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Sample records for case study atmospheric

  1. Effects of Clouds on Cross-Atmospheric Radiative Flux Divergence: Case Studies in Different Cloud Conditions

    NASA Astrophysics Data System (ADS)

    Ghate, V. P.; Miller, M. A.

    2013-12-01

    Clouds have a profound effect on the amount of radiation absorbed across the atmospheric column. The amount of absorption mainly depends on the location and type of the clouds, the albedo of the surface and profile of water vapor mixing ratio in the atmospheric column. In this study we have used the data collected during the deployment of Atmospheric Radiation Measurement (ARM)'s first Mobile Facility (AMF#1) at the island of Graciosa in the North Atlantic and at the Niamey, Niger to assess the impact of different cloud types on the cross-atmospheric radiative flux divergence. The cloud structure was retrieved using the data collected by a vertically pointing w-band cloud radar, a micro-pulse lidar, laser ceilometer among other instruments. The profiles of temperature, moisture and winds were measured by balloon borne radiosondes. The radiation at the surface were measured by broadband radiometers, while the radiation at the top of the atmosphere were measured by the Geostationary Earth Radiation Budget (GERB) radiometers onboard the Meteosat Second Generation (MSG) satellite. Simulations of a 1-dimensional radiative transfer model called as Rapid Radiative Transfer Model (RRTM) having representation of cloud and aerosol properties are made to assess the relative impact of different cloud types and water vapor on spectral bands both in the shortwave and longwave radiation spectrum. Results from four case-studies which had cloud free conditions, single layered stratocumulus clouds, broken shallow cumulus clouds and high level cirrus clouds respectively will be presented.

  2. Study of the evening transition to the nocturnal atmospheric boundary layer: statistical analysis and case studies

    NASA Astrophysics Data System (ADS)

    Sastre, Mariano; Viana, Samuel; Maqueda, Gregorio; Yagüe, Carlos

    2010-05-01

    Turbulence is probably the most important feature dealing with the diffusion of contaminants in the planetary boundary layer. The main characteristics of turbulence are governed, apart from synoptic conditions, by the daily cycle of the Earth surface heating and cooling, so that, simplifying, two configurations are often found: convective and stable. The transition from a diurnal convective boundary layer to a typically stable nocturnal one is not still well understood (Edwards, 2009). Different micrometeorological conditions at sunset or a few hours previously may be critical for the establishment of a strong surface-based stability or a weak one, even for similar synoptic conditions. This work focuses on the characterization of the evening transition which takes place at the atmospheric boundary layer, considering the temporal interval 17.00-23.00 GMT. The methodology includes looking for some relations between meteorological variables, turbulent parameters and particulate matter (PM10, PM2.5 and PM1) concentrations measured by a GRIMM particle monitor (MODEL 365). Observational data (Summer 2009) is provided from permanent instrumentation at the Research Centre for the Lower Atmosphere (CIBA) in Valladolid (Spain), which is on a quite flat terrain (Cuxart et al., 2000). A 10m height mast equipped with temperature, wind speed and direction, and moisture sensors at several levels are available. Also two sonic anemometers (20 Hz sampling rate) at 1.5 and 10m were deployed in the mast. The database is complemented by a triangle of microbarometers installed next to the surface, and another three microbarometers placed in a 100m meteorological tower at 20, 50 and 100m respectively, which are ideal to study coherent structures present in the boundary layer. Statistical parameters of meteorological variables have been calculated and studied in order to find out connections with the most relevant physical processes. Moreover different cases studies will be analyzed

  3. Using Case Studies as a Tool for Teaching Science Policy within the Atmospheric and Space Sciences

    NASA Astrophysics Data System (ADS)

    Fisher, G.; Hooke, W.

    2006-12-01

    Earth system science is a field where policy, societal, & economic aspects are becoming increasingly important as our society becomes more dependent on activities and technologies that affect and are affected by the Earth system. It is important that present and future scientists are prepared to fully participate in the challenging opportunities that lie ahead, including communicating to policy makers, making public policy decisions, & communicating science to the public. One way of providing a better foundation is to integrate policy and science at universities. Therefore, the American Meteorological Society Policy Program (APP) is developing materials for university science policy curricula and the AMS Summer Policy Colloquium. In providing policy education activities and promoting policy research, the APP hopes to encourage more people to enter the field of science policy, contribute to and enhance the current policy dialogue, and create a clearinghouse for science policy case studies. Case studies are an excellent method to study policy issues in the atmospheric and space sciences for the following reasons: issues are too complex to be handled by any single factor (economic, social, or political science); purpose is to identify and analyze the impacts rather than test theoretical hypotheses; problems involve large number of participants (government at various levels, industries, and researchers); and study requires giving alternatives and consequence analysis for policy makers. Lessons learned will be presented on implementation of science policy case studies at the AMS Summer Policy Colloquium and George Mason University.

  4. Atmospheric pollution: a case study of degrading urban air quality over Punjab, India.

    PubMed

    Sehra, Parmjit Singh

    2007-01-01

    This paper presents the results of a case study of urban air quality over a densely populated city Ludhiana situated in Punjab, India, in the form of monthly and annual average concentrations of Suspended Particulate Matter (SPM), NO2 and SO2 for the periods 1988-1989, 1994-1999 and 2001-2005 which is generally found to be increasing with time and thus requires immediate corrective measures lest the situation becomes totally uncontrollable. The present situation is as bad as in other metropolitan Indian cities, although it seems to have somewhat improved as indicated by the latest 2001-2005 data in comparison with the past 1988-1989 and 1994-1999 data, but much more still needs to be done. In addition to the industrial and vehicular pollution, the agricultural pollution due to the burning of wheat and rice straws by the farmers should also be checked because it also creates tremendous pollution in the atmosphere. PMID:18472555

  5. Satellite radiothermovision of atmospheric mesoscale processes: case study of tropical cyclones

    NASA Astrophysics Data System (ADS)

    Ermakov, D. M.; Sharkov, E. A.; Chernushich, A. P.

    2015-04-01

    Satellite radiothermovision is a set of processing techniques applicable for multisource data of radiothermal monitoring of oceanatmosphere system, which allows creating dynamic description of mesoscale and synoptic atmospheric processes and estimating physically meaningful integral characteristics of the observed processes (like avdective flow of the latent heat through a given border). The approach is based on spatiotemporal interpolation of the satellite measurements which allows reconstructing the radiothermal fields (as well as the fields of geophysical parameters) of the ocean-atmosphere system at global scale with spatial resolution of about 0.125° and temporal resolution of 1.5 hour. The accuracy of spatiotemporal interpolation was estimated by direct comparison of interpolated data with the data of independent asynchronous measurements and was shown to correspond to the best achievable as reported in literature (for total precipitable water fields the accuracy is about 0.8 mm). The advantages of the implemented interpolation scheme are: closure under input radiothermal data, homogeneity in time scale (all data are interpolated through the same time intervals), automatic estimation of both the intermediate states of scalar field of the studied geophysical parameter and of vector field of effective velocity of advection (horizontal movements). Using this pair of fields one can calculate the flow of a given geophysical quantity though any given border. For example, in case of total precipitable water field, this flow (under proper calibration) has the meaning of latent heat advective flux. This opportunity was used to evaluate the latent heat flux though a set of circular contours, enclosing a tropical cyclone and drifting with it during its evolution. A remarkable interrelation was observed between the calculated magnitude and sign of advective latent flux and the intensity of a tropical cyclone. This interrelation is demonstrated in several examples of

  6. Atmospheric Emissions from Forest Biomass Residues to Energy Supply Chain: A Case Study in Portugal

    PubMed Central

    Rafael, Sandra; Tarelho, Luis; Monteiro, Alexandra; Monteiro, Tânia; Gonçalves, Catarina; Freitas, Sylvio; Lopes, Myriam

    2015-01-01

    Abstract During the past decades, pressures on global environment and energy security have led to an increasing demand on renewable energy sources and diversification of the world's energy supply. The Portuguese energy strategy considers the use of Forest Biomass Residues (FBR) to energy as being essential to accomplish the goals established in the National Energy Strategy for 2020. However, despite the advantages pointing to FBR to the energy supply chain, few studies have evaluated the potential impacts on air quality. In this context, a case study was selected to estimate the atmospheric emissions of the FBR to the energy supply chain in Portugal. Results revealed that production, harvesting, and energy conversion processes are the main culprits for the biomass energy supply chain emissions (with a contribution higher than 90%), while the transport processes have a minor importance for all the pollutants. Compared with the coal-fired plants, the FBR combustion produces lower greenhouses emissions, on a mass basis of fuel consumed; the same is true for NOX and SO2 emissions. PMID:26064039

  7. Assessing the Oxidative Capacity of the Atmosphere: MCMA-2003 as a Case Study

    NASA Astrophysics Data System (ADS)

    Sheehy, P. M.; Volkamer, R. M.; Velasco, E.; Alexander, M.; Jobson, T.; Lamb, B.; Molina, L. T.

    2006-12-01

    The current understanding of oxidative capacity is assessed in the polluted atmosphere, using the Mexico City Metropolitan Area (MCMA) as a case study. Measurements from the MCMA-2003 field campaign are used to constrain a photochemical box model in order to study the impact of primary HOx} radical production and ROx} radical cycling on photochemical ozone and the oxidation of VOCs that is relevant for secondary organic aerosol (SOA) formation. Time-resolved HOx} (OH and HO2) radical fluxes were experimentally quantified from the photolysis of nitrous acid (HONO), formaldehyde (HCHO), ozone (O3), acetaldehyde (CCHO), glyoxal (CHOCHO) and the reaction of alkenes with O3. The Master Chemical Mechanism (MCMv3.1), constrained for these primary HOx} radical fluxes and radical sinks (103 VOC, NO, NO2, CO, and SO2), is used to calculate primary HOx} radical fluxes from other closed shell molecules, i.e. that form as VOC oxidation products. HCHO is found to be the most important source, dominating the overall HOx} radical flux shortly after sunrise. HOx} radical production from HCHO is matched only by O3 photolysis during "high O3" days (and HONO in the early morning); photolysis of secondary products is estimated to contribute some 30% to primary HOx} radical fluxes at noontime. MCMv3.1 is used to identify the VOC precursors of photochemical HCHO. Noontime concentrations of HONO reached 120 ppt on some days, indicating a substantial source of daytime HONO is operative in Mexico City. HONO formation is separated into dark-, daytime- and photo-stationary steady state (PSS) sources. MCMv3.1 is also used to predict OH, HO2, RO2, and RO concentrations (in sum termed ROx}). Measured and modeled concentrations are compared for the following case studies: HOx}-unconstrained, OH-constrained, HO2-constrained, HOx}-constrained. For the HOx}-unconstrained case, a significant under-prediction of OH and HO2 radicals is observed in the early morning. This "missing reactivity" is highest

  8. Biomagnetic monitoring of heavy metals contamination in deposited atmospheric dust, a case study from Isfahan, Iran.

    PubMed

    Norouzi, Samira; Khademi, Hossein; Cano, Angel Faz; Acosta, Jose A

    2016-05-15

    Tree leaves are considered as one of the best biogenic dust collectors due to their ability to trap and retain particulate matter on their surfaces. In this study, the magnetic susceptibility (MS) and the concentration of selected heavy metals of plane tree (Platanus orientalis L.) leaves and deposited atmospheric dust, sampled by an indirect and a direct method, respectively, were determined to investigate the relationships between leaf magnetic parameters and the concentration of heavy metals in deposited atmospheric dust. The objective was to develop a biomagnetic method as an alternative to the common ones used for determining atmospheric heavy metal contaminations. Plane tree leaves were monthly sampled on the 19th of May to November, 2012 (T1-T7), for seven months from 21 different sites in the city of Isfahan, central Iran. Deposited atmospheric dust samples were also collected using flat glass surfaces from the same sites on the same dates, except for T1. MS (χlf, χhf) values in washed (WL) and unwashed leaves (UL) as well as Cu, Fe, Mn, Ni, Pb, and Zn concentrations in UL and deposited atmospheric dust samples were determined. The results showed that the MS content with a biogenic source was low with almost no significant change during the sampling period, while an increasing trend was observed in the MS content of UL samples due to the deposition of heavy metals and magnetic particles on leaf surfaces throughout the plant growth. The latter type of MS content could be reduced through washing off by rain. Most heavy metals examined, as well as the Tomlinson pollution load index (PLI) in UL, showed statistically significant correlations with MS values. The correlation between heavy metals content in atmospheric dust deposited on glass surfaces and leaf MS values was significant for Cu, Fe, Pb, and Zn. Moreover, the similarity observed between the spatial distribution maps of leaf MS and deposited atmospheric dust PLI provided convincing evidence regarding

  9. Atmospheric nitrogen deposition budget in a subtropical hydroelectric reservoir (Nam Theun II case study, Lao PDR)

    NASA Astrophysics Data System (ADS)

    Adon, Marcellin; Galy-Lacaux, Corinne; Serça, Dominique; Guerin, Frederic; Guedant, Pierre; Vonghamsao, Axay; Rode, Wanidaporn

    2016-04-01

    With 490 km² at full level of operation, Nam Theun 2 (NT2) is one of the largest hydro-reservoir in South East Asia. NT2 is a trans-basin hydropower project that diverts water from the Nam Theun river (a Mekong tributary) to the Xe Ban Fai river (another Mekong tributary). Atmospheric deposition is an important source of nitrogen (N), and it has been shown that excessive fluxes of N from the atmosphere has resulted in eutrophication of many coastal waters. A large fraction of atmospheric N input is in the form of inorganic N. This study presents an estimation of the atmospheric inorganic nitrogen budget into the NT2 hydroelectric reservoir based on a two-year monitoring (July 2010 to July 2012) including gas concentrations and precipitation. Dry deposition fluxes are calculated from monthly mean surface measurements of NH3, HNO3 and NO2 concentrations (passive samplers) together with simulated deposition velocities, and wet deposition fluxes from NH4+ and NO3- concentrations in single event rain samples (automated rain sampler). Annual rainfall amount was 2500 and 3160 mm for the two years. The average nitrogen deposition flux is estimated at 1.13 kgN.ha-1.yr-1 from dry processes and 5.52 kgN.ha-1.yr-1 from wet ones, i.e., an average annual total nitrogen flux of 6.6 kgN.ha-1.yr-1 deposited into the NT2 reservoir. The wet deposition contributes to 83% of the total N deposition. The nitrogen deposition budget has been also calculated over the rain tropical forest surrounding the reservoir. Due to higher dry deposition velocities above forested ecosystems, gaseous dry deposition flux is estimated at 4.0 kgN.ha-1.yr-1 leading to a total nitrogen deposition about 9.5 kgN.ha-1.yr-1. This result will be compared to nitrogen deposition in the African equatorial forested ecosystems in the framework of the IDAF program (IGAC-DEBITS-AFrica).

  10. Seasonal variability of soil sink for atmospheric hydrogen: a case study from southern Poland

    NASA Astrophysics Data System (ADS)

    Bartyzel, J.; Pycia, M.; Necki, J. M.; Rozanski, K.

    2009-04-01

    Although hydrogen is rarely mentioned as a greenhouse gas, it is expected that elevated concentrations of this gas in the atmosphere in the coming decades, associated with massive anthropogenic emissions may lead to longer residence time of atmospheric CH4 and associated enhancement of the greenhouse effect. The global average mixing ratio of atmospheric H2 amounts at present to approximately 500 ppb. The sources and sinks of hydrogen are not well quantified. In particular, little is known about the strength and spatial and temporal variability of hydrogen uptake by soils. The EU 6th Framework Project EUROHYDROS is aimed at initialising European monitoring capability for atmospheric hydrogen, including the ability to derive isotope ratios and to use these observations, together with studies on sinks and sources of H2 and modelling work, to improve the understanding of hydrogen budget on the global scale. As a part of EUROHYDROS project, a dedicated study aimed at quantifying seasonal variability of soil sink for atmospheric hydrogen is being conducted in southern Poland. The experimental site is located on the outskirts of Krakow, a large city with numerous anthropogenic sources of H2. To quantify the soil sink for H2, a dedicated equipment has been constructed, based on the inverted cap principle. To quantify the uptake of H2 by soils, a 20-liter chamber made of stainless steel and plexiglas is placed on the soil surface and concentration of hydrogen inside the chamber is measured in regular time intervals in order to quantify the dynamics H2 removal via enzymatic reactions taking place in the upper soil layers. The concentration of hydrogen was measured in samples of air collected under the chamber in specified time intervals. A commercially available instrument (Peak Performer 1, Peak Laboratories, USA) equipped with RGA detector was used for this purpose. The measurements were performed regularly every two weeks. Apart of hydrogen concentrations, also several

  11. Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph A., Jr.; Peters-Lidard, Christa; Kennedy, Aaron D.

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address deficiencies in numerical weather prediction and climate models due to improper treatment of L-A interactions, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land-PBL coupling at the process-level. In this study, a diagnosis of the nature and impacts oflocalland-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of2006-7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which provides a flexible and high-resolution representation and initialization of land surface physics and states. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are examined for the dry/wet regimes of this region, along with the behavior and accuracy of different land-PBL scheme couplings under these conditions. In addition, we examine the impact of improved specification ofland surface states, anomalies, and fluxes that are obtained through the use of a hew optimization and uncertainty module in LIS, on the L-A coupling in WRF forecasts. Results demonstrate how LoCo diagnostics can be applied to coupled model components in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and support of hydrological anomalies.

  12. Pre-atmospheric parameters and fragment distribution: Case study for the Kosice meteoroid

    NASA Astrophysics Data System (ADS)

    Gritsevich, M.; Vinnikov, V.; Kuznetsova, D.; Kohout, T.; Pupyrev, Y.; Peltoniemi, J.; Tóth, J.; Britt, D.; Turchak, L.; Virtanen, J.

    2014-07-01

    We present results on our investigation on the Košice meteorite --- one of the recent falls with a well-derived trajectory and large number of recovered fragments. A fireball appeared over central-eastern Slovakia on February 28, 2010. The bolide reached an absolute magnitude of at least -18, enabling radiometers of the European Fireball Network to track the fireball despite the cloudy and rainy weather. The landing area was successfully computed on the basis of data from the surveillance cameras operating in Hungary and led to a fast meteorite recovery (Borovička et al. 2013). The first reported fragment of the meteorite was located northwest of the city of Košice in eastern Slovakia (Tóth et al. 2014). 218 fragments of the Košice meteorite, with a total mass of 11.285 kg, have been documented with almost 7 kg belonging to the collection of the Comenius University in Bratislava and Astronomical Institute of Slovak Academy of Sciences (Gritsevich et al. 2014). Based on the statistical investigation of the recovered fragments, bimodal Weibull, bimodal Grady, and bimodal lognormal distributions are found to be the most appropriate distributions for describing the Košice fragmentation process. The most probable scenario suggests that the Košice meteoroid, prior to further extensive fragmentation in the lower atmosphere, was initially represented by two independent pieces with cumulative residual masses of approximately 2 kg and 9 kg respectively (Gritsevich et al. 2014). About 1/3 of the recovered Košice fragments were thoroughly studied, including magnetic susceptibility, bulk and grain density measurements reported by Kohout et al. (2014). This analysis revealed that the Košice meteorites are H5 ordinary chondrites that originated from a homogenous parent meteoroid. To estimate the dynamic mass of the main fragment, we studied the first integral of the drag and mass-loss equations, and the geometrical relation along the meteor trajectory in the atmosphere

  13. Sources of dissolved mine drainage and atmospheric transported lead: a comparative case study in Japan and Sweden.

    PubMed

    Aberg, Göran; Satake, Kenichi

    2009-12-15

    A comparative case study in Naganobori Japan and Falun Sweden of runoff water from copper mines shows that the water and its particulates, filtered with a cutoff of 0.45 microm, have different lead isotope ratios pointing to different origins for the lead. While the larger particles have a lead ratio indicative of the atmospheric anthropogenic pollution the soluble lead has that of the copper ores. The domestic atmospheric lead ratio in Japan is homogeneous and characteristic of emissions from the incineration of waste. Lead pollution transported from the Asian continent by westerly winds can be distinguished from the Japanese pollution by its more thorogenic lead ratios, in for example analyses of copper moss from Naganobori. PMID:19833378

  14. Thermal degradation of organics for pyrolysis in space: Titan's atmospheric aerosol case study

    NASA Astrophysics Data System (ADS)

    He, Jing; Buch, Arnaud; Carrasco, Nathalie; Szopa, Cyril

    2015-03-01

    Pyrolysis coupled with mass spectry is among the instrumentation the most implemented in planetary exploration probes to analyze the chemical composition of extraterrestrial solid samples. It is used to analyze the volatile species which can be thermally extracted from the samples, including the organic fraction which is of primary interest for astrobiological purposes. However the thermal degradation of these organic materials, which can be very complex in nature or very different from organics commonly present on Earth, is badly known. This leads to a restriction in the optimization of space instrumentation, and in the interpretation of the measurements. In the present work we propose a complete overview of the thermal degradation processes studied on a model of complex organic material produced in an extraterrestrial environment, i.e. laboratory analogues of Titan's atmospheric aerosols. The thermal evolution of the studied analogues is monitored by following their mass loss, the emitted heating flux, and the evolution of their chemical composition through infrared spectroscopy and elemental analysis. The gaseous products released from the material are also analyzed by mass spectrometry, allowing to better constrain the mechanisms of chemical evolution of the samples. The complex organic material analyzed is found not to be fully decomposed when heated up to about 800 °C, with the evidence that nitrogen is still deeply incorporated in the remaining graphitic carbon nitride residue. The most appropriate pyrolysis temperature to chemically probe the studied material is found to be about 450 °C because at this temperature are detected the largest gaseous molecules which should be the most representative ones of the material pyrolyzed.

  15. Detection and Modeling of Temperature Inversion in the Atmosphere Using Modis Images (case Study: Kermanshah)

    NASA Astrophysics Data System (ADS)

    Kachar, H.; Mobasheri, M. R.; Abkar, A. A.; Rahim Zadegan, M.

    2015-12-01

    Increase of temperature with height in the troposphere is called temperature inversion. Parameters such as strength and depth are characteristics of temperature inversion. Inversion strength is defined as the temperature difference between the surface and the top of the inversion and the depth of inversion is defined as the height of the inversion from the surface. The common approach in determination of these parameters is the use of Radiosonde where these measurements are too sparse. The main objective of this study is detection and modeling the temperature inversion using MODIS thermal infrared data. There are more than 180 days per year in which the temperature inversion conditions are present in Kermanshah city. Kermanshah weather station was selected as the study area. 90 inversion days was selected from 2007 to 2008 where the sky was clear and the Radiosonde data were available. Brightness temperature for all thermal infrared bands of MODIS was calculated for these days. Brightness temperature difference between any of the thermal infrared bands of MODIS and band 31 was found to be sensitive to strength and depth of temperature inversion. Then correlation coefficients between these pairs and the inversion depth and strength both calculated from Radiosonde were evaluated. The results showed poor linear correlation. This was found to be due to the change of the atmospheric water vapor content and the relatively weak temperature inversion strength and depth occurring in Kermanshah. The polynomial mathematical models and Artificial intelligence algorithms were deployed for detection and modeling the temperature inversion. A model with the lowest terms and highest possible accuracy was obtained. The Model was tested using 20 independent test data. Results indicate that the inversion strength can be estimated with RMSE of 0.84° C and R2 of 0.90. Also inversion depth can be estimated with RMSE of 54.56 m and R2 of 0.86.

  16. Are coarse particles unexpected common reservoirs for some atmospheric anthropogenic trace elements? A case study

    NASA Astrophysics Data System (ADS)

    Catinon, Mickaël; Ayrault, Sophie; Boudouma, Omar; Bordier, Louise; Agnello, Gregory; Reynaud, Stéphane; Tissut, Michel

    2013-08-01

    Without specific experimental equipment, it is very difficult to sample long-term atmospheric deposits on a pure state. That is why the composition of air-transferred solid material accumulated for 40 years in the 2 m-high walls, pierced with numerous holes of an outdoor public shelter, Grenoble city, France, was studied. An appropriate fractionation procedure allowed to obtain several fractions which were i) a sand fraction (8.3%) (fraction A), ii) a large mass of organic matter corresponding mostly to large fragments (>250 μm) of plant origin (66.7%) (fraction B) or to pollen fraction C (0.4%), iii) a slowly depositing organo-clay fraction (20%) (fractions D1 and D2) and iv) a solution mixed with non-settable particles (4.3%) (fraction E). The composition of each fraction was determined for 20 elements. The sand fraction showed very high concentrations specifically in Cu, Pb and Fe corresponding respectively to 81.5, 48.2 and 35.2% of the samples content in these elements. In contrast, Cd and Zn were mainly accumulated in the fraction B (67.5 and 62.2%, respectively). The scanning electron microscopy coupled to energy dispersive X-ray analysis (SEM-EDX) study of the fraction A showed the presence of large particles bearing Pb and Fe, particles rich in Cu and typical fly ashes originating mostly from iron industry. Most of these particles had a crystalline shape suggesting that they were formed after emission at a high temperature. The Pb-Fe-Cu deposit seen in fraction A likely originates from the neighbouring road surface contaminated by car traffic for several decades. The 206Pb/207Pb ratio (1.146 ± 0.004) showed that in the coarse sandy fraction A, Pb was represented at 65% by non-gasoline lead and 35% by "gasoline" lead emitted before 1999. The fraction A particles can only be transported on a limited distance by high magnitude events. They constitute a large reservoir for Cu and Pb and may play a major role in the long-term contamination of urban soils.

  17. Study of atmospheric surface layer electrical processes in case of varying intensity rain

    NASA Astrophysics Data System (ADS)

    Pustovalov, K. N.; Kobzev, A. A.; Nagorskiy, P. M.

    2015-11-01

    The variations of the surface potential gradient, and positive and negative air electric conductivities during the passage of the series of atmospheric fronts, which were accompanied by the showers and continuous rains, are investigated. According to the analysis of experimental data, the distortion of the related variations of the potential gradient and air electric conductivities occurred during rain. The value of this distortion depends on the rain type and the rain rate.

  18. Study of atmospheric dynamics

    NASA Technical Reports Server (NTRS)

    Mcnider, Richard T.; Christy, John R.; Cox, Gregory N.

    1993-01-01

    In order to better understand the dynamics of the global atmosphere, a data set of precision temperature measurements was developed using the NASA built Microwave Sounding Unit. Modeling research was carried out to validate global model outputs using various satellite data. Idealized flows in a rotating annulus were studied and applied to the general circulation of the atmosphere. Dynamic stratospheric ozone fluctuations were investigated. An extensive bibliography and several reprints are appended.

  19. A case study of multi-annual temperature oscillations in the atmosphere: Middle Europe

    NASA Astrophysics Data System (ADS)

    Offermann, D.; Goussev, O.; Kalicinsky, Ch.; Koppmann, R.; Matthes, K.; Schmidt, H.; Steinbrecht, W.; Wintel, J.

    2015-12-01

    SABER temperature measurements from 2002 to 2012 are analyzed from 18 to 110 km altitude in Middle Europe. Data are complemented by radiosonde measurements in the altitude range from 0 to 30 km. Low frequency oscillations with periods of about 2.4-2.2 yr, 3.4 yr, and 5.5 yr are seen in either data set. Surprising vertical structures in amplitudes and phases are observed with alternating minima and maxima of amplitudes, steep phase changes (180°) at the altitudes of the minima, and constant phase values in between. HAMMONIA CCM simulations driven by boundary conditions for the years 1996-2006 are analyzed for corresponding features, and very similar structures are found. Data from another CCM, the CESM-WACCM model, are also analyzed and show comparable results. Similar oscillation periods have been reported in the literature for the ocean. A possible forcing of the atmospheric oscillations from below was therefore tested with a special HAMMONIA run. Here, climatological boundary conditions were used, i.e. the boundaries in all eleven years were the same. Surprisingly also in this data set the same atmospheric oscillations are obtained. We therefore conclude that the oscillations are intrinsically forced, self-sustained in the atmosphere. The oscillations turned out to be quite robust as they are still found in a HAMMONIA run with strongly reduced vertical resolution. Here only the form of the vertical amplitude and phase profile of the 2.2 yr feature is lost but the oscillation itself is still there, and the two other oscillations are essentially unchanged. Similar oscillations are seen in the earth surface temperatures. Global Land Ocean Temperature Index data (GLOTI) reaching back to 1880 show such oscillations during all that time. The oscillations are also seen in parameters other than atmospheric temperature. They are found in surface data such as the North Atlantic Oscillation Index (NAO) and in zonal winds in the troposphere and lower stratosphere. The

  20. The impact of atmospheric composition on plants: a case study of ozone and poplar.

    PubMed

    Renaut, Jenny; Bohler, Sacha; Hausman, Jean-François; Hoffmann, Lucien; Sergeant, Kjell; Ahsan, Nagib; Jolivet, Yves; Dizengremel, Pierre

    2009-01-01

    Tropospheric ozone is the main atmospheric pollutant that causes damages to trees. The estimation of the threshold for ozone risk assessment depends on the evaluation of the means that this pollutant impacts the plant and, especially, the foliar organs. The available results show that, before any visible symptom appears, carbon assimilation and the underlying metabolic processes are decreased under chronic ozone exposure. By contrast, the catabolic pathways are enhanced, and contribute to the supply of sufficient reducing power necessary to feed the detoxification processes. Reactive oxygen species delivered during ozone exposure serve as toxic compounds and messengers for the signaling system. In this review, we show that the contribution of genomic tools (transcriptomics, proteomics, and metabolomics) for a better understanding of the mechanistic cellular responses to ozone largely relies on spectrometric measurements. PMID:18985755

  1. The link between atmospheric blockings and Central European flood events - A case study

    NASA Astrophysics Data System (ADS)

    Lenggenhager, Sina; Martius, Olivia; Brönnimann, Stefan; Croci-Maspoli, Mischa

    2016-04-01

    Flood events are among the most devastating weather-related events in Europe and can lead to large economic losses and even fatalities. Several processes, such as heavy precipitation or snow melt, can be involved in the triggering of flood events. Here we focus on precipitation only. Important characteristics of the flood triggering precipitation events are their intensity and their duration, which in return depend on the intensity and the stationarity of the associated weather system. Atmospheric blockings, due to their longevity and stationarity can influence flood related precipitation event in several ways: i) The progression of the upstream weather systems is slowed and thereby the precipitation period over a catchment can be prolonged. ii) The cumulative effect of recurrent precipitation events occurring up- or downstream of a block can result in a flood event. The interaction between blockings and flood triggering weather events potentially works in both directions. Cloud diabatic processes can be central to the establishment and maintenance of blocking anticyclones. The precipitation responsible for the flood could hence potentially extend the lifetime and strength of a blocking anticyclone located downstream of the flooded area. Here we illustrate the different interactions based on a flood event of a major lake in southern Switzerland in October 2000. During the flood event and in the month before blockings were present downstream, over Scandinavia as well as upstream, over the North-Atlantic. Three extreme precipitation episodes occured in southern Switzerland in September and October 2000. The first one took place on 20 September and was associated with an atmospheric blocking over the north Atlantic. This blocking together with a downstream anticyclone led to the formation of a PV streamer over western Europe that was responsible for the heavy precipitation. The two anticyclonic systems then merged and formed a persistent blocking over the northern

  2. Data-driven Ontology Development: A Case Study at NASA's Atmospheric Science Data Center

    NASA Astrophysics Data System (ADS)

    Hertz, J.; Huffer, E.; Kusterer, J.

    2012-12-01

    Well-founded ontologies are key to enabling transformative semantic technologies and accelerating scientific research. One example is semantically enabled search and discovery, making scientific data accessible and more understandable by accurately modeling a complex domain. The ontology creation process remains a challenge for many anxious to pursue semantic technologies. The key may be that the creation process -- whether formal, community-based, automated or semi-automated -- should encompass not only a foundational core and supplemental resources but also a focus on the purpose or mission the ontology is created to support. Are there tools or processes to de-mystify, assess or enhance the resulting ontology? We suggest that comparison and analysis of a domain-focused ontology can be made using text engineering tools for information extraction, tokenizers, named entity transducers and others. The results are analyzed to ensure the ontology reflects the core purpose of the domain's mission and that the ontology integrates and describes the supporting data in the language of the domain - how the science is analyzed and discussed among all users of the data. Commonalities and relationships among domain resources describing the Clouds and Earth's Radiant Energy (CERES) Bi-Directional Scan (BDS) datasets from NASA's Atmospheric Science Data Center are compared. The domain resources include: a formal ontology created for CERES; scientific works such as papers, conference proceedings and notes; information extracted from the datasets (i.e., header metadata); and BDS scientific documentation (Algorithm Theoretical Basis Documents, collection guides, data quality summaries and others). These resources are analyzed using the open source software General Architecture for Text Engineering, a mature framework for computational tasks involving human language.

  3. Atmospheric correction in time-series SAR interferometry for land surface deformation mapping - A case study of Taiyuan, China

    NASA Astrophysics Data System (ADS)

    Tang, Wei; Liao, Mingsheng; Yuan, Peng

    2016-08-01

    The dominant error source of Synthetic Aperture Radar Interferometry (InSAR) is atmospheric phase screen (APS), resulting in phase delay of the radar signal propagating through the atmosphere. The APS in the atmosphere can be decomposed into stratified and turbulent components. In this paper, we introduced a method to compensate for stratified component in a radar interferogram using ERA-Interim reanalysis products obtained from European Centre for Medium-Range Weather Forecasts (ECMWF). Our comparative results with radiosonde data demonstrated that atmospheric condition from ERA-Interim could produce reasonable patterns of vertical profiles of atmospheric states. The stratified atmosphere shows seasonal changes which are correlated with time. It cannot be properly estimated by temporal high-pass filtering which assumes that atmospheric effects are random in time in conventional persistent scatterer InSAR (PSI). Thus, the estimated deformation velocity fields are biased. Therefore, we propose the atmosphere-corrected PSI method that the stratified delay are corrected on each interferogram by using ERA-Interim. The atmospheric residuals after correction of stratified delay were interpreted as random variations in space and time which are mitigated by using spatial-temporal filtering. We applied the proposed method to ENVISAT ASAR images covering Taiyuan basin, China, to study the ground deformation associated with groundwater withdrawal. Experimental results show that the proposed method significantly mitigate the topography-correlated APS and the estimated ground displacements agree more closely with GPS measurements than the conventional PSI.

  4. Studying Air Quality Dynamics using A Linear Genetic Programming Approach over Remotely Sensed Atmospheric Parameters: case study (Cairo, Egypt)

    NASA Astrophysics Data System (ADS)

    El-Askary, H. M.; Sheta, W.; Prasad, A. K.; Ali, H.; Abdel rahman, M.; El-Desouki, A.; Kafatos, M.

    2011-12-01

    For the past nine years starting from 2000, Cairo and the Delta region have been going through seriously high air pollution episodes that take place from October till November, locally known as the "Black Cloud". These temperature inversion episodes are attributed to Cairo's topography, complex climate systems, in addition to its economic growth and industrial activity and the long range transport from Europe. Carbon monoxide, ozone, methane, and water vapor are four major parameters that give an indication to the levels of pollution due to their interactions in the atmosphere. Carbon monoxide is especially an excellent tracer for pollution sources and pathways in the troposphere. The Nile Delta is known to be the most populous region of Egypt with major agricultural and industrial activities. The region suffers from intense episodes of natural and anthropogenic pollution especially during Spring (MAM), Summer (JJA), Fall (SON), and Winter (DJF) seasons. Previous studies found that the summer season shows long range transport of pollutants from Europe which is widely accepted. Recent studies attribute the local biomass burning in open fields to be the major culprit behind increased levels of pollution over major cities of the Delta region (such as Cairo) especially during the Fall season. Such episodes result in dense fog and haze which is locally known as "Black Cloud". We have analyzed multiple satellite datasets such as MODIS higher resolution daily aerosol parameters, vertical profiles from AIRS (meteorological and other parameters), HYSPLIT and GOCART models, and ground collected data (AOD, PM10, SO2 and NO2) to study the cause of Fall-time pollution over the Delta region. In this research we analysed aerosol, water vapor and cloud properties, over Cairo and the Greater Delta region starting from March 1st 2000 till May 31st 2010. The parameters involved in this analysis include nine parameters noted as P0 to P8 namely: Angstrom Exponent Land Mean, Atmospheric

  5. On the Radon mechanism of the Lithosphere-Atmosphere coupling. Tlamacas mountain case study, volcano Popocatepetl area, Mexico

    NASA Astrophysics Data System (ADS)

    Kotsarenko, A.; Grimalsky, V.; Yutsis, V. V.; Koshevaya, S.; Bravo Osuna, A.

    2013-05-01

    Results on Radon monitoring in 3 different sites in volcano Popocatepetl and referent site revealed Radon depletion anticipating 9 cases of moderate eruptive activity among 23 total events. The most pronounced reaction was observed in Tlamacas observational site. The averaged Radon concentration in Paso de Cortes and Tlamacas 2 sites is significantly lower in comparison with that at Tlamacas; the Radon variation in the mentioned sites has many specific features meanwhile in the Tlamacas site Radon behavior emphasizes a more individual character. The combined study by means of Radon survey, Gamma ray, Uranium, Thorium and Potassium spectrometry revealed an anomalously increased diffusion Radon emanation localized in the area of Tlamacas. Complementary geophysical studies by methods of gravimetric and magnetic prospection make credible postulation about volcanic origin of Tlamacas mountain. Observed zonal geological structures in the Tlamacas mountain and surrounding area may stimulate intensive Radon emanation from the volcanic depth. A new conception is proposed regarding a Lithosphere-Atmosphere coupling in the case of Tlamacas being similar in nature with a shortened electrical circuit Earth—thunderstorm clouds (high-altitude mountains) so that an enhanced ionization caused by intensive Radon release may explain in a novel way the noise-like geomagnetic emission observed before destructive earthquakes and volcanic eruptions. Numerical simulation gives values of geomagnetic perturbations 10-3 - 10-1 nT under "normal" conditions which can easily transform into the range 1 - 10 nT in the case of higher electric field E > 1 kV/m which is typical for mountains.

  6. Measurement of atmospheric mercury species with manual sampling and analysis methods in a case study in Indiana

    USGS Publications Warehouse

    Risch, M.R.; Prestbo, E.M.; Hawkins, L.

    2007-01-01

    Ground-level concentrations of three atmospheric mercury species were measured using manual sampling and analysis to provide data for estimates of mercury dry deposition. Three monitoring stations were operated simultaneously during winter, spring, and summer 2004, adjacent to three mercury wet-deposition monitoring stations in northern, central, and southern Indiana. The monitoring locations differed in land-use setting and annual mercury-emissions level from nearby sources. A timer-controlled air-sampling system that contained a three-part sampling train was used to isolate reactive gaseous mercury, particulate-bound mercury, and elemental mercury. The sampling trains were exchanged every 6 days, and the mercury species were quantified in a laboratory. A quality-assurance study indicated the sampling trains could be held at least 120 h without a significant change in reactive gaseous or particulate-bound mercury concentrations. The manual sampling method was able to provide valid mercury concentrations in 90 to 95% of samples. Statistical differences in mercury concentrations were observed during the project. Concentrations of reactive gaseous and elemental mercury were higher in the daytime samples than in the nighttime samples. Concentrations of reactive gaseous mercury were higher in winter than in summer and were highest at the urban monitoring location. The results of this case study indicated manual sampling and analysis could be a reliable method for measurement of atmospheric mercury species and has the capability for supplying representative concentrations in an effective manner from a long-term deposition-monitoring network. ?? 2007 Springer Science+Business Media B.V.

  7. Atmospheric rendezvous feasibility study

    NASA Technical Reports Server (NTRS)

    Schaezler, A. D.

    1972-01-01

    A study was carried out to determine the feasibility of using atmospheric rendezvous to increase the efficiency of space transportation and to determine the most effective implementation. It is concluded that atmospheric rendezvous is feasible and can be utilized in a space transportation system to reduce size of the orbiter vehicle, provide a powered landing with go-around capability for every mission, and achieve lateral range performance that exceeds requirements. A significantly lighter booster and reduced launch fuel requirements are additional benefits that can be realized with a system that includes a large subsonic airplane for recovery of the orbiter. Additional reduction in booster size is possible if the airplane is designed for recovery of the booster by towing. An airplane about the size of the C-5A is required.

  8. Convectively Generated Gravity Waves In The Tropical Stratosphere: Case Studies And Importance For The Circulation Of The Middle Atmosphere

    NASA Technical Reports Server (NTRS)

    Pfister, Leonhard; Chan, Kwoklong R.; Gary, Bruce; Singh, Hanwant B. (Technical Monitor)

    1995-01-01

    The advent of high altitude aircraft measurements in the stratosphere over tropical convective systems has made it possible to observe the mesoscale disturbances in the temperature field that these systems excite. Such measurements show that these disturbances have horizontal scales comparable to those of the underlying anvils (about 50-100 km) with peak to peak theta surface variations of about 300-400 meters. Moreover, correlative wind measurements from the tropical phase of the Stratosphere-Troposphere Exchange Project (STEP) clearly show that these disturbances are gravity waves. We present two case studies of anvil-scale gravity waves over convective systems. Using steady and time-dependent linear models of gravity wave propagation in the stratosphere, we show: (1) that the underlying convective systems are indeed the source of the observed phenomena; and (2) that their generating mechanism can be crudely represented as flow over a time-dependent mountain. We will then discuss the effects gravity waves of the observed amplitudes have on the circulation of the middle atmosphere, particularly the quasi-biennial, and semiannual oscillations.

  9. Comparison of ground reflectance measurement with satellite derived atmospherically corrected reflectance: A case study over semi arid landscape

    NASA Astrophysics Data System (ADS)

    Rani Sharma, Anu; Badarinath, Kvs; Vikshalakshie Muthukumaraswamy Ganeshamoorthy, Ms; Roy, Parthsarathi

    Optical remote sensing data is contaminated due to scattering and absorption by aerosols, water vapour and trace gases in the atmosphere. In order to remove scattering and absorption effects and to derive precise surface reflectance from satellite image data, it is indispensable to apply the atmospheric correction. Various empirical methods and radiative transfer models that attempt to account for wavelength specific absorption and scattering are available in literature. Empirical methods include ratio, subtraction, and empirical line correction etc and the radiative transfer models include LOWTRAN, MODTRAN, 5S, 6S, SBDART and SMAC etc. Amongst these models Second Simulation of Satellite Signal in the Solar Spectrum (6S) has better options for different satellite sensors. In this study, we evaluated the potential of 6S radiative transfer model for atmospheric corrections of IRS AWiFS satellite data, in a semi-arid landscape. Ground measurements of surface reflectance over Maize and chic pea crop were conducted with spectroradiometer and compared with top of atmospheric reflectance derived from IRS-AWiFS. The 6S radiative transfer model was modified for local conditions using ground measurements on aerosol optical depth (AOD), water vapor and ozone using sun photometer. In order to extract surface reflectance from satellite data, individual bands digital numbers (DN) were first converted into spectral radiance (Li ) using pre launch calibration coefficients. The top of atmosphere (TOA) reflectance (˜(¨)i ) for each spectral band were then computed by ne converting spectral radiance to reflectance using the relation, n (¨) i =πLi d2 /E0 Cosθ (1); where, ˜ e Li is spectral radiance, d2 is Earth-Sun distance, E0 is the ex-atmospheric solar irradiance, θ is the solar zenith angle.Further the surface reflectance free from atmospheric effect, is computed as Ref = [(Aρ+ B] / [1 + ( Υ (Aρ + B))] (2); Where A= 1/αβ , B = -ρ / β and p = TOA reflectance, α is

  10. Description of the atmospheric circulation in the boundary layer over a tropical island: Case study of Guadeloupe Archipelago

    NASA Astrophysics Data System (ADS)

    Plocoste, Thomas; Dorville, Jean-François; Jacoby-Koaly, Sandra; Roussas, André

    2016-04-01

    Over past two decades the use of atmospheric sounding methods as Sodars, Lidar equipped drones increased sharply. Compare to weather balloon, these modern methods allow measure of profile at constant heights during long period. There are few studies using this type of equipment in tropical climates and lesser on small island. Wind regime on island of diameter less than 50 km are mostly considered as oceanic. Many author consider that thermal effect are negligible in land. But recent observations and simulations show importance of the thermal circulation at small- and meso- scales particularly in atmospheric pollution process. Up to 2009 no wind profile data were available continuously to study atmospheric circulation in Guadeloupe Archipelago (GA) which is one of the islands of the Lesser Antilles Arc. In first approximation wind was evaluated based on measures done at the most upwind island of the GA for many application as wind power and atmospheric pollution. From 2009 to 2012 a measurement campaign of the Atmospheric Boundary Layer (ABL) have been performed by the University of Antilles (UA) in GA. To assess effects of dynamic of ABL on air quality in sub urban area, particularly during the sunset and sunrise, UA monitored two sites with a weather station and a doppler sodar (REMTECH PAO). Both sites are close to the sea with one in a coastal area and the other in an open landfill surrounded by densely populated building and a mangrove swamp. Thermal and chemical measurements with a portable mass spectrometer were made in the vicinity of the landfill and showed the existence of urban heat islands. This study presents the first Doppler Sodar long measurements campaign in GA. Statistical analysis of the three year of doppler sodar data (i.e. wind components and its fluctuations) allow to identified and characterized the complex circulations on the two sites in the ABL between 25 and 500m above the sea level. Orographic and thermal effects due to urban area were

  11. The location of the thermodynamic atmosphere-ice interface in fully coupled models - a case study using JULES and CICE

    NASA Astrophysics Data System (ADS)

    West, Alex E.; McLaren, Alison J.; Hewitt, Helene T.; Best, Martin J.

    2016-03-01

    In fully coupled climate models, it is now normal to include a sea ice component with multiple layers, each having their own temperature. When coupling this component to an atmosphere model, it is more common for surface variables to be calculated in the sea ice component of the model, the equivalent of placing an interface immediately above the surface. This study uses a one-dimensional (1-D) version of the Los Alamos sea ice model (CICE) thermodynamic solver and the Met Office atmospheric surface exchange solver (JULES) to compare this method with that of allowing the surface variables to be calculated instead in the atmosphere, the equivalent of placing an interface immediately below the surface. The model is forced with a sensible heat flux derived from a sinusoidally varying near-surface air temperature. The two coupling methods are tested first with a 1 h coupling frequency, and then a 3 h coupling frequency, both commonly used. With an above-surface interface, the resulting surface temperature and flux cycles contain large phase and amplitude errors, and have a very blocky shape. The simulation of both quantities is greatly improved when the interface is instead placed within the top ice layer, allowing surface variables to be calculated on the shorter timescale of the atmosphere. There is also an unexpected slight improvement in the simulation of the top-layer ice temperature by the ice model. The surface flux improvement remains when a snow layer is added to the ice, and when the wind speed is increased. The study concludes with a discussion of the implications of these results to three-dimensional modelling. An appendix examines the stability of the alternative method of coupling under various physically realistic scenarios.

  12. Atmospheric corrections in interferometric synthetic aperture radar surface deformation - a case study of the city of Mendoza, Argentina

    NASA Astrophysics Data System (ADS)

    Balbarani, S.; Euillades, P. A.; Euillades, L. D.; Casu, F.; Riveros, N. C.

    2013-09-01

    Differential interferometry is a remote sensing technique that allows studying crustal deformation produced by several phenomena like earthquakes, landslides, land subsidence and volcanic eruptions. Advanced techniques, like small baseline subsets (SBAS), exploit series of images acquired by synthetic aperture radar (SAR) sensors during a given time span. Phase propagation delay in the atmosphere is the main systematic error of interferometric SAR measurements. It affects differently images acquired at different days or even at different hours of the same day. So, datasets acquired during the same time span from different sensors (or sensor configuration) often give diverging results. Here we processed two datasets acquired from June 2010 to December 2011 by COSMO-SkyMed satellites. One of them is HH-polarized, and the other one is VV-polarized and acquired on different days. As expected, time series computed from these datasets show differences. We attributed them to non-compensated atmospheric artifacts and tried to correct them by using ERA-Interim global atmospheric model (GAM) data. With this method, we were able to correct less than 50% of the scenes, considering an area where no phase unwrapping errors were detected. We conclude that GAM-based corrections are not enough for explaining differences in computed time series, at least in the processed area of interest. We remark that no direct meteorological data for the GAM-based corrections were employed. Further research is needed in order to understand under what conditions this kind of data can be used.

  13. Assessing the atmospheric and climatic effects of basaltic fissure eruptions. A case study Nornahraun, North Iceland, 2014-2015.

    NASA Astrophysics Data System (ADS)

    Gallagher, Catherine; Burton, Kevin; Thordarson, Thorvaldur; Vye-Brown, Charlotte; Brown, Richard

    2015-04-01

    A volcanic eruption's ability to release sulphur gases into the atmosphere is one of the critical factors in assessing their climatic and environmental effects, because it is directly linked to the potential H2SO4 aerosol burden produced [1]. Basaltic fissure eruptions loft large amounts of sulphur into the atmosphere because of the efficient degassing of volatiles and halogens from the magma at the vent [2-4] coupled with the high sulphur yield of basaltic magma. The common nature of this style of eruption and its products, regardless of magnitude, means that our understanding of the exact processes which influence atmospheric chemistry and environmental impact is very important. The Nornahraun fissure eruption in North Iceland that began on the 31st August 2014, has quickly become one of the best documented eruptions of its kind, through systematic monitoring and sampling by the Institute of Earth Sciences eruption team and The Icelandic Meteorological Office. As a result it is an excellent modern analogue for historic or ancient basaltic fissure eruptions, for which the amount of degassing can only be estimated through petrological and geochemical methods. It also serves as a timely testing platform for novel geochemical proxies. This study uses the exceptional sensitivity of the 187Os-187Re radiogenic system to the presence of crustal material [5], and highly siderophile stable isotopes Cu, Zn and S to indicate the chemistry and degassing of the melt carrying S to the surface. The geochemical isotopic proxies will be tested using established petrological methods and gas emission data. This study concentrates on determining the following key parameters: (1) The source of volatiles in the magma indicated though the pressure dependence of S solubility. (2) The mechanism of aerosol and gas release into the atmosphere is dictated both by the chemistry of the melt that controls the S species (H2S, SO2 or FeS2) present [6], and by the mechanism of transfer. (3) The

  14. Validation of the Atmospheric Infrared Sounder Water Vapor Retrievals Using Global Positioning System: Case Study in South Korea

    NASA Astrophysics Data System (ADS)

    Won, Jihye; Park, Kwan-Dong; Kim, Dusik; Ha, Jihyun

    2011-12-01

    The atmospheric infrared sounder (AIRS) sensor loaded on the Aqua satellite observes the global vertical structure of atmosphere and enables verification of the water vapor distribution over the entire area of South Korea. In this study, we performed a comparative analysis of the accuracy of the total precipitable water (TPW) provided as the AIRS level 2 standard retrieval product by Jet Propulsion Laboratory (JPL) over the South Korean area using the global positioning system (GPS) TPW data. The analysis TPW for the period of one year in 2008 showed that the accuracy of the data produced by the combination of the Advanced Microwave Sounding Unit sensor with the AIRS sensor to correct the effect of clouds (AIRS-X) was higher than that of the AIRS IR-only data (AIRS-I). The annual means of the root mean square error with reference to the GPS data were 5.2 kg/m2 and 4.3 kg/m2 for AIRS-I and AIRS-X, respectively. The accuracy of AIRS-X was higher in summer than in winter while measurement values of AIRS-I and AIRS-X were lower than those of GPS TPW to some extent.

  15. Sample damage during X-ray fluorescence analysis--case study on ammonium salts in atmospheric aerosols.

    PubMed

    Van Meel, Katleen; Worobiec, Anna; Stranger, Marianne; Van Grieken, René

    2008-08-01

    Atmospheric aerosols can consist of, amongst others, compounds like NH(4)NO(3) or (NH(4))(2)SO(4). Such components can suffer radiation damage and/or evaporate during EDXRF measurements, providing errors on successively applied analysis. The aim of this work is to investigate the influence of measurements using conventional EDXRF on the volatile compounds and to compare it with the influence of polarized beam EDXRF using secondary targets (and hence indirect irradiation). The effect of different parameters (acquisition time, accelerating voltage, current and medium) on the concentration loss was studied. The measurements performed in vacuum during a long period lead to the highest losses of volatile compounds. The influence of direct irradiation was proved to be larger than the indirect variant. PMID:18688470

  16. Atmospheric Entry Studies for Uranus

    NASA Astrophysics Data System (ADS)

    Agrawal, P.; Allen, G. A.; Hwang, H. H.; Marley, M. S.; McGuire, M. K.; Garcia, J. A.; Sklyanskiy, E.; Huynh, L. C.; Moses, R. W.

    2014-07-01

    To better understand the technology requirements for Uranus atmospheric entry probe, Entry Vehicle Technology project funded an internal study with a multidisciplinary team from NASA Ames, Langley and JPL. The results of this study are communicated.

  17. Impacts of aerosols on the chemistry of atmospheric trace gases: a case study of peroxides and HO2 radicals

    NASA Astrophysics Data System (ADS)

    Liang, H.; Chen, Z. M.; Huang, D.; Zhao, Y.; Li, Z. Y.

    2013-06-01

    Field measurements of atmospheric peroxides were obtained during the summer on two consecutive years over urban Beijing, and focused on the impacts of aerosols on the chemistry of peroxide compounds and hydroperoxyl radicals (HO2). The major peroxides were determined to be hydrogen peroxide (H2O2), methyl hydroperoxide (MHP), and peroxyacetic acid (PAA). A negative correlation was found between H2O2 and PAA in rainwater, providing evidence for a conversion between H2O2 and PAA in the aqueous phase. A standard gas phase chemistry model based on the NCAR Master Mechanism provided a good reproduction of the observed H2O2 profile on non-haze days but greatly overpredicted the H2O2 level on haze days. We attribute this overprediction to the reactive uptake of HO2 by the aerosols, since there was greatly enhanced aerosol loading and aerosol liquid water content on haze days. The discrepancy between the observed and modeled H2O2 can be diminished by adding to the model a newly proposed transition metal ion catalytic mechanism of HO2 in aqueous aerosols. This confirms the importance of the aerosol uptake of HO2 and the subsequent aqueous phase reactions in the reduction of H2O2. The closure of HO2 and H2O2 between the gas and aerosol phases suggests that the aerosols do not have a net reactive uptake of H2O2, because the conversion of HO2 to H2O2 on aerosols compensates for the H2O2 loss. Laboratory studies for the aerosol uptake of H2O2 in the presence of HO2 are urgently required to better understand the aerosol uptake of H2O2 in the real atmosphere.

  18. Impacts of aerosols on the chemistry of atmospheric trace gases: a case study of peroxides and HO2 radicals

    NASA Astrophysics Data System (ADS)

    Liang, H.; Chen, Z. M.; Huang, D.; Zhao, Y.; Li, Z. Y.

    2013-11-01

    Field measurements of atmospheric peroxides were obtained during the summer on two consecutive years over urban Beijing, which highlighted the impacts of aerosols on the chemistry of peroxide compounds and hydroperoxyl radicals (HO2). The major peroxides were determined to be hydrogen peroxide (H2O2), methyl hydroperoxide (MHP), and peroxyacetic acid (PAA). A negative correlation was found between H2O2 and PAA in rainwater, providing evidence for a conversion between H2O2 and PAA in the aqueous phase. A standard gas phase chemistry model based on the NCAR Master Mechanism provided a good reproduction of the observed H2O2 profile on non-haze days but greatly overpredicted the H2O2 level on haze days. We attribute this overprediction to the reactive uptake of HO2 by the aerosols, since there was greatly enhanced aerosol loading and aerosol liquid water content on haze days. The discrepancy between the observed and modeled H2O2 can be diminished by adding to the model a newly proposed transition metal ion catalytic mechanism of HO2 in aqueous aerosols. This confirms the importance of the aerosol uptake of HO2 and the subsequent aqueous phase reactions in the reduction of H2O2. The closure of HO2 and H2O2 between the gas and aerosol phases suggests that the aerosols do not have a net reactive uptake of H2O2, because the conversion of HO2 to H2O2 on aerosols compensates for the H2O2 loss. Laboratory studies for the aerosol uptake of H2O2 in the presence of HO2 are urgently required to better understand the aerosol uptake of H2O2 in the real atmosphere.

  19. Biogenic and anthropogenic isoprene in the near-surface urban atmosphere--a case study in Essen, Germany.

    PubMed

    Wagner, Patrick; Kuttler, Wilhelm

    2014-03-15

    Isoprene is emitted in large quantities by vegetation, exhaled by human beings and released in small quantities by road traffic. As a result of its high reactivity, isoprene is an important ozone precursor in the troposphere and can play a key role in atmospheric chemistry. Measurements of isoprene in urban areas in Central Europe are scarce. Thus, in Essen, Germany, the isoprene concentration was measured at various sites during different seasons using two compact online GC-PID systems. Isoprene concentrations were compared with those of benzene and toluene, which represent typical anthropogenic VOCs. In the summer, the diurnal variation in isoprene concentration was dependent on the biogenic emissions in the city. It was found that its maximum concentration occurred during the day, in contrast to the benzene and toluene concentrations. During the measurement period in the summer of 2012, the average hourly isoprene concentrations reached 0.13 to 0.17 ppb between 10 and 20 LST. At high air temperatures, the isoprene concentration exceeded the benzene and toluene concentrations at many of the sites. Isoprene became more important than toluene with regard to ozone formation in the city area during the afternoon hours of summer days with high air temperatures. This finding was demonstrated by the contributions to OH reactivity and ozone-forming potential. It contradicts the results of other studies, which were based on daily or seasonal average values. With an isoprene/benzene ratio of 0.02, the contribution of anthropogenic isoprene decreased substantially to a very low level during the last 20 years in Central Europe due to a strong reduction in road traffic emissions. In the vicinity of many people, isoprene concentrations of up to 0.54 ppb and isoprene/benzene ratios of up to 1.34 were found in the atmosphere due to isoprene exhaled by humans. PMID:24472568

  20. Does Cloud Computing in the Atmospheric Sciences Make Sense? A case study of hybrid cloud computing at NASA Langley Research Center

    NASA Astrophysics Data System (ADS)

    Nguyen, L.; Chee, T.; Minnis, P.; Spangenberg, D.; Ayers, J. K.; Palikonda, R.; Vakhnin, A.; Dubois, R.; Murphy, P. R.

