-engineering, geology, hydrology, civil engineering, iron and steel production... Two sessions have been planned to cover both fundamental and industrial aspects: 1)fundamental development (tomography, tracer camera visualization and particles tracking; validation of computational fluid dynamics simulations by tracer experiments and numerical residence time distribution; new tracers and detectors or improvement and development of existing tracing methods; data treatments and modeling; reactive tracer experiments and interpretation) 2)industrial applications (geology, hydrogeology and oil field applications; civil engineering, mineral engineering and metallurgy applications; chemical engineering; environment; food engineering and bio-engineering). The program included 5 plenary lectures, 23 oral communications and around 50 posters. Only 9 presentations are interested for the INIS database

  3. Environmental Tracers

    Directory of Open Access Journals (Sweden)

    Trevor Elliot

    2014-10-01

    Full Text Available Environmental tracers continue to provide an important tool for understanding the source, flow and mixing dynamics of water resource systems through their imprint on the system or their sensitivity to alteration within it. However, 60 years or so after the first isotopic tracer studies were applied to hydrology, the use of isotopes and other environmental tracers are still not routinely necessarily applied in hydrogeological and water resources investigations where appropriate. There is therefore a continuing need to promote their use for developing sustainable management policies for the protection of water resources and the aquatic environment. This Special Issue focuses on the robustness or fitness-for-purpose of the application and use of environmental tracers in addressing problems and opportunities scientifically, to promote their wider use and to address substantive issues of vulnerability, sustainability, and uncertainty in (groundwater resources systems and their management.

  4. Assessment of key transport parameters in a karst system under different dynamic conditions based on tracer experiments: the Jeita karst system, Lebanon

    Science.gov (United States)

    Doummar, Joanna; Margane, Armin; Geyer, Tobias; Sauter, Martin

    2018-03-01

    Artificial tracer experiments were conducted in the mature karst system of Jeita (Lebanon) under various flow conditions using surface and subsurface tracer injection points, to determine the variation of transport parameters (attenuation of peak concentration, velocity, transit times, dispersivity, and proportion of immobile and mobile regions) along fast and slow flow pathways. Tracer breakthrough curves (TBCs) observed at the karst spring were interpreted using a two-region nonequilibrium approach (2RNEM) to account for the skewness in the TBCs' long tailings. The conduit test results revealed a discharge threshold in the system dynamics, beyond which the transport parameters vary significantly. The polynomial relationship between transport velocity and discharge can be related to the variation of the conduit's cross-sectional area. Longitudinal dispersivity in the conduit system is not a constant value (α = 7-10 m) and decreases linearly with increasing flow rate because of dilution effects. Additionally, the proportion of immobile regions (arising from conduit irregularities) increases with decreasing water level in the conduit system. From tracer tests with injection at the surface, longitudinal dispersivity values are found to be large (8-27 m). The tailing observed in some TBCs is generated in the unsaturated zone before the tracer actually arrives at the major subsurface conduit draining the system. This work allows the estimation and prediction of the key transport parameters in karst aquifers. It shows that these parameters vary with time and flow dynamics, and they reflect the geometry of the flow pathway and the origin of infiltrating (potentially contaminated) recharge.

  5. Enhanced benthic activity in sandy sublittoral sediments: Evidence from 13C tracer experiments

    DEFF Research Database (Denmark)

    Bühring, Solveig I.; Ehrenhauss, Sandra; Kamp, Anja

    2006-01-01

    In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight (southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we...... investigated the pathway of settling particulate organic carbon through the benthic food web. The diatom Ditylum brightwellii was labelled with the stable carbon isotope 13C and injected into incubation chambers. On-board incubations lasted 12, 30 and 132 h, while the in situ experiment was incubated for 32 h....... The study revealed a stepwise short-term processing of a phytoplankton bloom settling on a sandy sediment. After the 12 h incubation, the largest fraction of recovered carbon was in the bacteria (62%), but after longer incubation times (30 and 32 h in situ) the macrofauna gained more importance (15 and 48...

  6. Radon as a tracer of atmospheric influences on traffic-related air pollution in a small inland city

    Directory of Open Access Journals (Sweden)

    Alastair G. Williams

    2016-09-01

    Full Text Available One year of radon, benzene and carbon monoxide (CO concentrations were analysed to characterise the combined influences of variations in traffic density and meteorological conditions on urban air quality in Bern, Switzerland. A recently developed radon-based stability categorisation technique was adapted to account for seasonal changes in day length and reduction in the local radon flux due to snow/ice cover and high soil moisture. Diurnal pollutant cycles were shown to result from an interplay between variations in surface emissions (traffic density, the depth of the nocturnal atmospheric mixing layer (dilution and local horizontal advection of cleaner air from outside the central urban/industrial area of this small compact inland city. Substantial seasonal differences in the timing and duration of peak pollutant concentrations in the diurnal cycle were attributable to changes in day length and the switching to/from daylight-savings time in relation to traffic patterns. In summer, average peak benzene concentrations (0.62 ppb occurred in the morning and remained above 0.5 ppb for 2 hours, whereas in winter average peak concentrations (0.85 ppb occurred in the evening and remained above 0.5 ppb for 9 hours. Under stable conditions in winter, average peak benzene concentrations (1.1 ppb were 120% higher than for well-mixed conditions (0.5 ppb. By comparison, summertime peak benzene concentrations increased by 53% from well-mixed (0.45 ppb to stable nocturnal conditions (0.7 ppb. An idealised box model incorporating a simple advection term was used to derive a nocturnal mixing length scale based on radon, and then inverted to simulate diurnal benzene and CO emission variations at the city centre. This method effectively removes the influences of local horizontal advection and stability-related vertical dilution from the emissions signal, enabling a direct comparison with hourly traffic density. With the advection term calibrated appropriately

  7. Development of radioisotope tracer technology

    International Nuclear Information System (INIS)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee; Park, Soon Chul; Lim, Dong Soon; Kim, Jae Ho; Lee, Jae Choon; Lee, Doo Sung; Cho, Yong Suk; Shin, Sung Kuan

    2000-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and to build a strong tracer group to support the local industries. In relation to the tracer technology in 1999, experiments to estimate the efficiencies of a sludge digester of a waste water treatment plant and a submerged biological reactor of a dye industry were conducted. As a result, the tracer technology for optimization of facilities related to wastewater treatment has been developed and is believed to contribute to improve their operation efficiency. The quantification of the experimental result was attempted to improve the confidence of tracer technology by ECRIN program which basically uses the MCNP simulation principle. Using thin layer activation technique, wear of tappet shim was estimated. Thin layer surface of a tappet shim was irradiated by proton beam and the correlation between the measured activity loss and the amount of wear was established. The equipment was developed to adjust the energy of proton which collides with the surface of tappet. The tracer project team has participated into the tracer test for estimating the efficiency of RFCC system in SK cooperation. From the experiment the tracer team has obtained the primary elements to be considered for judging the efficiency of RFCC unit. By developing the tracer techniques to test huge industrial units like RFCC, the tracer team will be able to support the local industries that require technical services to solve any urgent trouble. (author)

  8. Plume dispersion and deposition processes of tracer gas and aerosols in short-distance experiments

    International Nuclear Information System (INIS)

    Taeschner, M.; Bunnenberg, C.

    1988-01-01

    Data used in this paper were extracted from field experiments carried out in France and Canada to study the pathway of elementary tritium after possible emissions from future fusion reactors and from short-range experiments with nutrient aerosols performed in a German forest in view of a therapy of damaged coniferous trees by foliar nutrition. Comparisons of dispersion parameters evaluated from the tritium field experiments show that in the case of the 30-min release the variations of the wind directions represent the dominant mechanism of lateral plume dispersion under unstable weather conditions. This corresponds with the observation that for the short 2-min emission the plume remains more concentrated during propagation, and the small lateral dispersion parameters typical for stable conditions have to be applied. The investigations on the dispersion of aerosol plumes into a forest boundary layer show that the Gaussian plume model can be modified by a windspeed factor to be valid for predictions on aerosol concentrations and depositions even in a structured topography like a forest

  9. LATTICE: The Lower ATmosphere-Thermosphere-Ionosphere Coupling Experiment

    Science.gov (United States)

    Mlynczak, M. G.; Yee, J. H.

    2017-12-01

    We present the Lower Atmosphere-Thermosphere-Ionosphere Coupling Experiment (LATTICE), which is a candidate mission for proposal to a future NASA Announcement of Opportunity. LATTICE will make the first consistent measurements of global kinetic temperature from the tropopause up to at least 160 km, along with global vector winds from 100 to 160 km at all local times. LATTICE thus provides, for the first time, a consistent picture of the coupling of the terrestrial lower atmosphere to the thermosphere-ionosphere system, which is a major scientific goal outlined in the 2012 Heliophysics Decadal Survey. The core instruments on LATTICE are the Terahertz Limb Sounder (TLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry-II (SABER-II) instrument. The TLS instrument measures the 147 µm (2.04 THz) fine structure line of atomic oxygen. From these measurements TLS will provide kinetic temperature, atomic oxygen density, and vector wind from 100 to at least 160 km altitude. SABER-II is an infrared radiometer and is optically identical to the legacy SABER instrument on the current TIMED satellite. SABER-II is half the mass, half the power, and one-third the volume of the legacy instrument, and expects the same radiometric performance. SABER-II will again measure kinetic temperature from 15 to 110 km and will make measurements of key parameters in the thermosphere-ionosphere system including NO+, the green line and red line emissions, as well as continuing legacy measurements of ozone, water vapor, atomic oxygen, and atomic hydrogen in the mesosphere and lower thermosphere. We will describe the LATTICE mission in detail including other potential instruments for diagnosing thermospheric composition and high latitude energy inputs, and for measuring solar ultraviolet irradiance.

  10. Accumulation of methylmercury in rice and flooded soil in experiments with an enriched isotopic Hg(II) tracer

    Science.gov (United States)

    Strickman, R. J.; Mitchell, C. P. J.

    2015-12-01

    Methylmercury (MeHg) is a neurotoxin produced in anoxic aquatic sediments. Numerous factors, including the presence of aquatic plants, alter the biogeochemistry of sediments, affecting the rate at which microorganisms transform bioavailable inorganic Hg (IHg) to MeHg. Methylmercury produced in flooded paddy soils and its transfer into rice has become an important dietary consideration. An improved understanding of how MeHg reaches the grain and the extent to which rice alters MeHg production in rhizosphere sediments could help to inform rice cultivation practices. We conducted a controlled greenhouse experiment with thirty rice plants grown in individual, flooded pots amended with enriched 200Hg. Unvegetated controls were maintained under identical conditions. At three plant growth stages (vegetative growth, flowering, and grain maturity), ten plants were sacrificed and samples collected from soil, roots, straw, panicle, and grain of vegetated and unvegetated pots, and assessed for MeHg and THg concentrations. We observed consistent ratios between ambient and tracer MeHg between soils (0.36 ±0.04 — 0.44 ± 0.09) and plant compartments (0.23 ± 0.07 -0.34 ± 0.05) indicating that plant MeHg contamination originates in the soil rather than in planta methylation. The majority of this MeHg was absorbed between the tillering (4.48 ± 2.38 ng/plant) and flowering (8.43 ± 5.12 ng/pl) phases, with a subsequent decline at maturity (2.87 ± 1.23 ng/pl) only partly explained by translocation to the developing grain, indicating that MeHg was demethylated in planta. In contrast, IHg was absorbed from both soil and air, as evidenced by the higher ambient IHg concentrations compared to tracer (3.76 ± 1.19 vs. 0.27 ± 0.40 ng/g). Surprisingly, MeHg accumulation was significantly (p= 0.042-- 0.003) lower in vegetated vs. unvegetated sediments at flowering (1.41 ± 0.26 vs. 1.57 ± 0.23) and maturity (1.27 ± 0.22 vs. 1.71 ± 0.25), suggesting that plant exudates bound Hg

  11. Nitrous oxide as a dynamical tracer in the 1987 Airborne Antarctic Ozone Experiment

    Science.gov (United States)

    Loewenstein, M.; Podolske, J. R.; Chan, K. R.; Strahan, S. E.

    1989-01-01

    In situ N2O measurements were made using an airborne tunable laser absorption spectrometer (ATLAS) on 12 flights into the Antarctic vortex, as well as on five transit flights outside the vortex region in August and September 1987, as part of the Airborne Antartic Ozone Experiment. Vertical profiles of N2O were obtained within the vortex on most of these flights and were obtained outside the vortex on several occasions. Flights into the vortex region show N2O decreasing southward between 53 and 72 S latitude on constant potential temperature surfaces in the lower stratosphere. The data lead to two important conclusions about the vortex region: (1) the lower stratosphere in August/September 1987 was occupied by 'old' air, which had subsided several kilometers during polar winter; (2) the N2O profile in the vortex was in an approximately steady state in August/September 1987, which indicates that the spring upwelling, suggested by several theories, did not occur.

  12. Hydrologic Process Regularization for Improved Geoelectrical Monitoring of a Lab-Scale Saline Tracer Experiment

    Science.gov (United States)

    Oware, E. K.; Moysey, S. M.

    2016-12-01

    Regularization stabilizes the geophysical imaging problem resulting from sparse and noisy measurements that render solutions unstable and non-unique. Conventional regularization constraints are, however, independent of the physics of the underlying process and often produce smoothed-out tomograms with mass underestimation. Cascaded time-lapse (CTL) is a widely used reconstruction technique for monitoring wherein a tomogram obtained from the background dataset is employed as starting model for the inversion of subsequent time-lapse datasets. In contrast, a proper orthogonal decomposition (POD)-constrained inversion framework enforces physics-based regularization based upon prior understanding of the expected evolution of state variables. The physics-based constraints are represented in the form of POD basis vectors. The basis vectors are constructed from numerically generated training images (TIs) that mimic the desired process. The target can be reconstructed from a small number of selected basis vectors, hence, there is a reduction in the number of inversion parameters compared to the full dimensional space. The inversion involves finding the optimal combination of the selected basis vectors conditioned on the geophysical measurements. We apply the algorithm to 2-D lab-scale saline transport experiments with electrical resistivity (ER) monitoring. We consider two transport scenarios with one and two mass injection points evolving into unimodal and bimodal plume morphologies, respectively. The unimodal plume is consistent with the assumptions underlying the generation of the TIs, whereas bimodality in plume morphology was not conceptualized. We compare difference tomograms retrieved from POD with those obtained from CTL. Qualitative comparisons of the difference tomograms with images of their corresponding dye plumes suggest that POD recovered more compact plumes in contrast to those of CTL. While mass recovery generally deteriorated with increasing number of time

  13. TRACER: an ‘eye-opener’ to the patient experience across the transition of care in an internal medicine resident program

    Directory of Open Access Journals (Sweden)

    Lauren B. Meade

    2015-04-01

    Full Text Available Background: A safe patient transition requires a complex set of physician skills within the interprofessional practice. Objective: To evaluate a rotation which applies self-reflection and workplace learning in a TRAnsition of CarE Rotation (TRACER for internal medicine (IM residents. TRACER is a 2-week required IM resident rotation where trainees join a ward team as a quality officer and follow patients into postacute care. Methods: In 2010, residents participated in semistructured, one-on-one interviews as part of ongoing program evaluation. They were asked what they had learned on TRACER, the year prior, and how they used those skills in their practice. Using transcripts, the authors reviewed and coded each transcript to develop themes. Results: Five themes emerged from a qualitative, grounded theory analysis: seeing things from the other side, the ‘ah ha’ moment of fragmented care, team collaboration including understanding nursing scope of practice in different settings, patient understanding, and passing the learning on. TRACER gives residents a moment to breathe and open their eyes to the interprofessional practice setting and the patient's experience of care in transition. Conclusions: Residents learn about transitions of care through self-reflection. This learning is sustained over time and is valued enough to teach to their junior colleagues.

  14. Ensemble-based simultaneous emission estimates and improved forecast of radioactive pollution from nuclear power plant accidents: application to ETEX tracer experiment

    International Nuclear Information System (INIS)

    Zhang, X.L.; Li, Q.B.; Su, G.F.; Yuan, M.Q.

    2015-01-01

    The accidental release of radioactive materials from nuclear power plant leads to radioactive pollution. We apply an augmented ensemble Kalman filter (EnKF) with a chemical transport model to jointly estimate the emissions of Perfluoromethylcyclohexane (PMCH), a tracer substitute for radionuclides, from a point source during the European Tracer Experiment, and to improve the forecast of its dispersion downwind. We perturb wind fields to account for meteorological uncertainties. We expand the state vector of PMCH concentrations through continuously adding an a priori emission rate for each succeeding assimilation cycle. We adopt a time-correlated red noise to simulate the temporal emission fluctuation. The improved EnKF system rapidly updates (and reduces) the excessively large initial first-guess emissions, thereby significantly improves subsequent forecasts (r = 0.83, p < 0.001). It retrieves 94% of the total PMCH released and substantially reduces transport error (>80% average reduction of the normalized mean square error). - Highlights: • EnKF is augmented for estimating emission and improving dispersion forecast. • The improved system retrieves 94% of the actual total tracer release in ETEX. • The system substantially improves the 3-h forecast of the tracer dispersion. • The method is robust and insensitive to the first-guess emissions. • The meteorological uncertainties exert strong influence on the performance

  15. History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE

    Directory of Open Access Journals (Sweden)

    R. G. Prinn

    2018-06-01

    Full Text Available We present the organization, instrumentation, datasets, data interpretation, modeling, and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment. AGAGE is distinguished by its capability to measure globally, at high frequency, and at multiple sites all the important species in the Montreal Protocol and all the important non-carbon-dioxide (non-CO2 gases assessed by the Intergovernmental Panel on Climate Change (CO2 is also measured at several sites. The scientific objectives of AGAGE are important in furthering our understanding of global chemical and climatic phenomena. They are the following: (1 to accurately measure the temporal and spatial distributions of anthropogenic gases that contribute the majority of reactive halogen to the stratosphere and/or are strong infrared absorbers (chlorocarbons, chlorofluorocarbons – CFCs, bromocarbons, hydrochlorofluorocarbons – HCFCs, hydrofluorocarbons – HFCs and polyfluorinated compounds (perfluorocarbons – PFCs, nitrogen trifluoride – NF3, sulfuryl fluoride – SO2F2, and sulfur hexafluoride – SF6 and use these measurements to determine the global rates of their emission and/or destruction (i.e., lifetimes; (2 to accurately measure the global distributions and temporal behaviors and determine the sources and sinks of non-CO2 biogenic–anthropogenic gases important to climate change and/or ozone depletion (methane – CH4, nitrous oxide – N2O, carbon monoxide – CO, molecular hydrogen – H2, methyl chloride – CH3Cl, and methyl bromide – CH3Br; (3 to identify new long-lived greenhouse and ozone-depleting gases (e.g., SO2F2, NF3, heavy PFCs (C4F10, C5F12, C6F14, C7F16, and C8F18 and hydrofluoroolefins (HFOs; e.g., CH2  =  CFCF3 have been identified in AGAGE, initiate the real-time monitoring of these new gases, and reconstruct their past histories from AGAGE, air archive, and firn air measurements; (4

  16. Research Experiences for Undergraduates in Estuarine and Atmospheric Processes

    Science.gov (United States)

    Aller, J. Y.

    2009-12-01

    Our program in the School of Marine and Atmospheric Sciences at Stony Brook University is unique in emphasizing the interdisciplinary study of coastal ocean and atmospheric processes. We attract a large number of both male and female undergraduate applicants representing diverse ethnic groups from across the country. Many are multi-discipline majors merging geology, biology, chemistry, or physics with engineering, and/or mathematics and welcome the opportunity to combine their academic training to examine environmental problems. Our goal is a program reflective of today’s world and environmental challenges, one that provides a ‘hands-on’ research experience which illustrates the usefulness of scientific research for understanding real-world problems or phenomena, and one in which students are challenged to apply their academic backgrounds to develop intuition about natural systems and processes. Projects this past summer focused on assessing climate change and its effects on coastal environments and processes. Projects addressed the implications of a changing global climate over the next 50 years on hydrologic cycles and coastal environments like barrier islands and beaches, on seasonal weather conditions and extreme events, on aerosols and the Earth’s radiative balance, and on aquatic habitats and biota. Collaborative field and laboratory or computer-based projects involving two or three REU students, graduate students, and several mentors, enable undergraduate students appreciate the importance of teamwork in addressing specific scientific questions or gaining maximum insight into a particular phenomenon or process. We believe that our approach allows students to understand what their role will be as scientists in the next phase of our earth’s evolution.

  17. Models for tracer flow

    International Nuclear Information System (INIS)

    Zuber, A.

    1983-01-01

    A review and discussion is given of mathematical models used for interpretation of tracer experiments in hydrology. For dispersion model, different initial and boundary conditions are related to different injection and detection modes. Examples of applications of various models are described and commented. (author)

  18. Gas transport below artificial recharge ponds: insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment.

    Science.gov (United States)

    Clark, Jordan F; Hudson, G Bryant; Avisar, Dror

    2005-06-01

    A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.

  19. 13C-Tracer Experiments in DIII-D Preliminary to Thermal Oxidation Experiments to Understand Tritium Recovery in DIII-D, JET, C-Mod, and MAST

    International Nuclear Information System (INIS)

    Stangeby, P.; Allen, S.; Bekris, N.; Brooks, N.; Christie, K.; Chrobak, C.; Coad, J.; Counsell, G.; Davis, J.; Elder, J.; Fenstermacher, M.; Groth, M.; Haasz, A.; Likonen, J.; Lipschultz, B.; McLean, A.; Philipps, V.; Porter, G.; Rudakov, D.; Shea, J.; Wampler, W.; Watkins, J.; West, W.; Whyte, D.

    2006-01-01

    Retention of tritium in carbon co-deposits is a serious concern for ITER. Developing a reliable in-situ removal method of the co-deposited tritium would allow the use of carbon plasma-facing components which have proven reliable in high heat flux conditions and compatible with high performance plasmas. Thermal oxidation is a potential solution, capable of reaching even hidden locations. It is necessary to establish the least severe conditions to achieve adequate tritium recovery, minimizing damage and reconditioning time. The first step in this multi-machine project is 13 C-tracer experiments in DIII-D, JET, C-Mod and MAST. In DIII-D and JET, 13 CH 4 has been (and in C-Mod and MAST, will be) injected toroidally symmetrically, facilitating quantification and interpretation of the results. Tiles have been removed, analyzed for 13 C content and will next be evaluated in a thermal oxidation test facility in Toronto with regard to the ability of different severities of oxidation exposure to remove the different types of (known and measured) 13 C co-deposit. Removal of D/T from B on Mo tiles from C-Mod will also be tested. OEDGE interpretive code analysis of the 13 C deposition patterns is used to generate the understanding needed to apply findings to ITER. First results are reported here for the 13 C injection experiments IN DIII-D

  20. Anisotropy, reversibility and scale dependence of transport properties in single fracture and fractured zone - Non-sorbing tracer experiment at the Kamaishi mine

    International Nuclear Information System (INIS)

    Sawada, Atushi; Uchida, Masahiro; Shimo, Michito; Yamamoto, Hajime; Takahara, Hiroyuki; Doe, T.W.

    2001-01-01

    A comprehensive set of the non-sorbing tracer experiments were run in the granodiorite of the Kamaishi mine located in the northern part of the main island of Japan-Honshu. A detailed geo-hydraulic investigation was carried out prior to performing the tracer migration experiments. The authors conducted a detailed but simple investigation in order to understand the spatial distribution of conductive fractures and the pressure field. Seven boreholes were drilled in the test area of which dimension is approximately 80 meters by 60 meters, revealing hydraulic compartmentalization and a heterogeneous distribution of conductive features. Central three boreholes which are approx. 2 to 4 meters apart form a triangle array. After identifying two hydraulically isolated fractures and one fractured zone, a comprehensive non-sorbing tracer experiments were conducted. Four different dipole fields were used to study the heterogeneity within a fracture. Firstly, anisotropy was studied using the central borehole array of three boreholes and changing injection/withdrawal wells. Secondly, dipole ratio was varied to study how prume spread could affect the result. Thirdly, reversibility was studied by switching injection/withdrawal wells. Lastly, scale dependency was studied by using outer boreholes. The tracer breakthrough curves were analyzed by using a streamline, analytical solution and numerical analysis of mass transport. Best-fit calculations of the experimental breakthrough curves were obtained by assigning apertures within the range of 1-10 times the square root of transmissivity and a dispersion length equal to 1/10 of the migration length. Different apertures and dispersion lengths were also interpreted in anisotropy case, reversibility case and scale dependency case. Fractured zone indicated an increased aperture and increased dispersivity

  1. Characteristics and parameters of bed-load movement for multi-bar near-shore zone on the base of tracer field experiments

    International Nuclear Information System (INIS)

    Wierzchnicki, R.

    1997-01-01

    The radiotracer method for field investigation of marine bed sediments in Baltic Sea near-shore zone has been elaborated and successfully used. The artificial sand made of special glass containing Ir-192 and quartz like density has been used as a tracer. The field experiments have been carried out at Coastal Station of the Institute of Hydroengineering in Lubiatowo. The tracer movement has been observed at different weather and wave conditions. On the base of obtained data the next characteristics and parameters of sand transport have been defined and discussed: critical velocities of sand grains; sediment velocities versus the long shore current; thickness of the layer transported; intensity of the transport. For the purpose of coastal engineering practice the global transport intensity in the multi bar-coastal zone conditions has been determined as a function of main parameters describing breaking waves (height and propagation angle)

  2. Deuterium used as artificial tracer in column studies under saturated water flow conditions

    Science.gov (United States)

    Koeniger, P.; Geiges, M.; Leibundgut, Ch.

    2003-04-01

    In contrast to numerous investigations using deuterium as an environmental tracer, hydrological investigations with deuterium-labelled water are rather rare. Currently applications in groundwater studies are restricted due to increasing costs of spiking large water quantities but an application as intelligent tracer might be of advantage especially in combination with other tracers and under distinct environmental conditions. Therefore deuterium was applied as artificial tracer in column experiments that are well proved as a tool to characterise tracer behaviour in recent studies. Deuterium was tested in comparison to the more familiar conservative tracer fluorescein. Varying experimental conditions, e.g. column length (0.5, 1.0, 1.5 m), initial tracer concentration (0.01, 0.02, 0.2 mg) and flow velocity (1.5 to 6.0 m/d) were used to investigate tracer behaviour under saturated water flow conditions. Deuterium was analysed using an H/Device with chrome reduction connected to an isotope ratio mass spectrometer and expressed in relative concentrations [per mill V-SMOW]. Theoretical tracer breakthrough curves were calculated using a one dimensional dispersion model. The results indicate higher mean transport velocities and smaller dispersion for deuterium in all experiments. Due to different molecule properties that also determine the interaction of soil substrate and tracer, deuterium indicates a more conservative transport behaviour. Deuterium is non-toxic, completely soluble, chemically and biologically stable and not subject to light-influenced decay. Furthermore, it shows promise for investigations of water flow in the unsaturated zone, and of interactions of water in soil-plant-atmosphere systems. A further discussion of problems, together with possibilities for applying deuterium as an artificial tracer, will be presented.

  3. Validation of ozone measurements from the Atmospheric Chemistry Experiment (ACE

    Directory of Open Access Journals (Sweden)

    E. Dupuy

    2009-01-01

    Full Text Available This paper presents extensive {bias determination} analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE satellite instruments: the ACE Fourier Transform Spectrometer (ACE-FTS and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO instrument. Here we compare the latest ozone data products from ACE-FTS and ACE-MAESTRO with coincident observations from nearly 20 satellite-borne, airborne, balloon-borne and ground-based instruments, by analysing volume mixing ratio profiles and partial column densities. The ACE-FTS version 2.2 Ozone Update product reports more ozone than most correlative measurements from the upper troposphere to the lower mesosphere. At altitude levels from 16 to 44 km, the average values of the mean relative differences are nearly all within +1 to +8%. At higher altitudes (45–60 km, the ACE-FTS ozone amounts are significantly larger than those of the comparison instruments, with mean relative differences of up to +40% (about +20% on average. For the ACE-MAESTRO version 1.2 ozone data product, mean relative differences are within ±10% (average values within ±6% between 18 and 40 km for both the sunrise and sunset measurements. At higher altitudes (~35–55 km, systematic biases of opposite sign are found between the ACE-MAESTRO sunrise and sunset observations. While ozone amounts derived from the ACE-MAESTRO sunrise occultation data are often smaller than the coincident observations (with mean relative differences down to −10%, the sunset occultation profiles for ACE-MAESTRO show results that are qualitatively similar to ACE-FTS, indicating a large positive bias (mean relative differences within +10 to +30% in the 45–55 km altitude range. In contrast, there is no significant systematic difference in bias found for the ACE-FTS sunrise and sunset measurements.

  4. 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...

  5. A multicomponent tracer field experiment to measure the flow volume, surface area, and rectilinear spacing of fractures away from the wellbore

    Science.gov (United States)

    Cathles, L. M.; Sanford, W. E.; Hawkins, A.; Li, Y. V.

    2017-12-01

    The nature of flow in fractured porous media is important to almost all subsurface processes including oil and gas recovery, contaminant transport and remediation, CO2 sequestration, and geothermal heat extraction. One would like to know, under flowing conditions, the flow volume, surface area, effective aperture, and rectilinear spacing of fractures in a representative volume of rock away from the well bore, but no methods currently allow acquisition of this data. It could, however, be collected by deploying inert tracers with a wide range of aqueous diffusion constants (e.g., rapidly diffusing heat to non-diffusing nanoparticle) in the following fashion: The flow volume is defined by the heated volume measured by resistivity surveys. The fracture volume within this flow volume is indicate by the nanoparticle transit time. The average fracture spacing is indicated by the evolving thermal profile in the monitor and the production wells (measured by fiber optic cable), and by the retention of absorbing tracers. The average fracture aperture is determined by permeability measurements and the average fracture separation. We have proposed a field test to redundantly measure these fracture parameters in the fractured Dakota Sandstone where it approaches the surface in Ft Collins, Colorado. Five 30 m deep wells (an injection, production, and 3 monitor wells) cased to 20 m are proposed. The experiments will involve at least 9 different tracers. The planned field test and its potential significance will be described.

  6. SUMS preliminary design and data analysis development. [shuttle upper atmosphere mass spectrometer experiment

    Science.gov (United States)

    Hinson, E. W.

    1981-01-01

    The preliminary analysis and data analysis system development for the shuttle upper atmosphere mass spectrometer (SUMS) experiment are discussed. The SUMS experiment is designed to provide free stream atmospheric density, pressure, temperature, and mean molecular weight for the high altitude, high Mach number region.

  7. Field measurements of tracer gas transport by barometric pumping

    International Nuclear Information System (INIS)

    Lagus, P.L.; McKinnis, W.B.; Hearst, J.R.; Burkhard, N.R.; Smith, C.F.

    1994-01-01

    Vertical gas motions induced by barometric pressure variations can carry radioactive gases out of the rubblized region produced by an underground nuclear explosion, through overburden rock, into the atmosphere. To better quantify transit time and amount of transport, field experiments were conducted at two sites on Pahute Mesa, Kapelli and Tierra, where radioactive gases had been earlier detected in surface cracks. At each site, two tracer gases were injected into the rubblized chimney 300-400 m beneath the surface and their arrival was monitored by concentration measurements in gas samples extracted from shallow collection holes. The first ''active'' tracer was driven by a large quantity of injected air; the second ''passive'' tracer was introduced with minimal gas drive to observe the natural transport by barometric pumping. Kapelli was injected in the fall of 1990, followed by Tierra in the fall of 1991. Data was collected at both sites through the summer of 1993. At both sites, no surface arrival of tracer was observed during the active phase of the experiment despite the injection of several million cubic feet of air, suggesting that cavity pressurization is likely to induce horizontal transport along high permeability layers rather than vertical transport to the surface. In contrast, the vertical pressure gradients associated with barometric pumping brought both tracers to the surface in comparable concentrations within three months at Kapelli, whereas 15 months elapsed before surface arrival at Tierra. At Kapelli, a quasisteady pumping regime was established, with tracer concentrations in effluent gases 1000 times smaller than concentrations thought to exist in the chimney. Tracer concentrations observed at Tierra were typically an order of magnitude smaller. Comparisons with theoretical calculations suggest that the gases are traveling through ∼1 millimeter vertical fractures spaced 2 to 4 meters apart. 6 refs., 18 figs., 3 tabs

  8. Evidence for substantial forestry canopy processing of nitrogen deposition using isotopic tracer experiments in low deposition conditions

    Science.gov (United States)

    Ferraretto, Daniele; Heal, Kate

    2017-04-01

    Temperate forest ecosystems are significant sinks for nitrogen deposition (Ndep) yielding benefits such as protection of waterbodies from eutrophication and enhanced sequestration of atmospheric CO2. Previous studies have shown evidence of biological nitrification and Ndep processing and retention in forest canopies. However, this was reported only at sites with high environmental or experimentally enhanced rates of Ndep (˜18 kg N ha-1 y-1) and has not yet been demonstrated in low Ndep environments. We have used bulk field hydrochemical measurements and labelled isotopic experiments to assess canopy processing in a lower Ndep environment (˜7 kg N ha-1 year-1) at a Sitka spruce plantation in Perthshire, Scotland, representing the dominant tree species (24%) in woodlands in Great Britain. Analysis of 4.5 years of measured N fluxes in rainfall (RF) and fogwater onto the canopy and throughfall (TF) and stemflow (SF) below the canopy suggests strong transformation and uptake of Ndep in the forest canopy. Annual canopy Ndep uptake was ˜4.7 kg N ha-1 year-1, representing 60-76% of annual Ndep. To validate these plot-scale results and track N uptake within the forest canopy in different seasons, double 15N-labelled NH4NO3 (98%) solution was sprayed in summer and winter onto the canopy of three trees at the measurement site. RF, TF and SF samples have been collected and analysed for 15NH4 and 15NO3. Comparing the amount of labelled N recovered under the sample trees with the measured δ15N signal is expected to provide further evidence of the role of forest canopies in actively processing and retaining atmospheric N deposition.

  9. Evolution of the electrical resistivity anisotropy during saline tracer tests: insights from geoelectrical milli-fluidic experiments

    Science.gov (United States)

    Jougnot, D.; Jimenez-Martinez, J.; Legendre, R.; Le Borgne, T.; Meheust, Y.; Linde, N.

    2017-12-01

    The use of time-lapse electrical resistivity tomography has been largely developed in environmental studies to remotely monitor water saturation and contaminant plumes migration. However, subsurface heterogeneities, and corresponding preferential transport paths, yield a potentially large anisotropy in the electrical properties of the subsurface. In order to study this effect, we have used a newly developed geoelectrical milli-fluidic experimental set-up with a flow cell that contains a 2D porous medium consisting of a single layer of cylindrical solid grains. We performed saline tracer tests under full and partial water saturations in that cell by jointly injecting air and aqueous solutions with different salinities. The flow cell is equipped with four electrodes to measure the bulk electrical resistivity at the cell's scale. The spatial distribution of the water/air phases and the saline solute concentration field in the water phase are captured simultaneously with a high-resolution camera by combining a fluorescent tracer with the saline solute. These data are used to compute the longitudinal and transverse effective electrical resistivity numerically from the measured spatial distributions of the fluid phases and the salinity field. This approach is validated as the computed longitudinal effective resistivities are in good agreement with the laboratory measurements. The anisotropy in electrical resistivity is then inferred from the computed longitudinal and transverse effective resistivities. We find that the spatial distribution of saline tracer, and potentially air phase, drive temporal changes in the effective resistivity through preferential paths or barriers for electrical current at the pore scale. The resulting heterogeneities in the solute concentrations lead to strong anisotropy of the effective bulk electrical resistivity, especially for partially saturated conditions. Therefore, considering the electrical resistivity as a tensor could improve our

  10. Improvement of wind tunnel experiment method for atmospheric diffusion

    International Nuclear Information System (INIS)

    Nakai, Masayuki; Sada, Koichi

    1987-01-01

    A wind direction fluctuation vane was added to CRIEPI's large - scale atmospheric diffusion wind tunnel for the purpose of increasing and controlling turbulence intensity. When the wind direction fluctuation vane was operated lateral plume spread and lateral turbulence intersity became greater than for cases when it was not operated. Use of the vane improved the ability of the wind tunnel to simulate plane spread under natural conditions. (author)

  11. Measurement of Kr-85 and Xe-133 as undisturbed tracers for the representing of atmospheric transport after disposal of radioactivity from nuclear facilities; Messungen von Kr-85 und Xe-133 als ungestoerte Tracer zur Darstellung atmosphaerischer Transportvorgaenge nach Freisetzung von Radioaktivitaet aus kerntechnischen Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G.; Steinkopff, T. [Deutscher Wetterdienst (Germany); Salvamoser, J. [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen (IGU), Woerthsee (Germany)

    2016-07-01

    The Deutscher Wetterdienst (DWD, German Meteorological Service) operates since 1996 a sampling and measurement device for the radioactive rare gases Kr-85 and Xe-133 in Offenbach. These measurements are embedded in the German Measurement and Information System for Monitoring Environmental Radioactivity (Integriertes Mess- und Informationssystem zur Ueberwachung der Radioaktivitaet in der Umwelt, IMIS) [1]. In addition to these measurements the DWD is sampling rare gases in Potsdam and since 2014 in Trier in cooperation with the Bundesamt fuer Strahlenschutz (Federal Office for Radiation Protection, BfS). In the frame of the Global Atmosphere Watch (GAW)-program of the WMO the DWD operated a sampling station at the Zugspitze (Schneefernerhaus) from 1999 to 2005. This location at the Zugspitze is well suited for the observation of long distance transport of Kr-85 in the higher atmosphere. The DWD in Offenbach operates a complex analytical system for the measurement of Kr-85 and Xe-133 since 1998. This system consists of sampling with first enrichment, second enrichment, gas chromatographic separation and preparation of Krypton and Xenon and measurement of Kr-85 and Xe-133. Using the example Fukushima, it is shown, that the radioactive rare gases Kr-85 and Xe-133 are well undisturbed tracers for atmospheric transport in case of a nuclear accident or routine nuclear reprocessing plants. Measurements of Xe-133, I-131, Cs-137 and Kr-85 are correlated with source and atmospheric transport to the sampling sites at Offenbach and Potsdam.