    2014-12-01

    The processing, storage and dissemination of satellite cloud and radiation products produced at NASA Langley Research Center are key activities for the Climate Science Branch. A constellation of systems operates in sync to accomplish these goals. Because of the complexity involved with operating such intricate systems, there are both high failure rates and high costs for hardware and system maintenance. Cloud computing has the potential to ameliorate cost and complexity issues. Over time, the cloud computing model has evolved and hybrid systems comprising off-site as well as on-site resources are now common. Towards our mission of providing the highest quality research products to the widest audience, we have explored the use of the Amazon Web Services (AWS) Cloud and Storage and present a case study of our results and efforts. This project builds upon NASA Langley Cloud and Radiation Group's experience with operating large and complex computing infrastructures in a reliable and cost effective manner to explore novel ways to leverage cloud computing resources in the atmospheric science environment. Our case study presents the project requirements and then examines the fit of AWS with the LaRC computing model. We also discuss the evaluation metrics, feasibility, and outcomes and close the case study with the lessons we learned that would apply to others interested in exploring the implementation of the AWS system in their own atmospheric science computing environments.

  1. Studies of extended planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Hunten, D. M.

    1991-01-01

    The following topics are covered: (1) telescopic observations and analysis of planetary atmospheres (including the Moon and Mars) and the Io torus; (2) occultation observations; and (3) supporting laboratory studies.

  2. Atmospheric Entry Studies for Uranus

    NASA Astrophysics Data System (ADS)

    Agrawal, P.; Allen, G. A.; Hwang, H. H.; Marley, M. S.; McGuire, M. K.; Garcia, J. A.; Sklyanskiy, E.; Huynh, L. C.; Moses, R. W.

    2014-06-01

    To better understand the technology requirements for a Uranus atmospheric entry probe, an internal NASA study funded by ISPT program was conducted. The talk describes two different approaches to the planet: 1) direct ballistic entry and 2) Aerocapture.

  3. Evaluation of Pre-earthquake Atmospheric Signals and Their Connection with Earthquakes. Case Studies for Japan, Mexico and Taiwan

    NASA Astrophysics Data System (ADS)

    Ouzounov, D. P.; Pulinets, S. A.; Kafatos, M.

    2013-05-01

    We present observations of pre-earthquake lithosphere (ground air temperature and humidity measurements), atmosphere (satellite long-wavelength outgoing radiation -OLR- data from NOAA/POESS and NASA/AIRS satellites) and ionosphere signals (Total Electron Contents -TEC- collected from ground based GPS). These data were observed before major earthquakes in Japan, Taiwan and in Mexico. Our new approach is based of joint analysis on a joint analysis of these data. A sensor web analysis revealed atmosphere anomalies prior to most of these major earthquakes. Our retrospective analysis from Taiwan and Japan which includes 40 major earthquakes (M>5.9) covering the period 2005-2009 and over 20 earthquakes (M>6) over Mexico for the period of 2003-2012 revealed atmospheric anomalies. We found evidence for a systematic appearance of atmosphere- anomalies preceding 18 of the major events. Several days and up to 2 weeks before these earthquakes there were increases in OLR, ground air temperature, and ionospheric TEC measurements in proximity with the epicenters. We review these findings with respect to the theoretical model of Lithosphere-Atmosphere-Ionosphere coupling (Pulinets and Ouzounov, 2011) between the crust and the atmosphere/ ionosphere. We also discuss the skill -scores for several retrospective /prospective alerts and the practical usefulness of the presented methodology.

  4. An Observational Case Study on the Influence of Atmospheric Boundary-Layer Dynamics on New Particle Formation

    NASA Astrophysics Data System (ADS)

    Platis, Andreas; Altstädter, Barbara; Wehner, Birgit; Wildmann, Norman; Lampert, Astrid; Hermann, Markus; Birmili, Wolfram; Bange, Jens

    2016-01-01

    We analyze the influence of atmospheric boundary-layer development on new particle formation (NPF) during the morning transition. Continuous in-situ measurements of vertical profiles of temperature, humidity and aerosol number concentrations were quasi-continously measured near Melpitz, Germany, by unmanned aerial systems to investigate the potential connection between NPF and boundary-layer dynamics in the context of turbulence, temperature and humidity fluctuations. On 3 April 2014 high number concentrations of nucleation mode particles up to 6.0 × 10^4 cm^{-3} were observed in an inversion layer located about 450 m above ground level. The inversion layer exhibited a spatial temperature structure parameter C_T^2 15 times higher and a spatial humidity structure parameter C_q^2 5 times higher than in the remaining part of the vertical profile. The study provides hints that the inversion layer is responsible for creating favorable thermodynamic conditions for a NPF event. In addition, this layer showed a strong anti-correlation of humidity and temperature fluctuations. Using estimates of the turbulent mixing and dissipation rates, it is concluded that the downward transport of particles by convective mixing was also the reason of the sudden increase of nucleation mode particles measured on ground. This work supports the hypothesis that many of the NPF events that are frequently observed near the ground may, in fact, originate at elevated altitude, with newly formed particles subsequently being mixed down to the ground.

  5. Characteristics and mechanisms of the sudden warming events in the nocturnal atmospheric boundary layer: A case study using WRF

    NASA Astrophysics Data System (ADS)

    Ma, Yuanyuan; Yang, Yi; Hu, Xiao-Ming; Gan, Ruhui

    2015-10-01

    Although sudden nocturnal warming events near the earth's surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest China have not yet been investigated. The factors that lead to these warming events in such areas with their unique topography and climate remain not clear. To understand the formation mechanisms and associated thermal and dynamical features, a nocturnal warming event recorded in Gansu Province (northwest of the Loess Plateau) in June 2007 was investigated by using observations and model simulations with the Weather Research and Forecasting (WRF) model. Observations showed that this near-surface warming event lasted for 4 h and the temperature increased by 2.5°C. During this event, a decrease in humidity occurred simultaneously with the increase of temperature. The model simulation showed that the nocturnal warming was caused mainly by the transport of warmer and drier air aloft downward to the surface through enhanced vertical mixing. Wind shear played an important role in inducing the elevated vertical mixing, and it was enhanced by the continuous development of the atmospheric baroclinicity, which converted more potential energy to kinetic energy.

  6. New atmospheric sensor analysis study

    NASA Technical Reports Server (NTRS)

    Parker, K. G.

    1989-01-01

    The functional capabilities of the ESAD Research Computing Facility are discussed. The system is used in processing atmospheric measurements which are used in the evaluation of sensor performance, conducting design-concept simulation studies, and also in modeling the physical and dynamical nature of atmospheric processes. The results may then be evaluated to furnish inputs into the final design specifications for new space sensors intended for future Spacelab, Space Station, and free-flying missions. In addition, data gathered from these missions may subsequently be analyzed to provide better understanding of requirements for numerical modeling of atmospheric phenomena.

  7. Climate and atmospheric modeling studies

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The climate and atmosphere modeling research programs have concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three-dimensional global model, and an upper ocean model. Principal applications were the study of the impact of CO2, aerosols, and the solar 'constant' on climate.

  8. THE USE OF MODELED ATMOSPHERIC WIND TRAJECTORIES TO DETERMINE POTENTIAL DOWNWIND GENE FLOW; A CASE STUDY USING GM-BENTGRASS

    EPA Science Inventory

    The down-wind dispersal of pollen and the airborne spread of seed are affected by the size, shape and weight of the particles and by the strength, buoyancy and direction of surface winds. An atmospheric model (HYSPLIT model: www.arl.noaa.gov\\ready.html) was used to reconstruct w...

  9. Aromatic hydrocarbons in the atmospheric environment - Part II: univariate and multivariate analysis and case studies of indoor concentrations

    NASA Astrophysics Data System (ADS)

    Ilgen, Elke; Levsen, Karsten; Angerer, Jürgen; Schneider, Peter; Heinrich, Joachim; Wichmann, H.-Erich

    The concentrations of the aromatic hydrocarbons benzene, toluene, ethylbenzene and the isomeric xylenes (BTEX) have been determined in the indoor air of 115 private non-smoker homes (˜380 individual rooms) situated in areas with an extreme traffic situation, i.e. in city streets (street canyons) with high traffic density and in rural areas with hardly any traffic at all. The influence of the traffic on the indoor concentration was apparent in the high traffic area. In order to identify other factors influencing the BTEX concentrations, the data and additional questionnaires were analyzed by univariate and multivariate analysis. The analysis was supplemented by some case studies. It is shown that meteorology (the seasons), the type of room (e.g. living room versus bedroom), the ventilation and, in particular, garages in the house strongly influence the indoor concentration of BTEX. Thus, the indoor BTEX level is significantly higher in winter than in summer. Moreover, garages with a connecting door to the living quarters lead to high indoor concentrations of aromatic hydrocarbons in these rooms. In addition, the storage of solvents and hobby materials, and also the presence of smoking guests increase the BTEX level. If rooms are directly heated by coal or wood, the BTEX level is higher compared to the use of gas heating. Surprisingly, no correlation was found between the building materials used and the BTEX level. Case studies were carried out for two homes with an integrated garage (and a connecting door to the living rooms) and for seven homes where redecoration work was carried out during sampling. In both instances, a pronounced increase was observed in the BTEX concentration.

  10. Case Studies

    ERIC Educational Resources Information Center

    Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

    2007-01-01

    This article presents two case studies using online surveys for evaluation. The authors begin with an example of a needs assessment survey designed to measure the amount of help new students at a university require in their first year. They then discuss the follow-up survey conducted by the same university to measure the effectiveness of the…

  11. The impact of polybrominated diphenyl ether prohibition: A case study on the atmospheric levels in China, Japan and South Korea

    NASA Astrophysics Data System (ADS)

    Li, Qilu; Li, Jun; Chaemfa, Chakra; Zhang, Gan; Kobara, Yuso; Nam, Jae-Jak; Jones, Kevin C.

    2014-06-01

    The atmosphere is an important medium which could directly reflect the changes of pollutant sources. Worldwide, the commercial products of polybrominated diphenyl ethers (PBDEs) have been officially restricted and subsequently prohibited. For the purpose of evaluating their concentration after prohibition, passive air samplers (PASs) were therefore deployed again across the East Asia during two periods in 2008 after the initial deployment 4 years ago. When compared with the data in 2004, the atmospheric concentrations of PBDEs have declined significantly. Spatially, the PBDE level in China was still the highest, with a mean value of 15.4 pg m- 3, and in Japan was the lowest (2.47 ± 1.12 pg m- 3) in the East Asia. Moreover, the relatively high concentrations were observed at sites where there are electronic or e-waste recycling industries, and this is particularly true in China, suggesting that illegally imported e-waste is still a typical source of PBDEs in this region.

  12. Use of health effect risk estimates and uncertainty in formal regulatory proceedings: a case study involving atmospheric particulates

    SciTech Connect

    Habegger, L.J.; Oezkaynak, A.H.

    1984-01-01

    Coal combustion particulates are released to the atmosphere by power plants supplying electrical to the nuclear fuel cycle. This paper presents estimates of the public health risks associated with the release of these particulates at a rate associated with the annual nuclear fuel production requirements for a nuclear power plan. Utilization of these risk assessments as a new component in the formal evaluation of total risks from nuclear power plants is discussed. 23 references, 3 tables.

  13. Studies of Tenuous Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Combi, Michael R.

    1998-01-01

    The final report includes an overall project overview as well as scientific background summaries of dust and sodium in comets, and tenuous atmospheres of Jupiter's natural satellites. Progress and continuing work related to dust coma and tenuous atmospheric studies are presented. Also included are published articles written during the course of the report period. These are entitled: (1) On Europa's Magnetospheric Interaction: An MHD Simulation; (2) Dust-Gas Interrelations in Comets: Observations and Theory; and (3) Io's Plasma Environment During the Galileo Flyby: Global Three Dimensional MHD Modeling with Adaptive Mesh Refinement.

  14. New atmospheric sensor analysis study

    NASA Technical Reports Server (NTRS)

    Parker, K. G.

    1985-01-01

    A progress report of the activities pertaining to the Atmospheric Sensor Analysis Study is given. The current revision of the Perkin-Elmer Operating System OS/32 MT 7.2.1 was installed on the Atmospheric Modeling and Simulation System (AMASS). This software appears to offer a means of distributing disc storage among the user community in a more optimal manner than previously available using the file manager. Next Generation Weather Radar (NEXRAD) software has been received from the National Severe Storms Laboratory (NSSL) and has been loaded onto the Perkin-Elmer. Extensive modifications will be required to permit the software to be compatible with the operating system.

  15. Parameterizing atmosphere-land surface exchange for climate models with satellite data: A case study for the Southern Great Plains CART site

    SciTech Connect

    Gao, W.

    1994-01-01

    High-resolution satellite data provide detailed, quantitative descriptions of land surface characteristics over large areas so that objective scale linkage becomes feasible. With the aid of satellite data, Sellers et al. and Wood and Lakshmi examined the linearity of processes scaled up from 30 m to 15 km. If the phenomenon is scale invariant, then the aggregated value of a function or flux is equivalent to the function computed from aggregated values of controlling variables. The linear relation may be realistic for limited land areas having no large surface contrasts to cause significant horizontal exchange. However, for areas with sharp surface contrasts, horizontal exchange and different dynamics in the atmospheric boundary may induce nonlinear interactions, such as at interfaces of land-water, forest-farm land, and irrigated crops-desert steppe. The linear approach, however, represents the simplest scenario, and is useful for developing an effective scheme for incorporating subgrid land surface processes into large-scale models. Our studies focus on coupling satellite data and ground measurements with a satellite-data-driven land surface model to parameterize surface fluxes for large-scale climate models. In this case study, we used surface spectral reflectance data from satellite remote sensing to characterize spatial and temporal changes in vegetation and associated surface parameters in an area of about 350 {times} 400 km covering the southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of the US Department of Energy`s Atmospheric Radiation Measurement (ARM) Program.

  16. Biomass burning influences on atmospheric composition: A case study to assess the impact of aerosol data assimilation

    NASA Astrophysics Data System (ADS)

    Keslake, Tim; Chipperfield, Martyn; Mann, Graham; Flemming, Johannes; Remy, Sam; Dhomse, Sandip; Morgan, Will

    2016-04-01

    The C-IFS (Composition Integrated Forecast System) developed under the MACC series of projects and to be continued under the Copernicus Atmospheric Monitoring System, provides global operational forecasts and re-analyses of atmospheric composition at high spatial resolution (T255, ~80km). Currently there are 2 aerosol schemes implemented within C-IFS, a mass-based scheme with externally mixed particle types and an aerosol microphysics scheme (GLOMAP-mode). The simpler mass-based scheme is the current operational system, also used in the existing system to assimilate satellite measurements of aerosol optical depth (AOD) for improved forecast capability. The microphysical GLOMAP scheme has now been implemented and evaluated in the latest C-IFS cycle alongside the mass-based scheme. The upgrade to the microphysical scheme provides for higher fidelity aerosol-radiation and aerosol-cloud interactions, accounting for global variations in size distribution and mixing state, and additional aerosol properties such as cloud condensation nuclei concentrations. The new scheme will also provide increased aerosol information when used as lateral boundary conditions for regional air quality models. Here we present a series of experiments highlighting the influence and accuracy of the two different aerosol schemes and the impact of MODIS AOD assimilation. In particular, we focus on the influence of biomass burning emissions on aerosol properties in the Amazon, comparing to ground-based and aircraft observations from the 2012 SAMBBA campaign. Biomass burning can affect regional air quality, human health, regional weather and the local energy budget. Tropical biomass burning generates particles primarily composed of particulate organic matter (POM) and black carbon (BC), the local ratio of these two different constituents often determining the properties and subsequent impacts of the aerosol particles. Therefore, the model's ability to capture the concentrations of these two

  17. Atmospheric Entry Studies for Uranus

    NASA Technical Reports Server (NTRS)

    Agrawal, Parul; Allen, Gary A.; Hwang, Helen; Prabhu, Dinesh; Aliaga, Jose; Marley, Mark; McGuire, Kathy; Huynh, Loc; Garcia, Joseph; Moses, Robert; Winski, Rick; Skylanskiy, Evgeniy

    2013-01-01

    The Objectives of this work are: 1) Establish a range of probe atmospheric entry environments based on the Uranus Flagship mission outlined in the Planetary Science Decadal Survey for two launch windows: Year 2021 and 2034. 2) Define Uranus entry trade space by performing parametric studies, by varying vehicle mass and size and entry Flight Path Angle (FPA). 3) Investigate various trajectory options, including direct ballistic entry and aero-capture entry. 4) Identify entry technologies that could be leveraged to enable a viable mission to Uranus that meets science objectives.

  18. Atmospheric correction for Landsat 8 over case 2 waters

    NASA Astrophysics Data System (ADS)

    Concha, Javier A.; Schott, John R.

    2015-09-01

    The most interaction between humankind and water occurs in coastal and inland waters (Case 2 waters) at a scale of tens or hundred of meters, but there is not yet an ocean color product at this spatial scale. Landsat 8 is a promising candidate to address the remote sensing of these kinds of waters due to its improved signal-to-noise ratio (SNR), spectral resolution, 12-bit quantization, and high spatial resolution. Standard atmospheric correction algorithms developed for heritage ocean color instruments (e.g. MODIS, SeaWiFS) require a sufficient SNR in two bands where the water-leaving signal is negligible, which is not always possible, particularly for Landsat 8's bands. The model-based empirical line method (MoB-ELM) atmospheric algorithm for Landsat 8 imagery does not rely on this assumption. In this work, we evaluate the performance of this algorithm. We compare the MoB-ELM algorithm with in situ data and with three standard atmospheric correction algorithms. The results from our algorithm are comparable with the standard algorithms in some bands when comparing remote-sensing reflectances. When compared with in situ remote-sensing reflectance, the MoB-ELM perform similar to the standard algorithm in most cases. A comparison of retrieved chlorophyll-a concentration was perform as well, showing that the MoB- ELM outperforms the rest at high concentrations commonly found in Case 2 waters. These results show that our atmospheric correction algorithm allows one to use Landsat 8 to study Case 2 waters as an alternative to heritage ocean color satellites.

  19. Case Study: Testing with Case Studies

    ERIC Educational Resources Information Center

    Herreid, Clyde Freeman

    2015-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses using case studies to test for knowledge or lessons learned.

  20. Study of Atmospheric Nitric Oxide

    NASA Technical Reports Server (NTRS)

    Dalgarno, A.

    1998-01-01

    We investigated the contribution of energetic nitrogen atoms to the production of nitric oxide in the thermosphere and their influence on the infrared emission spectrum. The nitric oxide molecules are important contributors to the cooling of the atmosphere. We first pointed out that in determining the energy distribution of the nitrogen atoms, it is important to take into account the thermal motion of the atmospheric gases. It had been ignored in all earlier studies. The source spectra are broadened considerably by the center of mass motion of the reactants. We worked out the consequences for the production of nitric oxide at night, using as sources of energetic N atoms, NO(+) + e yield N + O, N(D-2) + O yield N + O. The high energy tail is enhanced by orders of magnitude. We had earlier suggested (Sharma et al. 1993) that the reaction of energetic nitrogen atoms with O2 was responsible for the rotationally enhanced NO identified in the infrared spectrum. Our calculations provided quantitative confirmation of the suggestion. We proceeded to explore the validity of another approximation used in earlier analyses, the hard sphere approximation for the energy loss in elastic collisions. We carried out precise quantum mechanical calculations of the elastic 2 differential scattering of nitrogen atoms in collisions with oxygen atoms and showed that although the hard sphere approximation was nowhere of high precision, reasonable results could be obtained with an effective cross section of 6 x 10(exp 15)sq cm. We also initiated a program to include inelastic energy loss processes in the determination of the energy distribution function. We began a calculation of the rotation and vibrational excitation cross sections of molecular nitrogen and nitrogen atoms and developed a method for including inelastic energy loss as a function of scattering angle in the Boltzmann equation. A procedure for obtaining the solution of the Boltzman equation was worked out.

  1. Scientific program in planetary atmospheric studies

    NASA Technical Reports Server (NTRS)

    Broadfoot, A. L.

    1983-01-01

    The Voyager encounters with Jupiter led to two main areas of investigation: (1) the definition of the structure and composition of the upper atmosphere and the interaction of the magnetosphere and atmosphere, and (2) the study of the plasma torus using the EUV (Extreme Ultraviolet) data in conjunction with ground-based and in-situ measurements. In the course of these investigations, the atmosphere studies were extended to a comparative study with the bound atmospheres of Saturn and Titan; and the torus study expanded to include the extended atmospheres of Titan (the H torus) and the rings of Saturn.

  2. Ocean tide, Baltic Sea and atmospheric loading model tilt comparisons with interferometric geodynamic tilt observation - case study at Lohja2 geodynamic station, southern Finland

    NASA Astrophysics Data System (ADS)

    Ruotsalainen, H.; Nordman, M.; Virtanen, J.; Virtanen, H.

    2015-12-01

    Ocean loading models, Baltic Sea loading and atmospheric loading tilt models are compared with the long interferometric water level tilt meter recordings at the Lohja2 geodynamics laboratory in southern Finland. The tilt meter shows a high response to different loading phenomena, and it can be used to study earth dynamics, earth structure modeling, and 2D surface mass loading model validation. Special attention is paid on the Baltic Sea and atmospheric loading tilt oscillations. The four ocean loading models used show deviating values compared to the measured earth tide tilt parameters. The CSR4.0 ocean loading model fits best to analyzed tidal tilt observations at the site. After reductions of earth tides, ocean, the Baltic Sea and atmospheric loading tilt, the largest residual tilt signals are located in frequency bands below 0.5 cycle/day.

  3. NASA Planetary Astronomy Lunar Atmospheric Imaging Study

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan

    1996-01-01

    Authors have conducted a program of research focused on studies of the lunar atmosphere. Also present preliminary results of an ongoing effort to determine the degree that metal abundances in the lunar atmosphere are stoichiometric, that is, reflective of the lunar surface composition. We make the first-ever mid-ultraviolet spectroscopic search for emission from the lunar atmosphere.

  4. Mosses as an integrating tool for monitoring PAH atmospheric deposition: comparison with total deposition and evaluation of bioconcentration factors. A year-long case-study.

    PubMed

    Foan, Louise; Domercq, Maria; Bermejo, Raúl; Santamaría, Jesús Miguel; Simon, Valérie

    2015-01-01

    Polycyclic aromatic hydrocarbon (PAH) atmospheric deposition was evaluated at a remote site in Northern Spain using moss biomonitoring with Hylocomium splendens (Hedw.) Schimp., and by measuring the total deposition fluxes of PAHs. The year-long study allowed seasonal variations of PAH content in mosses to be observed, and these followed a similar trend to those of PAH fluxes in total deposition. Generally, atmospheric deposition of PAHs is greater in winter than in summer, due to more PAH emissions from domestic heating, less photoreactivity of the compounds, and intense leaching of the atmosphere by wet deposition. However, fractionation of these molecules between the environmental compartments occurs: PAH fluxes in total deposition and PAH concentrations in mosses are correlated with their solubility (r=0.852, p<0.01) and lipophilic properties (KOW, r=0.768, p<0.01), respectively. This annual study therefore showed that atmospheric PAH fluxes can be estimated with moss biomonitoring data if the bioconcentration or 'enriching' factors are known. PMID:25084064

  5. Southeast Atmosphere Studies Workshop 2015

    EPA Science Inventory

    Concentrations of atmospheric trace species in the United States have changed dramatically over the past several decades in response to pollution control strategies, shifts in domestic energy policy, and economic development (and resulting emission changes) elsewhere in the world...

  6. Pre-earthquake signatures in atmosphere/ionosphere and their potential for short-term earthquake forecasting. Case studies for 2015

    NASA Astrophysics Data System (ADS)

    Ouzounov, Dimitar; Pulinets, Sergey; Davidenko, Dmitry; Hernández-Pajares, Manuel; García-Rigo, Alberto; Petrrov, Leonid; Hatzopoulos, Nikolaos; Kafatos, Menas

    2016-04-01

    We are conducting validation studies on temporal-spatial pattern of pre-earthquake signatures in atmosphere and ionosphere associated with M>7 earthquakes in 2015. Our approach is based on the Lithosphere Atmosphere Ionosphere Coupling (LAIC) physical concept integrated with Multi-sensor-networking analysis (MSNA) of several non-correlated observations that can potentially yield predictive information. In this study we present two type of results: 1/ prospective testing of MSNA-LAIC for M7+ in 2015 and 2:/ retrospective analysis of temporal-spatial variations in atmosphere and ionosphere several days before the two M7.8 and M7.3 in Nepal and M8.3 Chile earthquakes. During the prospective test 18 earthquakes M>7 occurred worldwide, from which 15 were alerted in advance with the time lag between 2 up to 30 days and with different level of accuracy. The retrospective analysis included different physical parameters from space: Outgoing long-wavelength radiation (OLR obtained from NPOES, NASA/AQUA) on the top of the atmosphere, Atmospheric potential (ACP obtained from NASA assimilation models) and electron density variations in the ionosphere via GPS Total Electron Content (GPS/TEC). Concerning M7.8 in Nepal of April 24, rapid increase of OLR reached the maximum on April 21-22. GPS/TEC data indicate maximum value during April 22-24 periods. Strong negative TEC anomaly was detected in the crest of EIA (Equatorial Ionospheric Anomaly) on April 21st and strong positive on April 24th, 2015. For May 12 M7.3 aftershock similar pre- earthquake patterns in OLR and GPS/TEC were observed. Concerning the M8.3 Chile of Sept 16, the OLR strongest transient feature was observed of Sept 12. GPS/TEC analysis data confirm abnormal values on Sept 14. Also on the same day the degradation of EIA and disappearance of the crests of EIA as is characteristic for pre-dawn and early morning hours (11 LT) was observed. On Sept 16 co-seismic ionospheric signatures consistent with defined circular

  7. Case Study: Writing a Journal Case Study

    ERIC Educational Resources Information Center

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

  8. Atmospheric Gravity Waves (AGWs) as the driver of seismo-ionospheric coupling: recent major earthquakes of Nepal and Imphal - case study

    NASA Astrophysics Data System (ADS)

    Chakraborty, Suman; Chakrabarti, Sandip Kumar; Sasmal, Sudipta

    2016-07-01

    An important channel of the lithosphere-atmosphere-ionosphere coupling (LAIC) is the acoustic and gravity wave channel where the atmospheric gravity waves (AGW) play the most important part. Atmospheric waves are excited due to seismic gravitational vibrations before earthquakes and their effects on the atmosphere are the sources for seismo-ionospheric coupling which are manifested as perturbations in Very Low Frequency (VLF)/Low Frequency (LF) signal (amplitude/phase). For our study, we chose the recent major earthquakes that took place in Nepal and Imphal. The Nepal earthquake occurred on 12th May, 2015 at 12:50 pm local time (07:05 UTC) with Richter scale magnitude of M = 7.3 and depth 10 km (6.21 miles) at southeast of Kodari. The Imphal earthquake occurred on 4th January, 2016 at 4:35 am local time (23:05 UTC , 3rd January, UTC) with Richter scale magnitude of M = 6.7 and depth 55 km (34.2 miles). The data has been collected from Ionospheric and Earthquake Research Centre (IERC) of Indian Centre for Space Physics (ICSP) transmitted from JJI station of Japan. We performed both Fast Fourier Transform (FFT) and wavelet analysis on the VLF data for a couple of days before and after the major earthquakes. For both earthquakes, we observed wave like structures with periods of almost an hour before and after the earthquake day. The wave like oscillations after the earthquake may be due to the aftershock effects. We also observed that the amplitude of the wave like structures depends on the location of the epicenter between the transmitting and the receiving points and also on the depth of the earthquake.

  9. Analysis of vegetation by the application of a physically-based atmospheric correction algorithm to OLI data: a case study of Leonessa Municipality, Italy

    NASA Astrophysics Data System (ADS)

    Mei, Alessandro; Manzo, Ciro; Petracchini, Francesco; Bassani, Cristiana

    2016-04-01

    Remote sensing techniques allow to estimate vegetation parameters related to large areas for forest health evaluation and biomass estimation. Moreover, the parametrization of specific indices such as Normalized Difference Vegetation Index (NDVI) allows to study biogeochemical cycles and radiative energy transfer processes between soil/vegetation and atmosphere. This paper focuses on the evaluation of vegetation cover analysis in Leonessa Municipality, Latium Region (Italy) by the use of 2015 Landsat 8 applying the OLI@CRI (OLI ATmospherically Corrected Reflectance Imagery) algorithm developed following the procedure described in Bassani et al. 2015. The OLI@CRI is based on 6SV radiative transfer model (Kotchenova et al., 2006) ables to simulate the radiative field in the atmosphere-earth coupled system. NDVI was derived from the OLI corrected image. This index, widely used for biomass estimation and vegetation analysis cover, considers the sensor channels falling in the near infrared and red spectral regions which are sensitive to chlorophyll absorption and cell structure. The retrieved product was then spatially resampled at MODIS image resolution and then validated by the NDVI of MODIS considered as reference. The physically-based OLI@CRI algorithm also provides the incident solar radiation at ground at the acquisition time by 6SV simulation. Thus, the OLI@CRI algorithm completes the remote sensing dataset required for a comprehensive analysis of the sub-regional biomass production by using data of the new generation remote sensing sensor and an atmospheric radiative transfer model. If the OLI@CRI algorithm is applied to a temporal series of OLI data, the influence of the solar radiation on the above-ground vegetation can be analysed as well as vegetation index variation.

  10. Studies in upper and lower atmosphere coupling

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Rice, C. J.; Sharp, L. R.

    1979-01-01

    The theoretical and data-analytic work on upper and lower atmosphere coupling performed under a NASA Headquarters contract during the period April 1978 to March 1979 are summarized. As such, this report is primarily devoted to an overview of various studies published and to be published under this contract. Individual study reports are collected as exhibits. Work performed under the subject contract are in the following four areas of upper-lower atmosphere coupling: (1) Magnetosphere-ionosphere electrodynamic coupling in the aurora; (2) Troposphere-thermosphere coupling; (3) Ionosphere-neutral-atmosphere coupling; and (4) Planetary wave dynamics in the middle atmosphere.

  11. Studies of planetary upper atmospheres through occultations

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.

    1982-01-01

    The structure, composition, dynamics and energy balance of planetary upper atmospheres through interpretation of steller occultation data from Uranus is discussed. The wave-optical problem of modelling strong scintillation for arbitrary turbulent atmospheres is studied, as well as influence of turbulence. It was concluded that quasi-global features of atmospheric structure are accurately determined by numerical inversion. Horizontally inhomogeneous structures are filtered out and have little effect on temperature profiles.

  12. Density Imaging of Puy de Dôme Volcano with Atmospheric Muons in French Massif Central as a Case Study for Volcano Muography

    NASA Astrophysics Data System (ADS)

    Carloganu, Cristina; Le Ménédeu, Eve

    2016-04-01

    High energy atmospheric muons have high penetration power that renders them appropriate for geophysical studies. Provided the topography is known, the measurement of the muon flux transmittance leads in an univoque way to 2D density mapping (so called radiographic images) revealing spatial and possibly also temporal variations. Obviously, several radiographic images could be combined into 3D tomographies, though the inverse 3D problem is generally ill-posed. The muography has a high potential for imaging remotely (from kilometers away) and with high resolution (better than 100 mrad2) volcanoes. The experimental and methodological task is however not straightforward since atmospheric muons have non trivial spectra that fall rapidly with muon energy. As shown in [Ambrosino 2015] successfully imaging km-scale volcanoes remotely requires state-of-the art, high-resolution and large-scale muon detectors. This contribution presents the geophysical motivation for muon imaging as well as the first quantitative density radiographies of Puy de Dôme volcano obtained by the TOMUVOL collaboration using a highly segmented muon telescope based on Glass Resistive Plate Chambers. In parallel with the muographic studies, the volcano was imaged through standard geophysical methods (gravimetry, electrical resistivity) [Portal 2013] allowing in depth comparisons of the different methods. Ambrosino, F., et al. (2015), Joint measurement of the atmospheric muon flux through the Puy de Dôme volcano with plastic scintillators and Resistive Plate Chambers detectors, J. Geophys. Res. Solid Earth, 120, doi:10.1002/2015JB011969 A. Portal et al (2013) , "Inner structure of the Puy de Dme volcano: cross-comparison of geophysical models (ERT, gravimetry, muon imaging)", Geosci. Instrum. Method. Data Syst., 2, 47-54, 2013

  13. A case study of effects of atmospheric boundary layer turbulence, wind speed, and stability on wind farm induced temperature changes using observations from a field campaign

    NASA Astrophysics Data System (ADS)

    Xia, Geng; Zhou, Liming; Freedman, Jeffrey M.; Roy, Somnath Baidya; Harris, Ronald A.; Cervarich, Matthew Charles

    2016-04-01

    Recent studies using satellite observations show that operational wind farms in west-central Texas increase local nighttime land surface temperature (LST) by 0.31-0.70 °C, but no noticeable impact is detected during daytime, and that the diurnal and seasonal variations in the magnitude of this warming are likely determined by those in the magnitude of wind speed. This paper further explores these findings by using the data from a year-long field campaign and nearby radiosonde observations to investigate how thermodynamic profiles and surface-atmosphere exchange processes work in tandem with the presence of wind farms to affect the local climate. Combined with satellite data analyses, we find that wind farm impacts on LST are predominantly determined by the relative ratio of turbulence kinetic energy (TKE) induced by the wind turbines compared to the background TKE. This ratio explains not only the day-night contrast of the wind farm impact and the warming magnitude of nighttime LST over the wind farms, but also most of the seasonal variations in the nighttime LST changes. These results indicate that the diurnal and seasonal variations in the turbine-induced turbulence relative to the background TKE play an essential role in determining those in the magnitude of LST changes over the wind farms. In addition, atmospheric stability determines the sign and strength of the net downward heat transport as well as the magnitude of the background TKE. The study highlights the need for better understanding of atmospheric boundary layer and wind farm interactions, and for better parameterizations of sub-grid scale turbulent mixing in numerical weather prediction and climate models.

  14. Parametric study of the Venus atmospheric superrotation

    NASA Astrophysics Data System (ADS)

    Takagi, Masahiro; Matsuda, Yoshihisa

    2012-07-01

    It has been suggested by Takagi and Matsuda (2007) that the Venus atmospheric superrotation can be generated and maintained by the thermal tides excited by the solar heating at the cloud levels. The superrotation generated by the thermal tide mechanism is supposed to be sensitive to the static stability, initial conditions, vertical distribution of the solar heating, and so on. In the present study, we focus on how the superrotation maintained by the thermal tide mechanism depends on the static stability. The preliminary result shows that the superrotation is maintained in the cases of large static stability, and it fades out with time in the cases of small static stability. The difference may by explained by the dispersion relation of the gravity wave and the thermodynamic balance of the semidiurnal tide. It is also shown that the superrotation faster than 200 m/s is generated in the case included the mean zonal component of the solar heating. It is implied that the deceleration effect of the mean zonal flow due to the thermal tide is canceled by the vertical advection of negative dU/dz above the cloud level, and the momentum is actively exchanged between the cloud and the ground levels because of the vital semidiurnal tide.

  15. Space-borne Observations of Atmospheric Pre-Earthquake Signals in Seismically Active Areas: Case Study for Greece 2008-2009

    NASA Technical Reports Server (NTRS)

    Ouzounov, D. P.; Pulinets, S. A.; Davidenko, D. A.; Kafatos, M.; Taylor, P. T.

    2013-01-01

    We are conducting theoretical studies and practical validation of atm osphere/ionosphere phenomena preceding major earthquakes. Our approach is based on monitoring of two physical parameters from space: outgoi ng long-wavelength radiation (OLR) on the top of the atmosphere and e lectron and electron density variations in the ionosphere via GPS Tot al Electron Content (GPS/TEC). We retrospectively analyzed the temporal and spatial variations of OLR an GPS/TEC parameters characterizing the state of the atmosphere and ionosphere several days before four m ajor earthquakes (M>6) in Greece for 2008-2009: M6.9 of 02.12.08, M6. 2 02.20.08; M6.4 of 06.08.08 and M6.4 of 07.01.09.We found anomalous behavior before all of these events (over land and sea) over regions o f maximum stress. We expect that our analysis reveal the underlying p hysics of pre-earthquake signals associated with some of the largest earthquakes in Greece.

  16. Aerosol impact on atmospheric meso-scale circulation over the Baltic region: A HARMONIE model case study and verification versus radar data

    NASA Astrophysics Data System (ADS)

    Palamarchuk, Iuliia; Mahura, Alexander; Ivanov, Sergiy; Ruban, Igor; Pavlova, Hanna

    2015-04-01

    An important goal in operational weather forecasting is an accurate prediction of precipitation on meso-scales. This demands, among the others, detailed representation of aerosol impact on the troposphere. Various direct, semi-direct and indirect effects of aerosols lead to significant changes in amount and distribution of precipitation, especially for weak patterns. Features of the atmosphere sensitivity to aerosols is studied employing the HARMONIE (Hirlam Aladin Regional/Meso-scale Operational NWP In Europe) model. Numerical experiments are performed for the Baltic region during the BaltRad experiment (August 2010). The focus of the study is the life-time of convective cells along with feedbacks from aerosols toward meteorological parameters, physical and dynamical mechanisms responsible for developing of precipitation forecast features, direct and indirect aerosol effects. Numerical results are verified by comparing model microphysics fields versus radar reflectivity.

  17. Case Study Teaching

    ERIC Educational Resources Information Center

    Herreid, Clyde Freeman

    2011-01-01

    This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

  18. First simultaneous space measurements of atmospheric pollutants in the boundary layer from IASI: a case study in the North China Plain

    NASA Astrophysics Data System (ADS)

    Boynard, Anne; Clerbaux, Cathy; Clarisse, Lieven; Safieddine, Sarah; Pommier, Matthieu; Van Damme, Martin; Bauduin, Sophie; Oudot, Charlotte; Hadji-Lazaro, Juliette; Hurtmans, Daniel; Coheur, Pierre-François

    2014-05-01

    An extremely severe and persistent smog episode occurred in January 2013 over China. The levels of air pollution have been dangerously high, reaching 40 times recommended safety levels and have affected health of millions of people. China faced one of the worst periods of air quality in recent history and drew worldwide attention. This pollution episode was caused by the combination of anthropogenic emissions and stable meteorological conditions (absence of wind and temperature inversion) that trapped pollutants in the boundary layer. To characterize this episode, we used the IASI (Infrared Atmospheric Sounding Interferometer) instrument onboard the MetOp-A platform. IASI observations show high concentrations of key trace gases such as carbon monoxide (CO), sulfur dioxide (SO2) and ammonia (NH3) along with ammonium sulfate aerosol. We show that IASI is able to detect boundary layer pollution in case of large negative thermal contrast combined with high levels of pollution. Our findings demonstrate the ability of thermal infrared instrument such as IASI to monitor boundary layer pollutants, which can support air quality evaluation and management.

  19. Radon in atmospheric studies: a review

    SciTech Connect

    Wilkening, M.

    1981-01-01

    The distribution of the isotopes of radon in space and time, their physical characteristics, and their behavior in the dynamics of the atmosphere have presented challenges for many decades. /sup 220/Rn, /sup 222/Rn and their daughters furnish a unique set of tracers for the study of transport and mixing processes in the atmosphere. Appropriate applications of turbulent diffusion theory yield general agreement with measured profiles. Diurnal and seasonal variations follow patterns set by consideration of atmospheric stability. /sup 222/Rn has been used successfully in recent studies of nocturnal drainage winds and cumulus convection. Good results have been obtained using /sup 222/Rn and its long-lived /sup 210/Pb daughter as tracers in the study of continent-to-ocean and ocean-to-continent air mass trajectories, /sup 220/Rn (thoron) because of its short half-life of only 55 seconds has been used to measure turbulent diffusion within the first few meters of the earth's surface and to study the influence of meteorological variables on the rate of exhalation from the ground. Radon daughters attach readily to atmospheric particulate matter which makes it possible to study these aerosols with respect to size spectra, attachment characteristics, removal by gravitation and precipitation, and residence times in the troposphere. The importance of ionization by radon and its daughters in the lower atmosphere and its effect on atmospheric electrical parameters is well known. Knowledge of the mobility and other characteristics of radon daughter ions has led to applications in the study of atmospheric electrical environments under fair weather and thunderstorm conditions and in the formation of condensation nuclei. The availability of increasingly sophisticated analytical tools and atmospheric measurement systems can be expected to add much to our understanding of radon and its daughters as trace components of the atmospheric environment in the years ahead.

  20. Angular momentum exchange among the solid Earth, atmosphere, and oceans: A case study of the 1982-1983 El Nino event

    NASA Technical Reports Server (NTRS)

    Dickey, J. O.; Marcus, S. L.; Hide, R.; Eubanks, T. M.; Boggs, D. H.

    1994-01-01

    The 1982-1983 El Nino/Southern Oscillation (ENSO) event was accompanied by the largest interannual variation in the Earth's rotation rate on record. In this study we demonstrate that atmospheric forcing was the dominant cause for this rotational anomaly, with atmospheric angular momentum (AAM) integrated from 1000 to 1 mbar (troposphere plus stratosphere) accounting for up to 92% of the interannual variance in the length of day (LOD). Winds between 100 and 1 mbar contributed nearly 20% of the variance explained, indicating that the stratosphere can play a significant role in the Earth's angular momentum budget on interannual time scales. Examination of LOD, AAM, and Southern Oscillation Index (SOI) data for a 15-year span surrounding the 1982-1983 event suggests that the strong rotational response resulted from constructive interference between the low-frequency (approximately 4-6 year) and quasi-biennial (approximately 2-3 year) components of the ENSO phenomenon, as well as the stratospheric Quasi-Biennial Oscillation (QBO). Sources of the remaining LOD discrepancy (approximately 55 and 64 microseconds rms residual for the European Centre for Medium-Range Forecasting (EC) and U.S. National Meteorological Center (NMC) analyses) are explored; noise and systematic errors in the AAM data are estimated to contribute 18 and 33 microseconds, respectively, leaving a residual (rms) of 40 (52) microseconds unaccounted for by the EC (NMC) analysis. Oceanic angular momentum contributions (both moment of inertia changes associated with baroclinic waves and motion terms) are shown to be candidates in closing the interannual axial angular momentum budget.

  1. Diagnosing the Nature of Land-Atmosphere Coupling: A Case Study of Dry/Wet Extremes in the U. S. Southern Great Plains

    NASA Technical Reports Server (NTRS)

    Santanello, Joseph A. Jr.; Peters-Lidard, Christa D.; Kennedy, Aaron; Kumar, Sujay V.

    2012-01-01

    Land-atmosphere (L-A) interactions play a critical role in determining the diurnal evolution of land surface and planetary boundary layer (PBL) temperature and moisture states and fluxes. In turn, these interactions regulate the strength of the connection between surface moisture and precipitation in a coupled system. To address model deficiencies, recent studies have focused on development of diagnostics to quantify the strength and accuracy of the land- PBL coupling at the process-level. In this paper, a diagnosis of the nature and impacts of local land-atmosphere coupling (LoCo) during dry and wet extreme conditions is presented using a combination of models and observations during the summers of 2006 and 2007 in the U.S. Southern Great Plains. A range of diagnostics exploring the links and feedbacks between soil moisture and precipitation are applied to the dry/wet regimes exhibited in this region, and in the process a thorough evaluation of nine different land-PBL scheme couplings is conducted under the umbrella of a high-resolution regional modeling testbed. Results show that the sign and magnitude of errors in land surface energy balance components are sensitive to the choice of land surface model, regime type, and running mode. In addition, LoCo diagnostics show that the sensitivity of L-A coupling is stronger towards the land during dry conditions, while the PBL scheme coupling becomes more important during the wet regime. Results also demonstrate how LoCo diagnostics can be applied to any modeling system (e.g. reanalysis products) in the context of their integrated impacts on the process-chain connecting the land surface to the PBL and in support of hydrological anomalies.

  2. Predicting spatial patterns of eagle migration using a mesoscale atmospheric model: a case study associated with a mountain-ridge wind development

    NASA Astrophysics Data System (ADS)

    Ainslie, B.; Alexander, N.; Johnston, N.; Bradley, J.; Pomeroy, A. C.; Jackson, P. L.; Otter, K. A.

    2014-01-01

    High resolution numerical atmospheric modeling around a mountain ridge in Northeastern British Columbia (BC), Canada was performed in order to examine the influence of meteorology and topography on Golden Eagle migration pathways at the meso-scale (tens of km). During three eagle fall migration periods (2007-2009), local meteorological conditions on the day of peak bird counts were modeled using the Regional Atmospheric Modeling System (RAMS) mesoscale model. Hourly local surface wind speed, wind direction, temperature, pressure and relative humidity were also monitored during these migration periods. Eagle migration flight paths were observed from the ground and converted to three-dimensional tracks using ArcGIS. The observed eagle migration flight paths were compared with the modeled vertical velocity wind fields. Flight tracks across the study area were also simulated using the modeled vertical velocity field in a migration model based on a fluid-flow analogy. It was found that both the large-scale weather conditions and the horizontal wind fields across the study area were broadly similar on each of the modeled migration days. Nonetheless, the location and density of flight tracks across the domain varied between days, with the 2007 event producing more tracks to the southwest of the observation location than the other 2 days. The modeled wind fields suggest that it is not possible for the eagles to traverse the study area without leaving updraft regions, but birds do converge on the locations of updrafts as they move through the area. Statistical associations between observed eagles positions and the vertical velocity field suggest that to the northwest (and to a lesser extent the southwest) of the main study ridge (Johnson col), eagles can always find updrafts but that they must pass through downdraft regions in the NE and SE as they make their way across the study area. Finally, the simulated flight tracks based on the fluid-flow model and the vertical

  3. Advances in studies of the middle and upper atmosphere and their coupling with the lower atmosphere

    NASA Astrophysics Data System (ADS)

    Lü, Daren; Yi, Fan; Xu, Jiyao

    2004-06-01

    Recent advances in studies of the middle and upper atmosphere and their coupling with the lower atmosphere in China are briefly reviewed. This review emphasizes four aspects: (1) Development of instrumentation for middle and upper atmosphere observation; (2) Analyses and observation of middle and upper atmosphere; (3) Theoretical and modeling studies of planetary wave and gravity wave activities in the middle atmosphere and their relation to lower atmospheric processes; (4) Study on the coupling between the stratosphere and the troposphere.

  4. Experimental study of ocean-atmosphere exchanges

    SciTech Connect

    Eymard, L.; Weill, A.; Planton, S.

    1994-12-31

    The SOFIA/ASTEX and SEMAPHORE campaigns were performed over open ocean, near the Azores, to study the ocean-atmosphere exchanges at the local and meso-scales, with a particular insight to the spatial variability of fluxes and related processes. In both cases, the experimental strategy involved two research aircraft and an oceanographic vessel, as well as surface buoys. SOFIA/ASTEX was more particularly devoted to the study of boundary layer and cloud properties, including microphysical and radiative aspects, in the framework of the international campaign ASTEX. SEMAPHORE was aimed at the analysis of surface fluxes and interactions with the upper ocean at the mesoscale. It included an important network of ocean circulation and thermal properties, from ships, current meter moorings, current drifters, and drifting buoys. The thermal front associated with the Azores current is an important feature of the ocean circulation and was particularly investigated. The analysis of data from meteorological satellites is also an important aspect of the two campaigns.

  5. Impact of the Loess Plateau on the atmospheric boundary layer structure and air quality in the North China Plain: a case study.

    PubMed

    Hu, Xiao-Ming; Ma, ZhiQiang; Lin, Weili; Zhang, Hongliang; Hu, Jianlin; Wang, Ying; Xu, Xiaobin; Fuentes, Jose D; Xue, Ming

    2014-11-15

    The North China Plain (NCP), to the east of the Loess Plateau, experiences severe regional air pollution. During the daytime in the summer, the Loess Plateau acts as an elevated heat source. The impacts of such a thermal effect on meteorological phenomena (e.g., waves, precipitation) in this region have been discussed. However, its impacts on the atmospheric boundary layer structure and air quality have not been reported. It is hypothesized that the thermal effect of the Plateau likely modulates the boundary layer structure and ambient concentrations of pollutants over the NCP under certain meteorological conditions. Thus, this study investigates such effect and its impacts using measurements and three-dimensional model simulations. It is found that in the presence of daytime westerly wind in the lower troposphere (~1 km above the NCP), warmer air above the Loess Plateau was transported over the NCP and imposed a thermal inversion above the mixed boundary layer, which acted as a lid and suppressed the mixed layer growth. As a result, pollutants accumulated in the shallow mixed layer and ozone was efficiently produced. The downward branch of the thermally-induced Mountain-Plains Solenoid circulation over the NCP contributed to enhancing the capping inversion and exacerbating air pollution. Previous studies have reported that low mixed layer, a factor for elevated pollution in the NCP, may be caused by aerosol scattering and absorption of solar radiation, frontal inversion, and large scale subsidence. The present study revealed a different mechanism (i.e., westerly warm advection) for the suppression of the mixed layer in summer NCP, which caused severe O3 pollution. This study has important implications for understanding the essential meteorological factors for pollution episodes in this region and forecasting these severe events. PMID:25192929

  6. Contribution of CO2 and H2S emitted to the atmosphere by plume and diffuse degassing from volcanoes: the Etna volcano case study

    NASA Astrophysics Data System (ADS)

    Hernández, Pedro A.; Melián, Gladys; Giammanco, Salvatore; Sortino, Francesco; Barrancos, José; Pérez, Nemesio M.; Padrón, Eleazar; López, Manuela; Donovan, Amy; Mori, Toshiya; Notsu, Kenji

    2015-05-01

    Active subaerial volcanoes often discharge large amounts of CO2 and H2S to the atmosphere, not only during eruptions but also during periods of quiescence. These gases are discharged through focused (plumes, fumaroles, etc.) and diffuse emissions. Several studies have been carried out to estimate the global contribution of CO2 and H2S emitted to the atmosphere by subaerial volcanism, but additional volcanic degassing studies will help to improve the current estimates of both CO2 and H2S discharges. In October 2008, a wide-scale survey was carried out at Mt. Etna volcano, one the world's most actively degassing volcanoes on Earth, for the assessment of the total budget of volcanic/hydrothermal discharges of CO2 and H2S, both from plume and diffuse emissions. Surface CO2 and H2S effluxes were measured by means of the accumulation chamber method at 4075 sites, covering an area of about 972.5 km2. Concurrently, plume SO2 emission at Mt. Etna was remotely measured by a car-borne Differential Optical Absorption Spectrometry (DOAS) instrument. Crater emissions of H2O, CO2 and H2S were estimated by multiplying the plume SO2 emission times the H2O/SO2, CO2/SO2 and H2S/SO2 gas plume mass ratios measured in situ using a portable multisensor. The total output of diffuse CO2 emission from Mt. Etna was estimated to be 20,000 ± 400 t day-1 with 4520 t day-1 of deep-seated CO2. Diffuse H2S output was estimated to be 400 ± 20 kg day-1, covering an area of 9.1 km2 around the summit craters of the volcano. Diffuse H2S emission on the volcano flanks was either negligible or null, probably due to scrubbing of this gas before reaching the surface. During this study, the average crater SO2 emission rate was ~2100 t day-1. Based on measured SO2 emission rates, the estimated H2O, CO2 and H2S emission rates from Etna's crater degassing were 220,000 ± 100,000, 35,000 ± 16,000 and 510 ± 240 t day-1, respectively. These high values are explained in terms of intense volcanic activity at

  7. Atmospheric Modeling And Sensor Simulation (AMASS) study

    NASA Technical Reports Server (NTRS)

    Parker, K. G.

    1984-01-01

    The capabilities of the atmospheric modeling and sensor simulation (AMASS) system were studied in order to enhance them. This system is used in processing atmospheric measurements which are utilized in the evaluation of sensor performance, conducting design-concept simulation studies, and also in the modeling of the physical and dynamical nature of atmospheric processes. The study tasks proposed in order to both enhance the AMASS system utilization and to integrate the AMASS system with other existing equipment to facilitate the analysis of data for modeling and image processing are enumerated. The following array processors were evaluated for anticipated effectiveness and/or improvements in throughput by attachment of the device to the P-e: (1) Floating Point Systems AP-120B; (2) Floating Point Systems 5000; (3) CSP, Inc. MAP-400; (4) Analogic AP500; (5) Numerix MARS-432; and (6) Star Technologies, Inc. ST-100.

  8. Case Studies Behavior Modification.

    ERIC Educational Resources Information Center

    Wark, David M.

    The case histories of five students enrolled in a university course in how to study are reported. The students ranged in age from 18 to 35, included two males and three females, and varied in school experience from no college in one case and some college in two cases to college degrees in two cases. Students were initially taught to chart their…

  9. Hydrochemistry dynamics in remote mountain lakes and its relation to catchment and atmospheric features: the case study of Sabocos Tarn, Pyrenees.

    PubMed

    Santolaria, Zoe; Arruebo, Tomas; Urieta, José Santiago; Lanaja, Francisco Javier; Pardo, Alfonso; Matesanz, José; Rodriguez-Casals, Carlos

    2015-01-01

    Increasing the understanding of high mountain lake dynamics is essential to use these remote aquatic ecosystems as proxies of global environmental changes. With this aim, at Sabocos, a Pyrenean cirque glacial lake or tarn, this study shows the main results of a morphological and catchment characterization, along with statistical analyses of its hydrochemical trends and their concomitant driving factors from 2010 to 2013. Dissolved oxygen, water temperature stratification, and its snow and ice cover composition and dynamics have been also investigated. According to morphological analyses, Sabocos can be classified as a medium-large and deep lake, having a circular contour and a long water retention time as compared to Pyrenean glacial lake average values. Sabocos hydrochemistry is mainly determined by very high alkalinity, pH and conductivity levels, and high Ca(2+), Mg(2+), and SO4(2-) content, coming from the easily weatherable limestone-dolomite bedrock. Thus, lake water is well buffered, and therefore, Sabocos tarn is non-sensitive to acidification processes. On the other hand, the main source of K(+), Na(+), and Cl(-) (sea salts) and nutrients (NH4(+), NO3(-), and phosphorous) to lake water appears to be atmospheric deposition. Primary production is phosphorous limited, and due to the N-saturation stage of the poorly developed soils of Sabocos catchment, NO3(-) is the chief component in the total nitrogen pool. External temperature seems to be the major driver regulating lake productivity, since warm temperatures boot primary production. Although precipitation might also play an important role in lake dynamics, especially regarding to those parameters influenced by the weathering of the bedrock, its influence cannot be easily assessed due to the seasonal isolation produced by the ice cover. Also, as occurs in the whole Pyrenean lake district, chemical composition of bulk deposition is highly variable due to the contribution of air masses with different origin

  10. The Role of the Specialist Portal in the Global Data Bazaar- A Case Study of the International Arctic System for Observing the Atmosphere Data Portal Development

    NASA Astrophysics Data System (ADS)

    Starkweather, S.; Uttal, T.

    2013-12-01

    The virtual space for global data discovery has been compared to a bazaar [Parsons et al. 2011], where 'specialist portals provide the expertise, information, and referrals necessary to identify and understand data within a specific disciplinary context'. What then does an individual stall in this bazaar resemble? What are the technical and social actions by which this individual portal leverages the commons to increase activity in their area? The International Arctic Systems for Observing the Atmosphere (IASOA) was initiated to address key Arctic atmospheric science questions through coordinating the considerable atmospheric observing assets at ten pan-Arctic observatories. Since its formation, IASOA has discovered and linked to over 700 long-term datasets of relevance to its mission. IASOA science experts recognized that lack of uniform access to these datasets across contributing observatories was an impediment to progress in science synthesis. In the last year, structured, machine-readable metadata has been produced and harvested using an implementation of ISO-19115-2. The IASOA portal presents this collection within a dynamic measurement and place-based view that succinctly demonstrates data-rich and data-poor areas in Arctic atmospheric science. This presentation will demonstrate the achievements of IASOA's redesigned data portal. Technical highlights include a dynamic measurement-based organization of available data that leverages the semantics of leading global atmospheric science networks; a search results design which supports flexible and rapid access to original data and file format information; and information-rich linkages between platform-sensor metadata and dataset metadata. These achievements were not the result of cyber-infrastructure developments alone. This presentation will also review the social actions which underpin such a development, such as a cooperative schema development among data managers and an engaged community of experts focused on

  11. Generic aerocapture atmospheric entry study, volume 1

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An atmospheric entry study to fine a generic aerocapture vehicle capable of missions to Mars, Saturn, and Uranus is reported. A single external geometry was developed through atmospheric entry simulations. Aerocapture is a system design concept which uses an aerodynamically controlled atmospheric entry to provide the necessary velocity depletion to capture payloads into planetary orbit. Design concepts are presented which provide the control accuracy required while giving thermal protection for the mission payload. The system design concepts consist of the following elements: (1) an extendable biconic aerodynamic configuration with lift to drag ratio between 1.0 and 2.0; (2) roll control system concepts to control aerodynamic lift and disturbance torques; (3) aeroshell design concepts capable of meeting dynamic pressure loads during aerocapture; and (4) entry thermal protection system design concepts to meet thermodynamic loads during aerocapture.

  12. High-resolution spectrometer for atmospheric studies

    NASA Astrophysics Data System (ADS)

    Di Carlo, Piero; Barone, Massimiliano; D'Altorio, Alfonso; Dari-Salisburgo, Cesare; Pietropaolo, Ermanno

    2009-08-01

    A high-resolution spectrometer (0.0014 nm at 313 nm) has been developed at the University of L'Aquila (Italy) for atmospheric spectroscopic studies. The layout, optics and software for the instrument control are described. Measurements of the mercury low-pressure lamp lines from 200 to 600 nm show the high performances of the spectrometer. Laboratory measurements of OH and NO2 spectrums demonstrate that the system could be used for cross-section measurements and to detect these species in the atmosphere. The first atmospheric application of the system was the observation of direct solar and sky spectrums that shows a filling-in of the sky lines due to rotational Raman scattering. The measurements have been done with clear and cloudy sky and in both there was a strong dependence of the filling-in from the solar zenith angle whereas no dependence from the wavelengths was evident at low solar zenith angles (less than 85°).

  13. Stellar occultation studies of Saturn's upper atmosphere

    NASA Astrophysics Data System (ADS)

    Foust, Jeffrey Alan

    1999-10-01

    The properties of Saturn's upper atmosphere are not well- known despite several spacecraft flybys. However, the region of 1-100 μbar can be studied in detail by observing stellar occultations-when the planet passes in front of a star-from groundbased or Earth-orbiting telescopes. We use data from five such occultations: three observed in 1995 by the Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST), one observed in 1996 at the NASA Infrared Telescope Facility (IRTF) and one in 1989 observed by a different instrument at the IRTF. The data span latitudes from 52° south to 75° north. We fit isothermal models to each data set and also perform numerical inversions. These analyses show that temperatures in the 1-10 μbar range can vary significantly as a function of season and latitude, ranging from 121 to 160 K, in accordance with radiative transfer models for the atmosphere. We also search for evidence of gravity wave saturation in Saturn's upper atmosphere, as seen in other planetary atmospheres, by analyzing the power spectra of temperature and density data and by studying the temperature lapse rate in the atmosphere. Our analysis is consistent with saturated gravity waves for all data sets, although gravity wave saturation is not the sole explanation for the spectra. We take advantage of the wavelength-resolved HST FOS data to study the composition of Saturn's upper atmosphere. We measured the difference in feature times for data taken at two wavelengths, and use the different refractivities of hydrogen and helium, as a function of wavelength to compute the relative amounts of the two elements in the planet's atmosphere. We find that the helium mass fraction is 0.26 +/- 0.10, higher than that found using Voyager data, but marginally consistent with theoretical models for the evolution of Saturn's atmosphere, although the large error bars on the results make a definitive conclusion problematic. (Copies available exclusively from MIT Libraries, Rm

  14. Water vapor data assimilation for the atmospheric correction of D-InSAR products:Case study over Mts. Baekdu and Datun

    NASA Astrophysics Data System (ADS)

    Yun, Hye-Won; Kim, Jung-Rack; Lin, Shih-Yuan; Hong, Sung-Wook; Choi, Yun-Soo

    2013-04-01

    SAR campaign could be corrected. The test areas are two potential volcanoes, including Mt. Baekdu in Korea and Mt. Datun in Taiwan. Although the recent reports of crust activities have revealed that the Eastern Asian volcanoes are in dormant status, the two volcanoes have been the main focus of interests as they are very close to high population area. Therefore a monitoring for extracting correct deformation is critical. To the end the SAR data were proposed for the volcano monitoring task. However, in spite of several D-InSAR monitoring, the stratification water vapor and the erroneous base DTMs make it impossible to correctly observe true deformation. In this study, ENVISAT image sequences with error corrected D-InSAR technique were interpreted to detect the potential land deformation. As a result, small land deformations that might be interpreted as the influence caused at the stage of magmatic intrusion was identified in Mt. Baekdu. The whole D-InSAR processing was conducted over Mt. Datun again and the results were verified using the GPS data sets. Even if those are not genuine volcanic activities, continuous D-InSAR monitoring employing new SAR assets and the stable atmospheric correction are highly recommended to reduce the potential risks considering the reliable D-InSAR observation accuracy.

  15. The case study approach

    PubMed Central

    2011-01-01

    The case study approach allows in-depth, multi-faceted explorations of complex issues in their real-life settings. The value of the case study approach is well recognised in the fields of business, law and policy, but somewhat less so in health services research. Based on our experiences of conducting several health-related case studies, we reflect on the different types of case study design, the specific research questions this approach can help answer, the data sources that tend to be used, and the particular advantages and disadvantages of employing this methodological approach. The paper concludes with key pointers to aid those designing and appraising proposals for conducting case study research, and a checklist to help readers assess the quality of case study reports. PMID:21707982

  16. Studies of Land Atmosphere Coupling Using the Land Information System

    NASA Astrophysics Data System (ADS)

    Peters-Lidard, C. D.; Santanello, J. A.; Kumar, S. V.; Eastman, J. L.; Tao, W.

    2007-05-01

    Recent studies have examined aspects of land atmosphere coupling including the roles of soil moisture and vegetation, on the structure of the atmospheric boundary layer and initiation and evolution of clouds. However, due to limits in computational resources and/or theoretical knowledge, many of these studies have utilized highly parameterized representations of these components so that the true nature of land atmosphere coupling is still unknown. The NASA/GSFC Land Information System (LIS; http:lis.gsfc.nasa.gov) has now been successfully coupled to the Weather Research and Forecasting (WRF; http:www.wrfmodel.org) model, and now provides a testbed for conducting studies of land-atmosphere coupling at water and energy cycle process resolving horizontal spatial scales (1km or less). LIS is a high-performance Land Data Assimilation System (LDAS; http:ldas.gsfc.nasa.gov) that encapsulates the capabilities of the North American LDAS (NLDAS) and the Global LDAS (GLDAS) into a single software infrastructure. The original LIS consists of several land surface models (e.g., Noah, CLM, VIC, HySSiB, Catchment) that can be run in two modes: uncoupled or coupled. In uncoupled mode, the atmospheric boundary conditions are prescribed using observationally-based precipitation, radiation and meteorological inputs, while in coupled mode, these inputs are predicted by the WRF model. In both cases, LIS incorporates remotely sensed land surface parameters including Moderate Resolution Imaging Spectroradiometer (MODIS)-based Leaf Area Index (LAI). In this talk, we will present results from various coupled case studies indicating a strong sensitivity of the water and energy cycles to several controls, including soil moisture, vegetation, and the atmospheric boundary layer. We will also demonstrate the value of remotely sensed observations of ecosystem properties on predicting the timing and location of convection.

  17. Chemical Data Assimilation: A Case Study of Solar Occultation Data From the Atlas 1 Mission of the Atmospheric Trace Molecule Spectroscopy Experiment

    NASA Technical Reports Server (NTRS)

    Lary, D. J.; Khattatov, B.; Mussa, H.

    2003-01-01

    A key advantage of using data assimilation is the propagation of information from data-rich regions to data-poor regions, which is particularly relevant to the use of solar occultation data such as from ATMOS. For the first time an in depth uncertainty analyses is included in a photochemical model-data intercomparison including observation, representativeness, and theoretical uncertainty. Chemical data assimilation of solar occultation measurements can be used to reconstruct full diurnal cycles and to evaluate their chemical self-consistency. This paper considers as an example the measurements made by the Atmospheric Trace Molecule Spectroscopy Experiment (ATMOS) instrument Atlas-1 during March 1992 for a vertical profile flow tracking coordinates at an equivalent PV latitude of 38 S. ATMOS was chosen because it simultaneously observes several species. This equivalent PV latitude was chosen as it was where ATMOS n observed the atmosphere's composition over the largest range of altitudes. A single vertical profile was used so that the detailed diurnal information that assimilation utilizes could be highlighted. There is generally good self-consistency between the ATMOS Atlas-1 observations and photochemical theory.

  18. Does evolution matter?: a case study in Brazil of the effects of an evolutionary-thinking academic atmosphere in postgraduate students' belief in God/religious belief.

    PubMed

    Dias, Ivan A; Willemart, Rodrigo H; Marques, Antonio C

    2012-06-01

    Although the theory of evolution is more than 150 years old, a substantial proportion of the world population does not mention it when explaining the origin of human beings. The usual alternative conception is offered by creationism, one of the main obstacles to full acceptance of evolution in many countries. National polls have demonstrated that schooling and religiosity are negatively correlated, with scientists being one of the least religious professionals. Herein we analyzed both (1) the profile of 1st semester undergraduate students and (2), thesis and dissertations, concerning religious and evolutionary thoughts from Biology and Veterinary Schools at the largest university of South America. We have shown that students of Biology are biased towards evolution before they enter university and also that the presence of an evolutionary-thinking academic atmosphere influences the deism/religiosity beliefs of postgraduate students. PMID:22522675

  19. [Qualitative case study].

    PubMed

    Debout, Christophe

    2016-06-01

    The qualitative case study is a research method which enables a complex phenomenon to be explored through the identification of different factors interacting with each other. The case observed is a real situation. In the field of nursing science, it may be a clinical decision-making process. The study thereby enables the patient or health professional experience to be conceptualised. PMID:27338694

  20. SETDA Case Studies 2012

    ERIC Educational Resources Information Center

    State Educational Technology Directors Association, 2012

    2012-01-01

    The State Educational Technology Directors Association (SETDA) published a series of case studies from 28 states to showcase examples of how ARRA EETT ("American Recovery and Reinvestment Act of 2009 Enhancing Education Through Technology") grant funds have impacted teaching and learning. SETDA collected data for the case studies through a variety…

  1. [Research on impact of dust event frequency on atmosphere visibility variance: a case study of typical weather stations locating in the dust route to Beijing].

    PubMed

    Qiu, Yu-jun; Zou, Xue-yong; Zhang, Chun-lai

    2006-06-01

    Relationship between dust event frequency and atmosphere visibility deviation is analyzed by using the data of daily visibility and various dust events in Beijing and other 13 typical weather stations locating in the dust events route to Beijing from 1971 to 2000. Results show that the visibility variance increases a standard deviation in the response to the dust event frequency decrease once. The influence of dust event to visibility comes from the high-frequency change of wind velocity. The change of wind velocity in one standard deviation can result in dust event frequency increasing by 30%. The high-frequency changes of near-surface wind influence the occurrence of dust event, and also the fluctuation of daily visibility deviation. The relationship between abnormal low visibility event and visibility deviation is in significant positive correlation. The increase of wind average distance leads to the enhance frequency of dust event and consequently the abnormal low visibility event. There are different relationships between abnormal low visibility event and floating dust, sandstorm and flying-dust respectively. PMID:16921932

  2. Multiwavelength Studies For Titan's Atmospheric Composition Analysis

    NASA Astrophysics Data System (ADS)

    Benilan, Yves; Sebbar, E. Es; Fray, N.; Gazeau, M.; Jolly, A.; Schwell, M.; Guillemin, J.

    2009-09-01

    Titan's atmosphere mainly made of nitrogen and methane is rich in organic molecules. Hydrocarbons are formed from the photolytic dissociation of CH4 and nitriles are created by dissociation of N2 followed by reactions with hydrocarbons. In order to understand the physicochemical mechanisms responsible for the evolution of Titan's atmosphere, photochemical models are built. The latter need constrains for vertical profiles of organic compounds from the high thermosphere down to the low stratosphere as well as photodissociation rates. Those profiles over the entire atmosphere can be retrieved from Cassini observations, in particular by limb sounding, coupling infrared and ultraviolet spectroscopy. However, in order to interpret those data obtained by the ultraviolet (UVIS) and infrared (CIRS) spectrometers on board Cassini's spacecraft, precise spectroscopic parameters and their dependence on temperature are needed. We will review the current knowledge in this field of planetary spectroscopy and point out the lack of spectroscopic parameters of already detected species, especially for radiative transfer calculations at low temperature. We will focus our talk on the Cyanogen molecule (C2N2) which has been observed in Titan atmosphere in the FIR domain around 230 cm-1. We will present the latest spectroscopic studies we have performed on this molecule. Those studies cover the entire spectrum from the mid- infrared and to the vacuum ultraviolet. Integrated band intensities have been determined for all bands in the infrared. In the ultraviolet domain, we have determined absolute cross sections from 350 down to 80 nm covering six orders of magnitude absorptions. We will also show how temperature can influence VUV absorption coefficients and the implications on the interpretation of UVIS observations.

  3. Modelling the transfer of 14C from the atmosphere to grass: a case study in a grass field near AREVA-NC La Hague.

    PubMed

    Aulagnier, C; Le Dizès, S; Maro, D; Hébert, D; Lardy, R; Martin, R; Gonze, M-A

    2012-10-01

    Radioactive (14)C is formed as a by-product of nuclear power generation and from operation of nuclear fuel reprocessing plants like AREVA-NC La Hague (North France), which releases about 15 TBq per year of (14)C into the atmosphere. Since the autumn of 2006, (14)C activity concentrations in samples from the terrestrial environment (air, grass and soil) have been monitored monthly on grassland 2 km downwind of the reprocessing plant. The monitoring data provides an opportunity to validate radioecology models used to assess (14)C transfer to grassland ecosystems. This article compares and discusses the ability of two different models to reproduce the observed temporal variability in grass (14)C activity in the vicinity of AREVA-NC La Hague. These two models are the TOCATTA model which is specifically designed for modelling transfer of (14)C and tritium in the terrestrial environment, and PaSim, a pasture model for simulating grassland carbon and nitrogen cycling. Both TOCATTA and PaSim tend to under-estimate the magnitude of observed peaks in grass (14)C activity, although they reproduce the general trends. PaSim simulates (14)C activities in substrate and structural pools of the plant. We define a mean turn-over time for (14)C within the plant, which is based on both experimental data and the frequency of cuts. An adapted PaSim result is presented using the 15 and 20 day moving average results for the (14)C activity in the substrate pool, which shows a good match to the observations. This model reduces the Root Mean Square Error (RMSE) by nearly 40% in comparison to TOCATTA. PMID:22537618

  4. Study of atmospheric pollution scavenging. [Annotated bibligraphy

    SciTech Connect

    Williams, A.L.

    1990-08-01

    Atmospheric scavenging research conducted by the Illinois State Water Survey under contract with the Department of Energy has been a significant factor in the historical development of the field of precipitation scavenging. Emphasis of the work during the 1980's became focused on the problem of acid rain problem with the Survey being chosen as the Central Analytical Laboratory for sample analysis of the National Atmospheric Deposition Program National Trends Network (NADP/NTN). The DOE research was responsible for laying the groundwork from the standpoint of sampling and chemical analysis that has now become routine features of NADP/NTN. A significant aspect of the research has been the participation by the Water Survey in the MAP3S precipitation sampling network which is totally supported by DOE, is the longest continuous precipitation sampling network in existence, and maintains an event sampling protocol. The following review consists of a short description of each of the papers appearing in the Study of Atmospheric Scavenging progress reports starting with the Eighteenth Progress Report in 1980 to the Twenty- Third Progress Report in 1989. In addition a listing of the significant publications and interviews associated with the program are given in the bibliography.

  5. Atmospheric aerosol and Doppler lidar studies

    NASA Technical Reports Server (NTRS)

    Rothermel, Jeff; Bowdle, D. A.; Srivastava, V.; Jarzembski, M.; Cutten, D.; Mccaul, E. W., Jr.

    1991-01-01

    Experimental and theoretical studies were performed of atmospheric aerosol backscatter and atmospheric dynamics with Doppler lidar as a primary tool. Activities include field and laboratory measurement and analysis efforts. The primary focus of activities related to understanding aerosol backscatter is the GLObal Backscatter Experiment (GLOBE) program. GLOBE is a multi-element effort designed toward developing a global aerosol model to describe tropospheric clean background backscatter conditions that Laser Atmospheric Wind Sounder (LAWS) is likely to encounter. Two survey missions were designed and flown in the NASA DC-8 in November 1989 and May to June 1990 over the remote Pacific Ocean, a region where backscatter values are low and where LAWS wind measurements could make a major contribution. The instrument complement consisted of pulsed and continuous-wave (CW) CO2 gas and solid state lidars measuring aerosol backscatter, optical particle counters measuring aerosol concentration, size distribution, and chemical composition, a filter/impactor system collecting aerosol samples for subsequent analysis, and integrating nephelometers measuring visible scattering coefficients. The GLOBE instrument package and survey missions were carefully planned to achieve complementary measurements under clean background backscatter conditions.

  6. MULTIPLE CONTAMINANTS CASE STUDIES

    EPA Science Inventory

    The presentation provides information taken from the arsenic demonstration program projects that have treatment systems removing multiply contaminants from drinking water. The case studies sited in the presentation consist of projects that have arsenic along with either nitrate, ...

  7. Laos case study

    PubMed Central

    2012-01-01

    Peuan Mit is a Lao organization working to address the needs of children and youth living and working on the streets. This case study outlines how a trusted and strong relationship with local police provides mutual benefit. PMID:22769869

  8. HYDROGEOLOGIC CASE STUDIES

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  9. Electrodynamic studies of upper and lower atmospheric coupling

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Cornwall, J. M.; Edgar, B. C.; Schulz, M.; Sharp, L. R.

    1981-01-01

    Theoretical interprotations and data interpretations of electrodynamical studies in upper and lower atmosphere coupling are reported. The following topics are discussed: (1) magnetosphere/ionosphere/atmosphere coupling in auroral electrodynamics; (2) middle atmosphere electrodynamics; (3) thermosphere troposphere coupling; and (4) tropospheric electrodynamics. Understanding of the near Earth space environment shows the interrelationships between various components of the Earth's atmosphere.

  10. Tunable Infrared Laser Instruments for Airborne Atmospheric Studies

    NASA Technical Reports Server (NTRS)

    Fried, A.; Diskin, G.; Weibring, P.; Richter, D.; Walega, J. G.; Sachse, G.; Slate, T.; Rana, M.; Podolske, J.

    2008-01-01

    Tunable infrared laser-based instruments on airborne platforms have provided invaluable contributions to atmospheric studies over the past several decades. This paper presents an overview of some recent studies and developments using this approach that were presented at the 2007 Field Laser Applications in Industry and Research (FLAIR, http://www.inoa.it/flair/) conference in Florence, Italy. The present overview only covers select in situ absorption-based instruments that were presented in the airborne session at this conference. In no case are comprehensive details presented. These details can be found in the numerous references given. Additional approaches based upon cavity-enhanced and photoacoustic measurements, which are also making invaluable contributions in airborne atmospheric studies, are not discussed in this brief overview.

  11. KINETIC STUDIES OF SIMULATED POLLUTED ATMOSPHERES

    EPA Science Inventory

    The kinetics and reaction mechanisms of several important atmospheric contaminants - SO2, formaldehyde, nitrous acid, and the nitrosamines - were assessed to help quantify some key aspects of the chemistry of polluted atmospheres. The reactions and lifetimes of excited sulfur dio...

  12. Improving temporal profiles of anthropogenic emissions influenced by human activities and meteorological drivers for atmospheric dispersion modelling - a case study for the UK

    NASA Astrophysics Data System (ADS)

    Vieno, M.; Reis, S.; Ambelas Skjøth, C.; Lang, M.; Geels, C.

    2010-12-01

    Emissions of trace gases originating from anthropogenic activities are vital input data for chemical transport models (CTMs). Other key input datasets such as meteorological drivers, and biogeochemical and physical processes have been subject to detailed investigation and research in the recent past, while the representation of emission data in CTMs has been somewhat neglected. Arguably, this has less impact on the regional to hemispheric or global scale, where the grid sizes of currently applied CTMs represent well mixed average concentrations or deposition values. Evaluating model output against ground-based observations or remote sensing results on these spatial levels appears not to be overly sensitive to the temporal (and spatial) profiles of emission input data. With increasing level of detail and spatiotemporal resolution, CTMs applied to determine national or local scale air quality are likely prone to be more sensitive to the spatial and temporal patterns of anthropogenic emissions. This paper discusses results of the application of the EMEP4UK CTM on a 5 km x 5 km resolution for the whole of the United Kingdom. In a first instance, detailed temporal profiles for emissions from road transport, power generation and other stationary sources have been developed. Depending on typical sectoral activities, hourly to seasonal variations have been quantified and (sub-)sectoral time curves generated. Here, we will discuss how these improved time curves influence modelled concentrations of NO2, Ozone and PM10 for selected episodes in the year 2007. In a second application, both anthropogenic activities (e.g. manure spreading and fertilizer application) and meteorological factors (e.g. temperature and seasonality) have been investigated regarding their influence on the spatiotemporal distribution of NH3 emissions (Skjøth et al., 2004; see as well Pinder et al., 2004; Gilliland et al., 2006). The discussion of results in this case will focus on the impact on the

  13. Mass concentration coupled with mass loading rate for evaluating PM(2.5) pollution status in the atmosphere: A case study based on dairy barns.

    PubMed

    Joo, HungSoo; Park, Kihong; Lee, Kwangyul; Ndegwa, Pius M

    2015-12-01

    This study investigated particulate matter (PM) loading rates and concentrations in ambient air from naturally ventilated dairy barns and also the influences of pertinent meteorological factors, traffic, and animal activities on mass loading rates and mass concentrations. Generally, relationships between PM2.5 concentration and these parameters were significantly poorer than those between the PM loading rate and the same parameters. Although ambient air PM2.5 loading rates correlated well with PM2.5 emission rates, ambient air PM2.5 concentrations correlated poorly with PM2.5 concentrations in the barns. A comprehensive assessment of PM2.5 pollution in ambient air, therefore, requires both mass concentrations and mass loading rates. Emissions of PM2.5 correlated strongly and positively with wind speed, temperature, and solar radiation (R(2) = 0.84 to 0.99) and strongly but negatively with relative humidity (R(2) = 0.93). Animal activity exhibited only moderate effect on PM2.5 emissions, while traffic activity did not significantly affect PM2.5 emissions. PMID:26452004

  14. Infrared laboratory studies of synthetic planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1972-01-01

    The initial stages of the research were involved with a test of Burch's law of multiplicative transmittance for mixed absorbing gases when their lines are broadened by H2 and He, which are constituents of the atmospheres of the major planets. The broadening of individual lines in the CO fundamental by various gases was investigated. Line strength and half-width for individual CO lines were studied as a function of temperature. Measurements of total band absorptance as a function of absorber thickness and total effective pressure were made at various temperatures for bands of CO and N2O. Attempts were made to develop a phenomenological theory of line broadening that would account for the phenomena observed for the CO fundamental and those reported for more highly polar gases. Laboratory measurements of nitric acid vapor absorptance were compared with balloon measurements in arriving at an estimate of the quantity of nitric acid vapor present in the earth's atmosphere in the region of the ozone layer.

  15. Atmospheric cloud physics laboratory project study

    NASA Technical Reports Server (NTRS)

    Schultz, W. E.; Stephen, L. A.; Usher, L. H.

    1976-01-01

    Engineering studies were performed for the Zero-G Cloud Physics Experiment liquid cooling and air pressure control systems. A total of four concepts for the liquid cooling system was evaluated, two of which were found to closely approach the systems requirements. Thermal insulation requirements, system hardware, and control sensor locations were established. The reservoir sizes and initial temperatures were defined as well as system power requirements. In the study of the pressure control system, fluid analyses by the Atmospheric Cloud Physics Laboratory were performed to determine flow characteristics of various orifice sizes, vacuum pump adequacy, and control systems performance. System parameters predicted in these analyses as a function of time include the following for various orifice sizes: (1) chamber and vacuum pump mass flow rates, (2) the number of valve openings or closures, (3) the maximum cloud chamber pressure deviation from the allowable, and (4) cloud chamber and accumulator pressure.

  16. Multiphase studies in continental and marine atmospheres

    NASA Astrophysics Data System (ADS)

    Acker, K.; Wieprecht, W.; Möller, D.

    2010-07-01

    The largest uncertainty in future climate predictions is caused by aerosols and clouds and their interaction with radiation (IPCC, 2007). Aerosol particles have multiple impacts on atmospheric properties: response to climate by optical properties, providing cloud condensation nuclei, being a heterogeneous surface for multiphase chemical reactions e.g. as a source for reactive chlorine. Therefore the chlorine partitioning in marine and continental atmospheres was studied during intensive field campaigns at two European Supersites for Atmospheric Aerosol Research: Melpitz (51°32N, 12°54 E; 87 m a.s.l., near Leipzig (D), Spindler et al., 2004) and Mace Head (53°19 N, 9°54 W; ~10 m a.s.l., near Galway (IR); O`Connor et al., 2008). Hydrochloric acid (HCl), nitric acid (HNO3) and other gaseous species as well after diffusion based separation particulate matter components (e.g., Na, Cl, nitrate, sulphate and others) were determined simultaneously by a denuder-steam chamber-IC-system with a time resolution of 30 min; limit of quantification: 10 ng m-3 (air flow 10 l min-1; Acker et al., 2005). Numerous other atmospheric components (in gas and particulate phase) as well meteorological parameters were determined. Assuming Na to be only of sea-salt origin, the (mass) Na/Cl ratio found in sea water (Rsea = 0.56) is used for calculation of the degree in chlorine loss in particulate matter: Clloss=1-Rsea/Rsample. In Mace Head to a significant extent (~ 20%), sea salt already is depleted in Cl in air masses originate exclusive from the clean marine sector, mainly caused by HCl formation during heterogeneous sulphate formation. In continental influenced air masses a higher degree in Clloss (~ 46%) was found due to additional acid replacement by nitric acid. In air masses arriving Melpitz a very high loss in chlorine has been observed in the aerosol (~ 83%), not showing a significant dependency from the air mass sector and transport percentage above continent. The high

  17. Polar nephelometer for atmospheric particulate studies

    NASA Technical Reports Server (NTRS)

    Hansen, M. Z.; Evans, W. H.

    1980-01-01

    A polar nephelometer for use in studying atmospheric aerosols was developed. The nephelometer detects molecular scatter from air and measures scattering from very clean air using pure molecular scattering for calibration. A compact system using a folded light path with an air cooled argon laser for the light source was designed. A small, sensitive detector unit permits easy angular rotation for changing the scattering angle. A narrow detector field of view of + or - 1/4 degree of scattering along with a single wavelength of incident light is used to minimize uncertainties in the scattering theory. The system is automated for data acquisition of the scattering matrix elements over an angular range from 2 degrees to 178 degrees of scattering. Both laser output and detector sensitivity are monitored to normalize the measured light scattering.

  18. Laboratory Studies of Atmospheric Heterogeneous Chemistry

    NASA Technical Reports Server (NTRS)

    Keyser, L. F.; Leu, M-T.

    1993-01-01

    In the laboratory, ice films formed by freezing from the liquid or more frequently by deposition from the vapor phase have been used to simulate stratospheric cloud surfaces for measurements of reaction and uptake rates. To obtain intrinsic surface reaction probabilities that can be used in atmospheric models, the area of the film surface that actually takes part in the reaction must be known. It is important to know not only the total surface area but also the film morphology in order to determine where and how the surface is situated and, thus, what fraction of it is available for reaction. Information on the structure of these ice films has been obtained by using several experimental methods. In the sections that follow, these methods will be discussed, then the results will be used to construct a working model of the ice films, and finally the model will be applied to an experimental study of HC1 uptake by H_2O ice.

  19. Geothermal Case Studies

    DOE Data Explorer

    Young, Katherine

    2014-09-30

    database.) In fiscal year 2015, NREL is working with universities to populate additional case studies on OpenEI. The goal is to provide a large enough dataset to start conducting analyses of exploration programs to identify correlations between successful exploration plans for areas with similar geologic occurrence models.

  20. Case Studies in Biology.

    ERIC Educational Resources Information Center

    Zeakes, Samuel J.

    1989-01-01

    A case study writing exercise used in a course on parasitology was found to be a powerful learning experience for students because it involved discipline-based technical writing and terminology, brought the students in as evaluators, applied current learning, caused interaction among all students, and simulated real professional activities. (MSE)

  1. Atrial fibrillation case study.

    PubMed

    Johnson, Sarah; Wilson, Tracey

    2016-03-01

    This article discusses the irregular heart rhythm caused by atrial fibrillation (AF). A brief overview of the pathophysiology will be provided. A case study is discussed to highlight the treatment and management of AF. The care provision describes common signs and symptoms and also the treatment and management of AF within the maternity care setting. The importance of maintaining the mother-baby dyad is highlighted. For the purpose of maintaining confidentiality the woman will be referred to as Shama. PMID:27044188

  2. Atmospheric Modeling And Sensor Simulation (AMASS) study

    NASA Technical Reports Server (NTRS)

    Parker, K. G.

    1985-01-01

    A 4800 band synchronous communications link was established between the Perkin-Elmer (P-E) 3250 Atmospheric Modeling and Sensor Simulation (AMASS) system and the Cyber 205 located at the Goddard Space Flight Center. An extension study of off-the-shelf array processors offering standard interface to the Perkin-Elmer was conducted to determine which would meet computational requirements of the division. A Floating Point Systems AP-120B was borrowed from another Marshall Space Flight Center laboratory for evaluation. It was determined that available array processors did not offer significantly more capabilities than the borrowed unit, although at least three other vendors indicated that standard Perkin-Elmer interfaces would be marketed in the future. Therefore, the recommendation was made to continue to utilize the 120B ad to keep monitoring the AP market. Hardware necessary to support requirements of the ASD as well as to enhance system performance was specified and procured. Filters were implemented on the Harris/McIDAS system including two-dimensional lowpass, gradient, Laplacian, and bicubic interpolation routines.

  3. Low latitude middle atmosphere ionization studies

    NASA Technical Reports Server (NTRS)

    Bassi, J. P.

    1976-01-01

    Low latitude middle atmosphere ionization was studied with data obtained from three blunt conductivity probes and one Gerdien condenser. An investigation was conducted into the effects of various ionization sources in the 40 to 65 Km altitude range. An observed enhancement of positive ion conductivity taking place during the night can be explained by an atmsopheric effect, with cosmic rays being the only source of ionization only if the ion-ion recombination coefficient (alpha sub i) is small(10 to the -7 power cu cm/s) and varies greatly with altitude. More generally accepted values of alpha sub i ( approximately equal to 3x10 to the -7 power cu cm/s) require an additional source of ionization peaking at about 65 Km, and corresponding approximately to the integrated effect of an X-ray flux measured on a rocket flown in conjunction with the ionization measurements. The reasonable assumption of an alpha sub i which does not vary with altitude in the 50-70 Km range implies an even greater value alpha sub i and a more intense and harder X-ray spectrum.

  4. Highlights in the study of exoplanet atmospheres.

    PubMed

    Burrows, Adam S

    2014-09-18

    Exoplanets are now being discovered in profusion. To understand their character, however, we require spectral models and data. These elements of remote sensing can yield temperatures, compositions and even weather patterns, but only if significant improvements in both the parameter retrieval process and measurements are made. Despite heroic efforts to garner constraining data on exoplanet atmospheres and dynamics, reliable interpretation has frequently lagged behind ambition. I summarize the most productive, and at times novel, methods used to probe exoplanet atmospheres; highlight some of the most interesting results obtained; and suggest various broad theoretical topics in which further work could pay significant dividends. PMID:25230656

  5. Study of atmospheric diffusion using LANDSAT

    NASA Technical Reports Server (NTRS)

    Torsani, J. A.; Viswanadham, Y.

    1982-01-01

    The parameters of diffusion patterns of atmospheric pollutants under different conditions were investigated for use in the Gaussian model for calculation of pollution concentration. Value for the divergence pattern of concentration distribution along the Y axis were determined using LANDSAT images. Multispectral scanner images of a point source plume having known characteristics, wind and temperature data, and cloud cover and solar elevation data provided by LANDSAT, were analyzed using the 1-100 system for image analysis. These measured values are compared with pollution transport as predicted by the Pasquill-Gifford, Juelich, and Hoegstroem atmospheric models.

  6. Highlights in the study of exoplanet atmospheres

    NASA Astrophysics Data System (ADS)

    Burrows, Adam S.

    2014-09-01

    Exoplanets are now being discovered in profusion. To understand their character, however, we require spectral models and data. These elements of remote sensing can yield temperatures, compositions and even weather patterns, but only if significant improvements in both the parameter retrieval process and measurements are made. Despite heroic efforts to garner constraining data on exoplanet atmospheres and dynamics, reliable interpretation has frequently lagged behind ambition. I summarize the most productive, and at times novel, methods used to probe exoplanet atmospheres; highlight some of the most interesting results obtained; and suggest various broad theoretical topics in which further work could pay significant dividends.

  7. Conducting and Reporting Case Studies.

    ERIC Educational Resources Information Center

    Lichtman, Merilyn; Taylor, Satomi Izumi

    Issues and elements of case study research are explored and illustrated with the example of a case study of a kindergarten in a suburb of Tokyo (Japan). Case study research is a type of qualitative research that concentrates on a single unit or entity, with boundaries established by the researcher. The case is an example drawn from a larger class,…

  8. Infrared laboratory studies of synthetic planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Williams, D.

    1973-01-01

    Previous research dealing with telluric gases is briefly reviewed. Current research concerning absorption-line broadening, and particulate constituents of planetary atmospheres are discussed. Two articles are included: optical constants of liquid ammonia in the infrared, and broadening of infrared absorption lines at reduced temperatures for nitrous oxide.

  9. Airborne Raman Lidar and its Applications for Atmospheric Process Studies

    NASA Astrophysics Data System (ADS)

    Wang, Zhien; Wechsler, Perry J.; Mahon, Nick; Wu, Decheng; Liu, Bo; Burkhart, Matthew; Glover, Brent; Kuestner, William; Welch, Wayne; Thomson, Andrew

    2016-06-01

    Although ground-base Raman lidars are widely used for atmospheric observations, the capabilities of airborne Raman lidar is not fully explored. Here we presented two recently developed airborne Raman lidar systems for the studies of atmospheric boundary layer process, aerosols, and clouds. The systems are briefly introduced. Observation examples are presented to illustrate the unique observational capabilities of airborne Raman lidar and their applications for atmospheric process studies.

  10. Idealized global nonhydrostatic atmospheric test cases on a reduced-radius sphere

    NASA Astrophysics Data System (ADS)

    Klemp, J. B.; Skamarock, W. C.; Park, S.-H.

    2015-09-01

    Idealized simulations on a reduced-radius sphere can provide a useful vehicle for evaluating the behavior of nonhydrostatic processes in nonhydrostatic global atmospheric dynamical cores provided the simulated cases exhibit good agreement with corresponding flows in a Cartesian geometry, and for which there are known solutions. Idealized test cases on a reduced-radius sphere are presented here that focus on both dry and moist dynamics. The dry dynamics cases are variations of mountain-wave simulations designed for the Dynamical Core Model Intercomparison Project (DCMIP), and permit quantitative comparisons with linear analytic mountain-wave solutions in a Cartesian geometry. To evaluate moist dynamics, an idealized supercell thunderstorm is simulated that has strong correspondence to results obtained on a flat plane, and which can be numerically converged by specifying a constant physical diffusion. A simple Kessler-type routine for cloud microphysics is provided that can be readily implemented in atmospheric simulation models. Results for these test cases are evaluated for simulations with the Model for Prediction across scales (MPAS). They confirm close agreement with corresponding simulations in a Cartestian geometry; the mountain-wave results agree well with analytic mountain-wave solutions, and the simulated supercells are consistent with other idealized supercell simulation studies and exhibit convergent behavior.

  11. Vertebral Angiosarcoma. Case Study.

    PubMed

    Guzik, Grzegorz

    2015-01-01

    Bone angiosarcomas, especially vertebral angiosarcomas, are very rare. There are no studies based on large clinical samples in the literature, and only a few single case reports can be found. The symptoms of the disease are not specific. It is usually detected incidentally or at a late stage when pathological vertebral fractures or neurological complications occur. Diagnostic imaging and history help to recognize the tumour behind the symptoms, but do not allow accurate clinical diagnosis. The basis for a diagnosis is the histopathological examination supported by immunohistochemistry (IHC) assays. The case of a 26-year-old woman with an angiosarcoma involving the eighth thoracic vertebra we report reflects diagnostic problems adversely affecting the efficacy and accuracy of treatment offered to patients. The patient underwent three surgeries of the spine, including two biopsies. A needle biopsy did not provide sufficient information for the diagnosis. An open excisional biopsy, which at the same time temporarily reduced neurological deficits in the patient, was the only chance to obtain an accurate diagnosis. The third surgery was posterior decompression of the spinal cord due to the rapidly escalating paraparesis. It was not until 8 weeks later that the final diagnosis was established. At that time, the patient could not be qualified for any supplementary treatment. The patient died in hospital 6 months after the onset of disease. PMID:26468177

  12. Polar nephelometer for atmospheric particulate studies.

    PubMed

    Hansen, M Z; Evans, W H

    1980-10-01

    A unique polar nephelometer was designed and constructed for the measurement of atmospheric particulate characteristics. The nephelometer produces visible light from a self-contained laser to irradiate an air sample drawn into the instrument. The light scattered from the particulates and molecules in the sample is detected as a function of scattering angle for each of four different incident light polarizations. These measurements are used to determine the particulate scattering matrix which is a function of the size, shape, and index of refraction of the particles. The region of sensitivity for the measurements corresponds to the size range of particles that strongly affects visible radiative transfer in the atmosphere, which is the primary application for the derived information. PMID:20234624

  13. Atmospheric corrections for satellite water quality studies

    NASA Technical Reports Server (NTRS)

    Piech, K. R.; Schott, J. R.

    1975-01-01

    Variations in the relative value of the blue and green reflectances of a lake can be correlated with important optical and biological parameters measured from surface vessels. Measurement of the relative reflectance values from color film imagery requires removal of atmospheric effects. Data processing is particularly crucial because: (1) lakes are the darkest objects in a scene; (2) minor reflectance changes can correspond to important physical changes; (3) lake systems extend over broad areas in which atmospheric conditions may fluctuate; (4) seasonal changes are of importance; and, (5) effects of weather are important, precluding flights under only ideal weather conditions. Data processing can be accomplished through microdensitometry of scene shadow areas. Measurements of reflectance ratios can be made to an accuracy of plus or minus 12%, sufficient to permit monitoring of important eutrophication indices.

  14. PREDICT : A CASE STUDY.

    SciTech Connect

    Kerscher, W. J. III; Booker, J. M.; Meyer, Mary A.

    2001-01-01

    Delphi Automotive Systems and the Los Alamos National Laboratory worked together to develop PREDICT, a new methodology to characterize the reliability of a new product during its development program. Rather than conducting testing after hardware has been built, and developing statistical confidence bands around the results, this updating approach starts with an early reliability estimate characterized by large uncertainty, and then proceeds to reduce the uncertainty by folding in fresh information in a Bayesian framework. A considerable amount of knowledge is available at the beginning of a program in the form of expert judgment which helps to provide the initial estimate. This estimate is then continually updated as substantial and varied information becomes available during the course of the development program. This paper presents a case study of the application of PREDICT, with the objective of further describing the methodology. PREDICT has been honored with an R&D 100 Award presented by R&D Magazine.

  15. Study of the Interaction of Micrometeoroids with Earth's Atmosphere

    NASA Astrophysics Data System (ADS)

    Briani, G.; Pupillo, G.; Aiello, S.; Pace, E.; Shore, S.; Passaro, A.

    Submillimetric micrometeoroids dominates the annual extraterrestrial mass flux toward the Earth. Indeed these bodies show an unexpected ability to survive the interaction with the terrestrial atmosphere. In this work it is suggested a new general numerical model for the micrometeoroids-atmosphere interaction: this is the first step of a more extended study \\citep{aiello} that includes also experiments for the next few years in laboratories as well in atmosphere (microsatellites or balloon-borne experiments).

  16. Role of runoff-infiltration partitioning and resolved overland flow on land-atmosphere feedbacks: A case-study with the WRF-Hydro coupled modeling system for West Africa

    NASA Astrophysics Data System (ADS)

    Arnault, Joel; Wagner, Seven; Rummler, Thomas; Fersch, Benjamin; Bliefernicht, Jan; Andresen, Sabine; Kunstmann, Harald

    2016-04-01

    The analysis of land-atmosphere feedbacks requires detailed representation of land processes in atmospheric models. Our focus here is on runoff-infiltration partitioning and resolved overland flow. In the standard version of WRF, runoff-infiltration partitioning is described as a purely vertical process. In WRF-Hydro, runoff is enhanced with lateral water flows. The study region is the Sissili catchment (12800 km2) in West Africa and the study period March 2003 - February 2004. Our WRF setup includes an outer and inner domain at 10 and 2 km resolution covering the West African and Sissili region, respectively. In our WRF-Hydro setup the inner domain is coupled with a sub-grid at 500 m resolution to compute overland and river flow. Model results are compared with TRMM precipitation, MTE evapotranspiration, CCI soil moisture, CRU temperature, and streamflow observation. The role of runoff infiltration partitioning and resolved overland flow on land-atmosphere feedbacks is addressed with a sensitivity analysis of WRF results to the runoff-infiltration partitioning parameter and a comparison between WRF and WRF-Hydro results, respectively. In the outer domain, precipitation is sensitive to runoff-infiltration partitioning at the scale of the Sissili area (~100x100 km2), but not of area A (500x2500 km2). In the inner domain, where precipitation patterns are mainly prescribed by lateral boundary conditions, sensitivity is small, but additionally resolved overland flow here clearly increases infiltration and evapotranspiration at the beginning of the wet season when soils are still dry. Our WRF-Hydro setup shows potential for joint atmospheric and terrestrial water balance studies, and reproduces observed daily discharge with a Nash-Sutcliffe model efficiency coefficient of 0.43.

  17. Russian studies of atmospheric ozone in 2011-2014

    NASA Astrophysics Data System (ADS)

    Elansky, N. F.

    2016-03-01

    This review contains the most important results obtained in Russian studies on atmospheric ozone in 2011-2014. It is part of the Russian National Report on Meteorology and Atmospheric Sciences that was prepared for the International Association of Meteorology and Atmospheric Sciences (IAMAS). This report was considered and approved at the XXVI General Assembly of the International Union of Geodesy and Geophysics (IUGG).1 The list of Russian publications on atmospheric ozone and its precursors for 2011-2014 is appended to this review.

  18. Natural Learning Case Study Archives

    ERIC Educational Resources Information Center

    Lawler, Robert W.

    2015-01-01

    Natural Learning Case Study Archives (NLCSA) is a research facility for those interested in using case study analysis to deepen their understanding of common sense knowledge and natural learning (how the mind interacts with everyday experiences to develop common sense knowledge). The database comprises three case study corpora based on experiences…

  19. Case Studies in Wilderness Medicine.

    ERIC Educational Resources Information Center

    Gray, Melissa; Tarter, Shana Lee

    Five case studies explore issues in wilderness medicine, with emphasis on evacuation decision making. The cases describe medical problems encountered during wilderness trips involving college or high school students. In each case, the situation and facts of the case are outlined, including the patient's medical history and vital signs, and at…

  20. Monte Carlo study of the atmospheric spread function

    NASA Technical Reports Server (NTRS)

    Pearce, W. A.

    1986-01-01

    Monte Carlo radiative transfer simulations are used to study the atmospheric spread function appropriate to satellite-based sensing of the earth's surface. The parameters which are explored include the nadir angle of view, the size distribution of the atmospheric aerosol, and the aerosol vertical profile.

  1. Studies of the observed and theoretical variations of atmospheric ozone

    NASA Technical Reports Server (NTRS)

    London, Julius

    1990-01-01

    The four related topics covered include: (1) distributions of total and upper atmospheric ozone and their time and space variations; (2) observed and theoretical models of the quasi-biennial oscillation (QBO) ozone variation; (3) radiative processes in the upper atmosphere; and (4) relations between ozone and solar variations. The results of these studies are presented. They come from twenty-three published papers.

  2. Termination: A Case Study.

    PubMed

    Friedberg, Ahron L

    2015-12-01

    In this article I posit and examine certain criteria and qualities for ending an analysis. The case study describes the end phase of a four-year psychoanalysis in which the patient's decision to move to another area forced the end of his analysis. We continued to explore and work through his core neurotic conflicts that included issues of competitive rivalry, dominance and submission, control, and anxiety about birth and death. A shift in the transference from me as a negative father to me as a supportive but competitive older brother was also examined in the context of ending treatment as well as other aspects of the transference. In addition, we analyzed the meaning of his ending treatment based on an extra-analytic circumstance. In discussing this phase of treatment, the definition and history of the term "termination" and its connotations are reviewed. Various criteria for completing an analysis are examined, and technical observations about this phase of treatment are investigated. It was found that while a significant shift in the transference occurred in this phase of the patient's analysis, conflicts related to the transference were not "resolved" in the classical sense. Terminating treatment was considered as a practical matter in which the patient's autonomy and sense of choice were respected and analyzed. PMID:26583444

  3. A Numerical Study of Micrometeoroids Entering Titan's Atmosphere

    NASA Technical Reports Server (NTRS)

    Templeton, M.; Kress, M. E.

    2011-01-01

    A study using numerical integration techniques has been performed to analyze the temperature profiles of micrometeors entering the atmosphere of Saturn s moon Titan. Due to Titan's low gravity and dense atmosphere, arriving meteoroids experience a significant cushioning effect compared to those entering the Earth's atmosphere. Temperature profiles are presented as a function of time and altitude for a number of different meteoroid sizes and entry velocities, at an entry angle of 45. Titan's micrometeoroids require several minutes to reach peak heating (ranging from 200 to 1200 K), which occurs at an altitude of about 600 km. Gentle heating may allow for gradual evaporation of volatile components over a wide range of altitudes. Computer simulations have been performed using the Cassini/Huygens atmospheric data for Titan. Keywords micrometeoroid Titan atmosphere 1 Introduction On Earth, incoming micrometeoroids (100 m diameter) are slowed by collisions with air molecules in a relatively compact atmosphere, resulting in extremely rapid deceleration and a short heating pulse, often accompanied by brilliant meteor displays. On Titan, lower gravity leads to an atmospheric scale height that is much larger than on Earth. Thus, deceleration of meteors is less rapid and these particles undergo more gradual heating. This study uses techniques similar to those used for Earth meteoroid studies [1], exchanging Earth s planetary characteristics (e.g., mass and atmospheric profile) for those of Titan. Cassini/Huygens atmospheric data for Titan were obtained from the NASA Planetary Atmospheres Data Node [4]. The objectives of this study were 1) to model atmospheric heating of meteoroids for a range of micrometeor entry velocities for Titan, 2) to determine peak heating temperatures and rates for micrometeoroids entering Titan s atmosphere, and 3) to create a general simulation environment that can be extended to incorporate additional parameters and variables, including different

  4. Calciphylaxis: a case study.

    PubMed

    Kauric-Klein, Zorica

    2012-01-01

    Caring for J.D. was a stressful experience. The extent of her wounds, pain, and limited options for treatment was very frustrating for the nursing staff. Although she did not survive, patient outcomes were met to some degree. Her pain was controlled to a greater extent, and there was less infection present in her wounds. The nurses worked with J.D. closely to improve her pain control and facilitate less painful dressing changes. They were vigilant in assessing the progress of her wound healing and communicating any increased signs of infections from her wounds. They sang with her to help distract her from the pain she was experiencing and to help her cope with her lengthy 8-month hospitalization. Providing care for J.D. was also a very important learning experience for nurses in terms of appropriate pain management for patients with CUA, wound care, and the need to sustain adequate nutrition to promote wound healing. CUA is a rare but potentially fatal disease that occurs in patients with end stage renal disease (ESRD). Early diagnosis and treatment are essential to prevent the devastating effects of this disease. Nephrology nurses need to reinforce the importance of keeping calcium, phosphorous, and parathyroid levels within normal ranges for their patients on dialysis. They also need to be vigilant in monitoring for potential CUA skin lesions to prevent and treat it early. To date, treatment options are mostly based on findings from case reports. Treatment requires a multidisciplinary approach with input from nephrologists, nurses, pain specialists, infectious disease specialists, and surgeons. The major goals of treatment are controlling risk factors, controlling pain, and preventing wound infection and possible sepsis. More studies need to be conducted to test interventions that may help treat CUA. PMID:23094342

  5. Teaching Pharmacology by Case Study.

    ERIC Educational Resources Information Center

    Jordan, Sue

    1997-01-01

    Using pharmacology case studies with nursing students encourages theory-practice links and infuses real-life content. Cases provide rich qualitative data for evaluating curriculum. However, they are not a substitute for evidence-based practice. (SK)

  6. Atmospheric chemistry: Laboratory studies of kinetics of important reactions

    NASA Astrophysics Data System (ADS)

    Smith, S. J.

    Experiments to measure the rate constants for some reactions of the atmospherically important nitrate radical (NO3) are described using the discharge-flow technique. The nitrate radical was monitored by optical absorption at lambda = 662 nm. The reactions of NO3 with some stable organic and inorganic substrates are reported. The temperature dependences of some of the rate constants were also determined (298 less than T less than 523 K). In most cases, computer simulation was used to extract the rate constant for the primary process because the time-dependent behavior of (NO3) was affected by secondary reactions of NO3 with products of the primary interaction. The Arrhenius parameter for the reactions of NO3 with CH3CH3, CH2CH2, CH3OH, CHCl3, and HCl were determined. The activation energies for the reactions studied between NO3 and some alkynes are presented along with the corresponding pre-exponential factors. Some reactions were studied at room temperature (298 plus or minus 2 K) only and the rate constants found (in units of cubic cm/molecule sec) are: buta-1,3-diene (1.8 x 10 (exp -13), isobutene (2.8 x 10 (exp -13), HBr (1.3 x 10 (exp -15) and hex-2-yne (3.0 x 10 (exp -14). Non-Arrhenius behavior was found in the reactions of NO3 with n-butane, isobutane and propene. The empirical variation of these rate constants with temperature is presented. The curvature of the Arrhenius plots is discussed in terms of (1) a temperature-dependent pre-exponential factor, and (2) the possibility that two competing channels, possessing differing activation energies, exist for each reaction. The atmospheric implications of these reactions are discussed with reference to the nighttime production of nitric acid and the importance of the these reactions as loss processes for NO3.

  7. Emotion, Engagement, and Case Studies

    ERIC Educational Resources Information Center

    Herreid, Clyde Freeman; Terry, David R.; Lemons, Paula; Armstrong, Norris; Brickman, Peggy; Ribbens, Eric

    2014-01-01

    Three college faculty taught large general biology classes using case studies and personal response systems (clickers). Each instructor taught the same eight cases in two different sections, except the questions within the cases differed. In one section the questions were lower order (LO) factual inquiries, and in the other they were largely…

  8. Case Study: Case Studies and the Flipped Classroom

    ERIC Educational Resources Information Center

    Herreid, Clyde Freeman; Schiller, Nancy A.

    2013-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue discusses the positive and negative aspects of the "flipped classroom." In the flipped classroom model, what is normally done in class and what is normally done as…

  9. Syncope: Case Studies.

    PubMed

    Kleyman, Inna; Weimer, Louis H

    2016-08-01

    Syncope, or the sudden loss of consciousness, is a common presenting symptom for evaluation by neurologists. It is not a unique diagnosis but rather a common manifestation of disorders with diverse mechanisms. Loss of consciousness is typically preceded by a prodrome of symptoms and sometimes there is a clear trigger. This article discusses several cases that illustrate the various causes of syncope. Reflex syncope is the most common type and includes neurally mediated, vasovagal, situational, carotid sinus hypersensitivity, and atypical forms. Acute and chronic autonomic neuropathies and neurodegenerative disorders can also present with syncope. PMID:27445240

  10. Studies of radiative transfer in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Schloerb, F. P.

    1986-01-01

    The research emphasis during the period of this report has been on radio observations of comets, related to the International Halley Watch. Observations of the 18 cm lambda-doublet of OH have been carried out monthly. Both of the 1667 and 1665 MHz lines have been repeatedly detected for Comets Halley, Giacobini-Zinner, Thiele, and Hartley-Good. The first astronomical detection of the weak satellite line at 1720 MHz was made for P/Halley. These data promise to supply the highest signal-to-noise-ratio data over an extended period ever obtained for cometary radio observations. Analysis will provide gas production rates as a function of heliocentric distance and allow for detailed comparisons with the OH excitation model involving ultraviolet pumping. In the case of Halley, the lines appear quite symmetric, usually being centered within 0.1 km/s with respect to the nominal nuclear velocity. Line widths have been typically within 10% of 2 km/s. There is thus little evidence for asymmetric emission in the data obtained to date. It seems likely that non-steady-state models of the coma will be required to interpret the data. Evidence for significant departures from the LTE hyperfine ratios was found for Comet Giacobini-Zinner. Smaller, but nonetheless significant, deviations have been found for Comet Halley.

  11. Ultrasonic nebulization atmospheric pressure glow discharge - Preliminary study

    NASA Astrophysics Data System (ADS)

    Greda, Krzysztof; Jamroz, Piotr; Pohl, Pawel

    2016-07-01

    Atmospheric pressure glow microdischarge (μAPGD) generated between a small-sized He nozzle jet anode and a flowing liquid cathode was coupled with ultrasonic nebulization (USN) for analytical optical emission spectrometry (OES). The spatial distributions of the emitted spectra from the novel coupled USN-μAPGD system and the conventional μAPGD system were compared. In the μAPGD, the maxima of the intensity distribution profiles of the atomic emission lines Ca, Cd, In, K, Li, Mg, Mn, Na and Sr were observed in the near cathode region, whereas, in the case of the USN-μAPGD, they were shifted towards the anode. In the novel system, the intensities of the analytical lines of the studied metals were boosted from several to 35 times. As compared to the conventional μAPGD-OES with the introduction of analytes through the sputtering and/or the electrospray-like nebulization of the flowing liquid cathode solution, the proposed method with the USN introduction of analytes in the form of a dry aerosol provides improved detectability of the studied metals. The detection limits of metals achieved with the USN-μAPGD-OES method were in the range from 0.08 μg L- 1 for Li to 52 μg L- 1 for Mn.

  12. Atmospheric reactivity studies of aliphatic amines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ambient studies of particulate matter have shown that alkyl amines are often present in particles in areas impacted by agricultural emissions. These locations include California’s Central Valley and Inland Empire and Utah’s Cache Valley. These compounds are not typically observed in airsheds that so...

  13. Three Community College Case Studies

    ERIC Educational Resources Information Center

    Wojtysiak, Joseph; Sutton, William J., II; Wright, Tommy; Brantley, Linda

    2011-01-01

    This article presents three case studies that focus on specific projects that are underway or have been completed. In the first case study, Joseph Wojtysiak and William J. Sutton, II discuss the Green Center of Central Pennsylvania, which is designed to serve as the state's preeminent source for education, training and public information about…

  14. The Big Read: Case Studies

    ERIC Educational Resources Information Center

    National Endowment for the Arts, 2009

    2009-01-01

    The Big Read evaluation included a series of 35 case studies designed to gather more in-depth information on the program's implementation and impact. The case studies gave readers a valuable first-hand look at The Big Read in context. Both formal and informal interviews, focus groups, attendance at a wide range of events--all showed how…

  15. Instructional Computing: Ten Case Studies.

    ERIC Educational Resources Information Center

    Hargan, Carol; Hunter, Beverly

    These case studies are written for educational institutions that wish to plan, extend, or improve their use of computers for learning and teaching. Each case study includes a brief description of each of the following: profile of the institution, history of the development of instructional computing, organization and management, student access to…

  16. Studies of radiative transfer in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Schloerb, F. P.

    1984-01-01

    Progress is reported in modeling cometary emission in the 18-cm OH transition with specific application and predictions for Comet Halley. Radiative transfer is also being studied in rough and porous media. The kinematics of the cold, dark interstellar cloud Li34N were examined, and CO monitoring of Venus and Mars continues. Analysis of 3.4 mm maps of the lunar surface shows thermal anomalies associated with such surface features as the Crater Copernicus, Mare Imbrium, Mare Nubium, Mare Serenitatis, and Mare Tranquillatis.

  17. Studies of radiative transfer in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Schloerb, F. P.

    1986-01-01

    Schloerb and Claussen continued their analysis of the very high quality data set obtained on the 18 centimeter OH line from the Comet P/Halley with the NRAO 43 meter antenna. The high spectral resolution (0.22 km/sec) and high signal-to-noise of the OH spectra make them ideal for the study of kinematics in the coma. Synthetic profiles were initiated for comparison with the data. A vectorial model was developed using the Monte Carlo techniques originated by Combi and Delsemme. Analysis of the millimeter wavelength observations of HCN emission from P/Halley obtained throughout much of the recent apparition were continued using the University of Massachusetts 14 millimeter-wavelength (FCRAO) antenna. A detailed analysis of the HCN lineshpaes was performed over the last six months. The excitation of HCN in the coma was studied to obtain a detailed match to the observed spectra. The passive millimeter wave radiometer was used to probe the physical and chemical nature of comets from spacecraft. Work was continued on an improved theory of radiative transfer for rough and porous surfaces, such as the regoliths of satellites, asteroids, and comets.