  12. Measurements of atmospheric and gamma rays-balloon experiments at subantartic region

    International Nuclear Information System (INIS)

    Jayanthi, U.B.; Correa, R.V.; Blanco, F.G.

    1986-01-01

    The results of two stratospheric balloon experiments conducted to measure the atmospheric X and gamma rays are presented. These experiments, conducted at Comandante Ferraz base in subantarctic region, have provided the spectrum of ground radioactivity in gamma rays (0.2 to 2.9 MeV) and atmospheric X-ray spectra at different altitudes. We specifically chose to discuss the observed ceiling spectrum of X-rays in the 28 to 180KeV region observed at 7.0 g. cm -2 . We have utilized the data of other experiments with different telescope geometries, to evaluate the builup effects due to cosmic ray secondaries in atmosphere. This behaviour, previoulsy studied for atmospheric gamma rays, permitted to compare the up/down flux rations to explain the observed atmospheric X-ray spectrum. (Author) [pt

  13. Experiments on cylindrically converging blast waves in atmospheric air

    Science.gov (United States)

    Matsuo, Hideo; Nakamura, Yuichi

    1980-06-01

    Cylindrically converging blast waves have been produced in normal atmospheric conditions by the detonation of the explosives, pentaerythritoltetranitrate, (PETN), over cylindrical surfaces. The shocks generated in this way are so strong that the fronts propagating through the air become luminous of themselves. The production and the propagation of the shocks have been monitored with a framing camera and a streak camera, and the time-space relations of the shock propagations have been determined using an electrical ionization probing system. The results have shown that the trajectory of the shock fronts near the axis of the cylinder can be approximately represented by the Guderley's formula.

  14. The Mars Pathfinder atmospheric structure investigation/meteorology (ASI/MET) experiment

    DEFF Research Database (Denmark)

    Schofield, J.T.; Barnes, J.R.; Crisp, D.

    1997-01-01

    The Mars Pathfinder atmospheric structure investigation/meteorology (ASI/MET) experiment measured the vertical density, pressure, and temperature structure of the martian atmosphere from the surface to 160 km, and monitored surface meteorology and climate for 83 sols (1 sol = 1 martian day = 24...

  15. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  16. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Byegaard, J.; Johansson, Henrik; Skaalberg, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    1998-11-01

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na{sup +}, Rb{sup +} and Cs{sup +}) and alkaline earth metals (Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+}), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order Natracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most

  17. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    International Nuclear Information System (INIS)

    Byegaard, J.; Johansson, Henrik; Skaalberg, M.

    1998-11-01

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na + , Rb + and Cs + ) and alkaline earth metals (Ca 2+ , Sr 2+ and Ba 2+ ), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order Na + in the order of (4-30)x10 -6 m 3 /kg and for Cs + in the range of (I-400)x10 -3 m 3 /kg. The variations in sorption coefficients are due to differences in the composition of the geological material, contact time and particle size. Sorption is generally stronger for the Aespoe-diorite than for the fine-grained granite which is explained by the much higher concentration of biotite in Aespoe diorite than in fine-grained granite. In the altered material the biotite has been transformed to chlorite and a lower sorptivity is shown for those material compared to the fresh diorite and granite, respectively. Attempts to explain the sorption and desorption results to a surface sorption - diffusion model are presented. The diffusion results show that the tracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most representative when comparing batch sorption coefficients with sorption coefficients evaluated from the

  18. 15N tracer studies on N supply from different N fertilizer forms and on localization and losses of fertilizer N - pot experiment in Haplic Chernozem

    International Nuclear Information System (INIS)

    Schulz, E.

    1988-01-01

    In a pot experiment with Haplic Chernozem differing in total carbon content (Static Experiment at Lauchstaedt, 1983), studies were made into N supply from various forms of fertilizers and fertilizer N localization in the plant-soil system. In general, the percentage of fertilizer N in the total N amount taken up by maize was very high (60 to 90%). Both the variate difference method and the tracer technique identified almost equal percentages of fertilizer N in plants after application of pig urine and ammonium nitrate. However, mineralization of soil-borne N after application of sugar beet leaves was overestimated when using the variate difference method. There was no evidence of an additional mobilization of soil-borne N due to fertilization (priming effect). (author)

  19. Organic molecular tracers in the atmospheric aerosols from Lumbini, Nepal, in the northern Indo-Gangetic Plain: influence of biomass burning

    Directory of Open Access Journals (Sweden)

    X. Wan

    2017-07-01

    Full Text Available To better understand the characteristics of biomass burning in the northern Indo-Gangetic Plain (IGP, total suspended particles were collected in a rural site, Lumbini, Nepal, during April 2013 to March 2014 and analyzed for the biomass burning tracers (i.e., levoglucosan, mannosan, vanillic acid. The annual average concentration of levoglucosan was 734 ± 1043 ng m−3 with the maximum seasonal mean concentration during post-monsoon season (2206 ± 1753 ng m−3, followed by winter (1161 ± 1347 ng m−3, pre-monsoon (771 ± 524 ng m−3 and minimum concentration during monsoon season (212 ± 279 ng m−3. The other biomass burning tracers (mannosan, galactosan, p-hydroxybenzoic acid, vanillic acid, syringic acid and dehydroabietic acid also showed the similar seasonal variations. There were good correlations among levoglucosan, organic carbon (OC and elemental carbon (EC, indicating significant impact of biomass burning activities on carbonaceous aerosol loading throughout the year in Lumbini area. According to the characteristic ratios, levoglucosan ∕ mannosan (lev ∕ man and syringic acid ∕ vanillic acid (syr ∕ van, we deduced that the high abundances of biomass burning products during non-monsoon seasons were mainly caused by the burning of crop residues and hardwood while the softwood had less contribution. Based on the diagnostic tracer ratio (i.e., lev ∕ OC, the OC derived from biomass burning constituted large fraction of total OC, especially during post-monsoon season. By analyzing the MODIS fire spot product and 5-day air-mass back trajectories, we further demonstrated that organic aerosol composition was not only related to the local agricultural activities and residential biomass usage but also impacted by the regional emissions. During the post-monsoon season, the emissions from rice residue burning in western India and eastern Pakistan could impact particulate

  20. Radioactive tracers in the sea

    International Nuclear Information System (INIS)

    Jenkins, W.J.; Livingston, H.D.

    1980-01-01

    Artificial radionuclides introduced to the oceans during the last four decades have proved invaluable tools for study of many processes in marine water columns and sediments. Both global and close-in fallout of radioactivity from atmospheric nuclear weapons testing have distributed these radionuclides widely, and in amounts sufficient to be useful as tracers. An additional source of considerable significance and tracer potential comes from coastal discharges of European nuclear fuel reprocessing wastes. The nature of these sources, types and amounts of radionuclides introduced and the time histories of their introduction generate a variety of tracer distributions which illuminate a broad spectrum of physical and chemical processes active over a wide range of timescales. Depending on their respective chemistries, artificial radionuclides have been demonstrated to exhibit both conservative and non-conservative properties in the oceans. Some examples are given of the uses made of soluble, conservative tracers for the study of oceanic transport processes and of non-conservative tracers for studies of processes which move them to, and mix them within, marine sediments. Sampling and measurement techniques which have been used in these studies are described

  1. Study of atmospheric aerosols by IBA techniques: The LABEC experience

    Science.gov (United States)

    Lucarelli, F.; Calzolai, G.; Chiari, M.; Nava, S.; Carraresi, L.

    2018-02-01

    At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN (Florence, Italy) an external beam facility is fully dedicated to PIXE-PIGE measurements of the elemental composition of atmospheric aerosols. All the elements with Z > 10 are simultaneously detected by PIXE typically in one minute. This setup allows us an easy automatic positioning, changing and scanning of samples collected by different kinds of devices: long series of daily PM (Particulate Matter) samples can be analysed in short times, as well as size-segregated and high time-resolution aerosol samples. Thanks to the capability of detecting all the crustal elements, PIXE-PIGE analyses are unrivalled in the study of mineral dust: consequently, they are very effective in the study of natural aerosols, like, for example, Saharan dust intrusions. Among the detectable elements there are also important markers of anthropogenic sources, which allow effective source apportionment studies in polluted urban environments using a multivariate method like Positive Matrix Factorization (PMF). Examples regarding recent monitoring campaigns, performed in urban and remote areas, both daily and with high time resolution (hourly samples), as well as with size selection, are presented. The importance of the combined use of the Particle Induced Gamma Ray emission technique (PIGE) and of other complementary (non-nuclear) techniques is highlighted.

  2. Coefficients of tracer transfer through membranes. Pt. 7

    Energy Technology Data Exchange (ETDEWEB)

    Dorabialska, A; Hawlicka, E; Plonka, A [Politechnika Lodzka (Poland)

    1974-01-01

    The doubled value of the tracer transfer coefficient in the self-diffusion process is equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The fundamental phenomenological relation can be deduced for the coefficients of tracer transfer between two phases of electrolyte solutions spearated by a virtual boundary. Indeed, the doubled value of the tracer mobility in the self-diffusion experiment (no concentration gradient of the traced substance) is equal to the sum of the tracer mobilities in the diffusion (tracer movement along with the concentration gradient of the traced substance) and interfusion experiments (tracer movement against the concentration gradient of the traced substance). Thus the doubled value of the tracer transfer coefficient in the self-diffusion process should be equal to the sum of tracer transfer coefficients in the diffusion and interfusion processes. The experimental verification of that fundamental relation is presented.

  3. Atmospheric discharges from nuclear facilities during decommissioning: German experiences

    Energy Technology Data Exchange (ETDEWEB)

    Braun, H.; Goertz, R.; Weil, L.

    1997-08-01

    In Germany, a substantial amount of experience is available with planning, licensing and realization of decommissioning projects. In total, a number of 18 nuclear power plants including prototype facilities as well as 6 research reactors and 3 fuel cycle facilities have been shut down finally and are at different stages of decommissioning. Only recently the final {open_quotes}green field{close_quotes} stage of the Niederaichbach Nuclear Power Plant total dismantlement project has been achieved. From the regulatory point of view, a survey of the decommissioning experience in Germany is presented highlighting the aspects of production and retention of airborne radioactivity. Nuclear air cleaning technology, discharge limits prescribed in licences and actual discharges are presented. As compared to operation, the composition of the discharged radioactivity is different as well as the off-gas discharge rate. In practically all cases, there is no significant amount of short-lived radionuclides. The discussion further includes lessons learned, for example inadvertent discharges of radionuclides expected not to be in the plants inventory. It is demonstrated that, as for operation of nuclear power plants, the limits prescribed in the Ordinance on Radiological Protection can be met using existing air cleaning technology, Optimization of protection results in public exposures substantially below the limits. In the frame of the regulatory investigation programme a study has been conducted to assess the airborne radioactivity created during certain decommissioning activities like decontamination, segmentation and handling of contaminated or activated parts. The essential results of this study are presented, which are supposed to support planning for decommissioning, for LWRs, Co-60 and Cs-137 are expected to be the dominant radionuclides in airborne discharges. 18 refs., 2 figs., 1 tab.

  4. Observation of fluxes of electrons scattered by the atmosphere in the second Araks experiment

    International Nuclear Information System (INIS)

    Lyachov, S.B.; Managadze, G.G.

    1980-01-01

    This paper describes the results of the USHBA spectrometer measurements of the fluxes of atmospheric scattered electrons in the second Araks experiment. The experimental data are presented for heights from 100 to 140 km. The spectral distributions of the scattered electron fluxes are given and the altitude variation of their intensity is compared with the atmosphere models. The conclusion is made about the possible effect of rocket gassing on the electron scattering processes for definite angles of injection

  5. Presentation and interpretation of field experiments of gaseous UF6 releases in the atmosphere

    International Nuclear Information System (INIS)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G.

    1992-01-01

    An experimental programme concerning the behaviour of UF 6 released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the french Atomic Energy Commission and Eurodif. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get informations about the kinetics of the hydrolysis reaction of the UF 6 , the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles

  6. Presentation and interpretation of field experiments of gaseous UF6 releases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Dept. de Protection de l`Environnement et des Installations; Geisse, C.; Iacona, L. [EURODIF, 26 - Pierrelatte (France)

    1992-12-31

    An experimental programme concerning the behaviour of UF{sub 6} released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the french Atomic Energy Commission and Eurodif. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get informations about the kinetics of the hydrolysis reaction of the UF{sub 6}, the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles.

  7. Characterizing Mobile/Less-Mobile Porosity and Solute Exchange in Dual-Domain Media Using Tracer Experiments and Electrical Measurements in a Hassler-Type Core Holder

    Science.gov (United States)

    Falzone, S.; Slater, L. D.; Day-Lewis, F. D.; Parker, B. L.; Keating, K.; Robinson, J.

    2017-12-01

    Mass transfer is the process by which solute is retained in less-mobile porosity domains, and later released into the mobile porosity domain. This process is often responsible for the slow arrival and gradual release of contaminants and solute tracers. Recent studies have outlined methods using dual-domain mass transfer (DDMT) models for characterizing this phenomenon. These models use the non-linear relationship of bulk (σb) and fluid (σf) conductivity, collected from electrical methods during tracer experiments, to characterize the less-mobile/mobile porosity ratio (β) and the mass-transfer rate coefficient (α). DDMT models use the hysteretic σb-σf relationship observed while solute tracers are injected and then flushed from a sample media. Due to limitations in observing the hysteretic σb-σf relationship, this method has not been used to characterize low permeability samples. We have developed an experimental method for testing porous rock cores that allows us to develop a fundamental understanding of contaminant storage and release in consolidated rock. We test the approach on cores from sedimentary rock sites where mass transfer is expected to occur between hydraulically connected fractures and the adjacent low permeability rock matrix. Our method uses a Hassler-type core holder, designed to apply confining pressure around the outside of a sample core, which hydraulically isolates the sample core, allowing water to be injected into it at increased pressures. The experimental apparatus was also designed to measure σb with spectral induced polarization (SIP) measurements, and σf from a sampling port located at the center of the core. Cores were initially saturated with a solution with high electrical conductivity ( 80000 μS/cm). DI water was then injected into the cores at elevated pressures (>60 psi) and the saturating solution was flushed from the cores, in order to generate flow rates fast enough to capture the non-linear σb-σf relationship

  8. ACS experiment for atmospheric studies on "ExoMars-2016" Orbiter

    Science.gov (United States)

    Korablev, O. I.; Montmessin, F.; Fedorova, A. A.; Ignatiev, N. I.; Shakun, A. V.; Trokhimovskiy, A. V.; Grigoriev, A. V.; Anufreichik, K. A.; Kozlova, T. O.

    2015-12-01

    ACS is a set of spectrometers for atmospheric studies (Atmospheric Chemistry Suite). It is one of the Russian instruments for the Trace Gas Orbiter (TGO) of the Russian-European "ExoMars" program. The purpose of the experiment is to study the Martian atmosphere by means of two observations regimes: sensitive trace gases measurements in solar occultations and by monitoring the atmospheric state during nadir observations. The experiment will allow us to approach global problems of Mars research such as current volcanism, and the modern climate status and its evolution. Also, the experiment is intended to solve the mystery of methane presence in the Martian atmosphere. Spectrometers of the ACS set cover the spectral range from the near IR-range (0.7 μm) to the thermal IR-range (17 μm) with spectral resolution λ/Δλ reaching 50000. The ACS instrument consists of three independent IR spectrometers and an electronics module, all integrated in a single unit with common mechanical, electrical and thermal interfaces. The article gives an overview of scientific tasks and presents the concept of the experiment.

  9. The Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) Experiment Overview: Binational Dye Tracer Releases to Study Pollution Transport and Dilution.

    Science.gov (United States)

    Feddersen, F.; Giddings, S. N.; Kumar, N.; Grimes, D. J.; Pawlak, G. R.; Rivas, D.; Diaz, M.

    2016-02-01

    Per square km, the surfzone and inner-shelf are by far the most economically and ecologically important ocean regions, vital for recreation, food, and ecosystem services. Despite the importance of clean coastal waters to our economy and well-being, declining water quality threatens coastal ecosystem and human health worldwide. Healthy coasts are a significant priority to federal agencies, local government, and NGOs. In particular the San Diego US and Tijuana Mexico border region have unique and persistent water quality issues due to a range of pollution sources. Cross-shore exchange of tracers (e.g., pathogens, anthropogenic nutrients, harmful algal blooms - HABs, larvae) between the well-mixed surfzone and stratified inner-shelf is poorly understood. The surfzone, inner- and mid-shelf span drastically different dynamical regimes, with varying cross-shelf exchange mechanisms due to wave, wind, buoyancy, and tidal processes and intrinsic variability. The NSF funded CSIDE (Cross Surfzone/Inner-shelf Dye Exchange) experiment (Sept & Oct 2015) aims to increase our understanding of cross-shelf material exchange by performing 3 shoreline dye release experiments that are tracked for up to 20 km alongshore and over 48+ hrs. One dye release will be performed in Mexico and the dye transport tracked across the border. The dye will be tracked via a broad range of binational instrumentation. In this presentation, we present an overview of the CSIDE experiment, in particular the binational aspects of the study,

  10. Mass size distribution of particles emitted by diesel engines and determination of the contribution of diesel particles to the atmospheric aerosol in Vienna by using a tracer suitable for activation analysis

    International Nuclear Information System (INIS)

    Norek, C.

    1985-01-01

    In Vienna a large fraction of light absorbing aerosols has been found. The traffic could be a source for the high absorption coefficients, since the time dependent absorption coefficients varise similar to the traffic densities. Diesel vehicles have high soot emissions, so they may contribute considerably to light absorption during the summer. The emission factors of the vehicles were estimated by measurements at different motor and driving conditions by the Constant-Volume-Sampling-Method. To determine the size distributions a 10-stage-low pressure impactor with a lower cut size of 0.015 μm aerodynamic particle diameter was used. In order to estimate the contribution of diesel vehicles to the total mass concentrations all diesel fuel sold in Vienna and its vincinity was marked with an organic Dysprosium compound. This rare earth tracer was emitted by vehicles together with the soot particles and collected at eleven stations in Vienna. The filter samples were extracted with diluted HNO 3 and the extraction was analysed for Dy by neutron activation analysis. The mass size distributions of the particles and the soot emitted from diesel engines are only slightly influenced by motor and driving parameters. The total mass emissions showed considerable variations, but the mean emission factor obtained from the tests was 2.43 g per litre fuel; knowing also the concentration of the tracer in the fuel, the contribution of diesel particles to the mass of the suspended particulates could be estimated. During the measuring period the contribution was c. 25% to the total mass and c. 40% to the absorbing matter in the atmosphere. (Author)

  11. 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.

  12. Selection of tracers for oil and gas evaluation

    International Nuclear Information System (INIS)

    Bjoernstad, T.

    1991-08-01

    The importance of tracer tests in reservoir descriptions is increasingly acknowledged by reservoir engineers as a method to obtain valuable dynamic information from the reservoir. The report describes the ''state-of-the art'' on tracer technology for interwell investigations. Experiences gained from a number of reported field tracer tests are reviewed, and results from detailed laboratory investigations on the static and dynamic behavior of various tracer molecules are discussed. A critical evaluation of the applicability of the various identified tracers is provided. Present and future trends in the development of tracer technology for reservoir description are sketched. 64 refs., 12 figs., 2 tabs

  13. Quadratic tracer dynamical models tobacco growth

    International Nuclear Information System (INIS)

    Qiang Jiyi; Hua Cuncai; Wang Shaohua

    2011-01-01

    In order to study the non-uniformly transferring process of some tracer dosages, we assume that the absorption of some tracer by tobacco is a quadratic function of the tracer quantity of the tracer in the case of fast absorption, whereas the exclusion of the tracer from tobacco is a linear function of the tracer quantity in the case of slow exclusion, after the tracer is introduced into tobacco once at zero time. A single-compartment quadratic dynamical model of Logistic type is established for the leaves of tobacco. Then, a two-compartment quadratic dynamical model is established for leaves and calms of the tobacco. Qualitative analysis of the models shows that the tracer applied to the leaves of the tobacco is excluded finally; however, the tracer stays at the tobacco for finite time. Two methods are also given for computing the parameters in the models. Finally, the results of the models are verified by the 32 P experiment for the absorption of tobacco. (authors)

  14. Arsenic species in atmospheric particulate matter as tracer of the air quality of Doñana Natural Park (SW Spain).

    Science.gov (United States)

    González-Castanedo, Y; Sanchez-Rodas, D; Sánchez de la Campa, A M; Pandolfi, M; Alastuey, A; Cachorro, V E; Querol, X; de la Rosa, J D

    2015-01-01

    Sampling and chemical analyses, including major compounds and trace elements, of atmospheric particulate matter (PM10 and PM2.5) have been performed during 2006-2007 in a regional background monitoring station located within the Doñana Natural Park (SW of Spain). This region is strategic for air quality and climate change studies, representing a meeting place of the European and African continents, and the Atlantic Ocean and Mediterranean Sea. The present study based on meteorological parameters demonstrated long-range transport and impact of industrial plumes on the Doñana Natural. Inorganic arsenic species (arsenate and arsenite) have been analyzed in particulate matter (PM) to characterize the impact of near Cu-smelter plumes and demonstrated the long-range transport of industrial pollutants. As(V) is the main specie of As and varies between 95% and 98% of total As in PM10 and 96-97% in PM2.5. The As(V)/As(III) ratio measured in emission plumes of a Cu-smelter are similar to the ratio found in the Doñana Natural Park. The application of Positive Matrix Factorization (PMF) to atmospheric particulate matter estimated the contributions and chemical profiles of natural and anthropogenic sources impacting the Natural Park, demonstrating the industrial origin of the As and other toxic elements in the air. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Distribution of atmospheric mercury in northern Southeast Asia and South China Sea during Dongsha Experiment

    Science.gov (United States)

    Sheu, Guey-Rong; Lin, Neng-Huei; Lee, Chung-Te; Wang, Jia-Lin; Chuang, Ming-Tung; Wang, Sheng-Hsiang; Chi, Kai Hsine; Ou-Yang, Chang-Feng

    2013-10-01

    Northern South China Sea (SCS) is adjacent to major atmospheric mercury (Hg) emission source regions; however, studies concerning regional atmospheric Hg distribution and cycling are very limited. Accordingly, measurements of atmospheric Hg were conducted in March and April during the 2010 Dongsha Experiment to study its spatial and temporal distribution. Atmospheric Hg was measured at Hengchun and Dongsha Island (Taiwan), Da Nang (Vietnam), Chiang Mai (Thailand) and over the northern SCS. Atmospheric Hg concentrations ranged between 1.54 and 6.83 ng m-3, mostly higher than the Northern Hemisphere background value. Regional wind fields and backward trajectories indicated that the atmospheric Hg concentrations over northern SCS should principally reflect the export of the East Asian Hg emissions by northeast monsoon. However, significantly elevated Hg concentrations were always observed at Da Nang, possibly due to the influence of local Hg emissions. Chiang Mai is located in the intense biomass burning region in northern Thailand. Therefore, atmospheric Hg concentrations at Chiang Mai reflected the influence of regional biomass burning Hg emissions. Two dust storms were encountered at Dongsha Island, one on March 16 and the other on March 21, with atmospheric Hg enhancements. Compared with the 2008 summer values, elevated Hg levels were observed at Dongsha Island in the spring of 2010. Summer air masses were mainly from the deep SCS, representing relatively clean marine air. On the other hand, air masses were from the north in spring, passing eastern China or Taiwan prior to reaching Dongsha Island. Results of this research thus demonstrated the transport of atmospheric Hg from the East Asian continent to northern SCS by regional monsoon activity in spring, but special events, such as biomass burning and dust storms, can also cause enhancements of ambient Hg levels.

  16. Space fireworks for upper atmospheric wind measurements by sounding rocket experiments

    Science.gov (United States)

    Yamamoto, M.

    2016-01-01

    Artificial meteor trains generated by chemical releases by using sounding rockets flown in upper atmosphere were successfully observed by multiple sites on ground and from an aircraft. We have started the rocket experiment campaign since 2007 and call it "Space fireworks" as it illuminates resonance scattering light from the released gas under sunlit/moonlit condition. By using this method, we have acquired a new technique to derive upper atmospheric wind profiles in twilight condition as well as in moonlit night and even in daytime. Magnificent artificial meteor train images with the surrounding physics and dynamics in the upper atmosphere where the meteors usually appear will be introduced by using fruitful results by the "Space firework" sounding rocket experiments in this decade.

  17. Transient Atmospheric Circulation Changes in a Grand ensemble of Idealized CO2 Increase Experiments

    Science.gov (United States)

    Karpechko, A.; Manzini, E.; Kornblueh, L.

    2017-12-01

    The yearly evolution with increasing forcing of the large-scale atmospheric circulation is examined in a 68-member ensemble of 1pctCO2 scenario experiments performed with the MPI-ESM model. Each member of the experiment ensemble is integrated for 155 years, from initial conditions taken from a 2000-yr long pre-industrial control climate experiment. The 1pctCO2 scenario experiments are conducted following the protocol of including as external forcing only a CO2 concentration increase at 1%/year, till quadrupling of CO2 concentrations. MPI-ESM is the Max-Planck-Institute Earth System Model (including coupling between the atmosphere, ocean and seaice). By averaging over the 68 members (ensemble mean), atmospheric variability is greatly reduced. Thus, it is possible to investigate the sensitivity to the climate state of the atmospheric response to CO2 doubling. Indicators of global change show the expected monotonic evolution with increasing CO2 and a weak dependence of the thermodynamical response to CO2 doubling on the climate state. The surface climate response of the atmospheric circulation, diagnosed for instance by the pressure at sea level, and the eddy-driven jet response show instead a marked dependence to the climate state, for the Northern winter season. We find that as the CO2 concentration increases above doubling, Northern winter trends in some indicators of atmospheric circulation changes decrease or even reverse, posing the question on what are the causes of this nonlinear behavior. The investigation of the role of stationary waves, the meridional overturning circulation, the decrease in Arctic sea ice and the stratospheric vortex points to the latter as a plausible cause of such nonlinear response.

  18. The Large-Scale Biosphere-Atmosphere Experiment in Amazonia: Analyzing Regional Land Use Change Effects.

    Science.gov (United States)

    Michael Keller; Maria Assunção Silva-Dias; Daniel C. Nepstad; Meinrat O. Andreae

    2004-01-01

    The Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multi-disciplinary, multinational scientific project led by Brazil. LBA researchers seek to understand Amazonia in its global context especially with regard to regional and global climate. Current development activities in Amazonia including deforestation, logging, cattle ranching, and agriculture...

  19. ECOLOGICAL RESEARCH IN THE LARGE-SCALE BIOSPHERE–ATMOSPHERE EXPERIMENT IN AMAZONIA: EARLY RESULTS.

    Science.gov (United States)

    M. Keller; A. Alencar; G. P. Asner; B. Braswell; M. Bustamente; E. Davidson; T. Feldpausch; E. Fern ndes; M. Goulden; P. Kabat; B. Kruijt; F. Luizao; S. Miller; D. Markewitz; A. D. Nobre; C. A. Nobre; N. Priante Filho; H. Rocha; P. Silva Dias; C von Randow; G. L. Vourlitis

    2004-01-01

    The Large-scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, and the prospect for sustainable land use in the Amazon region. Early...

  20. Ecological research in the large-scale biosphere-atmosphere experiment in Amazonia: early results

    NARCIS (Netherlands)

    Keller, M.; Alencar, A.; Asner, G.P.; Braswell, B.; Bustamante, M.; Davidson, E.; Feldpausch, T.; Fernandes, E.; Goulden, M.; Kabat, P.; Kruijt, B.; Luizão, F.; Miller, S.; Markewitz, D.; Nobre, A.D.; Nobre, C.A.; Priante Filho, N.; Rocha, da H.; Silva Dias, P.; Randow, von C.; Vourlitis, G.L.

    2004-01-01

    The Large-scale Biosphere-Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage,. nutrient dynamics, trace gas fluxes,

  1. Stable Atmospheric Boundary Layer Experiment in Spain (SABLES 98) : a report

    NARCIS (Netherlands)

    Cuxart, J.; Yague, C.; Morales, G.; Terradelles, E.; Orbe, J.; Calvo, J.; Vilu-Guerau, de J.; Soler, M.R.; Infante, C.; Buenestado, P.; Espinalt, A.; Jorgensem, H.E.

    2000-01-01

    This paper describes the Stable Atmospheric Boundary Layer Experiment in Spain (SABLES 98), which took place over the northern Spanish plateau comprising relatively flat grassland, in September 1998. The main objectives of the campaign were to study the properties of the mid-latitude stable boundary

  2. The proposed experiment for search of acoustic phenomena from extensive atmospheric showers in Baikal

    International Nuclear Information System (INIS)

    Chernov, Dmitry; Lyashuk, Vladimir; Novikov, Evgeniy

    2009-01-01

    The experiment on registration of acoustic phenomena from Extensive Atmospheric Showers (EAS) falling on Baikal ice is discussed. The hydroacoustic recording will be carried out in response to a radio trigger from installation SPHERE-2 (raised to a height of about 1 km by means of the captive balloon) detecting Cherenkov light from EAS. The new setup of the experiment is necessary to investigate and confirm the obtained indications on acoustic effects from EAS.

  3. Tracer experiments with 15N-labelled wheat to determine the endogenous and exogenous fecal N-proportion

    International Nuclear Information System (INIS)

    Krawielitzki, K.; Timm, E.

    1978-01-01

    In an experiment with growing Wistar rats of 100 g live weight the N-values and the 15 N-frequency of the nitrogen in feces, urine and the experimental carcasses were determined after feeding 15 N-labelled wheat. Proceeding from Czarnetzki's multicompartment model (1969) for N-metabolism in monogastric animals, the measured data were used to calculate the endogenous and exogenous fecal N-proportion of total nitrogen. In agreement with earlier studies the intestinal nitrogen loss was found to rise as the protein intake increased. In this experiment, the intestinal nitrogen loss went up from 8.2 mg N/animal and day (N-free diet) to 33.9 mg N/animal and day at a daily nitrogen intake of 240 mg/animal and day. The true digestibility of the wheat protein (determined by taking into account the rise of fecal N loss) was 97.2% this value being 8.4 units higher than the true digestibility calculated by the conventional regressive method of fecal analysis with a constant value being taken for fecal N loss. In connection with earlier findings, this experiment allows to draw the conclusion that the true digestibility determined conventionally by regression analysis does not reflect the actual digestibility of the protein. (author)

  4. Diffusion from a Ground Level Point Source Experiment with Thermoluminescence Dosimeters and Kr 85 as Tracer Substance

    Energy Technology Data Exchange (ETDEWEB)

    Ruden, B I

    1969-06-15

    In this report the theoretical conditions necessary for the study of the behaviour of released activity by the use of CaSO{sub 4}: Mn thermoluminescence dosimeters are considered. A method is derived for calculating exposure distributions from drifting volume activity. The correlation between exposure distributions and concentration distributions is discussed. One of thirty experiments where Br 82 was released into water through a nozzle some metres above the bottom is described. The resulting exposure distribution was measured in a vertical plane at distances of 10, 50 and 200 metres by CaSO{sub 4}: Mn thermoluminescence dosimeters. The measured exposures are described and discussed. The advantages and disadvantages of the technique are compared with other methods. The method using exposure measurements for the study of active release in water has given satisfactory results in practice. The measurements have been made at concentration levels which are considerably below that permissible for drinking water according to the recommendations by ICRPA special advantage with this method is that the measurements can be made simultaneously at a large number of places and that integration is possible over sufficiently long periods of time. An experiment is described where Ar 41 was released in free air at a height of one metre above ground and the resulting exposure distribution was measured in a vertical plane at 100 and 250 metres distance by CaSO{sub 4}: Mn thermoluminescence dosimeters. Shielding problems in connection with the experiments have been small since the method permits the measurement of very small doses. An account is given of the possibility of using the beta emitting isotope Kr 85 instead of the gamma emitting Ar 41 for diffusion experiments in air. The results obtained from some experiments are presented and discussed. The thermoluminescent signal from the dosimeters are, at the same concentration and exposure time, 2.5 times greater for Kr 85 than for

  5. Modelling of atmospheric mid-infrared radiative transfer: the AMIL2DA algorithm intercomparison experiment

    International Nuclear Information System (INIS)

    Clarmann, T. von; Hoepfner, M.; Funke, B.; Lopez-Puertas, M.; Dudhia, A.; Jay, V.; Schreier, F.; Ridolfi, M.; Ceccherini, S.; Kerridge, B.J.; Reburn, J.; Siddans, R.

    2003-01-01

    When retrieving atmospheric parameters from radiance spectra, the forward modelling of radiative transfer through the Earth's atmosphere plays a key role, since inappropriate modelling directly maps on to the retrieved state parameters. In the context of pre-launch activities of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) experiment, which is a high resolution limb emission sounder for measurement of atmospheric composition and temperature, five scientific groups intercompared their forward models within the framework of the Advanced MIPAS Level 2 Data Analysis (AMIL2DA) project. These forward models have been developed, or, in certain respects, adapted in order to be used as part of the groups' MIPAS data processing. The following functionalities have been assessed: the calculation of line strengths including non-local thermodynamic equilibrium, the evaluation of the spectral line shape, application of chi-factors and semi-empirical continua, the interpolation of pre-tabulated absorption cross sections in pressure and temperature, line coupling, atmospheric ray tracing, the integration of the radiative transfer equation through an inhomogeneous atmosphere, the convolution of monochromatic spectra with an instrument line shape function, and the integration of the incoming radiances over the instrument field of view

  6. Atlas of the global distribution of atmospheric heating during the global weather experiment

    Science.gov (United States)

    Schaack, Todd K.; Johnson, Donald R.

    1991-01-01

    Global distributions of atmospheric heating for the annual cycle of the Global Weather Experiment are estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) Level 3b data set. Distributions of monthly, seasonally, and annually averaged heating are presented for isentropic and isobaric layers within the troposphere and for the troposphere as a whole. The distributions depict a large-scale structure of atmospheric heating that appears spatially and temporally consistent with known features of the global circulation and the seasonal evolution.

  7. Presentation and interpretation of field experiments of gaseous UF{sub 6} releases in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Crabol, B.; Boulaud, D.; Deville-Cavelin, G. [CEA/Inst. de Protection et de Surete Nucleaire, Dept. de Protection de l' Environnement et des Installations, Fontenay-aux-Roses (France); Geisse, C.; Iacona, L. [EURODIF/Production, Site de Tricastin, Pierrelatte Cedex (France)

    1992-07-01

    An experimental programme concerning the behaviour of UF{sub 6} released in gaseous phase in the atmosphere has been conducted in the years 1986-1989 by the French Atomic Energy Commission and EURODIF. Three field tests have been performed on the CEA/CESTA experimental site. These experiments permitted to get information about the kinetics of the hydrolysis reaction of the UF{sub 6}, the behaviour of the hydrolysis products in the atmosphere and the granulometry of the solid particles. (author)

  8. Benchmarking numerical codes for tracer transport with the aid of laboratory-scale experiments in 2D heterogeneous porous media.

    Science.gov (United States)

    Maina, Fadji Hassane; Ackerer, Philippe; Younes, Anis; Guadagnini, Alberto; Berkowitz, Brian

    2017-06-07

    We present a combined experimental and numerical modeling study that addresses two principal questions: (i) is any particular Eulerian-based method used to solve the classical advection-dispersion equation (ADE) clearly superior (relative to the others), in terms of yielding solutions that reproduce BTCs of the kind that are typically sampled at the outlet of a laboratory cell? and (ii) in the presence of matches of comparable quality against such BTCs, do any of these methods render different (or similar) numerical BTCs at locations within the domain? To address these questions, we obtained measurements from carefully controlled laboratory experiments, and employ them as a reference against which numerical results are benchmarked and compared. The experiments measure solute transport breakthrough curves (BTCs) through a square domain containing various configurations of coarse, medium, and fine quartz sand. The approaches to solve the ADE involve Eulerian-Lagrangian and Eulerian (finite volume, finite elements, mixed and discontinuous finite elements) numerical methods. Model calibration is not examined; permeability and porosity of each sand were determined previously through separate, standard laboratory tests, while dispersivities are assigned values proportional to mean grain size. We find that the spatial discretization of the flow field is of critical importance, due to the non-uniformity of the domain. Although simulated BTCs at the system outlet are observed to be very similar for these various numerical methods, computed local (point-wise, inside the domain) BTCs can be very different. We find that none of the numerical methods is able to fully reproduce the measured BTCs. The impact of model parameter uncertainty on the calculated BTCs is characterized through a set of numerical Monte Carlo simulations; in cases where the impact is significant, assessment of simulation matches to the experimental data can be ambiguous. Copyright © 2017 Elsevier B.V. All

  9. Numerical experiments on the atmospheric response to cold Equatorial Pacific conditions ('La Nina') during northern summer

    International Nuclear Information System (INIS)

    Storch, H. von; Schriever, D.; Arpe, K.; Branstator, G.W.; Legnani, R.; Ulbrich, U.

    1993-01-01

    The effect of cold conditions in the central and eastern Equatorial Pacific during Northern Summer is examined in a series of numerical experiments with the low resolution (T21) atmospheric general circulation model ECHAM2. Anomalous sea surface temperatures (SST) as observed in June 1988 were prescribed and the effect on the global circulation is examined. In the model atmosphere, the anomalous cold water in the Equatorial Pacific excites a strong and stable response over the tropical Central and East Pacific. From here stationary Rossby waves radiate into both hemispheres. The Northern Hemisphere wave train is weak and affects only the Northeast Pacific area; the Southern Hemisphere wave train arches from the Central Pacific over the southern tip of South America to the South Atlantic. This response is not only present in the basic anomaly experiment with the T21 GCM but also in experiments with SST anomalies confined to the tropics and with an envelope-formulation of the SST anomalies, in experiments with a linear model, and in high resolution (T42) model experiments. The model output is also compared to the actually observed atmospheric state in June 1988. (orig./KW)

  10. Hanford 67-series: a volume of atmospheric field diffusion measurements

    International Nuclear Information System (INIS)

    Nickola, P.W.