  18. Studies of Arctic Middle Atmosphere Chemistry using Infrared Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lindenmaier, Rodica

    small and in good agreement with previous ground-based FTIR/ACE-FTS comparisons. No clear bias was seen from year-to-year, and, in all cases, the difference between the measurements was within one standard deviation. The mean biases between the ACE-FTS and 125HR partial columns for 2007-2010 were -5.61 to 1.11%, -0.23 to 4.86%, -15.33 to -2.86%, -4.77 to 1.09%, and -0.34 to 5.23% for O3, HCl, ClONO2, HNO3, and HF, respectively. The 125HR measurements and three atmospheric models (CMAM-DAS, GEM-BACH, and SLIMCAT) were used to derive an NOy partial column data product for Eureka. This data product includes the five primary species NO, NO 2, HNO3, N2O5, and ClONO2 and was used to study the seasonal and interannual variability of NO y from 2007 to 2010. The NOy 15-40 km partial column was found to be approximately constant through the sunlit part of the year, with greater variability during the spring. The mean partial column averaged for the spring period was (2.5+/-0.2)x1016 molec cm -2, while for the summer, it was (2.3+/-0.1)x1016 molec cm-2. The springtime evolution of NOy and its constituent nitrogen species, was also examined for all four years. The variability of the 5-NOy partial column was seen to be dominated by that of HNO3. The evolution of the individual nitrogen species was found to be consistent with the current understanding of the chemical and dynamical processes that occur in the polar stratosphere. Unusually low ozone columns were measured at Eureka from mid-February to late March 2011 and compared to the previous 14 years of measurements by the 125HR and its predecessor, Environment Canada's Bomem DA8. The normalized O3/HF, HCl/HF, and HNO3/HF ratios, for which the effects of dynamics have been reduced, also showed record minima over this period. The SLIMCAT chemical transport model was used to quantify chemical ozone loss using the passive subtraction method. Chemical ozone depletion inside the vortex above Eureka was estimated to be 35%, which is the

  19. [Observational study of atmospheric HONO in summer of Beijing].

    PubMed

    Zhu, Yan-Wu; Liu, Wen-Qing; Xie, Pin-Hua; Dou, Ke; Liu, Shi-Sheng; Si, Fu-Qi; Li, Su-Wen; Qin, Min

    2009-06-15

    The concentration of HONO, NO2, O3 and other atmospheric pollutants were observed continuously by using differential optical absorption spectroscopy (DOAS) from 2007-08-14 to 2007-08-24 in Beijing, China. Diurnal variation characteristics of HONO and NO2 were analyzed. The HONO levels originated from the nocturnal direct emission were discussed. And the correlation between the heterogeneous formation of HONO and its related factors (BC, RH, and so on) was studied. The results showed that HONO had two peaks at about 01:00 and 06:00, respectively, while two peaks of NO2 concentrations appeared at about 01:00 and 07:00. The highest HONO(em)/HONO ratio of 31.3% was observed at about 20:00 between 19:00 to 07:00, and the average ratio was 15%. Good correlation of HONO(corr)/NO2 ratio with BC and RH at night was obtained. The correlation suggested that heterogeneous NO2 to HONO conversion processes may occur on BC surfaces by reaction with absorption water, and the average nighttime conversion frequency from NO2 into HONO (HONO/NO2) was calculated about 0.8% x h(-1). At the same time, the results showed that heterogeneous formation of HONO was increased with RH and inhibited at RH > 80%, and the hypothesis was further supported by detailed analysis of selected case. PMID:19662832

  20. Entropy studies on beam distortion by atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Wu, Chensheng; Ko, Jonathan; Davis, Christopher C.

    2015-09-01

    When a beam propagates through atmospheric turbulence over a known distance, the target beam profile deviates from the projected profile of the beam on the receiver. Intuitively, the unwanted distortion provides information about the atmospheric turbulence. This information is crucial for guiding adaptive optic systems and improving beam propagation results. In this paper, we propose an entropy study based on the image from a plenoptic sensor to provide a measure of information content of atmospheric turbulence. In general, lower levels of atmospheric turbulence will have a smaller information size while higher levels of atmospheric turbulence will cause significant expansion of the information size, which may exceed the maximum capacity of a sensing system and jeopardize the reliability of an AO system. Therefore, the entropy function can be used to analyze the turbulence distortion and evaluate performance of AO systems. In fact, it serves as a metric that can tell the improvement of beam correction in each iteration step. In addition, it points out the limitation of an AO system at optimized correction as well as the minimum information needed for wavefront sensing to achieve certain levels of correction. In this paper, we will demonstrate the definition of the entropy function and how it is related to evaluating information (randomness) carried by atmospheric turbulence.

  1. Industrial cogeneration case studies

    NASA Astrophysics Data System (ADS)

    Limaye, D. R.; Isser, S.; Hinkle, B.; Friedman, N. R.

    1980-09-01

    Studies were performed on a number of operating cogeneration systems to determine application, economics, and attitudes of industrial and utility executives toward cogeneration. A literature survey was conducted and an identification of candidate cogeneration sites was carried out. This was followed by a screening of these sites down to 20 to 30 candidate sites. The screening was carried out on the basis of cogeneration capacity, geographical diversity, generation type, and industrial diversity. The remaining sites were contacted as to their willingness to work with EPRI, and an industrial questionnaire was developed on technical, economic, and institutional cogeneration issues. Each of the seventeen sites was visited during this task. A utility questionnaire was developed and utilities with cogeneration systems studied in this survey were contacted as to their attitudes toward cogeneration. In addition, a compilation of a list of operating cogeneration systems was performed.

  2. The unified model, a fully-compressible, non-hydrostatic, deep atmosphere global circulation model, applied to hot Jupiters. ENDGame for a HD 209458b test case

    NASA Astrophysics Data System (ADS)

    Mayne, Nathan J.; Baraffe, Isabelle; Acreman, David M.; Smith, Chris; Browning, Matthew K.; Skålid Amundsen, David; Wood, Nigel; Thuburn, John; Jackson, David R.

    2014-01-01

    We are adapting the global circulation model (GCM) of the UK Met Office, the so-called unified model (UM), for the study of hot Jupiters. In this work we demonstrate the successful adaptation of the most sophisticated dynamical core, the component of the GCM which solves the equations of motion for the atmosphere, available within the UM, ENDGame (Even Newer Dynamics for General atmospheric modelling of the environment). Within the same numerical scheme ENDGame supports solution to the dynamical equations under varying degrees of simplification. We present results from a simple, shallow (in atmospheric domain) hot Jupiter model (SHJ), and a more realistic (with a deeper atmosphere) HD 209458b test case. For both test cases we find that the large-scale, time-averaged (over the 1200 days prescribed test period), dynamical state of the atmosphere is relatively insensitive to the level of simplification of the dynamical equations. However, problems exist when attempting to reproduce the results for these test cases derived from other models. For the SHJ case the lower (and upper) boundary intersects the dominant dynamical features of the atmosphere meaning the results are heavily dependent on the boundary conditions. For the HD 209458b test case, when using the more complete dynamical models, the atmosphere is still clearly evolving after 1200 days, and in a transient state. Solving the complete (deep atmosphere and non-hydrostatic) dynamical equations allows exchange between the vertical and horizontal momentum of the atmosphere, via Coriolis and metric terms. Subsequently, interaction between the upper atmosphere and the deeper more slowly evolving (radiatively inactive) atmosphere significantly alters the results, and acts over timescales longer than 1200 days. Figures 1, 4-8, 10 and 11 are available in electronic form at http://www.aanda.org

  3. Case Studies in Science Ethics

    NASA Astrophysics Data System (ADS)

    Williams, Karen

    2010-03-01

    Everyone in science should have ethics education training. I have seen graduate students taken advantage of by their mentors. Many of us have seen misconduct...but what should we do about it? Young scientists are often unaware of the rules in science and make mistakes because of their ignorance of the rules in that particular field of study. Then there are an increasing number of cases in the news of overt cases of misrepresentation in science. All are welcome to attend this discussion of case studies. A case study on topics such as: how to treat data properly, how our values in science affect our work, who gets authorship on scientific papers, who is first author on a paper, what you should do if you uncover misconduct or plagiarism in your university, and we will discuss the scientist's role in society. This will be a painless, non-confrontational small group, then large group discussion of each case

  4. ChEAS Data: The Chequamegon Ecosystem Atmosphere Study

    DOE Data Explorer

    Davis, Kenneth J. [Penn State

    The Chequamegon Ecosystem-Atmosphere Study (ChEAS) is a multi-organizational research effort studying biosphere/atmosphere interactions within a northern mixed forest in Northern Wisconsin. A primary goal is to understand the processes controlling forest-atmosphere exchange of carbon dioxide and the response of these processes to climate change. Another primary goal is to bridge the gap between canopy-scale flux measurements and the global CO2 flask sampling network. The ChEAS flux towers participate in AmeriFlux, and the region is an EOS-validation site. The WLEF tower is a NOAA-CMDL CO2 sampling site. ChEAS sites are primarily located within or near the Chequamegon-Nicolet National Forest in northern Wisconsin, with one site in the Ottawa National Forest in the upper peninsula of Michigan. Current studies observe forest/atmosphere exchange of carbon dioxide at canopy and regional scales, forest floor respiration, photosynthesis and transpiration at the leaf level and use models to scale to canopy and regional levels. EOS-validation studies quantitatively assess the land cover of the area using remote sensing and conduct extensive ground truthing of new remote sensing data (i.e. ASTER and MODIS). Atmospheric remote sensing work is aimed at understanding atmospheric boundary layer dynamics, the role of entrainment in regulating the carbon dioxide mixing ratio profiles through the lower troposphere, and feedback between boundary layer dynamics and vegetation (especially via the hydrologic cycle). Airborne studies have included include balloon, kite and aircraft observations of the CO2 profile in the troposphere.

  5. Study of the Martian upper atmosphere using radio tracking data

    NASA Astrophysics Data System (ADS)

    Mazarico, Erwan

    Since the first in situ observations of the Martian atmosphere were made by the twin Viking landers, we have learned considerably more about its composition, dynamics and variability. Not only did the new data on global atmospheric densities generate opportunities to understand the atmospheric composition of early Mars and supply constraints at the upper limit of General Circulation Models, it is critical for the design and planning of future exploration missions. We can complement the successes of remote sensing and accelerometer investigations by using radio tracking data that have not been studied from an atmospheric science perspective, or are available for the first time. Due to the very low density of the higher layers atmosphere, the estimation of the drag acceleration using Precision Orbit Determination is a challenge. We developed new numerical models of the non-conservative forces acting on the spacecraft. In particular, the spacecraft cross-sectional area is calculated using improved spacecraft macro-models which include inter-plate shadowing. These improvements in the force modeling enable a more robust estimation of the atmospheric density. The density structure from the middle atmosphere up to the exosphere is studied using radio tracking data from the Mars Odyssey and the Mars Reconnaissance Orbiter spacecraft. Measurements in the Martian middle atmosphere, near 100-110 km, are obtained from the aerobraking phase of the Mars Odyssey spacecraft; we obtain periapsis density estimates consistent with the Accelerometer Team, and estimate scale heights representative of the drag environment from an operational point of view. The orbit of Mars Odyssey during its mapping and extended phases allows us to probe very high in the exosphere, near 400 km altitude. In the retrieved density time series, we observe some of the features of solar forcing and seasonal cycle predicted by different atmospheric models. The most recent radio tracking data, from the Mars

  6. A Study on Planetary Atmospheric Circulations using THOR

    NASA Astrophysics Data System (ADS)

    Mendonça, João; Grosheintz, Luc; Lukas Grimm, Simon; Heng, Kevin

    2015-12-01

    The large variety of planetary parameters observed leads us to think that exoplanets may show a large range of possible climates. It is therefore of the uttermost importance to investigate the influence of astronomical and planetary bulk parameters in driving the atmospheric circulations. In the solar system the results from planetary spacecraft missions have demonstrated how different the planetary climate and atmospheric circulations can be. The study of exoplanets will require probing a far wider range of physical and orbital parameters than the ones of our neighbor planets. For this reason, such a study will involve exploring an even larger diversity of circulation and climate regimes. Our new atmospheric model, THOR, is intended to be extremely flexible and to explore the large diversity of planetary atmospheres.THOR is part of the Exoclimes Simulation Platform, and is a project of the Exoplanet and Exoclimes Group (see www.exoclime.org). THOR solves the complex atmospheric fluid equations in a rotating sphere (fully compressible - nonhydrostatic system) using an icosahedral grid. The main advantages of using our new platform against other recent exoplanet models is that 1) The atmospheric fluid equations are completely represented and no approximations are used that could compromise the physics of the problem; 2) The model uses for the first time in exoplanet studies, a specific icosahedral grid that solves the pole problem; 3) The interface is user friendly and can be easily adapted to a multitude of atmospheric conditions; 4) By using GPU computation, our code greatly improves the typical code running time.We will present and discuss the first detailed results of our simulations, more specifically of two benchmark tests that are a representative sample of the large range of exoplanetary parameters: Earth-like conditions (the Held-Suarez test) and a tidally locked hot-Jupiter. THOR has successfully passed these tests and is able to determine the main

  7. Work Teams: A Case Study.

    ERIC Educational Resources Information Center

    Fisher, M. Scott

    1981-01-01

    An important aspect of work environment is job content and structure. As this case study illustrates, increased productivity, enhanced job satisfaction, substantial cost reduction, and a reduction in turnover are some of the benefits of task reorganization. (CT)

  8. Teaching astronomy with case studies

    NASA Astrophysics Data System (ADS)

    Slater, Timothy F.

    2015-11-01

    Breaking the students into small, collaborative learning groups to solve a meaningful task together is one of the most successful and fully evaluated teaching techniques implemented over the last century. Although there are many ways to accomplish small group learning, a long-standing and consistently successful collaborative class activity is to use the case study teaching strategy. The use of case studies is common in medical schools and law schools, but not so common in the teaching of astronomy. Case studies create meaningful conversations among students and with the professor by focusing on life-like dilemmas to be solved. Case study tasks ask audience members to synthesize several ideas or evaluate scenarios that have not been explicitly presented to them in the lecture or in available readings.

  9. Case Study: del Amo Bioventing

    EPA Science Inventory

    The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.

  10. Hydrogeologic Case Studies (Seattle, WA)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  11. HYDROGEOLOGIC CASE STUDIES (CHICAGO, IL)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  12. HYDROGEOLOGIC CASE STUDIES (DENVER PRESENTATION)

    EPA Science Inventory

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  13. Nasopharyngeal Case-Control Study

    Cancer.gov

    A case-control study conducted in Taiwan between 1991-1994 among approximately 1,000 individuals to examine the role of viral, environmental, and genetic factors associated with the development of nasopharyngeal carcinoma

  14. A comparative study of atmospheric corrosion in the Caribbean area

    SciTech Connect

    Maldonado, L.; Castro, P.; Echeverria, M.

    1995-10-01

    Atmospheric corrosion is a phenomenon of such a magnitude that has been cause of study in several countries for decades. Nevertheless, in Mexico, it became of recent interest due to new economic factors that have involved the Peninsula of Yucatan too. The Yucatan Peninsula is limited to the North and West by the Gulf of Mexico and to the East by the Caribbean Sea. This is a non industrialized region so that in the past very little importance was given to the atmospheric corrosion damage or to the quantification of the high corrosion rates, empirically observed. However, in recent times increased tourism, industrial growth and petroleum extraction have exhibited the need for a better understanding of the atmospheric corrosion processes, as well as a realistic correlation to parameters such as time-of-wetness, levels of pollution by airborne salinity, atmospheric S0{sub 2} and corrosivity categories for the metals. To evaluate these parameters, five tests sites were selected following ISO recommendations. Three sites are marines atmospheres, one urban and one rural. Corrosion rates for commercial laminated Cu and carbon steel, as well as deposition rates of pollutants, were determined after one year exposure in the test sites. Applying the standard practice ISO 9223 a categorization of the corrosivity and of the level of pollutants was carried out. The marine environments were classified as of atmospheric corrosivity C{sub 5}, while the urban and the rural could be classified as C{sub 3}, respectively. The pollution values showed that the exposure sites were essentially contaminated with chloride with classification S{sub 1} for the rural site and S{sub 3} for the marine atmosphere.

  15. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. I. PHOTOCHEMISTRY MODEL AND BENCHMARK CASES

    SciTech Connect

    Hu Renyu; Seager, Sara; Bains, William

    2012-12-20

    We present a comprehensive photochemistry model for exploration of the chemical composition of terrestrial exoplanet atmospheres. The photochemistry model is designed from the ground up to have the capacity to treat all types of terrestrial planet atmospheres, ranging from oxidizing through reducing, which makes the code suitable for applications for the wide range of anticipated terrestrial exoplanet compositions. The one-dimensional chemical transport model treats up to 800 chemical reactions, photochemical processes, dry and wet deposition, surface emission, and thermal escape of O, H, C, N, and S bearing species, as well as formation and deposition of elemental sulfur and sulfuric acid aerosols. We validate the model by computing the atmospheric composition of current Earth and Mars and find agreement with observations of major trace gases in Earth's and Mars' atmospheres. We simulate several plausible atmospheric scenarios of terrestrial exoplanets and choose three benchmark cases for atmospheres from reducing to oxidizing. The most interesting finding is that atomic hydrogen is always a more abundant reactive radical than the hydroxyl radical in anoxic atmospheres. Whether atomic hydrogen is the most important removal path for a molecule of interest also depends on the relevant reaction rates. We also find that volcanic carbon compounds (i.e., CH{sub 4} and CO{sub 2}) are chemically long-lived and tend to be well mixed in both reducing and oxidizing atmospheres, and their dry deposition velocities to the surface control the atmospheric oxidation states. Furthermore, we revisit whether photochemically produced oxygen can cause false positives for detecting oxygenic photosynthesis, and find that in 1 bar CO{sub 2}-rich atmospheres oxygen and ozone may build up to levels that have conventionally been accepted as signatures of life, if there is no surface emission of reducing gases. The atmospheric scenarios presented in this paper can serve as the benchmark

  16. Polarimetic Study of Atmospheric Phenomena and Its Applications

    NASA Astrophysics Data System (ADS)

    Yanamandra-Fisher, P. A.

    2015-12-01

    Polarized light occurs in three states: unpolarized, linear and circularized. Each mode of polarized light provides information about the scattering medium, from atmospheres to search for signatures of habitability. Linear polarization in the optical and near-infrared windows are optimum to study changes in cloud/hazes in planetary atmospheres. Circular polarization is important to understand the influence of multiple scattering in the atmosphere. Linear and circular polarization of comets provides information about the composition and wavelength dependence of the dust, indicative of new, active comets vs. older comets. Changes in magnetic fields (as in aurorae) can be explored with polarimetry. Atmospheric phenomena such as rainbows,clouds and haloes exhibit polarimetric signatures that can be used as diagnostics to probe the atmosphere and may be possible to extend this approach to other planets and exoplanets. Biological molecules exhibit an inherent handedness or circular polarization or chirality, assisting in search for the identification of astrobiological material in the solar system. I shall highlight observations and models for these phenomena.

  17. Theoretical and experimental studies of the atmospheric sodium layer

    NASA Technical Reports Server (NTRS)

    Richter, E. S.; Sechrist, C. F., Jr.

    1978-01-01

    Atmospheric atomic sodium was studied with a laser radar system. Photocount data were processed using a digital filter to obtain continuous estimates of the sodium concentration versus altitude. Wave-like structures in the sodium layer were observed, and there was evidence for the presence of a standing wave in the layer. The bottomside of the layer was observed to undulate with a period of about 2 1/2 hours, and the layer was observed to broaden through the night. A meteor ablation-cluster ion theory of sodium was developed. The theory shows good agreement with existing atmospheric observations as well as laboratory measurements of rate constants.

  18. Studying the Atmospheres of the Most Intriguing WASP Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Lendl, M.; Delrez, L.; Gillon, M.; Queloz, D.

    2013-09-01

    Among the over 300 transiting planets confirmed to date, approximately 130 have been found by groundbased wide angle transit surveys such asWASP. While these surveys are not sensitive enough to detect lowmass planets, they excel at picking out rare hot- Jupiters orbiting reasonably bright stars (V mag = 9 - 11) across the sky. These planets occupy a favorable region in parameter space, as they show frequent and deep transits. Due to the proximity to their host stars these gas giants possess hot extended atmospheres making them ideal targets for the study of their atmospheres via transmission and occultation spectrophotometry. During occultation, the flux emerging from the planetary dayside is eliminated. By comparing the flux in- and out-of occultation, the planet-to-star brightness ratio can be measured. Observations in different passbands yield a measure of the planetary spectral energy distribution and thereby allow to determine the atmospheric temperature structure, heat redistribution efficiency, albedo, and to place constraints on the atmospheric composition. From the spectro-photometric observation of transits, we can measure wavelength dependencies in the effective planetary radius that are sensitive to signatures of chemical elements in the planetary atmosphere. We present results of ongoing observing campaigns employing these methods to study the atmospheres of hot Jupiters discovered by the WASP survey. In particular we show results for the very short-period planet WASP-19b based on data from the 1m-class Euler-Swiss and TRAPPIST telescopes, as well as a transmission spectrum of the low-density hot Saturn WASP-49b obtained from FORS2 at the VLT/UT1.

  19. Low-level atmospheric flows studied by pulsed Doppler lidar

    NASA Technical Reports Server (NTRS)

    Banta, Robert M.; Olivier, Lisa D.; Hardesty, R. Michael

    1992-01-01

    A pulsed Doppler radar gains a tremendous advantage in studying atmospheric flows when it has the ability to scan. The Wave Propagation Laboratory (WPL) has been operating a scanning, 10.59 micron CO2 system for over 10 years. Recently, the WPL lidar has been a featured instrument in several investigations of mesoscale wind fields in the lowest 3-4 km of the atmosphere. These include four experiments: a study of the initiation and growth of the sea breeze off the coast of California, a study of the snake column of a prescribed forest fire, a study of the nighttime flow over the complex terrain near Rocky Flats, Colorado as it affects the dispersion of atmospheric contaminants, and a study of the wind flow in the Grand Canyon. We have analyzed much data from these experiments, and we have found that the lidar provides new insight into the structure of these flows. Many of these studies took place in rugged or mountainous terrain, thus using one of the major benefits of the lidar: the narrow, 90 microrad beam of the lidar makes it an ideal instrument for studying flow close to topography.

  20. Critical review of studies on atmospheric dispersion in coastal regions

    SciTech Connect

    Shearer, D.L.; Kaleel, R.J.

    1982-09-01

    This study effort was required as a preliminary step prior to initiation of field measurements of atmospheric dispersion in coastal regions. The Nuclear Regulatory Commission (NRC) is in the process of planning an extensive field measurement program to generate data which will serve as improved data bases for licensing decisions, confirmation of regulations, standards, and guides, and for site characterizations. The study being reported here is an effort directed to obtaining as much information as is possible from existing studies that is relevant toward NRC's objectives. For this study, reports covering research and meteorological measurements conducted for industrial purposes, utility needs, military objectives, and academic studies were obtained and critically reviewed in light of NRC's current data needs. This report provides an interpretation of the extent of existing usable information, an indication of the potential for tailoring existing research toward current NRC information needs, and recommendations for several follow-on studies which could provide valuable additional information through reanalysis of the data. Recommendations are also offered regarding new measurement programs. Emphasis is placed on the identification and acquisition of data from atmospheric tracer studies conducted in coastal regions. A total of 225 references were identified which deal with the coastal atmosphere, including meteorological and tracer measurement programs, theoretical descriptions of the relevant processes, and dispersion models.

  1. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    SciTech Connect

    Hopke, P.K.

    1992-07-01

    This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny's atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.

  2. A summary of the Lake Tahoe Atmospheric Deposition Study (LTADS)

    NASA Astrophysics Data System (ADS)

    Dolislager, Leon J.; VanCuren, Richard; Pederson, James R.; Lashgari, Ash; McCauley, Eileen

    2012-01-01

    The Lake Tahoe Atmospheric Deposition Study (LTADS) was conducted by the California Air Resources Board (CARB) primarily to generate refined estimates of the atmospheric deposition of nitrogen (N), phosphorous (P), and particulate matter (PM) directly to Lake Tahoe, which straddles the boundary between the states of California and Nevada in the United States of America. LTADS estimated that approximately 185, 3, and 755 metric tons respectively of N, P, and PM being directly deposited to the lake from the atmosphere. Various measurements of emissions, meteorology, and air quality were made within and west (typically upwind) of the Lake Tahoe Air Basin to better understand the pollutant sources contributing to the atmospheric deposition. The data indicate that ammonia (NH 3) contributes the bulk of the N loading. Aerosols with diameters greater than 2.5 μm contribute the bulk of the P and PM mass loadings. The emission sources of P and PM appear to be primarily local and associated with motor vehicles. However, construction, fires, and natural sources also contribute to the pollutant loadings. LTADS was part of a much larger research program to guide efforts to restore the remarkable water clarity of Lake Tahoe.

  3. CFD Simulations of Joint Urban Atmospheric Dispersion Field Study

    SciTech Connect

    Lee, R; Humphreys III, T; Chan, S

    2004-06-17

    The application of Computational Fluid Dynamics (CFD) to the understanding of urban wind flow and dispersion processes has gained increasing attention over recent years. While many of the simpler dispersion models are based on a set of prescribed meteorology to calculate dispersion, the CFD approach has the ability of coupling the wind field to dispersion processes. This has distinct advantages when very detailed results are required, such as for the case where the releases occur around buildings and within urban areas. CFD also has great flexibility as a testbed for turbulence models, which has important implications for atmospheric dispersion problems. In the spring of 2003, a series of dispersion field experiments (Joint Urban 2003) were conducted at Oklahoma City (Allwine, et. al, 2004). These experiments were complimentary to the URBAN 2000 field studies at Salt Lake City (Shinn, et. al, 2000) in that they will provide a second set of comprehensive field data for evaluation of CFD as well as for other dispersion models. In contrast to the URBAN 2000 experiments that were conducted entirely at night, these new field studies took place during both daytime and nighttime thus including the possibility of convective as well as stable atmospheric conditions. Initially several CFD modeling studies were performed to provide guidance for the experimental team in the selection of release sites and in the deployment of wind and concentration sensors. Also, while meteorological and concentration measurements were taken over the greater Oklahoma City urban area, our CFD calculations were focused on the near field of the release point. The proximity of the source to a large commercial building and to the neighboring buildings several of which have multistories, present a significant challenge even for CFD calculations involving grid resolutions as fine as 1 meter. A total of 10 Intensive Observations Periods (IOP's) were conducted within the 2003 field experiments. SF6

  4. Teaching Case: Enterprise Architecture Specification Case Study

    ERIC Educational Resources Information Center

    Steenkamp, Annette Lerine; Alawdah, Amal; Almasri, Osama; Gai, Keke; Khattab, Nidal; Swaby, Carval; Abaas, Ramy

    2013-01-01

    A graduate course in enterprise architecture had a team project component in which a real-world business case, provided by an industry sponsor, formed the basis of the project charter and the architecture statement of work. The paper aims to share the team project experience on developing the architecture specifications based on the business case…

  5. A Comparative Study of Super-Earth Atmospheres

    NASA Astrophysics Data System (ADS)

    Dragomir, Diana; Benneke, Bjoern; Crossfield, Ian; Howard, Andrew; Knutson, Heather

    2014-12-01

    Ongoing transit surveys such as Kepler have resulted in the discovery of more than a dozen super?Earth planets with measured masses and radii. These planets are challenging targets for atmospheric characterization studies, and to date only one (GJ 1214b) has been studied in detail. In this proposal we focus on three additional super-Earths that are amenable to transmission spectroscopy studies due to their bright host stars (HD 97658b and 55 Cnc e) or their exceptionally low density (Kepler-138d). Our Spitzer measurements of these planets' transit depths will complement our already approved HST observations and contribute to distinguishing between clear hydrogen?dominated atmospheres and compact high-metallicity atmospheres, as well as constraining the composition of any high-altitude clouds. We will also search for evidence of carbon-bearing molecules, in particular for 55 Cnc e, a planet for which a carbon-rich composition has been suggested. Our observations will probe the poorly understood transition region between gas giant planets and terrestrial worlds, and provide constraints on the formation regions of these super-Earths. The results of this program will inform the direction to be taken by large-scale studies of these worlds with JWST.

  6. Atmospheric Chemistry: Laboratory Studies of Kinetics of Important Reactions.

    NASA Astrophysics Data System (ADS)

    Smith, S. J.

    Available from UMI in association with The British Library. Requires signed TDF. This thesis describes the experiments to measure the rate constants for some reactions of the atmospherically important nitrate radical (NO_3) using the discharge-flow technique. The nitrate radical was monitored by optical absorption at lambda = 662 nm. The reactions of NO_3 with some stable organic and inorganic substrates are reported. The temperature dependences of some of the rate constants have also been determined (298 < T < 523 K). In most cases, computer simulation was used to extract the rate constant for the primary process because the time-dependent behaviour of (NO_3) was affected by secondary reactions of NO_3 with products of the primary interaction. The Arrhenius parameter in parentheses (E _{rm a}/kJ mol^ {-1}, A/cm^3 molecule ^{-1}s^ {-1} respectively) for the following reactions have been determined: ethane (37, 6.7 times 10^{-12}), ethylene (25.8, 6.3 times 10^ {-12}), CH_3OH (21.3, 1.2 times 10^ {-12}), CHCiota_3 (23.4, 8.6 times 10 ^{-13}) and HCl (27.7, 4 times 10^{-12}). The activation energies for the reactions studied between NO_3 and some alkynes are represented well by the value 25 +/- 3 kJ mol^{-1} and the corresponding pre-exponential factors (expressed as ln(10 ^{13}A/cm^3 molecule^{-1}s ^{-1}) are as follows: C_2H_2 (1.6 +/- 1.4), C_3H _4 (5.0 +/- 1.4), 1-C_4H_6 (5.8 +/- 1.0), 1-C_5 H_8 (5.7 +/- 0.6) and 1-C_6H _{10} (4.5 +/- 0.4). Some reactions were studied at room temperature _3(298 +/- 2 K) only and the rate constants found (in units of cm ^3 molecule^{ -1}s^{-1}) are: buta-1,3-diene (1.8 times 10 ^{-13}), isobutene (2.8 times 10^{-13 }), HBr (1.3 times 10 ^{-15}) and hex-2-yne (3.0 times 10^{-14 }). Non-Arrhenius behaviour was found in the reactions of NO_3 with n-butane, isobutane and propene. The empirical variation of these rate constants with temperature is well represented by the three parameter expressions:. k(T) = 1.2 times 10 ^{-46}T^{11

  7. Numerical Study of the Effects of Atmospheric and Wake Turbulence on Wind Turbine Dynamics

    SciTech Connect

    Churchfield, M. J.; Lee, S.; Michalakes, J.; Moriarty, P. J.

    2012-01-01

    Although the atmospheric sciences community has been studying the effects of atmospheric stability and surface roughness on the planetary boundary layer for some time, their effects on wind turbine dynamics have not been well studied. In this study, we performed numerical experiments to explore some of the effects of atmospheric stability and surface roughness on wind turbine dynamics. We used large-eddy simulation to create atmospheric winds and compute the wind turbine flows, and we modeled the wind turbines as revolving and flexible actuator lines coupled to a wind turbine structural and system dynamic model. We examined the structural moments about the wind turbine blade, low-speed shaft, and nacelle; power production; and wake evolution when large 5-MW turbines are subjected to winds generated from low- and high-surface roughness levels representative of offshore and onshore conditions, respectively, and also neutral and unstable atmospheric conditions. In addition, we placed a second turbine 7 rotor diameters downwind of the first one so that we could explore wake effects under these different conditions. The results show that the turbulent structures generated within the atmospheric boundary layer wind simulations cause isolated loading events at least as significant as when a turbine is waked by an upwind turbine. The root-mean-square (RMS) turbine loads are consistently larger when the surface roughness is higher. The RMS blade-root out-of-plane bending moment and low-speed shaft torque are higher when the atmospheric boundary layer is unstable as compared with when it is neutral. However, the RMS yaw moments are either equal or reduced in the unstable case as compared with the neutral case. For a given surface roughness, the ratio of power produced by the downwind turbine relative to that of the upwind turbine is 15-20% higher when the conditions are unstable as compared with neutral. For a given atmospheric stability, this power ratio is 10% higher with

  8. A study of atmospheric neutrinos with the IMB detector

    NASA Technical Reports Server (NTRS)

    Losecco, J. M.; Bionta, R. M.; Blewitt, G.; Bratton, C. B.; Casper, D.; Chrysicopoulou, P.; Claus, R.; Cortez, B. G.; Errede, S.; Foster, G. W.

    1985-01-01

    A sample of 401 contained neutrino interactions collected in the 3300 metric ton fiducial mass IMB detector was used to study neutrino oscillations, geomagnetic modulation of the flux and to search for point sources. The majority of these events are attributed to neutrino interactions. For the most part, these neutrinos are believed to originate as tertiary products of cosmic ray interactions in the atmosphere. The neutrinos are a mixture of v sub e and v sub micron.

  9. Case Studies in Broadcast Management.

    ERIC Educational Resources Information Center

    Coleman, Howard W.

    This collection of case studies, based on factual situations which have challenged broadcast managers in recent years, is designed to stimulate thinking about and solving of "real world" problems in commercial radio and television operations. Topics of a serious, long-run nature include enlarging the radio audience; station revenue and economy;…

  10. Case Studies in Sports Nutrition.

    ERIC Educational Resources Information Center

    Clark, Nancy

    1988-01-01

    This article presents case studies of two athletes who wanted to affect a change in their body weight in order to enhance athletic performance. Each athlete's problem and the nutrition approach used to solve it are discussed. Caloric values of fast foods are listed. (JL)

  11. Principal Succession: A Case Study.

    ERIC Educational Resources Information Center

    Jones, Jeffery C.; Webber, Charles F.

    Principal succession is misunderstood and underutilized as a means of affecting dynamic renewal in school communities. Previously, the replacement of a principal was examined solely through the experiences of principals and teachers. This paper reports on a case study that added the previously neglected perspectives of students, support staff, and…

  12. The Language Dilemma: Case Study.

    ERIC Educational Resources Information Center

    Teboul, J. C. Bruno

    2002-01-01

    Presents the case study involving a fictitious company's English-only policy and threats of legal action based on that policy. Includes the following responses: "Legal Issues Posed in the Language Dilemma" (Gregory S. Walden); "English Only: A Workplace Dilemma" (Alan Pakiela); "Problems with English-Only Policies" (Barbara Lynn Speicher); and…

  13. INNOVATIVE CLEAN TECHNOLOGIES CASE STUDIES

    EPA Science Inventory

    The Innovative Clean Technologies case studies contained herein are the products of the "Pollution Prevention by and for Small Business" Program (P2SB). he P2SB was an outreach program directed to small businesses that had developed innovative concepts for pollution prevention in...

  14. Due Process Hearing Case Study

    ERIC Educational Resources Information Center

    Bateman, David F.; Jones, Marni Gail

    2010-01-01

    This article presents a due process hearing case study of a mother who contended that his son, D.J., has been denied of a free and appropriate public education (FAPE) of his School District after being suspended from school. D.J., an elementary student, had been described as hyperactive, inattentive, defiant, and often volatile. He was identified…

  15. Case Study: Planning as Learning

    ERIC Educational Resources Information Center

    Smith, Peter A. C.

    2007-01-01

    Proposes that the objectives of strategic planning may be attained more effectively if implemented via a learning paradigm. In support of this claim, describes a case study detailing implementation of such an initiative plus post-implementation interviews. (Contains 5 figures.)

  16. State Planning System. Case Studies.

    ERIC Educational Resources Information Center

    Cherin, Ellen, Ed.

    The State Planning System (SPS) is a policy-oriented management tool intended to help analyze the interrelated effects of alternative policies and their relationships to state goals. Two pilot-test case studies are described--the SPS tuition policy evaluation conducted in Colorado, and New York's SPS evaluation of the applicability of large scale…

  17. Case Studies in Applied Mathematics.

    ERIC Educational Resources Information Center

    Mathematical Association of America, Washington, DC.

    This collection of nine case studies in applied mathematics was written primarily for the use of the instructor by a Conference sponsored by the Committee on the Undergraduate Program in Mathematics (CUPM). Each chapter contains exercises of varying degrees of difficulty and several include student projects. The materials were used on a trial…

  18. Ultra fined-grained atmospheric particulate studied by magnetic analysis

    NASA Astrophysics Data System (ADS)

    Saragnese, F.; Lanci, L.; Lanza, R.

    2009-04-01

    We present the result of an investigation on the presence of ultrafine atmospheric particulate in the urban area of Turin by magnetic methods. Magnetic minerals are a common component of atmospheric particulate, mostly arising from a number of anthropogenic activities. Atmospheric particulate is well known to represent a serious health problem in urban area and recently the attention focused especially on fine (< 2.5 μm) and ultrafine (< 0.1 m) particulates which are proven to be particularly dangerous because if inhaled they penetrate deep and reach lungs alveoli. In the last few years number studies took advantage of magnetic techniques to successfully identify atmospheric particulate matter through the magnetic analysis, however they did not draw much attention to the grain size problem. Indeed magnetic techniques have the ability to distinguish very fine-grained material by using the thermal relaxation effect and thus they potentially constitute a useful analysis tool to recognize ultrafine fractions of atmospheric particulate. We have performed low and room temperature isothermal remanent magnetization (IRM) and hysteresis loop measurements on atmospheric particulate samples in order to estimate the concentration of fine and ultrafine particles. Magnetic mineralogy was studied using IRM at room and liquid nitrogen temperature. Low temperature hysteresis and thermomagnetic curves were used study the grain size distribution that showed the presence of a mixture of low-coercivity particles, magnetite-like, and a variable grain-size populations. Samples were taken from filters collecting particulates matter with diameter < 10 µm (PM10) in different city areas, the particulate mass on the filter was also measured. Results confirm the general correlation between magnetization and concentration of particulate in air. The comparison between suburban and high-traffic area also support the previous finding that anthropogenic particulate has a large concentration of

  19. Atmosphere

    NASA Astrophysics Data System (ADS)

    Ghosh, D.; Mitra, S. K.

    2014-05-01

    This paper investigates the high-temperature corrosion behavior of microstructurally different regions of the weldment of 9 Cr-1 Mo steel used in thermal power plant boiler in SO2 + O2 environment. The weldment is produced by tungsten inert gas welding method, and the different regions of the weldment (weld metal, heat-affected zone, and base metal) are exposed in SO2 + O2 (ratio 2:1) environment at 973 K for 120 h. The reaction kinetics and corrosion growth rate of different regions of weldment in isothermal condition are evaluated. The post corroded scales of the different specimens are studied in SEM, EDS, and XRD. The results indicate that the weld metal shows higher corrosion rate followed by HAZ and base metal. The higher rate of corrosion of weldmetal is mainly attributed to the least protective inner scale of Cr2O3 with minimum Cr Content. This is due to the formation of delta ferrite, which leads to the precipitation of the Cr-based secondary phases and depletes the free Cr from the matrix. The thermal cycles during welding at high temperature are favorable for the formation of delta ferrite. On the other hand, in absence of delta ferrite, the base metal and HAZ regions of the weldment show lower corrosion rate than weld metal. The difference in corrosion rate in the three regions of the weldment is supplemented by post-corroded scale characterizations.

  20. Remote sensing for studying atmospheric aerosols in Malaysia

    NASA Astrophysics Data System (ADS)

    Kanniah, Kasturi D.; Kamarul Zaman, Nurul A. F.

    2015-10-01

    The aerosol system is Southeast Asia is complex and the high concentrations are due to population growth, rapid urbanization and development of SEA countries. Nevertheless, only a few studies have been carried out especially at large spatial extent and on a continuous basis to study atmospheric aerosols in Malaysia. In this review paper we report the use of remote sensing data to study atmospheric aerosols in Malaysia and document gaps and recommend further studies to bridge the gaps. Satellite data have been used to study the spatial and seasonal patterns of aerosol optical depth (AOD) in Malaysia. Satellite data combined with AERONET data were used to delineate different types and sizes of aerosols and to identify the sources of aerosols in Malaysia. Most of the aerosol studies performed in Malaysia was based on station-based PM10 data that have limited spatial coverage. Thus, satellite data have been used to extrapolate and retrieve PM10 data over large areas by correlating remotely sensed AOD with ground-based PM10. Realising the critical role of aerosols on radiative forcing numerous studies have been conducted worldwide to assess the aerosol radiative forcing (ARF). Such studies are yet to be conducted in Malaysia. Although the only source of aerosol data covering large region in Malaysia is remote sensing, satellite observations are limited by cloud cover, orbital gaps of satellite track, etc. In addition, relatively less understanding is achieved on how the atmospheric aerosol interacts with the regional climate system. These gaps can be bridged by conducting more studies using integrated approach of remote sensing, AERONET and ground based measurements.

  1. Radio Occultation Studies of Venus' Atmosphere with Magellan

    NASA Astrophysics Data System (ADS)

    Jenkins, Jon M.

    1998-01-01

    We have been conducting a systematic study of the middle and lower atmosphere of Venus through analysis of 20 radio occultation experiments conducted with the Magellan spacecraft between October, 1991, and August, 1994. These studies have revealed a rich but sparsely sampled trove of information regarding the structure, composition and dynamics of the Venus atmosphere. The five sets of experiments sampled a variety of latitudes. Basic results include vertical profiles of: (1) electron density in the ionosphere, (2) pressure, temperature, density, and static stability in the neutral atmosphere (from 33 km to 98 km), and (3) sulfuric acid vapor (H2SO4) abundance below the main cloud deck. Further analysis of the temperature profiles led to the discovery of small vertical-scale gravity waves in the neutral atmosphere. The retrieved profiles show intriguing zonal variations that might be due to planetary- scale waves. During the performance period of this grant, we have concentrated on reanalyzing the 15 experiments conducted in 1994 using improved trajectory files for Magellan provided by JPL, obtaining more reliable results, and on conducting an error analysis of the derived profiles. In addition, we have begun an analysis of microwave emission maps of Venus obtained at the Very Large Array (VLA) in April, 1996. This report is organized as follows: A summary of results is presented, giving representative examples of the various physical profiles retrieved from all the Magellan radio occultation studies, emphasizing latitudinal variations evident in the data. Next, a preliminary analysis of the VLA maps is given. A summary of activities follows the scientific results, detailing papers published and presented at various conferences. This report concludes with a "Conclusions and Suggestions for Future Work" section.

  2. Collected Data of The Boreal Ecosystem and Atmosphere Study (BOREAS)

    NASA Technical Reports Server (NTRS)

    Newcomer, J. (Editor); Landis, D. (Editor); Conrad, S. (Editor); Curd, S. (Editor); Huemmrich, K. (Editor); Knapp, D. (Editor); Morrell, A. (Editor); Nickerson, J. (Editor); Papagno, A. (Editor); Rinker, D. (Editor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) was a large-scale international interdisciplinary climate-ecosystem interaction experiment in the northern boreal forests of Canada. Its goal was to improve our understanding of the boreal forests -- how they interact with the atmosphere, how much CO2 they can store, and how climate change will affect them. BOREAS wanted to learn to use satellite data to monitor the forests, and to improve computer simulation and weather models so scientists can anticipate the effects of global change. This BOREAS CD-ROM set is a set of 12 CD-ROMs containing the finalized point data sets and compressed image data from the BOREAS Project. All point data are stored in ASCII text files, and all image and GIS products are stored as binary images, compressed using GZip. Additional descriptions of the various data sets on this CD-ROM are available in other documents in the BOREAS series.

  3. Atmospheric heating of meteorites: Results from nuclear track studies

    NASA Technical Reports Server (NTRS)

    Jha, R.

    1984-01-01

    A quantitative model to estimate the degree of annealing of nuclear tracks in mineral grains subjected to a variable temperature history was proposed. This model is applied to study the track annealing records in different meteorites resulting from their atmospheric heating. Scale lengths were measured of complete and partial track annealing, delta X sub 1 and delta X sub 2, respectively. In mineral grain close to fusion crust in about a dozen meteorites. Values of delta X sub 1 and delta X sub 2 depend on extent and duration of heating during atmospheric transit and hence on meteorite entry parameters. To estimate track annealing, the temperature history during atmospheric heating at different distances from the crusted surface of the meteorite is obtained by solving heat conduction equation in conjunction with meteorite entry model, and use of the annealing model to evaluate the degree of annealing of tracks. It is shown that the measured values of delta X sub 1 and delta X sub 2 in three of the meteorites studied are consistent with values using preatmospheric mass, entry velocity and entry angle of these meteorites.

  4. Laboratory studies of sources of HONO in polluted urban atmospheres

    NASA Astrophysics Data System (ADS)

    Saliba, Najat A.; Mochida, Michihiro; Finlayson-Pitts, Barbara. J.

    2000-10-01

    Laboratory studies reported here and in previous work show that the reaction of NO(g) with surface adsorbed HNO3 may be a significant source of HONO in polluted urban atmospheres. If these laboratory studies can be extrapolated to ambient conditions, this heterogeneous reaction may generate HONO to about the same extent as the hydrolysis of NO2 on surfaces, which is greater than the heterogeneous reaction of NO, NO2 and water. It may also be involved in generating HONO in snowpacks, and important in reconciling the discrepancy between measured and modeled HNO3/NOx ratios in the troposphere.

  5. Study of atmospheric pollution scavenging. Twenty-fourth progress report

    SciTech Connect

    Williams, A.L.

    1990-08-01

    Atmospheric scavenging research conducted by the Illinois State Water Survey under contract with the Department of Energy has been a significant factor in the historical development of the field of precipitation scavenging. Emphasis of the work during the 1980`s became focused on the problem of acid rain problem with the Survey being chosen as the Central Analytical Laboratory for sample analysis of the National Atmospheric Deposition Program National Trends Network (NADP/NTN). The DOE research was responsible for laying the groundwork from the standpoint of sampling and chemical analysis that has now become routine features of NADP/NTN. A significant aspect of the research has been the participation by the Water Survey in the MAP3S precipitation sampling network which is totally supported by DOE, is the longest continuous precipitation sampling network in existence, and maintains an event sampling protocol. The following review consists of a short description of each of the papers appearing in the Study of Atmospheric Scavenging progress reports starting with the Eighteenth Progress Report in 1980 to the Twenty- Third Progress Report in 1989. In addition a listing of the significant publications and interviews associated with the program are given in the bibliography.

  6. [Comprehensive study of lead pollution in atmospheric aerosol of Shanghai].

    PubMed

    Zhang, Gui-lin; Tan, Ming-guang; Li, Xiao-lin; Zhang, Yuan-xun; Yue, Wei-sheng; Chen, Jian-min; Wang, Yin-song; Li, Ai-guo; Li, Yan; Zhang, Yuan-mao; Shan, Zhu-ci

    2006-05-01

    The lead contamination, lead species and source assignment were studied by a combination of several analytical techniques such as Proton-induced X-ray emission analysis (PIXE), Proton microprobe (micro-PIXE), Inductively coupled plasma-mass spectrometry (ICP-MS) and extended X-ray absorption fine structure (EXAFS) techniques. The results indicate that the lead concentration in the air of Shanghai gradually decreased over the last years. The atmospheric lead concentration of PM10 in the winter of 2002 was 369 ng x m(-3), which had declined by 28% in 2001, and in the winter of 2003 it decreased further to 237 ng x m(-3). The main lead species in the samples collected in the winter of 2003 were probably PbCl2, PbSO4 and PbO. The source apportionment was calculated in terms of the combination of lead isotope ratios and lead mass balance method, assisted by single particle analysis with micro-PIXE and pattern recognition. The results suggest that the major contributors of atmospheric lead pollution in Shanghai are the coal combustion dust; the metallurgic dust and vehicle exhaust particles, with a contribution around 50%, 35% and 15%, respectively. It probably is the first time to give a city a quantitative estimation of lead pollution contribution from emission sources. The influence from leaded gasoline was still present in the atmosphere by four or five years after the phasing out of leaded gasoline. PMID:16850817

  7. VOCALS: The VAMOS Ocean-Cloud-Atmosphere-Land Study

    DOE Data Explorer

    Wood, Robert [VOCALS-REx PI, University of Washington; Bretherton, Christopher [GEWEX/GCSS Representative, University of Washington; Huebert, Barry [SOLAS Representative, University of Hawaii; Mechoso, Roberto C. [VOCALS Science Working Group Chair, UCLA; Weller, Robert [Woods Hole Oceanographic Institution

    VOCALS (VAMOS* Ocean-Cloud-Atmosphere-Land Study) is an international CLIVAR program the major goal of which is to develop and promote scientific activities leading to improved understanding of the Southeast Pacific (SEP) coupled ocean-atmosphere-land system on diurnal to inter-annual timescales. The principal program objectives are: 1) the improved understanding and regional/global model representation of aerosol indirect effects over the SEP; 2) the elimination of systematic errors in the region of coupled atmospheric-ocean general circulation models, and improved model simulations and predictions of the coupled climate in the SEP and global impacts of the system variability. VOCALS is organized into two tightly coordinated components: 1) a Regional Experiment (VOCALSREx), and 2) a Modeling Program (VOCALS-Mod). Extended observations (e.g. IMET buoy, satellites, EPIC/PACS cruises) will provide important additional contextual datasets that help to link the field and the modeling components. The coordination through VOCALS of observational and modeling efforts (Fig. 3) will accelerate the rate at which field data can be used to improve simulations and predictions of the tropical climate variability [Copied from the Vocals Program Summary of June 2007, available as a link from the VOCALS web at http://www.eol.ucar.edu/projects/vocals/]. The CLIVAR sponsored program to under which VOCALS falls is VAMOS, which stands for Variability of the American Monsoon Systems.

  8. Field and data analysis studies related to the atmospheric environment

    NASA Technical Reports Server (NTRS)

    Kidder, Stanley; Mach, Douglas; Bailey, Jeff; Stewart, Michael; Slaton, Dave; Buechler, Dennis; Botts, Michael; Collins, Laurie

    1994-01-01

    This report summarizes work on a broad array of projects including: (1) applications of meteorological and/or oceanographic satellites; (2) improvement of the current set of NASA/USAF lightning related launch commit criteria rules; (3) the design, building, testing and deployment of a set of cylindrical field mills for aircraft use; (4) the study of marginal electrification storm conditions in relationship to the current launch commit rules for the space shuttle and various other launch vehicles using an instrumented aircraft; (5) support of the DC-8 and ER-2 lightning instrument package as part of both the Tropical Ocean - Global Atmospheric/Coupled Ocean-Atmospheric Response Experiment and the Convection and Moisture Experiment; (6) design of electronic circuitry and microprocessor firmware for the NASA Advanced Ground Based Field Mill; (7) design and testing of electronic and computer instrumentation for atmospheric electricity measurements; (8) simulating observations from a lightning imaging sensor on the Tropical Rainfall Measuring satellite; and (9) supporting scientific visualization and the development of computer software tools.

  9. Atmospheric and surface compositional studies of Mercury and the moon

    NASA Technical Reports Server (NTRS)

    Potter, A. E.

    1988-01-01

    The atmosphere of the Moon and Mercury will be studied by means of high resolution spectroscopy of sodium and potassium resonance line emissions. The variation of metal vapor abundances with time, and with location will be measured with a view to understanding the origin and evolution of these elements in the atmospheres of the Moon and Mercury. Infrared spectroscopic measurements will be made of Mercury to determine the surface mineralogy, predicated on the availability of the Kuiper Airborne Observatory and infrared charge coupled device (CCD). During the past year, an excellent series of measurements were completed of the spatial distribution of sodium on Mercury. Sodium was found to be concentrated at the polar regions, and to be displaced towards the terminator by solar radiation pressure. Sodium and potassium were discovered in the atmosphere of the Moon. The ratio of sodium to potassium approximates that of the lunar regolith. Thermal infrared measurements of Mercury showed that the Christiansen peak was located shortwards of 8 micrometer, which indicates an acidic mineralogy.

  10. A study of the influence of forest gaps on fire-atmosphere interactions

    NASA Astrophysics Data System (ADS)

    Kiefer, Michael T.; Heilman, Warren E.; Zhong, Shiyuan; Charney, Joseph J.; Bian, Xindi

    2016-07-01

    Much uncertainty exists regarding the possible role that gaps in forest canopies play in modulating fire-atmosphere interactions in otherwise horizontally homogeneous forests. This study examines the influence of gaps in forest canopies on atmospheric perturbations induced by a low-intensity fire using the ARPS-CANOPY model, a version of the Advanced Regional Prediction System (ARPS) model with a canopy parameterization. A series of numerical experiments are conducted with a stationary low-intensity fire, represented in the model as a line of enhanced surface sensible heat flux. Experiments are conducted with and without forest gaps, and with gaps in different positions relative to the fire line. For each of the four cases considered, an additional simulation is performed without the fire to facilitate comparison of the fire-perturbed atmosphere and the background state. Analyses of both mean and instantaneous wind velocity, turbulent kinetic energy, air temperature, and turbulent mixing of heat are presented in order to examine the fire-perturbed atmosphere on multiple timescales. Results of the analyses indicate that the impact of the fire on the atmosphere is greatest in the case with the gap centered on the fire and weakest in the case with the gap upstream of the fire. It is shown that gaps in forest canopies have the potential to play a role in the vertical as well as horizontal transport of heat away from the fire. Results also suggest that, in order to understand how the fire will alter wind and turbulence in a heterogeneous forest, one needs to first understand how the forest heterogeneity itself influences the wind and turbulence fields without the fire.

  11. Recovering the Atmospheric Resources of Mars: Updating the MARRS Study

    NASA Astrophysics Data System (ADS)

    England, Christopher; Hrubes, J. Dana

    2006-01-01

    In 2000 a conceptual design was conducted of a plant that extracts oxygen (O2) directly from the martian atmosphere, and that makes water and carbon monoxide (CO) as by-products. Updated estimates suggest that the amount of O2 in the atmosphere is about 2.3 times greater than that used as the basis for the 2000 study. In this paper, estimates for O2 and by-products, and for energy and mass requirements based on the higher O2 value are updated. The basis for the design, termed ``MARRS'' for Mars Atmosphere Resource Recovery System, is the NASA/JSC Mars Reference Mission (MRM) requirement for O2, estimated at 5.8 kg/hr for about 500 sols. The 2000 study based its design on an atmospheric O2 content of 0.13%, the then-accepted value. Analysis now places the O2 content at about 0.3%, reducing the amount of energy and equipment proportionately. The revised estimate of the thermal power to meet MRM requirements for O2 is an average of about 52 kW, seasonally variable. The new mass estimate is 7898 kg, down from 13650 kg. The new estimate of oxygen content correspondingly reduces the amounts of by-products that can be recovered. CO, a primary fuel and propellant precursor, is produced at about 0.2 kg/kg O2. Water, possibly available at about 0.04 kg/kg O2, is believed not recoverable by the MARRS process at this lower level, even seasonally. An equation is provided for the seasonal variation in atmospheric O2 fraction based on Viking pressure measurements. Oxygen varies seasonally from about 0.25% or 0.34%, the variability affecting plant design. While the higher O2 fraction means reduced amounts of by-products from the MARRS process, large amounts of nitrogen (liquid and gas), argon gas and liquid carbon dioxide (CO2) remain available as by-products for use as respiratory agents, refrigerants, propellants, propellant precursors and working fluids for emergency or backup power, transportation, and surface operations such as drilling.

  12. [Research progress on case-control study].

    PubMed

    Zhang, F F; Liu, Z D; Zhang, C X; Jiang, B F

    2016-04-10

    Several new varients related to the case-control designs have been developed in the recent decades, and this article briefly summarized four new designs: two-stage design, case-specular study, exposure-crossover study and case-case-time-control study. This paper involved principles of study design, requisites for application, advantages and disadvantages on all the studies. PMID:27087230

  13. Model atmospheres and radiation of magnetic neutron stars. I - The fully ionized case

    NASA Technical Reports Server (NTRS)

    Shibanov, Iu. A.; Zavlin, V. E.; Pavlov, G. G.; Ventura, J.

    1992-01-01

    Model neutron star atmospheres are calculated for typical cooling stars with a strong magnetic field and effective temperatures of 10 exp 5 to 10 exp 6 K. The effect of anisotropic photon diffusion in two normal modes are examined under the assumption that the opacity is due solely to the bremsstrahlung and Thomson scattering processes under conditions of LTE that are expected to prevail at the temperatures and densities obtained. The main aspects of anisotropic photon diffusion, and an original procedure for calculating model atmospheres and emitted spectra are discussed. Representative calculated spectra are given, and it is found that the hard spectral excess characterizing the nonmagnetic case, while still present, becomes less prominent in the presence of magnetic fields in the range of 10 exp 11 to 10 exp 13 G.

  14. Designing case-control studies.

    PubMed Central

    Yanagawa, T

    1979-01-01

    Identification of confounding factors, evaluation of their influence on cause-effect associations, and the introduction of appropriate ways to account for these factors are important considerations in designing case-control studies. This paper presents designs useful for these purposes, after first providing a statistical definition of a confounding factor. Differences in the ability to identify and evaluate confounding factors and estimate disease risk between designs employing stratification (matching) and designs randomly sampling cases and controls are noted. Linear logistic models for the analysis of data from such designs are described and are shown to liberalize design requirements and to increase relative risk estimation efficiency. The methods are applied to data from a multiple factor investigation of lung cancer patients and controls. PMID:540588

  15. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2004-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.