    1977-11-01

    This volume documents atmospheric diffusion experiments carried out at the Hanford reservation during the period 1967 to 1973. A total of 103 tracer releases during 54 release periods is tabulated. Multi-tracer releases (generally from different elevations) were made during most of the experimental periods. Release heights varied from ground level to an elevation of 111 m. Tracers were sampled simultaneously on as many as 10 arcs at distances of up to 12.8 km from the tracer release point. As many as 718 field sampling locations were employed during some of the experiments. Vertical profiles of concentration were monitored on towers during 23 of the 54 release periods. Concurrent vertical profiles of mean temperature, of mean wind speed and direction, and of direction standard deviation are also tabled for elevations up to 122 m

  11. An experiment for Shuttle aerodynamic force coefficient determination from inflight dynamical and atmospheric measurements

    Science.gov (United States)

    Compton, H. R.; Blanchard, R. C.; Walberg, G. D.

    1978-01-01

    A two-phase experiment is proposed which utilizes the Shuttle Orbiter and its unique series of repeated entries into the earth's atmosphere as an airborne in situ aerodynamic testing laboratory. The objective of the experiment is to determine static aerodynamic force coefficients, first of the orbiter, and later of various entry configurations throughout the high speed flight regime, including the transition from free molecule to continuum fluid flow. The objective will be accomplished through analysis of inflight measurements from both shuttle-borne and shuttle-launched instrumented packages. Results are presented to demonstrate the feasibility of such an experiment.

  12. Tracer filamentation at an unstable ocean front

    Science.gov (United States)

    Feng, Yen Chia; Mahadevan, Amala; Thiffeault, Jean-Luc; Yecko, Philip

    2017-11-01

    A front, where two bodies of ocean water with different physical properties meet, can become unstable and lead to a flow with high strain rate and vorticity. Phytoplankton and other oceanic tracers are stirred into filaments by such flow fields, as can often be seen in satellite imagery. The stretching and folding of a tracer by a two-dimensional flow field has been well studied. In the ocean, however, the vertical shear of horizontal velocity is typically two orders of magnitude larger than the horizontal velocity gradient. Theoretical calculations show that vertical shear alters the way in which horizontal strain affects the tracer, resulting in thin, sloping structures in the tracer field. Using a non-hydrostatic ocean model of an unstable ocean front, we simulate tracer filamentation to identify the effect of vertical shear on the deformation of the tracer. In a complementary laboratory experiment, we generate a simple, vertically sheared strain flow and use dye and particle image velocimetry to quantify the filamentary structures in terms of the strain and shear. We identify how vertical shear alters the tracer filaments and infer how the evolution of tracers in the ocean will differ from the idealized two-dimensional paradigm. Support of NSF DMS-1418956 is acknowledged.

  13. Space, place and atmosphere. Emotion and peripherical perception in architectural experience

    Directory of Open Access Journals (Sweden)

    Juhani Pallasmaa

    2014-07-01

    Full Text Available Architectural experiences are essentially multi-sensory and simultaneous, and a complex entity is usually grasped as an atmosphere, ambience or feeling. In fact, the judgement concerning the character of a space or place calls for categories of sensing that extend beyond the five Aristotelian senses, such as the embodied existential sense, and, as a result, the entity is perceived in a diffuse, peripheral and unconscious manner. Paradoxically, we grasp an atmosphere before we have consciously identified its constituent factors and ingredients. «We perceive atmospheres through our emotional sensibility – a form of perception that works incredibly quickly, and which we humans evidently need to help us survive», Peter Zumthor suggests. We are mentally and emotionally affected by works of art before we understand them, or we may not understand them intellectually at all. Sensitive artists and architects intuit experiential and emotive qualities of spaces, places and images. This capacity calls for a specific kind of imagination, an emphatic imagination. Atmospheres are percieved peripherally through diffuse vision interacting with other sense modalities, and they are experienced emotionally rather than intellectually. The studies on the differentiation of the two brain hemispheres suggest that atmospheres are perceived through the right hemisphere. Somewhat surprisingly, atmospheres are more conscious objectives in literature, cinema, theater, painting and music than in architecture, which has been traditionally approached formally and perceived primarily through focused vision. Yet, when we see a thing in focus, we are outsiders to it, whereas the experience of being in a space calls for peripheral and unfocused perception. One of the reasons for the experiential poverty of contemporary settings could be in the poverty of their peripheral stimuli.

  14. Atmospheric boundary layer response to sea surface temperatures during the SEMAPHORE experiment

    Science.gov (United States)

    Giordani, Hervé; Planton, Serge; Benech, Bruno; Kwon, Byung-Hyuk

    1998-10-01

    The sensitivity of the marine atmospheric boundary layer (MABL) subjected to sea surface temperatures (SST) during the Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment in 1993 has been studied. Atmospheric analyses produced by the Action de Recherche, Petite Echelle, Grande Echelle (ARPEGE) operational model at the French meteorological weather service assimilated data sets collected between October 7 and November 17, 1993, merged with the Global Telecommunication System (GTS) data. Analyses were validated against independent data from aircraft instruments collected along a section crossing the Azores oceanic front, not assimilated into the model. The responses of the mean MABL in the aircraft cross section to changes in SST gradients of about 1°C/100 km were the presence of an atmospheric front with horizontal gradients of 1°C/100 km and an increase of the wind intensity from the cold to the warm side during an anticyclonic synoptic situation. The study of the spatiotemporal characteristics of the MABL shows that during 3 days of an anticyclonic synoptic situation the SST is remarkably stationary because it is principally controlled by the Azores ocean current, which has a timescale of about 10 days. However, the temperature and the wind in the MABL are influenced by the prevailing atmospheric conditions. The ocean does not appear to react to the surface atmospheric forcing on the timescale of 3 days, whereas the atmospheric structures are modified by local and synoptic-scale advection. The MABL response appears to be much quicker than that of the SSTs. The correlation between the wind and the thermal structure in the MABL is dominated by the ageostrophic and not by the geostrophic component. In particular, the enhancement of the wind on either side of the SST front is mainly due to the ageostrophic component. Although the surface heat fluxes are not the only cause of ageostrophy, the

  15. Packet Tracer network simulator

    CERN Document Server

    Jesin, A

    2014-01-01

    A practical, fast-paced guide that gives you all the information you need to successfully create networks and simulate them using Packet Tracer.Packet Tracer Network Simulator is aimed at students, instructors, and network administrators who wish to use this simulator to learn how to perform networking instead of investing in expensive, specialized hardware. This book assumes that you have a good amount of Cisco networking knowledge, and it will focus more on Packet Tracer rather than networking.

  16. Simulation of a field scale tritium tracer experiment in a fractured, weathered shale using discrete-fracture/matrix-diffusion and equivalent porous medium models

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, Paige L. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Geological Sciences

    1996-05-01

    Simulations of a tritium tracer experiment in fractured shale saprolite, conducted at the Oak Ridge National Laboratory, were performed using 1D and 2D equivalent porous medium (EPM) and discrete-fracture/matrix-diffusion (DFMD) models. The models successfully reproduced the general shape of the breakthrough curves in down-gradient monitoring wells which are characterized by rapid first arrival, a slow-moving center of mass, and a persistent ``tail`` of low concentration. In plan view, the plume shows a large degree of transverse spreading with the width almost as great as the length. EPM models were sensitive to dispersivity coefficient values which had to be large (relative to the 3.7m distance between the injection and monitoring wells) to fit the tail and transverse spreading. For example, to fit the tail a longitudinal dispersivity coefficient, αL, of 0.8 meters for the 2D simulations was used. To fit the transverse spreading, a transverse dispersivity coefficient, αT, of 0.8 to 0.08 meters was used indicating an αLT ratio between 10 and 1. Transverse spreading trends were also simulated using a 2D DFMD model using a few larger aperture fractures superimposed onto an EPM. Of the fracture networks studied, only those with truncated fractures caused transverse spreading. Simulated tritium levels in all of the cases were larger than observed values by a factor of approximately 100. Although this is partly due to input of too much tritium mass by the models it appears that dilution in the wells, which were not purged prior to sampling, is also a significant factor. The 1D and 2D EPM models were fitted to monitoring data from the first five years of the experiment and then used to predict future tritium concentrations.

  17. Simulation of a field scale tritium tracer experiment in a fractured, weathered shale using discrete-fracture/matrix-diffusion and equivalent porous medium models

    International Nuclear Information System (INIS)

    Stafford, P.L.

    1996-05-01

    Simulations of a tritium tracer experiment in fractured shale saprolite, conducted at the Oak Ridge National Laboratory, were performed using 1D and 2D equivalent porous medium (EPM) and discrete-fracture/matrix-diffusion (DFMD) models. The models successfully reproduced the general shape of the breakthrough curves in down-gradient monitoring wells which are characterized by rapid first arrival, a slow-moving center of mass, and a persistent ''tail'' of low concentration. In plan view, the plume shows a large degree of transverse spreading with the width almost as great as the length. EPM models were sensitive to dispersivity coefficient values which had to be large (relative to the 3.7m distance between the injection and monitoring wells) to fit the tail and transverse spreading. For example, to fit the tail a longitudinal dispersivity coefficient, α L , of 0.8 meters for the 2D simulations was used. To fit the transverse spreading, a transverse dispersivity coefficient, α T , of 0.8 to 0.08 meters was used indicating an α L /α T ratio between 10 and 1. Transverse spreading trends were also simulated using a 2D DFMD model using a few larger aperture fractures superimposed onto an EPM. Of the fracture networks studied, only those with truncated fractures caused transverse spreading. Simulated tritium levels in all of the cases were larger than observed values by a factor of approximately 100. Although this is partly due to input of too much tritium mass by the models it appears that dilution in the wells, which were not purged prior to sampling, is also a significant factor. The 1D and 2D EPM models were fitted to monitoring data from the first five years of the experiment and then used to predict future tritium concentrations

  18. Composition of the earth's atmosphere by shock-layer radiometry during the PAET entry probe experiment.

    Science.gov (United States)

    Whiting, E. E.; Arnold, J. O.; Page, W. A.; Reynolds, R. M.

    1973-01-01

    A determination of the composition of the earth's atmosphere obtained from onboard radiometer measurements of the spectra emitted from the bow shock layer of a high-speed entry probe is reported. The N2, O2, CO2, and noble gas concentrations in the earth's atmosphere were determined to good accuracy by this technique. The results demonstrate unequivocally the feasibility of determining the composition of an unknown planetary atmosphere by means of a multichannel radiometer viewing optical emission from the heated atmospheric gases in the region between the bow shock wave and the vehicle surface. The spectral locations in this experiment were preselected to enable the observation of CN violet, N2(+) first negative and atomic oxygen emission at 3870, 3910, and 7775 A, respectively. The atmospheric gases were heated and compressed by the shock wave to a peak temperature of about 6100 K and a corresponding pressure of 0.4 atm. Complete descriptions of the data analysis technique and the onboard radiometer and its calibration are given.

  19. Definition of Atmospheric Science Experiments and Techniques: Wake Zone Mapping Experiments

    Science.gov (United States)

    Taeusch, D. R.

    1976-01-01

    The development of a subsatellite system has been proposed for the shuttle program which would provide to the scientific community a platform for experiments which would be tethered to the shuttle spacecraft orbiting at about 200 km altitude. Experiments which can perform measurements of aeronomic interest onboard or utilizing the tethered satellite concept are described and recommended.

  20. Multi-Scale Thermal Heat Tracer Tests for Characterizing Transport Processes and Flow Channelling in Fractured Media: Theory and Field Experiments

    Science.gov (United States)

    de La Bernardie, J.; Klepikova, M.; Bour, O.; Le Borgne, T.; Dentz, M.; Guihéneuf, N.; Gerard, M. F.; Lavenant, N.

    2017-12-01

    The characterization of flow and transport in fractured media is particularly challenging because hydraulic conductivity and transport properties are often strongly dependent on the geometric structure of the fracture surfaces. Here we show how thermal tracer tests may be an excellent complement to conservative solute tracer tests to infer fracture geometry and flow channeling. We performed a series of thermal tracer tests at different scales in a crystalline rock aquifer at the experimental site of Ploemeur (H+ observatory network). The first type of thermal tracer tests are push-pull tracer tests at different scales. The temporal and spatial scaling of heat recovery, measured from thermal breakthrough curves, shows a clear signature of flow channeling. In particular, the late time tailing of heat recovery under channeled flow is shown to diverge from the T(t) α t-1,5 behavior expected for the classical parallel plate model and follow the scaling T(t) α 1/t(logt)2 for a simple channel modeled as a tube. Flow channeling is also manifested on the spatial scaling of heat recovery as flow channeling affects the decay of the thermal breakthrough peak amplitude and the increase of the peak time with scale. The second type of thermal tracer tests are flow-through tracer tests where a pulse of hot water was injected in a fracture isolated by a double straddle packer while pumping at the same flow rate in another fracture at a distance of about 10 meters to create a dipole flow field. Comparison with a solute tracer test performed under the same conditions also present a clear signature of flow channeling. We derive analytical expressions for the retardation and decay of the thermal breakthrough peak amplitude for different fracture geometries and show that the observed differences between thermal and solute breakthrough can be explained only by channelized flow. These results suggest that heat transport is much more sensitive to fracture heterogeneity and flow

  1. Lunar atmospheric composition experiment. Final report, 1 Jun. 1971 - 30 Sep. 1975

    International Nuclear Information System (INIS)

    Hoffman, J.H.

    1975-01-01

    Apollo 17 carried a miniature mass spectrometer, called the Lunar Atmospheric Composition Experiment (LACE), to the moon as part of the Apollo Lunar Surface Experiments Package (ALSEP) to study the composition and variations in the lunar atmosphere. The instrument was successfully deployed in the Taurus-Littrow Valley with its entrance aperture oriented upward to intercept and measure the downward flux of gases at the lunar surface. During the ten lunations that the LACE operated, it produced a large base of data on the lunar atmosphere, mainly collected at night time. It was found that thermal escape is the most rapid loss mechanism for hydrogen and helium. For heavier gases, photoionization followed by acceleration through the solar wind electric field accounted for most of the loss. The dominant gases on the moon were argon and helium, and models formed for their distribution are described in detail. It is concluded that most of the helium in the lunar atmosphere is of solar wind origin, and that there also exist very small amounts of methane, ammonia, and carbon dioxide

  2. Validation of the BERT Point Source Inversion Scheme Using the Joint Urban 2003 Tracer Experiment Dataset - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Sara [Los Alamos National Laboratory; Brown, Michael J. [Los Alamos National Laboratory

    2012-06-18

    zones. Due to a unique source inversion technique - called the upwind collector footprint approach - the tool runs fast and the source regions can be determined in a few minutes. In this report, we provide an overview of the BERT framework, followed by a description of the source inversion technique. The Joint URBAN 2003 field experiment held in Oklahoma City that was used to validate BERT is then described. Subsequent sections describe the metrics used for evaluation, the comparison of the experimental data and BERT output, and under what conditions the BERT tool succeeds and performs poorly. Results are aggregated in different ways (e.g., daytime vs. nighttime releases, 1 vs. 2 vs. 3 hit collectors) to determine if BERT shows any systematic errors. Finally, recommendations are given for how to improve the code and procedures for optimizing performance in operational mode.

  3. Atmospheric-like rotating annulus experiment: gravity wave emission from baroclinic jets

    Science.gov (United States)

    Rodda, Costanza; Borcia, Ion; Harlander, Uwe

    2017-04-01

    Large-scale balanced flows can spontaneously radiate meso-scale inertia-gravity waves (IGWs) and are thus in fact unbalanced. While flow-dependent parameterizations for the radiation of IGWs from orographic and convective sources do exist, the situation is less developed for spontaneously emitted IGWs. Observations identify increased IGW activity in the vicinity of jet exit regions. A direct interpretation of those based on geostrophic adjustment might be tempting. However, directly applying this concept to the parameterization of spontaneous imbalance is difficult since the dynamics itself is continuously re-establishing an unbalanced flow which then sheds imbalances by GW radiation. Examining spontaneous IGW emission in the atmosphere and validating parameterization schemes confronts the scientist with particular challenges. Due to its extreme complexity, GW emission will always be embedded in the interaction of a multitude of interdependent processes, many of which are hardly detectable from analysis or campaign data. The benefits of repeated and more detailed measurements, while representing the only source of information about the real atmosphere, are limited by the non-repeatability of an atmospheric situation. The same event never occurs twice. This argues for complementary laboratory experiments, which can provide a more focused dialogue between experiment and theory. Indeed, life cycles are also examined in rotating- annulus laboratory experiments. Thus, these experiments might form a useful empirical benchmark for theoretical and modelling work that is also independent of any sort of subgrid model. In addition, the more direct correspondence between experimental and model data and the data reproducibility makes lab experiments a powerful testbed for parameterizations. Joint laboratory experiment and numerical simulation have been conducted. The comparison between the data obtained from the experiment and the numerical simulations shows a very good

  4. Exploring Hydrofluorocarbons as Groundwater Age Tracers (Invited)

    Science.gov (United States)

    Haase, K. B.; Busenberg, E.; Plummer, L. N.; Casile, G.; Sanford, W. E.

    2013-12-01

    Groundwater dating tracers are an essential tool for analyzing hydrologic conditions in groundwater systems. Commonly used tracers for dating post-1940's groundwater include sulfur hexafluoride (SF6), chlorofluorocarbons (CFCs), 3H-3He, and other isotopic tracers (85Kr, δ2H and δ18O isotopes, etc.). Each tracer carries a corresponding set of advantages and limitations imposed by field, analytical, and interpretive methods. Increasing the number available tracers is appealing, particularly if they possess inert chemical properties and unique temporal emission histories from other tracers. Atmospherically derived halogenated trace gases continue to hold untapped potential for new tracers, as they are generally inert and their emission histories are well documented. SF5CF3, and CFC-13 were previously shown to have application as dating tracers, though their low mixing ratios and low solubility require large amounts of water to be degassed for their quantification. Two related groups of compounds, hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) are hypothesized to be potential age tracers, having similar mixing ratios to the CFCs and relatively high solubility. However, these compounds yield gas chromatography electron capture detector (GC-ECD) responses that are 10-2 -10-5 less than CFC-12, making purge and trap or field stripping GC-ECD approaches impractical. Therefore, in order to use dissolved HCFCs and HFCs as age tracers, different approaches are needed. To solve this problem, we developed an analytical method that uses an atomic emission detector (GC-AED) in place of an ECD to detect fluorinated compounds. In contrast to the ECD, the AED is a universally sensitive, highly linear, elementally specific detector. The new GC-AED system is being used to measure chlorodifluoromethane (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a), and other fluorinated compounds in one liter water samples to study their potential as age dating tracers. HCFC-22 is a

  5. IKONOS imagery for the Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA).

    Science.gov (United States)

    George Hurtt; Xiangming Xiao; Michael Keller; Michael Palace; Gregory P. Asner; Rob Braswell; Brond& #305; Eduardo S. zio; Manoel Cardoso; Claudio J.R. Carvalho; Matthew G. Fearon; Liane Guild; Steve Hagen; Scott Hetrick; Berrien Moore III; Carlos Nobre; Jane M. Read; S& aacute; Tatiana NO-VALUE; Annette Schloss; George Vourlitis; Albertus J. Wickel

    2003-01-01

    The LBA-ECO program is one of several international research components under the Brazilian-led Large Scale Biosphere–Atmosphere Experiment in Amazonia (LBA). The field-oriented research activities of this study are organized along transects and include a set of primary field sites, where the major objective is to study land-use change and ecosystem dynamics, and a...

  6. The effect of high-resolution orography on numerical modelling of atmospheric flow: a preliminary experiment

    International Nuclear Information System (INIS)

    Scarani, C.; Tampieri, F.; Tibaldi, S.

    1983-01-01

    The effect of increasing the resolution of the topography in models of numerical weather prediction is assessed. Different numerical experiments have been performed, referring to a case of cyclogenesis in the lee of the Alps. From the comparison, it appears that the lower atmospheric levels are better described by the model with higherresolution topography; comparable horizontal resolution runs with smoother topography appear to be less satisfactory in this respect. It turns out also that the vertical propagation of the signal due to the front-mountain interaction is faster in the high-resolution experiment

  7. Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus clay, anhydrite and quartz

    Science.gov (United States)

    Zakhnini, Abdelhamid; Kulenkampff, Johannes; Sauerzapf, Sophie; Pietrzyk, Uwe; Lippmann-Pipke, Johanna

    2013-08-01

    Understanding conservative fluid flow and reactive tracer transport in soils and rock formations requires quantitative transport visualization methods in 3D+t. After a decade of research and development we established the GeoPET as a non-destructive method with unrivalled sensitivity and selectivity, with due spatial and temporal resolution by applying Positron Emission Tomography (PET), a nuclear medicine imaging method, to dense rock material. Requirements for reaching the physical limit of image resolution of nearly 1 mm are (a) a high-resolution PET-camera, like our ClearPET scanner (Raytest), and (b) appropriate correction methods for scatter and attenuation of 511 keV—photons in the dense geological material. The latter are by far more significant in dense geological material than in human and small animal body tissue (water). Here we present data from Monte Carlo simulations (MCS) reflecting selected GeoPET experiments. The MCS consider all involved nuclear physical processes of the measurement with the ClearPET-system and allow us to quantify the sensitivity of the method and the scatter fractions in geological media as function of material (quartz, Opalinus clay and anhydrite compared to water), PET isotope (18F, 58Co and 124I), and geometric system parameters. The synthetic data sets obtained by MCS are the basis for detailed performance assessment studies allowing for image quality improvements. A scatter correction method is applied exemplarily by subtracting projections of simulated scattered coincidences from experimental data sets prior to image reconstruction with an iterative reconstruction process.

  8. Planetary Radio Interferometry and Doppler Experiment (PRIDE) for Planetary Atmospheric Studies

    Science.gov (United States)

    Bocanegra Bahamon, Tatiana; Cimo, Giuseppe; Duev, Dmitry; Gurvits, Leonid; Molera Calves, Guifre; Pogrebenko, Sergei

    2015-04-01

    The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that allows the determination of the radial velocity and lateral coordinates of planetary spacecraft with very high accuracy (Duev, 2012). The setup of the experiment consists of several ground stations from the European VLBI Network (EVN) located around the globe, which simultaneously perform Doppler tracking of a spacecraft carrier radio signal, and are subsequently processed in a VLBI-style in phase referencing mode. Because of the accurate examination of the changes in phase and amplitude of the radio signal propagating from the spacecraft to the multiple stations on Earth, the PRIDE technique can be used for several fields of planetary research, among which planetary atmospheric studies, gravimetry and ultra-precise celestial mechanics of planetary systems. In the study at hand the application of this technique for planetary atmospheric investigations is demonstrated. As a test case, radio occultation experiments were conducted with PRIDE having as target ESA's Venus Express, during different observing sessions with multiple ground stations in April 2012 and March 2014. Once each of the stations conducts the observation, the raw data is delivered to the correlation center at the Joint Institute for VLBI in Europe (JIVE) located in the Netherlands. The signals are processed with a high spectral resolution and phase detection software package from which Doppler observables of each station are derived. Subsequently the Doppler corrected signals are correlated to derive the VLBI observables. These two sets of observables are used for precise orbit determination. The reconstructed orbit along with the Doppler observables are used as input for the radio occultation processing software, which consists of mainly two modules, the geometrical optics module and the ray tracing inversion module, from which vertical density profiles, and subsequently, temperature and pressure profiles of Venus

  9. An overview of the rangelands atmosphere hydrosphere biosphere interaction study experiment in northeastern Asia (RAISE)

    Science.gov (United States)

    Sugita, Michiaki; Asanuma, Jun; Tsujimura, Maki; Mariko, Shigeru; Lu, Minjiao; Kimura, Fujio; Azzaya, Dolgorsuren; Adyasuren, Tsokhio

    2007-01-01

    SummaryIntensive observations, analysis and modeling within the framework of the rangelands atmosphere-hydrosphere-biosphere interaction study experiment in northeastern Asia (RAISE) project, have allowed investigations into the hydrologic cycle in the ecotone of forest-steppe, and its relation to atmosphere and ecosystem in the eastern part of Mongolia. In this region, changes in the climate have been reported and a market oriented economy was introduced recently, but their impact on the natural environment is still not well understood. In this RAISE special issue, the outcome is presented of the studies carried out by six groups within RAISE, namely: (1) Land-atmosphere interaction analysis, (2) ecosystem analysis and modeling, (3) hydrologic cycle analysis, (4) climatic modeling, (5) hydrologic modeling, and (6) integration. The results are organized in five relevant categories comprising (i) hydrologic cycle including precipitation, groundwater, and surface water, (ii) hydrologic cycle and ecosystem, (iii) surface-atmosphere interaction, (iv) effect of grazing activities on soils, plant ecosystem and surface fluxes, and (v) future prediction. Comparison with studies on rangelands in other parts of the world, and some future directions of studies still needed in this region are also summarized.

  10. Atmospheric Radiation Measurement Madden-Julian Oscillation Investigation Experiment Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Long, Chuck [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.

    2016-07-01

    Every 30–90 days during the Northern Hemisphere winter, the equatorial tropical atmosphere experiences pulses of extraordinarily strong deep convection and rainfall. This phenomenon is referred to as the Madden–Julian Oscillation, or MJO, named after the scientists who identified this cycle. The MJO significantly affects weather and rainfall patterns around the world (Zhang 2013). To improve predictions of the MJO—especially about how it forms and evolves throughout its lifecycle—an international group of scientists collected an unprecedented set of observations from the Indian Ocean and western Pacific region from October 2011 through March 2012 through several coordinated efforts. The coordinated field campaigns captured six distinct MJO cycles in the Indian Ocean. The rich set of observations capturing several MJO events from these efforts will be used for many years to study the physics of the MJO. Here we highlight early research results using data from the Atmospheric Radiation Measurement (ARM) Madden-Julian Oscillation Investigation Experiment (AMIE), sponsored by the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility.

  11. The relationship between sea surface temperature anomalies and atmospheric circulation in general circulation model experiments

    International Nuclear Information System (INIS)

    Kharin, V.V.

    1994-01-01

    Several multi-year integrations of the Hamburg version of the ECMWF/T21 general circulation model driven by the sea surface temperature (SST) observed in the period 1970-1988 were examined to study the extratropical response of the atmospheric circulation to SST anomalies in the Northern Hemisphere in winter. In the first 19-years run SST anomalies were prescribed globally (GAGO run), and in two others SST variability was limited to extratropical regions (MOGA run) and to tropics (TOGA run), respectively. A canonical correlation analysis was applied to the monthly means to find the best correlated patterns of SST anomalies in the Atlantic and Pacific Oceans and the Northern Hemisphere atmospheric flow. Contrary to expectation, the extratropical response in the GAGO run is not equal to the linear combination of the responses in the MOGA and TOGA runs. In the GAGO integration with globally prescribed SST the best correlated atmospheric pattern is global and is characterized by dipole structures of the same polarity in the North Atlantic and the North Pacific sectors. In the MOGA and TOGA experiments the atmospheric response is more local with main centers in the North Atlantic and North Pacific, respectively. The atmospheric modes found by the CCA were compared with the normal modes of the barotropic vorticity equation linearized about the 500 mb winter climate of the control integration driven by the climatological SST. The normal modes with smallest eigenvalues are similar to the canonical patterns of 500 mb geopotential height. The corresponding eigenvectors of the adjoint operator, which represent an external forcing optimal for exciting normal modes, have a longitudinal structure with maxima in regions characterized by enhanced high frequency baroclinic activity over both oceans. It was suggested that variability of storm tracks could play an important role in variability of the barotropic normal modes. (orig.)

  12. Evaluation of local versus remote areas of CH4 sources at IC3 stations using a combined analysis of 222Rn tracer and Atmospheric Particles Transport Model (APTM) results. Application at the Gredos and Iruelas station (GIC3), Spain.

    Science.gov (United States)

    Grossi, Claudia; Morguí, Josep Anton; Curcoll, Roger; Àgueda, Alba; Arnold, Delia; Batet, Oscar; Cañas, Lidia; Nofuentes, Manel; Occhipinti, Paola; Vogel, Felix; Vargas, Arturo; Rodó, Xavier

    2014-05-01

    The Gredos and Iruelas station (GIC3) is part of the IC3 (Institut Català de Ciències del Clima) atmospheric monitoring network. This station is located in the Gredos Natural Park (40.22º N; -5.14º E) in the Spanish central plateau. The IC3 network consists of 8 stations distributed across Spain. It has been developed with the aim of studying climatic processes and the responses of impacted systems at different temporal and spatial scales. Since 2012, CO2, CH4, 222Rn (a natural radioactive gas) and meteorological variables are continuously measured at GIC3 at 20 m a.g.l. (1100 m a.s.l.). Furthermore, 4-days backward simulations are run daily for each IC3 station using the FLEXPART model. Simulations use ECMWF meteorological data as input and a horizontal spatial resolution of 0.2 degrees. The Laboratory of the Atmosphere and the Oceans (LAO) of the IC3 has elaborated a new approach to evaluate the local or remote greenhouse gases emissions using the radon gas as tracer and the atmospheric particles transport model FLEXPART under nocturnal and winter conditions. The ratios between the normalized and rescaled measured concentrations of CH4 and 222Rn during nocturnal hours (21h, 00h, 03h and 06h) and in the winter season, in order to reduce local radon flux and methane source due to seasonal livestock migration and to get stable atmospheric conditions, have been analyzed in relation to the influence of the local area (set to an initial dimension of 20x20 km2). The influence area (IA) has been defined as the percentage of the ratio between the residence time of the fictitious particles released in FLEXPART simulations over the area of interest (TLocal Area) and the residence time of these fictitious particles over the total area included in the simulation (TTotal Area ), i.e. IA = (TLocal Area/TTotal Area * 100). First results considering an area of interest of 20x20 km2 show a linear increase of the radon concentration with IA until reaching a maximum when IA is

  13. A passive heat tracer experiment to determine the seasonal variation in residence times in a managed aquifer recharge system with DTS

    NARCIS (Netherlands)

    des Tombe, B.F.; Bakker, M.; Schaars, F; van der Made, KJ; Calje, R; Borst, L.

    2016-01-01

    Targeted provisional session N°8.01 The seasonal variation in residence times is determined in a managed aquifer recharge system using a passive heat tracer test. The managed aquifer recharge system consists of a sequence of alternating elongated recharge basins and rows of recovery wells. The

  14. Modelling of containment atmosphere mixing and stratification experiment using CFD approach

    International Nuclear Information System (INIS)

    Ivo Kljenak; Miroslav Babic; Borut Mavko; Ivan Bajsic

    2005-01-01

    An experiment on containment atmosphere mixing and stratification, which was originally performed in the TOSQAN facility in Saclay (France), was simulated with the Computational Fluid Dynamics code CFX. The TOSQAN facility consists of a large cylindrical vessel in which gases are injected. In the considered experiment, steam, air and helium were injected during different phases of the experiment, with steam condensing on vessel walls. Three intermediate steady states, which were obtained with different boundary conditions, were simulated independently. A two-dimensional axisymmetric model of the TOSQAN vessel for the CFX4.4 code was developed. The flow in the simulation domain was modelled as single-phase. Steam condensation on vessel walls was modelled as a sink of mass and energy. Calculated profiles of temperature, steam concentration, and velocity components are compared to experimental results. (authors)

  15. Tracer attenuation in groundwater

    Science.gov (United States)

    Cvetkovic, Vladimir

    2011-12-01

    The self-purifying capacity of aquifers strongly depends on the attenuation of waterborne contaminants, i.e., irreversible loss of contaminant mass on a given scale as a result of coupled transport and transformation processes. A general formulation of tracer attenuation in groundwater is presented. Basic sensitivities of attenuation to macrodispersion and retention are illustrated for a few typical retention mechanisms. Tracer recovery is suggested as an experimental proxy for attenuation. Unique experimental data of tracer recovery in crystalline rock compare favorably with the theoretical model that is based on diffusion-controlled retention. Non-Fickian hydrodynamic transport has potentially a large impact on field-scale attenuation of dissolved contaminants.

  16. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  17. Suitability of tracers

    International Nuclear Information System (INIS)

    Klotz, D.

    1999-01-01

    Hydrological tracer techniques are a means of making statements on the direction and speed of underground water. One of the simpler tasks is to find out whether there is hydrological communication between two given points. This requires a determination of the direction of flow, which places less exacting demands on the properties of the tracer than does the task of determining the flow velocity of underground water. Tracer methods can serve to infer from flow velocity the distance (flow) velocity, which is defined as the ratio between the distance between two points located in flow direction and the actual time it takes water to flow from one to the other [de

  18. Comparison of three labeled silica nanoparticles used as tracers in transport experiments in porous media. Part II: Transport experiments and modeling

    International Nuclear Information System (INIS)

    Vitorge, Elsa; Szenknect, Stéphanie; Martins, Jean M.-F.; Barthès, Véronique; Gaudet, Jean-Paul

    2014-01-01

    Three types of labeled silica nanoparticles were used in transport experiments in saturated sand. The goal of this study was to evaluate both the efficiency of labeling techniques (fluorescence (FITC), metal (Ag(0) core) and radioactivity ( 110m Ag(0) core)) in realistic transport conditions and the reactive transport of silica nanocolloids of variable size and concentration in porous media. Experimental results obtained under contrasted experimental conditions revealed that deposition in sand is controlled by nanoparticles size and ionic strength of the solution. A mathematical model is proposed to quantitatively describe colloid transport. Fluorescent labeling is widely used to study fate of colloids in soils but was the less sensitive one. Ag(0) labeling with ICP-MS detection was found to be very sensitive to measure deposition profiles. Radiolabeled ( 110m Ag(0)) nanoparticles permitted in situ detection. Results obtained with radiolabeled nanoparticles are wholly original and might be used for improving the modeling of deposition and release dynamics. -- Highlights: • Three kinds of labeled nanotracers were used in transport experiments in sand columns. • They were used as surrogates of silica nanoparticles or mineral colloid. • Deposition depending on colloid size and ionic strength was observed and modeled. • Fluorescence labeling had the worse detection limit but was the more convenient. • Radiolabeled nanotracers were detected in situ in a non destructive way. -- Follow the kinetics of transport, deposition and release of silica nanoparticles with suitably labeled nanoparticles

  19. Numerical simulation of atmospheric dispersion in the vicinity of the Rocky Flats plant

    International Nuclear Information System (INIS)

    Bossert, J.E.; Poulos, G.S.

    1993-01-01

    The Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. In this study, we use the Regional Atmospheric Modeling System (RAMS) to simulate meteorological conditions and tracer dispersion on the case night of 4--5 February 1991. The simulations were developed to examine the influence of nocturnal drainage flow from various topography regimes on the dispersion of tracer from the Rocky Flats plant. The simulation described herein demonstrates the extent to which Rocky Mountain drainage winds influence the flow at the mountain/plain interface for a particular case night, and shows the potential importance of canyon drainage on dispersion from the Rocky Flats area

  20. New SPECT tracers: Example of tracers of proteoglycans and melanin

    International Nuclear Information System (INIS)

    Cachin, F.; Mestas, D.; Kelly, A.; Merlin, C.; Veyre, A.; Maublant, J.; Cachin, F.; Chezal, J.M.; Miot-Noirault, E.; Moins, N.; Auzeloux, P.; Vidal, A.; Bonnet-Duquennoy, M.; Boisgard, S.; D'Incan, M.; Madelmont, J.C.; Maublant, J.; Boisgard, S.; D'Incan, M.; Redini, F.; Filaire, M.

    2009-01-01

    The majority of research program on new radiopharmaceuticals turn to tracers used for positron emission tomography (PET). Only a few teams work on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma cameras should boost the development of non-PET tracers. We exhibit in this article the experience acquired by our laboratory in the conception and design of two new non fluorine labelled compounds. The 99m Tc-N.T.P. 15-5 (N.T.P. 15-5 for N-[tri-ethyl-ammonium]-3-propyl-[15]ane-N5) which binds to proteoglycans could be used for the diagnosis and staging of osteoarthritis and chondrosarcoma. The iodo benzamides, specific to the melanin, are nowadays compared to 18 F-fluorodeoxyglucose in a phase III clinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on N-[2-(diethyl-amino)ethyl]-4 and 2-iodo benzamides respectively B.Z.A. and B.Z.A.2 hetero-aromatic analogues usable for melanoma treatment. (authors)

  1. N-loss isotope effects in the Peru oxygen minimum zone studied using a mesoscale eddy as a natural tracer experiment

    Science.gov (United States)

    Bourbonnais, Annie; Altabet, Mark A.; Charoenpong, Chawalit N.; Larkum, Jennifer; Hu, Haibei; Bange, Hermann W.; Stramma, Lothar

    2015-06-01

    Mesoscale eddies in Oxygen Minimum Zones (OMZs) have been identified as important fixed nitrogen (N) loss hotspots that may significantly impact both the global rate of N-loss as well as the ocean's N isotope budget. They also represent "natural tracer experiments" with intensified biogeochemical signals that can be exploited to understand the large-scale processes that control N-loss and associated isotope effects (ɛ; the ‰ deviation from 1 in the ratio of reaction rate constants for the light versus heavy isotopologues). We observed large ranges in the concentrations and N and O isotopic compositions of nitrate (NO3-), nitrite (NO2-), and biogenic N2 associated with an anticyclonic mode-water eddy in the Peru OMZ during two cruises in November and December 2012. In the eddy's center where NO3- was nearly exhausted, we measured the highest δ15N values for both NO3- and NO2- (up to ~70‰ and 50‰) ever reported for an OMZ. Correspondingly, N deficit and biogenic N2-N concentrations were also the highest near the eddy's center (up to ~40 µmol L-1). δ15N-N2 also varied with biogenic N2 production, following kinetic isotopic fractionation during NO2- reduction to N2 and, for the first time, provided an independent assessment of N isotope fractionation during OMZ N-loss. We found apparent variable ɛ for NO3- reduction (up to ~30‰ in the presence of NO2-). However, the overall ɛ for N-loss was calculated to be only ~13-14‰ (as compared to canonical values of ~20-30‰) assuming a closed system and only slightly higher assuming an open system (16-19‰). Our results were similar whether calculated from the disappearance of DIN (NO3- + NO2-) or from the appearance of N2 and changes in isotopic composition. Further, we calculated the separate ɛ values for NO3- reduction to NO2- and NO2- reduction to N2 of ~16-21‰ and ~12‰, respectively, when the effect of NO2- oxidation could be removed. These results, together with the relationship between N and O of NO

  2. High Temperature, Controlled-Atmosphere Aerodynamic Levitation Experiments with Applications in Planetary Science

    Science.gov (United States)

    Macris, C. A.; Badro, J.; Eiler, J. M.; Stolper, E. M.

    2016-12-01

    The aerodynamic levitation laser apparatus is an instrument in which spherical samples are freely floated on top of a stream of gas while being heated with a CO2laser to temperatures up to about 3500 °C. Laser heated samples, ranging in size from 0.5 to 3.5 mm diameter, can be levitated in a variety of chemically active or inert atmospheres in a gas-mixing chamber (e.g., Hennet et al. 2006; Pack et al. 2010). This allows for containerless, controlled-atmosphere, high temperature experiments with potential for applications in earth and planetary science. A relatively new technique, aerodynamic levitation has been used mostly for studies of the physical properties of liquids at high temperatures (Kohara et al. 2011), crystallization behavior of silicates and oxides (Arai et al. 2004), and to prepare glasses from compositions known to crystallize upon quenching (Tangeman et al. 2001). More recently, however, aerodynamic levitation with laser heating has been used as an experimental technique to simulate planetary processes. Pack et al. (2010) used levitation and melting experiments to simulate chondrule formation by using Ar-H2 as the flow gas, thus imposing a reducing atmosphere, resulting in reduction of FeO, Fe2O3, and NiO to metal alloys. Macris et al. (2015) used laser heating with aerodynamic levitation to reproduce the textures and diffusion profiles of major and minor elements observed in impact ejecta from the Australasian strewn field, by melting a powdered natural tektite mixed with 60-100 μm quartz grains on a flow of pure Ar gas. These experiments resulted in quantitative modeling of Si and Al diffusion, which allowed for interpretations regarding the thermal histories of natural tektites and their interactions with the surrounding impact vapor plume. Future experiments will employ gas mixing (CO, CO2, H2, O, Ar) in a controlled atmosphere levitation chamber to explore the range of fO2applicable to melt-forming impacts on other rocky planetary bodies

  3. Tracer monitoring of enhanced oil recovery projects

    Directory of Open Access Journals (Sweden)

    Kleven R.

    2013-05-01

    Full Text Available In enhanced oil recovery (EOR, chemicals are injected into the oil reservoir, either to increase macroscopic sweep efficiency, or to reduce remaining oil saturation in swept zones. Tracers can be used to identify reservoirs that are specifically suited for EOR operations. Injection of a selection of partitioning tracers, combined with frequent sample analysis of produced fluids, provides information suited for estimation of residual oil saturation. Tracers can also be used to evaluate and optimize the application of EOR chemicals in the reservoir. Suitable tracers will follow the EOR chemicals and assist in evaluation of retention, degradation or trapping. In addition to field applications, tracers also have a large potential as a tool to perform mechanistic studies of EOR chemicals in laboratory experiments. By labelling EOR chemicals with radioactive isotopes of elements such as H, C and S, detailed studies of transport mechanisms can be carried out. Co-injection of labelled compounds in dynamic flooding experiments in porous media will give information about retention or separation of the unique compounds constituting the chemical formulation. Separation of such compounds may be detrimental to obtaining the EOR effect expected. The paper gives new information of specific methods, and discusses current status for use of tracers in EOR operations.

  4. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  5. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  6. Particle precipitation and atmospheric X-and gamma-rays in the South Atlantic magnetic anomaly by balloon experiments

    International Nuclear Information System (INIS)

    Costa, J.M. da.

    1981-06-01

    Studies concerning particle precipitation and atmospheric X-and low energy gamma-rays in the South Atlantic magnetic anomaly by balloons experiments that have been made at INPE since 1968 are reported. (Author) [pt

  7. Tracer techniques in microelectronics

    International Nuclear Information System (INIS)

    Flachowsky, J.; Freyer, K.

    1981-01-01

    Tracer technique and neutron activation analysis are capable of measuring impurities in semiconductor material or on the semiconductor surface in a very low concentration range. The methods, combined with autoradiography, are also suitable to determine dopant distributions in silicon. However, both techniques suffer from certain inherent experimental difficulties and/or limitations which are discussed. Methods of tracer technique practicable in the semiconductor field are described. (author)

  8. On the use of plant emitted volatile organic compounds for atmospheric chemistry simulation experiments

    Science.gov (United States)

    Kiendler-Scharr, A.; Hohaus, T.; Yu, Z.; Tillmann, R.; Kuhn, U.; Andres, S.; Kaminski, M.; Wegener, R.; Novelli, A.; Fuchs, H.; Wahner, A.

    2015-12-01

    Biogenic volatile organic compounds (BVOC) contribute to about 90% of the emitted VOC globally with isoprene being one of the most abundant BVOC (Guenther 2002). Intensive efforts in studying and understanding the impact of BVOC on atmospheric chemistry were undertaken in the recent years. However many uncertainties remain, e.g. field studies have shown that in wooded areas measured OH reactivity can often not be explained by measured BVOC and their oxidation products (e.g. Noelscher et al. 2012). This discrepancy may be explained by either a lack of understanding of BVOC sources or insufficient understanding of BVOC oxidation mechanisms. Plants emit a complex VOC mixture containing likely many compounds which have not yet been measured or identified (Goldstein and Galbally 2007). A lack of understanding BVOC sources limits bottom-up estimates of secondary products of BVOC oxidation such as SOA. Similarly, the widespread oversimplification of atmospheric chemistry in simulation experiments, using single compound or simple BVOC mixtures to study atmospheric chemistry processes limit our ability to assess air quality and climate impacts of BVOC. We will present applications of the new extension PLUS (PLant chamber Unit for Simulation) to our atmosphere simulation chamber SAPHIR. PLUS is used to produce representative BVOC mixtures from direct plant emissions. We will report on the performance and characterization of the newly developed chamber. As an exemplary application, trees typical of a Boreal forest environment were used to compare OH reactivity as directly measured by LIF to the OH reactivity calculated from BVOC measured by GC-MS and PTRMS. The comparison was performed for both, primary emissions of trees without any influence of oxidizing agents and using different oxidation schemes. For the monoterpene emitters investigated here, we show that discrepancies between measured and calculated total OH reactivity increase with increasing degree of oxidation

  9. Formation of amino acids and nucleotide bases in a Titan atmosphere simulation experiment.

    Science.gov (United States)

    Hörst, S M; Yelle, R V; Buch, A; Carrasco, N; Cernogora, G; Dutuit, O; Quirico, E; Sciamma-O'Brien, E; Smith, M A; Somogyi, A; Szopa, C; Thissen, R; Vuitton, V

    2012-09-01

    The discovery of large (>100 u) molecules in Titan's upper atmosphere has heightened astrobiological interest in this unique satellite. In particular, complex organic aerosols produced in atmospheres containing C, N, O, and H, like that of Titan, could be a source of prebiotic molecules. In this work, aerosols produced in a Titan atmosphere simulation experiment with enhanced CO (N(2)/CH(4)/CO gas mixtures of 96.2%/2.0%/1.8% and 93.2%/5.0%/1.8%) were found to contain 18 molecules with molecular formulae that correspond to biological amino acids and nucleotide bases. Very high-resolution mass spectrometry of isotopically labeled samples confirmed that C(4)H(5)N(3)O, C(4)H(4)N(2)O(2), C(5)H(6)N(2)O(2), C(5)H(5)N(5), and C(6)H(9)N(3)O(2) are produced by chemistry in the simulation chamber. Gas chromatography-mass spectrometry (GC-MS) analyses of the non-isotopic samples confirmed the presence of cytosine (C(4)H(5)N(3)O), uracil (C(5)H(4)N(2)O(2)), thymine (C(5)H(6)N(2)O(2)), guanine (C(5)H(5)N(5)O), glycine (C(2)H(5)NO(2)), and alanine (C(3)H(7)NO(2)). Adenine (C(5)H(5)N(5)) was detected by GC-MS in isotopically labeled samples. The remaining prebiotic molecules were detected in unlabeled samples only and may have been affected by contamination in the chamber. These results demonstrate that prebiotic molecules can be formed by the high-energy chemistry similar to that which occurs in planetary upper atmospheres and therefore identifies a new source of prebiotic material, potentially increasing the range of planets where life could begin.

  10. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    International Nuclear Information System (INIS)

    Kobayashi, Y.; Tsunesada, Y.; Tokuno, H.; Kakimoto, F.; Tomida, T.

    2011-01-01

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (X max ) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  11. Site characterization and validation - Tracer migration experiment in the validation drift, report 2, Part 2: breakthrough curves in the validation drift appendices 5-9

    International Nuclear Information System (INIS)

    Birgersson, L.; Widen, H.; Aagren, T.; Neretnieks, I.; Moreno, L.

    1992-01-01

    Flowrate curves for the 53 sampling areas in the validation drift with measureable flowrates are given. The sampling area 267 is treated as three separate sampling areas; 267:1, 267:2 and 267:3. The total flowrate for these three sampling areas is given in a separate plot. The flowrates are given in ml/h. The time is given in hours since April 27 00:00, 1990. Disturbances in flowrates are observed after 8500 hours due to opening of boreholes C1 and W1. Results from flowrate measurements after 8500 hours are therefore excluded. The tracer breakthrough curves for 38 sampling areas in the validation drift are given as concentration values versus time. The sampling area 267 is treated as three separate sampling areas; 267:1, 267:2 and 267:3. This gives a total of 40 breakthrough curves for each tracer. (au)

  12. The possibility to observe the non-standard interaction by the Hyperkamiokande atmospheric neutrino experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fukasawa, Shinya; Yasuda, Osamu, E-mail: yasuda@phys.se.tmu.ac.jp

    2017-01-15

    It was suggested that a tension between the mass-squared differences obtained from the solar neutrino and KamLAND experiments can be solved by introducing the non-standard flavor-dependent interaction in neutrino propagation. In this paper we discuss the possibility to test such a hypothesis by atmospheric neutrino observations at the future Hyper-Kamiokande experiment. Assuming that the mass hierarchy is known, we find that the best-fit value from the solar neutrino and KamLAND data can be tested at more than 8σ, while the one from the global analysis can be examined at 5.0σ (1.4σ) for the normal (inverted) mass hierarchy.

  13. Impact of small-scale saline tracer heterogeneity on electrical resistivity monitoring in fully and partially saturated porous media: Insights from geoelectrical milli-fluidic experiments

    Science.gov (United States)

    Jougnot, Damien; Jiménez-Martínez, Joaquín; Legendre, Raphaël; Le Borgne, Tanguy; Méheust, Yves; Linde, Niklas

    2018-03-01

    Time-lapse electrical resistivity tomography (ERT) is a geophysical method widely used to remotely monitor the migration of electrically-conductive tracers and contaminant plumes in the subsurface. Interpretations of time-lapse ERT inversion results are generally based on the assumption of a homogeneous solute concentration below the resolution limits of the tomogram depicting inferred electrical conductivity variations. We suggest that ignoring small-scale solute concentration variability (i.e., at the sub-resolution scale) is a major reason for the often-observed apparent loss of solute mass in ERT tracer studies. To demonstrate this, we developed a geoelectrical milli-fluidic setup where the bulk electric conductivity of a 2D analogous porous medium, consisting of cylindrical grains positioned randomly inside a Hele-Shaw cell, is monitored continuously in time while saline tracer tests are performed through the medium under fully and partially saturated conditions. High resolution images of the porous medium are recorded with a camera at regular time intervals, and provide both the spatial distribution of the fluid phases (aqueous solution and air), and the saline solute concentration field (where the solute consists of a mixture of salt and fluorescein, the latter being used as a proxy for the salt concentration). Effective bulk electrical conductivities computed numerically from the measured solute concentration field and the spatial distributions of fluid phases agree well with the measured bulk conductivities. We find that the effective bulk electrical conductivity is highly influenced by the connectivity of high electrical conductivity regions. The spatial distribution of air, saline tracer fingering, and mixing phenomena drive temporal changes in the effective bulk electrical conductivity by creating preferential paths or barriers for electrical current at the pore-scale. The resulting heterogeneities in the solute concentrations lead to strong anisotropy

  14. Tracers of air-sea gas exchange

    International Nuclear Information System (INIS)

    Liss, P.S.

    1988-01-01

    The flux of gas across the air-sea interface is determined by the product of the interfacial concentration difference driving the exchange and a rate constant, often termed the transfer velocity. The concentration-difference term is generally obtained by direct measurement, whereas more indirect approaches are required to estimate the transfer velocity and its variation as a function of controlling parameters such as wind and sea state. Radioactive tracers have proved particularly useful in the estimation of air-sea transfer velocities and, recently, stable purposeful tracers have also started to be used. In this paper the use of the following tracers to determine transfer velocities at the sea surface is discussed: natural and bomb-produced 14 C, dissolved oxygen, 222 Rn and sulphur hexafluoride. Other topics covered include the relation between transfer velocity and wind speed as deduced from tracer and wind-tunnel studies, and the discrepancy between transfer velocities determined by using tracers and from eddy correlation measurements in the atmosphere. (author)

  15. Ammonium and nitrate uptake lengths in a small forested stream determined by {sup 15}N tracer and short-term nutrient enrichment experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P.J.; Tank, J.L.; Sanzone, D.M.; Webster, J.R.; Wollheim, W.; Peterson, B.J.; Meyer, J.L.

    1998-11-01

    Nutrient cycling is an important characteristic of all ecosystems, including streams. Nutrients often limit the growth rates of stream algae and heterotrophic microbes and the decomposition rate of allochthonous organic matter. Nutrient uptake (S{sub W}), defined as the mean distance traveled by a nutrient atom dissolved in stream water before uptake by biota is often used as an index of nutrient cycling in streams. It is often overlooked, however, that S{sub W} is not a measure of nutrient uptake rate per se, but rather a measure of the efficiency with which a stream utilizes the available nutrient supply. The ideal method for measuring S{sub W} involves short-term addition of a nutrient tracer. Regulatory constraints often preclude use of nutrient radiotracers in field studies and methodological difficulties and high analytical costs have previously hindered the use of stable isotope nutrient tracers (e.g., {sup 15}N). Short-term nutrient enrichments are an alternative to nutrient tracer additions for measuring S{sub W}.

  16. Experience with novel technologies for direct measurement of atmospheric NO2

    Science.gov (United States)

    Hueglin, Christoph; Hundt, Morten; Mueller, Michael; Schwarzenbach, Beat; Tuzson, Bela; Emmenegger, Lukas

    2017-04-01

    Nitrogen dioxide (NO2) is an air pollutant that has a large impact on human health and ecosystems, and it plays a key role in the formation of ozone and secondary particulate matter. Consequently, legal limit values for NO2 are set in the EU and elsewhere, and atmospheric observation networks typically include NO2 in their measurement programmes. Atmospheric NO2 is principally measured by chemiluminescence detection, an indirect measurement technique that requires conversion of NO2 into nitrogen monoxide (NO) and finally calculation of NO2 from the difference between total nitrogen oxides (NOx) and NO. Consequently, NO2 measurements with the chemiluminescence method have a relatively high measurement uncertainty and can be biased depending on the selectivity of the applied NO2 conversion method. In the past years, technologies for direct and selective measurement of NO2 have become available, e.g. cavity attenuated phase shift spectroscopy (CAPS), cavity enhanced laser absorption spectroscopy and quantum cascade laser absorption spectrometry (QCLAS). These technologies offer clear advantages over the indirect chemiluminescence method. We tested the above mentioned direct measurement techniques for NO2 over extended time periods at atmospheric measurement stations and report on our experience including comparisons with co-located chemiluminescence instruments equipped with molybdenum as well as photolytic NO2 converters. A still open issue related to the direct measurement of NO2 is instrument calibration. Accurate and traceable reference standards and NO2 calibration gases are needed. We present results from the application of different calibration strategies based on the use of static NO2 calibration gases as well as dynamic NO2 calibration gases produced by permeation and by gas-phase titration (GPT).

  17. Ground-based acoustic parametric generator impact on the atmosphere and ionosphere in an active experiment

    Directory of Open Access Journals (Sweden)

    Y. G. Rapoport

    2017-01-01

    Full Text Available We develop theoretical basics of active experiments with two beams of acoustic waves, radiated by a ground-based sound generator. These beams are transformed into atmospheric acoustic gravity waves (AGWs, which have parameters that enable them to penetrate to the altitudes of the ionospheric E and F regions where they influence the electron concentration of the ionosphere. Acoustic waves are generated by the ground-based parametric sound generator (PSG at the two close frequencies. The main idea of the experiment is to design the output parameters of the PSG to build a cascade scheme of nonlinear wave frequency downshift transformations to provide the necessary conditions for their vertical propagation and to enable penetration to ionospheric altitudes. The PSG generates sound waves (SWs with frequencies f1 = 600 and f2 = 625 Hz and large amplitudes (100–420 m s−1. Each of these waves is modulated with the frequency of 0.016 Hz. The novelty of the proposed analytical–numerical model is due to simultaneous accounting for nonlinearity, diffraction, losses, and dispersion and inclusion of the two-stage transformation (1 of the initial acoustic waves to the acoustic wave with the difference frequency Δf = f2 − f1 in the altitude ranges 0–0.1 km, in the strongly nonlinear regime, and (2 of the acoustic wave with the difference frequency to atmospheric acoustic gravity waves with the modulational frequency in the altitude ranges 0.1–20 km, which then reach the altitudes of the ionospheric E and F regions, in a practically linear regime. AGWs, nonlinearly transformed from the sound waves, launched by the two-frequency ground-based sound generator can increase the transparency of the ionosphere for the electromagnetic waves in HF (MHz and VLF (kHz ranges. The developed theoretical model can be used for interpreting an active experiment that includes the PSG impact on the atmosphere–ionosphere system

  18. A global high-resolution model experiment on the predictability of the atmosphere

    Science.gov (United States)

    Judt, F.

    2016-12-01

    Forecasting high-impact weather phenomena is one of the most important aspects of numerical weather prediction (NWP). Over the last couple of years, a tremendous increase in computing power has facilitated the advent of global convection-resolving NWP models, which allow for the seamless prediction of weather from local to planetary scales. Unfortunately, the predictability of specific meteorological phenomena in these models is not very well known. This raises questions about which forecast problems are potentially tractable, and what is the value of global convection-resolving model predictions for the end user. To address this issue, we use the Yellowstone supercomputer to conduct a global high-resolution predictability experiment with the recently developed Model for Prediction Across Scales (MPAS). The computing power of Yellowstone enables the model to run at a globally uniform resolution of 4 km with 55 vertical levels (>2 billion grid cells). These simulations, which require 3 million core-hours for the entire experiment, allow for the explicit treatment of organized deep moist convection (i.e., thunderstorm systems). Resolving organized deep moist convection alleviates grave limitations of previous predictability studies, which either used high-resolution limited-area models or global simulations with coarser grids and cumulus parameterization. By computing the error growth characteristics in a set of "identical twin" model runs, the experiment will clarify the intrinsic predictability limits of atmospheric phenomena on a wide range of scales, from severe thunderstorms to global-scale wind patterns that affect the distribution of tropical rainfall. Although a major task by itself, this study is intended to be exploratory work for a future predictability experiment going beyond of what has so far been feasible. We hope to use CISL's new Cheyenne supercomputer to conduct a similar predictability experiments on a global mesh with 1-2 km resolution. This

  19. Model experiment on detection and monitoring of fractures by using air as a tracer for seismic wave. 2; Kitai wo tracer to shita kiretsu no danseiha tansa no model jikken. 2

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T; Takami, Y; Ishiga, T; Sassa, K [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-05-01

    Clearance provided between two flat resin blocks (being stacked) used as a model of a crack in rocks was subjected to an experiment to investigate elastic wave propagation characteristics when the crack is filled with water and when injected with air. This paper reports the result of the experiment. The experiment was carried out on a case where a parallel flat layer of water (with a thickness of 2 mm) was used as a crack and a case where crack faces are contacted (small resin pieces are inserted into the crack). The experiment was conducted by injecting air bubbles (air) into the water saturated crack from its side to gradually expand the air bubble existing region. Seven ceramic piezoelectric elements (one is a vibration source) were arranged on top of a resin block and six elements beneath the block to measure a wave reflected from the crack face and a wave permeated through the crack. It was found that as the air bubble existing region is expanded, the amplitude of the permeated wave decreases remarkably (however, only to a certain level when the crack faces are contacted), and the amplitude of the reflected wave increases. 3 refs., 9 figs.

  20. Wairakei tracer tests 1983

    International Nuclear Information System (INIS)

    McCabe, W.J.; Barry, B.J.

    1984-05-01

    Tracer tests, with and without, hot water reinjection into WK213 showed returns of tracer iodine-131; in wells in both the Waiora Valley and the eastern end of the field. The effect of reinjection at a rate of 200 cu. m/h was to reduce the arrived time from 15 to 7 days. Increasing the rate of reinjection into WK62 from 30 cu. m/h to 200 cu. m/h seemed to increase the initial velocity of the tracer wave and the distance it moved. However, returns were recorded only in the adjacent wells WK61 and WK63 with a very small, and three days delayed, response in WK43

  1. A Long-term Forest Fertilization Experiment to Understand Ecosystem Responses to Atmospheric Nitrogen Deposition

    Science.gov (United States)

    Baron, J.; Advani, S. M.; Allen, J.; Boot, C.; Denef, K.; Denning, S.; Hall, E.; Moore, J. C.; Reuth, H.; Ryan, M. G.; Shaw, E.

    2016-12-01

    Long-term field experiments can reveal changes in ecosystem processes that may not be evident in short-term studies. Short-term measurements or experiments may have narrower objectives or unrealistic treatments in order to see a change, whereas long-term studies can reveal complex interactions that take longer to manifest. We report results from a long-term experiment (1996 to present) in subalpine forests to simulate the consequences of sustained atmospheric nitrogen (N) deposition. Loch Vale watershed in Rocky Mountain National Park, the location of the experiment, has received an order of magnitude greater atmospheric N deposition than estimated background since mid-20th Century. Augmenting that, in 1996 we began adding 25 kg NH4NO3 ha-1 yr-1 to three 30m x 30m old-growth Engelmann spruce and subalpine fir plots. Treated stands were matched by nearby controls. N addition caused rapid leaching of nitrate and cations from soils, and increased N mineralization and nitrification rates. These observations in the fertilized plots have been sustained over time. Soluble aluminum concentrations do not differ significantly between fertilized and control plots, but treated soils are now markedly more acidic (pH of 4.7) than original soil and controls (pH of 5.1); further acidification might increase aluminum leaching. Effects on soil carbon were complex, mediated by reductions in total microbial biomass, decreases in arbuscular mychorrizal and saprotropic fungi, and increased potential rates of N enzyme degrading activities. Initial soil C:N of 24 was lower than similar soils in low N deposition stands (C:N of 36). The C:N declined to 22 with treatment. Fertilized plots lost 11% soil C, but the mechanism is unclear. We did not measure changes in C inputs from litter, microbial biomass, or plant uptake, but there was no change in summer CO2 flux, measured in 2003, 2004, and 2014. Leaching of DOC from fertilized plots was elevated throughout the experiment, providing one

  2. Experiment and modeling of an atmospheric pressure arc in an applied oscillating magnetic field

    International Nuclear Information System (INIS)

    Karasik, Max; Roquemore, A. L.; Zweben, S. J.

    2000-01-01

    A set of experiments are carried out to measure and understand the response of a free-burning atmospheric pressure carbon arc to applied transverse dc and ac magnetic fields. The arc is found to deflect parabolically for the dc field and assumes a growing sinusoidal structure for the ac field. A simple analytic two-parameter fluid model of the arc dynamics is derived, in which the arc response is governed by the arc jet originating at the cathode, with the applied JxB force balanced by inertia. Time variation of the applied field allows evaluation of the parameters individually. A fit of the model to the experimental data gives a value for the average jet speed an order of magnitude below Maecker's estimate of the maximum jet speed [H. Maecker, Z. Phys. 141, 198 (1955)]. An example industrial application of the model is considered. (c) 2000 American Institute of Physics

  3. A stratospheric balloon experiment to test the Huygens atmospheric structure instrument (HASI)

    Science.gov (United States)

    Fulchignoni, M.; Aboudan, A.; Angrilli, F.; Antonello, M.; Bastianello, S.; Bettanini, C.; Bianchini, G.; Colombatti, G.; Ferri, F.; Flamini, E.; Gaborit, V.; Ghafoor, N.; Hathi, B.; Harri, A.-M.; Lehto, A.; Lion Stoppato, P. F.; Patel, M. R.; Zarnecki, J. C.

    2004-08-01

    We developed a series of balloon experiments parachuting a 1:1 scale mock-up of the Huygens probe from an altitude just over 30 km to simulate at planetary scale the final part of the descent of the probe through Titan's lower atmosphere. The terrestrial atmosphere represents a natural laboratory where most of the physical parameters meet quite well the bulk condition of Titan's environment, in terms of atmosphere composition, pressure and mean density ranges, though the temperature range will be far higher. The probe mock-up consists of spares of the HASI sensor packages, housekeeping sensors and other dedicated sensors, and also incorporates the Huygens Surface Science Package (SSP) Tilt sensor and a modified version of the Beagle 2 UV sensor, for a total of 77 acquired sensor channels, sampled during ascent, drift and descent phase. An integrated data acquisition and instrument control system, simulating the HASI data-processing unit (DPU), has been developed, based on PC architecture and soft-real-time application. Sensor channels were sampled at the nominal HASI data rates, with a maximum rate of 1 kHz. Software has been developed for data acquisition, onboard storage and telemetry transmission satisfying all requests for real-time monitoring, diagnostic and redundancy. The mock-up of the Huygens probe mission was successfully launched for the second time (first launch in summer 2001, see Gaborit et al., 2001) with a stratospheric balloon from the Italian Space Agency Base "Luigi Broglio" in Sicily on May 30, 2002, and recovered with all sensors still operational. The probe was lifted to an altitude of 32 km and released to perform a parachuted descent lasting 53 min, to simulate the Huygens mission at Titan. Preliminary aerodynamic study of the probe has focused upon the achievement of a descent velocity profile reproducing the expected profile of Huygens probe descent into Titan. We present here the results of this experiment discussing their relevance in

  4. Green River air quality model development: meteorological and tracer data, July/August 1982 field study in Brush Valley, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Whiteman, C.D.; Lee, R.N.; Orgill, M.M.; Zak, B.D.

    1984-06-01

    Meteorological and atmospheric tracer studies were conducted during a 3-week period in July and August of 1982 in the Brush Creek Valley of northwestern Colorado. The objective of the field experiments was to obtain data to evaluate a model, called VALMET, developed at PNL to predict dispersion of air pollutants released from an elevated stack located within a deep mountain valley in the post-sunrise temperature inversion breakup period. Three tracer experiments were conducted in the valley during the 2-week period. In these experiments, sulfur hexafluoride (SF/sub 6/) was released from a height of approximately 100 m, beginning before sunrise and continuing until the nocturnal down-valley winds reversed several hours after sunrise. Dispersion of the sulfur hexafluoride after release was evaluated by measuring SF/sub 6/ concentrations in ambient air samples taken from sampling devices operated within the valley up to about 8 km down valley from the source. An instrumented research aircraft was also used to measure concentrations in and above the valley. Tracer samples were collected using a network of radio-controlled bag sampling stations, two manually operated gas chromatographs, a continuous SF/sub 6/ monitor, and a vertical SF/sub 6/ profiler. In addition, basic meteorological data were collected during the tracer experiments. Frequent profiles of vertical wind and temperature structure were obtained with tethered balloons operated at the release site and at a site 7.7 km down the valley from the release site. 10 references, 63 figures, 50 tables.

  5. Haze production rates in super-Earth and mini-Neptune atmosphere experiments

    Science.gov (United States)

    Hörst, Sarah M.; He, Chao; Lewis, Nikole K.; Kempton, Eliza M.-R.; Marley, Mark S.; Morley, Caroline V.; Moses, Julianne I.; Valenti, Jeff A.; Vuitton, Véronique

    2018-04-01

    Numerous Solar System atmospheres possess photochemically generated hazes, including the characteristic organic hazes of Titan and Pluto. Haze particles substantially impact atmospheric temperature structures and may provide organic material to the surface of a world, potentially affecting its habitability. Observations of exoplanet atmospheres suggest the presence of aerosols, especially in cooler (diversity in haze production rates, as some—but not all—super-Earth and mini-Neptune atmospheres will possess photochemically generated haze.

  6. Evaluation of main control room habitability in Japanese LWR (2). Evaluation for applicability of existing atmospheric dispersion models to building wake dispersion by using wind tunnel experiment

    International Nuclear Information System (INIS)

    Fukuda, Ryo; Fujita, Yuko; Yoneda, Jiro; Okabayashi, Kazuki; Tabuse, Shigehiko; Watada, Masayuki

    2009-01-01

    It is necessary to predict the concentration field behind the containment vessel building for the evaluation of main control room habitability in case of the emergency. The concentration field behind the building is very complicated phenomena and the exact prediction of concentration would be very difficult even if philosophical numerical simulation was used. Instead the simple and analytical prediction models (ARCON96, Gifford and Murphy-Campe etc.) have been used for the assessment of main control room habitability. In order to evaluate the previous models, the wind tunnel experiment was carried out. Recent regulatory models of ADMS4 developed by UK-CERC and AERMOD by US-EPA were also compared with this experimental data. Only both the containment vessel and reactor buildings of the typical PWR plant was scaled in 1/200 and the atmospheric stability C-D between C and D of Pasquill-Gifford categories was reproduced as a neutral condition in the wind tunnel experiment. In the wind experiment, the meandering effect for 1 hour was taken into consideration by the so-called overlapping method that a scaled model in the test section of a wind tunnel was rotated. By the rotation of the scaled model, wind directional fluctuations were relatively generated in the test section. The model was rotated at a various speed which was inversely proportional to each frequency of occurrence of a wind direction. Tracer gas was sampled during the rotation of the building model. As a result, we got the 1 hr.-averaged concentration taking a meandering effect into consideration. In this experiment, it is assumed that the frequency distribution of wind direction is Gaussian and horizontal plume width for 1 hr. was expanded to about 1.8 times of plume width based on Pasquill-Gifford chart by 1/5 power law due to the meandering effect. From the experiment, it was found as follows; It seems that meandering effect was not important in the near field behind a building, because strong

  7. The Atmospheric Waves Experiment (AWE): Quantifying the Impact of Gravity Waves on the Edge of Space

    Science.gov (United States)

    Taylor, M. J.; Forbes, J. M.; Fritts, D. C.; Eckermann, S. D.; Snively, J. B.; Liu, H.; Janches, D.; Syrstad, E. A.; Esplin, R. W.; Pautet, P. D.; Zhao, Y.; Pendleton, W. R.

    2017-12-01

    New theory and modeling now indicate that upward-propagating gravity waves (GWs) originating in the lower atmosphere have profound effects on the variability and mean state of the ionosphere-thermosphere-mesosphere (ITM) system. A major unknown is the spectrum of small-scale ( 30-300 km) GWs entering this system from below. Yet, this part of the spectrum contains most of the waves that will produce the greatest ITM effects. To address this knowledge gap, the Atmospheric Waves Experiment (AWE) plans to deploy a high-resolution imager (based on the successful Utah State University Advanced Mesospheric Temperature Mapper) on the International Space Station (ISS) to gain a transformative set of GW-resolving temperature measurements using the OH nightglow emission (altitude 87 km). The ISS provides the ideal combination of altitude, geographic and local time coverage to accomplish our proposed science objectives, which seeks not only near-global measurements of GW characteristics in the mesopause region, but also quantification of GW momentum and energy fluxes driving the IT from below. Combined with state-of-the-art high-resolution models, the AWE mission will also assess the relative importance of sources versus propagation conditions in explaining the observed spatial and temporal variability of the GWs. The AWE mission was recently selected for a "Phase A" study as part of the NASA 2016 Heliophysics Explorers Mission of Opportunity (MO) Program. In this presentation, we describe the primary goals of this program and introduce our proposed research methods using proven IR instrument technology. AWE's exceptional capabilities are illustrated with recent discoveries in observing GWs from the ground and from aircraft during the NSF DEEPWAVE campaign, promising a major step forward in understanding how troposphere weather translates to space weather.

  8. CalWater 2 - Precipitation, Aerosols, and Pacific Atmospheric Rivers Experiment

    Science.gov (United States)

    Spackman, J. R.; Ralph, F. M.; Prather, K. A.; Cayan, D. R.; DeMott, P. J.; Dettinger, M. D.; Fairall, C. W.; Leung, L. R.; Rosenfeld, D.; Rutledge, S. A.; Waliser, D. E.; White, A. B.

    2014-12-01

    Emerging research has identified two phenomena that play key roles in the variability of the water supply and the incidence of extreme precipitation events along the West Coast of the United States. These phenomena include the role of (1) atmospheric rivers (ARs) in delivering much of the precipitation associated with major storms along the U.S. West Coast, and (2) aerosols—from local sources as well as those transported from remote continents—and their modulating effects on western U.S. precipitation. A better understanding of these processes is needed to reduce uncertainties in weather predictions and climate projections of extreme precipitation and its effects, including the provision of beneficial water supply. This presentation summarizes the science objectives and strategies to address gaps associated with (1) the evolution and structure of ARs including cloud and precipitation processes and air-sea interaction, and (2) aerosol interaction with ARs and the impact on precipitation, including locally-generated aerosol effects on orographic precipitation along the U.S. West Coast. Observations are proposed for multiple winter seasons as part of a 5-year broad interagency vision referred to as CalWater 2 to address these science gaps (http://esrl.noaa.gov/psd/calwater). In January-February 2015, a field campaign has been planned consisting of a targeted set of aircraft and ship-based measurements and associated evaluation of data in near-shore regions of California and in the eastern Pacific. In close coordination with NOAA, DOE's Atmospheric Radiation Measurement (ARM) program is also contributing air and shipborne facilities for ACAPEX (ARM Cloud Aerosol and Precipitation Experiment), a DOE-sponsored study complementing CalWater 2. Ground-based measurements from NOAA's HydroMeteorological Testbed (HMT) network in California and aerosol chemical instrumentation at Bodega Bay, California have been designed to add important near surface-level context for the

  9. Structure of the marine atmospheric boundary layer over an oceanic thermal front: SEMAPHORE experiment

    Science.gov (United States)

    Kwon, B. H.; BéNech, B.; Lambert, D.; Durand, P.; Druilhet, A.; Giordani, H.; Planton, S.

    1998-10-01

    The Structure des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, the third phase of which took place between October 4 and November 17, 1993, was conducted over the oceanic Azores Current located in the Azores basin and mainly marked at the surface by a thermal front due to the gradient of the sea surface temperature (SST) of about 1° to 2°C per 100 km. The evolution of the marine atmospheric boundary layer (MABL) over the SST front was studied with two aircraft and a ship in different meteorological conditions. For each case, the influence of the incoming air direction with respect to the orientation of the oceanic front was taken into account. During the campaign, advanced very high resolution radiometer pictures did not show any relation between the SST field and the cloud cover. The MABL was systematically thicker on the warm side than on the cold side. The mean MABL structure described from aircraft data collected in a vertical plane crossing the oceanic front was characterized by (1) an atmospheric horizontal gradient of 1° to 2°C per 100 km in the whole depth of the mixed layer and (2) an increase of the wind intensity from the cold to the warm side when the synoptic wind blew from the cold side. The surface sensible heat (latent heat) flux always increased from the cold to the warm sector owing to the increase of the wind and of the temperature (specific humidity) difference between the surface and the air. Turbulence increased from the cold to the warm side in conjunction with the MABL thickening, but the normalized profiles presented the same structure, regardless of the position over the SST front. In agreement with the Action de Recherche Programme te Petite Echelle and Grande Echelle model, the mean temperature and momentum budgets were highly influenced by the horizontal temperature gradient. In particular, the strong ageostrophic influence in the MABL above the SST front seems

  10. Atmospheric transport simulations in support of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE)

    Science.gov (United States)

    Henderson, J. M.; Eluszkiewicz, J.; Mountain, M. E.; Nehrkorn, T.; Chang, R. Y.-W.; Karion, A.; Miller, J. B.; Sweeney, C.; Steiner, N.; Wofsy, S. C.; Miller, C. E.

    2015-04-01

    This paper describes the atmospheric modeling that underlies the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) science analysis, including its meteorological and atmospheric transport components (polar variant of the Weather Research and Forecasting (WRF) and Stochastic Time Inverted Lagrangian Transport (STILT) models), and provides WRF validation for May-October 2012 and March-November 2013 - the first 2 years of the aircraft field campaign. A triply nested computational domain for WRF was chosen so that the innermost domain with 3.3 km grid spacing encompasses the entire mainland of Alaska and enables the substantial orography of the state to be represented by the underlying high-resolution topographic input field. Summary statistics of the WRF model performance on the 3.3 km grid indicate good overall agreement with quality-controlled surface and radiosonde observations. Two-meter temperatures are generally too cold by approximately 1.4 K in 2012 and 1.1 K in 2013, while 2 m dewpoint temperatures are too low (dry) by 0.2 K in 2012 and too high (moist) by 0.6 K in 2013. Wind speeds are biased too low by 0.2 m s-1 in 2012 and 0.3 m s-1 in 2013. Model representation of upper level variables is very good. These measures are comparable to model performance metrics of similar model configurations found in the literature. The high quality of these fine-resolution WRF meteorological fields inspires confidence in their use to drive STILT for the purpose of computing surface influences ("footprints") at commensurably increased resolution. Indeed, footprints generated on a 0.1° grid show increased spatial detail compared with those on the more common 0.5° grid, better allowing for convolution with flux models for carbon dioxide and methane across the heterogeneous Alaskan landscape. Ozone deposition rates computed using STILT footprints indicate good agreement with observations and exhibit realistic seasonal variability, further indicating that WRF

  11. Gravity Waves in the Atmosphere of Mars as seen by the Radio Science Experiment MaRS on Mars Express

    Science.gov (United States)

    Tellmann, S.; Paetzold, M.; Häusler, B.; Bird, M. K.; Tyler, G. L.; Hinson, D. P.