  16. Studies on possible propagation of microbial contamination in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Dimmick, R. L.; Wolochow, H.; Chatigny, M. A.

    1975-01-01

    Maintained aerosols were studied to demonstrate the metabolism and propagation of microbes in clouds which could occur in the course of a probe of a planetary atmosphere. Bacteriophage was used as a tool to test whether the mechanisms for DNA production remain intact and functional within the airborne bacterial cell. In one test method, bacteria were mixed with coliphage in an atomizer to allow attachment before aerosolization; in another, two suspensions were atomized saperately into a common air stream prior to aerosolization. Results show that biochemical and physiological mechanisms to allow aerobic microbes to propagate in the airborne state do exist.

  17. Interaction of a jet with a radiation pressure-dominated atmosphere - The case of SS 433

    NASA Technical Reports Server (NTRS)

    Arav, Nahum; Begelman, Mitchell C.

    1993-01-01

    A phenomenological model for the enigmatic object SS 433 is developed in which SS 433 is a neutron star (NS) surrounded by a dense accreted atmosphere. Jets are created close to the neutron star surface by the rapidly spinning NS, toward which matter flows at a super-Eddington rate. This supercritical accretion leads to a quasi-spherical atmosphere around the NS with very high pressure and density close to the surface. The interaction of the jet with the atmosphere as it propagates through it is discussed in detail. A boundary layer (BL) due to radiation viscosity forms between the jet and the surrounding medium. This BL can be visualized as a cocoon of low-density matter around the jet which prevents mass entrainment into the jet. A study of X-ray spectra shows how the radiation-viscous BL can explain the very small Delta v/v that is observed in the jets.

  18. A case study of atmospheric boundary layer features during winter over a tropical inland station — Kharagpur (22.32°N, 87.32°E)

    NASA Astrophysics Data System (ADS)

    Alappattu, Denny P.; Kunhikrishnan, P. K.; Aloysius, Marina; Mohan, M.

    2009-08-01

    The local weather and air quality over a region are greatly influenced by the atmospheric boundary layer (ABL) structure and dynamics. ABL characteristics were measured using a tethered balloon-sonde system over Kharagpur (22.32°N, 87.32°E, 40m above MSL), India, for the period 7 December 2004 to 30 December 2004, as a part of the Indian Space Research Organization-Geosphere Biosphere Program (ISRO-GBP) Aerosol Land Campaign II. High-resolution data of pressure, temperature, humidity, wind speed and wind direction were archived along with surface layer measurements using an automatic weather station. This paper presents the features of ABL, like ABL depth and nocturnal boundary layer (NBL) depth. The sea surface winds from Quikscat over the oceanic regions near the experiment site were analyzed along with the NCEP/NCAR reanalysis winds over Kharagpur to estimate the convergence of wind, moisture and vorticity to understand the observed variations in wind speed and relative humidity, and also the increased aerosol concentrations. The variation of ventilation coefficient ( V C), a factor determining the air pollution potential over a region, is also discussed in detail.

  19. Study of atmospheric aerosol processing using confocal Raman microspectroscopy

    NASA Astrophysics Data System (ADS)

    Laskina, O.; Grassian, V. H.

    2012-12-01

    Aerosols undergo aging and heterogeneous chemistry as they are transported through the atmosphere. This leads to changes in their properties and their effects on climate, biogeochemistry and human health. Chemical imaging of individual particles may be used to directly investigate the heterogeneity of composition within atmospheric aerosol particles. Single-particle Raman microspectroscopy is a powerful method for chemical imaging and non-destructive physico-chemical characterization of aerosol particles. In this study we investigate the effect of chemical processing on the distribution of chemical species in single particles of mineral dust aerosol using Raman spectral imaging. Raman mapping was used to show the distribution of humic substances and organic acids on some major components of mineral dust (quartz, clays and calcium carbonate). It was shown that humic materials form coating on the surface of particles, whereas interactions of calcium carbonate with organic acids (oxalic and acetic acids) lead to reactions that cause a heterogeneous distribution of components within the reacted particle. Additionally, in a newly designed flow system aerosol can be equilibrated at different relative humidities to study hygroscopicity and phase transitions within these particles. These types of studies are important as the distribution of species in a single particle determines its reactivity, water uptake, and optical properties and thus defines its impact on climate and environment.

  20. A case for case studies: exploring the use of case study design in community nursing research.

    PubMed

    Bergen, A; While, A

    2000-04-01

    The case study has become an accepted vehicle for conducting research in a variety of disciplines. However, the meaning behind the term is not always made explicit by researchers and this has given rise to a number of assumptions which are open to challenge, and to questions about the robustness of the method. This paper explores some of the issues arising from one particular definition of case study research, used in a study by Yin which examined the practice of case management in community nursing. Four main areas are discussed. First, defining 'case' is seen to pose questions about the relationship of the phenomenon to its context, the degree of researcher control over case definition, the limits to what may constitute a 'case' and what is meant by the term 'unit of analysis'. Second, the relevance of external validity to case study research is supported through the use of a number of tactics, in particular Yin's concept of replication logic, which involves generalizing to theory, rather than to empirical data. Third, the use of method triangulation (multiple methods of data collection) is advanced as a means of enhancing construct validity in research where data converge around a particular theory. Finally, the relationship of the case study to theory construction, through the prior development of 'propositions' is discussed. Each of these issues is applied to the design and conduct of a research study based closely on Yin's multiple case study framework. Thirteen 'cases' were selected of case management practice and data were collected through interviews and examination of literature and documentation, to explore the suitability of community nurses for the role. It is concluded that, given the appropriate subject matter, context and research aims, the case study method may be seen as a credible option in nursing research. PMID:10759989

  1. Studying urban land-atmospheric interactions by coupling an urban canopy model with a single column atmospheric models

    NASA Astrophysics Data System (ADS)

    Song, J.; Wang, Z.

    2013-12-01

    Studying urban land-atmospheric interactions by coupling an urban canopy model with a single column atmospheric models Jiyun Song and Zhi-Hua Wang School of Sustainable Engineering and the Built Environment, Arizona State University, PO Box 875306, Tempe, AZ 85287-5306 Landuse landcover changes in urban area will modify surface energy budgets, turbulent fluxes as well as dynamic and thermodynamic structures of the overlying atmospheric boundary layer (ABL). In order to study urban land-atmospheric interactions, we coupled a single column atmospheric model (SCM) to a cutting-edge single layer urban canopy model (SLUCM). Modification of surface parameters such as the fraction of vegetation and engineered pavements, thermal properties of building and pavement materials, and geometrical features of street canyon, etc. in SLUCM dictates the evolution of surface balance of energy, water and momentum. The land surface states then provide lower boundary conditions to the overlying atmosphere, which in turn modulates the modification of ABL structure as well as vertical profiles of temperature, humidity, wind speed and tracer gases. The coupled SLUCM-SCM model is tested against field measurements of surface layer fluxes as well as profiles of temperature and humidity in the mixed layer under convective conditions. After model test, SLUCM-SCM is used to simulate the effect of changing urban land surface conditions on the evolution of ABL structure and dynamics. Simulation results show that despite the prescribed atmospheric forcing, land surface states impose significant impact on the physics of the overlying vertical atmospheric layer. Overall, this numerical framework provides a useful standalone modeling tool to assess the impacts of urban land surface conditions on the local hydrometeorology through land-atmospheric interactions. It also has potentially far-reaching implications to urban ecohydrological services for cities under future expansion and climate challenges.

  2. Multi-elements atmospheric deposition study in Albania.

    PubMed

    Qarri, Flora; Lazo, Pranvera; Stafilov, Trajce; Frontasyeva, Marina; Harmens, Harry; Bekteshi, Lirim; Baceva, Katerina; Goryainova, Zoya

    2014-02-01

    For the first time, the moss biomonitoring technique and inductively coupled plasma-atomic emission spectrometric (ICP-AES) analytical technique were applied to study multi-element atmospheric deposition in Albania. Moss samples (Hypnum cupressiforme) were collected during the summer of 2011 and September-October 2010 from 62 sites, evenly distributed over the country. Sampling was performed in accordance with the LRTAP Convention-ICP Vegetation protocol and sampling strategy of the European Programme on Biomonitoring of Heavy Metal Atmospheric Deposition. ICP-AES analysis made it possible to determine concentrations of 19 elements including key toxic metals such as Pb, Cd, As, and Cu. Cluster and factor analysis with varimax rotation was applied to distinguish elements mainly of anthropogenic origin from those predominantly originating from natural sources. Geographical distribution maps of the elements over the sampled territory were constructed using GIS technology. The median values of the elements in moss samples of Albania were high for Al, Cr, Ni, Fe, and V and low for Cd, Cu, and Zn compared to other European countries, but generally were of a similar level as some of the neighboring countries such as Bulgaria, Croatia, Kosovo, Macedonia, and Romania. This study was conducted in the framework of ICP Vegetation in order to provide a reliable assessment of air quality throughout Albania and to produce information needed for better identification of contamination sources and improving the potential for assessing environmental and health risks in Albania, associated with toxic metals. PMID:24081920

  3. Studies of the atmospheric correction for satellite laser ranging

    NASA Astrophysics Data System (ADS)

    Angus-Leppan, P. V.; Williams, G.

    A study is reported on the factors necessary to achieve further gains in accuracy in laser ranging. The present accuracy of laser ranging is approaching plus or minus 50 mm, which indicates a need to aim for a plus or minus 5 mm accuracy in the determination of the correction for atmospheric refraction. The Marini and Murray formulae are easily programmed and are widely used. They assume hydrostatic equilibrium and a constant vertical temperature gradient in the troposphere. It appears that some refinements are necessary to achieve the accuracy required. The atmospheric correction varies from 2.4 m at the zenith to 13 m at 10 degrees elevation. A number of small effects such as the geometric correction, the water vapor correction, and horizontal temperature gradients are all about plus or minus 30 mm in magnitude. In the study reported, the integral of refractivity is evaluated using numerical methods. The effects of the varying temperature gradients in the lowest kilometer, the boundary layer, have been investigated and a form of boundary layer correction, up to plus or minus 25 mm in magnitude, is suggested. Investigations are continuing, using a theoretical approach and sets of temperature observations on high towers.

  4. A photochemical reactor for studies of atmospheric chemistry

    NASA Astrophysics Data System (ADS)

    Nilsson, E. J. K.; Eskebjerg, C.; Johnson, M. S.

    A photochemical reactor for studies of atmospheric kinetics and spectroscopy has been built at the Copenhagen Center for Atmospheric Research. The reactor consists of a vacuum FTIR spectrometer coupled to a 100 L quartz cylinder by multipass optics mounted on electropolished stainless steel end flanges, surrounded by UV-A, UV-C and broadband sun lamps in a temperature-controlled housing. The combination of a quartz vessel and UV-C lamps allows higher concentrations of O( 1D) and OH than can be generated by similar chambers. The reactor is able to produce radical concentrations of ca. 8 × 10 11 cm -3 for OH, 3 × 10 6 cm -3 for O( 1D), 3.3 × 10 10 cm -3 for O( 3P) and 1.6 × 10 12 cm -3 for Cl. The reactor can be operated at pressures from 10 -3 to 10 3 mbar and temperatures from 240 to 330 K. As a test of the system we have studied the reaction CHCl 3 + Cl using the relative rate technique and find k CHCl3+Cl/k CH4+Cl = 1.03 ± 0.11, in good agreement with the accepted value.

  5. Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study

    NASA Astrophysics Data System (ADS)

    Abkar, Mahdi; Porté-Agel, Fernando

    2014-05-01

    In this study, large-eddy simulation is combined with a turbine model to investigate the influence of atmospheric stability on wind-turbine wakes. In the simulations, subgrid-scale turbulent fluxes are parameterized using tuning-free Lagrangian scale-dependent dynamic models. These models optimize the local value of the model coefficients based on the dynamics of the resolved scales. The turbine-induced forces are parameterized with an actuator-disk model with rotation. In this technique, blade-element theory is used to calculate the lift and drag forces acting on the blades. Emphasis is placed on the structure and characteristics of wind-turbine wakes in the cases where the incident flows to the turbine have the same mean velocity at the hub height but different stability conditions. The simulation results show that atmospheric stability has a significant effect on the spatial distribution of the mean velocity deficit and turbulent fluxes in the wake region. In particular, the magnitude of the velocity deficit increases with increasing stability in the atmosphere. In addition, the locations of the maximum turbulence intensity and turbulent stresses are closer to the turbine in convective boundary layer compared with neutral and stable ones. Detailed analysis of the resolved turbulent kinetic energy (TKE) budget inside the wake reveals also that the thermal stratification of the incoming wind considerably affects the magnitude and spatial distribution of the turbulent production, transport term and dissipation rate (transfer of energy to the subgrid scales). It is also shown that the near-wake region can be extended to a farther distance downstream in stable condition compared with neutral and unstable counterparts. In order to isolate the effect of atmospheric stability, additional simulations of neutrally-stratified atmospheric boundary layers are performed with the same turbulence intensity at hub height as convective and stable ones. The results show that the

  6. Study of short atmospheric pressure dc glow microdischarge in air

    NASA Astrophysics Data System (ADS)

    Kudryavtsev, Anatoly; Bogdanov, Eugene; Chirtsov, Alexander; Emelin, Sergey

    2011-10-01

    The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen and oxygen atoms; ozone molecule; and different nitrogen and oxygen ions with different plasmochemical reactions between them. Simulations predicted the main regions of the dc glow discharges including cathode and anode sheath and plasma of negative glow, Faraday dark space and transition region. Gas heating plays an important role in shaping the discharge profiles. The results of experiments and simulations of short (without positive column) atmospheric pressure dc glow discharge in air are presented. We used metal steel electrodes with a gap of 5-100 microns. The experimental voltage-current characteristic's (VAC) have a constant or slightly increasing form at low gap. The most stable microdischarges were burning with a flat cathode and rounded anode, when the length of the discharge is automatically established near the minimum of the Paschen curve by changing their binding on the anode. In this case microdischarge was stable and it had growing VAC. For simulations we used 2D fluid model with kinetic description of electrons. We solved the balance equations for the vibrationally- and the electronically-excited states of a nitrogen and oxygen molecules; nitrogen

  7. Dynamic flood risk: case studies

    NASA Astrophysics Data System (ADS)

    Di Baldassarre, Giuliano

    2013-04-01

    While many progresses have been made in the static assessment of (current) flood risk, additional transdisciplinary research is required for the development of new methods for the dynamic assessment of (future) flood risk, which is very much needed in a rapidly changing environment. To this end, it is essential to understand why flood risk has changed in the past. This presentation shows the scientific outcomes of diverse case studies (the Po river in Italy and a number of African rivers), whereby data and models are utilized to analyse and interpret the dynamics of flood risk. In particular, a number of hypotheses were tested by considering different agents of change, such as climate and/or land-use, flood prevention measures, human population dynamics. These case studies show that one of the main challenges in assessing (dynamic) flood risk is the deep interconnection not only between the different agents of change, but also between the components of risk (i.e. hazard, exposure, vulnerability or resilience). For instance, changes in flood hazard often trigger changes in exposure and vulnerability to flooding, and vice versa. These complex interactions seem to make predictions of future flood risk over long time scales rather difficult, if not impossible.

  8. Experimental studies on atmospheric Stirling engine NAS-2

    SciTech Connect

    Watanabe, Hiroichi; Isshiki, Naotsugu; Ohtomo, Michihiro

    1996-12-31

    Atmospheric hot air Stirling engine NAS-1 and 2 have a simple flat rubber sheet diaphragm as their power piston, and they have been experimentally studied at Nihon University for several years continuously, with the target of to get more than 100 watts shaft power by atmospheric air with simple construction and cheap material. The first NAS-1 was intended to be a solar heated engine using television glass and wood for cheap cost, but it failed by thermal break of glass, so the improved NAS-2 is changed to be heated by gas burner, using metallic materials in all parts except rubber power piston. Other than this rubber sheet diaphragm, NAS-2 has many features as using James Watt crank mechanism, high finny copper tube for conventional commercial heat exchanger, and two kinds of hot gas heaters, etc. About the rubber sheet for the power piston, the thickness of the sheet was changed from 2 mm to 6 mm gradually to known what thickness is best, and it is found that about 5 mm is best for this engine. After trying many improvements on this engine, NAS-2 has produced about 130 watt shaft power with indicated power of 350 watt at 1994. In this paper detail of many features, history, results and experiments of these NAS engines are reported.

  9. Study of inlet materials for sampling atmospheric nitric acid

    SciTech Connect

    Neuman, J.A.; Huey, L.G.; Ryerson, T.B.; Fahey, D.W. |

    1999-04-01

    The adsorption of nitric acid (HNO{sub 3}) from a flowing gas stream is studied for a variety of wall materials to determine their suitability for use in atmospheric sampling instruments. Parts per billion level mixtures of HNO{sub 3} in synthetic air flow through tubes of different materials such that >80% of the molecules interact with the walls. A chemical ionization mass spectrometer with a fast time response and high sensitivity detects HNO{sub 3} that is not adsorbed on the tube walls. Less than 5% of available HNO{sub 3} is adsorbed on Teflon fluoropolymer tubing after 1 min of HNO{sub 3} exposure, whereas >70% is lost on walls made of stainless steel, glass, fused silica, aluminum, nylon, silica-steel, and silane-coated glass. Glass tubes exposed to HNO{sub 3} on the order of hours passivate with HNO{sub 3} adsorption dropping to zero. The adsorption of HNO{sub 3} on PFA Teflon tubing (PFA) is nearly temperature-independent from 10 to 80 C, but below {minus}10 C nearly all HNO{sub 3} that interacts with PFA is reversibly adsorbed. In ambient and synthetic air, humidity increases HNO{sub 3} adsorption. The results suggest that Teflon at temperatures above 10 C is an optimal choice for inlet surfaces used for in situ measurements of HNO{sub 3} in the ambient atmosphere.

  10. Electron Spectroscopy for Chemical Analysis (ESCA) study of atmospheric particles

    NASA Technical Reports Server (NTRS)

    Dillard, J. G.; Seals, R. D.; Wightman, J. P.

    1979-01-01

    The results of analyses by ESCA (Electron Spectroscopy for Chemical Analysis) on several Nuclepore filters which were exposed during air pollution studies are presented along with correlative measurements by Neutron Activation Analysis and Scanning Electron Microscopy. Samples were exposed during air pollution studies at Norfolk, Virginia and the NASA Kennedy Space Center (KSC). It was demonstrated that with the ESCA technique it was possible to identify the chemical (bonding) state of elements contained in the atmospheric particulate matter collected on Nuclepore filters. Sulfur, nitrogen, mercury, chlorine, alkali, and alkaline earth metal species were identified in the Norfolk samples. ESCA binding energy data for aluminum indicated that three chemically different types of aluminum are present in the launch and background samples from NASA-KSC.

  11. Multiple stable oxygen isotopic studies of atmospheric sulfate: A new quantitative way to understand sulfate formation processes in the atmosphere

    NASA Astrophysics Data System (ADS)

    Lee, Charles Chi-Woo

    2000-11-01

    Sulfate is an important trace species in the Earth's atmosphere because of its roles in numerous atmospheric processes. In addition to its inherent light-scattering properties, sulfate can serve as cloud condensation nucleus (CCN), affecting cloud formation as well as microphysical properties of clouds. Consequently, atmospheric sulfate species influence the global radiative energy balance. Sulfate is known to increase acidity of rainwater with negative consequences in both natural and urban environments. In addition, aerosol sulfate (<=2.5 μm) is respirable and poses a threat to human health as a potential carrier of toxic pollutants through the respiratory tract. Despite intense investigative effort, uncertainty regarding the relative significance of gas and aqueous phase oxidation pathways still remains. Acquisition of such information is important because the lifetime and transport of S(IV) species and sulfate aerosols are influenced by the oxidative pathways. In addition, sulfate formation processes affect the aerosol size distribution, which ultimately influences radiative properties of atmospheric aerosols. Therefore, the budgetary information of the sulfur cycle, as well as the radiative effects of sulfate on global climate variation, can be attained from better quantitative understanding of in situ sulfate formation processes in the atmosphere. Multiple stable oxygen isotopic studies of atmospheric sulfate are presented as a new tool to better comprehend the atmospheric sulfate formation processes. Coupled with isotopic studies, 35S radioactivity measurements have been utilized to assess contribution of sulfate from high altitude air masses. Atmospheric sulfate (aerosols and rainwater) samples have been collected from diverse environments. Laboratory experiments of gas and aqueous phase S(IV) oxidation by various oxidants, as well as biomass burning experiments, have also been conducted. The main isotopic results from these studies are as follows: (1

  12. A Study on Atmospheric Corrosion of 304 Stainless Steel in a Simulated Marine Atmosphere

    NASA Astrophysics Data System (ADS)

    Lv, Wangyan; Pan, Chen; Su, Wei; Wang, Zhenyao; Liu, Shinian; Wang, Chuan

    2015-07-01

    The atmospheric corrosion behavior of 304 stainless steel in a simulated marine atmosphere has been investigated using scanning electron microscope, optical microscope, x-ray photoelectron spectroscopy (XPS), and electrochemical measurements. The experimental results indicate that the main corrosion type of 304 stainless steel in a simulated marine atmosphere is pitting corrosion and the initiation of pits is associated with the dissolution of MnS inclusion. The maximum pit depth of 304 stainless steel increased in linear relationship with the extension of corrosion time. XPS results reveal that the corrosion products possess more hydroxide, and the ratio of [Cr]/{[Cr]+[Fe]} in the corrosion products gradually increases with the increasing time. The protective ability of corrosion products formed on 304 stainless steel has also been discussed.

  13. The Colorado Center for Lunar Dust and Atmospheric Studies

    NASA Astrophysics Data System (ADS)

    Collette, A.; Gruen, E.; Horanyi, M.; Munsat, T.; Poppe, A. R.; Robertson, S. H.; Srama, R.; Shu, A. J.; Sternovsky, Z.; Wang, X.; Ccldas Team

    2010-12-01

    The Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) is a member of the NASA Lunar Science Institute, focused on experimental and theoretical investigations of the lunar surface, including dusty plasma and impact processes, the origins of the lunar atmosphere, and the development of new instrument concepts, with a complementary program of education and community development. The tenuous lunar atmosphere is a surface-bound exosphere (SBE) similar to that found throughout the solar system, for example on Mercury, various icy satellites, over the rings of Saturn, on large asteroids, and on Kuiper Belt objects. Its time-dependent constituents arise from a dynamic balance between sources that may be sporadic (solar wind, sputtering, micrometeoroid impacts, outgassing) and loss mechanisms (escape, ionization), creating a natural dusty plasma laboratory. CCLDAS supports a diverse experimental program, performed in conjunction with theory and simulation, to investigate the near-surface lunar plasma environment, dust charging and mobilization, and the effects of micrometeoroids. The flagship device at CCLDAS is a dust accelerator, currently under construction, which will allow simulation of micrometeoroid impacts at speeds relevant to the lunar environment. The accelerator will be available for direct science investigation as well as instrument calibration; in addition to our own research program, the experimental facilities are open to the lunar and space physics community. One use will be to support the calibration of the Lunar Dust EXperiment (LDEX) instrument, scheduled for launch in 2013 onboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft. LDEX will measure the density and temporal variation of micron and submicron sized dust particles released from the lunar surface and elevated to > 30 km altitude by micrometeoroid bombardment and/or electrostatic forces. The new Lunar Environment and Impact Laboratory (LEIL) at CCLDAS

  14. Parameter Study of Plasma-Induced Atmospheric Sputtering and Heating at Mars

    NASA Astrophysics Data System (ADS)

    Williamson, Hayley N.; Johnson, Robert E.; Leblanc, Francois

    2014-11-01

    Atoms and molecules in Mars’ upper atmosphere are lost predominately through sputtering, caused by the impact of ions into the exosphere, dissociative recombination, and thermal escape. While all three processes are thought to occur on Mars, a detailed understanding must ascertain the relative importance of each process, due to time variations in pick-up and solar wind ions. In this project, using case studies of an oxygen atmosphere modeled with Direct Simulation Monte Carlo techniques, we have endeavored to categorize when the momentum transfer or thermal escape is more likely to occur. To do this, we vary the incident plasma flux and energy based on models of the interaction of the solar wind with the Martian atmosphere. We first repeat the heating and sputtering rates due to a flux of pick-up O+ examined previously (Johnson et al. 2000; Michael and Johnson 2005; Johnson et al 2013). We have used multiple examples of particle fluxes for various solar wind conditions, from steady solar wind conditions (Luhmann et al. 1992; Chaufray et al. 2007) to more extreme cases (Fang et al. 2013; Wang et al. 2014), which are thought to increase escape by several orders of magnitude. The goal is to explore the escape parameter space in preparation for the expected data from MAVEN on hot atoms and molecules in the Martian exosphere.

  15. Comprehensive NO-dependent study of the products of the oxidation of atmospherically relevant aromatic compounds.

    PubMed

    Birdsall, Adam W; Elrod, Matthew J

    2011-06-01

    A comprehensive product study, performed via the turbulent flow chemical ionization mass spectrometry (TF-CIMS) technique, of the primary OH-initiated oxidation of many of the atmospherically abundant aromatic compounds was performed. The bicyclic peroxy radical intermediate, a key proposed intermediate species in the Master Chemical Mechanism (MCM) for the atmospheric oxidation of aromatics, was detected in all cases, as were stable bicyclic species. The NO product yield dependences suggest a potential role for bicyclic peroxy radical + HO(2) reactions at high HO(2)/NO ratios, which are postulated to be a possible source of the inconsistencies between previous environmental chamber results and predictions from the MCM for ozone production and OH reactivity. The TF-CIMS product yield results are also compared to previous environment chamber results and to the latest MCM parametrization. PMID:21553858

  16. First-principles study of the stability of free-standing germanene in oxygen atmosphere

    SciTech Connect

    Liu, G.; Liu, S. B. Song, H. Y.; Xu, B.; Ouyang, C. Y.

    2015-09-28

    The O{sub 2} dissociation and O atoms adsorption on free-standing germanene are studied by using first-principles calculations in this paper. Compared with the extremely active silicene in oxygen atmosphere, germanene is found to be less active due to an energy barrier for dissociation of about 0.57 eV. Moreover, the dissociated oxygen atom follows two opposite migration pathways on the germanene surface, which is quite different from the case of silicene. Furthermore, the migration and desorption of O atoms at room temperature are relatively difficult due to the strong Ge-O bonding, resulting in the formation of germanium oxides. Our results reveal the interplay between germanene and O{sub 2} and suggest the enhanced stability of germanene in oxygen atmosphere compared with silicene.

  17. First-principles study of the stability of free-standing germanene in oxygen atmosphere

    NASA Astrophysics Data System (ADS)

    Liu, G.; Liu, S. B.; Xu, B.; Ouyang, C. Y.; Song, H. Y.

    2015-09-01

    The O2 dissociation and O atoms adsorption on free-standing germanene are studied by using first-principles calculations in this paper. Compared with the extremely active silicene in oxygen atmosphere, germanene is found to be less active due to an energy barrier for dissociation of about 0.57 eV. Moreover, the dissociated oxygen atom follows two opposite migration pathways on the germanene surface, which is quite different from the case of silicene. Furthermore, the migration and desorption of O atoms at room temperature are relatively difficult due to the strong Ge-O bonding, resulting in the formation of germanium oxides. Our results reveal the interplay between germanene and O2 and suggest the enhanced stability of germanene in oxygen atmosphere compared with silicene.

  18. Case Study: A Picture Worth a Thousand Words? Making a Case for Video Case Studies

    ERIC Educational Resources Information Center

    Pai, Aditi

    2014-01-01

    A picture, they say, is worth a thousand words. If a mere picture is worth a thousand words, how much more are "moving pictures" or videos worth? The author poses this not merely as a rhetorical question, but because she wishes to make a case for using videos in the traditional case study method. She recommends four main approaches of…

  19. The CZSaw notes case study

    NASA Astrophysics Data System (ADS)

    Lee, Eric; Gupta, Ankit; Darvill, David; Dill, John; Shaw, Chris D.; Woodbury, Robert

    2013-12-01

    Analysts need to keep track of their analytic findings, observations, ideas, and hypotheses throughout the analysis process. While some visual analytics tools support such note-taking needs, these notes are often represented as objects separate from the data and in a workspace separate from the data visualizations. Representing notes the same way as the data and integrating them with data visualizations can enable analysts to build a more cohesive picture of the analytical process. We created a note-taking functionality called CZNotes within the visual analytics tool CZSaw for analyzing unstructured text documents. CZNotes are designed to use the same model as the data and can thus be visualized in CZSaw's existing data views. We conducted a preliminary case study to observe the use of CZNotes and observed that CZNotes has the potential to support progressive analysis, to act as a shortcut to the data, and supports creation of new data relationships.

  20. STS Case Study Development Support

    NASA Technical Reports Server (NTRS)

    Rosa de Jesus, Dan A.; Johnson, Grace K.

    2013-01-01

    The Shuttle Case Study Collection (SCSC) has been developed using lessons learned documented by NASA engineers, analysts, and contractors. The SCSC provides educators with a new tool to teach real-world engineering processes with the goal of providing unique educational materials that enhance critical thinking, decision-making and problem-solving skills. During this third phase of the project, responsibilities included: the revision of the Hyper Text Markup Language (HTML) source code to ensure all pages follow World Wide Web Consortium (W3C) standards, and the addition and edition of website content, including text, documents, and images. Basic HTML knowledge was required, as was basic knowledge of photo editing software, and training to learn how to use NASA's Content Management System for website design. The outcome of this project was its release to the public.

  1. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2003-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HC1 vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow- chemical ionization mass spectrometry and optical ellipsometry, among others. The next section summarizes our research activities during the first year of the project, and the section that follows consists of the statement of work for the second year.

  2. Theoretical studies of important processes in planetary and comet atmospheres

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1991-01-01

    The dissociative recombination (DR) of the AB(+) molecular ion with an electron has been shown to be an important component in the detailed interpretation of planetary ionosphere data. A first principles theoretical approach is developed for calculating the DR cross sections and rates for AB(+) molecular ions. The calculations focus on O2(+) and N2(+) DR, and are the first to include the indirect DR mechanism (Ryberg vibrational levels below v = 0 level of ion) for a molecule larger than H2(+). The importance of electron capture width in calculating the cross sections and rates is also examined. Electron capture widths are given for all states of O2 that are of importance to DR (lowest 10 vibrational levels of ion). Knowledge of the details of dissociative recombination will be needed for interpretation of data from future interplanetary and comet atmospheric studies.

  3. Studies of atmospheric aerosols in Mexico City using PIXE

    NASA Astrophysics Data System (ADS)

    Miranda, J.; Crespo, I.; González, S.; López-Suárez, A.; Morales, M. A.; Pablo, B.; Paredes-Gutiérrez, R.

    1997-02-01

    Along the years 1993-1995 several studies of atmospheric aerosols in the Metropolitan Area of Mexico City were performed. Typically, samples were collected in morning periods (8:00 h to 14:00 h) following different protocols, using a Stacking Filter Unit of the Davis design, separating particles with sizes between 2.5 μm and 15 μm (known as coarse fraction, deposited on polycarbonate filters) and smaller than 2.5 μm (known as fine fraction, collected on Teflon or polycarbonate filters). Elemental analysis of the particulate matter deposited onto the filters was done with Proton Induced X-ray Emission (PIXE). A summary of the results for the fine fraction is presented, including mean elemental concentrations, and results of multivariate statistical analyses, such as Cluster Analysis and Principal Component Analysis. The influence of meteorological parameters to the local elemental concentrations is discussed on the basis of multivariate statistics.

  4. An overview of the Soviet Vega balloon experiment and studies of the atmosphere of Venus

    NASA Technical Reports Server (NTRS)

    Sagdeev, R. Z.

    1986-01-01

    An overview of the VEGA probe to Venus is given, including a detailed examination of the balloon experiment to study the atmosphere of Venus. The areas of study include the ground network, the global network of radiotelescopes, meteorological measurements, the thermal structure of the Venus atmosphere in the middle cloud layer, atmospheric dynamics, and other results of the VEGA 1 and 2 experiments.

  5. Atmospheric lidar multi-user instrument system definition study

    NASA Technical Reports Server (NTRS)

    Greco, R. V. (Editor)

    1980-01-01

    A spaceborne lidar system for atmospheric studies was defined. The primary input was the Science Objectives Experiment Description and Evolutionary Flow Document. The first task of the study was to perform an experiment evolutionary analysis of the SEED. The second task was the system definition effort of the instrument system. The third task was the generation of a program plan for the hardware phase. The fourth task was the supporting studies which included a Shuttle deficiency analysis, a preliminary safety hazard analysis, the identification of long lead items, and development studies required. As a result of the study an evolutionary Lidar Multi-User Instrument System (MUIS) was defined. The MUIS occupies a full Spacelab pallet and has a weight of 1300 kg. The Lidar MUIS laser provides a 2 joule frequency doubled Nd:YAG laser that can also pump a tuneable dye laser wide frequency range and bandwidth. The MUIS includes a 1.25 meter diameter aperture Cassegrain receiver, with a moveable secondary mirror to provide precise alignment with the laser. The receiver can transmit the return signal to three single and multiple photomultiple tube detectors by use of a rotating fold mirror. It is concluded that the Lidar MUIS proceed to program implementation.

  6. Using Case Studies To Teach Science.

    ERIC Educational Resources Information Center

    Gabel, Connie

    Using case studies in science instruction develops problem solving and enhances listening and cooperative learning skills. Unlike other disciplines such as law and medicine, the case study method is rarely used in science education to enrich the curriculum. This study investigates the use of content-based case studies as a means of developing…

  7. Assessment of AERMOD offline Integration with WRF-ARW Mesoscale Atmospheric model by predicting ground level concentrations of oxides of nitrogen due to area and point sources over an urban area: A case study

    NASA Astrophysics Data System (ADS)

    Boadh, Rahul; Satyanarayana A. N., V.; Ramakrishna T. V. B. P., S.; Madala, Srikanth

    2015-04-01

    The deterioration of air quality may be attributed to the rapid industrialization, consequent urbanization and increased growth of vehicular traffic. In urban areas, the day to day increase in vehicular traffic has provided the impetus for comprehensive monitoring/modeling of air quality. In the present study, vehicular traffic as area sources and power plant as point source, the two major sources of oxides of nitrogen (NOX), was has considered. Gaussian plume air dispersion model, AERMOD is used for assessment of NOX dispersion over Nagpur city, Maharashtra. The processes within the planetary boundary layer (PBL) play an important role in the dispersion of air pollutants. AERMOD requires surface and upper air meteorological observations and various PBL parameters with good temporal resolution in the stand alone mode and mostly the data on PBL parameters is not available routinely over India. In the present study, an attempt has been made to simulate the necessary boundary layer parameters from WRF-ARW model and then offline coupled with AERMOD dispersion model. High resolution simulations with triple nested domain (horizontal resolution of 27, 9 and 3 km; 27 vertical levels) are carried out with WRF-ARW model. The surface and upper air meteorological data along with the computed PBL parameters of winter and pre-monsoon seasons representing January and April respectively in the year 2009 are considered for dispersion of the NOX over Nagpur. Experiments are conducted with two best PBL parameterization schemes over study region, non-local Yonsei University (YSU) and local Mellor-Yamada-Janjic (MYJ) schemes. AERMOD with 1 km resolution has been used for predicting the concentrations of NOX over Nagpur city. NOX observations from six monitoring stations of Central Pollution Control Board are used for validation of model predicted concentrations. The NOX concentrations are found to have over-predicted in both seasons. Close examination of the computed statistical errors

  8. a Study of the Origin of Atmospheric Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Hildemann, Lynn Mary

    1990-01-01

    The sources of ambient organic particulate matter in urban areas are investigated through a program of emission source measurements, atmospheric measurements, and mathematical modeling of source/receptor relationships. A dilution sampler intended to collect fine organic aerosol from combustion sources is designed to simulate atmospheric cooling and dilution processes, so that organic vapors which condense under ambient conditions will be collected as particulate matter. This system is used to measure the emissions from a boiler burning distillate oil, a home fireplace, catalyst and noncatalyst automobiles, heavy-duty diesel trucks, natural gas home appliances, and meat cooking operations. Alternate techniques are used to sample the particulate matter emitted from cigarette smoking, a roofing tar pot, paved road dust, brake lining wear, tire wear, and vegetative detritus. The bulk chemical characteristics of the fine aerosol fraction are presented for each source. Over half of the fine aerosol mass emitted from automobiles, wood burning, meat cooking, home appliances, cigarettes, and tar pots is shown to consist of organic compounds. The organic material collected from these sources is analyzed using high-resolution gas chromatography. Using a simple analytical protocol, a quantitative, 50-parameter characterization of the elutable fine organic aerosol emitted from each source type is obtained, which proves to be a unique fingerprint that can be used to distinguish most sources from each other. A mathematical model is used to predict the characteristics of fine ambient organic aerosol in the Los Angeles area that would prevail if the primary organic emissions are transported without chemical reaction. The model is found to track the seasonal variations observed in the ambient aerosol at the three sites studied. Emissions from vehicles and fireplaces are identified as significant sources of solvent-extractable organic aerosol. Differences between the model

  9. Case studies of selected Project "Flash" events

    NASA Astrophysics Data System (ADS)

    Nicolaides, K. A.; Michaelides, S. C.; Savvidou, K.; Orphanou, A.; Constantinides, P.; Charalambous, M.; Michaelides, M.

    2009-03-01

    Flooding is a consequence of the prevailing meteorological situation, the intensity and duration of precipitation, geomorphology, human activities over a geographical region and other factors. Floods result in damage and destruction of infrastructure and private property and, in some cases, in fatalities. Flash floods are sudden and quite localized in extend, characterized by excessive amounts of rainfall within a short period of time and are distinguished from other floods by their degree of severity. The broader knowledge concerning flash floods is useful for the better understanding of the underlying thermodynamic and dynamic mechanisms, as well as the associated physical processes. The wider understanding of flashfloods can form part of an integrated system for short and very short forecasting of these events. In the present study, the synoptic, dynamic and thermodynamic conditions during the development of a baroclinic depression which affected the area of Cyprus on 6 November 2005 are studied. The depression was associated with extreme weather phenomena, such as thunderstorms, a water spout and high precipitation accumulations. The results indicate the importance of the dynamic parameters in the system's development and the thermodynamic analysis has shown the convective potential of the atmosphere.

  10. Assessing Polycyclic Aromatic Hydrocarbons (PAHs) using passive air sampling in the atmosphere of one of the most wood-smoke-polluted cities in Chile: The case study of Temuco.

    PubMed

    Pozo, Karla; Estellano, Victor H; Harner, Tom; Diaz-Robles, Luis; Cereceda-Balic, Francisco; Etcharren, Pablo; Pozo, Katerine; Vidal, Victor; Guerrero, Fabián; Vergara-Fernández, Alberto

    2015-09-01

    This study addresses human health concerns in the city of Temuco that are attributed to wood smoke and related pollutants associated with wood burning activities that are prevalent in Temuco. Polycyclic Aromatic Hydrocarbons (PAHs) were measured in air across urban and rural sites over three seasons in Temuco using polyurethane foam (PUF) disk passive air samplers (PUF-PAS). Concentrations of ΣPAHs (15 congeners) in air ranged from BDL to ∼70 ng m(-3) and were highest during the winter season, which is attributed to emissions from residential heating by wood combustion. The results for all three seasons showed that the PAH plume was widespread across all sites including rural sites on the outskirts of Temuco. Some interesting variations were observed between seasons in the composition of PAHs, which were attributed to differences in seasonal point sources. A comparison of the PAH composition in the passive samples with active samples (gas+particle phase) from the same site revealed similar congener profiles. Overall, the study demonstrated that the PUF disk passive air sampler provides a simple approach for measuring PAHs in air and for tracking effectiveness of pollution control measures in urban areas in order to improve public health. PMID:26022137

  11. Numerical Modeling Studies of Wake Vortices: Real Case Simulations

    NASA Technical Reports Server (NTRS)

    Shen, Shao-Hua; Ding, Feng; Han, Jongil; Lin, Yuh-Lang; Arya, S. Pal; Proctor, Fred H.

    1999-01-01

    A three-dimensional large-eddy simulation model, TASS, is used to simulate the behavior of aircraft wake vortices in a real atmosphere. The purpose for this study is to validate the use of TASS for simulating the decay and transport of wake vortices. Three simulations are performed and the results are compared with the observed data from the 1994-1995 Memphis field experiments. The selected cases have an atmospheric environment of weak turbulence and stable stratification. The model simulations are initialized with appropriate meteorological conditions and a post roll-up vortex system. The behavior of wake vortices as they descend within the atmospheric boundary layer and interact with the ground is discussed.

  12. A study of the origin of atmospheric organic aerosols

    SciTech Connect

    Hildemann, L.M.

    1990-01-01

    The sources of ambient organic particulate matter in urban areas are investigated through a program of emission source measurements, atmospheric measurements, and mathematical modeling of source/receptor relationships. A dilution sampler intended to collect fine organic aerosol from combustion sources is designed to simulate atmospheric cooling and dilution processes, so that organic vapors which condense under ambient conditions will be collected as particulate matter. This system is used to measure the emissions from a boiler burning distillate oil, a home fireplace, catalyst and noncatalyst automobiles, heavy-duty diesel trucks, natural gas home appliances, and meat-cooking operations. Alternate techniques are used to sample the particulate matter emitted from cigarette smoking, a roofing tar pot, paved road dust, brake lining wear, tire wear, and vegetative detritus. The bulk chemical characteristics of the fine aerosol fraction are presented for each source. Over half of the fine aerosol mass emitted from automobiles, wood burning, meat cooking, home appliances, cigarettes, and tar pots is shown to consist of organic compounds. The organic material collected from these sources is analyzed using high-resolution gas chromatography. Using a simple analytical protocol, a quantitative, 50-parameter characterization of the elutable fine organic aerosol emitted from each source type is obtained, which proves to be a unique fingerprint that can be used to distinguish most sources from each other. A mathematical model is used to predict the characteristics of fine ambient organic aerosol in the Los Angeles area that would prevail if the primary organic emissions are transported without chemical reaction. The model is found to track the seasonal variations observed in the ambient aerosol at the three sites studied.

  13. [Study on atmospheric VOCs in Gongga Mountain base station].

    PubMed

    Zhang, Jun-Ke; Wang, Yue-Si; Wu, Fang-Kun; Sun, Jie

    2012-12-01

    Volatile organic compounds (VOCs) play important roles in the atmosphere as precursors of secondary air pollutants. The regional background concentrations and variation characteristics of VOCs in the atmosphere of southwestern China were studied. Meanwhile, a receptor model based on principal component analysis (PCA) was used to identify the major sources of VOCs. Weekly samples were collected in 2007 in the Gongga Mountain base station and analyzed with a three-stage preconcentration method coupled with GC-MS. The annual mean concentration of TVOCs and NMHCs were 9.40 x 10(-9) +/- 4.55 x 10(-9) and 7.73 x 10(-9) +/- 4.43 x 10(-9), respectively. Aromatic hydrocarbons provided the largest contribution to TVOCs (37.3%), follow by alkanes (30.0%) and halogenated hydrocarbons (19.8%), the smallest contribution was from alkenes (12.9%). Three major sources were resolved by the receptor model, traffic sources, biogenic sources and combustion sources. The seasonal variation of TVOCs in this area was obviously, and the order was autumn > winter > spring > summer. TVOCs concentration in autumn was very significantly higher than that in summer (P < 0.01). The seasonal variation of the four types of VOCs showed different characteristics due to the differences in photochemical properties. Isoprene emissions were from biogenic sources. Regression analysis revealed a good exponential relationship between the isoprene concentration and temperature. High temperatures increased the isoprene concentrations. However, the isoprene concentration remained constant when the ambient air temperature was below 20 degrees C. The TVOCs in Gongga Mountain were at a medium level comparing with the results of other regions, and there was a clear background station emission characteristic. PMID:23379137

  14. Microwave Studies of Chemistry of the Middle Atmosphere

    NASA Astrophysics Data System (ADS)

    Sandor, Brad J.

    The purpose of this study has been to investigate O_3 chemistry in Earth's middle atmosphere. The NRAO 12-meter radio telescope at Kitt Peak, AZ was used to observe lambda = 1 mm emission spectra of trace species at altitudes 50 -70 km. Brightness of the emission lines was used to determine abundance of the emitting species, and shapes of the pressure broadened lines were used to obtain altitude resolution of these abundances. Observations of ^{18}O^{16}O, CO, and O_3 were used to establish a calibration appropriate for atmospheric observations with a telescope primarily used for astronomical work. Diurnal variation of O_2(^1 Delta_{g}) was observed and compared with photochemical model results. Observed O_2(^1Delta_ {g}) abundances were 20% higher than model abundances, and model results can be brought into agreement with observations by reducing the rate coefficient for O_2(^1Delta_ {g}) quenching by 20% below the accepted value. The behavior of O_2(^1Delta _{g}) through the afternoon and evening was observed to agree with model calculations. Symmetric and asymmetric isotopomers of ^{50}O_3 were observed. Previous workers have found large, highly variable, and unexplained enhancements of ^{50}O _3 in the stratosphere. We extend the range of observations to the mesosphere. Significant variability in the abundance of the asymmetric isotopomer was observed. Diurnal variations of HO_2 were observed in conjunction with H_2O and O_3. Comparisons were made with photochemical model results. At mid-day HO _2 abundances were observed to be ~40% higher than model predictions. Model results for this time period can be brought into agreement with observations by reducing the rate coefficient for rm HO_2 + O--> OH + O _2 by 40%. Observed HO_2 altitude profiles in the early morning, late afternoon, and early evening are very different from model predictions.

  15. Turbulence effects in radio occultation studies of atmospheric scale heights

    NASA Technical Reports Server (NTRS)

    Eshleman, V. R.

    1975-01-01

    Atmospheric scale heights derived from radio occultation measurements of a turbulent planetary atmosphere would be accurate if the average angle of refraction through the turbulent atmosphere were equal to the refraction angle for the corresponding quiescent atmosphere. These two angles are not equal (although their difference may not be large enough to cause significant error). If necessary, it should be possible to correct for the systematic error introduced by this inequality by using measurements of signal spectra to determine characteristics of the turbulence. Sensitive dual-frequency measurements could help define the effects of turbulence in future radio occultation experiments. It does not appear that the angular offset due to turbulence has been important in past experiments, although it may become significant and require corrective analysis when improved equipment is used to probe deep into turbulent atmospheres with greater measurement precision.

  16. Study on wet scavenging of atmospheric pollutants in south Brazil

    NASA Astrophysics Data System (ADS)

    Wiegand, Flavio; Pereira, Felipe Norte; Teixeira, Elba Calesso

    2011-09-01

    The present paper presents the study of in-cloud and below-cloud SO 2 and SO 42-scavenging processes by applying numerical models in the Candiota region, located in the state of Rio Grande do Sul, South Brazil. The BRAMS (Brazilian Regional Atmospheric Modeling System) model was applied to simulate the vertical structure of the clouds, and the B.V.2 (Below-Cloud Beheng Version 2) scavenging model was applied to simulate in-cloud and below-cloud scavenging processes of the pollutants SO 2 and SO 42-. Five events in 2004 were selected for this study and were sampled at the Candiota Airport station. The concentrations of SO 2 and SO 42- sampled in the air and the simulated meteorological parameters of rainfall episodes were used as input data in the B.V.2, which simulates raindrop interactions associated with the scavenging process. Results for the Candiota region showed that in-cloud scavenging processes were more significant than below-cloud scavenging processes for two of the five events studied, with a contribution of approximately 90-100% of SO 2 and SO 42- concentrations in rainwater. A few adjustments to the original version of B.V.2 were made to allow simulation of scavenging processes in several types of clouds, not only cumulus humilis and cumulus congestus.

  17. Transport and photochemical modeling. Studies of atmospheric species

    NASA Technical Reports Server (NTRS)

    Natarajan, M.

    1987-01-01

    A program of research studies related to the photochemistry, radiative transfer, and dynamics of the stratosphere is described. Investigations were conducted in two broad areas: (1) studies of the stratospheric processes and their response to external perturbations, and (2) analysis of satellite measurements in conjunction with theoretical models. Contemporary one dimensional photochemical, radiative-convective model was used to assess the impact of perturbations such as solar flux variability, increases in atmospheric carbon dioxide, chlorofluoromethanes and other greenhouse gases. Data from satellite experiments such as LIMS and SBUV, were used along with theoretical models to develop a climatology of trace species in the stratosphere. The consistency of contemporary ozone photochemistry was examined in the light of LIMS data. Research work also includes analysis of stratospheric nitrogen dioxide distributions from different satellite experiments, investigation of the wintertime latitudinal gradients in NO2, estimation of the stratospheric odd nitrogen level and its variability, and studies related to the changes in ozone in the Antarctic, and mid latitude Southern Hemisphere.

  18. Transport and photochemical modeling. Studies of atmospheric species

    SciTech Connect

    Natarajan, M.

    1987-03-01

    A program of research studies related to the photochemistry, radiative transfer, and dynamics of the stratosphere is described. Investigations were conducted in two broad areas: (1) studies of the stratospheric processes and their response to external perturbations, and (2) analysis of satellite measurements in conjunction with theoretical models. Contemporary one dimensional photochemical, radiative-convective model was used to assess the impact of perturbations such as solar flux variability, increases in atmospheric carbon dioxide, chlorofluoromethanes and other greenhouse gases. Data from satellite experiments such as LIMS and SBUV, were used along with theoretical models to develop a climatology of trace species in the stratosphere. The consistency of contemporary ozone photochemistry was examined in the light of LIMS data. Research work also includes analysis of stratospheric nitrogen dioxide distributions from different satellite experiments, investigation of the wintertime latitudinal gradients in NO/sub 2/, estimation of the stratospheric odd nitrogen level and its variability, and studies related to the changes in ozone in the Antarctic, and midlatitude Southern Hemisphere.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Allographic agraphia: A case study

    PubMed Central

    Menichelli, Alina; Rapp, Brenda; Semenza, Carlo

    2011-01-01

    We report the case of patient MN, diagnosed with frontotemporal dementia, who exhibited a severe impairment in writing letters and words in upper-case print in the face of accurate production of the same stimuli in lower-case cursive. In contrast to her written production difficulties, MN was unimpaired in recognizing visually presented letters and words in upper-case print. We find a modest benefit of visual form cueing in the written production of upper-case letters, despite an inability to describe or report visual features of letters in any case or font. This case increases our understanding of the allographic level of letter-shape representation in written language production. It provides strong support for previous reports indicating the neural independence of different types of case and font-specific letter-shape information; it provides evidence that letter-shape production does not require explicit access to information about the visual attributes of letter shapes and, finally, it reveals the possibility of interaction between processes involved in letter-shape production and perception. PMID:18489965

  1. Case Study: The Chemistry of Cocaine

    ERIC Educational Resources Information Center

    Dewprashad, Brahmadeo

    2011-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's case study focuses on the chemistry of cocaine to teach a number of core concepts in organic chemistry. It also requires that students read and analyze an original research paper on…

  2. Case Studies for Inclusive Schools. Second Edition

    ERIC Educational Resources Information Center

    Anderson, Peggy L.

    2005-01-01

    Case Studies for "Inclusive Schools, Second Edition" presents a sampling of case studies that contain realistic problems concerning inclusion issues for teacher education students to solve. This format was chosen because the case study approach to learning is gaining in popularity as it provides students with an opportunity to apply information…

  3. Business and Consumer Education Case Studies.

    ERIC Educational Resources Information Center

    Delta Pi Epsilon, Minneapolis, Minn. Phi Chapter.

    This publication contains 58 case studies for classroom use in teaching various business and consumer education subjects at the high school level. A supplement to a previous Phi Chapter publication, "Office Education Case Studies" (1973), the case studies are intended to create class discussions and help students acquire the ability to analyze…

  4. Case Study Evaluations: A Decade of Progress?

    ERIC Educational Resources Information Center

    Yin, Robert K.

    1997-01-01

    In the last 10 years, there has been increased use of case study methodology, with accompanying refinement and improvement of the methods. Case studies have become legitimate research methods in evaluation, but it is too soon to say whether improvements in methodology are really resulting in improvements in the case studies conducted. (SLD)

  5. A new software package for detailed study of cosmic rays transport trough the Earth atmosphere

    NASA Astrophysics Data System (ADS)

    Maurchev, Eugene; Vashenyuk, Eduard; Balabin, Yury

    To study cosmic rays (CR) in the Earth atmosphere there are great number of methods both experimental and numerical. As an example, for the first can give balloon measurements, a neutron monitor research, a muon telescope research, etc. All of these experiments provide information about a particle fluxes in a given field space and have several limitations. For example, CR intensity can be estimated with using different tube counters, but in some problems it is needed to know the spectral and angular characteristics of particles in depend on altitude. This problem can be solved by numerical models of the cosmic rays propagation through the Earth atmosphere. At the present day, there are a many variations of models for a CR characteristic study, with each has its highs and lows. This paper describes a software package created in the Apatity CR laboratory. A comparison of one with similar programs and a usage examples are carried out. The important point here is result verification. As mentioned above, the experimental and numerical methods in this case only complement each other. For example, to verify the calculation results of galactic CR propagation through the Earth atmosphere a balloon experiment data is used. Another way is using a comparison with a neutron monitor data. In this work we consider this possibility, and make results.

  6. Concentrated photovoltaics, a case study

    NASA Astrophysics Data System (ADS)

    Antonini, Piergiorgio; Centro, Sandro; Golfetto, Stelvio; Saccà, Alessandro

    2014-12-01

    Concentrated Photovoltaics (CPV), once a niche technology, has now reached the maturity and reliability for large scale power generation. Especially in regions where temperatures are very high, the use of high efficiency triple junction solar cells with concentrating optics allows stable energy yield. Thus CPV can be seen as complementary and not in concurrence with silicon photovoltaics. The state of the art, the advantages and limitations of this technology will be shown. Among the main advantages of CPV is the possibility of a much higher energy supply, when compared to silicon photovoltaics, both comparing CPV and silicon with same area or the same installed power. The use of recycled and recyclable materials allows a more environmentally friendly production. The possibility to couple CPV with desalination facilities, energy storage will be analysed. As an example a case study of a CPV installation in Northern Italy is discussed. Here the use of mature technologies, derived from automotive and lighting sectors resulted in a simple and efficient module.

  7. A chamber for laboratory studies of atmospheric aerosols and clouds

    NASA Astrophysics Data System (ADS)

    Narus, M. L.; Schoenfelder, N. C.; Na, Y.; Chavasse, L. A.; Disselkamp, R. S.

    1996-12-01

    A stainless-steel chamber has been constructed and interfaced to a Fourier transform infrared spectrometer for the purpose of studying laboratory simulated atmospheric aerosols and clouds. The chamber is cylindrical in design and is comprised of a double-walled inner assembly that resides within an outer vacuum jacket. The volume of the aerosol sample region is 28 L. By circulating refrigerated methanol between the double walls of the inner assembly, constant temperature control of the sample region can be maintained between 187 and 300 K. A study of temperature uniformity within the chamber at 291, 240, and 187 K revealed a standard deviation in temperature of 1.6 K as determined from measurements made using five copper-constantan thermocouples. Good agreement is obtained between thermocouple measured temperatures and rotational temperatures computed from infrared absorption spectra of methane gas. The chamber described here has been used to examine heterogeneous chemistry of solid powder samples. A technique of generating an aerosol sample by rapidly dispersing a solid powder in a gas is presented. The half-life of a γ-alumina aerosol sample was measured to be 25 min.

  8. Microwave hyperspectral measurements for temperature and humidity atmospheric profiling from satellite: The clear-sky case

    NASA Astrophysics Data System (ADS)

    Aires, Filipe; Prigent, Catherine; Orlandi, Emiliano; Milz, Mathias; Eriksson, Patrick; Crewell, Susanne; Lin, Chung-Chi; Kangas, Ville

    2015-11-01

    This study investigates the benefits of a satellite HYperspectral Microwave Sensor (HYMS) for the retrieval of atmospheric temperature and humidity profiles, in the context of numerical weather prediction (NWP). In the infrared, hyperspectral instruments have already improved the accuracy of NWP forecasts. Microwave instruments so far only provide observations for a limited number of carefully selected channels. An information content analysis is conducted here to assess the impact of hyperspectral microwave measurements on the retrieval of temperature and water vapor profiles under clear-sky conditions. It uses radiative transfer simulations over a large variety of atmospheric situations. It accounts for realistic observation (instrument and radiative transfer) noise and for a priori information assumptions compatible with NWP practices. The estimated retrieval performance of the HYMS instrument is compared to those of the microwave instruments to be deployed on board the future generation of European operational meteorological satellites (MetOp-SG). The results confirm the positive impact of a HYMS instrument on the atmospheric profiling capabilities compared to MetOp-SG. Temperature retrieval uncertainty, compared to a priori information, is reduced by 2 to 10%, depending on the atmospheric height, and improvement rates are much higher than what will be obtained with MetOp-SG. For humidity sounding these improvements can reach 30%, a significant benefit as compared to MetOp-SG results especially below 250 hPa. The results are not very sensitive to the instrument noise, under our assumptions. The main impact provided by the hyperspectral information originates from the higher resolution in the O2 band around 60 GHz. The results are presented over ocean at nadir, but similar conclusions are obtained for other incidence angles and over land.

  9. Laboratory studies of thin films representative of atmospheric sulfate aerosol

    NASA Astrophysics Data System (ADS)

    Fortin, Tara Jean

    Sulfate aerosols are present globally in both the upper troposphere and lower stratosphere. These aerosols are of great interest because they have a profound influence on Earth's radiation balance, heterogeneous chemistry, and cloud formation mechanisms throughout the atmosphere. The magnitude of these effects is ultimately determined by the size, phase, and chemical composition of the aerosols themselves. This thesis explores some of the questions that remain concerning the phase of these aerosols under atmospheric conditions and the effects of their chemical composition on heterogeneous chemistry and cloud formation mechanisms. In the upper troposphere, cirrus clouds are thought to form via the homogeneous nucleation of ice out of dilute sulfate aerosols such as ammonium sulfate ((NH4)2SO4). To investigate this, the low-temperature phase behavior of ammonium sulfate films has been studied using Fourier transform infrared (FTIR) spectroscopy. Experiments performed as a function of increasing relative humidity demonstrate that a phase transition from crystalline (NH 4)2SO4 to a metastable aqueous solution can occur at temperatures below the eutectic at 254 K. However, on occasion, direct deposition of ice from the vapor phase was observed, possibly indicating selective heterogeneous nucleation. In addition to serving as nuclei for cirrus clouds, sulfate aerosols can participate in heterogeneous reactions. The interaction of HNO3 with ammonium sulfate has been investigated as a possible loss mechanism for gas-phase HNO3 using a Knudsen cell reactor coupled with transmission FTIR spectroscopy. The results show that HNO3 reacts with solid ammonium sulfate to produce ammonium nitrate and letovicite at 203 K. Furthermore, this reaction is enhanced as a function of relative humidity from 0 to 41%. In the lower stratosphere, polar stratospheric clouds (PSCs) are important for springtime ozone depletion. The vapor deposition of ice on sulfuric acid tetrahydrate (SAT) has

  10. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 < f42 < 0.15; 0.01 < f99 < 0.04), and negligible (f42 < 0.05; f99 < 0.01) ship influence. Application of

  11. INTERCOMPARISON STUDY OF ATMOSPHERIC MERCURY MODELS: 2. MODELING RESULTS VS. LONG-TERM OBSERVATIONS AND COMPARISON OF COUNTRY ATMOSPHERIC BALANCES

    EPA Science Inventory

    Five regional scale models with a horizontal domain covering the European continent and its surrounding seas, two hemispheric and one global scale model participated in the atmospheric Hg modelling intercomparison study. The models were compared between each other and with availa...

  12. ENVIRONMENTAL CHAMBER STUDIES OF MERCURY REACTIONS IN THE ATMOSPHERE

    EPA Science Inventory

    Mercury is released into the environment through both natural and anthropogenic pathways. The cycling and fate of mercury in atmospheric, soil, and water ecosystems is impacted by various factors, including chemical transformation and transport. An understanding of these proces...

  13. Ideas in Practice: Studies in Atmospheric Pollution For Science Teachers

    ERIC Educational Resources Information Center

    Rowe, Donald R.

    1974-01-01

    Describes the content and structure of an enviromental course offered by the Department of Engineering Technology at Western Kentucky University. The course focuses on atmospheric pollution and is designed for science teachers currently teaching in the school system. (JR)

  14. Demystifying Instructional Innovation: The Case of Teaching with Case Studies

    ERIC Educational Resources Information Center

    Kantar, Lina D.

    2013-01-01

    Issues emerging from instructional innovation are inevitable, yet basing any curriculum shift on a theoretical framework is paramount. This paper grounds the case-based pedagogy in three learning theories: behaviorism, cognitivism, and constructivism. The three theories are described and situated in relation to the case study method. An…

  15. Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme

    NASA Astrophysics Data System (ADS)

    Berkemeier, Thomas; Huisman, Andrew J.; Ammann, Markus; Shiraiwa, Manabu; Koop, Thomas; Pöschl, Ulrich

    2013-04-01

    Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass-transfer regime. Each of these regimes includes four distinct limiting cases, characterized by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different data sets for the benchmark system of oleic acid reacting with ozone. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed. Reference: Berkemeier, T., Huisman, A. J., Ammann, M., Shiraiwa, M

  16. STUDIES OF MILLIMETER-WAVE ATMOSPHERIC NOISE ABOVE MAUNA KEA

    SciTech Connect

    Sayers, J.; Bock, J. J.; Goldin, A.; Nguyen, H. T.; Golwala, S. R.; Edgington, S. F.; Lange, A. E.; Rossinot, P.; Ade, P. A. R.; Aguirre, J. E.; Haig, D.; Mauskopf, P. D.; Glenn, J.; Laurent, G. T.; Schlaerth, J.

    2010-01-10

    We report measurements of the fluctuations in atmospheric emission (atmospheric noise) above Mauna Kea recorded with Bolocam at 143 and 268 GHz from the Caltech Submillimeter Observatory. The 143 GHz data were collected during a 40 night observing run in late 2003, and the 268 GHz observations were made in early 2004 and early 2005 over a total of 60 nights. Below approx =0.5 Hz, the data time-streams are dominated by atmospheric noise in all observing conditions. The atmospheric noise data are consistent with a Kolmogorov-Taylor turbulence model for a thin wind-driven screen, and the median amplitude of the fluctuations is 280 mK{sup 2} rad{sup -5/3} at 143 GHz and 4000 mK{sup 2} rad{sup -5/3} at 268 GHz. Comparing our results with previous ACBAR data, we find that the normalization of the power spectrum of the atmospheric noise fluctuations is a factor of approx =80 larger above Mauna Kea than above the South Pole at millimeter wavelengths. Most of this difference is due to the fact that the atmosphere above the South Pole is much drier than the atmosphere above Mauna Kea. However, the atmosphere above the South Pole is slightly more stable as well: the fractional fluctuations in the column depth of precipitable water vapor are a factor of approx =sq root2 smaller at the South Pole compared to Mauna Kea. Based on our atmospheric modeling, we developed several algorithms to remove the atmospheric noise, and the best results were achieved when we described the fluctuations using a low-order polynomial in detector position over the 8' field of view. However, even with these algorithms, we were not able to reach photon-background-limited instrument photometer performance at frequencies below approx =0.5 Hz in any observing conditions. We also observed an excess low-frequency noise that is highly correlated between detectors separated by approx<(f/number sign)lambda; this noise appears to be caused by atmospheric fluctuations, but we do not have an adequate model to

  17. Studies of the Atmospheric Chemsitry of Energy-Related Volatile Organic Compounds and of their Atmospheric Reaction Products

    SciTech Connect

    Roger Atkinson; Janet Arey

    2007-04-14

    The focus of this contract was to investigate selected aspects of the atmospheric chemistry of volatile organic compounds (VOCs) emitted into the atmosphere from energy-related sources as well as from biogenic sources. The classes of VOCs studied were polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs, the biogenic VOCs isoprene, 2-methyl-3-buten-2-ol and cis-3-hexen-1-ol, alkenes (including alkenes emitted from vegetation) and their oxygenated atmospheric reaction products, and a series of oxygenated carbonyl and hydroxycarbonyl compounds formed as atmospheric reaction products of aromatic hydrocarbons and other VOCs. Large volume reaction chambers were used to investigate the kinetics and/or products of photolysis and of the gas-phase reactions of these organic compounds with hydroxyl (OH) radicals, nitrate (NO3) radicals, and ozone (O3), using an array of analytical instrumentation to analyze the reactants and products (including gas chromatography, in situ Fourier transform infrared spectroscopy, and direct air sampling atmospheric pressure ionization tandem mass spectrometry). The following studies were carried out. The photolysis rates of 1- and 2-nitronaphthalene and of eleven isomeric methylnitronaphthalenes were measured indoors using blacklamp irradiation and outdoors using natural sunlight. Rate constants were measured for the gas-phase reactions of OH radicals, Cl atoms and NO3 radicals with naphthalene, 1- and 2-methylnaphthalene, 1- and 2-ethylnaphthalene and the ten dimethylnaphthalene isomers. Rate constants were measured for the gas-phase reactions of OH radicals with four unsaturated carbonyls and with a series of hydroxyaldehydes formed as atmospheric reaction products of other VOCs, and for the gas-phase reactions of O3 with a series of cycloalkenes. Products of the gas-phase reactions of OH radicals and O3 with a series of biogenically emitted VOCs were identified and quantified. Ambient atmospheric measurements of the concentrations of a

  18. Case Studies for Effective Business Instruction.

    ERIC Educational Resources Information Center

    McAlister-Kizzier, Donna

    This book is designed as a resource for educators who teach business content in a variety of instructional settings. It contains case studies representing all functional areas of business, including corporate training, for grades 7 through graduate education. Chapter 1 provides an overview of the case study method. The history of the case method,…

  19. Study of Transitions in the Atmospheric Boundary Layer Using Explicit Algebraic Turbulence Models

    NASA Astrophysics Data System (ADS)

    Lazeroms, W. M. J.; Svensson, G.; Bazile, E.; Brethouwer, G.; Wallin, S.; Johansson, A. V.

    2016-08-01

    We test a recently developed engineering turbulence model, a so-called explicit algebraic Reynolds-stress (EARS) model, in the context of the atmospheric boundary layer. First of all, we consider a stable boundary layer used as the well-known first test case from the Global Energy and Water Cycle Experiment Atmospheric Boundary Layer Study (GABLS1). The model is shown to agree well with data from large-eddy simulations (LES), and this agreement is significantly better than for a standard operational scheme with a prognostic equation for turbulent kinetic energy. Furthermore, we apply the model to a case with a (idealized) diurnal cycle and make a qualitative comparison with a simpler first-order model. Some interesting features of the model are highlighted, pertaining to its stronger foundation on physical principles. In particular, the use of more prognostic equations in the model is shown to give a more realistic dynamical behaviour. This qualitative study is the first step towards a more detailed comparison, for which additional LES data are needed.

  20. Real-time SEM studies in controlled reactive atmospheres

    NASA Technical Reports Server (NTRS)

    Gallagher, B. D.; Garcia, A., III; Alonzo, J. R.

    1985-01-01

    A unique scanning electron accessory has been developed that allows the observation of specimens under partial pressures of any gas. The sample is placed in a metal support boat inside a special sample holder. The sample in the boat is imaged on a CRT and is simultaneously recorded on a videotape, allowing the reaction between the sample and the gas to be observed in real time. Sample changes can be seen continuously as the sample is being heated or cooled. This process allows the observation of material transformations such as phase changes as they happen. Temperatures as high as 1000 C have been used and are continuously monitored using a thermocouple with a digital display on the CRT and videotape. X-ray analyses can also be run before and after any reactions. In the study described here, thick-film screen-printing inks using molybdenum/tin compositions as a replacement for silver were developed to be used on terrestrial photovoltaic cells. Pieces were placed on the sample stage and heated in both O2 and H2 atmospheres. The results were used to determine the most effective frits to be used in the thick-film inks.

  1. Atmospheric studies from the Mars Science Laboratory Entry, Descent and Landing atmospheric structure reconstruction

    NASA Astrophysics Data System (ADS)

    Holstein-Rathlou, C.; Maue, A.; Withers, P.

    2016-01-01

    The Mars Science Laboratory (MSL) entered the martian atmosphere on Aug. 6, 2012 landing in Gale crater (4.6°S, 137.4°E) in the local mid-afternoon. Aerodynamic accelerations were measured during descent and atmospheric density, pressure and temperature profiles have been calculated from this data. Using an averaging technique developed for the NASA Phoenix Mars mission, the profiles are extended to 134.1 km, twice that of the engineering reconstruction. Large-scale temperature oscillations in the MSL temperature profile are suggestive of thermal tides. Comparing the MSL temperature profile with measured Mars Climate Sounder temperature profiles and Mars Climate Database model output highlights the presence of diurnal tides. Derived vertical wavelengths for the diurnal migrating tide are larger than predicted from idealized tidal theory, indicating an added presence of nonmigrating diurnal tides. Sub-CO2 condensation mesospheric temperatures, very similar to the Pathfinder temperature profile, allude to the possibility of CO2 clouds. This is however not supported by recent observations and models.

  2. Sensitivity Studies for Space-based Measurements of Atmospheric Total Column Carbon Dioxide Using Reflected Sunlight

    NASA Technical Reports Server (NTRS)

    Mao, Jianping; Kawa, S. Randolph

    2003-01-01

    A series of sensitivity studies is carried out to explore the feasibility of space-based global carbon dioxide (CO2) measurements for global and regional carbon cycle studies. The detection method uses absorption of reflected sunlight in the CO2 vibration-rotation band at 1.58 micron. The sensitivities of the detected radiances are calculated using the line-by-line model (LBLRTM), implemented with the DISORT (Discrete Ordinates Radiative Transfer) model to include atmospheric scattering in this band. The results indicate that (a) the small (approx.1%) changes in CO2 near the Earth's surface are detectable in this CO2 band provided adequate sensor signal-to-noise ratio and spectral resolution are achievable; (b) the effects of other interfering constituents, such as water vapor, aerosols and cirrus clouds, on the radiance are significant but the overall effects of the modification of light path length on total back-to-space radiance sensitivity to CO2 change are minor for general cases, which means that generally the total column CO2 can be derived in high precision from the ratio of the on-line center to off-line radiances; (c) together with CO2 gas absorption aerosol/cirrus cloud layer has differential scattering which may result in the modification of on-line to off-line radiance ratio which could lead a large bias in the total column CO2 retrieval. Approaches to correct such bias need further investigation. (d) CO2 retrieval requires good knowledge of the atmospheric temperature profile, e.g. approximately 1K RMS error in layer temperature, which is achievable from new atmospheric sounders in the near future; (e) the atmospheric path length, over which the CO2 absorption occurs, should be known in order to correctly interpret horizontal gradients of CO2 from the total column CO2 measurement; thus an additional sensor for surface pressure measurement needs to be attached for a complete measurement package.

  3. Atmospheres from Within

    NASA Technical Reports Server (NTRS)

    Morgan, Thomas; Abshire, James; Clancy, Todd; Fry, Ghee; Gustafson, Bo; Hecht, Michael; Kostiuk, Theodor; Rall, Jonathan; Reuter, Dennis; Sheldon, Robert

    1996-01-01

    In this review of atmospheric investigations from planetary surfaces, a wide variety of measurement and instrument techniques relevant to atmospheric studies from future planetary lander missions are discussed. The diversity of planetary surface environments within the solar system precludes complete or highly specific coverage, but lander investigations for Mars and cometary missions are presented as specific cases that represent the broad range of atmospheric-surface boundaries and that also correspond to high priority goals for future national and international lander missions.

  4. The Role of Large-Coherent-Eddy Transport in the Atmospheric Surface Layer Based on CASES-99 Observations

    NASA Astrophysics Data System (ADS)

    Sun, Jielun; Lenschow, Donald H.; LeMone, Margaret A.; Mahrt, Larry

    2016-07-01

    The analysis of momentum and heat fluxes from the Cooperative Atmosphere-Surface Exchange Study 1999 (CASES-99) field experiment is extended throughout the diurnal cycle following the investigation of nighttime turbulence by Sun et al. (J Atmos Sci 69:338-351, 2012). Based on the observations, limitations of Monin-Obukhov similarity theory (MOST) are examined in detail. The analysis suggests that strong turbulent mixing is dominated by relatively large coherent eddies that are not related to local vertical gradients as assumed in MOST. The HOckey-Stick Transition (HOST) hypothesis is developed to explain the generation of observed large coherent eddies over a finite depth and the contribution of these eddies to vertical variations of turbulence intensity and atmospheric stratification throughout the diurnal cycle. The HOST hypothesis emphasizes the connection between dominant turbulent eddies and turbulence generation scales, and the coupling between the turbulence kinetic energy and the turbulence potential energy within the turbulence generation layer in determining turbulence intensity. For turbulence generation directly influenced by the surface, the HOST hypothesis recognizes the role of the surface both in the vertical variation of momentum and heat fluxes and its boundary effect on the size of the dominant turbulence eddies.

  5. Neurology Case Studies: Cerebrovascular Disease.

    PubMed

    Farooq, Muhammad U; Gorelick, Philip B

    2016-08-01

    This article discusses interesting vascular neurology cases including the management of intracranial stenosis, migraine headache and stroke risk, retinal artery occlusions associated with impaired hearing, intracranial occlusive disease, a heritable cause of stroke and vascular cognitive impairment, and an interesting clinico-neuroradiologic disorder associated with eclampsia. PMID:27445238

  6. Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme

    NASA Astrophysics Data System (ADS)

    Berkemeier, T.; Huisman, A. J.; Ammann, M.; Shiraiwa, M.; Koop, T.; Pöschl, U.

    2013-07-01

    Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass transfer regime. Each of these regimes includes four distinct limiting cases, characterised by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different datasets for the benchmark system of oleic acid reacting with ozone in order to demonstrate utility and highlight potential issues. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed.

  7. Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme

    NASA Astrophysics Data System (ADS)

    Berkemeier, T.; Huisman, A. J.; Ammann, M.; Shiraiwa, M.; Koop, T.; Pöschl, U.

    2013-01-01

    Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass-transfer regime. Each of these regimes includes four distinct limiting cases, characterized by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different data sets for the benchmark system of oleic acid reacting with ozone. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed.

  8. A three-dimensional study of 30- to 300-MeV atmospheric gamma rays

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.

    1974-01-01

    A three-dimensional study of atmospheric gamma rays with energy greater than 30 MeV has been carried out. A knowledge of these atmospheric secondaries has significant applications to the study of cosmic gamma rays. For detectors carried on balloons, atmospherically produced gamma rays are the major source of background. For satellite detectors, atmospheric secondaries provide a calibration source. Experimental results were obtained from four balloon flights from Palestine, Texas, with a 15 cm by 15 cm digitized wire grid spark chamber. The energy spectrum for downward-moving gamma rays steepens with increasing atmospheric depth. Near the top of the atmosphere, the spectrum steepens with increasing zenith angle. A new model of atmospheric secondary production has calculated the depth, the energy, and the zenith angle dependence of gamma rays above 30 MeV, using a comprehensive three-dimensional Monte Carlo model of the nucleon-meson-electromagnetic cascade.

  9. Upper Atmosphere Research Satellite (UARS): A program to study global ozone change

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A general overview of NASA's Upper Atmosphere Research Satellite (UARS) program is presented in a broad based informational publication. The UARS will be responsible for carrying out the first systematic, comprehensive study of the stratosphere and will furnish important new data on the mesosphere and thermosphere. The UARS mission objectives are to provide an increased understanding of energy input into the upper atmosphere; global photochemistry of the upper atmosphere; dynamics of the upper atmosphere; coupling among these processes; and coupling between the upper and lower atmosphere. These mission objectives are briefly described along with the UARS on-board instrumentation and related data management systems.

  10. High-resolution studies of atmospheric IR emission spectra

    NASA Technical Reports Server (NTRS)

    Murcray, F. J.; Murcray, F. H.; Goldman, A.; Blatherwick, R. D.; Murcray, D. G.

    1991-01-01

    Atmospheric emission spectra obtained with two different spectrometer systems are presented. The first system (the BOMEM Michelson interferometer) is designed for emission work. Spectra were obtained under adverse conditions in the Antarctic, and are still of good absolute accuracy. The second system (a modified Bruker Instruments IFS120 very high spectral resolution interferometer) demonstrates the sensitivity that can be achieved even at higher spectral resolution. This system shows that mid-IR atmospheric emission spectra can be obtained with a good SNR in a reasonable length of time at a relatively high resolution. A properly designed high resolution system should achieve high accuracy, sensitivity, and resolution, thereby permitting measurements of many atmospheric constituents when solar spectra cannot be obtained.

  11. Studying Biological Responses to Global Change in Atmospheric Oxygen

    PubMed Central

    Powell, Frank L.

    2010-01-01

    A popular book recently hypothesized that change in atmospheric oxygen over geological time is the most important physical factor in the evolution of many fundamental characteristics of modern terrestrial animals. This hypothesis is generated primarily using fossil data but the present paper considers how modern experimental biology can be used to test it. Comparative physiology and experimental evolution clearly show that changes in atmospheric O2 over the ages had the potential to drive evolution, assuming the physiological O2-sensitivity of animals today is similar to the past. Established methods, such as phylogenetically independent contrasts, as well new approaches, such as adding environmental history to phylogenetic analyses or modeling interactions between environmental stresses and biological responses with different rate constants, may be useful for testing (disproving) hypotheses about biological adaptations to changes in atmospheric O2. PMID:20385257

  12. The Integrated Land Ecosystem - Atmosphere Processes Study (iLEAPS): A new Program to Study Land/Atmosphere Interactions in the Second Phase of IGBP

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.; Kabat, P.; Reissell, A.

    2004-12-01

    Recent progress in global change research has shown clearly that the Earth's environment is a complex system, defined through intricately linked processes, feedbacks and teleconnections. This integral perspective renders obsolete the conventional scientific approach of investigating disjunct causal relationships, and demands a new, integrated way of conducting environmental Earth research. To reflect this approach to Earth System Science, the new IGBP core project "Integrated Land Ecosystem - Atmosphere Processes Study" (iLEAPS) has been designed to study the interactions between land and atmosphere within the Earth System. The fundamental objective of iLEAPS is to provide understanding of how interacting physical, chemical, and biological processes transport and transform energy and matter through the land-atmosphere interface, particularly emphasizing interactions and feedbacks at all scales - from past to future and from local to global. The research planned for iLEAPS covers the basic processes that link surface-atmosphere exchange with vegetation/ecosystem processes on the one hand and with atmospheric dynamics, tropospheric chemistry and physical climate on the other. There will be four foci: 1) Land-atmosphere exchange of reactive and conservative compounds: Key interactions and feedbacks in the Earth System 2) Feedbacks between land biota, aerosols and atmospheric composition in the climate system. (a) Biosphere-aerosol-cloud-climate interactions, (b) Surface-atmosphere exchanges and the self-cleansing mechanism of the atmosphere 3) Feedbacks and teleconnections in the land surface -vegetation- water - atmosphere-system 4) Transfer of material and energy in the soil/canopy/boundary-layer system: Measurements and modelling

  13. Crossed molecular beam studies of atmospheric chemical reaction dynamics

    SciTech Connect

    Zhang, Jingsong

    1993-04-01

    The dynamics of several elementary chemical reactions that are important in atmospheric chemistry are investigated. The reactive scattering of ground state chlorine or bromine atoms with ozone molecules and ground state chlorine atoms with nitrogen dioxide molecules is studied using a crossed molecular beams apparatus with a rotatable mass spectrometer detector. The Cl + O{sub 3} {yields} ClO + O{sub 2} reaction has been studied at four collision energies ranging from 6 kcal/mole to 32 kcal/mole. The derived product center-of-mass angular and translational energy distributions show that the reaction has a direct reaction mechanism and that there is a strong repulsion on the exit channel. The ClO product is sideways and forward scattered with respect to the Cl atom, and the translational energy release is large. The Cl atom is most likely to attack the terminal oxygen atom of the ozone molecule. The Br + O{sub 3} {yields} ClO + O{sub 2} reaction has been studied at five collision energies ranging from 5 kcal/mole to 26 kcal/mole. The derived product center-of-mass angular and translational energy distributions are quite similar to those in the Cl + O{sub 3} reaction. The Br + O{sub 3} reaction has a direct reaction mechanism similar to that of the Cl + O{sub 3} reaction. The electronic structure of the ozone molecule seems to play the central role in determining the reaction mechanism in atomic radical reactions with the ozone molecule. The Cl + NO{sub 2} {yields} ClO + NO reaction has been studied at three collision energies ranging from 10.6 kcal/mole to 22.4 kcal/mole. The center-of-mass angular distribution has some forward-backward symmetry, and the product translational energy release is quite large. The reaction proceeds through a short-lived complex whose lifetime is less than one rotational period. The experimental results seem to show that the Cl atom mainly attacks the oxygen atom instead of the nitrogen atom of the NO{sub 2} molecule.

  14. DETECTING PLANETARY GEOCHEMICAL CYCLES ON EXOPLANETS: ATMOSPHERIC SIGNATURES AND THE CASE OF SO{sub 2}

    SciTech Connect

    Kaltenegger, L.; Sasselov, D.

    2010-01-10

    We study the spectrum of a planetary atmosphere to derive detectable features in low resolution of different global geochemical cycles on exoplanets-using the sulfur cycle as our example. We derive low-resolution detectable features for first generation space- and ground-based telescopes as a first step in comparative planetology. We assume that the surfaces and atmospheres of terrestrial exoplanets (Earth-like and super-Earths) will most often be dominated by a specific geochemical cycle. Here we concentrate on the sulfur cycle driven by outgassing of SO{sub 2} and H{sub 2}S followed by their transformation to other sulfur-bearing species, which is clearly distinguishable from the carbon cycle, which is driven by outgassing of CO{sub 2}. Due to increased volcanism, the sulfur cycle is potentially the dominant global geochemical cycle on dry super-Earths with active tectonics. We calculate planetary emission, reflection, and transmission spectrum from 0.4 mum to 40 mum with high and low resolution to assess detectable features using current and Archean Earth models with varying SO{sub 2} and H{sub 2}S concentrations to explore reducing and oxidizing habitable environments on rocky planets. We find specific spectral signatures that are observable with low resolution in a planetary atmosphere with high SO{sub 2} and H{sub 2}S concentration. Therefore, first generation space- and ground-based telescopes can test our understanding of geochemical cycles on rocky planets and potentially distinguish planetary environments dominated by the carbon and sulfur cycles.

  15. Passive Microwave Studies of Atmospheric Precipitation and State

    NASA Technical Reports Server (NTRS)

    Staelin, David H.; Rosenkranz, Philip W.; Shiue, James C. (Technical Monitor)

    2002-01-01

    The principal contributions of this research on novel passive microwave spectral techniques are in the areas of: (1) global precipitation mapping using the opaque spectral bands on research and operational weather satellites, (2) development and analysis of extensive aircraft observational imaging data sets obtained using the MIT instrument NAST-M near 54 and 118 GHz over hurricanes and weather ranging from tropical to polar; simultaneous data from the 8500-channel infrared spectrometer NAST-I was obtained and analyzed separately, (3) estimation of hydrometeor diameters in cell tops using data from aircraft and spacecraft, (4) continued improvement of expressions for atmospheric transmittance at millimeter and sub-millimeter wavelengths, (5) development and airborne use of spectrometers operating near 183- and 425-GHz bands, appropriate to practical systems in geosynchronous orbit, and (6) preliminary studies of the design and performance of future geosynchronous microwave sounders for temperature and humidity profiles and for continuous monitoring of regional precipitation through most clouds. This work was a natural extension of work under NASA Grant NAG5-2545 and its predecessors. This earlier work had developed improved airborne imaging microwave spectrometers and had shown their sensitivity to precipitation altitude and character. They also had prepared the foundations for precipitation estimation using the opaque microwave bands. The field demonstration and improvement of these capabilities was then a central part of the present research reported here, during which period the first AMSU data became available and several hurricanes were overflown by NAST-M, yielding unique data about their microwave signatures. This present work has in turn helped lay the foundation for future progress in incorporating the opaque microwave channels in systems for climatologically precise global precipitation mapping from current and future operational satellites. Extension of

  16. Studies of the Partitioning of Glyoxal into Atmospheric Particulates

    NASA Astrophysics Data System (ADS)

    Liggio, J.; McLaren, R.; Li, S.

    2003-12-01

    The organic composition of atmospheric aerosols is an area of very active research. Recent research has tried to elucidate possible mechanisms for incorporation of semi-volatile and volatile carbonyl products in particulates, almost all involving some sort of heterogeneous chemical reaction of carbonyl products to form less volatile species that are stabilized in the particle phase. These mechanisms include organic hydration, formation of hemiacetals and acetals, aldol condensations, and polymerization. In order to study the partitioning behaviour of volatile organic carbonyls, we have designed a 2 m3 teflon reaction chamber that uses a differential mobility analyzer - condensation nuclei counter for monitoring the physical properties of particles, an aerosol mass spectrometer (AMS) for monitoring the chemical composition of the particles and an automated DNPH cartridge/HPLC system for monitoring the gaseous composition inside the chamber. In this paper, we will discuss experiments that explore the physical and chemical characteristics of particles formed from the growth of seed particles ((NH4)2SO4, (NH4)HSO4, H2SO4, NaNO3, and NaCl) in the presence of gaseous glyoxal. The unique highlight of this system is the use of the AMS, which gives us a sensitive probe of changes in the chemical content of the particles as a function of time. The particle growth was rapid and significant and appears to be acid catalyzed, but is otherwise independent of the cationic content of the seed. Evidence is presented for the formation of hydrated glyoxal monomer, dimers, trimers and possibly higher order species. Possible mechanisms and mass spectrometric evidence will be discussed.

  17. A study of the time variability of Jupiter's atmospheric structure

    NASA Astrophysics Data System (ADS)

    Kuehn, D. M.; Beebe, R. F.

    1993-02-01

    Aspects of the time-variable nature of the Jovian atmosphere are addressed using high-resolution photometrically calibrated multicolored imaging data obtained over two Jovian apparitions. During the period of observations, Jupiter's South Equatorial Belts (SEB) underwent a drastic brightening and its Equatorial Zone gradually darkened throughout the period. Based on the data, vertically inhomogeneous atmospheric structure models are constructed and used to make direct quantitative comparisons between different latitudinal regions and different epochs. The drastic brightening of the SEB is explained by an increase in both the optical thickness and the single-scattering albedo of the upper tropospheric cloud.

  18. Experimental approaches for studying non-equilibrium atmospheric plasma jets

    NASA Astrophysics Data System (ADS)

    Shashurin, A.; Keidar, M.

    2015-12-01

    This work reviews recent research efforts undertaken in the area non-equilibrium atmospheric plasma jets with special focus on experimental approaches. Physics of small non-equilibrium atmospheric plasma jets operating in kHz frequency range at powers around few Watts will be analyzed, including mechanism of breakdown, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species, discharge current spreading, transient dynamics of various plasma parameters, etc. Experimental diagnostic approaches utilized in the field will be considered, including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, fast photographing, etc.

  19. Experimental approaches for studying non-equilibrium atmospheric plasma jets

    SciTech Connect

    Shashurin, A.; Keidar, M.

    2015-12-15

    This work reviews recent research efforts undertaken in the area non-equilibrium atmospheric plasma jets with special focus on experimental approaches. Physics of small non-equilibrium atmospheric plasma jets operating in kHz frequency range at powers around few Watts will be analyzed, including mechanism of breakdown, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species, discharge current spreading, transient dynamics of various plasma parameters, etc. Experimental diagnostic approaches utilized in the field will be considered, including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, fast photographing, etc.

  20. Saturn Uranus atmospheric entry probe mission spacecraft system definition study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The modifications required of the Pioneer F/G spacecraft design for it to deliver an atmospheric entry probe to the planets Saturn and Uranus are investigated. It is concluded that it is feasible to conduct such a mission within the constraints and interfaces defined. The spacecraft required to perform the mission is derived from the Pioneer F/G design, and the modifications required are generally routinely conceived and executed. The entry probe is necessarily a new design, although it draws on the technology of past, present, and imminent programs of planetary atmospheric investigations.

  1. Case Studies for Management Development in Bangladesh.

    ERIC Educational Resources Information Center

    McLean, Gary N.

    Eight case studies appropriate for use in a course in management development were prepared and are provided in this document. The typical case describes a real business situation in which a real manager had to reach a decision. The case gives quantitative and qualitative information that is, or may be, relevant to that decision. Questions for…

  2. Study on Case Teaching of Financial Management

    ERIC Educational Resources Information Center

    Che, Zhenghong; Che, Zhengmei

    2011-01-01

    Case teaching is an efficient teaching method of management. It plays an important role to enhance the students' ability to practice the theory. However, case teaching of financial management has not achieved the expected results. The paper aims to study the importance, characteristics and corresponding methods of case teaching method of financial…

  3. BOREAS (Boreal Ecosystem-Atmosphere Study): Global change and biosphere-atmosphere interactions in the boreal forest

    NASA Technical Reports Server (NTRS)

    Sellers, Piers J.

    1991-01-01

    The Boreal Ecosystems Atmosphere Study (BOREAS) is a cooperative field and analysis project involving elements of land surface climatology, tropospheric chemistry, and terrestrial ecology. The goal of the study is to understand the interactions between the boreal forest biome and the atmosphere in order to clarify their roles in global change. The study will be centered on two 20 by 20 km sites within the North American boreal forest region, located near the northern and southern limits of the biome. Studies based at these sites will be used to explore the roles of various environmental factors in controlling the extent and character of the biome. The sites will be the subject of surface, airborne, and satellite based observations which aim to improve understanding of the biological and physical processes and states which govern the exchanges of energy, water, carbon, and trace gases between boreal forest ecosystems and the atmosphere. Particular reference will be made to those processes and states that may be sensitive to global change. The study also aims to develop the use of remote sensing techniques to transfer understanding of the above process from local scales out to regional scales. The BOREAS project is being planned for 1992-1996, with a major field effort in 1994.

  4. Field and Laboratory Studies of Atmospheric Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Coggon, Matthew Mitchell

    This thesis is the culmination of field and laboratory studies aimed at assessing processes that affect the composition and distribution of atmospheric organic aerosol. An emphasis is placed on measurements conducted using compact and high-resolution Aerodyne Aerosol Mass Spectrometers (AMS). The first three chapters summarize results from aircraft campaigns designed to evaluate anthropogenic and biogenic impacts on marine aerosol and clouds off the coast of California. Subsequent chapters describe laboratory studies intended to evaluate gas and particle-phase mechanisms of organic aerosol oxidation. The 2013 Nucleation in California Experiment (NiCE) was a campaign designed to study environments impacted by nucleated and/or freshly formed aerosol particles. Terrestrial biogenic aerosol with > 85% organic mass was observed to reside in the free troposphere above marine stratocumulus. This biogenic organic aerosol (BOA) originated from the Northwestern United States and was transported to the marine atmosphere during periodic cloud-clearing events. Spectra recorded by a cloud condensation nuclei counter demonstrated that BOA is CCN active. BOA enhancements at latitudes north of San Francisco, CA coincided with enhanced cloud water concentrations of organic species such as acetate and formate. Airborne measurements conducted during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) were aimed at evaluating the contribution of ship emissions to the properties of marine aerosol and clouds off the coast of central California. In one study, analysis of organic aerosol mass spectra during periods of enhanced shipping activity yielded unique tracers indicative of cloud-processed ship emissions (m/z 42 and 99). The variation of their organic fraction (f42 and f 99) was found to coincide with periods of heavy (f 42 > 0.15; f99 > 0.04), moderate (0.05 < f42 < 0.15; 0.01 < f99 < 0.04), and negligible (f42 < 0.05; f99 < 0.01) ship influence. Application of

  5. Supernovae studied with a ground level atmospheric fluorescence

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.

    1972-01-01

    A monitoring experiment was undertaken late 1968 to search for photon bursts of extraterrestrial origin. The experiment and the results of the observations to date are summarized. The method of detection employs ground-based photomultiplier tubes which are sensitive to the secondary fluorescence light that would be produced when the primary pulse is absorbed in the atmosphere.

  6. SIMULATED ROADWAY EXPOSURE ATMOSPHERES FOR LABORATORY ANIMAL AND HUMAN STUDIES

    EPA Science Inventory

    We will elucidate the important characteristics that define toxicity resulting from roadway emissions and their interaction with background air. We expect that fresh whole exhaust containing ultrafine particles and vapor will confer the most potent atmosphere. These results wi...

  7. Feasibility study: Atmospheric general circulation experiment, volume 2

    NASA Technical Reports Server (NTRS)

    Homsey, R. J. (Editor)

    1981-01-01

    The feasibility analysis of the atmospheric general circulation experiment (AGCE) are documented. The analysis performed in each technical area, the rationale and substantiation for the design approaches selected for the hardware, and the design details for the baseline AGCE are presented.

  8. Academic Planning: Four Institutional Case Studies.

    ERIC Educational Resources Information Center

    Kieft, Raymond N.

    As part of a project studying intrainstitutional planning, management, and evaluation, four case studies were undertaken in 1976 of academic planning at Villa Maria College, Kansas City Metropolitan Community College District, West Virginia University, and Western Washington University. The case studies were part of an ongoing project, the…

  9. Case Studies in Neurocritical Care.

    PubMed

    Sakusic, Amra; Rabinstein, Alejandro A

    2016-08-01

    The practice of neurocritical care encompasses multiple acute neurologic and neurosurgical diseases and requires detailed knowledge of neurology and critical care. This article presents 5 cases that illustrate just some of the conditions encountered in the daily practice of neurocritical care and exemplify some of the common diagnostic, therapeutic, and prognostic challenges facing the neurointensivist. Life-threatening medical complications after severe acute ischemic stroke, seizures and extreme agitation from autoimmune encephalitis, refractory seizures after subdural hemorrhage, neurologic and systemic complications related to aneurysmal subarachnoid hemorrhage, and status epilepticus after cardiac arrest are discussed in this article. PMID:27445248

  10. Composites in manufacturing - Case studies

    SciTech Connect

    Strong, A.B. )

    1991-01-01

    The papers presented in this volume focus on 19 cases of applied technology in composites design and manufacturing, all of them dealing with specific products. Topics covered include design using composite in aerospace, innovative materials and processing, tooling, fasteners and adhesives, finishing, repair, specialty applications of composites, and applications in the automotive industry. Papers are presented on the filament winding of isogrid fuselage structures; design and use of aramid fiber in aircraft structures; resin transfer molding of a complex composite aircraft structure; and field repair of an advanced helicopter vertical fin structure.

  11. The atmospheric boundary layer evening transitions: an observational and numerical study from two different datasets

    NASA Astrophysics Data System (ADS)

    Sastre, Mariano; Yagüe, Carlos; Román-Cascón, Carlos; Maqueda, Gregorio; Ander Arrillaga, Jon

    2015-04-01

    In this work we study the temporal evolution of the Atmospheric Boundary Layer (ABL) along the transition period from a diurnal typical convection to a nocturnal more frequently stable situation. This period is known as late afternoon or evening transition, depending on the specific definitions employed by different authors [1]. In order to obtain a proper characterization, we try to learn whether or not the behaviour of these transitional boundary layers is strongly dependent on local conditions. To do so, two sets of evening transitions are studied from data collected at two different experimental sites. These locations correspond to research facilities named CIBA (Spain) and CRA (France), which are the places where atmospheric field campaigns have been conducted during the last years, such as CIBA2008 and BLLAST 2011, respectively. In order to get comparable situations, we focus especially on transitions with weak synoptic forcing, and consider daily astronomical sunset as a reference time. A statistical analysis on main parameters related to the transition is carried out for both locations, and the average behaviour is shown as well as extreme values according to the timing. A similar pattern in the qualitative evolution of many variables is found. Nevertheless, several relevant differences in the progress of key variables are obtained too. Moisture, both from the soil and the air, is thought to have great relevance in explaining many of the differences found between the two sites. Some case studies are explored, focusing on the role played by the atmospheric turbulence. Complementary, numerical experiments are also performed using the Weather Research and Forecast (WRF) mesoscale model, in order to test the role of humidity, by artificially varying it in some of the simulations. [1] Lothon, M. and coauthors (2014): The BLLAST field experiment: Boundary-Layer Late Afternoon and Sunset Turbulence. Atmos. Chem. Phys., 14, 10931-10960.

  12. Study of strong interaction between atmosphere and solid Earth by using hurricane data

    NASA Astrophysics Data System (ADS)

    Tanimoto, Toshiro

    2016-04-01

    The original energy of seismic noise is in the atmosphere although the most well-known seismic noise (microseism) gets excited through the ocean, i.e. the atmosphere (winds) excites ocean waves that in turn generate seismic noise in the solid earth. The oceans work as an intermediary in this case. But there is some seismic noise that is directly caused by the atmosphere-solid earth interactions. An extreme example for such a direct interaction can be found in the case of hurricanes (tropical cyclones) when they landfall and move on land. If we had such data, we could study the process of atmosphere-solid earth interactions directly. The Earthscope TA (Transportable Array) provided a few examples of such landfallen hurricanes which moved through the TA that had both seismometers and barometers. This data set allows us to study how ground motions changed as surface pressure (i.e., the source strength) varied over time. Because effects of surface pressure show up at short distances more clearly, we first examine the correlation between pressure and ground motion for the same stations. Plots of vertical ground velocity PSD (Power Spectral Density) vs. surface pressure PSD show that there are no significant ground motions unless pressure PSD becomes larger than 10 (Pa^2/s). Above this threshold, ground motion increases as P**1.69 (P is pressure and 1.69 is close to 5/3). Horizontal ground motions are larger than vertical ground motions (in seismic data), approximately by a factor of 10-30. But we note that the variations of horizontal motions with pressure show a linear relationship. Considering the instrumental design of TA stations, this is more likely due to the tilt of the whole recording system as (lateral) strong winds apply horizontal force on it. This linear trend exists for the whole range of the observed pressure PSD data, extending to small pressure values. We interpret that tilt signals overwhelmed other seismic signals in horizontal seismograms for

  13. Case studies in conservation science

    NASA Astrophysics Data System (ADS)

    Bisulca, Christina

    The research presented in this dissertation covers three separate topics of conservation as defined by the National Science Foundation: 1) Materials Stabilization, Strengthening, Monitoring, and Repair; 2. Understanding Material Degradation and Aging; and 3) Materials and Structural Characterization of Cultural Heritage Objects (the 'technical study'). The first topic is addressed through a study to assess the consolidant tetraethoxysilane for the stabilization of alum treated wood. Falling under materials degradation studies is a study published in American Museum Novitates to understand how environmental conditions affect the aging of fossil resins from five different deposits. Two separate studies are included in technical study of cultural heritage objects which comprises the third research area of materials characterization. The first is a survey of red dyes used in Chinese paintings from the Ming Dynasty to the Early Republic (1364-1911). The second is a study of the pigments, dyes and binders used in Hawaiian barkcloth (kapa) from the 19th century.

  14. Regional conditions during the 25 October 1986 FIRE cirrus/altocumulus case study

    NASA Technical Reports Server (NTRS)

    Starr, David; Sassen, Kenneth

    1990-01-01

    The regional cloud and meteorological conditions are described for this case using satellite imagery (GOES), dual polarization lidar data, NWS radar, NMC analyses, rawinsonde data including special soundings, and analyzed vertical motions. These observations are interpreted with respect to relationships between the observed cloud characteristics and corresponding atmospheric structure. Similarities with the 27 to 28 Oct. FIRE Cirrus Case Study are noted.

  15. Study of organic pollutants oxidation by atmospheric plasma discharge

    NASA Astrophysics Data System (ADS)

    Gumuchian, Diane; Cavadias, Simeon; Duten, Xavier; Tatoulian, Michael; da Costa, Patrick; Ognier, Stephanie

    2013-09-01

    Ozonation is one of the usual steps in water treatment processes. However, some organic molecules (acetic acid) cannot be decomposed during ozonation. In that context, we are developing an Advanced Oxidation Process based on the use of a needle plate discharge at atmospheric pressure. The process is a reactor with a plasma discharge between a high voltage electrode and the solution in controlled atmosphere. Characterizations of the plasma obtained in different atmospheres were carried out (Optical Emission Spectroscopy, iCCD camera observations, etc). The efficiency of the process was evaluated by the percentage of degradation of the model-pollutant, measured by liquid chromatography analysis. Treatments in nitrogen lead to the formation of NOx species that decrease the efficiency of the process. Indeed, NOx lead to the consumption of actives species created. Treatments in argon are the most efficient. Two hypotheses are considered: (i) metastable argon participates to the degradation of acetic acid or to the formation of radicals (ii) discharges in argon lead to the formation of many streamers of low energy that increase the interface plasma/solution.

  16. Theoretical studies of important processes in planetary and comet atmospheres

    NASA Technical Reports Server (NTRS)

    Guberman, Steven L.

    1991-01-01

    This is the fifth semi-annual progress report describing research on dissociative recombination reactions in planetary and comet atmospheres. The Appendix has two papers that describe NASA supported research. Both papers have been recently accepted for publication. The first paper, 'The Generation of O(S-1) from the Dissociative Recombination of O2(+)', describes in detail the Multichannel Quantum Defect (MQDT) theory used for the calculation of dissociative recombination (DR) cross sections and rates. The application to the generation of the upper state of the atomic oxygen green line emission is of great importance to the modelling of planetary atmospheres. The second paper in the Appendix, 'Dissociative Recombination of the Ground State of N2(+)', applies the methods described in the first paper to N2(+). We find remarkable agreement with the prior microwave afterglow experiments for both the total recombination rate and for its electron temperature dependence. However, the results disagree with recent merged beams results which gave cross sections that are a factor of five below the microwave afterglow experiments and the current results. DR of N2(+) is an important mechanism for generating energetic N atoms which can escape the atmosphere of Mars. Currently we are also continuing additional work on the DR of O2(+) which is aimed at calculating both the total DR rate as a function of ion vibrational level and the rate for production of O(D-1).

  17. Case-Control Study of Writer's Cramp

    ERIC Educational Resources Information Center

    Roze, E.; Soumare, A.; Pironneau, I.; Sangla, S.; de Cock, V. Cochen; Teixeira, A.; Astorquiza, A.; Bonnet, C.; Bleton, J. P.; Vidailhet, M.; Elbaz, A.

    2009-01-01

    Task-specific focal dystonias are thought to be due to a combination of individual vulnerability and environmental factors. There are no case-control studies of risk factors for writer's cramp. We undertook a case-control study of 104 consecutive patients and matched controls to identify risk factors for the condition. We collected detailed data…

  18. A Constructive Controversy Approach to "Case Studies"

    ERIC Educational Resources Information Center

    Bird, Sharon R.; Erickson, Karla A.

    2010-01-01

    On the basis of analysis of student responses to a case study titled "Drinks and Dinner," the authors evaluate the pedagogical potential of using constructive controversy case studies to teach about inequality. "Drinks and Dinner" is designed to capture the complexity of social interactions that defy simple solutions to engage students in…

  19. Self-Employment Training Programs: Case Studies.

    ERIC Educational Resources Information Center

    Lamb, Melissa, Ed.; And Others

    This self-employment training program case study booklet has been developed for general use in exploring the feasibility of this kind of development tool. The case studies describe a number of comprehensive, self-employment training and assistance programs, from the local to the national level. Chapter II includes information on the training plan,…

  20. Chemical Case Studies: Science-Society "Bonding."

    ERIC Educational Resources Information Center

    Hofstein, Avi; Nae, Nehemia

    1981-01-01

    Describes a unit designed to illustrate the "science-society-technology connection," in which three case studies of the chemical industry in Israel are presented to high school chemistry students. Chosen for the unit are case studies on copper production in Timna, on plastics, and on life from the Dead Sea. (CS)

  1. Twenty Techniques for Teaching with Case Studies

    ERIC Educational Resources Information Center

    Sudzina, Mary R.

    2005-01-01

    Problem-based learning and teaching with case studies are instructional approaches that are increasingly being applied in a variety of disciplines, such as business, law, medicine, and education. Instructors who have experienced traditional, teacher-centered instruction are often looking for ways to successfully integrate case studies, a…

  2. Using Case Studies: An International Approach

    ERIC Educational Resources Information Center

    McClam, Tricia; Woodside, Marianne

    2005-01-01

    Case studies as an instructional strategy have been used in many disciplines, including law, teacher education, science, medicine, and business. Among the benefits of this method of instruction are involving students in learning, developing their critical thinking skills, promoting communication, and engaging in critical analysis. Case studies are…

  3. Library Media Center Problems: Case Studies.

    ERIC Educational Resources Information Center

    Coburn, Louis

    Problems which arise in school library media centers are considered, using the case study method. The 30 case studies cover: problems in child management; the librarian's role in reading instruction and guidance, and in teaching library skills; conflicting opinions on the management and objectives of the media center; the librarian's role and job…

  4. Collaboration in Distance Education. International Case Studies.

    ERIC Educational Resources Information Center

    Moran, Louise, Ed.; Mugridge, Ian, Ed.

    This book contains nine case studies of collaboration in distance education. The case studies focus on such aspects of collaboration in distance education as the following: roles of individual institutional partners; importance of personal relationships; benefits of collaboration to individual partners; conflicts between collaboration and…

  5. Teaching Case Studies: A Collaborative Approach.

    ERIC Educational Resources Information Center

    Buffington, James R.; Harper, Jeffrey S.

    Many of the Association to Advance Collegiate Schools of Business (AACSB) accredited schools require undergraduate Management Information Systems (MIS) majors to take a course in the management of information technology. Over half of these schools utilize case studies in the teaching of this course. The authors emphasize that case studies are an…

  6. A Case Study of "Empathetic Teaching Artistry"

    ERIC Educational Resources Information Center

    Risner, Doug

    2014-01-01

    This case study is one of twenty cases derived from Anderson and Risner's international study of teaching artists in dance, and theatre, which investigated participants' (n=172) artistic and academic preparation in dance, and theatre, initial entry into the teaching artist field, rewards, challenges, and obstacles in participants'…

  7. Case Studies for Teaching Students with Dyslexia

    ERIC Educational Resources Information Center

    Macnamara, Gael R.

    2004-01-01

    This easy-to-use book of case studies helps you recognize the signs of dyslexia and prescribe effective teaching strategies for students with dyslexia. It includes a Case Study Analysis Sheet so you can work through important aspects of a student's personal, academic, and social life. You can then compare what you've compiled to the author's…

  8. Is Pain Suffering? A Case Study

    ERIC Educational Resources Information Center

    Black, Helen K.

    2007-01-01

    In this article, the case study of an elderly woman shows how bodily pain and suffering meld in her narrative, not as the subjective and objective sides of the same event, but as distinct experiences in which both constructs emerge separately or come together based on the meaning she imputes to the event. The case study shows the clear…

  9. Iowa College Student Aid Commission Case Study

    ERIC Educational Resources Information Center

    Leigh, Rachel A.

    2007-01-01

    The purpose of this descriptive case study was to trace the policy production process of a state agency, the Iowa College Student Aid Commission (Commission), to its function today. This case study relied on a review of federal and state statutes, a news article search, biennium reports of the Commission, and information obtained from the…

  10. Case stories in general practice: a focus group study

    PubMed Central

    Abildsnes, Eirik; Flottorp, Signe; Stensland, Per

    2012-01-01

    Objectives To explore the interactive process of sharing case stories in small-group activity in general practice. Design Qualitative focus group study. Setting Peer-group meetings of doctors attending specialist training or continuous medical education in general practice. Participants Twenty female and 30 male doctors working in general practice in Norway. Results The storyline of case presentations included detailed stories with emotional engagement, co-authored by other group members. The stories initiated discussions and reflections concerning patients’ and doctors’ perspectives, medical ethics as well as clinical problems. The safe atmosphere allowed testing out boundaries of socially shared knowledge. Conclusions Sharing case stories in small groups in general practice initiated interaction that facilitated meaning-making, reflection and peer support. PMID:22874630

  11. Study of atmospheric parameters measurements using MM-wave radar in synergy with LITE-2

    NASA Technical Reports Server (NTRS)

    Andrawis, Madeleine Y.

    1994-01-01

    The Lidar In-Space Technology Experiment, (LITE), has been developed, designed, and built by NASA Langley Research Center, to be flown on the space shuttle 'Discovery' on September 9, 1994. Lidar, which stands for light detecting and ranging, is a radar system that uses short pulses of laser light instead of radio waves in the case of the common radar. This space-based lidar offers atmospheric measurements of stratospheric and tropospheric aerosols, the planetary boundary layer, cloud top heights, and atmospheric temperature and density in the 10-40 km altitude range. A study is being done on the use, advantages, and limitations of a millimeterwave radar to be utilized in synergy with the Lidar system, for the LITE-2 experiment to be flown on a future space shuttle mission. The lower atmospheric attenuation, compared to infrared and optical frequencies, permits the millimeter-wave signals to penetrate through the clouds and measure multi-layered clouds, cloud thickness, and cloud-base height. These measurements would provide a useful input to radiation computations used in the operational numerical weather prediction models, and for forecasting. High power levels, optimum modulation, data processing, and high antenna gain are used to increase the operating range, while space environment, radar tradeoffs, and power availability are considered. Preliminary, numerical calculations are made, using the specifications of an experimental system constructed at Georgia Tech. The noncoherent 94 GHz millimeter-wave radar system has a pulsed output with peak value of 1 kW. The backscatter cross section of the particles to be measured, that are present in the volume covered by the beam footprint, is also studied.

  12. Study of atmospheric parameters measurements using MM-wave radar in synergy with LITE-2

    NASA Astrophysics Data System (ADS)

    Andrawis, Madeleine Y.

    1994-12-01

    The Lidar In-Space Technology Experiment, (LITE), has been developed, designed, and built by NASA Langley Research Center, to be flown on the space shuttle 'Discovery' on September 9, 1994. Lidar, which stands for light detecting and ranging, is a radar system that uses short pulses of laser light instead of radio waves in the case of the common radar. This space-based lidar offers atmospheric measurements of stratospheric and tropospheric aerosols, the planetary boundary layer, cloud top heights, and atmospheric temperature and density in the 10-40 km altitude range. A study is being done on the use, advantages, and limitations of a millimeterwave radar to be utilized in synergy with the Lidar system, for the LITE-2 experiment to be flown on a future space shuttle mission. The lower atmospheric attenuation, compared to infrared and optical frequencies, permits the millimeter-wave signals to penetrate through the clouds and measure multi-layered clouds, cloud thickness, and cloud-base height. These measurements would provide a useful input to radiation computations used in the operational numerical weather prediction models, and for forecasting. High power levels, optimum modulation, data processing, and high antenna gain are used to increase the operating range, while space environment, radar tradeoffs, and power availability are considered. Preliminary, numerical calculations are made, using the specifications of an experimental system constructed at Georgia Tech. The noncoherent 94 GHz millimeter-wave radar system has a pulsed output with peak value of 1 kW. The backscatter cross section of the particles to be measured, that are present in the volume covered by the beam footprint, is also studied.

  13. A case study of embarrassment.

    PubMed

    Dann, O T

    1977-01-01

    The psychoanalytic references to embarrassment are reviewed. Embarrassment, in the literature, is seen largely as an affect involving exhibitionistic and scopophilic conflicts and defenses against these. A case in which embarrassment was prominent is discussed. Embarrassment in the patient was an ego response which implied an external object for its manifestation. It involved exhibitionistic and scopophilic conflicts and projective defenses, but also operated in ego-gratifying and adaptive ways. Her embarrassment was understood through the analysis of an initial embarrassing dream of nakedness and other dreams and associated material as the defensive out-grouth of repeated exposures to the primal scene. Embarrassment was a resistance to remembering in the analysis, and the primal-scene experiences were partially reconstructed. The analytic situation was, in many ways, a symbolic re-creation of the primal scene, including the patient's response of embarrassment. The development of embarrassment in the patient's childhood was furthered and confirmed by its being an identification with the attitudes of both parents. Finally, some reflections on embarrassment and shame in its various forms are set forth. PMID:560404

  14. Modern midwifery: two case studies.

    PubMed

    Anderson, S

    1985-01-01

    To gain more understanding of the practices of modern midwives, 2 births occurring in a Botswanan District Hospital Maternity Ward were observed by a research assistant. Naturalistic observation was considered more reliable than interviews with either patients or modern midwives to assess the biosocial aspects of birth in the modern sector. At admission to the labor room, these 2 midwives checked the patient's blood pressure, performed a vaginal examination, checked the fetal heart, palpated the uterus, shaved the public hair, and administered an enema. Both midwives did not communicate with their patients during these procedures or offer information on the results. The patients were told not to push; 1 midwife commented, "In the hospital, nobody delivers by herself." Rather, patients were instructed to do their "breathing exercises," a term with which they were not familiar and was not explained. In the 1st case, an episiotomy was performed. Both births were uneventful in terms of complications, but marked by a lack of attention to the psychological needs of the patient or sufficient explanations as to the progress of the delivery. Overall, all communications between the modern midwives observed and their patients were impersonal, with an emphasis on technical procedures. PMID:12282440

  15. Five case studies of multifamily weatherization programs

    SciTech Connect

    Kinney, L; Wilson, T.; Lewis, G.; MacDonald, M.

    1997-12-31

    The multifamily case studies that are the subject of this report were conducted to provide a better understanding of the approach taken by program operators in weatherizing large buildings. Because of significant variations in building construction and energy systems across the country, five states were selected based on their high level of multifamily weatherization. This report summarizes findings from case studies conducted by multifamily weatherization operations in five cities. The case studies were conducted between January and November 1994. Each of the case studies involved extensive interviews with the staff of weatherization subgrantees conducting multifamily weatherization, the inspection of 4 to 12 buildings weatherized between 1991 and 1993, and the analysis of savings and costs. The case studies focused on innovative techniques which appear to work well.

  16. Theoretical pluralism in psychoanalytic case studies

    PubMed Central

    Willemsen, Jochem; Cornelis, Shana; Geerardyn, Filip M.; Desmet, Mattias; Meganck, Reitske; Inslegers, Ruth; Cauwe, Joachim M. B. D.