    2016-12-01

    Gravity waves are atmospheric waves whose restoring force is the buoyancy. They are known to play an essential role in the redistribution of energy, momentum and atmospheric constituents in all stably stratified planetary atmospheres. Possible excitation mechanisms comprise convection in an adjacent atmospheric layer, other atmospheric instabilities like wind shear instabilities, or air flow over orographic obstacles especially in combination with the strong winter jets on Mars. Gravity waves on Mars were observed in the lower atmosphere [1,2] but are also expected to play a major role in the cooling of the thermosphere [3] and the polar warming [4]. A fundamental understanding of the possible source mechanisms is required to reveal the influence of small scale gravity waves on the global atmospheric circulation. Radio occultation profiles from the MaRS experiment on Mars Express [5] with their exceptionally high vertical resolution can be used to study small-scale vertical gravity waves and their global distribution in the lower atmosphere from the planetary boundary layer up to 40 km altitude. Atmospheric instabilities, which are clearly identified in the data, are used to gain further insight into possible atmospheric processes contributing to the excitation of gravity waves. [1] Creasey, J. E., et al.,(2006), Geophys. Res. Lett., 33, L01803, doi:10.1029/2005GL024037. [2]Tellmann, S., et al.(2013), J. Geophys. Res. Planets, 118, 306-320, doi:10.1002/jgre.20058. [3]Medvedev, A. S., et al.(2015), J. Geophys. Res. Planets, 120, 913-927. doi:10.1002/2015JE004802.[4] Barnes, J. R. (1990), J. Geophys. Res., 95, B2, 1401-1421. [5] Pätzold, M., et al. (2016), Planet. Space Sci., 127, 44 - 90.

  12. Rate tracer studies of heterogeneous catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Happel, J; Kiang, S

    1977-10-01

    An analysis is presented of the extent to which parameters involved in transient tracing of isotopic species in heterogeneous catalysis can be determined by experiments in which tracer concentrations are measured as a function of time. Different treatments for open and closed systems with the over-all reaction at equilibrium or irreversible were developed.

  13. Tracer gas diffusion sampling test plan

    International Nuclear Information System (INIS)

    Rohay, V.J.

    1993-01-01

    Efforts are under way to employ active and passive vapor extraction to remove carbon tetrachloride from the soil in the 200 West Area an the Hanford Site as part of the 200 West Area Carbon Tetrachloride Expedited Response Action. In the active approach, a vacuum is applied to a well, which causes soil gas surrounding the well to be drawn up to the surface. The contaminated air is cleaned by passage through a granular activated carbon bed. There are questions concerning the radius of influence associated with application of the vacuum system and related uncertainties about the soil-gas diffusion rates with and without the vacuum system present. To address these questions, a series of tracer gas diffusion sampling tests is proposed in which an inert, nontoxic tracer gas, sulfur hexafluoride (SF 6 ), will be injected into a well, and the rates of SF 6 diffusion through the surrounding soil horizon will be measured by sampling in nearby wells. Tracer gas tests will be conducted at sites very near the active vacuum extraction system and also at sites beyond the radius of influence of the active vacuum system. In the passive vapor extraction approach, barometric pressure fluctuations cause soil gas to be drawn to the surface through the well. At the passive sites, the effects of barometric ''pumping'' due to changes in atmospheric pressure will be investigated. Application of tracer gas testing to both the active and passive vapor extraction methods is described in the wellfield enhancement work plan (Rohay and Cameron 1993)

  14. Xanthine tracers and their preparation

    International Nuclear Information System (INIS)

    Groman, E.V.; Cabelli, M.D.

    1980-01-01

    Compounds useful as tracers in the radioimmunoassay of xanthine derivatives such as theophylline and pharmacologically related drugs are described. They are substituted xanthines in which at least one substituted radical contains radioiodine. The tracers are made by linking radioiodinatable or preradioiodinated radicals to the xanthine derivative which is to be assayed. The tracers may be employed in known radioimmunoassay techniques. (author)

  15. Zero-Gravity Atmospheric Cloud Physics Experiment Laboratory engineering concepts/design tradeoffs. Volume 1: Study results

    Science.gov (United States)

    Greco, R. V.; Eaton, L. R.; Wilkinson, H. C.

    1974-01-01

    The work is summarized which was accomplished from January 1974 to October 1974 for the Zero-Gravity Atmospheric Cloud Physics Laboratory. The definition and development of an atmospheric cloud physics laboratory and the selection and delineation of candidate experiments that require the unique environment of zero gravity or near zero gravity are reported. The experiment program and the laboratory concept for a Spacelab payload to perform cloud microphysics research are defined. This multimission laboratory is planned to be available to the entire scientific community to utilize in furthering the basic understanding of cloud microphysical processes and phenomenon, thereby contributing to improved weather prediction and ultimately to provide beneficial weather control and modification.

  16. THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience.

    Science.gov (United States)

    Baum, Richard P; Kulkarni, Harshad R

    2012-01-01

    The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

  17. THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience

    Directory of Open Access Journals (Sweden)

    Richard P. Baum, Harshad R. Kulkarni

    2012-01-01

    Full Text Available The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET, single photon emission computed tomography (SPECT, magnetic resonance imaging (MRI, or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT, and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

  18. New experience in atmospheric monitoring in Moscow city on the base of WSN technology

    Science.gov (United States)

    Asavin, Alex; Litvinov, Artur; Baskakov, Sergey; Chesalova, Elena

    2016-04-01

    on the each calibration graphics with different H2 concentration in standard gas mixtures. The graphics represent the power functions. The accuracy of the approximating functions is 3-18 %. At low concentrations (H2 Communication between router and IT server used two methods: cable RS486 and GPRS modem. GPRS connection is unstable and influence on operating stability. There are some problems in using of directional antenna because of the high level of city's radio noises and radio interferences. Nevertheless, a number of experiments with use of different technical solutions allowed us to perform continuous monitoring during 2 months. As a result about 3 million data records were obtained during experimental works. This information provided an opportunity to develop the structure of database management systems to store data and the technology of online data collection from remote sensors. Using the abilities of program software a periodical (12h) automatic export/import was realized. Access to file on remote computers is opened using FTP protocol. Database forms derived tables for each sensors. We use triggers to modify data, for example, to modify signal from gas sensors to gas concentration, in depend of unique sensor name. Additional table gives geographical coordinates of each node. We use GIS project for visualization and data analysis. Experiences revealed the inverse relationship between H2 concentration and temperature and pressure. Also we revealed periodicity of gas concentration with different harmonics. We could not find in literatures the similar works of H2 monitoring in cites. Exclusion is the work of (Necki et al., 2014) to organize continue monitoring in Krakow and it neighborhood. Authors also note periodicity in gas concentration affected by the seasons (increase in wintertime), day time (auto traffic). The received data we consider as first experiments in organization of long time monitoring of cites atmosphere, using new technologies (WSN). This

  19. Tracer tests Wairakei

    International Nuclear Information System (INIS)

    McCabe, W.J.; Manning, M.R.; Barry, B.J.

    1980-07-01

    The report summarises the radioactive tracer tests, using iodine-131 and bromine-82, made in the Wairakei geothermal field over the period 1978-80. Injection of tracer into three wells with strong cool water downflows at about 300-400m below ground level, produced strong rapid responses from the only deep wells feeding from about 800-1000m and lying in the south-westerly direction from the injection wells, i.e. parallel to the fault planes. Shallower wells, even though in some cases much closer to the injection well, reacted much more slowly. Velocities, as measured by peak arrival times, as high as 22m/h over 200m and 11m/h over 650m, were found. The flow patterns for the cool water feeds to the production area are discussed

  20. Radioactive tracers in Sedimentology

    International Nuclear Information System (INIS)

    Rodrigues, H.T.

    1973-01-01

    First is given a broad description of the uses of radioactive tracers in Sedimentology. The general method is established, including determinations of probability and standard deviation. Following are determined: the response law of the detector, the minimum mass for statistical detection, and the minimum mass for dynamic detection. The granularity is an important variable in these calculations. Final conclusions are given, and results are compared with existing theories

  1. Experiences of sexual relationships of young black women in an atmosphere of coercion.

    Science.gov (United States)

    Clüver, Frances; Elkonin, Diane; Young, Charles

    2013-03-01

    Negotiations surrounding sexual activity are characterised by multiple power disparities that include race, social status and age, with gender being the most dominant differential in heterosexual interactions. Research has shown that women are physiologically more at risk of contracting HIV than men, as indicated by the higher infection rates of the former. Many African societies operate via a hegemonic masculinity, with patriarchal governance and female subordination being the norm, placing women at even greater risk of HIV infection. In this qualitative phenomenological study, four black school-going adolescent women living in Grahamstown were interviewed using a semi-structured interview to gather data. An interpretative phenomenological analysis was conducted on the data to provide subjective insights of the experiences of the participants with regard to their interactions with men. From the findings, it became apparent that the participants felt pressured, coerced or manipulated by male counterparts. This pressure and coercion was not just felt in their interactions with older men, but also in their romantic partnerships. Three of the participants experienced pressure to engage in sexual intercourse with their boyfriends when they were unwilling or unready, and they reported being faced with additional pressure to engage in unprotected sex. Furthermore, it became apparent that each participant had an underlying fear of being raped and considered this as a genuine threat to her safety and sexual health. The atmosphere within which these participants negotiate their sexual agency is thus heavily informed by male control, coercion and the threat of violence or rape.

  2. Experiments on HFE-7100 pool boiling at atmospheric pressure in horizontal narrow spaces

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmini, G.; Misale, M.; Priarone, A. [Universita degli Studi di Genova (Italy). DIPTEM - Sezione di Termoenergetica e Condizionamento Ambientale

    2009-07-01

    Experiments were performed to examine the pool boiling heat transfer and critical heat flux on a smooth copper circular surface, confined by a face-to-face parallel unheated surface, by changing the gap between the surfaces and the unheated surface diameter. Pool boiling data at atmospheric pressure were obtained for saturated HFE-7100. The gap values investigated, between the boiling surface and the adiabatic one, were s 0.5, 1.0, 2.0, 3.5 mm. To confine the boiling surface, two different Plexiglas plates were used: the former characterised by a diameter D = 60 mm, large as the overall test section support, the latter characterised by a diameter D = 30 mm, large to cover only copper boiling surface (d = 30 mm). For each configuration, boiling curves were obtained up to the thermal crisis. For both different types of confinement, it was observed that the boiling curves match at low wall superheat, except for s = 0.5 mm, 1 mm. However, at high wall superheat, a drastic reduction in heat transfer as well as CHF appears decreasing the channel width s; for all gap sizes, this reduction is less pronounced for the smaller confinement wall (D = 30 mm). Instead, at low wall superheat for gap of 0.5 and 1.0 mm, the heat transfer coefficient is higher for diameter disc of 60 mm. CHF data were also compared with a literature correlation (Misale and al., 2009). (author)

  3. Journal: Efficient Hydrologic Tracer-Test Design for Tracer ...

    Science.gov (United States)

    Hydrological tracer testing is the most reliable diagnostic technique available for the determination of basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test design can be difficult because of a lack of prior knowledge of the basic hydraulic and geometric parameters desired and the appropriate tracer mass to release. A new efficient hydrologic tracer-test design (EHTD) methodology has been developed to facilitate the design of tracer tests by root determination of the one-dimensional advection-dispersion equation (ADE) using a preset average tracer concentration which provides a theoretical basis for an estimate of necessary tracer mass. The method uses basic measured field parameters (e.g., discharge, distance, cross-sectional area) that are combined in functional relatipnships that descrive solute-transport processes related to flow velocity and time of travel. These initial estimates for time of travel and velocity are then applied to a hypothetical continuous stirred tank reactor (CSTR) as an analog for the hydrological-flow system to develop initial estimates for tracer concentration, tracer mass, and axial dispersion. Application of the predicted tracer mass with the hydraulic and geometric parameters in the ADE allows for an approximation of initial sample-collection time and subsequent sample-collection frequency where a maximum of 65 samples were determined to be necessary for descri

  4. First ever in situ observations of Venus' polar upper atmosphere density using the tracking data of the Venus Express Atmospheric Drag Experiment (VExADE)

    Science.gov (United States)

    Rosenblatt, P.; Bruinsma, S. L.; Müller-Wodarg, I. C. F.; Häusler, B.; Svedhem, H.; Marty, J. C.

    2012-02-01

    On its highly elliptical 24 h orbit around Venus, the Venus Express (VEX) spacecraft briefly reaches a periapsis altitude of nominally 250 km. Recently, however, dedicated and intense radio tracking campaigns have taken place in August 2008, October 2009, February and April 2010, for which the periapsis altitude was lowered to the 186-176 km altitude range in order to be able to probe the upper atmosphere of Venus above the North Pole for the first time ever in situ. As the spacecraft experiences atmospheric drag, its trajectory is measurably perturbed during the periapsis pass, allowing us to infer total atmospheric mass density at the periapsis altitude. A Precise Orbit Determination (POD) of the VEX motion is performed through an iterative least-squares fitting process to the Doppler tracking data, acquired by the VEX radioscience experiment (VeRa). The drag acceleration is modelled using an initial atmospheric density model (VTS3 model, Hedin, A.E., Niemann, H.B., Kasprzak, W.T., Seiff, A. [1983]. J. Geophys. Res. 88, 73-83). A scale factor of the drag acceleration is estimated for each periapsis pass, which scales Hedin's density model in order to best fit the radio tracking data. Reliable density scale factors have been obtained for 10 passes mainly from the second (October 2009) and third (April 2010) VExADE campaigns, which indicate a lower density by a factor of about 1.8 than Hedin's model predicts. These first ever in situ polar density measurements at solar minimum have allowed us to construct a diffusive equilibrium density model for Venus' thermosphere, constrained in the lower thermosphere primarily by SPICAV-SOIR measurements and above 175 km by the VExADE drag measurements (Müller-Wodarg et al., in preparation). The preliminary results of the VExADE campaigns show that it is possible to obtain with the POD technique reliable estimates of Venus' upper atmosphere densities at an altitude of around 175 km. Future VExADE campaigns will benefit from

  5. Tracers and Tracer Testing: Design, Implementation, Tracer Selection, and Interpretation Methods

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Shook; Shannon L.; Allan Wylie

    2004-01-01

    Conducting a successful tracer test requires adhering to a set of steps. The steps include identifying appropriate and achievable test goals, identifying tracers with the appropriate properties, and implementing the test as designed. When these steps are taken correctly, a host of tracer test analysis methods are available to the practitioner. This report discusses the individual steps required for a successful tracer test and presents methods for analysis. The report is an overview of tracer technology; the Suggested Reading section offers references to the specifics of test design and interpretation.

  6. CalWater 2 - Precipitation, Aerosols, and Pacific Atmospheric Rivers Experiment

    Science.gov (United States)

    Spackman, Ryan; Ralph, Marty; Prather, Kim; Cayan, Dan; DeMott, Paul; Dettinger, Mike; Fairall, Chris; Leung, Ruby; Rosenfeld, Daniel; Rutledge, Steven; Waliser, Duane; White, Allen

    2014-05-01

    Emerging research has identified two phenomena that play key roles in the variability of the water supply and the incidence of extreme precipitation events along the West Coast of the United States. These phenomena include the role of (1) atmospheric rivers (ARs) in delivering much of the precipitation associated with major storms along the U.S. West Coast, and (2) aerosols—from local sources as well as those transported from remote continents—and their modulating effects on western U.S. precipitation. A better understanding of these processes is needed to reduce uncertainties in weather predictions and climate projections of extreme precipitation and its effects, including the provision of beneficial water supply. This presentation summarizes science gaps associated with (1) the evolution and structure of ARs including cloud and precipitation processes and air-sea interaction, and (2) aerosol interaction with ARs and the impact on precipitation, including locally-generated aerosol effects on orographic precipitation along the U.S. West Coast. Observations are proposed for multiple winter seasons as part of a 5-year broad interagency vision referred to as CalWater 2 to address these science gaps (http://esrl.noaa.gov/psd/calwater). In the near term, a science investigation is being planned including a targeted set of aircraft and ship-based measurements and associated evaluation of data in near-shore regions of California and in the eastern Pacific for an intensive observing period between January 2015 and March 2015. DOE's Atmospheric Radiation Measurement (ARM) program and NOAA are coordinating on deployment of airborne and ship-borne facilities for this period in a DOE-sponsored study called ACAPEX (ARM Cloud Aerosol and Precipitation Experiment) to complement CalWater 2. The motivation for this major study is based on findings that have emerged in the last few years from airborne and ground-based studies including CalWater and NOAA's HydroMeterology Testbed

  7. Laboratory Experiments and Instrument Development for the Study of Atmospheric Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Davidovits, Paul

    2011-12-10

    Soot particles are generated by incomplete combustion of fossil and biomass fuels. Through direct effects clear air aerosols containing black carbon (BC) such as soot aerosols, absorb incoming light heating the atmosphere, while most other aerosols scatter light and produce cooling. Even though BC represents only 1-2% of the total annual emissions of particulate mass to the atmosphere, it has been estimated that the direct radiative effect of BC is the second-most important contributor to global warming after absorption by CO2. Ongoing studies continue to underscore the climate forcing importance of black carbon. However, estimates of the radiative effects of black carbon on climate remain highly uncertain due to the complexity of particles containing black carbon. Quantitative measurement of BC is challenging because BC often occurs in highly non-spherical soot particles of complex morphology. Freshly emitted soot particles are typically fractal hydrophobic aggregates. The aggregates consist of black carbon spherules with diameters typically in the range of about 15-40 nm, and they are usually coated by adsorbed polyaromatic hydrocarbons (PAHs) produced during combustion. Diesel-generated soot particles are often emitted with an organic coating composed primarily of lubricating oil and unburned fuel, as well as well as PAH compounds. Sulfuric acid has also been detected in diesel and aircraft-emitted soot particles. In the course of aging, these particle coatings may be substantially altered by chemical reactions and/or the deposition of other materials. Such processes transform the optical and CCN properties of the soot aerosols in ways that are not yet well understood. Our work over the past seven years consisted of laboratory research, instrument development and characterization, and field studies with the central focus of improving our understanding of the black carbon aerosol climate impacts. During the sixth year as well as during this seventh year (no

  8. Data processing technique for multiangle lidar sounding of poorly stratified polluted atmospheres: Theory and experiment

    Science.gov (United States)

    Cyle E. Wold; Vladimir A. Kovalev; Alexander P. Petkov; Wei Min Hao

    2012-01-01

    Scanning elastic lidar, which can operate in different slant directions, is the most appropriate remote sensing tool for investigating the optical properties of smoke-polluted atmospheres. However, the commonly used methodologies of multiangle measurements are based on the assumption of horizontal stratification of the searched atmosphere1,2. When working in real...

  9. The Passy-2015 field experiment: wintertime atmospheric dynamics and air quality in a narrow alpine valley

    Science.gov (United States)

    Paci, Alexandre; Staquet, Chantal

    2016-04-01

    Wintertime anticyclonic conditions lead to the formation of persistent stable boundary layers which may induce severe air pollution episodes in urban or industrialized area, particularly in mountain regions. The Arve river valley in the Northern Alps is very sensitive to this phenomenon, in particular close to the city of Passy (Haute-Savoie), 20 km down valley past Chamonix. This place is indeed one of the worst place in France regarding air quality, the concentration of fine particles and Benzo(a)pyrene (a carcinogenic organic compound) regularly exceeding the EU legal admissible level during winter. Besides air quality measurements, such as the ones presently carried in the area by the local air quality agency Air Rhône-Alpes or in the DECOMBIO project led by LGGE, it is crucial to improve our knowledge of the atmospheric boundary layer dynamics and processes at the valley scale under these persistent stable conditions in order to improve our understanding on how it drives pollutant dispersion. These issues motivated the Passy-2015 field experiment which took place during the winter 2014-2015. A relatively large set-up of instruments was deployed on a main measurement site in the valley center and on four other satellite sites. It includes several remote sensing instruments, a surface flux station, a 10 m instrumented tower, a large aperture scintillometer, a fog monitoring station among others. Most of the instruments were present from early January to the end of February. During two intensive observation periods, 6-14 February and 17-20 February, the instrumental set-up was completed on the main site with high frequency radio-soundings (up to one per 1h30), a tethered balloon, a remote controlled drone quadcopter and a sodar. The field campaign, the instruments, the meteorological situations observed and preliminary results will be presented. This field experiment is part of the Passy project funded by ADEME through the French national programme LEFE/INSU and

  10. Physical analysis of multivariate measurements in the Atmospheric high-energy physics experiments within ADEI platform

    International Nuclear Information System (INIS)

    Avakyan, K.; Chilingarian, A.; Karapetyan, T.; Chilingaryan, S.

    2017-01-01

    To make transformational scientific progress in Space science and geophysics, the Sun, heliosphere, magnetosphere and different layers of the atmosphere must be studied as a coupled system. Presented paper describes how information on complicated physical processes on Sun, in the heliosphere, magnetosphere and atmosphere can be made immediately assessable for researchers via advanced multivariate visualization system with simple statistical analysis package. Research of the high-energy phenomena in the atmosphere and the atmospheric discharges is of special importance. The relationship between thundercloud electrification, lightning activity, wideband radio emission and particle fluxes have not been yet unambiguously established. One of most intriguing opportunities opening by observation of the high-energy processes in the atmosphere is their relation to lightning initiation. Investigations of the accelerated structures in the geospace plasmas can as well shed light on particle acceleration up to much higher energies in the similar structures of space plasmas in the distant objects of the Universe. (author)

  11. Site-Specific Atmospheric Dispersion Characteristics of Korean Nuclear Power Plant Sites

    International Nuclear Information System (INIS)

    Han, M. H.; Kim, E. H.; Suh, K. S.; Hwang, W. T.; Choi, Y. G.

    2001-01-01

    Site-specific atmospheric dispersion characteristics have been analyzed. The northwest and the southwest wind prevail on nuclear sites of Korea. The annual isobaric surface averaged for twenty years around Korean peninsula shows that west wind prevails. The prevailing west wind is profitable in the viewpoint of radiation protection because three of four nuclear sites are located in the east side. Large scale field tracer experiments over nuclear sites have been conducted for the purpose of analyzing the atmospheric dispersion characteristics and validating a real-time atmospheric dispersion and dose assessment system FADAS. To analyze the site-specific atmospheric dispersion characteristics is essential for making effective countermeasures against a nuclear emergency

  12. Use of radioactive tracers in dynamic sedimentology

    International Nuclear Information System (INIS)

    Tola, Francois.

    1982-01-01

    In the first part, developments in the use of radioactive tracers in sedimentology are recalled together with the corresponding fields of application and the identities of the main users. The state-of-the-art in France is also discussed; The main characteristics of the method are then described and compared with those of more classical methods. The results that can be obtained with tracer methods are then outlined. The criteria employed to establish the granulometry characteristics of the tracer, the particular radioisotope to be used, and the masses and activities involved, are treated. A list is then given of the main isotopes available in France and their characteristics. The various different labelling techniques employed are studied together with their respective advantages and disadvantages. The special case of pelitic sediments is mentioned. The use of reduced model isotope generators, double labelling and applications to studies of the mud plug in the Gironde Estuary are also discussed. The methods and materials used for injecting and detecting tracers are described, emphasis being given to the economic factors associated with the use of radioactive tracers in sedimentology. The second part of the report contains two chapters: - studies of transport by driftage: presentation and analysis of results and the application of the Count Rate Balance method to obtain quantitative information on transport; - studies of in-suspension transport of fine sediments in the sea: the procedures adopted from the moment when the tracer is introduced up to the time when the results are analyzed and interpreted, enables the trajectories and mean velocities of the transported sediments to be determined together with their degree of dilution and their settling speeds and rates; it is also possible to investigate the evolution and horizontal dispersion of the sediments in this way. Results from recent experiments are presented in both parts of the report

  13. Hydraulic characterisation of karst systems with man-made tracers

    International Nuclear Information System (INIS)

    Werner, A.

    1998-01-01

    Tracer experiments using man-made tracers are common in hydrogeological exploration of groundwater aquifers in karst systems. In the present investigation, a convection-dispersion model (multidispersion model with consideration of several flow paths) and a single-cleft model (consideration of the diffusion between the cleft and the surrounding rock matrix) were used for evaluating tracer experiments in the main hydrological system of the saturated zone of karst systems. In addition to these extended analytical solutions, a numerical transport model was developed for investigating the influence of the transient flow rate on the flow and transport parameters. Comparative evaluations of the model approaches for the evaluation of tracer experiments were made in four different karst systems: Danube-Aach, Paderborn, Slowenia and Lurbach, of which the Danube-Aach system was considered as the most important. The investigation also comprised three supplementary experiments in order to enable a complete hydraulic characterisation of the system. (orig./SR) [de

  14. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  15. Guidebook on radioisotope tracers in industry

    International Nuclear Information System (INIS)

    1990-01-01

    The idea of using tracers (chemical, dyes, etc.) in the investigation of complex physical phenomena has always attracted the attention of scientists and engineers. When radioactive isotopes became available it was immediately recognized that they offered an almost ideal solution to tracer selection. This book is devoted to reviewing the present status of the tracer method as such and to its applications to those branches of industry which have derived large benefits from the use of this modern technology. The main objectives of the IAEA's Industrial Applications and Chemistry Section is to help Member States in introducing to their own industries the different isotope and radiation techniques which have become available as a result of developments in the nuclear sciences. This section proposed the preparation of this guidebook, putting together various radiotracer methods and the experience obtained so far in their industrial use. Chapters 2 to 4 cover the general concept of tracers, technology and safety aspects, as well as data evaluation and interpretation. In chapter 5, therefore, general applications are discussed. In chapter 6, specialists in selected fields discuss their experience in radiotracer applications in various types of industrial activity. Most case studies are illustrated by at least one detailed example of an experiment carried out at an industrial installation. Current trends in the development of radiotracer methods are discussed in chapter 7, from both a theoretical and a practical viewpoint. Some possible new RTT applications in the future are also discussed here. Sealed radioactive sources are used almost as often as radioisotope tracers in industrial measurements. Annex I gives a short review of these techniques. Readers who are interested in the basic principles of radioisotope production will find the necessary information in Annex II. Annexes III, V and VI provide a demonstration of fundamental relations and properties; useful

  16. Validation of NO2 and NO from the Atmospheric Chemistry Experiment (ACE

    Directory of Open Access Journals (Sweden)

    M. Schneider

    2008-10-01

    Full Text Available Vertical profiles of NO2 and NO have been obtained from solar occultation measurements by the Atmospheric Chemistry Experiment (ACE, using an infrared Fourier Transform Spectrometer (ACE-FTS and (for NO2 an ultraviolet-visible-near-infrared spectrometer, MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation. In this paper, the quality of the ACE-FTS version 2.2 NO2 and NO and the MAESTRO version 1.2 NO2 data are assessed using other solar occultation measurements (HALOE, SAGE II, SAGE III, POAM III, SCIAMACHY, stellar occultation measurements (GOMOS, limb measurements (MIPAS, OSIRIS, nadir measurements (SCIAMACHY, balloon-borne measurements (SPIRALE, SAOZ and ground-based measurements (UV-VIS, FTIR. Time differences between the comparison measurements were reduced using either a tight coincidence criterion, or where possible, chemical box models. ACE-FTS NO2 and NO and the MAESTRO NO2 are generally consistent with the correlative data. The ACE-FTS and MAESTRO NO2 volume mixing ratio (VMR profiles agree with the profiles from other satellite data sets to within about 20% between 25 and 40 km, with the exception of MIPAS ESA (for ACE-FTS and SAGE II (for ACE-FTS (sunrise and MAESTRO and suggest a negative bias between 23 and 40 km of about 10%. MAESTRO reports larger VMR values than the ACE-FTS. In comparisons with HALOE, ACE-FTS NO VMRs typically (on average agree to ±8% from 22 to 64 km and to +10% from 93 to 105 km, with maxima of 21% and 36%, respectively. Partial column comparisons for NO2 show that there is quite good agreement between the ACE instruments and the FTIRs, with a mean difference of +7.3% for ACE-FTS and +12.8% for MAESTRO.

  17. Transuranic and tracer simulant resuspension

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1977-07-01

    Plutonium resuspension results are summarized for experiments conducted at Rocky Flats, onsite on the Hanford reservation, and for winds blowing from offsite onto the Hanford reservation near the Prosser barricade boundary. In each case, plutonium resuspension was shown by increased airborne plutonium concentrations as a function of either wind speed or as compared to fallout levels. All measured airborne concentrations were below maximum permissible concentrations (MPC). Both plutonium and cesium concentrations on airborne soil were normalized by the quantity of airborne soil sampled. Airborne radionuclide concentrations in μCi/g were related to published values for radionuclide concentrations on surface soils. For this ratio of radionuclide concentration per gram on airborne soil divided by that for ground surface soil, there are eight orders of magnitude uncertainty from 10 -4 to 10 4 . Horizontal plutonium fluxes on airborne nonrespirable soils at all three sites were bracketed within the same three to four orders of magnitude from 10 -7 to 10 -3 μCi/(m 2 day) for plutonium-239 and 10 -8 to 10 -5 μCi/(m 2 day) for plutonium-238. These are the entire experimental base for nonrespirable airborne plutonium transport. Airborne respirable plutonium-239 concentrations increased with wind speed for a southeast wind direction coming from offsite near the Hanford reservation Prosser barricade. Airborne plutonium fluxes on nonrespirable particles had isotopic ratios, 240 Pu/ 239+240 Pu, similar to weapons grade plutonium rather than fallout plutonium. Resuspension rates were summarized for controlled inert particle tracer simulant experiments. Wind resuspension rates for tracers increased with wind speed to about the fifth power

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

    International Nuclear Information System (INIS)

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

    1974-09-01

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

  19. Methods of 15N tracer research in biological systems

    International Nuclear Information System (INIS)

    Hirschberg, K.; Faust, H.

    1985-01-01

    The application of the stable isotope 15 N is of increasing importance in different scientific disciplines, especially in medicine, agriculture, and the biosciences. The close correlation between the growing interest and improvements of analytical procedures resulted in remarkable advances in the 15 N tracer technique. On the basis of the latest results of 15 N tracer research in life sciences and agriculture methods of 15 N tracer research in biological systems are compiled. The 15 N methodology is considered under three headings: Chemical analysis with a description of methods of sample preparation (including different separation and isolation methods for N-containing substances of biological and agricultural origin) and special procedures converting ammonia to molecular nitrogen. Isotopic analysis with a review on the most important methods of isotopic analysis of nitrogen: mass spectrometry (including the GC-MS technique), emission spectrometry, NMR spectroscopy, and other analytical procedures. 15 N-tracer techniques with a consideration of the role of the isotope dilution analysis as well as different labelling techniques and the mathematical interpretation of tracer data (modelling, N turnover experiments). In these chapters also sources of errors in chemical and isotopic analysis, the accuracy of the different methods and its importance on tracer experiments are discussed. Procedures for micro scale 15 N analysis and aspects of 15 N analysis on the level of natural abundance are considered. Furthermore some remarks on isotope effects in 15 N tracer experiments are made. (author)

  20. Results from a Set of Three-Dimensional Numerical Experiments of a Hot Jupiter Atmosphere

    Science.gov (United States)

    Mayne, Nathan J.; Debras, Flirian; Baraffe, Isabelle; Thuburn, John; Amundsen, David S.; Acreman, David M.; Smith, Chris; Browning, Matthew K.; Manners, James; Wood Nigel

    2017-01-01

    We present highlights from a large set of simulations of a hot Jupiter atmosphere, nominally based on HD 209458b, aimed at exploring both the evolution of the deep atmosphere, and the acceleration of the zonal flow or jet. We find the occurrence of a super-rotating equatorial jet is robust to changes in various parameters, and over long timescales, even in the absence of strong inner or bottom boundary drag. This jet is diminished in one simulation only, where we strongly force the deep atmosphere equator-to-pole temperature gradient over long timescales. Finally, although the eddy momentum fluxes in our atmosphere show similarities with the proposed mechanism for accelerating jets on tidally-locked planets, the picture appears more complex. We present tentative evidence for a jet driven by a combination of eddy momentum transport and mean flow.

  1. A discussion on the determination of atmospheric OH and its trends

    Directory of Open Access Journals (Sweden)

    P. Jöckel

    2003-01-01

    Full Text Available The oxidation efficiency of the troposphere is largely determined by the hydroxyl radical and its global distribution. Its presence limits the lifetime of most trace gases. Because of the great importance of several of these gases for climate, ozone budget and OH itself, it is of fundamental importance to acquire knowledge about atmospheric OH and possible trends in its concentrations. In the past, average concentrations of OH and trends were largely derived using industrially produced CH3CCl3 as a chemical tracer. The analyses have given valuable, but also rather uncertain results. In this paper we describe an idealized computer aided tracer experiment which has as one of its goals to derive tracer concentration weighted, global average k(OH>, where the temporal and spatial OH distribution is prescribed and k is the reaction rate coefficient of OH with a hitherto never produced (Gedanken tracer, which is injected at a number of surface sites in the atmosphere in well known amounts over a given time period. Using a three-dimensional (3-D time-dependent chemistry transport model, k(OH> can be accurately determined from the calculated 3-D tracer distribution. It is next explored how well k(OH> can be retrieved solely from tracer measurements at a limited number of surface sites. The results from this analysis are encouraging enough to actually think about the feasibility to carry out a global dedicated tracer experiment to derive k(OH> and its temporal trends. However, before that, we propose to test the methods that are used to derive k(OH>, so far largely using CH3CCl3, with an idealized tracer experiment, in which a global chemistry transport model is used to calculate the ``Gedanken'' tracer distribution, representing the real 3-D world, from which k(OH> is derived, using only the tracer information from a limited set of surface sites. We propose here that research groups which are, or will be, involved in global average OH studies to

  2. Influence of stability classification on atmospheric diffusion calculations for elevated releases over a terrain of major roughness

    International Nuclear Information System (INIS)

    Hu Erbang

    1988-01-01

    A series (22) of atmospheric tracer experiments with 100m release height have been performed at the kernforschungszentrum karlsruhe (KfK) of West Germany over a terrain of major roughness (Z 0 = 1.5 m). The concentration data of the tracers are statistically analysed in which 5 methods of stability classification are used. The results show that the normalized diffusion factors predicted by Gaussian plume dispersion model is in good agreement with the observed ones for elevated releases over a terrain of major roughness. Differnent sets of dispersion parameters could be obtained for the same series of atmospheric tracer experiments if different methods of classification are applied. The same method of stability classification should be used for the application of these dispersion parameters to evaluate the environment impact

  3. Simulation of tracer dispersion from elevated and surface releases in complex terrain

    Science.gov (United States)

    Hernández, J. F.; Cremades, L.; Baldasano, J. M.

    A new version of an advanced mesoscale dispersion modeling system for simulating passive air pollutant dispersion in the real atmospheric planetary boundary layer (PBL), is presented. The system comprises a diagnostic mass-consistent meteorological model and a Lagrangian particle dispersion model (LADISMO). The former version of LADISMO, developed according to Zannetti (Air pollution modelling, 1990), was based on the Monte Carlo technique and included calculation of higher-order moments of vertical random forcing for convective conditions. Its ability to simulate complex flow dispersion has been stated in a previous paper (Hernández et al. 1995, Atmospheric Environment, 29A, 1331-1341). The new version follows Thomson's scheme (1984, Q. Jl Roy. Met. Soc.110, 1107-1120). It is also based on Langevin equation and follows the ideas given by Brusasca et al. (1992, Atmospheric Environment26A, 707-723) and Anfossi et al. (1992, Nuovo Cemento 15c, 139-158). The model is used to simulate the dispersion and predict the ground level concentration (g.l.c.) of a tracer (SF 6) released from both an elevated source ( case a) and a ground level source ( case b) in a highly complex mountainous terrain during neutral and synoptically dominated conditions ( case a) and light and apparently stable conditions ( case b). The last case is considered as being a specially difficult task to simulate. In fact, few works have reported situations with valley drainage flows in complex terrains and real stable atmospheric conditions with weak winds. The model assumes that nearly calm situations associated to strong stability and air stagnation, make the lowest layers of PBL poorly diffusive (Brusasca et al., 1992, Atmospheric Environment26A, 707-723). Model results are verified against experimental data from Guardo-90 tracer experiments, an intensive field campaign conducted in the Carrion river valley (Northern Spain) to study atmospheric diffusion within a steep walled valley in mountainous

  4. Radionuclides as tracers

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Importance of radioisotopes in medicine is because of their two characteristics: their biological behaviour is identical to their stable counterparts, and because they are radioactive their emissions can be detected by a suitable instrument. All isotopes of iodine will behave in the same way and will concentrate in the thyroid gland. There is no way of detecting the stable, natural iodine in the thyroid gland, but the presence of radioactive iodine can be detected externally in vivo by a detector. Thus, the radioactive iodine becomes a tracer, a sport of a spy, which mimics the behaviour of natural iodine and relays information to a detector. The radioactive tracers are popular because of the ease with which they can be detected in vivo and the fact that the measurement of their presence in the body can be in quantitative terms. The measurement can be very accurate and sensitive. Whenever the measurements can be done in vivo, the information is obtained in dynamic terms, as it is happening, as if the physiological events become transparent

  5. How well do different tracers constrain the firn diffusivity profile?

    Directory of Open Access Journals (Sweden)

    C. M. Trudinger

    2013-02-01

    Full Text Available Firn air transport models are used to interpret measurements of the composition of air in firn and bubbles trapped in ice in order to reconstruct past atmospheric composition. The diffusivity profile in the firn is usually calibrated by comparing modelled and measured concentrations for tracers with known atmospheric history. However, in most cases this is an under-determined inverse problem, often with multiple solutions giving an adequate fit to the data (this is known as equifinality. Here we describe a method to estimate the firn diffusivity profile that allows multiple solutions to be identified, in order to quantify the uncertainty in diffusivity due to equifinality. We then look at how well different combinations of tracers constrain the firn diffusivity profile. Tracers with rapid atmospheric variations like CH3CCl3, HFCs and 14CO2 are most useful for constraining molecular diffusivity, while &delta:15N2 is useful for constraining parameters related to convective mixing near the surface. When errors in the observations are small and Gaussian, three carefully selected tracers are able to constrain the molecular diffusivity profile well with minimal equifinality. However, with realistic data errors or additional processes to constrain, there is benefit to including as many tracers as possible to reduce the uncertainties. We calculate CO2 age distributions and their spectral widths with uncertainties for five firn sites (NEEM, DE08-2, DSSW20K, South Pole 1995 and South Pole 2001 with quite different characteristics and tracers available for calibration. We recommend moving away from the use of a firn model with one calibrated parameter set to infer atmospheric histories, and instead suggest using multiple parameter sets, preferably with multiple representations of uncertain processes, to assist in quantification of the uncertainties.

  6. Nanoparticle tracers in calcium carbonate porous media

    KAUST Repository

    Li, Yan Vivian

    2014-07-15

    Tracers are perhaps the most direct way of diagnosing subsurface fluid flow pathways for ground water decontamination and for natural gas and oil production. Nanoparticle tracers could be particularly effective because they do not diffuse away from the fractures or channels where flow occurs and thus take much less time to travel between two points. In combination with a chemical tracer they can measure the degree of flow concentration. A prerequisite for tracer applications is that the particles are not retained in the porous media as the result of aggregation or sticking to mineral surfaces. By screening eight nanoparticles (3-100 nm in diameter) for retention when passed through calcium carbonate packed laboratory columns in artificial oil field brine solutions of variable ionic strength we show that the nanoparticles with the least retention are 3 nm in diameter, nearly uncharged, and decorated with highly hydrophilic polymeric ligands. The details of these column experiments and the tri-modal distribution of zeta potential of the calcite sand particles in the brine used in our tests suggests that parts of the calcite surface have positive zeta potential and the retention of negatively charged nanoparticles occurs at these sites. Only neutral nanoparticles are immune to at least some retention. © 2014 Springer Science+Business Media.

  7. Using neural networks to describe tracer correlations

    Directory of Open Access Journals (Sweden)

    D. J. Lary

    2004-01-01

    Full Text Available Neural networks are ideally suited to describe the spatial and temporal dependence of tracer-tracer correlations. The neural network performs well even in regions where the correlations are less compact and normally a family of correlation curves would be required. For example, the CH4-N2O correlation can be well described using a neural network trained with the latitude, pressure, time of year, and methane volume mixing ratio (v.m.r.. In this study a neural network using Quickprop learning and one hidden layer with eight nodes was able to reproduce the CH4-N2O correlation with a correlation coefficient between simulated and training values of 0.9995. Such an accurate representation of tracer-tracer correlations allows more use to be made of long-term datasets to constrain chemical models. Such as the dataset from the Halogen Occultation Experiment (HALOE which has continuously observed CH4  (but not N2O from 1991 till the present. The neural network Fortran code used is available for download.

  8. Using radioactive tracer technique in municipal hygiene

    International Nuclear Information System (INIS)

    Yurasova, O.I.

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology

  9. Using radioactive tracer technique in municipal hygiene

    Energy Technology Data Exchange (ETDEWEB)

    Yurasova, O I [Institut Obshchej i Kommunal' noj Gigieny, Moscow (USSR)

    1974-01-01

    Work of the A. N. Syrsin Institute of General and Municiapl Hygiene using raidoactive tracers is reviewed. The studies include research on protein metabolism in the living organism following action of unfavorable factors of the environment; determination of the paths of introduction into the organism of substances with an alien composition; and study of the rate of resorption of subcutaneous papuli. Results are shown of radioactive-tracer studies on the mechanism of action of poisonous substances on the living organism and of migration of alien chemical compounds in the organism and in objects in the environment. It is concluded that the radioactive tracer method has wide application in municipal hygiene and sanitary microbiology. The absence of laborious operations, economy of time, precision of the experiments, and the possibility of obtaining additional information on the mechanism of action of poisonous substances on the organism and the low cost of such studies compared with other methods makes the radioactive tracer method economically attractive. The studies made show the various types of use of the method in municipal hygiene and sanitary microbiology.

  10. Atmosphere dependence of fission products release: The Vercors 4 and 5 experiments

    Energy Technology Data Exchange (ETDEWEB)

    Andre, B.; Ducros, G.; Tourasse, M.; Ferroud-Plattet, M.P. [CEA Centre d`Etudes de Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique; Boulaud, D. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    Because of the severe consequences, in terms of radiological and biological effects, of a nuclear accident, the international reactor safety authorities initiated, 25 years ago, numerous experimental programs in order to improve the understanding and the prediction of these situations. In France, the Nuclear Protection and Safety Institute (IPSN) in collaboration with Electricite de France (EDF) co-fund the Heva-Vercors program, since 1983. The experiments are conducted in a shielded hot cell of the LAMA facility at Grenoble. The test specimen is a fuel rod section taken from a power reactor operated by EDF and includes three irradiated pellets in their original cladding. The fuel sample is re-irradiated at low power in the Siloe experimental reactor for seven days in order to recreate the short-lived fission products without inducing any in-pile release. Since the experimental sequence is performed less than 40 hours after the end of the reirradiation, direct measurement of radioactive fission products release is possible using gamma spectrometry. The measurements performed during the tests are essentially aimed at characterising the release kinetics and the total release of fission products and structural materials as a function of fuel temperature and oxidising/reducing conditions of the environment. The four last tests (Vercors 3 to Vercors 6), performed at 2600 K, allowed to measure the kinetic of high and low volatile species release, as well as the total released fraction of non volatile species and the transuranic elements. This paper is devoted to the comparison of the Vercors 4 and Vercors 5 tests. The first one has been conducted up to 2600 K under reducing conditions (hydrogen fluid), after an oxidising period at 1670 K. The second one was performed in a pure steam atmosphere after several plateaus at intermediate temperatures in oxidising conditions. The total release of volatile (Sb, Te, I, Cs) is not significantly modified and a higher release of Mo

  11. Validation Study for an Atmospheric Dispersion Model, Using Effective Source Heights Determined from Wind Tunnel Experiments in Nuclear Safety Analysis

    Directory of Open Access Journals (Sweden)

    Masamichi Oura

    2018-03-01

    Full Text Available For more than fifty years, atmospheric dispersion predictions based on the joint use of a Gaussian plume model and wind tunnel experiments have been applied in both Japan and the U.K. for the evaluation of public radiation exposure in nuclear safety analysis. The effective source height used in the Gaussian model is determined from ground-level concentration data obtained by a wind tunnel experiment using a scaled terrain and site model. In the present paper, the concentrations calculated by this method are compared with data observed over complex terrain in the field, under a number of meteorological conditions. Good agreement was confirmed in near-neutral and unstable stabilities. However, it was found to be necessary to reduce the effective source height by 50% in order to achieve a conservative estimation of the field observations in a stable atmosphere.

  12. Radio occultation studies of the Venus atmosphere with the Magellan spacecraft. 2: Results from the October 1991 experiments

    Science.gov (United States)

    Jenkins, Jon M.; Steffes, Paul G.; Hinson, David P.; Twicken, Joseph D.; Tyler, G. Leonard

    1994-01-01

    On October 5 and 6, 1991, three dual-frequency ingress radio occultation experiments were conducted at Venus during consecutive orbits of the Magellan spacecraft. The radio signals probed a region of the atmosphere near 65 deg N, with a solar zenith angle of 108 deg, reaching below 35 km at 3.6 cm, and below 34 km at 13 cm (above a mean radius of 6052 km). The high effective isotropic radiated power (EIRP) of the Magellan spacecraft and highly successful attitude maneuvers allowed these signals to probe deeper than any previous radio occultation experiment and also resulted in the most accurate thermal and sulfuric acid vapor abundance profiles ever obtained at Venus through radio occultation techniques. The performance of the spacecraft and the experiment design are discussed in an accompanying paper. Average electron density profiles retrieved from the data possess peaks between 2600 and 6000/cu cm, well below typical values of 10,000/cu cm retrieved in 1979 by Pioneer Venus at similar solar zenith angles. Other basic results include vertical profiles of temperature, pressure, and density in the neutral atmosphere, 13- and 3.6-cm absorpttivity, and H2SO4 (g) abundance below the main cloud layer. H2SO4 (g) becomes significant below 50 km, reaching peaks between 18 and 24 ppm near 39 km before dropping precipitously below 38 km. These sharp decreases confirm the thermal decomposition of sulfuric acid vapor below 39 km. Since the Venus atmosphere rotated approximately 10 deg between experiments, the data contain information about the horizontal variability of the atmosphere. All derived profiles exhibit significant variations from orbit to orbit, indicating the presence of dynamical processes between 33 and 200 km. In particular, the orbit-to-orbit variations in temperature and in H2SO4 (g) abundance appear to be correlated, suggesting that a common mechanism may be responsible for the observed spatial variations.

  13. Atmospheric proton and deuterium energy spectra determination with the MASS2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Grimani, C.; Brunetti, M.T.; Codino, A.; Finetti, N. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    The energy spectra of atmospheric-secondary protons and deuterium nuclei have been measured during the September 23, 1991, balloon flight of the NMSU/Wizard - MASS2 instrument. The apparatus was launched from Fort Sumner, New Mexico. The geomagnetic cutoff at the launch site is about 4.5 GV/c. The instrument was flown for 9.8 hours at an altitude of over 100,000 feet. Particles detected below the geomagnetic cutoff have been produced mainly by the interactions of the primary cosmic rays with the atmosphere. The measurement of cosmic ray energy spectra below the geomagnetic cutoff provide direct insights into the particle production mechanism and allows comparison to atmospheric cascade calculations.

  14. Shuttle high resolution accelerometer package experiment results - Atmospheric density measurements between 60-160 km

    Science.gov (United States)

    Blanchard, R. C.; Hinson, E. W.; Nicholson, J. Y.

    1988-01-01

    Indirect or inferred values of atmospheric density encountered by the Shuttle Orbiter during reentry have been calculated from acceleration measurements made by the High Resolution Accelerometer Package (HiRAP) and the Orbiter Inertial Measurement Unit (IMU) liner accelerometers. The atmospheric density data developed from this study represent a significant gain with respect to the body of data collected to date by various techniques in the altitude range of 60 to 160 km. The data are unique in that they cover a very wide horizontal range during each flight and provide insight into the actual density variations encountered along the reentry flight path. The data, which were collected over about 3 years, are also characterized by variations in solar activity, geomagnetic index, and local solar time. Comparison of the flight-derived densities with various atmospheric models have been made, and analyses have attempted to characterize the data and to show correlation with selected physical variables.

  15. Infrasound Predictions Using the Weather Research and Forecasting Model: Atmospheric Green's Functions for the Source Physics Experiments 1-6.

    Energy Technology Data Exchange (ETDEWEB)

    Poppeliers, Christian; Aur, Katherine Anderson; Preston, Leiph

    2018-03-01

    This report shows the results of constructing predictive atmospheric models for the Source Physics Experiments 1-6. Historic atmospheric data are combined with topography to construct an atmo- spheric model that corresponds to the predicted (or actual) time of a given SPE event. The models are ultimately used to construct atmospheric Green's functions to be used for subsequent analysis. We present three atmospheric models for each SPE event: an average model based on ten one- hour snap shots of the atmosphere and two extrema models corresponding to the warmest, coolest, windiest, etc. atmospheric snap shots. The atmospheric snap shots consist of wind, temperature, and pressure profiles of the atmosphere for a one-hour time window centered at the time of the predicted SPE event, as well as nine additional snap shots for each of the nine preceding years, centered at the time and day of the SPE event.

  16. A user-orientated approach to provenance capture and representation for in silico experiments, explored within the atmospheric chemistry community.

    Science.gov (United States)

    Martin, Chris J; Haji, Mohammed H; Jimack, Peter K; Pilling, Michael J; Dew, Peter M

    2009-07-13

    We present a novel user-orientated approach to provenance capture and representation for in silico experiments, contrasted against the more systems-orientated approaches that have been typical within the e-Science domain. In our approach, we seek to capture the scientist's reasoning in the form of annotations as an experiment evolves, while using the scientist's terminology in the representation of process provenance. Our user-orientated approach is applied in a case study within the atmospheric chemistry domain: we consider the design, development and evaluation of an electronic laboratory notebook, a provenance capture and storage tool, for iterative model development.

  17. Radon as geological tracer

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, T.; Anjos, R.M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Valladares, D.L.; Rizzotto, M.; Velasco, H.; Ayub, J. Juri [Universidad Nacional de San Luis (Argentina). Inst. de Matematica Aplicada San Luis (IMASL); Silva, A.A.R. da; Yoshimura, E.M. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: This work presents measurements of {sup 222}Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of {sup 40}K, {sup 232}Th and {sup 23}'8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using {sup 222}Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m{sup -3} recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  18. Radon as geological tracer

    International Nuclear Information System (INIS)

    Lacerda, T.; Anjos, R.M.; Silva, A.A.R. da; Yoshimura, E.M.

    2012-01-01

    Full text: This work presents measurements of 222 Rn levels performed in La Carolina gold mine and Los Condores tungsten mine at the province of San Luis, Argentina, today used for tourist visitation, and can evaluate the potential use of such radioactive noble gas as tracer or marker for geological processes in underground environments. By concentrations of 40 K, 232 Th and 23 '8U were also measured in the walls of tunnels were determined the rocks mineral composition, what indicated that the mines have the same composition. In this sense, we used nuclear trace plastic detectors CR-39, gamma spectrometry of rock samples and Geiger-Muller (GM) monitors The patterns of radon gas transportation processes revealed that La Carolina could be interpreted through a model based on a radioactive gas confined into a single entrance tube, with constant cross section and air velocity. Los Condores, which has a second main entrance, could be interpreted through a model based on a radioactive gas confined into a two entrance tube, allowing a chimney effect for air circulation. The results showed the high potential of using 222 Rn as a geological tracer. In what concerns the occupational hazard, in summer (time of more intense tourist activity in the mine) La Carolina presented a mean concentration of the radioactive noble gas that exceeds in four times the action level of 1,5 kBq m -3 recommended by the International Commission of Radiological Protection (ICRP). The chimney effect shows the low mean concentration of radon in Los Condores. (author)

  19. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    International Nuclear Information System (INIS)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S.; Yamaguchi, M.

    2009-01-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  20. A monitoring system of radioactive tracers in hydroponic solution for research on plant physiology

    Energy Technology Data Exchange (ETDEWEB)

    Suzui, N.; Kawachi, N.; Ishioka, N.; Fujimaki, S. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2009-07-01

    The mechanism of nutrient uptake in plants has received considerable attention in the field of plant science. Here we describe the development of a new monitoring system of radioactive tracers in hydroponic solution, which enables the noninvasive measurement of radioactive tracer uptake by an intact plant. In addition, we incorporated a weighing instrument into this system in order to simultaneously monitor water uptake by the same plant. For an evaluation of this monitoring system, we conducted a tracer experiment with a rice plant and a positron-emitting radioactive tracer, and successfully obtained continuous data for the amounts of radioactive tracer and water taken up by the intact plant over 36 h. (authors)

  1. TransCom satellite intercomparison experiment: construction of a bias corrected atmospheric CO2 climatology

    NARCIS (Netherlands)

    Saito, R.; Houweling, S.; Patra, P. K.; Belikov, D.; Lokupitiya, R.; Niwa, Y.; Chevallier, F.; Saeki, T.; Maksyutov, S.

    2011-01-01

    A model-based three-dimensional (3-D) climatology of atmospheric CO2 concentrations has been constructed for the analysis of satellite observations, as a priori information in retrieval calculations, and for preliminary evaluation of remote sensing products. The locations of ground-based instruments

  2. Picture the Atmosphere: Adding the Arts to Weather, Climate, and Air Quality Learning Experiences

    Science.gov (United States)

    Gardiner, L. S.; Hatheway, B.; Ristvey, J. D., Jr.; Kirn, M.

    2017-12-01

    This presentation will highlight projects that connect visual arts and atmospheric science education - profiling varied strategies designed to help learners of all ages grow their understanding of weather, climate, and air quality with connections to the arts including (1) ways of combining art and geoscience in K-12 education, (2) methods of using art to communicate about science in museum exhibits and the web, and (3) opportunities for fostering a dialog between artists, geoscientists, and the public. For K-12 education, we have developed classroom resources that incorporate the arts in science learning in ways that help students grow their observational skills. Making observations of the environment is a skill that many artists and scientist share, although the observations are for different purposes. Emphasizing the observational skills that both artists and scientists use provides additional pathways for students to understand geoscience. For informal education, we have developed museum exhibits and content for websites and social media that utilize visual art and illustration to facilitate science communication. This allows explanation of atmospheric phenomena and processes that are too small to see, such as greenhouse gases trapping heat or ozone formation, or too large to see such as global atmospheric circulation. These illustrations also help connect with audiences that are not often drawn to geoscience. To foster a dialog between artists, geoscientists, and the public, we host temporary exhibits and public events at the National Center for Atmospheric Research Mesa Lab in Boulder, Colorado, that feature numerous exhibits highlighting connections between art and atmospheric science. This provides innovative opportunities for science education and communication and a forum for conversations between artists and scientists that provides people with different ways of exploring and describing the Earth to find common ground.

  3. Mars atmosphere studies with the OMEGA/Mars Express experiment: I. Overview and detection of lfuorescent emission by CO2

    Science.gov (United States)

    Drossart, P.; Combes, M.; Encrenaz, T.; Melchiorri, R.; Fouchet, T.; Forget, F.; Moroz, V.; Ignatiev, N.; Bibring, J.-P.; Langevin, Y.; OMEGA Team

    Observations of Mars by the OMEGA/Mars Express experiment provide extended maps of the martian disk at all latitudes, and with various conditions of illumination, between 0.4 to 5 micron. The atmospheric investigations so far conducted by our team are focussed on the infrared part of the spectrum (1-5 micron), and include: the development of a correction algorithm for atmospheric gaseous absorption, to give access to fine mineralogic studies, largely decorrelated from atmospheric effects the study of dust opacity effects in the near infrared, with the aim to correct also the rough spectra from dust opacity perturbation the study of minor constituents like CO, to search for regional or global variations the study of CO2 emission at 4.3 micron related to fluorescent emission This last effect is prominently detected in limb observations obtained in 3-axis stabilized mode of Mars Express, with high altitude emission in the CO2 fundamental at 4.3 micron, usually seen in absorption in nadir observations. These emissions are related to non-LTE atmospheric layers, well above the solid surface in the mesosphere. Such emissions are also present in Earth and Venus limb observations. They are present also in nadir observations, but are reinforced in limb viewing geometry due to the tangential view. A numerical model of these emission will be presented.

  4. The role of soil moisture in land surface-atmosphere coupling: climate model sensitivity experiments over India

    Science.gov (United States)

    Williams, Charles; Turner, Andrew

    2015-04-01

    It is generally acknowledged that anthropogenic land use changes, such as a shift from forested land into irrigated agriculture, may have an impact on regional climate and, in particular, rainfall patterns in both time and space. India provides an excellent example of a country in which widespread land use change has occurred during the last century, as the country tries to meet its growing demand for food. Of primary concern for agriculture is the Indian summer monsoon (ISM), which displays considerable seasonal and subseasonal variability. Although it is evident that changing rainfall variability will have a direct impact on land surface processes (such as soil moisture variability), the reverse impact is less well understood. However, the role of soil moisture in the coupling between the land surface and atmosphere needs to be properly explored before any potential impact of changing soil moisture variability on ISM rainfall can be understood. This paper attempts to address this issue, by conducting a number of sensitivity experiments using a state-of-the-art climate model from the UK Meteorological Office Hadley Centre: HadGEM2. Several experiments are undertaken, with the only difference between them being the extent to which soil moisture is coupled to the atmosphere. Firstly, the land surface is fully coupled to the atmosphere, globally (as in standard model configurations); secondly, the land surface is entirely uncoupled from the atmosphere, again globally, with soil moisture values being prescribed on a daily basis; thirdly, the land surface is uncoupled from the atmosphere over India but fully coupled elsewhere; and lastly, vice versa (i.e. the land surface is coupled to the atmosphere over India but uncoupled elsewhere). Early results from this study suggest certain 'hotspot' regions where the impact of soil moisture coupling/uncoupling may be important, and many of these regions coincide with previous studies. Focusing on the third experiment, i

  5. Development of Radioisotope Tracer Technology

    International Nuclear Information System (INIS)

    Jung, Sung Hee; Jin, Joon Ha; Kim, Jong Bum; Kim, Jin Seop; Kim, Jae Jo; Park, Soon Chul; Lim, Don Soon; Choi, Byung Jong; Jang, Dong Soon; Kim, Hye Sook

    2007-06-01

    The project is aimed to develop the radiotracer technology for process optimization and trouble-shooting to establish the environmental and industrial application of radiation and radioisotopes. The advanced equipment and software such as high speed data acquisition system, RTD model and high pressure injection tool have developed. Based on the various field application to the refinery/petrochemical industries, the developed technology was transfer to NDT company for commercial service. For the environmental application of radiotracer technology, injector, detector sled, core sampler, RI and GPS data logging system are developed and field tests were implemented successfully at Wolsung and Haeundae beach. Additionally tracer technology were also used for the performance test of the clarifier in a wastewater treatment plant and for the leak detection in reservoirs. From the experience of case studies on radiotracer experiment in waste water treatment facilities, 'The New Excellent Technology' is granted from the ministry of environment. For future technology, preliminary research for industrial gamma transmission and emission tomography which are new technology combined with radioisotope and image reconstruction are carried out

  6. The international INTRAVAL project. Phase 2, working group 1 report. Flow and tracer experiments in unsaturated tuff and soil. Las Cruces trench and Apache Leap tuff studies

    International Nuclear Information System (INIS)

    Nicholson, T.J.; Guzman-Guzman, A.; Hills, R.; Rasmussen, T.C.

    1997-01-01

    The Working Group 1 final report summaries two test case studies, the Las Cruces Trench (LCT), and Apache Leap Tuff Site (ALTS) experiments. The objectives of these two field studies were to evaluate models for water flow and contaminant transport in unsaturated, heterogeneous soils and fractured tuff. The LCT experiments were specifically designed to test various deterministic and stochastic models of water flow and solute transport in heterogeneous, unsaturated soils. Experimental data from the first tow LCT experiments, and detailed field characterisation studies provided information for developing and calibrating the models. Experimental results from the third experiment were held confidential from the modellers, and were used for model comparison. Comparative analyses included: point comparisons of water content; predicted mean behavior for water flow; point comparisons of solute concentrations; and predicted mean behavior for tritium transport. These analyses indicated that no model, whether uniform or heterogeneous, proved superior. Since the INTRAVAL study, however, a new method has been developed for conditioning the hydraulic properties used for flow and transport modelling based on the initial field-measured water content distributions and a set of scale-mean hydraulic parameters. Very good matches between the observed and simulated flow and transport behavior were obtained using the conditioning procedure, without model calibration. The ALTS experiments were designed to evaluate characterisation methods and their associated conceptual models for coupled matrix-fracture continua over a range of scales (i.e., 2.5 centimeter rock samples; 10 centimeter cores; 1 meter block; and 30 meter boreholes). Within these spatial scales, laboratory and field tests were conducted for estimating pneumatic, thermal, hydraulic, and transport property values for different conceptual models. The analyses included testing of current conceptual, mathematical and physical

  7. Atmospheric diffusion at coastal site in presence of sea-breeze

    International Nuclear Information System (INIS)

    Messaci, M.

    1987-03-01

    The coastal sites present special features so much by the dominant wind system then by the lower layers of the atmosphere. Two types of experiments were handled on a coastal site in presence of sea breeze. First, vertical atmospheric sounding by radiosounding and by throwing experimental balloons; then the discharge of tracer: the SF6. The first experiment lead us to put in a prominent position the Internal Boundary Layer and the determination of its height. Whereas the second experiment allowed us to estimate the diffusion parameters of the site as well as to obtain interesting conclusions on diffusivity of the environment studied and the influence of certain factors

  8. An Overview of the Regional Experiments for Land-atmosphere Exchanges 2012 (REFLEX 2012) Campaign

    Science.gov (United States)

    Timmermans, Wim J.; van der Tol, Christiaan; Timmermans, Joris; Ucer, Murat; Chen, Xuelong; Alonso, Luis; Moreno, Jose; Carrara, Arnaud; Lopez, Ramon; de la Cruz Tercero, Fernando; Corcoles, Horacio L.; de Miguel, Eduardo; Sanchez, Jose A. G.; Pérez, Irene; Franch, Belen; Munoz, Juan-Carlos J.; Skokovic, Drazen; Sobrino, Jose; Soria, Guillem; MacArthur, Alasdair; Vescovo, Loris; Reusen, Ils; Andreu, Ana; Burkart, Andreas; Cilia, Chiara; Contreras, Sergio; Corbari, Chiara; Calleja, Javier F.; Guzinski, Radoslaw; Hellmann, Christine; Herrmann, Ittai; Kerr, Gregoire; Lazar, Adina-Laura; Leutner, Benjamin; Mendiguren, Gorka; Nasilowska, Sylwia; Nieto, Hector; Pachego-Labrador, Javier; Pulanekar, Survana; Raj, Rahul; Schikling, Anke; Siegmann, Bastian; von Bueren, Stefanie; Su, Zhongbo (Bob)

    2015-12-01

    The REFLEX 2012 campaign was initiated as part of a training course on the organization of an airborne campaign to support advancement of the understanding of land-atmosphere interaction processes. This article describes the campaign, its objectives and observations, remote as well as in situ. The observations took place at the experimental Las Tiesas farm in an agricultural area in the south of Spain. During the period of ten days, measurements were made to capture the main processes controlling the local and regional land-atmosphere exchanges. Apart from multi-temporal, multi-directional and multi-spatial space-borne and airborne observations, measurements of the local meteorology, energy fluxes, soil temperature profiles, soil moisture profiles, surface temperature, canopy structure as well as leaf-level measurements were carried out. Additional thermo-dynamical monitoring took place at selected sites. After presenting the different types of measurements, some examples are given to illustrate the potential of the observations made.

  9. Development of Models to Simulate Tracer Tests for Characterization of Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Mark D.; Reimus, Paul; Vermeul, Vincent R.; Rose, Peter; Dean, Cynthia A.; Watson, Tom B.; Newell, D.; Leecaster, Kevin; Brauser, Eric

    2013-05-01

    A recent report found that power and heat produced from enhanced (or engineered) geothermal systems (EGSs) could have a major impact on the U.S energy production capability while having a minimal impact on the environment. EGS resources differ from high-grade hydrothermal resources in that they lack sufficient temperature distribution, permeability/porosity, fluid saturation, or recharge of reservoir fluids. Therefore, quantitative characterization of temperature distributions and the surface area available for heat transfer in EGS is necessary for the design and commercial development of the geothermal energy of a potential EGS site. The goal of this project is to provide integrated tracer and tracer interpretation tools to facilitate this characterization. This project was initially focused on tracer development with the application of perfluorinated tracer (PFT) compounds, non-reactive tracers used in numerous applications from atmospheric transport to underground leak detection, to geothermal systems, and evaluation of encapsulated PFTs that would release tracers at targeted reservoir temperatures. After the 2011 midyear review and subsequent discussions with the U.S. Department of Energy Geothermal Technology Program (GTP), emphasis was shifted to interpretive tool development, testing, and validation. Subsurface modeling capabilities are an important component of this project for both the design of suitable tracers and the interpretation of data from in situ tracer tests, be they single- or multi-well tests. The purpose of this report is to describe the results of the tracer and model development for simulating and conducting tracer tests for characterizing EGS parameters.

  10. Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

    International Nuclear Information System (INIS)

    Washington, W.M.; Meehl, G.A.

    1990-01-01

    The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming

  11. Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

    International Nuclear Information System (INIS)

    Washington, W.M.; Meehl, G.A.

    1991-01-01

    The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming. 46 refs.; 20 figs.; 1 tab

  12. METAALICUS : mercury experiment to assess atmospheric loading in Canada and the United States

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, J.W.M.; Kelly, C.A. [Department of Fisheries and Oceans, Ottawa, ON (Canada). Freshwater Inst.; Branfireun, B. [Toronto Univ., ON (Canada). Dept. of Geography; Gilmour, C.; Heyes, A. [Academy of Natural Sciences, Philadelphia, PA (United States); Harris, R. [Tetra Tech Inc., Pasadena, CA (United States); Hintelmann, H. [Trent Univ., Peterborough, ON (Canada). Dept. of Chemistry; Hurley, J.P. [Wisconsin Univ., Madison, WI (United States). Water Resources Inst.; Krabenhoft, D.P. [U.S. Geological Survey (United States); Lindberg, S. [Oak Ridge National Laboratory, TN (United States); St Louis, V.L. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Scott, K.J. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Microbiology

    2000-07-01

    Mercury emitted from coal-fired utilities is one of the major sources of anthropogenic mercury in the environment. Recently proposed control strategies for these emissions are expected to cost several billion dollars per year for North America alone. The major objective in controlling mercury emissions is to decrease levels of mercury in fish consumed by humans. However, since the actual relationship between atmospheric mercury deposition and fish mercury is still unknown, a unique whole-ecosystem study was conducted to address this issue. During the course of this study at the experimental Lakes Area in northwestern Ontario, the load of mercury in a small lake was increased by a factor of four to simulate the atmospheric loadings to lakes in northeastern North America. The mercury was added as three different stable isotopes to determine the most important sources of mercury to fish. The isotopes also made it possible to compare the availability of newly deposited mercury with old mercury stored in lake sediments and soils by analyzing mercury isotope patterns in biota. The response time in a catchment area to an increase in the rate of atmospheric deposition of mercury was calculated to determine if newly deposited mercury behaves in the same way as mercury that has accumulated in upland soils over many years.

  13. Atmospheric effects in astroparticle physics experiments and the challenge of ever greater precision in measurements

    Science.gov (United States)

    Louedec, Karim

    2015-01-01

    Astroparticle physics and cosmology allow us to scan the universe through multiple messengers. It is the combination of these probes that improves our understanding of the universe, both in its composition and its dynamics. Unlike other areas in science, research in astroparticle physics has a real originality in detection techniques, in infrastructure locations, and in the observed physical phenomenon that is not created directly by humans. It is these features that make the minimisation of statistical and systematic errors a perpetual challenge. In all these projects, the environment is turned into a detector medium or a target. The atmosphere is probably the environment component the most common in astroparticle physics and requires a continuous monitoring of its properties to minimise as much as possible the systematic uncertainties associated. This paper introduces the different atmospheric effects to take into account in astroparticle physics measurements and provides a non-exhaustive list of techniques and instruments to monitor the different elements composing the atmosphere. A discussion on the close link between astroparticle physics and Earth sciences ends this paper.

  14. Experiences with the Haertel-Truebungstest at diagnosing injuries to spruce caused by atmospheric pollution

    Energy Technology Data Exchange (ETDEWEB)

    Pelz, E

    1958-01-01

    The Haertel-Truebungstest is based on the observation that spruce needles secrete more wax at the stomata in areas affected by atmospheric pollution than in areas without. The increased secretion of wax is taken for a symptom of injury caused by atmospheric pollution. The wax is extracted in boiling water and, after cooling down, the turbidity of the extract is measured quantitatively in a photometer. Investigations on spruce in Saxony and Thuringia confirm the tendency to increasing turbidity towards the source of smoke. A considerable dispersion of turbidity values however impairs the results of this method, so that a great number of samples must be used in order to find out a trend. The dispersion of turbidity values in spruce forests that are not directly influenced by atmospheric pollution substantially exceeds the dispersion of the +/- 1% of the turbidity value that was found by Haertel. As was stated by Haertel and Papesch, the dispersion of individual turbidity values grows with increasing doses of SO/sub 2/. In Saxony the individual smoke emissions so densely cover one another, that there are scarcely any areas without air pollution and, probably, a relation exists between this continuous influence of smoke and SO/sub 2/ and the dispersion of turbidity values. It may be, however, that the environmental factors have also a certain influence, as, on vast areas of Saxony, spruce is growing on sites that are not its natural habitat.

  15. Tracer dating and ocean ventilation

    International Nuclear Information System (INIS)

    Thiele, G.; Sarmiento, J.L.

    1990-01-01

    The interpretation of transient tracer observations depends on difficult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. The authors use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. The authors define an idealized ventilation age tracer that is conservative with respect to mixing, and they explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters

  16. Polar organic marker compounds in atmospheric aerosols during the LBA-SMOCC 2002 biomass burning experiment in Rondônia, Brazil: sources and source processes, time series, diel variations and size distributions

    Directory of Open Access Journals (Sweden)

    M. Claeys

    2010-10-01

    Full Text Available Measurements of polar organic marker compounds were performed on aerosols that were collected at a pasture site in the Amazon basin (Rondônia, Brazil using a high-volume dichotomous sampler (HVDS and a Micro-Orifice Uniform Deposit Impactor (MOUDI within the framework of the 2002 LBA-SMOCC (Large-Scale Biosphere Atmosphere Experiment in Amazônia – Smoke Aerosols, Clouds, Rainfall, and Climate: Aerosols From Biomass Burning Perturb Global and Regional Climate campaign. The campaign spanned the late dry season (biomass burning, a transition period, and the onset of the wet season (clean conditions. In the present study a more detailed discussion is presented compared to previous reports on the behavior of selected polar marker compounds, including levoglucosan, malic acid, isoprene secondary organic aerosol (SOA tracers and tracers for fungal spores. The tracer data are discussed taking into account new insights that recently became available into their stability and/or aerosol formation processes. During all three periods, levoglucosan was the most dominant identified organic species in the PM2.5 size fraction of the HVDS samples. In the dry period levoglucosan reached concentrations of up to 7.5 μg m−3 and exhibited diel variations with a nighttime prevalence. It was closely associated with the PM mass in the size-segregated samples and was mainly present in the fine mode, except during the wet period where it peaked in the coarse mode. Isoprene SOA tracers showed an average concentration of 250 ng m−3 during the dry period versus 157 ng m−3 during the transition period and 52 ng m−3 during the wet period. Malic acid and the 2-methyltetrols exhibited a different size distribution pattern, which is consistent with different aerosol formation processes (i.e., gas-to-particle partitioning in the case of malic acid and heterogeneous formation from gas-phase precursors in the case of

  17. Radon-222 and beryllium-7 as natural tracer; Radon-222 und Beryllium-7 als natuerliche Tracer

    Energy Technology Data Exchange (ETDEWEB)

    Frank, G.; Steinkopff, T. [Deutscher Wetterdienst, Offenbach (Germany). Radioaktivitaetsueberwachung; Salvamoser, J. [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen (IGU), Woerthsee (Germany)

    2016-07-01

    The Global Atmosphere Watch Program (GAW) is intended to analyse worldwide the influence of anthropogenic emissions to the atmosphere. Data are continuously transferred to the ''World Data Centre for Green House Gases'' of the WMO. For the study of atmospheric transports the natural radionuclides Rn-222, Be-7, Pb-210, Pb- 214 and Bi-214 are continuously measured at the Umweltforschungsstation Schneefernerhaus (2650 m) and at the Zugspitze (2962 m) by the Deutscher Wetterdienst (DWD, German Weather Service). The measurements support the classification of atmospheric transport, atmospheric dilution and dispersion models of gaseous and aerosol bond micro pollutants. Results are carried out in combination with meteorological data. It is shown the optimization and effect of a new sampling site for the measurement of Rn-222 activity at the Zugspitze. Results of Rn-222 and Be-7 concentrations are shown in relation to horizontal and vertical dispersion of air masses. The origin of natural Rn-222 and Be-7 are known, therefore both nuclides are well suited for the research of atmospheric transport. Rn-222 is an ideal tracer, because there is no influence by atmospheric processes (chemical processes, wash out effects).

  18. Atmospheric response in aurora experiment: Observations of E and F region neutral winds in a region of postmidnight diffuse aurora

    International Nuclear Information System (INIS)

    Larsen, M.F.; Marshall, T.R.; Mikkelsen, I.S.

    1995-01-01

    The goal of the Atmospheric Response in Aurora (ARIA) experiment carried out at Poker Flat, Alaska, on March 3, 1992, was to determine the response of the neutral atmosphere to the long-lived, large-scale forcing that is characteristic of the diffuse aurora in the postmidnight sector. A combination of chemical release rocket wind measurements, intrumented rocket composition measurements, and ground-based optical measurements were used to characterize the response of the neutral atmosphere. The rocket measurements were made at the end of a 90-min period of strong Joule heating. We focus on the neutral wind measurements made with the rocket. The forcing was determined by running the assimilated mapping of ionospheric electrodynamics (AMIE) analysis procedure developed at the National Center for Atmospheric Research. The winds expected at the latitude and longitude of the experiment were calculated using the spectral thermospheric general circulation model developed at the Danish Meteorological Institute. Comparisons of the observations and the model suggest that the neutral winds responded strongly in two height ranges. An eastward wind perturbation of ∼100 m s -1 developed between 140 and 200 km altitude with a peak near 160 km. A southwestward wind with peak magnitude of ∼150 m s -1 developed near 115 km altitude. The large amplitude winds at the lower altitude are particularly surprising. They appear to be associated with the upward propagating semidiurnal tide. However, the amplitude is much larger than predicted by any of the tidal models, and the shear found just below the peak in the winds was nomially unstable with a Richardson number of ∼0.08. 17 refs., 12 figs

  19. The use of nonlinear regression analysis for integrating pollutant concentration measurements with atmospheric dispersion modeling for source term estimation

    International Nuclear Information System (INIS)

    Edwards, L.L.; Freis, R.P.; Peters, L.G.; Gudiksen, P.H.; Pitovranov, S.E.

    1993-01-01

    The accuracy associated with assessing the environmental consequences of an accidental release of radioactivity is highly dependent on the knowledge of the source term characteristics, which are generally poorly known. The development of an automated numerical technique that integrates the radiological measurements with atmospheric dispersion modeling for more accurate source term estimation is reported. Often, this process of parameter estimation is performed by an emergency response assessor, who takes an intelligent first guess at the model parameters, then, comparing the model results with whatever measurements are available, makes an intuitive, informed next guess of the model parameters. This process may be repeated any number of times until the assessor feels that the model results are reasonable in terms of the measured observations. A new approach, based on a nonlinear least-squares regression scheme coupled with the existing Atmospheric Release Advisory Capability three-dimensional atmospheric dispersion models, is to supplement the assessor's intuition with automated mathematical methods that do not significantly increase the response time of the existing predictive models. The viability of the approach is evaluated by estimation of the known SF 6 tracer release rates associated with the Mesoscale Atmospheric Transport Studies tracer experiments conducted at the Savannah River Laboratory during 1983. These 19 experiments resulted in 14 successful, separate tracer releases with sampling of the tracer plumes along the cross-plume arc situated ∼30 km from the release site

  20. Tracer research in process engineering

    International Nuclear Information System (INIS)

    Iller, E.