    2015-01-01

    The aim of this study is to provide an overview of the scientific activity of different psychoanalytic schools of thought in terms of the content and production of case studies published on ISI Web of Knowledge. Between March 2013 and November 2013, we contacted all case study authors included in the online archive of psychoanalytic and psychodynamic case studies (www.singlecasearchive.com) to inquire about their psychoanalytic orientation during their work with the patient. The response rate for this study was 45%. It appears that the two oldest psychoanalytic schools, Object-relations psychoanalysis and Ego psychology or “Classical psychoanalysis” dominate the literature of published case studies. However, most authors stated that they feel attached to two or more psychoanalytic schools of thought. This confirms that the theoretical pluralism in psychoanalysis stretches to the field of single case studies. The single case studies of each psychoanalytic school are described separately in terms of methodology, patient, therapist, or treatment features. We conclude that published case studies features are fairly similar across different psychoanalytic schools. The results of this study are not representative of all psychoanalytic schools, as some do not publish their work in ISI ranked journals. PMID:26483725

  17. An evaluation of a coupled atmosphere-ocean modelling system for regional climate studies: extreme events in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Mooney, Priscilla A.; Mulligan, Frank J.

    2013-04-01

    We investigate the ability of a coupled regional atmosphere-ocean modelling system to simulate two extreme events in the North Atlantic. In this study we use the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST; Warner et al.) modelling system with only the atmosphere and ocean models activated. COAWST couples the atmosphere model (Weather Research and Forecasting model; WRF) to the ocean model (Regional Ocean Modelling System; ROMS) with the Model Coupling Toolkit. Results from the coupled system are compared with atmosphere only simulations of North Atlantic storms to evaluate the performance of the coupled modelling system. Two extreme events (Hurricane Katia and Hurricane Irene) were chosen to assess the level of improvement (or otherwise) arising from coupling WRF with ROMS. These two hurricanes involve different dynamics and present different challenges to the modeling system. This provides a robust assessment of the advantages or disadvantages of coupling WRF with ROMS for regional climate modelling studies of extreme events in the North Atlantic. We examine the ability of the coupled modelling system to simulate these two extreme events by comparing modelled storm tracks, storm intensities, wind speeds and sea surface temperatures with observations in all cases. The effect of domain size, and two different planetary boundary layers used in WRF are also reported.

  18. Electrical studies and plasma characterization of an atmospheric pressure plasma jet operated at low frequency

    SciTech Connect

    Giuliani, L.; Xaubet, M.; Grondona, D.; Minotti, F.; Kelly, H.

    2013-06-15

    Low-temperature, high-pressure plasma jets have an extensive use in medical and biological applications. Much work has been devoted to study these applications while comparatively fewer studies appear to be directed to the discharge itself. In this work, in order to better understand the kind of electrical discharge and the plasma states existing in those devices, a study of the electrical characteristics of a typical plasma jet, operated at atmospheric pressure, using either air or argon, is reported. It is found that the experimentally determined electrical characteristics are consistent with the model of a thermal arc discharge, with a highly collisional cathode sheet. The only exception is the case of argon at the smallest electrode separation studied, around 1 mm in which case the discharge is better modeled as either a non-thermal arc or a high-pressure glow. Also, variations of the electrical behavior at different gas flow rates are interpreted, consistently with the arc model, in terms of the development of fluid turbulence in the external jet.

  19. Experimental studies of the overshoot and undershoot in pulse-modulated radio-frequency atmospheric discharge

    NASA Astrophysics Data System (ADS)

    Huo, W. G.; Li, R. M.; Shi, J. J.; Ding, Z. F.

    2016-08-01

    The overshoot and undershoot of the applied voltage on the electrodes, the discharge current, and radio frequency (RF) power were observed at the initial phase of pulse-modulated (PM) RF atmospheric pressure discharges, but factors influencing the overshoot and undershoot have not been fully elucidated. In this paper, the experimental studies were performed to seek the reasons for the overshoot and undershoot. The experimental results show that the overshoot and undershoot are associated with the pulse frequency, the rise time of pulse signal, and the series capacitor Cs in the inversely L-shaped matching network. In the case of a high RF power discharge, these overshoot and undershoot become serious when shortening the rise time of a pulse signal (5 ns) or operating at a moderate pulse frequency (500 Hz or 1 kHz).

  20. Outage management: A case study

    SciTech Connect

    Haber, S.B.; Barriere, M.T. ); Roberts, K.H. . Walter A. Haas School of Business)

    1992-01-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission's (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  1. Outage management: A case study

    SciTech Connect

    Haber, S.B.; Barriere, M.T.; Roberts, K.H.

    1992-09-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission`s (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  2. Study of atmospheric pollution scavenging. Eighteenth progress report

    SciTech Connect

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

    1980-07-01

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

  3. Atmospheric Modelling for Air Quality Study over the complex Himalayas

    NASA Astrophysics Data System (ADS)

    Surapipith, Vanisa; Panday, Arnico; Mukherji, Aditi; Banmali Pradhan, Bidya; Blumer, Sandro

    2014-05-01

    An Atmospheric Modelling System has been set up at International Centre for Integrated Mountain Development (ICIMOD) for the assessment of Air Quality across the Himalaya mountain ranges. The Weather Research and Forecasting (WRF) model version 3.5 has been implemented over the regional domain, stretching across 4995 x 4455 km2 centred at Ichhyakamana , the ICIMOD newly setting-up mountain-peak station (1860 m) in central Nepal, and covering terrains from sea-level to the Everest (8848 m). Simulation is carried out for the winter time period, i.e. December 2012 to February 2013, when there was an intensive field campaign SusKat, where at least 7 super stations were collecting meteorology and chemical parameters on various sites. The very complex terrain requires a high horizontal resolution (1 × 1 km2), which is achieved by nesting the domain of interest, e.g. Kathmandu Valley, into 3 coarser ones (27, 9, 3 km resolution). Model validation is performed against the field data as well as satellite data, and the challenge of capturing the necessary atmospheric processes is discussed, before moving forward with the fully coupled chemistry module (WRF-Chem), having local and regional emission databases as input. The effort aims at finding a better understanding of the atmospheric processes and air quality impact on the mountain population, as well as the impact of the long-range transport, particularly of Black Carbon aerosol deposition, to the radiative budget over the Himalayan glaciers. The higher rate of snowcap melting, and shrinkage of permafrost as noticed by glaciologists is a concern. Better prediction will supply crucial information to form the proper mitigation and adaptation strategies for saving people lives across the Himalayas in the changing climate.

  4. Atmospheric Tides over the Pyrenees. Observational study and numerical simulation

    NASA Astrophysics Data System (ADS)

    Diaz de Argandoña, Javier; Ezcurra, Agustin; Saenz, Jon; Campistron, Bernard; Ibarra-Berastegi, Gabriel; Saïd, Frederique

    2010-05-01

    Atmospheric tides refer to the oscillations in the atmosphere whose periods are integral fractions of a day. In some magnitudes (e.g. temperature), these oscillations are quite evident but in others, such as the pressure in the midlatitudes, they are usually masked by the greater variations produced during the transient pass of synoptic weather systems. The main forcing agent for these oscillations, as opposed to ocean tides, is not the solar or lunar gravity pull, but the daily variations in solar insolation and the thermal effect derived from it. The main components of the solar atmospheric tides are the semidiurnal, with a 12-hour period, and the 24-hour period component or diurnal tide. The global scale tides are usually referred to as migrating tides, and are the result of a gravity wave which travels westerly with the apparent motion of the sun. Nevertheless, a significant part of the tide can be related to local characteristics, and this part is considered as the non-migrating component of the tide. Barometric tides around the Pyrenees mountain range are analyzed by means of ground synoptic stations data recorded during one year, ground data from PYREX experiment and the CRA/LA VHF wind profiler installed in the North of the range. Tides are decomposed in their diurnal and semidiurnal components. Diurnal tides show a strong non migrating component and are very dependent on local conditions. Semidiurnal tides are more homogeneous and present a north-south asymmetry, also noted in the Alps. This cross-range asymmetry seems to be related to some interference effect caused by the mountain range in the migrating semidiurnal tide wave. The diurnal component asymmetry presents a very strong seasonal variation, so its cause must be probably related to thermal local conditions. A three month simulation carried out with NCAR's WRF limited area model reproduces this asymmetry and some of the features of the observed tides.

  5. Case Studies in Literacy Development.

    ERIC Educational Resources Information Center

    Purvis, Don

    The report details results of a research project to monitor and map the literacy development of three learners of English as a Second Language (ESL) studying in an Australian English program for adult migrants. The objective was to gain a longitudinal picture of their reading and writing development over a period of nine months. Five additional…

  6. Work on the Super and the Study of Atmospheric Ignition

    NASA Astrophysics Data System (ADS)

    Hull, Mcallister

    2001-03-01

    By 1951, the group of young faculty (Bob Gluckstern and me), post doctoral fellows and graduate students, was comfortably established in Sloane Laboratory, and as "The Breit Group", in the department of physics at Yale. We didn't consciously separate ourselves from others in the department, and no one seemed to put us apart, but the association with Breit gave us a special "aura"--sometimes as objects of pity. Any project that involved the group as a whole, or a significant part of it, was discussed with Bob and me, and sometime in 1951 Breit called us in to consider a request that we look at the possibility of atmospheric ignition by a "Super" - as we still called it then, after Edward Teller. At the end of my stay at Los Alamos, in the summer of 1946, we youngsters had many bull sessions about that "Super", and the possibility of controlled fusion energy. We were confident that the former would be working in perhaps five years, and the latter within ten. After all, Han Bethe had shown us how the sun made its energy, and all that was needed to do was to replace a couple of his slow beta decays with something faster. As I write, some fifty-four years later, we still haven't got fusion energy for power. Our crystal balls were cloudier than Vicky Weisskopf's were to be! But I knew some of the lingo, and had worked out the way radiation penetrates the atmosphere (for understanding the Bikini tests), so in 1951, initially drew the task of looking at opacity, a key question in the bomb itself, and in the possibility of atmospheric ignition. Most of our limited work on the bomb was checking calculations that had been done by others as the Teller-Ulam design was being put together. At least some work on atmospheric ignition had already been done as well, but Teller wanted the "most careful physicist he knew" to do the definitive calculations, so Breit got the call. I do not recall all the members of the group who worked on the project and for that I apologize - no private

  7. A Case Study of Engineering Ethics

    NASA Astrophysics Data System (ADS)

    Shimizu, Kazuo

    In Engineering Ethics Class at Shizuoka University, the Code of Ethics and Cases for Electrical Engineers by IEEJ Ethics committee is used to promote for high education effect to correspond large number of students (140students). In this paper, a case study in the class, and survey results for ethics value of students are presented. In addition, some comments for role playing act on the case of virtual experiences by students are described.

  8. Labyrinthine sequestrum: four case studies.

    PubMed

    Lao, Zheng; Sha, Yan; Chen, Bing; Dai, Chun-Fu; Huang, Wen-Hu; Cheng, Yu-Shu

    2012-09-01

    Labyrinthine sequestrum, a rare form of labyrinthitis, is highly distinct from the more commonly encountered labyrinthitis ossificans based on its unique clinical, radiologic, and histologic characteristics. The study included 4 such patients who had undergone clinical and laboratory investigations, computed tomography (CT), and magnetic resonance imaging (MRI) assessments followed by surgical procedures and pathological evaluation. Their major symptoms were otorrhea, otalgia, tinnitus, and profound hearing loss. Imaging studies showed an osteolytic soft mass with calcified debris in the inner ear, and the bony labyrinth was eroded partly or completely by granulation mass, with loss of bony morphology. Further pathological examination was coincident with inflammatory granulation tissue with some calcification or osseous tissue. The disease process is attributed to chronic osteomyelitis due to the presence of osteonecrosis. Prompt CT and MRI examinations and optimal therapeutic management facilitate definitive diagnosis and protect against fatal complications. PMID:22467283

  9. Effects of Outer Plasmasphere Processes on Atmospheric Precipitation: A Multipoint Observational Study

    NASA Astrophysics Data System (ADS)

    Erickson, P. J.; Foster, J. C.; Coster, A. J.; Halford, A.; Millan, R. M.; Wygant, J. R.

    2014-12-01

    Earth's inner and outer radiation belts are surrounded by a natural high intensity radiation environment, composed of high energy and relativistic particles. The dynamic outer plasmasphere overlaps the outer radiation belt beyond L=2.5 and can play a key role in modulating the outer radiation belt. In particular, ambient cold plasma density associated with plasmaspheric structure and density gradients in the plasmasphere boundary layer (PBL) can regulate the occurrence and characteristics of wave-particle interactions (WPI) leading to large changes in precipitation/loss efficiency. These interactions are efficient at scattering high energy particles into the atmospheric loss cone, resulting in spatially localized enhancements in outer radiation belt acceleration and precipitation. We discuss a multi-point observational case study of the relationship of dayside radiation belt precipitation temporal and spatial dynamics to outer plasmasphere processes during a coronal mass ejection driven shock injection and plasmasphere reconfiguration event on 2014-01-09. We combine in-situ magnetosphere diagnostics from the Van Allen Probes A and B spacecraft with in-situ data from multiple BARREL balloons measuring atmospheric precipitation in the afternoon MLT sector, near the Van Allen Probes magnetic footprints. Van Allen Probes and THEMIS E data from their respective EFW instruments determines electric field structure and thermal electron density configurations to L~7. Finally, we place the in-situ diagnostics in a larger context using GPS ground based total electron content observations of L <= 4 wide field plasmaspheric structure and PBL dynamics. We present analysis explaining the observed atmospheric precipitation, and demonstrating the significance of the outer plasmasphere boundary location in processes leading to energetic electron precipitation. Such multi-instrument analysis demonstrates that consideration of interconnected system-level processes leads to a clearer

  10. Analytic evaluation of the weighting functions for remote sensing of blackbody planetary atmospheres : the case of limb viewing geometry

    NASA Technical Reports Server (NTRS)

    Ustinov, Eugene A.

    2006-01-01

    In a recent publication (Ustinov, 2002), we proposed an analytic approach to evaluation of radiative and geophysical weighting functions for remote sensing of a blackbody planetary atmosphere, based on general linearization approach applied to the case of nadir viewing geometry. In this presentation, the general linearization approach is applied to the limb viewing geometry. The expressions, similar to those obtained in (Ustinov, 2002), are obtained for weighting functions with respect to the distance along the line of sight. Further on, these expressions are converted to the expressions for weighting functions with respect to the vertical coordinate in the atmosphere. Finally, the numerical representation of weighting functions in the form of matrices of partial derivatives of grid limb radiances with respect to the grid values of atmospheric parameters is used for a convolution with the finite field of view of the instrument.

  11. Studying Weather and Climate Using Atmospheric Retrospective Analyses

    NASA Astrophysics Data System (ADS)

    Bosilovich, M. G.

    2014-12-01

    Over the last 35 years, tremendous amounts of satellite observations of the Earth's atmosphere have been collected along side the much longer and diverse record of in situ measurements. The satellite data records have disparate qualities, structure and uncertainty which make comparing weather from the 80s and 2000s a challenging prospect. Likewise, in-situ data records lack complete coverage of the earth in both space and time. Atmospheric reanalyses use the observations with numerical models and data assimilation to produce continuous and consistent weather data records for periods longer than decades. The result is a simplified data format with a relatively straightforward learning curve that includes many more variables available (through the modeling component of the system), but driven by a full suite of observational data. The simplified data format allows introduction into weather and climate data analysis. Some examples are provided from undergraduate meteorology program internship projects. We will present the students progression through the projects from their initial understanding and competencies to some final results and the skills learned along the way. Reanalyses are a leading research tool in weather and climate, but can also provide an introductory experience as well, allowing students to develop an understanding of the physical system while learning basic programming and analysis skills.

  12. Brick handling: a case study.

    PubMed

    Webb, R D; Handyside, J

    1982-09-01

    A small change in brick dimensions resulted in an increase in the perceived work-load of men loading and unloading pallets of bricks by hand. A laboratory study indicated that the change in brick dimensions required changes in grip pattern in order to unload bricks at the same rate, moving the same number at a time. These changed grip patterns resulted in increased upper body movement, increased chest-muscle activity and higher heart rates. These differences were reflected in higher subjective ratings of fatigue. PMID:15676442

  13. A numerical study of atmospheric Kàrmàn vortex shedding from Jeju Island

    NASA Astrophysics Data System (ADS)

    Ito, J.; Niino, H.

    2014-12-01

    Kàrmàn vortex shading universally occurs when a uniform flow pasts a bluff body. Similar vortex shading occurs when an atmospheric flow hits an isolated mountain, and can be seen in satellite images when the vortices are accompanied by clouds. While previous idealized numerical studies have focused on the mechanism of the atmospheric Kàrmàn vortex shading, there has been no simulation for a real case. In this study, a meso-scale non-hydrostatic model developed by the Japan Meteorological Agency (JMA) is used to reproduce the observed Kàrmàn vortex shedding, where initial and boundary conditions are given by the meso-scale objective analysis data of the JMA. The cases investigated here occurred on 16 and 20 February 2013 when satellite images clearly capture Kàrmàn vortex shading behind the Jeju Island over the East China sea. The size of simulation's domain is about 800 km by 1200 km in the horizontal direction, and the Jeju Island locates the center of the domain. The horizontal gird interval is 2 km. The cloud microphysics including the ice phase is considered. The numerical simulation successfully reproduced realistic Kàrmàn vortex shading which accompany characteristic clouds in the wake of the Jeju Island (see Figure; shading show mixing ratio of cloud water). The size of the vortices and there intervals appear to be comparable to those observed by the satellite. The winter monsoon flows out from Eurasia continent over the Yellow sea, which is 10 K warmer than the atmosphere, obtain much sensible and latent heat flux, and then a convective boundary layer is developed. Necessary conditions to form lee vortices proposed in previous studies are indeed satisfied: (1) the height of the convective boundary layer is lower than that of the mountain, and (2) the Froude number above the convective boundary layer is less than 0.4. The environment around the region in the wintertime is favorable for forming Kàrmàn vortex shading. The pressure depressions

  14. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

    SciTech Connect

    Hopke, P.K.

    1992-07-01

    This report describes studies on the chemical and physical behavior of the [sup 218]Po atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity in the sub-10 nm size range result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and its dose to the cells in the respiratory tract are to be fully assessed. The specific tasks of the controlled laboratory studies are to determine the formation rates of [center dot]OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO[sub 2] ethylene, and H[sub 2]S to lower vapor pressure compounds and determine the role of gas phase additives such as H[sub 2]O and NH[sub 3] in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of [sup 218]Po[sub x][sup +] in O[sub 2] at low radon concentrations. Tasks of the exposure studies in occupied indoor spaces are to initiate measurements of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants, to initiate a prospective study of the utility of measurement of deposited [sup 210]Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon, and to develop the methodology to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  15. Kinetic Monte Carlo models for the study of chemical reactions in the Earth's upper atmosphere

    NASA Astrophysics Data System (ADS)

    Turchak, L. I.; Shematovich, V. I.

    2016-06-01

    A stochastic approach to study the non-equilibrium chemistry in the Earth's upper atmosphere is presented, which has been developed over a number of years. Kinetic Monte Carlo models based on this approach are an effective tool for investigating the role of suprathermal particles both in local variations of the atmospheric chemical composition and in the formation of the hot planetary corona.

  16. The Center for the Study of Terrestrial and Extraterrestrial Atmospheres (CSTEA)

    NASA Technical Reports Server (NTRS)

    Thorpe, Arthur N.; Morris, Vernon R.

    1997-01-01

    The Center for the Study of Terrestrial and Extraterrestrial Atmospheres (CSTEA) was established in 1992. The center began with 14 active Principal Investigators (PI's). The research of the Center's PIs has, for the most part, continued in the same four areas as presented in the original proposal: Remote Sensing, Atmospheric Chemistry, Sensors and Detectors, and Spacecraft Dynamics.

  17. A comparative study of Venus and Mars - Upper atmospheres, ionospheres and solar wind interactions

    NASA Technical Reports Server (NTRS)

    Mahajan, K. K.; Kar, J.

    1990-01-01

    The neutral atmospheres of Mars and Venus are discussed. A comparative study is presented of the upper atmospheres, ionospheres, and solar wind interactions of these two planets. The review is mainly concerned with the region about 100 km above the surface of the planets.

  18. Case Studies on Educational Administration. Third Edition.

    ERIC Educational Resources Information Center

    Kowalski, Theodore J.

    This book contains 24 case studies selected to demonstrate the different types of challenges in contemporary educational leadership. It is intended to help prospective administrators develop decision-making skills. The cases are quite complex with multiple viewpoints and aspects. They represent a range of problems encountered by practitioners in…

  19. Case Studies of Environmental Risks to Children.

    ERIC Educational Resources Information Center

    Goldman, Lynn R.

    1995-01-01

    Presents case studies on children's exposure to pesticides, including risks through the use of the insecticide aldicarb on bananas, the home use of diazinon, and the use of interior house paint containing mercury. These cases illustrate how regulatory agencies, parents, health-care providers, and others who come into contact with children have…

  20. Case Studies in Elementary and Secondary Curriculum

    ERIC Educational Resources Information Center

    Boboc, Marius; Nordgren, R. D.

    2010-01-01

    Practical and engaging, this book contains 21 case studies that help students apply curriculum theory to classroom reality. Each case is authored by an in-service teacher, reflecting on ways to improve instruction by making changes to various aspects of the curriculum. These real-life examples investigate up-to-date curricular issues ranging from…

  1. Abbreviated Case Studies in Organizational Communication

    ERIC Educational Resources Information Center

    Wanguri, Deloris McGee

    2005-01-01

    The cases contained within organizational communication texts are generally two to three pages, often followed by questions. These case studies are certainly useful. They generally describe events in the present, provide some type of organizational context, include first-hand data, include a record of what people say and think, develop a…

  2. Case Study Report #8. Lisa Williams.

    ERIC Educational Resources Information Center

    Myers, Douglas D.; And Others

    This document presents one in a series of twenty-three case studies derived from in-depth interviews using a sampling of former participants in the Mountain-Plains program, a residential, family-based education program developed to improve the economic potential and lifestyle of selected student families in a six-state area. Each case study…

  3. Using radiative transfer models to study the atmospheric water vapor content and to eliminate telluric lines from high-resolution optical spectra

    NASA Astrophysics Data System (ADS)

    Gardini, A.; Maíz Apellániz, J.; Pérez, E.; Quesada, J. A.; Funke, B.

    2013-05-01

    The Radiative Transfer Model (RTM) and the retrieval algorithm, incorporated in the SCIATRAN 2.2 software package developed at the Institute of Remote Sensing/Institute of Enviromental Physics of Bremen University (Germany), allows to simulate, among other things, radiance/irradiance spectra in the 2400--24 000 Å range. In this work we present applications of RTM to two case studies. In the first case the RTM was used to simulate direct solar irradiance spectra, with different water vapor amounts, for the study of the water vapor content in the atmosphere above Sierra Nevada Observatory. Simulated spectra were compared with those measured with a spectrometer operating in the 8000--10 000 Å range. In the second case the RTM was used to generate telluric model spectra to subtract the atmospheric contribution and correct high-resolution stellar spectra from atmospheric water vapor and oxygen lines. The results of both studies are discussed.

  4. A Singapore Case of Lesson Study

    ERIC Educational Resources Information Center

    Cheng, Lu Pien; Yee, Lee Peng

    2012-01-01

    In this article, we present a case study of six Singaporean elementary school teachers working in a Lesson Study team that prepared them for problem solving instruction. The Lesson Study process included preparing, observing, and critiquing mathematics lessons in the context of solving fractions tasks. By conducting Lesson Study, we anticipated…

  5. A compilation of studies from Atmospheric Variability Experiment (AVE)

    NASA Technical Reports Server (NTRS)

    Scoggins, J. R.; Fuelberg, H. E.; Carlson, R. D.; Phelps, R. W.; Bellue, D. G.

    1973-01-01

    Five methods for obtaining the sign of vertical motion at various levels in the atmosphere were investigated to determine which gave the best explanation for areas of rain and no-rain in the southeastern United States during the period February 19-22, 1964. The methods used were the terrain-induced vertical motion, the kinematic method including the terrain effect, the adiabatic method, the omega equation, and the vorticity equation combined with Dines' Compensation Principle. Stability and moisture availability were considered but not as extensively as vertical motion. Values of vertical motion obtained by the kinetic method, including orographic lifting produced the best agreement with the observed areas. When terms in the omega equation were added through use of constant multipliers, results comparable to the adiabatic method were obtained. Without this addition large uncertainties occurred. Maps showing areas where terms of the omega equation would indicate positive vertical motion did not correlate well with the observed rainfall patterns.

  6. Theoretical studies of the physics of the solar atmosphere

    NASA Technical Reports Server (NTRS)

    Hollweg, Joseph V.

    1992-01-01

    Significant advances in our theoretical basis for understanding several physical processes related to dynamical phenomena on the sun were achieved. We have advanced a new model for spicules and fibrils. We have provided a simple physical view of resonance absorption of MHD surface waves; this allowed an approximate mathematical procedure for obtaining a wealth of new analytical results which we applied to coronal heating and p-mode absorption at magnetic regions. We provided the first comprehensive models for the heating and acceleration of the transition region, corona, and solar wind. We provided a new view of viscosity under coronal conditions. We provided new insights into Alfven wave propagation in the solar atmosphere. And recently we have begun work in a new direction: parametric instabilities of Alfven waves.

  7. Influence of atmospheric turbulence on optical measurement: a case report and review of literature

    NASA Astrophysics Data System (ADS)

    Yao, Linshen; Shang, Yang; Fu, Dan

    2016-01-01

    When videogammetry (optical measurement) was carried outdoor or under cruel indoor circumstance, the results would be inevitably affected by the atmosphere turbulence. As a result, the precision of surveying was destroyed. The field of air turbulence's impact on optical measurement was neglected by scholars for a long time, the achievements massed about laser optics and optical communications. The mostly adapted method was noise filtration when the pixel wandering could not be rejected in engineering application, which got little improvement on usual conditions. The principle of influence under atmospheric turbulence on optical measurement is presented in this paper. And experiments data and applications are carried out to announce the impact of atmospheric turbulence. Combining with relevant researches, some essential issues and expectations of the atmospheric turbulence research are proposed.

  8. BTS Case Study: The Galloway Family Home

    SciTech Connect

    Brandegee Group

    1999-03-08

    Case study of an energy-efficient Habitat for Humanity house that uses 30% less energy than conventional residential construction. The project was part of the Jimmy Carter Work Project in rural Appalachia in 1997.

  9. Multispectral Resource Sampler (MRS): Proof of concept study on atmospheric corrections. Determinations of atmospheric optical parameters using the multispectral resource sampler atmospheric optical

    NASA Technical Reports Server (NTRS)

    Turner, R. E.

    1979-01-01

    An investigation was performed to determine which mathematical algorithms should be used in the calculation of atmospheric optical parameters using the Multispectral Resource Sampler (MRS) sensor. A simulation of the MRS sensor was performed using a radiative-transfer model. The simulation provides the spectral radiance at the satellite sensor in terms of various atmospheric parameters, such as optical thickness, solar zenith angle, nadir view angle, relative azimuth angle, bi-directional reflectance of the target, background albedo, and wavelength. Atmospheric correction algorithms were also developed for the determination of the total spectral optical thickness of the atmosphere for: (1) homogeneous (horizontal) hazy atmospheres with diffuse targets; (2) inhomogeneous (horizontal) hazy atmospheres with diffuse targets; and (3) homogeneous (horizontal) hazy atmospheres with non-diffuse targets.

  10. An observational study of the response of the upper atmosphere of Mars to lower atmospheric dust storms

    NASA Astrophysics Data System (ADS)

    Withers, Paul; Pratt, R.

    2013-07-01

    The effects of dust storms on densities, temperatures, and winds in the lower atmosphere of Mars are substantial. Here we use upper atmospheric observations to investigate how dust storms affect the upper atmosphere of Mars. We use aerobraking accelerometer, ultraviolet stellar occultation, and radio occultation datasets to examine the magnitudes and timescales associated with upper atmospheric density changes during dust storms. We find that: (1) Upper atmospheric conditions can be perturbed by dust storms outside the classical "dust storm season" of Ls = 180-360°. (2) The upper atmospheric regions affected by even a small dust event can include nearly all latitudes. (3) Atmospheric temperatures can be affected by dust storms at altitudes as high as 160 km. (4) The onset of the upper atmospheric response to a distant dust event can be a few days or less. (5) The characteristic timescale for the decay of the upper atmospheric response to a dust event can be 20-120° of Ls, and it may differ from the corresponding timescale for the lower atmosphere. (6) Average upper atmospheric densities can change by factors of a few during mere regional dust storms and an order of magnitude change is possible for the largest storms: these are general trends and individual density measurements may be greater than suggested by a general trend by a factor of two due to the intrinsic variability of the upper atmosphere. The decay timescale and magnitude of the upper atmospheric response depend on altitude, and larger events have shorter decay timescales. The substantial effects seen in the upper atmosphere illuminate the vertical extent of modified atmospheric circulation patterns and associated adiabatic heating/cooling during extreme dust loading, timescales for the onset and decay of the upper atmospheric response, and highlight potential dangers to spacecraft operations.

  11. Proposal on limits for chemical exposure in saturation divers' working atmosphere: the case of benzene.

    PubMed

    Djurhuus, Rune; Nossum, Vibeke; Øvrebø, Steinar; Skaug, Vidar

    2012-03-01

    Saturation diving is performed under extreme environmental conditions. The divers are confined to a limited space for several weeks under high environmental pressure and elevated oxygen partial pressure. At present, divers are protected against chemical exposure by standard exposure limits only adjusted for the increased exposure length, i.e. from 8 to 24 hours a day and from 5 to 7 days a week. The objective of the present study was to indicate a procedure for derivation of occupational exposure limits for saturation diving, termed hyperbaric exposure limits (HEL). Using benzene as an example, a procedure is described that includes identification of the latest key documents, extensive literature search with defined exclusion criteria for the literature retrieved. Hematotoxicity and leukemia were defined as the critical effects, and exposure limits based upon concentration and cumulative exposure data and corresponding risks of leukemia were calculated. Possible interactions of high pressure, elevated pO₂, and continuous exposure have been assessed, and incorporated in a final suggestion of a HEL for benzene. The procedure should be applicable for other relevant chemicals in the divers' breathing atmosphere. It is emphasized that the lack of interactions from pressure and oxygen indicated for benzene may be completely different for other chemicals. PMID:22304480

  12. Recent advances on the study of land-atmospheric interaction on the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ma, Y.

    2009-04-01

    As a unique geological and geographical unit, the Tibetan Plateau dramatically impacts the world's environment and especially controls climatic and environmental changes in China, Asia and even in the Northern Hemisphere. Tibetan Plateau, therefore, provides a field laboratory for studying global change. With support from various agencies in the People's Republic of China, a Tibetan Observation and Research Platform (TORP) is now implementing. Firstly the background of the establishment of the TORP, the establishing and monitoring plan of long-term scale (5-10 years) of the TORP has been introduced. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes and CO2 flux partitioning (diurnal variation, inter-monthly variation and vertical variation etc), the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this paper. The study on the regional distribution of land surface heat fluxes of paramount importance over heterogeneous landscape of the Tibetan Plateau. Therefore, here the parameterization methods based on satellite data (NOAA/AVHRR, Landsat-7 ETM, ASTER and MODIS) and Atmospheric Boundary Layer (ABL) observations have been proposed and tested for deriving surface reflectance, surface temperature, NDVI, MSAVI, vegetation coverage, LAI, net radiation flux, soil heat flux, sensible heat flux and latent heat flux over heterogeneous landscape. As cases study, the methods were applied to the experimental area of the CAMP/Tibet (CEOP (Coordinated Enhanced Observing Period) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau), which located at the central Tibetan Plateau and the whole Tibetan Plateau area. Five scenes of Landsat-7 ETM data, four scenes of NOAA/AVHRR data, three scenes of ASTER data and four MODIS data were used in this study. To validate the proposed methods, the ground

  13. A Case Study about Communication Strategies

    ERIC Educational Resources Information Center

    Lin, Grace Hui Chin

    2011-01-01

    The primary purpose of this case study was to identify what were Taiwanese University English as a Foreign Language (EFL) learners' perceptions about learning communication strategies. This study collected qualitative data about students' beliefs and attitudes as they learned communication strategies. The research question guiding the study was:…

  14. Education and Work Councils: Four Case Studies.

    ERIC Educational Resources Information Center

    Prager, Audrey; And Others

    This collection of four case studies represents the conclusion of a two-phase study of a federal program to sponsor education and work councils. Following an outline of the history and concept of education and work councils as well as the findings of a study of such councils, the importance of council collaboration with selected sectors is…

  15. Predicting Students Drop Out: A Case Study

    ERIC Educational Resources Information Center

    Dekker, Gerben W.; Pechenizkiy, Mykola; Vleeshouwers, Jan M.

    2009-01-01

    The monitoring and support of university freshmen is considered very important at many educational institutions. In this paper we describe the results of the educational data mining case study aimed at predicting the Electrical Engineering (EE) students drop out after the first semester of their studies or even before they enter the study program…

  16. Atmospheric temperature changes by volcanic eruptions: GPS radio occultation observations in the 2010 Icelandic and 2011 Chilean cases

    NASA Astrophysics Data System (ADS)

    Okazaki, Ikuya; Heki, Kosuke

    2012-11-01

    Volcanic plumes modify atmospheric temperatures. Wang et al. (2009) reported localized temperature changes associated with the Mt Chaiten eruption in May 2008 using the deviation of GPS radio occultation temperature data from the NCEP global forecast system model. On 14 April 2010, a large scale eruption started under the glacier Eyjafjallajökull in Southern Iceland, and Puyehue-Cordón Caulle (Puyehue), in Chile, started eruption on 4 June, 2011. Here we study instantaneous and localized temperature changes with these two eruptions following the method of Wang et al. (2009). Post-eruption negative temperature anomalies at the 250 hPa plane were clearly observed in the Eyjafjallajökull eruption. In the Puyehue eruption, however, such anomalies were not so clear due possibly to insufficient accuracy of the forecast model. By comparing the temperature profiles in the downwind areas of the two eruptions, we found that significant temperature decreases occurred at ~ 10.5 and ~ 11.5 km altitude in the Eyjafjallajökull and the Puyehue cases, respectively. These results generally agree with Wang et al. (2009), but post-eruption temperature changes seem to be influenced by additional factors, e.g. volcanic explosivity and local climatology.

  17. A Solar Radiation Parameterization for Atmospheric Studies. Volume 15

    NASA Technical Reports Server (NTRS)

    Chou, Ming-Dah; Suarez, Max J. (Editor)

    1999-01-01

    The solar radiation parameterization (CLIRAD-SW) developed at the Goddard Climate and Radiation Branch for application to atmospheric models are described. It includes the absorption by water vapor, O3, O2, CO2, clouds, and aerosols and the scattering by clouds, aerosols, and gases. Depending upon the nature of absorption, different approaches are applied to different absorbers. In the ultraviolet and visible regions, the spectrum is divided into 8 bands, and single O3 absorption coefficient and Rayleigh scattering coefficient are used for each band. In the infrared, the spectrum is divided into 3 bands, and the k-distribution method is applied for water vapor absorption. The flux reduction due to O2 is derived from a simple function, while the flux reduction due to CO2 is derived from precomputed tables. Cloud single-scattering properties are parameterized, separately for liquid drops and ice, as functions of water amount and effective particle size. A maximum-random approximation is adopted for the overlapping of clouds at different heights. Fluxes are computed using the Delta-Eddington approximation.

  18. Theoretical studies of the solar atmosphere and interstellar pickup ions

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Solar atmosphere research activities are summarized. Specific topics addressed include: (1) coronal mass ejections and related phenomena; (2) parametric instabilities of Alfven waves; (3) pickup ions in the solar wind; and (4) cosmic rays in the outer heliosphere. Also included is a list of publications covering the following topics: catastrophic evolution of a force-free flux rope; maximum energy release in flux-rope models of eruptive flares; sheet approximations in models of eruptive flares; material ejection, motions of loops and ribbons of two-ribbon flares; dispersion relations for parametric instabilities of parallel-propagating; parametric instabilities of parallel-propagating Alfven waves; beat, modulation, and decay instabilities of a circularly-polarized Alfven wave; effects of time-dependent photoionization on interstellar pickup helium; observation of waves generated by the solar wind pickup of interstellar hydrogen ions; ion thermalization and wave excitation downstream of the quasi-perpendicular bowshock; ion cyclotron instability and the inverse correlation between proton anisotrophy and proton beta; and effects of cosmic rays and interstellar gas on the dynamics of a wind.

  19. Study of atmospheric muons using a cosmic ray telescope

    NASA Astrophysics Data System (ADS)

    Abdollahi, S.; Bahmanabadi, M.; Purmohammad, D.

    2013-02-01

    The charge ratio of cosmic muons holds important information for both the atmospheric neutrino anomaly and hadronic interaction models. In this paper we measured the muon charge ratio (R_{\\mu }=N_{\\mu ^{+}}/N_{\\mu ^{-}}) in the cosmic ray flux in the momenta range 0.76-1.60 GeV/c by using a cosmic ray telescope. The delayed coincidence method is used based on the reduced mean lifetime of negative muons due to nuclear capture in matter. The systematic time-dependent effects of the muon charge ratio are considered by grouping the decay data into different time intervals. We compared the experimental data with the predictions of CORSIKA simulations using a high energy interaction model (QGSJET-II) and two low energy interaction models (UrQMD and GHEISHA) in the energy range 1011-1016 eV for primary particles. In addition, by considering the muon flux in different zenithal and azimuthal angles, the muon angular distribution is obtained as I(θ) = I(0)cos nθ with average n = 1.91 ± 0.07. Dependence of the muon flux on the azimuth angle (the East-West effect) is also observed, due to the influence of the geomagnetic field in particular on low energy muons.

  20. Feasibility study: Atmospheric general circulation experiment, volume 1

    NASA Technical Reports Server (NTRS)

    Homsey, R. J. (Editor)

    1981-01-01

    The atmospheric general circulation experiment (AGCE) uses a rotating fluid flow cell assembly. The key technical areas affecting the feasibility of the design and operation of the AGCE are investigated. The areas investigated include materials for the flow cell assembly, thermal design, high voltage power supply design, effective retrieval and handling of experiment data and apparatus configuration. Several materials, DMSO and m-tolunitrile, were selected as candidate fluids for the flow cell principally for their high dielectric constant which permits the high voltage power supply design to be held to 15 kV and still simulate terrestrial gravity. Achievement of a low dissipation factor in the fluid to minimize internal heating from the applied electrical field depends strongly on purification and handling procedures. The use of sapphire as the outer hemisphere for the flow cell provides excellent viewing conditions without a significant impact on attaining the desired thermal gradients. Birefringent effects from sapphire can be held to acceptably low limits. Visualization of flow fluid is achieved through the motion of a dot matrix formed by photochromic dyes. Two dyes found compatible with the candidate fluids are spiropyran and triarylmethane. The observation of the dot motion is accomplished using a flying spot scanner.

  1. A Study of the Effects of Atmospheric Phenomena on Mars Science Laboratory Entry Performance

    NASA Technical Reports Server (NTRS)

    Cianciolo, Alicia D.; Way, David W.; Powell, Richard W.

    2008-01-01

    At Earth during entry the shuttle has experienced what has come to be known as potholes in the sky or regions of the atmosphere where the density changes suddenly. Because of the small data set of atmospheric information where the Mars Science Laboratory (MSL) parachute deploys, the purpose of this study is to examine the effect similar atmospheric pothole characteristics, should they exist at Mars, would have on MSL entry performance. The study considers the sensitivity of entry design metrics, including altitude and range error at parachute deploy and propellant use, to pothole like density and wind phenomena.

  2. Atmospheric mercury deposition to Lake Michigan during the Lake Michigan Mass Balance Study.

    PubMed

    Landis, Matthew S; Keeler, Gerald J

    2002-11-01

    Wet and dry mercury (Hg) deposition were calculated to Lake Michigan using a hybrid receptor modeling framework. The model utilized mercury monitoring data collected during the Lake Michigan Mass Balance Study and the Atmospheric Exchange Over Lakes and Oceans Studytogether with high-resolution over-water meteorological date provided by the National Oceanic and Atmospheric Administration (July, 1994-October, 1995). Atmospheric deposition was determined to be the primary pathway for mercury inputto Lake Michigan, contributing approximately 84% of the estimated 1403 kg total annual input (atmospheric deposition + tributary input). Wet (10.6 microg m(-2)) and dry deposition (9.7 microg m(-2)) contributed almost equally to the annual atmospheric Hg deposition of 20.3 microg m(-2) (1173 kg). Re-emission of dissolved gaseous Hg from the lake was also significant (7.8 microg m(-2)), reducing the net atmospheric deposition to 12.5 microg m(-2) (720 kg). A strong urban influence was observed in the over-water mercury deposition estimates in the southern portion of the lake. The Chicago/Gary urban area was estimated to contribute approximately 20% (127 kg) of the annual atmospheric mercury deposition to Lake Michigan. The magnitude of local anthropogenic mercury sources in the Chicago/Gary urban area suggests that emission reductions could significantly reduce atmospheric mercury deposition into Lake Michigan. PMID:12433159

  3. The broadening of the calcium resonance line in a high-temperature helium atmosphere. [solar and white dwarf atmospheric studies

    NASA Technical Reports Server (NTRS)

    Driver, R. D.; Snider, J. L.

    1976-01-01

    The paper describes experimental measurements of the shape of the Ca I resonance line at 4227 A in a high-temperature helium atmosphere. A ballistic piston compressor was used to produce hot helium in the temperature range from 3000 to 7000 K and the number-density range from 2 to 4 by 10 to the 20th power per cu cm, which conditions approximate those postulated for the atmospheres of certain cool white-dwarf stars. The Boltzmann temperature of the calcium atoms was measured by the brightness-emissivity method, the absorption line shape was measured with a twelve-channel polychromator, and the helium kinetic temperature was calculated from the equation of an ideal gas. The observed deviation from thermodynamic equilibrium is illustrated. The value of the ratio of the damping constant to the helium number density at 5000 K is found to be 45 (+ or - 4) by 10 to the -22nd power A cu cm, or 4.7 (+ or - 0.4) by 10 to the -9th power rad/s cu cm. It is noted that no existing line-broadening calculation for the calcium-helium system is consistent with the present results. Recent studies of the 4227-A line in spectra of the sun and the white dwarf van Maanen 2 are discussed.

  4. INTERCOMPARISON STUDY OF ATMOSPHERIC MERCURY MODELS: 1. COMPARISON OF MODELS WITH SHORT-TERM MEASUREMENTS

    EPA Science Inventory

    Five regional scale models with a horizontal domain covering the European continent and its surrounding seas, one hemispheric and one global scale model participated in an atmospheric mercury modelling intercomparison study. Model-predicted concentrations in ambient air were comp...

  5. Concordia Multi-Process Atmospheric Studies (CoMPASs): study of the vertical structure of the Antarctic atmosphere with a synergy of different remote sensing techniques

    NASA Astrophysics Data System (ADS)

    Bianchini, Giovanni; Argenitini, Stefania; Baldi, Massimo; Cairo, Francesco; Calzolari, Francescopiero; Casasanta, Giampietro; Conidi, Alessandro; Del Guasta, Massimo; Di Natale, Gianluca; Federico, Stefano; Lupi, Angelo; Mazzola, Mauro; De Muro, Mauro; Palchetti, Luca; Petenko, Igor; Petkov, Boyan; Snels, Marcel; Trivellone, Giuliano; Viola, Angelo; Viterbini, Maurizio

    2014-05-01

    Concordia station, in the Dome C region, Antarctica, is the ideal site for the study of micro-physical, meteorological and chemical processes in unperturbed and extreme conditions: the relative absence of perturbations at the mesoscale allows highly representative observations of the atmosphere inside of the polar vortex, as well as the possibility of studying the micro-meteorological "asymptotic" conditions in the boundary layer. Given these privileged conditions, the interaction between the different processes will be especially noticeable. The CoMPASs (Concordia Multi-Process Atmospheric Studies) project has been developed in order to identify and characterize these feedbacks and interactions between processes, spanning across three different atmospheric regions: the boundary layer, the troposphere and the stratosphere. The main research themes follow the vertical structure of the atmosphere: - Characterization of the atmospheric boundary layer (ABL) in terms of dynamics, turbulence and radiation, especially during the winter period, in which the ABL has peculiar properties in terms of reduced thickness and extreme sensitivity to external forcing. - Study of the clouds in the free troposphere, which, in the region of Dome C, shows a remarkable variability, both daily and seasonal, and therefore requires continuous monitoring to quantify its interactions with the neighbouring atmospheric layers. - Study of the stratospheric processes within the Antarctic polar vortex, as ozone chemistry and polar stratospheric clouds, carried out throughout the year in order to constantly follow the evolution of the vortex itself. CoMPASs makes use of a strong observational component, deploying an array of different instruments all characterized by the vertical remote sensing measurement technique: stratospheric and tropospheric lidars, UV and middle/far-infrared spectroradiometers, and a high-resolution mini-sodar. The turbulence in the surface layer will be monitored with fast

  6. The major influence of the atmosphere on intracranial pressure: an observational study

    NASA Astrophysics Data System (ADS)

    Herbowski, Leszek

    2016-06-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  7. Gigantic Suprapubic Lymphedema: A Case Study

    PubMed Central

    Tanhaeivash, Roozbeh; Franiel, Tobias; Grimm, Marc-Oliver

    2016-01-01

    We present the first case study of idiopathic gigantic suprapubic lymphedema and buried penis treated with puboscrotal reconstruction in a patient with initial extreme obesity after an extensive weight reduction (120 kg). Massive localized lymphedema of the suprapubic region should be differentiated from the scrotal type. Severe lymphedema could not resolve on its own and weight reduction does not seem to be helpful in such cases. PMID:27574599

  8. Gigantic Suprapubic Lymphedema: A Case Study.

    PubMed

    Tanhaeivash, Roozbeh; Franiel, Tobias; Grimm, Marc-Oliver; Horstmann, Marcus

    2016-08-01

    We present the first case study of idiopathic gigantic suprapubic lymphedema and buried penis treated with puboscrotal reconstruction in a patient with initial extreme obesity after an extensive weight reduction (120 kg). Massive localized lymphedema of the suprapubic region should be differentiated from the scrotal type. Severe lymphedema could not resolve on its own and weight reduction does not seem to be helpful in such cases. PMID:27574599

  9. Nuclear forensic investigations: two case studies.

    PubMed

    Wallenius, M; Mayer, K; Ray, I

    2006-01-01

    This paper describes the methodology and analytical methods used in nuclear forensic investigations. Two case studies are taken as examples to illustrate this. These examples represent typical cases that have been analysed at the Institute for Transuranium Elements (ITU) since last 10 years, i.e. the beginning of the illicit trafficking of nuclear materials. Results of the various analytical techniques are shown, which, together with other type of information, reveal the origin of the material. PMID:16410154

  10. Weather Features Associated with Aircraft Icing Conditions: A Case Study

    PubMed Central

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk. PMID:24701152

  11. Weather features associated with aircraft icing conditions: a case study.

    PubMed

    Fernández-González, Sergio; Sánchez, José Luis; Gascón, Estíbaliz; López, Laura; García-Ortega, Eduardo; Merino, Andrés

    2014-01-01

    In the context of aviation weather hazards, the study of aircraft icing is very important because of several accidents attributed to it over recent decades. On February 1, 2012, an unusual meteorological situation caused severe icing of a C-212-200, an aircraft used during winter 2011-2012 to study winter cloud systems in the Guadarrama Mountains of the central Iberian Peninsula. Observations in this case were from a MP-3000A microwave radiometric profiler, which acquired atmospheric temperature and humidity profiles continuously every 2.5 minutes. A Cloud Aerosol and Precipitation Spectrometer (CAPS) was also used to study cloud hydrometeors. Finally, ice nuclei concentration was measured in an isothermal cloud chamber, with the goal of calculating concentrations in the study area. Synoptic and mesoscale meteorological conditions were analysed using the Weather Research and Forecasting (WRF) model. It was demonstrated that topography influenced generation of a mesolow and gravity waves on the lee side of the orographic barrier, in the region where the aircraft experienced icing. Other factors such as moisture, wind direction, temperature, atmospheric stability, and wind shear were decisive in the appearance of icing. This study indicates that icing conditions may arise locally, even when the synoptic situation does not indicate any risk. PMID:24701152

  12. Science/Society Case Study - Ozone

    ERIC Educational Resources Information Center

    Moore, John W., Ed.; Moore, Elizabeth A., Ed.

    1975-01-01

    Describes various threats to the stability of the ozone layer of the atmosphere, including freons emitted from aerosol cans, combustion products from jet aircraft engines, and nuclear explosions in the atmosphere. (MLH)

  13. Social Studies Project Evaluation: Case Study and Recommendations.

    ERIC Educational Resources Information Center

    Napier, John

    1982-01-01

    Describes the development and application of a model for social studies program evaluations. A case study showing how the model's three-step process was used to evaluate the Improving Citizenship Education Project in Fulton County, Georgia is included. (AM)

  14. Technologies in Literacy Learning: A Case Study

    ERIC Educational Resources Information Center

    Cloonan, Anne

    2010-01-01

    This article draws on outcomes of a study which explored changes in teachers' literacy pedagogies as a result of their participation in a collaborative teacher professional learning project. The educational usability of schemas drawn from multiliteracies and Learning by Design theory is illustrated through a case study of a teacher's work on…

  15. Collaborative Assessment: Middle School Case Study

    ERIC Educational Resources Information Center

    Parkison, Paul T.

    2014-01-01

    Utilizing a participant observer research model, a case study of the efficacy of a collaborative assessment methodology within a middle school social studies class was conducted. A review of existing research revealed that students' perceptions of assessment, evaluation, and accountability influence their intrinsic motivation to learn. A…

  16. Case Studies of the Migrant Education Program.

    ERIC Educational Resources Information Center

    Marks, Ellen L.

    Intended for federal policymakers, this study examined four aspects of the Chapter 1 migrant education program: program administration, program services, students served, and program expenditures. Case studies were conducted in California, Florida, Illinois, Massachusetts, Oregon, and Texas between November 1986 and March 1987. State agencies and…

  17. Case Studies in Australian Adult Education.

    ERIC Educational Resources Information Center

    Clark, Ralph J., Ed.; Rooth, S. John, Ed.

    This publication contains the following 24 case studies of adult education in Australia: "NSW Department of Agriculture Home Study Programme" (O'Neill); "Self-Help Adult Education: The University of the Third Age at the Brisbane CAE" (Swindell); "Marriage Enrichment Programme" (D. Kerr, C. Kerr); "Carringbush Library: A Place to Be" (Letcher);…

  18. A Multiple Case Study of Innovation

    ERIC Educational Resources Information Center

    Zheng, Wei; Khoury, Anne E.

    2008-01-01

    This study aims to explore how leadership and contextual factors influence innovation in R&D teams in national laboratories, using the approach of multiple case studies. This paper provides some preliminary findings from two highly innovative teams residing in two national laboratories in the US. The preliminary results suggested several common…

  19. Connecting Reading and Writing: A Case Study

    ERIC Educational Resources Information Center

    Li, Zhanfang

    2015-01-01

    Connecting reading and writing, proposed by many scholars, is realized in this case study. The 30 participants in this study are the English majors of the third year in one School of Foreign Languages in Beijing. They are encouraged to write journals every week, based on the source text materials in their Intensive Reading class, with the final…

  20. Anthropology and Popular Culture: A Case Study.

    ERIC Educational Resources Information Center

    Estes, Jack

    The study of popular culture in the United States is an appropriate anthropological endeavor, as evidenced in a case study of the volcanic eruption of Mt. St. Helens in Oregon. By examining its popular arts, anthropologists gain understanding of the culture and its people. For example, an analysis of reactions to the Mt. St. Helens eruption…

  1. CASE STUDY: DIELDRIN ATTACK IN DALYAN LAGOON

    EPA Science Inventory

    During the first two weeks of December 2005, NATO sponsored an Advanced Study Institute (ASI) in Istanbul, Turkey. Part of this ASI involved a case study of a terrorist attack, where a chemical was assumed to be dumped into Sulunger Lake in Turkey. This chapter documents the re...

  2. Case Studies of Three Interorganizational Arrangements.

    ERIC Educational Resources Information Center

    Yin, Robert K.; And Others

    As part of their study of interorganizational collaboration, researchers present three detailed case studies of how regional education agencies (REAs) supply knowledge utilization services to the school districts they serve. The three REAs are the Wayne County (Michigan) Intermediate School District (with 36 districts), the Educational Improvement…

  3. Surface Characterization for Land-Atmosphere Studies of CLASIC

    NASA Astrophysics Data System (ADS)

    Jackson, T. J.; Kustas, W.; Torn, M. S.; Meyers, T.; Prueger, J.; Fischer, M. L.; Avissar, R.; Yueh, S.; Anderson, M.; Miller, M.

    2006-12-01

    The Cloud and Land Surface Interaction Campaign will focus on interactions between the land surface, convective boundary layer, and cumulus clouds. It will take place in the Southern Great Plains (SGP) area of the U.S, specifically within the US DOE ARM Climate Research Facility. The intensive observing period will be June of 2007, which typically covers the winter wheat harvest in the region. This region has been the focus of several related experiments that include SGP97, SGP99, and SMEX03. For the land surface, some of the specific science questions include 1) how do spatial variations in land cover along this trajectory modulate the cloud structure and the low-level water vapor budget, 2) what are the relationships between land surface characteristics (i.e., soil texture, vegetation type and fractional cover) and states (particularly soil moisture and surface temperature) and the resulting impact of the surface energy balance on boundary layer and cloud structure and dynamics and aerosol loading; and 3) what is the interplay between cumulus cloud development and surface energy balance partitioning between latent and sensible heat, and implications for the carbon flux? Most of these objectives will require flux and state measurements throughout the dominant land covers and distributed over the geographic domain. These observations would allow determining the level of up- scaling/aggregation required in order to understand the impact of landscape changes affecting energy balance/flux partitioning and impact on cloud/atmospheric dynamics. Specific contributions that are planned to be added to CLASIC include continuous tower-based monitoring of surface fluxes for key land cover types prior to, during, and post-IOP, replicate towers to quantify flux variance within each land cover, boundary layer properties and fluxes from a helicopter-based system, airplane- and satellite-based flux products throughout the region, aircraft- and tower-based concentration data for

  4. Research relative to atmosphere physics and spacecraft applications studies

    NASA Technical Reports Server (NTRS)

    Greenwood, Stuart W.

    1987-01-01

    Progress is reported in several areas of research. Brief descriptions are given in each of the following areas: Spacelab data analysis; San Marco activity; Molecular physics; Stellar energy analysis; Troposphere data analysis; Voyager encounter analysis; Laser activity; Gravity wave study; Venus studies; and Shuttle environmental studies.

  5. A case study of air enrichment in rotary kiln incineration

    SciTech Connect

    Melo, G.F.; Lacava, P.T.; Carvalho, J.A. Jr.

    1998-07-01

    This paper presents a case study of air enrichment in an industrial rotary kiln type incineration unit. The study is based on mass and energy balances, considering the combustion reaction of a mixture composed by the residue and the auxiliary fuel with air enriched with oxygen. The steps are shown for the primary chamber (rotary kiln) and secondary chamber (afterburner). The residence times in the primary and secondary chamber are 2.0 and 3.2 sec, respectively. The pressure is atmospheric in both chambers. Based on constant chamber gas residence time and gas temperature, it is shown that the residue input rates can be increased by one order of magnitude as air is substituted by pure oxygen. As the residue consumption rate in the rotary kiln is also dependent on residue physical characteristics (mainly size), the study was also carried out for different percentages of oxygen in the oxidizer gas.

  6. Management of atmospheric pollutants from waste incineration processes: the case of Bozen.

    PubMed

    Ragazzi, Marco; Tirler, Werner; Angelucci, Giulio; Zardi, Dino; Rada, Elena Cristina

    2013-03-01

    This article presents the case study of a waste incinerator located in a region rich in natural and environmental resources, and close to the city of Bozen, where there are about 100,000 inhabitants. Local authorities paid special attention to the effect of the plant on human health and the surrounding environment. Indeed, among the measures adopted to control the emissions, in 2003 an automatic sampling system was installed specifically to monitor polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions during the complete operation time of the plant. The continuous sampling system was coupled directly to aerosol spectrometers for the determination of fine and ultra-fine particles in the emissions of the plant. The measurement results suggest that the waste incineration plant of Bozen is not a significant source of PCDD/F, or fine and ultra-fine particles. Immission measurements from other monitoring systems confirmed these results. PMID:23363737

  7. Measurements of trace constituents from atmospheric infrared emission and absorption spectra, a feasibility study

    NASA Technical Reports Server (NTRS)

    Goldman, A.; Williams, W. J.; Murcray, D. G.

    1974-01-01

    The feasibility of detecting eight trace constituents (CH4, HCl, HF, HNO3, NH3, NO, NO2 and SO2) against the rest of the atmospheric background at various altitudes from infrared emission and absorption atmospheric spectra was studied. Line-by-line calculations and observational data were used to establish features that can be observed in the atmospheric spectrum due to each trace constituent. Model calculations were made for experimental conditions which approximately represent state of the art emission and absorption spectrometers.

  8. Integrating ethics into case study assignments.

    PubMed

    Marshall, Pamela A

    2014-12-01

    I teach an upper-level writing course, Genes, Race, Gender, and Society, designed for Life Science majors, in which I utilize a case study to expose students to ethical ways of thinking. Students first work through the topical case study and then are challenged to rethink their responses through the lenses of ethics, taking into account different ethical frameworks. Students then develop their own case study, integrating ethical components. I want to expose my students to this way of thinking because I see technology being driven by the Jurassic Park phenomenon, "Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should," and want future physicians grounded in a sense of how their actions relate to the greater good. PMID:25574287

  9. Shuttle Case Study Collection Website Development

    NASA Technical Reports Server (NTRS)

    Ransom, Khadijah S.; Johnson, Grace K.