    1992-01-01

    The book is a review of modern applications of tracer techniques in chemical and process engineering studies. The next topics have been extensively presented: 1) media flow through apparatus; 2) the tracers in the study of media flow dynamics through apparatus; 3) mathematical interpretation of experimental data from impulse-response method; 4) the models of media flow through chemical reactors and apparatus; 5) radiotracers in mass transport study; 6) examples of practical applications of tracer methods in industrial objects. 84 refs, 96 figs, 31 tabs

  1. Environment tracers application to groundwater circulation assessment in an alluvial aquifer in Central Italy

    Science.gov (United States)

    Sappa, Giuseppe; Barbieri, Maurizio; Vitale, Stefania

    2017-04-01

    Groundwater vulnerability assessment is an important tool in order to plan any groundwater protection strategy. The aim of this study is to experiment a specific approach to give a conceptual model about groundwater circulation characterization. This approach has been applied to a suspected contaminated site in a large alluvial plan, made of sediments coming from weathered volcanic rocks, laying on marine sediments, where more than thirty years ago had been built a very important urban waste solid landfill. In referring to this case history it has been pointed out the importance of natural chemical interaction between ground water and rock mass, especially when pyroclastic origin sediments are involved. The landfill had been isolated from the surrounding environment, especially to protect aquifers, by a waterproof diaphragm This land is characterised by intensive agricultural and industrial activities (oil refineries, medical waste incinerators, concrete production, tar factory). The study will highlight the importance of environmental tracers which provide information about the flow and mixing processes of water coming from different sources. They are also useful to point out directions of groundwater flow and to determine origin Environmental tracers are natural chemical and isotopic substances that can be measured in groundwater and used to understand hydrologic properties of aquifers. They may be input into the hydrological system from the atmosphere at recharge and/or are added/lost/exchanged inherently as waters flow over and through materials. Variations in their chemical abundances and isotopic compositions can be used as tracers to determine sources (provenance), pathways (of reaction or interaction) and also timescales (dating) of environmental processes. In combination with these, the basic idea is to use. In this case enviromental tracers have been integrated by temperature and electric conductivity logs, to better investigate different levels of faster

  2. Tracer studies with aortic infusion result in improper tracer distribution

    International Nuclear Information System (INIS)

    Wisneski, J.A.; Brooks, G.A.; Neese, R.A.; Stanley, W.C.; Morris, D.L.; Gertz, E.W.

    1986-01-01

    It has been suggested that lactate turnover can be accurately assessed by infusing radioactive lactate tracer into the aorta and sampling blood in the vena cava. However, there may be streaming of newly infused tracer in the aorta, resulting in a nonuniform arterial specific activity (SA). Furthermore vena caval blood may not be representative of mixed venous blood. The authors examined this problem in 7 anesthetized dogs with sampling catheters in the pulmonary (PA), carotid (CA), and femoral (FA) arteries, and the superior (SVC) and inferior (IVC) vena cavi. [1- 14 C]lactate was continuously infused into the left ventricle through a catheter introduced through the femoral artery. The same SA (dpm/μmol) was found in the CA and FA, indicating adequate mixing of newly infused tracer with trace. Three dogs showed differences between SVC, IVC and PA, suggesting a mixed venous sample can not be obtained from the VC. When the catheter was moved into the aorta, wide differences in SA appeared between the CA and FA, clearly reflecting streaming of tracer. These differences also appeared in the SVC and IVC. In conclusion, adequate mixing does not occur between tracer and trace in arterial blood with aortic infusion. Further, VC sampling will not give a consistent mixed venous SA. Therefore, for practical reasons, aortic tracer infusion with vena caval sampling will lead to erroneous turnover values

  3. The atmospheric inventory of Xenon and noble cases in shales The plastic bag experiment

    Science.gov (United States)

    Bernatowicz, T. J.; Podosek, F. A.; Honda, M.; Kramer, F. E.

    1984-01-01

    A novel trapped gas analysis protocol is applied to five shales in which the samples are sealed in air to eliminate the possibility of gas loss in the preanalysis laboratory vacuum exposure of a conventional protocol. The test is aimed at a determination concerning the hypothesis that atmospheric noble gases occur in the same proportion as planetary gases in meteorites, and that the factor-of-23 deficiency of air Xe relative to planetary Xe is made up by Xe stored in shales or other sedimentary rocks. The results obtained do not support the shale hypothesis.

  4. Compartmental modeling and tracer kinetics

    CERN Document Server

    Anderson, David H

    1983-01-01

    This monograph is concerned with mathematical aspects of compartmental an­ alysis. In particular, linear models are closely analyzed since they are fully justifiable as an investigative tool in tracer experiments. The objective of the monograph is to bring the reader up to date on some of the current mathematical prob­ lems of interest in compartmental analysis. This is accomplished by reviewing mathematical developments in the literature, especially over the last 10-15 years, and by presenting some new thoughts and directions for future mathematical research. These notes started as a series of lectures that I gave while visiting with the Division of Applied ~1athematics, Brown University, 1979, and have developed in­ to this collection of articles aimed at the reader with a beginning graduate level background in mathematics. The text can be used as a self-paced reading course. With this in mind, exercises have been appropriately placed throughout the notes. As an aid in reading the material, the e~d of a ...

  5. Effect on tracer concentrations of ABL depth models in complex terrain

    Energy Technology Data Exchange (ETDEWEB)

    Galmarini, S.; Salin, P. [Joint Research Center Ispra (Italy); Anfossi, D.; Trini-Castelli, S. [CNR-ICGF, Turin (Italy); Schayes, G. [Univ. Louvain-la-Neuve, Louvain (Belgium)

    1997-10-01

    In the present preliminary study we use different ABL (atmospheric boundary layer) depth formulations to study atmospheric dispersion in complex-terrain conditions. The flow in an Alpine valley during the tracer experiment TRANSALP is simulated by means of a mesoscale model and a tracer dispersion is reproduced using a Lagrangian particle model. The ABL dept enters as key parameter in particle model turbulent-dispersion formulation. The preliminary results reveal that the ABL depth parameter can influence the dispersion process but that in the case of a dispersion in a valley-daytime flow the results depend much more strongly on the model horizontal and vertical resolution. A relatively coarse horizontal resolution implies a considerable smoothing of the topography that largely affects the dispersion characteristics. The vertical resolution does not allow on to resolve with sufficient details the rapid and large variation of the flow characteristic as the terrain feature vary. Two of the methods used to determine the ABL depth depend strongly on the resolution. The method that instead depends only on surface parameters like heat flux and surface based stability allowed us to obtain results to be considered satisfactory for what concerns the dispersion process, quite consistent with the flow model results, less numeric dependent and more physically sound. (LN)

  6. The Effectiveness of Rotating Tank Experiments in Teaching Undergraduate Courses in Atmospheres, Oceans, and Climate Sciences

    Science.gov (United States)

    Mackin, Kathleen J.; Cook-Smith, Nancy; Illari, Lodovica; Marshall, John; Sadler, Philip

    2012-01-01

    While it is commonly recognized that laboratory experiments and demonstrations have made a considerable contribution to our understanding of fluid dynamics, few U.S. universities that offer courses in meteorology and/or oceanography provide opportunities for students to observe fluid experiments in the classroom. This article explores the…

  7. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    International Nuclear Information System (INIS)

    Alizadeh, E.; Sanche, L.

    2014-01-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N 2 , O 2 , H 2 O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N 2 had little effect on the yields of LEE-induced single and double strand breaks, both O 2 and H 2 O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O 2 and H 2 O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitization of these agents in chemo-radiation cancer therapy. (authors)

  8. Low-energy-electron interactions with DNA: approaching cellular conditions with atmospheric experiments

    Science.gov (United States)

    Alizadeh, Elahe; Sanche, Léon

    2014-04-01

    A novel technique has been developed to investigate low energy electron (LEE)-DNA interactions in the presence of small biomolecules (e.g., N2, O2, H2O) found near DNA in the cell nucleus, in order to simulate cellular conditions. In this technique, LEEs are emitted from a metallic surface exposed by soft X-rays and interact with DNA thin films at standard ambient temperature and pressure (SATP). Whereas atmospheric N2 had little effect on the yields of LEE-induced single and double strand breaks, both O2 and H2O considerably modified and increased such damage. The highest yields were obtained when DNA is embedded in a combined O2 and H2O atmosphere. In this case, the amount of additional double strand breaks was supper-additive. The effect of modifying the chemical and physical stability of DNA by platinum-based chemotherapeutic agents (Pt-drugs) including cisplatin, carboplatin and oxaliplatin was also investigated with this technique. The results obtained provide information on the role played by subexcitation-energy electrons and dissociative electron attachment in the radiosensitization of DNA by Pt-drugs, which is an important step to unravel the mechanisms of radiosensitisation of these agents in chemoradiation cancer therapy.

  9. Comparative calculations and validation studies with atmospheric dispersion models

    International Nuclear Information System (INIS)

    Paesler-Sauer, J.

    1986-11-01

    This report presents the results of an intercomparison of different mesoscale dispersion models and measured data of tracer experiments. The types of models taking part in the intercomparison are Gaussian-type, numerical Eulerian, and Lagrangian dispersion models. They are suited for the calculation of the atmospherical transport of radionuclides released from a nuclear installation. For the model intercomparison artificial meteorological situations were defined and corresponding arithmetical problems were formulated. For the purpose of model validation real dispersion situations of tracer experiments were used as input data for model calculations; in these cases calculated and measured time-integrated concentrations close to the ground are compared. Finally a valuation of the models concerning their efficiency in solving the problems is carried out by the aid of objective methods. (orig./HP) [de

  10. 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.

  11. Tracer transport in fractured rocks

    International Nuclear Information System (INIS)

    Tsang, C.F.; Tsang, Y.W.; Hale, F.V.

    1988-07-01

    Recent interest in the safety of toxic waste underground disposal and nuclear waste geologic repositories has motivated many studies of tracer transport in fractured media. Fractures occur in most geologic formations and introduce a high degree of heterogeneity. Within each fracture, the aperture is not constant in value but strongly varying. Thus for such media, tracer tends to flow through preferred flowpaths or channels within the fractures. Along each of these channels, the aperture is also strongly varying. A detailed analysis is carried out on a 2D single fracture with variable apertures and the flow through channels is demonstrated. The channels defined this way are not rigidly set pathways for tracer transport, but are the preferred flow paths in the sense of stream-tubes in the potential theory. It is shown that such variable-aperture channels can be characterized by an aperture probability distribution function, and not by the exact deterministic geometric locations. We also demonstrate that the 2D tracer transport in a fracture can be calculated by a model of a system of 1D channels characterized by this distribution function only. Due to the channeling character of tracer transport in fractured rock, random point measurements of tracer breakthrough curves may give results with a wide spread in value due to statistical fluctuations. The present paper suggests that such a wide spread can probably be greatly reduced by making line/areal (or multiple) measurements covering a few spatial correlation lengths. 13 refs., 11 figs., 1 tab

  12. Dependence of the muon intensity on the atmospheric temperature measured by the GRAPES-3 experiment

    Science.gov (United States)

    Arunbabu, K. P.; Ahmad, S.; Chandra, A.; Dugad, S. R.; Gupta, S. K.; Hariharan, B.; Hayashi, Y.; Jagadeesan, P.; Jain, A.; Jhansi, V. B.; Kawakami, S.; Kojima, H.; Mohanty, P. K.; Morris, S. D.; Nayak, P. K.; Oshima, A.; Rao, B. S.; Reddy, L. V.; Shibata, S.; Tanaka, K.; Zuberi, M.

    2017-09-01

    The large area (560 m2) GRAPES-3 tracking muon telescope has been operating uninterruptedly at Ooty, India since 2001. Every day, it records 4 × 109 muons of ≥1 GeV with an angular resolution of ∼4°. The variation of atmospheric temperature affects the rate of decay of muons produced by the galactic cosmic rays (GCRs), which in turn modulates the muon intensity. By analyzing the GRAPES-3 data of six years (2005-2010), a small (amplitude ∼0.2%) seasonal variation (1 year (Yr) period) in the intensity of muons could be measured. The effective temperature 'Teff' of the upper atmosphere also displays a periodic variation with an amplitude of ∼1 K which was responsible for the observed seasonal variation in the muon intensity. At GeV energies, the muons detected by the GRAPES-3 are expected to be anti-correlated with Teff. The anti-correlation between the seasonal variation of Teff, and the muon intensity was used to measure the temperature coefficient αT by fast Fourier transform (FFT) technique. The magnitude of αT was found to scale with the assumed attenuation length 'λ' of the hadrons in the range λ = 80-180 g cm-2. However, the magnitude of the correction in the muon intensity was found to be almost independent of the value of λ used. For λ = 120 g cm-2 the value of temperature coefficient αT was found to be (- 0.17 ± 0.02)% K-1.

  13. The WELSONS experiment: overview and presentation of first results on the surface atmospheric boundary-layer in semiarid Spain

    Directory of Open Access Journals (Sweden)

    J.-P. Frangi

    Full Text Available This study presents the preliminary results of the local energy budget and dynamic characteristics of the surface atmospheric boundary-layer (SBL during the WELSONS (wind erosion and losses of soil nutrients in semiarid Spain experiment. Some Mediterranean regions suffer land degradation by wind erosion as a consequence of their particular soil and climate conditions and inappropriate agricultural practice. In Spain, where land degradation by water erosion is well known, the lack of field studies to quantify soils losses by wind erosion resulted in the European Community organizing a scientific program for this specific issue. The European programme known as WELSONS was devoted to study the wind erosion process in central Aragon (NE Spain. This multidisciplinary experiment, which began in 1996 and finished in 1998, was carried out over an agricultural soil which was left fallow. Within the experimental field, two plots were delimited where two tillage treatments were applied, a mould-board ploughing (or conventional tillage denoted CT and chisel ploughing (reduced tillage denoted RT. This was to study on bare soil the influence of tillage method on surface conditions, saltation flux, vertical dust flux, erosion rates, dynamics characteristics such as friction velocity, roughness length, etc., and energy budget. The partitioning of the available energy, resulting from the dynamics of the SBL, are quite different over the two plots because of their own peculiar soil and surface properties. The first results show that the RT treatment seems to provide a wind erosion protection. Because of the long data recording time and particular phenomena (formation of a crust at the soil surface, very dry conditions, high wind speed for instance, these microclimatological data acquired during the WELSONS programmes may be helpful to test atmospheric boundary-layer models coupled with soil models.

    Key words: Hydrology (desertification - Meterology and

  14. The WELSONS experiment: overview and presentation of first results on the surface atmospheric boundary-layer in semiarid Spain

    Directory of Open Access Journals (Sweden)

    J.-P. Frangi

    2000-03-01

    Full Text Available This study presents the preliminary results of the local energy budget and dynamic characteristics of the surface atmospheric boundary-layer (SBL during the WELSONS (wind erosion and losses of soil nutrients in semiarid Spain experiment. Some Mediterranean regions suffer land degradation by wind erosion as a consequence of their particular soil and climate conditions and inappropriate agricultural practice. In Spain, where land degradation by water erosion is well known, the lack of field studies to quantify soils losses by wind erosion resulted in the European Community organizing a scientific program for this specific issue. The European programme known as WELSONS was devoted to study the wind erosion process in central Aragon (NE Spain. This multidisciplinary experiment, which began in 1996 and finished in 1998, was carried out over an agricultural soil which was left fallow. Within the experimental field, two plots were delimited where two tillage treatments were applied, a mould-board ploughing (or conventional tillage denoted CT and chisel ploughing (reduced tillage denoted RT. This was to study on bare soil the influence of tillage method on surface conditions, saltation flux, vertical dust flux, erosion rates, dynamics characteristics such as friction velocity, roughness length, etc., and energy budget. The partitioning of the available energy, resulting from the dynamics of the SBL, are quite different over the two plots because of their own peculiar soil and surface properties. The first results show that the RT treatment seems to provide a wind erosion protection. Because of the long data recording time and particular phenomena (formation of a crust at the soil surface, very dry conditions, high wind speed for instance, these microclimatological data acquired during the WELSONS programmes may be helpful to test atmospheric boundary-layer models coupled with soil models.Key words: Hydrology (desertification - Meterology and atmospheric

  15. THERMAL RESPONSE OF A SOLAR-LIKE ATMOSPHERE TO AN ELECTRON BEAM FROM A HOT JUPITER: A NUMERICAL EXPERIMENT

    International Nuclear Information System (INIS)

    Gu, P.-G.; Suzuki, Takeru K.

    2009-01-01

    We investigate the thermal response of the atmosphere of a solar-type star to an electron beam injected from a hot Jupiter by performing a one-dimensional MHD numerical experiment with nonlinear wave dissipation, radiative cooling, and thermal conduction. In our experiment, the stellar atmosphere is non-rotating and is modeled as a one-dimensional open flux tube expanding super-radially from the stellar photosphere to the planet. An electron beam is assumed to be generated from the reconnection site of the planet's magnetosphere. The effects of the electron beam are then implemented in our simulation as dissipation of the beam momentum and energy at the base of the corona where the Coulomb collisions become effective. When the sufficient energy is supplied by the electron beam, a warm region forms in the chromosphere. This warm region greatly enhances the radiative fluxes corresponding to the temperature of the chromosphere and transition region. The warm region can also intermittently contribute to the radiative flux associated with the coronal temperature due to the thermal instability. However, owing to the small area of the heating spot, the total luminosity of the beam-induced chromospheric radiation is several orders of magnitude smaller than the observed Ca II emissions from HD 179949.

  16. Global atmospheric response to specific linear combinations of the main SST modes. Part I: numerical experiments and preliminary results

    Directory of Open Access Journals (Sweden)

    S. Trzaska

    1996-10-01

    Full Text Available This article investigates through numerical experiments the controversial question of the impact of El Niño-Southern Oscillation (ENSO phenomena on climate according to large-scale and regional-scale interhemispheric thermal contrast. Eight experiments (two considering only inversed Atlantic thermal anomalies and six combining ENSO warm phase with large-scale interhemispheric contrast and Atlantic anomaly patterns were performed with the Météo-France atmospheric general circulation model. The definition of boundary conditions from observed composites and principal components is presented and preliminary results concerning the month of August, especially over West Africa and the equatorial Atlantic are discussed. Results are coherent with observations and show that interhemispheric and regional scale sea-surface-temperature anomaly (SST patterns could significantly modulate the impact of ENSO phenomena: the impact of warm-phase ENSO, relative to the atmospheric model intercomparison project (AMIP climatology, seems stronger when embedded in global and regional SSTA patterns representative of the post-1970 conditions [i.e. with temperatures warmer (colder than the long-term mean in the southern hemisphere (northern hemisphere]. Atlantic SSTAs may also play a significant role.

  17. Measurement of open streams by using tracers

    International Nuclear Information System (INIS)

    Ramos, German F.; Tarquino, W.; Curcuy, H.; Orozco, C.

    1999-01-01

    This paper presents an intercomparison study to be carried out between flux measurements by using tracers and moulinet. This intercomparison is scheduled to be performed at the measurement station belonging to the National Service of Meteorology and Hydrology (SENAMHI). Two techniques of tracer dilution are outstanded: total evaluation with tracer punctual injection and punctual evaluation with tracer continuous injection. Total evaluation with tracer punctual injection has been used since this technique is considered to be more suitable for hydrology purposes

  18. An experimental study of tracers for labelling of injection gas in oil reservoirs

    International Nuclear Information System (INIS)

    Dugstad, Oe.

    1992-01-01

    This work demonstrates the feasibility of the PMCP and PMCH as tracers in field experiments. These compounds have properties which make them as well suited for well to well studies as the more common tracers CH 3 T and 85 Kr. In an injection project carried out at the Gullfaks field in the North Sea the two PFCs verified communication between wells. This implies communication between different geological layers in the reservoir and also communication across faults within the same layers. Laboratory studies carried out have focused on the retention of the tracers in dynamic flooding experiments under conditions comparable with those in the petroleum reservoirs. Simultaneous injection of a variety of tracers has shown individual variations in tracer retention which are caused by important reservoir parameters as fluid saturation and rock properties. By proper design of field injection programs the tracers response may therefore be used to estimate fluid saturation if actual rock properties are known. 45 refs., 20 figs., 13 tabs

  19. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.

    1997-01-01

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  20. Joint interpretation of two tracer tests with reversed flow fields

    International Nuclear Information System (INIS)

    Kunstmann, H.; Kinzelbach, W.; Marschall, P.; Li, G.

    1995-01-01

    Two dipole tracer experiments were performed in a fractured rock at the Grimsel Test Site in February/March 1993. In both experiments NaCl was used as a tracer. The extraction rate was twice the injection rate. In the second experiment injection and extraction were interchanged (Reverse-Experiment). Long tailing was characteristic for the breakthrough curves in both experiments. The tests were interpreted using a single fracture flow model. Tracer transport is described by advection/dispersion along the fracture allowing for diffusion into an immobile matrix. The authors were able to interpret the breakthrough curves for both experiments by one unique set of parameters, describing transport and baseflow. Uniqueness could only be achieved when using the information of both experiments. The authors conclude that performing a Reverse-Experiment is an indispensable tool for parameter identification in dipole tracer tests. A sensitivity analysis suggested that not only matrix diffusion is responsible for the tailing in the breakthrough curves but also transversal dispersivity. Further, the typical exchange time between mobile and immobile media was too small to be attributed to matrix diffusion in the strict sense which will cause tailing even at large spatial and temporal scales. Analysis of the covariance matrices showed that the parameters have small errors but high correlation

  1. Natural stream flow-rates measurements by tracer techniques

    International Nuclear Information System (INIS)

    Cuellar Mansilla, J.

    1982-01-01

    This paper presents the study of the precision obtained measuring the natural stream flow rates by tracer techniques, especially when the system presents a great slope and a bed constituted by large and extended particle size. The experiences were realized in laboratory pilot channels with flow-rates between 15 and 130 [1/s]; and in natural streams with flow-rates from 1 to 25 m 3 /s. Tracer used were In-133m and Br-82 for laboratory and field measurements respectively. In both cases the tracer was injected as a pulse and its dilution measured collecting samples in the measured section, at constant flow-rates, of 5[1] in laboratory experiences and 60[1] of water in field experiences. Precisions obtained at a 95% confidence level were about 2% for laboratory and 3% for field. (I.V.)

  2. Determination of the self purification of streams using tracers

    International Nuclear Information System (INIS)

    Salviano, J.S.

    1982-04-01

    A methodology for the 'in situ' evaluation of the self purification of streams is discussed. It consists of the simultaneous injection of two tracers into the stream. One of the tracers is oxidized by biochemical processes. It can be either artificially supplied to the stream or a naturally present component can be used. This tracer is used for the determination of the self purification parameters. The other tracer is conservative and allows for the hydrodynamic effects. Tests have been carried out in two streams with quite different hydrodynamic and physicochemical conditions. In the first stream, with a flow-rate of about 0.9 m 3 /s, urea was used as the nonconservative tracer. In the other stream, which had a flow-rate of about 5 m 3 /s, only a radioactive tracer has been used, and the rate of biochemical oxidation has been determined from BOD measurements. Calculations have been implemented on a digital computer. In both cases it was found that the reoxygenation rate is more conveniently determined by empirical formulas. Results from both tests have been deemed realistic by comparison with similar experiments. (Author) [pt

  3. Quantifying solute transport processes: are chemically "conservative" tracers electrically conservative?

    Science.gov (United States)

    Singha, Kamini; Li, Li; Day-Lewis, Frederick D.; Regberg, Aaron B.

    2012-01-01

    The concept of a nonreactive or conservative tracer, commonly invoked in investigations of solute transport, requires additional study in the context of electrical geophysical monitoring. Tracers that are commonly considered conservative may undergo reactive processes, such as ion exchange, thus changing the aqueous composition of the system. As a result, the measured electrical conductivity may reflect not only solute transport but also reactive processes. We have evaluated the impacts of ion exchange reactions, rate-limited mass transfer, and surface conduction on quantifying tracer mass, mean arrival time, and temporal variance in laboratory-scale column experiments. Numerical examples showed that (1) ion exchange can lead to resistivity-estimated tracer mass, velocity, and dispersivity that may be inaccurate; (2) mass transfer leads to an overestimate in the mobile tracer mass and an underestimate in velocity when using electrical methods; and (3) surface conductance does not notably affect estimated moments when high-concentration tracers are used, although this phenomenon may be important at low concentrations or in sediments with high and/or spatially variable cation-exchange capacity. In all cases, colocated groundwater concentration measurements are of high importance for interpreting geophysical data with respect to the controlling transport processes of interest.

  4. Choosing the best meteorological conditions for atmospheric diffusion experiments at the Angra site

    International Nuclear Information System (INIS)

    Nicolli, D.; Thomas, P.

    1983-01-01

    The most appropriate meteorological conditions and time of the day advisable for carrying out diffusion experiments at the Angra site are described. Two emission points were defined, and the sampling area was determined with easy access to the complex terrain taken into consideration. The onsite meteorological measuring system is briefly described. (Author) [pt

  5. Dust ablation laboratory experiments to measure the plasma and light production of meteoroids in the atmosphere

    Science.gov (United States)

    Sternovsky, Z.; DeLuca, M.; Janches, D.; Marshall, R. A.; Munsat, T.; Plane, J. M. C.; Horanyi, M.

    2017-12-01

    Radars play an important role in characterizing the distribution of meteoroids entering Earth's atmosphere, and they are sensitive to the size range where most of the mass input occurs. The interpretation of meteor radar measurements, however, is handicapped by the incomplete understanding of the microphysical processes relevant to meteoric ablation. A facility has been developed to simulate the ablation of small dust particles in laboratory conditions and to determine the most critical parameters. An electrostatic dust accelerator is used to generate iron, aluminum and meteoric analog particles with velocities of 1-70 km/s. The particles are then introduced into a cell filled with nitrogen, air, oxygen, or carbon dioxide gas with pressures adjustable in the 0.02 - 0.5 Torr range, where partial or complete ablation occurs over a short distance. An array of biased electrodes is used to collect the ionized products with spatial resolution along the ablating particles' path. An optical observation setup using a 64 channel PMT system allows direct observation of the particle and estimating the light output. A new addition to the facility, using pickup tube detectors and precise timing, allows measurement of the drag coefficient of the particle's slowdown, which we find to be significantly higher than commonly used in existing models. Measurements also indicated that the ionization efficiency of iron and aluminum at low velocities is larger than previously expected.

  6. An overview of organically bound tritium experiments in plants following a short atmospheric HTO exposure.

    Science.gov (United States)

    Galeriu, D; Melintescu, A; Strack, S; Atarashi-Andoh, M; Kim, S B

    2013-04-01

    The need for a less conservative, but reliable risk assessment of accidental tritium releases is emphasized in the present debate on the nuclear energy future. The development of a standard conceptual model for accidental tritium releases must be based on the process level analysis and the appropriate experimental database. Tritium transfer from atmosphere to plants and the subsequent conversion into organically bound tritium (OBT) strongly depends on the plant characteristics, seasons, and meteorological conditions, which have a large variability. The present study presents an overview of the relevant experimental data for the short term exposure, including the unpublished information, also. Plenty of experimental data is provided for wheat, rice, and soybean and some for potato, bean, cherry tomato, radish, cabbage, and tangerine as well. Tritiated water (HTO) uptake by plants during the daytime and nighttime has an important role in further OBT synthesis. OBT formation in crops depends on the development stage, length, and condition of exposure. OBT translocation to the edible plant parts differs between the crops analyzed. OBT formation during the nighttime is comparable with that during the daytime. The present study is a preliminary step for the development of a robust model of crop contamination after an HTO accidental release. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. The use of tracer techniques to measure water flow rates in steam turbines

    International Nuclear Information System (INIS)

    Whitfield, O.J.; Blaylock, G.; Gale, R.W.

    1979-01-01

    Radioactive and chemical tracers offer some unique advantages in detailed flow measurement on steam turbine plant. A series of experiments on a nuclear power station are reported where tracers successfully measured water flow rates and the initial steam moisture with an accuracy suitable for performance and commissioning tests. Both radioactive and chemical tracer methods produced identical results. Straightforward practical procedures were evolved that ensured repeatable accuracy and in addition a quantitative method of detecting heater leaks on load was established. (author)

  8. Seasonal and global behavior of water vapor in the Mars atmosphere: Complete global results of the Viking atmospheric water detector experiment

    International Nuclear Information System (INIS)

    Jakosky, B.M.; Farmer, C.B.

    1982-01-01

    The water vapor content of the Mars atmosphere was measured from the Viking Orbiter Mars Atmospheric Water Detectors (MAWD) for a period of more than 1 Martian year, from June 1976 through April 1979. Results are presented in the form of global maps of column abundance for 24 periods throughout each Mars year. The data reduction incorporates spatial and seasonal variations in surface pressure and supplements earlier published versions of less complete data

  9. Exobiological implications of dust aggregation in planetary atmospheres: An experiment for the gas-grain simulation facility

    Science.gov (United States)

    Huntington, J. L.; Schwartz, D. E.; Marshall, J. R.

    1991-01-01

    The Gas-Grain Simulation Facility (GGSF) will provide a microgravity environment where undesirable environmental effects are reduced, and thus, experiments involving interactions between small particles and grains can be more suitably performed. Slated for flight aboard the Shuttle in 1992, the ESA glovebox will serve as a scientific and technological testbed for GGSF exobiology experiments as well as generating some basic scientific data. Initial glovebox experiments will test a method of generating a stable, mono-dispersed cloud of fine particles using a vibrating sprinkler system. In the absence of gravity and atmospheric turbulence, it will be possible to determine the influence of interparticle forces in controlling the rate and mode of aggregation. The experimental chamber can be purged of suspended matter to enable multiple repetitions of the experiments. Of particular interest will be the number of particles per unit volume of the chamber, because it is suspected that aggregation will occur extremely rapidly if the number exceeds a critical value. All aggregation events will be recorded on high-resolution video film. Changes in the experimental procedure as a result of surprise events will be accompanied by real-time interaction with the mission specialist during the Shuttle flight.

  10. An experience in Montenegro with atmospheric pollution by means of lichens

    International Nuclear Information System (INIS)

    Jovanovic, S.

    2000-01-01

    The very first study of the atmospheric pollution by means of bioindicators in the region of Montenegro was performed in 1992-93. The study, supported by the Commission of the European Union, was focused to the impact of an aluminium smelter plant to the air pollution in its surroundings. The plant (KAP) is situated 10 km to the south of Podgorica (capital of Montenegro) and produces some 100,000 tons of cast aluminium per year, using French (Pechine) technology. The technological process contributes in several manners to the atmospheric pollution. We investigated an area up to 50 km distances from the plant. Epiphytic lichens (Hypogymnia caperata) were collected from the tree bark 2 m above the ground. In the near vicinity of the plant no epiphytic lichens could have been found (died out due to high pollution levels). Instead, the more resistant lithophytic varieties (Lecanora expallens) were collected therein. Samples of wild grasses and pine needles were taken at the same spots, so as to compare the three indicators. We further found 5-10 times higher pollutant accumulation factors in lichens than in grasses or pine needles, emphasising thus the monitoring sensitivity of the lichens. Soil samples were also taken at the spots and analysed, but no impact factors for the soil were calculated. Samples were analysed by means of the k 0 -method of neutron activation analysis at 'Pierre Sue' Laboratory, Nuclear Research Centre, Saclay/Paris, France. Three types of analyses were made: (i) with short (matter of a few minutes) irradiations at the reactor ORPHEE , followed by analysing the short lived nuclides; (ii) with long (matter of hours) irradiations at the reactor OSIRIS, followed by analysing the long lived nuclides and occasionally - when necessary - (iii) epithermal analyses, in order to suppress the induced activities of certain matrix elements (e.g.Na) and obtain better sensitivity for the other elements. The following elements were determined down to

  11. Comparing the weight method and the use of the tracer Uranine for assessing pesticide drift on soils

    Science.gov (United States)

    Garcia-Santos, G.; Scheiben, D.; Leuenberger, F.; Binder, C. R.

    2009-04-01

    Drift from pesticide backpack-spraying is of major importance in the highlands of Colombia, where more than 20% be drifted by wind effects. This study assesses the usefulness of the weight method and the use of the tracer Uranine for assessing pesticide drift distribution on soils. The weight method has been used in developing countries and consists of weighing previously dried papers, installed close to the soil surface, before and after spraying a known amount of water. Relative humidity, temperature, direction and speed of the wind were monitored during the experiments. The tracer Uranine is often used for groundwater studies. Uranine was added to the water and sprayed by the farmer in the same way he would spray any pesticide mixture. The same papers used in the previous method were stored after the spraying and weighing. The tracer was extracted in water and analyzed using a fluorescent spectrometer. The advantage of Uranine over other tracers is its easy extraction with water and low detectable concentration. No solvents are required for the extraction. The experiments were performed during two months in the wet season in the region of Vereda la Hoya, Boyaca, Colombia at an altitude of 2800 m a.s.l., from September to October. Each experiment lasted about 30 min. The fast-changing meteorological conditions in the region affected the success of the weight method. The paper's weight was very sensitive to atmospheric high relative humidity and different evaporative conditions in grass and bare ground. Location of the blanks was essential and had to represent each of the different experimental evaporative conditions. Although the method was easy to implement, we consider that it is not appropriate for areas characterized by high evapotranspiration rates, and fast-changing climatic conditions as found in the Colombian highlands above 2800 m a.s.l. Whereas Uranine was not sensitive to different evapotranspiration rates nor fast changing climatic conditions, this

  12. Medium-Range Dispersion Experiments Downwind from a Shoreline in Near Neutral Conditions

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Lyck, E.

    1980-01-01

    Five atmospheric dispersion experiments, all assigned Pasquill stability class D, were performed at Risø National Laboratory. The tracer sulphurhexafluoride was released at a height of 60 m from the Risø meteorological tower, situated on a peninsula in the Roskilde Fjord, Denmark, and was sampled...

  13. Airborne spectral measurements of surface-atmosphere anisotropy during the SCAR-A, Kuwait oil fire, and TARFOX experiments

    Science.gov (United States)

    Soulen, Peter F.; King, Michael D.; Tsay, Si-Chee; Arnold, G. Thomas; Li, Jason Y.

    2000-04-01

    During the SCAR-A, Kuwait Oil Fire Smoke Experiment, and TARFOX deployments, angular distributions of spectral reflectance for various surfaces were measured using the scanning Cloud Absorption Radiometer (CAR) mounted on the nose of the University of Washington C-131A research aircraft. The CAR contains 13 narrowband spectral channels between 0.47 and 2.3 μm with a 190° scan aperture (5° before zenith to 5° past nadir) and 1° instantaneous field of view. The bidirectional reflectance is obtained by flying a clockwise circular orbit above the surface, resulting in a ground track approximately 3 km in diameter within about 2 min. Spectral bidirectional reflectances of four surfaces are presented: the Great Dismal Swamp in Virginia with overlying haze layer, the Saudi Arabian Desert and the Persian Gulf in the Middle East, and the Atlantic Ocean measured east of Richmond, Virginia. Although the CAR measurements are contaminated by atmospheric effects, results show distinct spectral characteristics for various types of surface-atmosphere systems, including hot spots, limb brightening and darkening, and Sun glint. In addition, the hemispherical albedo of each surface-atmosphere system is calculated directly by integrating over all high angular-resolution CAR measurements for each spectral channel. Comparing the nadir reflectance with the overall hemispherical albedo of each surface, we find that using nadir reflectances as a surrogate for hemispherical albedo can cause albedos to be underestimated by as much as 95% and overestimated by up to 160%, depending on the type of surface and solar zenith angle.

  14. Study of cation diffusion in Zn O using 65Zn as radioactive tracer

    International Nuclear Information System (INIS)

    Ferraz, Wilmar B.; Correa, Ricardo F.; Nogueira, Maria A.N.; Ramos, Marcelo; Sabioni, Antonio C.S.

    2000-01-01

    Zinc self-diffusion coefficient were measured in polycrystalline Zn O of high purity (99,999%) prepared by conventional sintering at 1393 deg C, 4 h, in oxygen atmosphere. The Zn O samples had high density (>99% of the theoretical density) and grain size of 20 μm. These samples were resintered for 72 h at 1400 deg C in order to increase the grain-size higher than 50 μ m. Samples of 15 x 15 x 2 mm 3 were polished with diamond paste, and pre-annealed under the same conditions of temperature and atmosphere of the diffusion annealing. A thin film of 65 Zn - radioactive tracer - applied to the polished surface was oxidized in oxygen atmosphere for a short time before diffusion annealing. The diffusion experiments were performed between 1002 and 1201 deg C in oxygen atmosphere. The 65 Zn diffusion profiles were measured by sectioning in conjunction with residual-activity measurements. The results of the determination of the zinc in Zn O diffusion coefficients in function of temperature are presented and a comparison of these results obtained by the two radioactive method is showed. (author)

  15. Radiochemical tracers in marine biology

    International Nuclear Information System (INIS)

    Petrocelli, S.R.; Anderson, J.W.; Neff, J.M.

    1977-01-01

    Tracers have been used in a great variety of experimentation. More recently, labeled materials have been applied in marine biological research. Some of the existing tracer techniques have been utilized directly, while others have been modified to suit the specific needs of marine biologists. This chapter describes some of the uses of tracers in marine biological research. It also mentions the problems encountered as well as offering possible solutions and discusses further applications of these techniques. Only pertinent references are cited and additional information may be obtained by consulting these references. Due to their relative ease of maintenance, freshwater species are also utilized in studies which involve radiotracer techniques. Since most of these techniques e directly applicable to marine species, some of these studies will also be included

  16. Radioisotope tracer applications in industry

    International Nuclear Information System (INIS)

    Rao, S.M.

    1987-01-01

    Radioisotope tracers have many advantages in industrial trouble-shooting and studies on process kinetics. The applications are mainly of two types: one leading to qualitative (Yes or No type) information and the other to quantitative characterisation of flow processes through mass balance considerations and flow models. ''Yes or No'' type methods are mainly used for leakage and blockage locations in pipelines and in other industrial systems and also for location of water seepage zones in oil wells. Flow measurements in pipelines and mercury inventory in electrolytic cells are good examples of tracer methods using the mass balance approach. Axial dispersion model and Tanks-in-Series model are the two basic flow models commonly used with tracer methods for the characterisation of kinetic processes. Examples include studies on flow processes in sugar crystallisers as well as in a precalcinator in a cement plant. (author). 18 figs

  17. Journal: A Review of Some Tracer-Test Design Equations for ...

    Science.gov (United States)

    Determination of necessary tracer mass, initial sample-collection time, and subsequent sample-collection frequency are the three most difficult aspects to estimate for a proposed tracer test prior to conducting the tracer test. To facilitate tracer-mass estimation, 33 mass-estimation equations are reviewed here, 32 of which were evaluated using previously published tracer-test design examination parameters. Comparison of the results produced a wide range of estimated tracer mass, but no means is available by which one equation may be reasonably selected over the others. Each equation produces a simple approximation for tracer mass. Most of the equations are based primarily on estimates or measurements of discharge, transport distance, and suspected transport times. Although the basic field parameters commonly employed are appropriate for estimating tracer mass, the 33 equations are problematic in that they were all probably based on the original developers' experience in a particular field area and not necessarily on measured hydraulic parameters or solute-transport theory. Suggested sampling frequencies are typically based primarily on probable transport distance, but with little regard to expected travel times. This too is problematic in that tends to result in false negatives or data aliasing. Simulations from the recently developed efficient hydrologic tracer-test design methodology (EHTD) were compared with those obtained from 32 of the 33 published tracer-

  18. Development of activable tracers for application in secondary recovering in petroleum reservoirs

    International Nuclear Information System (INIS)

    Martins, Polyana Fabricia Fernandes; Moreira, Rubens Martins . Servico de Meio Ambiente e Tecnicas Nucleares.

    2007-01-01

    Nuclear methods are instrumental in describing detailed flow patterns and other features of oil reservoirs that are unattainable to other methods. Tracer studies in oil fields are performed in a net of injection and producing wells. Thus, the use of only one tracer species would not discriminate the contributions of distinct injection wells to the output of a given production well. Hence, a multi-tracer experiment is required, and the use of activable tracers, capable of being measured by neutron activation analysis (NAA) is here proposed. As additional tracer choices lanthanum (La) and europium (Eu) were chosen from the rare earth series due to their large neutron cross sections and general availability. In order to decrease losses to the oil phase and the retardation of the tracer relatively to the aqueous phase, these elements were complexed with organic chelating ligands: the polyaminocarboxylic acids EDTA, DTPA and DOTA. Infrared spectrometry was used to check complexation. In order to check the partition of the tracer between the aqueous and organic phases, tests were carried stirring the two phases together and measuring the tracer concentrations in the aqueous phase; the partition coefficient (Kao) was then calculated for all the combinations of the two lanthanides and the three ligands. Tests in which the tracer was continuously pumped through reservoir rock samples were also carried out using tritiated water as a reference tracer and the complexed lanthanides. (author)

  19. A modified surface-resistance approach for representing bare-soil evaporation: wind tunnel experiments under various atmospheric conditions

    International Nuclear Information System (INIS)

    Yamanaka, T.; Takeda, A.; Sugita, F.

    1997-01-01

    A physically based (i.e., nonempirical) representation of surface-moisture availability is proposed, and its applicability is investigated. This method is based on the surface-resistance approaches, and it uses the depth of evaporating surface rather than the water content of the surface soil as the determining factor of surface-moisture availability. A simple energy-balance model including this representation is developed and tested against wind tunnel experiments under various atmospheric conditions. This model can estimate not only the latent heat flux but also the depth of the evaporating surface simultaneously by solving the inverse problem of energy balance at both the soil surface and the evaporating surface. It was found that the depth of the evaporating surface and the latent heat flux estimated by the model agreed well with those observed. The agreements were commonly found out under different atmospheric conditions. The only limitation of this representation is that it is not valid under conditions of drastic change in the radiation input, owing to the influence of transient phase transition of water in the dry surface layer. The main advantage of the approach proposed is that it can determine the surface moisture availability on the basis of the basic properties of soils instead of empirical fitting, although further investigations on its practical use are needed

  20. The New Horizons Radio Science Experiment: Performance and Measurements of Pluto's Atmospheric Structure, Surface Pressure, and Surface Temperature

    Science.gov (United States)

    Linscott, I.; Hinson, D. P.; Bird, M. K.; Stern, A.; Weaver, H. A., Jr.; Olkin, C.; Young, L. A.; Ennico Smith, K.

    2015-12-01

    The New Horizons (NH) spacecraft payload contained the Radio Science Experiment (REX) for determining key characteristics of Pluto and Charon during the July 14, 2015, flyby of the Pluto/Charon system. The REX flight equipment augments the NH X-band radio transceiver by providing a high precision, narrow band recording of high power uplink transmissions from Earth stations, as well as a record of broadband radiometric power. This presentation will review the performance and initial results of two high- priority observations. First, REX received two pair of 20-kW signals, one pair per polarization, transmitted from the DSN at 4.2-cm wavelength during a diametric radio occultation by Pluto. REX recorded these uplink signals and determined precise measurement of the surface pressure, the temperature structure of the lower atmosphere, and the surface radius of Pluto. The ingress portion of one polarization was played back from the spacecraft in July and processed to obtain the pressure and temperature structure of Pluto's atmosphere. Second, REX measured the thermal emission from Pluto at 4.2- cm wavelength during two linear scans across the disk at close range when both the dayside and the night side are visible. Both scans extend from limb to limb with a resolution of one-tenth Pluto's disk and temperature resolution of 0.1 K. Occultation and radiometric temperature results presented here will encompass additional data scheduled for playback in September.

  1. Characterization of a managed aquifer recharge system using multiple tracers.

    Science.gov (United States)

    Moeck, Christian; Radny, Dirk; Popp, Andrea; Brennwald, Matthias; Stoll, Sebastian; Auckenthaler, Adrian; Berg, Michael; Schirmer, Mario

    2017-12-31

    Knowledge about the residence times of artificially infiltrated water into an aquifer and the resulting flow paths is essential to developing groundwater-management schemes. To obtain this knowledge, a variety of tracers can be used to study residence times and gain information about subsurface processes. Although a variety of tracers exists, their interpretation can differ considerably due to subsurface heterogeneity, underlying assumptions, and sampling and analysis limitations. The current study systematically assesses information gained from seven different tracers during a pumping experiment at a site where drinking water is extracted from an aquifer close to contaminated areas and where groundwater is artificially recharged by infiltrating surface water. We demonstrate that the groundwater residence times estimated using dye and heat tracers are comparable when the thermal retardation for the heat tracer is considered. Furthermore, major ions, acesulfame, and stable isotopes (δ 2 H and δ 18 O) show that mixing of infiltrated water and groundwater coming from the regional flow path occurred and a vertical stratification of the flow system exist. Based on the concentration patterns of dissolved gases (He, Ar, Kr, N 2 , and O 2 ) and chlorinated solvents (e.g., tetrachloroethene), three temporal phases are observed in the ratio between infiltrated water and regional groundwater during the pumping experiment. Variability in this ratio is significantly related to changes in the pumping and infiltration rates. During constant pumping rates, more infiltrated water was extracted, which led to a higher dilution of the regional groundwater. An infiltration interruption caused however, the ratio to change and more regional groundwater is extracted, which led to an increase in all concentrations. The obtained results are discussed for each tracer considered and its strengths and limitations are illustrated. Overall, it is demonstrated that aquifer heterogeneity and

  2. Assessing preferential flow by simultaneously injecting nanoparticle and chemical tracers

    KAUST Repository

    Subramanian, S. K.; Li, Yan; Cathles, L. M.

    2013-01-01

    The exact manner in which preferential (e.g., much faster than average) flow occurs in the subsurface through small fractures or permeable connected pathways of other kinds is important to many processes but is difficult to determine, because most chemical tracers diffuse quickly enough from small flow channels that they appear to move more uniformly through the rock than they actually do. We show how preferential flow can be assessed by injecting 2 to 5 nm carbon particles (C-Dots) and an inert KBr chemical tracer at different flow rates into a permeable core channel that is surrounded by a less permeable matrix in laboratory apparatus of three different designs. When the KBr tracer has a long enough transit through the system to diffuse into the matrix, but the C-Dot tracer does not, the C-Dot tracer arrives first and the KBr tracer later, and the separation measures the degree of preferential flow. Tracer sequestration in the matrix can be estimated with a Peclet number, and this is useful for experiment design. A model is used to determine the best fitting core and matrix dispersion parameters and refine estimates of the core and matrix porosities. Almost the same parameter values explain all experiments. The methods demonstrated in the laboratory can be applied to field tests. If nanoparticles can be designed that do not stick while flowing through the subsurface, the methods presented here could be used to determine the degree of fracture control in natural environments, and this capability would have very wide ranging value and applicability.

  3. TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data

    Science.gov (United States)

    Jurgens, Bryant C.; Böhlke, J.K.; Eberts, Sandra M.

    2012-01-01

    TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of hydrodynamic dispersion or mixing within the aquifer, well bore, or discharge area. Five primary LPMs are included in the workbook: piston-flow model (PFM), exponential mixing model (EMM), exponential piston-flow model (EPM), partial exponential model (PEM), and dispersion model (DM). Binary mixing models (BMM) can be created by combining primary LPMs in various combinations. Travel time through the unsaturated zone can be included as an additional parameter. TracerLPM also allows users to enter age distributions determined from other methods, such as particle tracking results from numerical groundwater-flow models or from other LPMs not included in this program. Tracers of both young groundwater (anthropogenic atmospheric gases and isotopic substances indicating post-1940s recharge) and much older groundwater (carbon-14 and helium-4) can be interpreted simultaneously so that estimates of the groundwater age distribution for samples with a wide range of ages can be constrained. TracerLPM is organized to permit a comprehensive interpretive approach consisting of hydrogeologic conceptualization, visual examination of data and models, and best-fit parameter estimation. Groundwater age distributions can be evaluated by comparing measured and modeled tracer concentrations in two ways: (1) multiple tracers analyzed simultaneously can be evaluated against each other for concordance with modeled concentrations (tracer-tracer application) or (2) tracer time-series data can be evaluated for concordance with modeled trends (tracer-time application). Groundwater-age estimates can also be obtained for samples with a single tracer measurement at one

  4. Pharmaceuticals as Groundwater Tracers - Applications and Limitations

    Science.gov (United States)

    Scheytt, T. J.; Mersmann, P.; Heberer, T.

    2003-12-01

    Pharmaceutically active substances and metabolites are found at concentrations up to the microgram/L-level in groundwater samples from the Berlin (Germany) area and from several other places world wide. Among the compounds detected in groundwater are clofibric acid, propyphenazone, diclofenac, ibuprofen, and carbamazepine. Clofibric acid, the active metabolite of clofibrate and etofibrate (blood lipid regulators) is detected in groundwater at maximum concentrations of 7300 ng/L. Among the most important input paths of drugs are excretion and disposal into the sewage system. Groundwater contamination is likely to be due to leaky sewage systems, influent streams, bank filtration, and irrigation with effluent water from sewage treatment plants. There are no known natural sources of the above mentioned pharmaceuticals. The use of pharmaceuticals as tracers may include: (a) Quantification of infiltration from underground septic tanks (b) Detection of leaky sewage systems / leaky sewage pipes (c) Estimation of the effectiveness of sewage treatment plants (d) Identification of transport pathways of other organic compounds (e) Quantification of surface water / groundwater interaction (f) Characterization of the biodegradation potential. The use of pharmaceuticals as tracers is limited by variations in input. These variations depend on the amount of drugs prescribed and used in the study area, the social structure of the community, the amount of hospital discharge, and temporal concentration variations. Furthermore, the analysis of trace amounts of pharmaceuticals is sophisticated and expensive and may therefore limit the applicability of pharmaceuticals as tracers. Finally, the transport and degradation behavior of pharmaceuticals is not fully understood. Preliminary experiments in the laboratory were conducted using sediment material and groundwater from the Berlin area to evaluate the transport and sorption behavior of selected drugs. Results of the column experiments

  5. The effect of filtration on radon daughter atmospheres: Laboratory and field experiments

    International Nuclear Information System (INIS)

    Jonassen, N.; Jensen, B.

    1987-01-01

    Airborne radon daughters may be removed from the air by internal filtration using mechanical or electrofilters. The effect of the filtration may be evaluated in absolute measure by the decrease in the potential alpha energy concentration (or equivalent equilibrium concentration) or relatively by the decrease in the equilibrium factor. The filtration, however, may also change the distribution of airborne radon daughter activity between the unattached and the aerosol-attached state in a way to increase the radiological dose corresponding to a given potential alpha energy concentration. The paper describes a series of laboratory and field experiments which indicate that it is possible by the use of household electrofilters with filtration rates of 2-3 h -1 to lower the radon daughter concentrations to about 20 -30 % and the average radiological dose to about 50-60 % of the value in unfiltered air

  6. Analysis of infiltration through mill tailings using a bromide tracer

    International Nuclear Information System (INIS)

    Lewis, G.J.; Stephens, D.B.

    1985-01-01

    Infiltration of precipitation into tailings impoundments as a means of recharge to underlying materials is often considered insignificant, particularly in arid and semi-arid environments. A series of experiments was performed to investigate the behavior of infiltrated precipitation into tailing soils, by the use of a bromide tracer. A bromide tracer was applied to the surface of columns driven into the tailings to monitor downward advancement of tracer-laden water. Controlled laboratory experiments on the behavior of the bromide tracer under varying precipitation events and initial soil moisture contents were also conducted. Results indicate that a definite downward migration of infiltrated precipitation occurs, particularly with large magnitude precipitation events, and that, eventually, some fraction of the infiltrated precipitation may continue downward below the zone affected by evaporation. The use of an artificially applied bromide tracer to monitor depth of infiltration of precipitation is a simple, safe technique that can provide valuable information for long-term tailings management strategies at low cost

  7. Analysis of some laboratory tracer runs in natural fissures

    International Nuclear Information System (INIS)

    Moreno, L.; Neretnieks, I.

    1984-01-01

    Tracer tests in natural fissures performed in the laboratory are analysed by means of fitting two different models. In the experiments, sorbing and non-sorbing tracers were injected into a natural fissure running parallel to the axis of a drill core. The models take into account advection, diffusion into the rock matrix, sorption onto the rock surface and dispersion. For the last mechanism, one of the models considers hydrodynamic dispersion while the other model assumes channeling dispersion. The models take into account time delays in the inlet and outlet channels. The dispersion characteristics and water residence time were determined from the experiments with non-sorbing tracers. Surface and volume sorption coefficients and data on diffusion into the rock matrix were determined for the sorbing tracers. The results are compared with values independently determined in the laboratory. Good agreement was obtained using either model. When these models are used for prediction of tracer transport over larger distances, the results will depend on the model. The model with channeling dispersion will show a greater dispersion than the model with hydrodynamic dispersion. (author)

  8. The atmospheric impacts of monoterpene ozonolysis on global stabilised Criegee intermediate budgets and SO2 oxidation: experiment, theory and modelling

    Directory of Open Access Journals (Sweden)

    M. J. Newland

    2018-05-01

    Full Text Available The gas-phase reaction of alkenes with ozone is known to produce stabilised Criegee intermediates (SCIs. These biradical/zwitterionic species have the potential to act as atmospheric oxidants for trace pollutants such as SO2, enhancing the formation of sulfate aerosol with impacts on air quality and health, radiative transfer and climate. However, the importance of this chemistry is uncertain as a consequence of limited understanding of the abundance and atmospheric fate of SCIs. In this work we apply experimental, theoretical and numerical modelling methods to quantify the atmospheric impacts, abundance and fate of the structurally diverse SCIs derived from the ozonolysis of monoterpenes, the second most abundant group of unsaturated hydrocarbons in the atmosphere. We have investigated the removal of SO2 by SCIs formed from the ozonolysis of three atmospherically important monoterpenes (α-pinene, β-pinene and limonene in the presence of varying amounts of water vapour in large-scale simulation chamber experiments that are representative of boundary layer conditions. The SO2 removal displays a clear dependence on water vapour concentration, but this dependence is not linear across the range of [H2O] explored. At low [H2O] a strong dependence of SO2 removal on [H2O] is observed, while at higher [H2O] this dependence becomes much weaker. This is interpreted as being caused by the production of a variety of structurally (and hence chemically different SCIs in each of the systems studied, which displayed different rates of reaction with water and of unimolecular rearrangement or decomposition. The determined rate constants, k(SCI+H2O, for those SCIs that react primarily with H2O range from 4 to 310  ×  10−15 cm3 s−1. For those SCIs that predominantly react unimolecularly, determined rates range from 130 to 240 s−1. These values are in line with previous results for the (analogous stereo-specific SCI system of syn-/anti-CH3

  9. The atmospheric impacts of monoterpene ozonolysis on global stabilised Criegee intermediate budgets and SO2 oxidation: experiment, theory and modelling

    Science.gov (United States)

    Newland, Mike J.; Rickard, Andrew R.; Sherwen, Tomás; Evans, Mathew J.; Vereecken, Luc; Muñoz, Amalia; Ródenas, Milagros; Bloss, William J.

    2018-05-01

    The gas-phase reaction of alkenes with ozone is known to produce stabilised Criegee intermediates (SCIs). These biradical/zwitterionic species have the potential to act as atmospheric oxidants for trace pollutants such as SO2, enhancing the formation of sulfate aerosol with impacts on air quality and health, radiative transfer and climate. However, the importance of this chemistry is uncertain as a consequence of limited understanding of the abundance and atmospheric fate of SCIs. In this work we apply experimental, theoretical and numerical modelling methods to quantify the atmospheric impacts, abundance and fate of the structurally diverse SCIs derived from the ozonolysis of monoterpenes, the second most abundant group of unsaturated hydrocarbons in the atmosphere. We have investigated the removal of SO2 by SCIs formed from the ozonolysis of three atmospherically important monoterpenes (α-pinene, β-pinene and limonene) in the presence of varying amounts of water vapour in large-scale simulation chamber experiments that are representative of boundary layer conditions. The SO2 removal displays a clear dependence on water vapour concentration, but this dependence is not linear across the range of [H2O] explored. At low [H2O] a strong dependence of SO2 removal on [H2O] is observed, while at higher [H2O] this dependence becomes much weaker. This is interpreted as being caused by the production of a variety of structurally (and hence chemically) different SCIs in each of the systems studied, which displayed different rates of reaction with water and of unimolecular rearrangement or decomposition. The determined rate constants, k(SCI+H2O), for those SCIs that react primarily with H2O range from 4 to 310 × 10-15 cm3 s-1. For those SCIs that predominantly react unimolecularly, determined rates range from 130 to 240 s-1. These values are in line with previous results for the (analogous) stereo-specific SCI system of syn-/anti-CH3CHOO. The experimental results are

  10. The NPE gas tracer test and the development of on-site inspection techniques

    International Nuclear Information System (INIS)

    Carrigan, C.; Heinle, R.; Zucca, J.J.

    1995-01-01

    Tracer gases emplaced in or near the detonation cavity of the 1-kiloton Non-Proliferation Event required 1.5 and 13.5 months for sulfur hexaflouride and helium-3, respectively, to reach the surface of Rainier Mesa from an emplacement depth of 400 meters. The sites that first produced tracer gases are those located in known faults and fractures. Numerical modeling suggests that transport to the surface is accomplished within this time frame through atmospheric pumping along high permeability pathways such as fractures. The difference in travel time between the two tracers is due to differences in gas diffusivity and can also be explained by our numerical modeling. (author)

  11. The Turbopause experiment: atmospheric stability and turbulent structure spanning the turbopause altitude

    Directory of Open Access Journals (Sweden)

    G. A. Lehmacher

    2011-12-01

    Full Text Available Very few sequences of high resolution wind and temperature measurements in the lower thermosphere are available in the literature, which makes it difficult to verify the simulation results of models that would provide better understanding of the complex dynamics of the region. To address this problem the Turbopause experiment used four rockets launched over a period of approximately two hours from Poker Flat Research Range, Alaska (64° N, 147° W on the night of 17–18 February 2009. All four rocket payloads released trimethyl aluminum trails for neutral wind and turbulence measurements, and two of the rockets carried ionization gauges and fixed-bias Langmuir probes measuring neutral and electron densities, small-scale fluctuations and neutral temperatures. Two lidars monitored temperature structure and sodium densities. The observations were made under quiet geomagnetic conditions and show persistence in the wind magnitudes and shears throughout the observing period while being modulated by inertia-gravity waves. High resolution temperature profiles show the winter polar mesosphere and lower thermosphere in a state of relatively low stability with several quasi-adiabatic layers between 74 and 103 km. Temperature and wind data were combined to calculate Richardson number profiles. Evidence for turbulence comes from simultaneous observations of density fluctuations and downward transport of sodium in a mixed layer near 75 km; the observation of turbulent fluctuations and energy dissipation from 87–90 km; and fast and irregular trail expansion at 90–93 km, and especially between 95 to 103 km. The regions of turbulent trails agree well with regions of quasi-adiabatic temperature gradients. Above 103 km, trail diffusion was mainly laminar; however, unusual features and vortices in the trail diffusion were observed up to 118 km that have not been as prevalent or as clearly evident in earlier trail releases.

  12. Tracers of cancer cells in nuclear oncology

    International Nuclear Information System (INIS)

    Tamgac, F.; Baillet, G.; Moretti, J.L.; Safi, N.; Weinmann, P.; Beco, V. de

    1997-01-01

    Evaluating the extent of disease is important in planning cancer treatment. Different types of tracers are used in vivo to diagnose tumors and these tracers can give supplementary information on the differentiation degree of tumors and response to therapy. (authors)

  13. Structural aspects of the atmospheric aerosol of the Amazon basin

    International Nuclear Information System (INIS)

    Artaxo Netto, P.E.; Orsini, C.M.Q.

    1982-01-01

    The results presented on this paper may be considered as complementary to the ones published on two previous papers about the natural atmospheric aerosol of the Amazon Basin, and the effects, on these physical-chemical systems of the large scale brushfires carried out from time to time on that region. The experiments have been performed in August-September, 1980, simultaneously to the ones of the 'Projeto Queimadas - 1980' promoted by the National Center for Atmospheric Research from the U.S.A.. The new results here in presented are size distribution concentration data as log-probability curves for the detected tracer-elements; from these curves, by introducing a new technique, is was possible to derive the corresponding log-normal curves. These last curves can be used conveniently to characterize the atmospheric aerosol system which is under investigation. (Author) [pt

  14. PIV tracer behavior on propagating shock fronts

    International Nuclear Information System (INIS)

    Glazyrin, Fyodor N; Mursenkova, Irina V; Znamenskaya, Irina A

    2016-01-01

    The present work was aimed at the quantitative particle image velocimetry (PIV) measurement of a velocity field near the front of a propagating shock wave and the study of the dynamics of liquid tracers crossing the shock front. For this goal, a shock tube with a rectangular cross-section (48  ×  24 mm) was used. The flat shock wave with Mach numbers M  =  1.4–2.0 propagating inside the tube channel was studied as well as an expanding shock wave propagating outside the channel with M  =  1.2–1.8 at its main axis. The PIV imaging of the shock fronts was carried out with an aerosol of dioctyl sebacate (DEHS) as tracer particles. The pressures of the gas in front of the shock waves studied ranged from 0.013 Mpa to 0.1 MPa in the series of experiments. The processed PIV data, compared to the 1D normal shock theory, yielded consistent values of wake velocity immediately behind the plain shock wave. Special attention was paid to the blurring of the velocity jump on the shock front due to the inertial particle lag and peculiarities of the PIV technique. A numerical algorithm was developed for analysis and correction of the PIV data on the shock fronts, based on equations of particle-flow interaction. By application of this algorithm, the effective particle diameter of the DEHS aerosol tracers was estimated as 1.03  ±  0.12 μm. A number of different formulations for particle drag were tested with this algorithm, with varying success. The results show consistency with previously reported experimental data obtained for cases of stationary shock waves. (paper)

  15. Application of open-path Fourier transform infrared spectroscopy for atmospheric monitoring of a CO2 back-production experiment at the Ketzin pilot site (Germany).

    Science.gov (United States)

    Sauer, Uta; Borsdorf, H; Dietrich, P; Liebscher, A; Möller, I; Martens, S; Möller, F; Schlömer, S; Schütze, C

    2018-02-03

    During a controlled "back-production experiment" in October 2014 at the Ketzin pilot site, formerly injected CO 2 was retrieved from the storage formation and directly released to the atmosphere via a vent-off stack. Open-path Fourier transform infrared (OP FTIR) spectrometers, on-site meteorological parameter acquisition systems, and distributed CO 2 point sensors monitored gas dispersion processes in the near-surface part of the atmospheric boundary layer. The test site provides a complex and challenging mosaic-like surface setting for atmospheric monitoring which can also be found at other storage sites. The main aims of the atmospheric monitoring of this experiment were (1) to quantify temporal and spatial variations in atmospheric CO 2 concentrations around the emitting vent-off stack and (2) to test if and how atmospheric monitoring can cope with typical environmental and operational challenges. A low environmental risk was encountered during the whole CO 2 back-production experiment. The study confirms that turbulent wind conditions favor atmospheric mixing processes and are responsible for rapid dilution of the released CO 2 leading to decreased detectability at all sensors. In contrast, calm and extremely stable wind conditions (especially occurring during the night) caused an accumulation of gases in the near-ground atmospheric layer with the highest amplitudes in measured gas concentration. As an important benefit of OP FTIR spectroscopic measurements and their ability to detect multiple gas species simultaneously, emission sources could be identified to a much higher certainty. Moreover, even simulation models using simplified assumptions help to find suitable monitoring network designs and support data analysis for certain wind conditions in such a complex environment.

  16. A Comparison between Predicted and Observed Atmospheric States and their Effects on Infrasonic Source Time Function Inversion at Source Physics Experiment 6

    Science.gov (United States)

    Aur, K. A.; Poppeliers, C.; Preston, L. A.

    2017-12-01

    The Source Physics Experiment (SPE) consists of a series of underground chemical explosions at the Nevada National Security Site (NNSS) designed to gain an improved understanding of the generation and propagation of physical signals in the near and far field. Characterizing the acoustic and infrasound source mechanism from underground explosions is of great importance to underground explosion monitoring. To this end we perform full waveform source inversion of infrasound data collected from the SPE-6 experiment at distances from 300 m to 6 km and frequencies up to 20 Hz. Our method requires estimating the state of the atmosphere at the time of each experiment, computing Green's functions through these atmospheric models, and subsequently inverting the observed data in the frequency domain to obtain a source time function. To estimate the state of the atmosphere at the time of the experiment, we utilize the Weather Research and Forecasting - Data Assimilation (WRF-DA) modeling system to derive a unified atmospheric state model by combining Global Energy and Water Cycle Experiment (GEWEX) Continental-scale International Project (GCIP) data and locally obtained sonde and surface weather observations collected at the time of the experiment. We synthesize Green's functions through these atmospheric models using Sandia's moving media acoustic propagation simulation suite (TDAAPS). These models include 3-D variations in topography, temperature, pressure, and wind. We compare inversion results using the atmospheric models derived from the unified weather models versus previous modeling results and discuss how these differences affect computed source waveforms with respect to observed waveforms at various distances. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear

  17. Observations of peroxyacetyl nitrate (PAN) in the upper troposphere by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)

    Science.gov (United States)

    Tereszchuk, K. A.; Moore, D. P.; Harrison, J. J.; Boone, C. D.; Park, M.; Remedios, J. J.; Randel, W. J.; Bernath, P. F.

    2013-01-01

    Peroxyacetyl nitrate (CH3CO·O2NO2, abbreviated as PAN) is a trace molecular species present in the troposphere and lower stratosphere due primarily to pollution from fuel combustion and the pyrogenic outflows from biomass burning. In the lower troposphere, PAN has a relatively short life-time and is principally destroyed within a few hours through thermolysis, but it can act as a reservoir and carrier of NOx in the colder temperatures of the upper troposphere where UV photolysis becomes the dominant loss mechanism. Pyroconvective updrafts from large biomass burning events can inject PAN into the upper troposphere and lower stratosphere (UTLS), providing a means for the long-range transport of NOx. Given the extended lifetimes at these higher altitudes, PAN is readily detectable via satellite remote sensing. A new PAN data product is now available for the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) Version 3.0 data set. We report measurements of PAN in Boreal biomass burning plumes recorded during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) campaign. The retrieval method employed and errors analysis are described in full detail. The retrieved volume mixing ratio (VMR) profiles are compared to coincident measurements made by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument on the European Space Agency (ESA) ENVIronmental SATellite (ENVISAT). Three ACE-FTS occultations containing measurements of Boreal biomass burning outflows, recorded during BORTAS, were identified as having coincident measurements with MIPAS. In each case, the MIPAS measurements demonstrated good agreement with the ACE-FTS VMR profiles for PAN. The ACE-FTS PAN data set is used to obtain zonal mean distributions of seasonal averages from ~5 to 20 km. A strong seasonality is clearly observed for PAN concentrations in the global UTLS. Since the

  18. Interwell tracer analyses of a hydraulically fractured granitic geothermal reservoir

    International Nuclear Information System (INIS)

    Tester, J.W.; Potter, R.M.; Bivins, R.L.

    1979-01-01

    Field experiments using fluorescent dye and radioactive tracers (Br 82 and I 131 ) have been employed to characterize a hot, low-matrix permeability, hydraulically-fractured granitic reservoir at depths of 2440 to 2960 m (8000 to 9700 ft). Tracer profiles and residence time distributions have been used to delineate changes in the fracture system, particularly in diagnosing pathological flow patterns and in identifying new injection and production zones. The effectiveness of one- and two-dimensional theoretical dispersion models utilizing single and multiple porous, fractured zones with velocity and formation dependent effects are discussed with respect to actual field data

  19. Atmospherical experiment in Angra I plant for characterizing the effluent transport threw in the atmospheric; Experimento atmosferico no local da Usina Angra I para caracterizar o transporte de efluentes lancados na atmosfera

    Energy Technology Data Exchange (ETDEWEB)

    Silva Lobo, M.A. da [FURNAS, Rio de Janeiro, RJ (Brazil); Kronemberger, B M.E.

    1990-12-31

    Available as short communication only. The Environmental Safety Division of the Nuclear Safety and Fuel Department from FURNAS Electric Station S.A. joint with the National Oceanic and Atmospheric Administration (NOAA), achieved a field experiment for characterizing the atmospheric transport and diffusion in the site complex of Angra I Nuclear Power Plant. The complex topography with the thick vegetation and the neighbour building bring problems for the modelling of the effluent transport and the dispersion. The actual meteorological measure system is automatic and compound with four towers. An intensive atmospheric measure with captive balloon is included, and the collected data shows that the site flux is strongly influenced by the topography and insolation. (C.G.C.). 2 figs.

  20. Development of radioisotope tracer technology and nucleonic control system

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Joon Ha; Lee, Myun Joo; Jung, Sung Hee and others

    1999-04-01

    The purpose of this study is to develop the radioisotope tracer technology, which can be used in solving industrial and environmental problems and basic technology of nuclear control systems that are widely used for automation of industrial plants, and to build a strong tracer group to support the local industries. In relation to the tracer technology, the data acquisition system, the column scanning equipment and the detection pig for a leakage test have been developed. In order to use in analyzing data of tracer experiments, a computer program for the analysis of residence time distribution has been created as well. These results were utilized in developing the tracer technologies, such as the column scanning, the flow measurement using the dilution method, the simultaneous monitoring rotational movement of piston rings and the optimization of a waste water treatment facility, and the technologies were successfully demonstrated in the local industrial. The stripper of RFCC reactor has been examined to find an unwanted structure in it by imminent request from the industry. Related to the development of nucleonic control system, the state of art report on the technology has been written and an equipment for the analysis of asphalt content has been developed. (author)

  1. Spectral analysis for evaluation of myocardial tracers for medical imaging

    International Nuclear Information System (INIS)

    Huesman, Ronald H.; Reutter, Bryan W.; Marshall, Robert C.

    2000-01-01

    Kinetic analysis of dynamic tracer data is performed with the goal of evaluating myocardial radiotracers for cardiac nuclear medicine imaging. Data from experiments utilizing the isolated rabbit heart model are acquired by sampling the venous blood after introduction of a tracer of interest and a reference tracer. We have taken the approach that the kinetics are properly characterized by an impulse response function which describes the difference between the reference molecule (which does not leave the vasculature) and the molecule of interest which is transported across the capillary boundary and is made available to the cell. Using this formalism we can model the appearance of the tracer of interest in the venous output of the heart as a convolution of the appearance of the reference tracer with the impulse response. In this work we parameterize the impulse response function as the sum of a large number of exponential functions whose predetermined decay constants form a spectrum, and each is required only to have a nonnegative coefficient. This approach, called spectral analysis, has the advantage that it allows conventional compartmental analysis without prior knowledge of the number of compartments which the physiology may require or which the data will support

  2. Holdup time measurement by radioactive tracers in pulp production

    International Nuclear Information System (INIS)

    Roetzer, H.; Donhoffer, D.

    1988-12-01

    A batch of pulp was to be labelled before passing two bleaching towers of a pulp plant. Activated glass fibres were used as a tracer, which contained 24-Na with a half-life of 15 hours. It was shown in laboratory tests, that the glass fibres were suitable for transport studies of wood pulp. For use in the tests the fibres were activated and suspended in water. Due to the small diameter of the fibres (2-5 micrometers) this suspension shows physical properties very similar to the pulp. For detection six scintillation probes were mounted at different positions outside the bleaching tower. Radiation protection during the test was very easy due to the low total activity of the tracer material. Residence time distributions for both towers were measured. The successful tracer experiments show, that the method of labelling is suited for investigations of material transport in the pulp and paper industry. 3 figs., 11 refs., 2 tabs. (Author)

  3. the Martian atmospheric boundary layer

    DEFF Research Database (Denmark)

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

    2011-01-01

    . This portion of the atmosphere is extremely important, both scientifically and operationally, because it is the region within which surface lander spacecraft must operate and also determines exchanges of heat, momentum, dust, water, and other tracers between surface and subsurface reservoirs and the free...

  4. The brasimone study (brastud) an investigation of atmospheric dispersion over complex terrain

    International Nuclear Information System (INIS)

    Cagnetti, P.; Ocone, R.; Racalbuto, S.

    1988-01-01

    An investigation of atmospheric dispersion over complex terrain was carried out in September 1984 and in June 1985 at the Brasimone Energy Research Centre (B.E.R.C.). This place, where an experimental nuclear reactor is under construction, is located in the Tuscan-Emilian Appennine range approximately 50 km south of Bologna. The measuring campaigns, based on survey of wind and temperature parameters, tracer (SF 6 ) experiments and tracking of tetroons by radar, were performed with the purpose of assessing the atmospheric dispersion of pollutants under nocturnal drainage flow conditions. The three-dimensional MATHEW/ADPIC model was evaluated with the Brasimone data set and the results obtained are satisfactory

  5. Fifty years of radiochemical tracers

    International Nuclear Information System (INIS)

    Evans, E.A.

    1992-01-01

    During the past 50 years radiochemical tracers, usually in the form of isotopically labelled organic compounds, have been essential tools to further advance our knowledge at the frontiers of a great variety of scientific developments in the life sciences. This plenary lecture reviews necessarily selected highlights in the synthesis and applications of such radiochemical tracers. Included are examples where important advances, made possible by using radiochemicals, have contributed to improving the quality of life on this planet. The principal radioisotopes involved, 14 C, 3 H, 35 S, 32 P, 125 I, are all relatively safe to handle and are commercially available at maximum theoretical specific activity (carrier free). The compounds labeled with these radioisotopes are used in many fields of research which include biosynthesis and biotechnology studies, cell biology, drug metabolism, clinical research and environmental applications, and are briefly reviewed. (author). 55 refs

  6. Tracer techniques in food industry

    International Nuclear Information System (INIS)

    Pertsovskij, E.S.; Sakharov, Eh.V.; Dolinin, V.A.

    1980-01-01

    The appicability of radioactive tracer techniques to process control in food industry are considered. Investigations in the field of food industry carried out using the above method are classified. The 1 class included investigations with preliminary preparation of a radioactive indicator and its following introduction in the system studied. The 2 class includes investigations based on the introduction in the system studied of a non-active indicator which is activated in a neutron flux being in samples selected in or after the process investigated. The 3 class includes studies based on investigations of natural radioactivity of certain nuclides in food stuff. The application of tracer techniques to the above classes of investigations in various fields of food industry and the equipment applied are considered in detail [ru

  7. Applicability of U.S. Army tracer test data to model validation needs of ERDA

    International Nuclear Information System (INIS)

    Shearer, D.L.; Minott, D.H.

    1976-06-01

    This report covers the first phase of an atmospheric dispersion model validation project sponsored by the Energy Research and Development Administration (ERDA). The project will employ dispersion data generated during an extensive series of field tracer experiments that were part of a meteorological research program which was conducted by the U. S. Army Dugway Proving Ground, Utah, from the late 1950's to the early 1970's. The tests were conducted at several locations in the U. S., South America, Germany, and Norway chosen to typify the effects of certain environmental factors on atmospheric dispersion. The purpose of the Phase I work of this project was to identify applicable portions of the Army data, obtain and review that data, and make recommendations for its uses for atmospheric dispersion model validations. This report presents key information in three formats. The first is a tabular listing of the Army dispersion test reports summarizing the test data contained in each report. This listing is presented in six separate tables with each tabular list representing a different topical area that is based on model validation requirements and the nature of the Army data base. The second format for presenting key information is a series of discussions of the Army test information assigned to each of the six topical areas. These discussions relate the extent and quality of the available data, as well as its prospective use for model validation. The third format is a series of synopses for each Army test report

  8. Waves in the middle and upper atmosphere of Mars as seen by the Radio Science Experiment MaRS on Mars Express

    Science.gov (United States)

    Tellmann, S.; Paetzold, M.; Häusler, B.; Hinson, D. P.; Peter, K.; Tyler, G. L.

    2017-12-01

    Atmospheric waves play a crucial role in the Martian atmosphere. They are responsible for the redistribution of momentum, energy and dust and for the coupling of the different atmospheric regions on Mars. Almost all kinds of waves have been observed in the lower atmosphere (e.g. stationary and transient waves, baroclinic waves as well as migrating and non-migrating thermal tides, gravity waves, etc...). Atmospheric waves are also known to exist in the middle atmosphere of Mars ( 70-120 km, e.g. by the SPICAM instrument on Mars Express). In the thermosphere, thermal tides have been observed e.g. by radio occultation or accelerometer measurements on MGS. Recently, the NGIMS instrument on MAVEN reported gravity waves in the thermosphere of Mars. Radio Science profiles from the Mars Express Radio Science experiment MaRS on Mars Express can analyse the temperature, pressure and neutral number density profiles in the lower atmosphere (from a few hundred metres above the surface up to 40-50 km) and electron density profiles in the ionosphere of Mars. Wavelike structures have been detected