    2012-01-01

    As a continuation from summer 2012, the Shuttle Case Study Collection has been developed using lessons learned documented by NASA engineers, analysts, and contractors. Decades of information related to processing and launching the Space Shuttle is gathered into a single database to provide educators with an alternative means to teach real-world engineering processes. The goal is to provide additional engineering materials that enhance critical thinking, decision making, and problem solving skills. During this second phase of the project, the Shuttle Case Study Collection website was developed. Extensive HTML coding to link downloadable documents, videos, and images was required, as was training to learn NASA's Content Management System (CMS) for website design. As the final stage of the collection development, the website is designed to allow for distribution of information to the public as well as for case study report submissions from other educators online.

  10. Impact of AIRS Thermodynamic Profiles on Precipitation Forecasts for Atmospheric River Cases Affecting the Western United States

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley T.; Jedlovec, Gary J.; Blakenship, Clay B.; Wick, Gary A.; Neiman, Paul J.

    2013-01-01

    This project is a collaborative activity between the NASA Short-term Prediction Research and Transition (SPoRT) Center and the NOAA Hydrometeorology Testbed (HMT) to evaluate a SPoRT Advanced Infrared Sounding Radiometer (AIRS: Aumann et al. 2003) enhanced moisture analysis product. We test the impact of assimilating AIRS temperature and humidity profiles above clouds and in partly cloudy regions, using the three-dimensional variational Gridpoint Statistical Interpolation (GSI) data assimilation (DA) system (Developmental Testbed Center 2012) to produce a new analysis. Forecasts of the Weather Research and Forecasting (WRF) model initialized from the new analysis are compared to control forecasts without the additional AIRS data. We focus on some cases where atmospheric rivers caused heavy precipitation on the US West Coast. We verify the forecasts by comparison with dropsondes and the Cooperative Institute for Research in the Atmosphere (CIRA) Blended Total Precipitable Water product.

  11. Laboratory infrared studies of molecules of atmospheric and astrophysical interest

    NASA Technical Reports Server (NTRS)

    Rao, N. N.

    1982-01-01

    Nineteen reprints on the molecular species are compiled. Much of the work was done by using the Doppler-limited resolution provided by diode lasers. The diode laser was used as a source to a grating spectrometer which has been used earlier for high resolution studies. This technique provided many advantages. Wherever possible, the studies have been directed to intensity determinations of infrared bands.

  12. MEAD: an interdisciplinary study of the marine effects of atmospheric deposition in the Kattegat.

    PubMed

    Spokes, L; Jickells, T; Weston, K; Gustafsson, B G; Johnsson, M; Liljebladh, B; Conley, D; Ambelas-Skjødth, C; Brandt, J; Carstensen, J; Christiansen, T; Frohn, L; Geernaert, G; Hertel, O; Jensen, B; Lundsgaard, C; Markager, S; Martinsen, W; Møller, B; Pedersen, B; Sauerberg, K; Sørensen, L L; Hasager, C C; Sempreviva, A M; Pryor, S C; Lund, S W; Larsen, S; Tjernström, M; Svensson, G; Zagar, M

    2006-04-01

    This paper summarises the results of the EU funded MEAD project, an interdisciplinary study of the effects of atmospheric nitrogen deposition on the Kattegat Sea between Denmark and Sweden. The study considers emissions of reactive nitrogen gases, their transport, transformations, deposition and effects on algal growth together with management options to reduce these effects. We conclude that atmospheric deposition is an important source of fixed nitrogen to the region particularly in summer, when nitrogen is the limiting nutrient for phytoplankton growth, and contributes to the overall eutrophication pressures in this region. However, we also conclude that it is unlikely that atmospheric deposition can, on its own, induce algal blooms in this region. A reduction of atmospheric nitrogen loads to this region will require strategies to reduce emissions of ammonia from local agriculture and Europe wide reductions in nitrous oxide emissions. PMID:16271430

  13. NASA's upper atmosphere research satellite: A program to study global ozone change

    NASA Technical Reports Server (NTRS)

    Luther, Michael R.

    1992-01-01

    The Upper Atmosphere Research Satellite (UARS) is a major initiative in the NASA Office of Space Science and Applications, and is the prototype for NASA's Earth Observing System (EOS) planned for launch in the 1990s. The UARS combines a balanced program of experimental and theoretical investigations to perform diagnostic studies, qualitative model analysis, and quantitative measurements and comparative studies of the upper atmosphere. UARS provides theoretical and experimental investigations which pursue four specific research topics: atmospheric energy budget, chemistry, dynamics, and coupling processes. An international cadre of investigators was assembled by NASA to accomplish those scientific objectives. The observatory, its complement of ten state of the art instruments, and the ground system are nearing flight readiness. The timely UARS program will play a major role in providing data to understand the complex physical and chemical processes occurring in the upper atmosphere and answering many questions regarding the health of the ozone layer.

  14. The Science Manager's Guide to Case Studies

    SciTech Connect

    Branch, Kristi M.; Peffers, Melissa S.; Ruegg, Rosalie T.; Vallario, Robert W.

    2001-09-24

    This guide takes the science manager through the steps of planning, implementing, validating, communicating, and using case studies. It outlines the major methods of analysis, describing their relative merits and applicability while providing relevant examples and sources of additional information. Well-designed case studies can provide a combination of rich qualitative and quantitative information, offering valuable insights into the nature, outputs, and longer-term impacts of the research. An objective, systematic, and credible approach to the evaluation of U.S. Department of Energy Office of Science programs adds value to the research process and is the subject of this guide.

  15. [Familial hypobetalipoproteinemia. Familial study of 4 cases].

    PubMed

    Gay, G; Pessah, M; Bouma, M E; Roche, J F; Aymard, J P; Beucler, I; Aggerbeck, L P; Infante, R

    1990-01-01

    A familial study of four cases with hypobetalipoproteinemia is reported. Three members are heterozygous and one is homozygous. This congenital fat malabsorption in homozygous state is commonly associated with an absence of serum apoprotein B and LDL. Neuromuscular and ophthalmological signs are absent in this case. The major role of upper digestive endoscopy in the diagnostic procedure is emphasized. Histochemical and immunoenzymatic stains of enterocytes and intestinal organ culture show defective synthesis apo B in the homozygous patient. Studies of DNA polymorphism in the homozygous patient have shown that the apo B gene doesn't certain major insertions or deletions. These results are discussed. PMID:2096430

  16. Reference study to characterize plasma and magnetic properties of ultracool atmospheres

    NASA Astrophysics Data System (ADS)

    Rodríguez-Barrera, M. I.; Helling, Ch.; Stark, C. R.; Rice, A. M.

    2015-12-01

    Radio and X-ray emission from brown dwarfs (BDs) suggest that an ionized gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs (MD), BDs and giant gas planet to identify which ultracool objects are most susceptible to plasma and magnetic processes. Only thermal ionization is considered. We utilize the DRIFT-PHOENIX model grid where the local atmospheric structure is determined by the global parameters Teff, log (g) and [M/H]. Our results show that it is not unreasonable to expect Hα or radio emission to origin from BD atmospheres as in particular the rarefied upper parts of the atmospheres can be magnetically coupled despite having low degrees of thermal gas ionization. Such ultracool atmospheres could therefore drive auroral emission without the need for a companion's wind or an outgassing moon. The minimum threshold for the magnetic flux density required for electrons and ions to be magnetized is well above typical values of the global magnetic field of a BD and a giant gas planet. Na+, K+ and Ca+ are the dominating electron donors in low-density atmospheres (low log(g), solar metallicity) independent of Teff. Mg+ and Fe+ dominate the thermal ionization in the inner parts of MD atmospheres. Molecules remain unimportant for thermal ionization. Chemical processes (e.g. cloud formation) affecting the most abundant electron donors, Mg and Fe, will have a direct impact on the state of ionization in ultracool atmospheres.

  17. Global SF6 emission estimates inferred from atmospheric observations - a test case for Kyoto reporting

    NASA Astrophysics Data System (ADS)

    Levin, I.; Naegler, T.

    2009-04-01

    Sulphur hexafluoride (SF6) is one of the strongest greenhouse gases per molecule in the atmosphere. SF6 emissions are also one of the six greenhouse gases targeted for reduction under the Kyoto Protocol. Here we present a long-term data set of globally distributed high-precision atmospheric SF6 observations which show an increase in mixing ratios from near zero in the 1970s to a global mean value of 6.3 ppt by the end of 2007. Because of its long atmospheric lifetime of around 3000 years, the accumulation of SF6 in the atmosphere is a direct measure of its global emissions: Analysis of our long-term data records implies a decrease of global SF6 sources after 1995, most likely due to emission reductions in industrialised countries. However, after 1998 the global SF6 source increases again, which is probably due to enhanced emissions from transition economies such as in China and India. Moreover, observed north-south concentration differences in SF6 suggest that emissions calculated from statistical (bottom-up) information and reported by Annex II parties to the United Nations Framework Convention on Climate Change (UNFCCC) may be too low by up to 50%. This clearly shows the importance and need for atmospheric (top-down) validation of Kyoto reporting which is only feasible with a dense world-wide observational network for greenhouse and other trace gases. Other members of the Global SF6 Trends Team: R. Heinz (1), D. Osusko (1), E. Cuevas (2), A. Engel (3), J. Ilmberger (1), R.L. Langenfelds (4), B. Neininger (5), C.v. Rohden (1), L.P. Steele (4), A. Varlagin (6), R. Weller (7), D.E. Worthy (8), S.A. Zimov (9) (1) Institut für Umweltphysik, University of Heidelberg, 69120 Heidelberg, Germany, (2) Centro de Investigación Atmosférica de Izaña, Instituto Nacional de Meteorología (INM), 38071 Santa Cruz de Tenerife, Spain, (3) Institut für Atmosphäre und Umwelt, J.W. Goethe Universität Frankfurt, 60438 Frankfurt/Main, Germany, (4) Centre for Australian Weather and

  18. Spectroscopy in the study of planetary atmospheres - Abundances from the visible region

    NASA Technical Reports Server (NTRS)

    Lutz, B. L.

    1978-01-01

    Spectrophotometric studies of three molecular constituents - hydrogen, methane, and ammonia - identified in the visible region of the spectra of the outer planets are reviewed. The history of quadrupole line observations for hydrogen molecules and the significance of the HD molecule for the dipole spectrum are considered. Approaches to quantitative estimates of methane concentration in planetary atmospheres are explained, and the detection of ammonia in the atmospheres of Jupiter and Saturn is described.

  19. Climate and atmospheric modeling studies. Semiannual Progress Report, 1 Sep. 1991 - 31 Mar. 1992

    SciTech Connect

    Not Available

    1992-04-01

    The climate and atmosphere modeling research programs have concentrated on the development of appropriate atmospheric and upper ocean models, and preliminary applications of these models. Principal models are a one-dimensional radiative-convective model, a three-dimensional global model, and an upper ocean model. Principal applications were the study of the impact of CO2, aerosols, and the solar 'constant' on climate.

  20. Study of the high power laser-metal interactions in the gaseous atmospheres

    NASA Astrophysics Data System (ADS)

    Lugomer, Stjepan; Bitelli, G.; Stipancic, M.; Jovic, F.

    1994-08-01

    The tantalum and titanium plates were treated by pulsed, high power CO2 laser in the pressurized atmospheres of N2 and O2. Studies performed by the optical microscopy, microhardness measurements, and the auger electron spectroscopy revealed: (1) topographic modification of the surface caused by the temperature field; (2) metal hardening, caused by the laser shock; and (3) alloying/cladding, caused by the chemical reaction between the metal surface and the gaseous atmosphere.

  1. Study of the dynamics of meteoroids through the Earth's atmosphere and retrieval of meteorites

    NASA Astrophysics Data System (ADS)

    Guadalupe Cordero Tercero, Maria; Farah-Simon, Alejandro; Velázquez-Villegas, Fernando

    2016-07-01

    When a comet , asteroid or meteoroid impact with a planet several things can happen depending on the mass, velocity and composition of the impactor, if the planet or moon has an atmosphere or not, and the angle of impact. On bodies without an atmosphere like Mercury or the Moon, every object that strikes their surfaces produces impact craters with sizes ranging from centimeters to hundreds and even thousands of kilometers across. On bodies with an atmosphere, this encounter can produce impact craters, meteorites, meteors and fragmentation. Each and every one of these phenomena is interesting because they provide information about the surfaces and the geological evolution of solar system bodies. Meteors (shooting stars) are luminous wakes on the sky due to the interaction between the meteoroid and the Earth's atmosphere. A meteoroid is asteroidal or cometary material ranging in size from 2 mm to a few tens of meters. The smallest tend to evaporate at heights between 80 and 120 km. Objects of less than 2 mm are called micrometeorites. If the meteor brightness exceeds the brightness of Venus, the phenomenon is called a bolide or fireball. If a meteoroid, or a fragment of it, survives atmospheric ablation and it can be recovered on the ground, that piece is called a meteorite. Most meteoroids 2 meters long fragment suddenly into the atmosphere, it produces a shock wave that can affect humans and their environment like the Chelyabinsk event occurred on February 15, 2013 an two less energetic events in Mexico in 2010 and 2011. To understand the whole phenomenon, we proposed a video camera network for observing meteors. The objectives of this network are to: a) contribute to the study of the fragmentation of meteoroids in the Earth's atmosphere, b) determine values of important physical parameters; c ) study seismic waves produced by atmospheric shock waves, d) study the dynamics of meteoroids and f ) recover and study meteorites. During this meeting, the academic

  2. A study of global atmospheric budget and distribution of acetone using global atmospheric model STOCHEM-CRI

    NASA Astrophysics Data System (ADS)

    Khan, M. A. H.; Cooke, M. C.; Utembe, S. R.; Archibald, A. T.; Maxwell, P.; Morris, W. C.; Xiao, P.; Derwent, R. G.; Jenkin, M. E.; Percival, C. J.; Walsh, R. C.; Young, T. D. S.; Simmonds, P. G.; Nickless, G.; O'Doherty, S.; Shallcross, D. E.

    2015-07-01

    The impact of including a more detailed VOC oxidation scheme (CRI v2-R5) with a multi-generational approach for simulating tropospheric acetone is investigated using a 3-D global model, STOCHEM-CRI. The CRI v2-R5 mechanism contains photochemical production of acetone from monoterpenes which account for 64% (46.8 Tg/yr) of the global acetone sources in STOCHEM-CRI. Both photolysis and oxidation by OH in the troposphere contributes equally (42%, each) and dry deposition contributes 16% of the atmospheric sinks of acetone. The tropospheric life-time and the global burden of acetone are found to be 18 days and 3.5 Tg, respectively, these values being close to those reported in the study of Jacob et al. (2002). A dataset of aircraft campaign measurements are used to evaluate the inclusion of acetone formation from monoterpenes in the CRI v2-R5 mechanism used in STOCHEM-CRI. The overall comparison between measurements and models show that the parameterised approach in STOCHEM-NAM (no acetone formation from monoterpenes) underpredicts the mixing ratios of acetone in the atmosphere. However, using a detailed monoterpene oxidation mechanism forming acetone has brought the STOCHEM-CRI into closer agreement with measurements with an improvement in the vertical simulation of acetone. The annual mean surface distribution of acetone simulated by the STOCHEM-CRI shows a peak over forested regions where there are large biogenic emissions and high levels of photochemical activity. Year-long observations of acetone and methanol at the Mace Head research station in Ireland are compared with the simulated acetone and methanol produced by the STOCHEM-CRI and found to produce good overall agreement between model and measurements. The seasonal variation of model and measured acetone levels at Mace Head, California, New Hampshire and Minnesota show peaks in summer and dips in winter, suggesting that photochemical production may have the strongest effect on its seasonal trend.

  3. Case studies in organic contaminant hydrogeology

    NASA Astrophysics Data System (ADS)

    Baker, John A.

    1989-07-01

    The effective management of domestic solid waste and hazardous, toxic, and radioactive waste is a major problem in the area of environmental geology and water sciences over the world. This series of case studies of organic contaminants from both solid and hazardous waste disposal facilities provides examples of these problems. The facilities were investigated to determine risks and liabilities before acquisition, to determine the site hydrogeologic conditions for design of appropriate groundwater monitoring plans, and/or to determine the potential for groundwater contamination. The results of these studies and investigations by Waste Management Inc. (WMI) and its consultants have shown certain relationships in the distribution of organic pollutants to the different geologic and hydrogeologic charac teristics of each facility. In each of the case studies, all 129 priority pollutants were analyzed in private wells and/or monitoring wells at the request of regulatory agencies. The 31 volatile organic compounds (VOCs) of the priority pollutant list were the majority of the organic compounds detected and these data are evaluated in each case study. The case studies are on disposal facilities located in glacial tills, carbonaceous weathered clay soils, weathered shale, limestone bedrock, dolomite bedrock, and alluvial and sedimentary deposits. A brief discussion of groundwater quality impacts and remedial measures also is included.

  4. Atmospheric studies in complex terrain: a planning guide for future studies

    SciTech Connect

    Orgill, M.M.

    1981-02-01

    The objective of this study is to assist the US Department of Energy in Conducting its atmospheric studies in complex terrain (ASCOT0 by defining various complex terrain research systems and relating these options to specific landforms sites. This includes: (1) reviewing past meteorological and diffusion research on complex terrain; (2) relating specific terrain-induced airflow phenomena to specific landforms and time and space scales; (3) evaluating the technical difficulty of modeling and measuring terrain-induced airflow phenomena; and (4) avolving severdal research options and proposing candidate sites for continuing and expanding field and modeling work. To evolve research options using variable candidate sites, four areas were considered: site selection, terrain uniqueness and quantification, definition of research problems and research plans. 36 references, 111 figures, 20 tables.

  5. A numerical study of wind turbine wakes under various atmospheric stability conditions

    NASA Astrophysics Data System (ADS)

    Xie, Shengbai

    The goal of this research is to investigate the properties of wind turbine wakes and their interactions with the atmospheric boundary layer (ABL) via large-eddy simulations (LES) with special emphasis on the effects of atmospheric stability. The ABL is considered stable when the ground surface is cooler than the air, unstable when the opposite happens, and neutral when the temperature effect is negligible. In the literature, neutral conditions have been studied extensively, whereas the effects of stability have not. A new LES code, named Wind Turbine and Turbulence Simulator (WiTTS), was developed based on finite-difference (FD) schemes. First, the code's sensitivity to numerous aspects of the FD LES, such as the subgrid-scale (SGS) model, resolution, numerical treatment of the convective term, and filter types, was analyzed by simulating a neutral ABL. It was found that the Lagrangian-averaged scale-dependent (LASD) SGS model performs better than other scale-invariant Smagorinsky-type models. Second, the WiTTS was used to study the wakes from a miniature wind turbine inside a wind tunnel, following the setup of past experimental and numerical studies. It was found that those wakes are spatially anisotropic, with lateral growth faster than the vertical. Based on this, a new wake model is proposed and the Gaussian-type self-similarity is obtained for this simplified scenario. Third, to study a more realistic ABL, the stability conditions have been considered by the Boussinesq approximation and by varying thermal conditions on the ground surface, together with a constant Coriolis force. The LES results indicate that the properties of utility-scale wind turbine wakes are strongly correlated to the stability conditions. The wake recovery is enhanced by the increased turbulence due to buoyant convection in the unstable ABL, while in the stable ABL the spreading of the wake is significantly larger in the lateral direction than in the vertical direction. The stability

  6. Case study examples using self-assessment.

    PubMed

    Garstecki, D; Hutton, C L; Nerbonne, M A; Newman, C W; Smoski, W J

    1990-10-01

    The following case studies demonstrate the application of self-assessment techniques. The selection of procedures reported here is not meant to imply necessarily that these procedures are more or less effective or more widely used than other available self-assessment tests, but rather to illustrate the various purposes for which self-assessment tools may be employed. Case 1 illustrates the contribution of data obtained from the Hearing Performance Inventory (Giolas, Owens, Lamb, & Shubert, 1979) in the management and counseling of a severely hearing impaired adult. Case 2 involves the use of the Hearing Problem Inventory developed by Hutton in Atlanta (HPI-A, Hutton, 1987). Application of the Self-Assessment of Communication (SAC) and Significant Other Assessment of Communication (SOAC) (Schow and Nerbonne, 1982) is shown in Case 3, whereas Case 4 demonstrates the usefulness of the Hearing Handicap Inventory for the Elderly (HHIE, Ventry and Weinstein, 1982). Both the SAC/SOAC and HHIE batteries involve problem cases associated with hearing aid fitting and assessment of benefit. The final illustration (Case 5) is a report on the Children's Auditory Processing Performance Scale (CHAPPS), a new questionnaire developed by Smoski, Brunt, and Tannahill/ISHA (1987) for assessing parent's judgment of children's listening abilities (Appendix). The versatility of self-assessment applications across a broad assortment of impairment levels, age groups, and clinical settings is demonstrated in these cases. Hopefully the reader will see more clearly the application and value of these and other non-audiometric techniques and will be motivated to increase the use of self-assessment tools in the individual work setting. PMID:2269415

  7. A study of atmosphere-ionosphere-magnetosphere coupling

    NASA Technical Reports Server (NTRS)

    Raitt, W. J.; Paris, J. L.

    1982-01-01

    The properties of low energy plasma in the magnetosphere were predicted. The effects of wave particle interactions involving the concept of plasmons are studied, and quantum mechanical formulations are used for the processes occurring and bulk energization of the low energy plasma are investigated through the concept of the energy momentum tensor for the plasma and its electromagnetic environment.

  8. Case Studies of Altruistic Persons: AERA Roundtable.

    ERIC Educational Resources Information Center

    Stephens, William N.

    This document presents information from a body of research called Lives of Service, a collection of case studies of 32 altruistic adults. It begins with a review of the research on altruism, service orientation, giving, helpfulness, social responsibility, and voluntarism. Research on altruism in psychology and in other disciplines is included,…

  9. Lifelong Learning in SMEs: A Case Study.

    ERIC Educational Resources Information Center

    Holden, Rick; Smith, Vikki; Devins, Dave

    2002-01-01

    Learning centers using information-communications technologies were established in three British industrial estates. A case study of one organization shows the center contributed to lifelong learning and enhanced information technology training and employee confidence. Transfer of training and productivity improvements were not as clear. (Contains…

  10. An Effective School: A Case Study.

    ERIC Educational Resources Information Center

    Poindexter, Candace

    An elementary school principal's successful attempts to improve her inner-city school are described in this case study, which includes a diagram representing her formula for better education. The principal, a charismatic, elderly woman, takes an aggressive role in improving the school environment and student nutrition, encouraging and monitoring…

  11. Interdisciplinary Student Teams Projects: A Case Study

    ERIC Educational Resources Information Center

    Kruck, S. E.; Teer, Faye P.

    2009-01-01

    In today's organizations team work has become an integral part of the day-to-day routine. For this reason, University professors are including group projects in many courses. In such group assessments, we advocate the use of interdisciplinary teams, where possible. As a case study, we report an interdisciplinary group technical project with…

  12. A Case Study of Online Collaborative Learning

    ERIC Educational Resources Information Center

    Thompson, Ling; Ku, Heng-Yu

    2006-01-01

    This case study investigated 12 graduate students' online collaborative experiences and attitudes in an instructional design course. The instructor divided students into 4 groups based on their academic backgrounds. Content analysis of asynchronous group discussion board messages was used to measure degrees of collaboration of each group in terms…

  13. Firefighter Workplace Learning: An Exploratory Case Study

    ERIC Educational Resources Information Center

    Tracey, Edward A.

    2014-01-01

    Despite there being a significant amount of research investigating workplace learning, research exploring firefighter workplace learning is almost nonexistent. The purpose of this qualitative multi-case study was to explore how firefighters conceptualize, report, and practice workplace learning. The researcher also investigated how firefighters…

  14. Framing in the Field: A Case Study

    ERIC Educational Resources Information Center

    Benjamin, Diane

    2009-01-01

    Strategic Frame Analysis can inform the daily practice of policy advocates by bringing an evidence-based communications approach to their work. This case study of FrameWorks' decade-long association with the national Kids Count Network shares stories from advocates who are transforming their communications strategies, resulting in more effective…

  15. Grade One: Math Computation. Case Study #1

    ERIC Educational Resources Information Center

    Powell, Sarah R.; Seethaler, Pamela M.

    2007-01-01

    The purpose of this case study is to highlight the integral role that progress monitoring (PM) plays throughout any Response to Intervention (RTI) process. This example uses a three-level, responsiveness-to-intervention (RTI) method for identifying students with learning difficulties. Using a fictional first-grade classroom as the setting for…

  16. ESL and Digital Video Integration: Case Studies

    ERIC Educational Resources Information Center

    Li, J., Ed.; Gromik, N., Ed.; Edwards, N., Ed.

    2013-01-01

    It should come as no surprise that digital video technology is of particular interest to English language learners; students are drawn to its visual appeal and vibrant creative potential. The seven original case studies in this book demonstrate how video can be an effective and powerful tool to create fluid, fun, interactive, and collaborative…

  17. Experiencing Online Pedagogy: A Canadian Case Study

    ERIC Educational Resources Information Center

    Duncan, Heather E.; Barnett, John

    2010-01-01

    This case study explored the educational experiences of Canadian preservice teachers in a course designed to teach about online teaching. Students gained experience in course design and delivery, and safe and ethical behavior related to technology. Findings indicated that projects in which students actively applied their knowledge were more…

  18. Three Case Studies in Green Cleaning

    ERIC Educational Resources Information Center

    State Education Standard, 2012

    2012-01-01

    This article presents case studies from three districts implementing green cleaning. In 2008, Missouri passed legislation requiring state education officials to convene a committee of stakeholders with the purpose of developing green cleaning guidelines and specifications for schools. The guide, published by the Department of Elementary and…

  19. Value for Money Case Studies. Mendip Papers.

    ERIC Educational Resources Information Center

    Kedney, Bob, Ed.

    In response to a shift from the management of curriculum to the management of scarce resources to deliver a changing curriculum, this paper brings together three "value for money" case studies in college administration. The papers identify three levels of activity, ranging from the one-time opportunity for good housekeeping through tactical…

  20. Tachycardia During Resistance Exercise: A Case Study.

    ERIC Educational Resources Information Center

    Fry, Andrew C.; Parks, Michael J.

    2001-01-01

    This case study examined a weight-trained (WT) male who had an unusually high heart rate response to heavy resistance exercise and self-administered anabolic androgenic steroids as an ergogenic aid to training. The subject was compared to 18 other WT people. His tachycardia response occurred only in the presence of a pressure load and not with a…

  1. Physics Courses--Some Suggested Case Studies

    ERIC Educational Resources Information Center

    Swetman, T. P.

    1972-01-01

    To communicate the relevance and excitement of science activity to students, the use of more imaginative, and even openly speculative, case studies in physics courses is suggested. Some useful examples are Magnetic Monopoles, Constants, Black Holes, Antimatter, Zero Mass Particles, Tachyons, and the Bootstrap Hypothesis. (DF)

  2. Case Study of Home-School Visits

    ERIC Educational Resources Information Center

    Aguerrebere, Yolanda

    2009-01-01

    This case study evaluated one site of a California teacher home visit program. Home visits have been an important means of connecting families and schooling. In 1999, California inaugurated a statewide home visit program to promote effective partnership between home and school for low-achieving schools. At this site, families in 3 kindergarten…

  3. Learning To Teach Spanish: A Case Study.

    ERIC Educational Resources Information Center

    Velez-Rendon, Gloria

    This case study explores the student teaching experience of a Spanish language teacher candidate through her own eyes. It sheds light on how the participants' prior learning experience and beliefs inform her initial practice, how she develops her teaching skills, what contextual factors affect her learning-to-teach process, and the sources from…

  4. Performance Support Case Studies from IBM.

    ERIC Educational Resources Information Center

    Duke-Moran, Celia; Swope, Ginger; Morariu, Janis; deKam, Peter

    1999-01-01

    Presents two case studies that show how IBM addressed performance support solutions and electronic learning. The first developed a performance support and expert coaching solution; the second applied performance support to reducing implementation time and total cost of ownership of enterprise resource planning systems. (Author/LRW)

  5. WMOST v2 Case Study: Monponsett Ponds

    EPA Science Inventory

    This webinar presents an overview of the preliminary results of a case study application of EPA's Watershed Management Optimization Support Tool v2 (WMOST) for stakeholders in the Monponsett Ponds Watershed Workgroup. Monponsett Ponds is a large water system consisting of two ba...

  6. Semantically Redundant Language--A Case Study

    ERIC Educational Resources Information Center

    Rizza, Chris

    2009-01-01

    In this article, I discuss the concept of semantically redundant language through a case study of the Te Rauparaha Maori haka. I suggest that current linguistic theories cannot give a full account of ritualized speech events, of which the haka is an example, as these theories are based on a traditional dyadic model of interaction involving a…

  7. A Case Study in Learning to Unlearn

    ERIC Educational Resources Information Center

    Downes, Martin; Grummell, Bernie; Murphy, Conor; Ryan, Anne

    2015-01-01

    In this case study, Irish academics reflect on our involvement in a project--Transformative Engagement Network (TEN). This project aims to transform the nature of the engagement between the various stakeholders impacted by or concerned with climate change and to insert the voice and concerns of the most vulnerable food producers into climate…

  8. The Postmodern English Major: A Case Study.

    ERIC Educational Resources Information Center

    Schwartz, Lawrence

    2003-01-01

    Offers a case study in curriculum change that reveals a very different experience--one that demonstrates a discipline more alive than ever. Presents a story of how the lively canon debates prompted the English department at Montclair State University to restructure the English major. Finds that the culture wars, critical theory, poststructuralism,…

  9. LCA – Unique and Controversial Case Studies

    EPA Science Inventory

    This session will focus on case studies and applications that have a unique or controversial aspect. Some of the most recent topics that seem to have significant interest include: LCA-based product declarations, LCA-based standards, LCA-based labels, alternative energy, agricul...

  10. Case Study of Sabrina and Responses.

    ERIC Educational Resources Information Center

    Gourgey, Annette F.; Davis, Kevin; Lane, Linda; Smith, Lonna

    1997-01-01

    Presents a case study of an adult student preparing for her first year of college through a writing course and work in a writing workshop. Explains complicating circumstances in the student's life. Presents four professional responses commenting on the difficulties of the situation and possible solutions. (TB)

  11. Acquaintance Rape: A Case Study Approach.

    ERIC Educational Resources Information Center

    Marinelli, Rosalie D.

    1994-01-01

    Describes a case study approach to acquaintance rape used in a Personal Health and Lifestyles course at the University of Nevada in Reno that allows students to discuss the characters in a scenario, an instructional process seen as less threatening than describing personal experiences. (MDM)

  12. The Verbal Noncommunicator: A Case Study.

    ERIC Educational Resources Information Center

    Fujiki, Martin; Brinton, Bonnie

    1991-01-01

    This article presents a case study of a nine-year-old male with language impairment and specific pragmatic disabilities. His interactions with an adult, a language age-matched peer, and a chronological age-matched peer were observed and analyzed to determine conversational responsiveness and assertiveness. Findings support Fey's (1986) verbal…

  13. Aerospace Mechanisms and Tribology Technology: Case Studies

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter focuses attention on tribology technology practice related to vacuum tribology and space tribology. Two case studies describe aspects of real problems in sufficient detail for the engineer and the scientist to understand the tribological situations and the failures. The nature of the problems is analyzed and the range of potential solutions is evaluated. Courses of action are recommended.

  14. Climate wise case study compendium: Report 1

    SciTech Connect

    1997-02-01

    This case study compendium is one of several Climate Wise tools available to help interested companies identify cost-effective options. Climate Wise, a private-public partnership program, is a key Federal initiative to return greenhouse gas emissions to 1990 levels by 2000.

  15. Case Studies in Managing Psychological Depth.

    ERIC Educational Resources Information Center

    Ringer, Martin; Gillis, H. L.

    This paper outlines a model for assessing and managing psychological depth in outdoor and experiential group work, and presents two case studies of the complexity of such management in real life. The model contains eight levels of emotional risk and presents four criteria for assessing the level to which a particular event or discussion may lead…

  16. A Case Study in Acoustical Design.

    ERIC Educational Resources Information Center

    Ledford, Bruce R.; Brown, John A.

    1992-01-01

    Addresses concerns of both facilities planners and instructional designers in planning for the audio component of group presentations. Factors in the architectural design of enclosures for the reproduction of sound are described, including frequency, amplitude, and reverberation; and a case study for creating an acceptable enclosure is presented.…

  17. Library Virtual Tours: A Case Study

    ERIC Educational Resources Information Center

    Ashmore, Beth; Grogg, Jill E.

    2004-01-01

    Virtual tours delivered via the Web have become a common tool for both instruction and outreach. This article is a case study of the creation of a virtual tour for a university library and is intended to provide others interested in creating a virtual tour of their library the opportunity to learn from the mistakes and successes of fellow…

  18. Learning Machine Learning: A Case Study

    ERIC Educational Resources Information Center

    Lavesson, N.

    2010-01-01

    This correspondence reports on a case study conducted in the Master's-level Machine Learning (ML) course at Blekinge Institute of Technology, Sweden. The students participated in a self-assessment test and a diagnostic test of prerequisite subjects, and their results on these tests are correlated with their achievement of the course's learning…

  19. Case Studies: Windows onto Clinical Supervision.

    ERIC Educational Resources Information Center

    Nolan, Jim; And Others

    1993-01-01

    By examining the structures and activities common to six case studies of clinical teacher supervision, this article identifies five conditions that facilitate changes in teacher thinking and behavior: development of a supportive, collegial relationship; teacher control over supervision products; continuity over time; focused, descriptive records…

  20. Phonological Precedence in Dyslexia: A Case Study

    ERIC Educational Resources Information Center

    Schneider-Zioga, Patricia

    2012-01-01

    Developmental dyslexia is believed to involve a phonological deficit of which the exact properties have not been clearly established. This article presents the findings of a longitudinal case study that suggest that, at least for some people with dyslexia, the fundamental problem involves a disturbance of temporal-spatial ordering abilities. A…

  1. Acoustical case studies of three green buildings

    NASA Astrophysics Data System (ADS)

    Siebein, Gary; Lilkendey, Robert; Skorski, Stephen

    2005-04-01

    Case studies of 3 green buildings with LEED certifications that required extensive acoustical retrofit work to become satisfactory work environments for their intended user groups will be used to define areas where green building design concepts and acoustical design concepts require reconciliation. Case study 1 is an office and conference center for a city environmental education agency. Large open spaces intended to collect daylight through clerestory windows provided large, reverberant volumes with few acoustic finishes that rendered them unsuitable as open office space and a conference room/auditorium. Case Study 2 describes one of the first gold LEED buildings in the southeast whose primary design concepts were so narrowly focused on thermal and lighting issues that they often worked directly against basic acoustical requirements resulting in sound levels of NC 50-55 in classrooms and faculty offices, crosstalk between classrooms and poor room acoustics. Case study 3 is an environmental education and conference center with open public areas, very high ceilings, and all reflective surfaces made from wood and other environmentally friendly materials that result in excessive loudness when the building is used by the numbers of people which it was intended to serve.

  2. Physical Science Connected Classrooms: Case Studies

    ERIC Educational Resources Information Center

    Irving, Karen; Sanalan, Vehbi; Shirley, Melissa

    2009-01-01

    Case-study descriptions of secondary and middle school classrooms in diverse contexts provide examples of how teachers implement connected classroom technology to facilitate formative assessment in science instruction. Connected classroom technology refers to a networked system of handheld devices designed for classroom use. Teachers were…

  3. Simulations & Case Studies. [SITE 2002 Section].

    ERIC Educational Resources Information Center

    Seymour, Cathy R., Ed.

    This document contains the following papers on simulations and case studies from the SITE (Society for Information Technology & Teacher Education) 2002 conference: "3-D Virtual Classroom Technology" (Kimberly Arseneau Miller, Angela Glod); "Simulated Lesson Design Studios" (Willis Copeland); "Lights, Camera, Integration: Presentation Programs and…

  4. Delivering Online Examinations: A Case Study

    ERIC Educational Resources Information Center

    Howarth, Jason; Messing, John; Altas, Irfan

    2004-01-01

    This paper represents a brief case study of delivering online examinations to a worldwide audience. These examinations are delivered in partnership with a commercial online testing company as part of the Industry Master's degree at Charles Sturt University (CSU). The Industry Master's degree is an academic program for students currently employed…

  5. Comparative Environmental Threat Analysis: Three Case Studies.

    ERIC Educational Resources Information Center

    Latour, J. B.; Reiling, R.

    1994-01-01

    Reviews how carrying capacity for different environmental problems is operationalized. Discusses whether it is possible to compare threats, using the exceeding of carrying capacity as a yardstick. Points out problems in comparative threat analysis using three case studies: threats to European groundwater resources, threats to ecosystems in Europe,…

  6. New Case Studies of Citizen Action

    ERIC Educational Resources Information Center

    Tanner, Thomas

    1977-01-01

    Describes a six-unit case study curriculum package designed for secondary and college-level courses relating to environmental education. The units deal with nuclear power, stream channelization, a river dam project, overgrazing of public lands, agribusiness versus the family farm, and swamp preservation. (Author/DB)

  7. Sustainability in Housing: A Curriculum Case Study.

    ERIC Educational Resources Information Center

    Parrott, Kathleen; Emmel, Joann M.

    2001-01-01

    Explores the influence of environmental issues on the field of housing, from the perspective of sustainable housing. Presents a case study of the development of a college course to address these issues by integrating energy management, air quality, water quality, and waste management. (Author)

  8. Marietta Celebration of Unity Case Study.

    ERIC Educational Resources Information Center

    Philbin, Meg; Phillips, Rebecca

    This case study concerns the forming of a Marietta, Ohio unity committee, entitled Citizens for Social and Racial Justice, in response to the local Ku Klux Klan's (KKK) request for a parade permit in order to demonstrate against blacks in this city. Marietta, the county seat of Washington County, Ohio, has a population composed of both white and…

  9. CALIFORNIA PROJECT TALENT. IDENTIFICATION, CASE STUDY.

    ERIC Educational Resources Information Center

    RICE, JOSEPH P.; AND OTHERS

    THE USE OF CASE STUDIES CAN HELP THE TEACHER TO APPRECIATE INDIVIDUAL DIFFERENCES, TO CAPITALIZE ON INTERESTS AND ABILITIES, TO APPRECIATE AND UTILIZE EXCEPTIONAL SKILLS, AND TO SET UP APPROPRIATE DEVELOPMENTAL GOALS FOR INDIVIDUAL CHILDREN. AN OUTLINE FOR THE IDENTIFICATION PROCESS INCLUDES SCREENING (GROUP DEVICES), NOMINATION (STAFF MATCHES THE…

  10. It's Not Funny: A Case Study

    ERIC Educational Resources Information Center

    Méndez-Morse, Sylvia

    2015-01-01

    This case study may be used with personnel supervision, school law, and other school leadership courses. It describes the behavior and actions of one teacher toward another. Student discussions can focus on supervision, workplace mobbing, workplace bullying, as well as sexual harassment. Students should focus on a school leader's role in such…

  11. NACASETAC BAY: AN INTERACTIVE CASE STUDY

    EPA Science Inventory

    This interactive case study or "game" was created to provide a "hands on" experience in the application of a weight of evidence approach to sediment assessment. The game proceeds in two phases. In each phase the players work together as a group. A scenario is presented, and the g...

  12. A CASE STUDY OF ENVIRONMENTAL DATA MANAGEMENT

    EPA Science Inventory

    In order to support our ongoing research in watershed ecology and global climate change, we gather and analyze environmental data from several government agencies. This case study demonstrates a researcher’s approach to accessing, organizing, and using intersectoral data. T...

  13. Fraternization in Accounting Firms: A Case Study

    ERIC Educational Resources Information Center

    Heinze, Tim; Kizirian, Tim; Leese, Wallace

    2004-01-01

    This case study sheds light on how to avoid risks caused by manager-subordinate dating relationships (fraternization) such as employee misunderstandings, retaliation charges, favoritism complaints, wrongful termination lawsuits, and sexual harassment lawsuits, as well as associated ethical risks. Risk avoidance can be accomplished through a better…

  14. Teaching the Holocaust through Case Study

    ERIC Educational Resources Information Center

    Misco, Thomas

    2009-01-01

    This article responds to the curricular challenges teachers face with Holocaust education, including cursory treatments and a lack of focus on individual experiences. First, the author argues for a case-study approach to help students reengage concrete and complex features of the Holocaust as a point of departure for subsequent inquiry. In…

  15. The Campus Diversity Initiative: A Case Study

    ERIC Educational Resources Information Center

    Nayak, Sharada

    2005-01-01

    This Case Study presents the Campus Diversity Initiative (CDI), a three-phase project lead by the Educational Resources Project Centre Trust, in New Delhi, India. In a historic and cultural context different from that of India, the American Diversity Initiative was launched by the Ford Foundation in 1990 and addressed their diversity issues by…

  16. Interactive Videodisc Case Studies for Medical Education

    PubMed Central

    Harless, William G.; Zier, Marcia A.; Duncan, Robert C.

    1986-01-01

    The TIME Project of the Lister Hill National Center for Biomedical Communications is using interactive videodisc, microprocessor and voice recognition technology to create patient simulations for use in the training of medical students. These interactive case studies embody dramatic, lifelike portrayals of the social and medical conditions of a patient and allow uncued, verbal intervention by the student for independent clinical decisions.

  17. School University Collaboration: A Case Study.

    ERIC Educational Resources Information Center

    Hutchison, Robert; And Others

    A case study of school-university collaboration between Starkville School District (Mississippi) and Mississippi State University (MSU) explored the process of collaboration and the ingredients for successful implementation. MSU offered grant opportunities for university faculty to work with local school district personnel. Starkville School…

  18. The Induction of Marketing Teachers: Case Studies.

    ERIC Educational Resources Information Center

    Heath-Camp, Betty; And Others

    As part of a larger, 5-year national project, case study analyses were conducted of the induction experiences of two beginning teachers of marketing education. One teacher (Mary) entered the profession through a traditional teacher education program in marketing education. The other (Jake) obtained certification based on extensive experience in…

  19. Aerospace Mechanisms and Tribology Technology: Case Study

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.

    1999-01-01

    This paper focuses attention on tribology technology practice related to vacuum tribology. A case study describes an aspect of a real problem in sufficient detail for the engineer and scientist to understand the tribological situation and the failure. The nature of the problem is analyzed and the tribological properties are examined.

  20. Evaluating Innovation: The Case Study Approach.

    ERIC Educational Resources Information Center

    Saez, Maria Jose; Carretero, Antonia J.

    1998-01-01

    Characterized the methodology of case studies, using examples from science education, with regard to their potential for the analysis of innovation and formulation of emerging trends. The theoretical and empirical support of evaluation will generate a call for negotiation as the formula that regulates the assessment of a program's efficiency and…

  1. Pilot study of ultra-high energy Cosmic rays through their Space - Atmospheric interactions - COSAT

    NASA Astrophysics Data System (ADS)

    Gina Isar, Paula; Nicolae, Doina

    2015-03-01

    One hundred years after the discovery of cosmic rays, the study of charged ultra-high energy cosmic rays remains a vital activity in fundamental physics. While primary cosmic rays could not be measured directly until it was possible to get the detectors high in the atmosphere using balloons or spacecraft, nowadays very energetic cosmic rays are detected indirectly by ground-based experiments measuring their Extensive Air Showers (EAS) induced Cherenkov and fluorescent light, or radio waves. Moreover, all cosmic ray measurements (performed either from space or ground) rely on accurate understandings of atmospheric phenomena. The concept of the COSAT project is the inter-link between Astroparticle Physics, Remote Sensing and Atmospheric Environment, willing to investigate the energetic cosmic rays physical processes using the atmosphere as a detector in order to identify potential scientific niches in the field of space sciences. A short introduction on the current status and perspectives of the national partnership COSAT project will be given.

  2. High-Speed Research: 1994 Sonic Boom Workshop: Atmospheric Propagation and Acceptability Studies

    NASA Technical Reports Server (NTRS)

    Mccurdy, David A. (Editor)

    1994-01-01

    The workshop proceedings include papers on atmospheric propagation and acceptability studies. Papers discussing atmospheric effects on the sonic boom waveform addressed several issues. It has long been assumed that the effects of molecular relaxation are adequately accounted for by assuming that a steady state balance between absorption and nonlinear wave steepening exists. It was shown that the unsteadiness induced by the nonuniform atmosphere precludes attaining this steady state. Further, it was shown that the random atmosphere acts as a filter, effectively filtering out high frequency components of the distorted waveform. Several different propagation models were compared, and an analysis of the sonic boom at the edge of the primary carpet established that the levels there are bounded. Finally, a discussion of the levels of the sonic boom below the sea surface was presented.

  3. Study on the characteristics of different infrared transmission in atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Wang, Zhe; Wang, Jing-yuan; Xu, Zhi-yong; Chang, Shuai; Zhao, Ji-yong; Chen, Yi-wang; Wang, Rong; Wei, Yi-mei

    2015-10-01

    It is known theoretically that the long wavelength infrared has better performance when transmitting in atmospheric turbulence. In order to evaluate the influence of the atmospheric turbulence quantificationally, the characteristics of different infrareds transmission in atmospheric turbulence are simulated and studied. A series of time relevant phase screens of atmospheric turbulence are simulated based on Fourier transform method proposed by McGlamery. Wind speed and direction are introduced in the meantime. Wavefront distortion, image spot dancing and spreading, receive loss of different wavelengths (0.85μm, 3.6μm, 10.6μm) are simulated respectively and compared to each other. The results show that the performances of long wavelength infrared (10.6μm) are the best, mid wavelength infrared (3.6μm) takes the second place and short wavelength infrared (0.85μm) is the worst.

  4. Study of new systems concepts for a Titan atmospheric probe

    NASA Technical Reports Server (NTRS)

    Bernard, Doug; Citron, Todd; Drean, Robert; Lewis, Scott; Lo, Martin; Mccarthy, John; Soderblom, Robert; Steffy, Dave; Vargas, Tina; Wolff, Marty

    1986-01-01

    Results of a systems concepts study for a Titan Probe were examined. The key tradeoffs performed are described in detail. Mass breakdown of each Probe subsystem or major element were given. The mission analysis performed to determine compliance with the high altitude sampling and descent time requirements are described. The baseline Descent Module design was derived. The element of the Probe System left on the Carrier after separation were described.

  5. Design and implementation of flexible laboratory system for beam propagation study through weak atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Rickenstorff, Carolina; Rodrigo, Jóse A.; Alieva, Tatiana

    2016-04-01

    Different applications such as astronomy, remote optical sensing and free space optical communications, among others, require both numerical and laboratory experimental simulations of beam propagation through turbulent atmosphere prior to an outdoor test. While rotating phase plates or hot chambers can be applied to such studies, they do not allow changing the atmospheric conditions and the propagation distance in situ. In contrast, the spatial light modulators (SLMs) are a flexible alternative for experimental turbulence simulation. In this work we consider an experimental setup comprising two SLMs for studying laser beam propagation in weak atmospheric turbulence. The changes of atmospheric conditions and propagation distances are properly achieved by the adjustment of the phase screens and the focal distances of digital lenses implemented in both SLMs. The proposed system can be completely automatized and all its elements are in fixed positions avoiding mechanical misalignment. Its design, propagation distance and atmospheric condition adjustment are provided. The setup performance is verified by numerical simulation of Gaussian beam propagation in the weak turbulence regime. The obtained parameters: scintillation index, beam wander and spreading are compared to their theoretical counterparts for different propagation distances and atmospheric conditions.

  6. Experimental Study of the EM Transmission Properties of the Marine Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Hristov, T.; Friehe, C.; Anderson, K.

    2003-04-01

    The propagation of electro-magnetic signals over the ocean is primarily affected by atmospheric refraction and scattering from the rough ocean surface. Wave-guides (also known as refractive ducts) occurring in the first tens of meters above the sea surface have been modeled extensively, as they influence communications. However, discrepancies between models and measurements have been detected. Here we study experimentally the structure of the atmospheric refractive index and the ocean surface statistics, pertinent to EM signals scattering. The structure and the dynamics the marine atmospheric boundary layer is profoundly affected by the ocean surface waves, which deform the mean wind flow streamlines. In the presence of gradients of the atmospheric humidity and temperature, the deformation of the streamlines displaces the sheared profiles of these quantities and leads to wave-induced fluctuations of the atmospheric refractive index. As a result, radio and optical signals propagating over the ocean encounter a semi-periodic refractive structure, which along with the turbulence can degrade signal's energy. The wave-induced fluctuations of the refractive index are unique to the oceanic environment. Their structure function does not follow the power 2/3 scaling law, valid for turbulent fluctuations, and thus their influence should be studied separately. We analyze data of atmospheric turbulence, humidity, temperature, and sea surface temperature and waves from the Rough Evaporation Duct experiment, conducted in part from the instrument platform FLIP in the open ocean North of Oahu, Hawaii.

  7. Studies of atmospheric refraction effects on laser data

    NASA Technical Reports Server (NTRS)

    Dunn, P. J.; Pearce, W. A.; Johnson, T. S.

    1982-01-01

    The refraction effect from three perspectives was considered. An analysis of the axioms on which the accepted correction algorithms were based was the first priority. The integrity of the meteorological measurements on which the correction model is based was also considered and a large quantity of laser observations was processed in an effort to detect any serious anomalies in them. The effect of refraction errors on geodetic parameters estimated from laser data using the most recent analysis procedures was the focus of the third element of study. The results concentrate on refraction errors which were found to be critical in the eventual use of the data for measurements of crustal dynamics.

  8. Studies of atmospheric refraction effects on laser data

    NASA Astrophysics Data System (ADS)

    Dunn, P. J.; Pearce, W. A.; Johnson, T. S.

    1982-06-01

    The refraction effect from three perspectives was considered. An analysis of the axioms on which the accepted correction algorithms were based was the first priority. The integrity of the meteorological measurements on which the correction model is based was also considered and a large quantity of laser observations was processed in an effort to detect any serious anomalies in them. The effect of refraction errors on geodetic parameters estimated from laser data using the most recent analysis procedures was the focus of the third element of study. The results concentrate on refraction errors which were found to be critical in the eventual use of the data for measurements of crustal dynamics.

  9. Empathy Development Through Case Study and Simulation.

    PubMed

    Mennenga, Heidi A; Bassett, Susan; Pasquariello, Libby

    2016-01-01

    Because empathy is integral to the nurse-patient relationship, nurse educators are challenged to explore teaching strategies that may aid in the development of empathy among students. The purpose of this study was to determine whether consistent exposure to a single patient through case study and simulation had an impact on empathy levels in senior-level baccalaureate nursing students. Results provide interesting conclusions for faculty members and offer a basis for ongoing discussion. PMID:26448156

  10. Thermochromatography study of volatile tellurium species in various gas atmospheres

    NASA Astrophysics Data System (ADS)

    Maugeri, Emilio Andrea; Neuhausen, Jörg; Eichler, Robert; Piguet, David; Schumann, Dorothea

    2014-09-01

    The adsorption interaction of tellurium species with fused silica was studied by thermochromatography. Trace amounts of tellurium were obtained by irradiating elemental tin with α-particles. Different tellurium species were obtained using carrier gases with varied redox potential. Adsorption enthalpies of the obtained species were calculated allowing for the identification of some species. Elemental tellurium or SnTe was deposited in thermochromatography experiments when using both dried and deoxygenated He and H2 as carrier gases. Tellurium dioxide was deposited in thermochromatography experiments when using dry oxygen as carrier gas. Tellurium dioxide was found to be significantly less volatile compared to elemental Te or SnTe. The deposition of a species with still lower volatility occurring under less oxidizing conditions was tentatively assigned to tellurium monoxide, TeO. Species more volatile than elemental tellurium or SnTe, most likely Te-hydroxides, were detected in experiments using moist H2 as carrier gas. In moist oxidizing gas, species more volatile than TeO2 were found, most likely Te-oxyhydroxides. The obtained results provide valuable input to design experiments for studying the volatility of tellurium's heavier homologue polonium and its compounds, which represent one of the major radiological concerns for the use of lead-bismuth-eutectic as coolant and target material for innovative accelerator-driven systems or spallation sources.

  11. Coupling atmospheric, hydrological and hydraulic models to develop a catalogue of worst-case scenarios for extreme flooding in Switzerland

    NASA Astrophysics Data System (ADS)

    José Gómez-Navarro, Juan; Felder, Guido; Raible, Christoph C.; Martius, Olivia; Rössler, Ole

    2015-04-01

    Extreme flooding are a natural threat that leads to great economical cost, especially in densely populated areas such as Switzerland. However, the study of such extremes is difficult due to the fact they are, by definition, very rare, whereas the instrumental period is relatively short. This hampers the study of events with large return periods, which are precisely those more relevant from the impact point of view. Thus, new methodologies have to be developed that provide a deeper understanding of such disastrous situations and their driving mechanisms. This study employs a chain of models that allow the study of the frequency and severity of such situations and to analyse their driving physical mechanisms. First, a long climate simulation (a control simulation spanning more than 500 years) with the comprehensive Global Circulation Model (GCM) CESM1 is used as test-bed for producing a dataset of several centuries of physically consistent climate. This data is then used to filter out a number of case studies corresponding to extreme situations, which are selected as candidates for further analysis. However, although the physical consistency of this simulation ensures that the synoptic circulation leading to the selected events is plausible, the global model employs a coarse spatial resolution (1 degree) that precludes the accurate simulation of the precipitation in areas of complex topography such as Switzerland. Hence, once the dates of the candidate cases are selected within the GCM run, this dataset is downscaled with the Regional Climate Model (RCM) WRF. The RCM implements a spatial resolution of 2 km over the entire alpine area, which allows it to reproduce more accurately the precipitation induced by interactions between the large-scale forcing and the orography. The results show that WRF is able to improve the simulation of precipitation compared to the GCM alone. Although the large-scale flow and the location of the precipitation maxima is very similar in

  12. Seismic damage to pipeline; Case study

    SciTech Connect

    O'Rourke, M.J.; Ayala, G. . Dept. of Civil Engineering)

    1990-03-01

    A case study of damage to a welded steel pipeline in Mexico City, caused by the 1985 Michoacan earthquake, is presented. Seismic damage to pipelines in past earthquakes is briefly reviewed. The damage has typically been due to seismic wave propagation or permanent ground deformations, such as faulting, landslides, or lateral spreads. Physical characteristics of the case study pipeline, pertinent soil conditions, recorded ground motion, and observed seismic damage in Mexico City are then presented. The recorded ground motion in the lake zone of Mexico City suggests a significant contribution from Rayleigh waves. A previously developed analysis procedure is used to estimate stress induced by seismic wave propagation in the case study pipeline. The pipeline stress is a function of the amplitude and wavelength of the ground strain, maximum friction forces at the soil-pipe interface, and the stress-strain characteristics of the pipeline material. It is shown that the estimated stress is only slightly less than the local compressional buckling stress for the case history pipeline.

  13. Assessment of Polarization Effect on Efficiency of Levenberg-Marquardt Algorithm in Case of Thin Atmosphere Over Black Surface

    NASA Technical Reports Server (NTRS)

    Korkin, S.; Lyapustin, A.

    2012-01-01

    The Levenberg-Marquardt algorithm [1, 2] provides a numerical iterative solution to the problem of minimization of a function over a space of its parameters. In our work, the Levenberg-Marquardt algorithm retrieves optical parameters of a thin (single scattering) plane parallel atmosphere irradiated by collimated infinitely wide monochromatic beam of light. Black ground surface is assumed. Computational accuracy, sensitivity to the initial guess and the presence of noise in the signal, and other properties of the algorithm are investigated in scalar (using intensity only) and vector (including polarization) modes. We consider an atmosphere that contains a mixture of coarse and fine fractions. Following [3], the fractions are simulated using Henyey-Greenstein model. Though not realistic, this assumption is very convenient for tests [4, p.354]. In our case it yields analytical evaluation of Jacobian matrix. Assuming the MISR geometry of observation [5] as an example, the average scattering cosines and the ratio of coarse and fine fractions, the atmosphere optical depth, and the single scattering albedo, are the five parameters to be determined numerically. In our implementation of the algorithm, the system of five linear equations is solved using the fast Cramer s rule [6]. A simple subroutine developed by the authors, makes the algorithm independent from external libraries. All Fortran 90/95 codes discussed in the presentation will be available immediately after the meeting from sergey.v.korkin@nasa.gov by request.

  14. Earth atmospheric entry studies for manned Mars missions

    NASA Technical Reports Server (NTRS)

    Tauber, M. E.; Palmer, G. E.; Yang, Lily

    1990-01-01

    Decelerations, heating rates, and total heat loads encountered when returning from Mars to earth at entry speeds of 12 km/sec to 16 km/sec are studied. For entry at 14 km/sec, it is found that a lift/drag ratio (L/D) of 0.5 is required to provide a guidance corridor margin near 1 deg for the specified deceleration limit of 5 g. For a blunted, raked cone with an L/D = 0.5, the peak heating rate near the aft end of the forebody varies from 0.14 to 0.23 kW/sq cm for laminar flow. If ablation triggers boundary layer transition, the peak heating can rise to 0.5 or up to 0.72 kW/sq cm. All heating rates are sufficiently high to make ablative heat shields necessary.

  15. A Study of Airline Passenger Susceptibility to Atmospheric Turbulence Hazard

    NASA Technical Reports Server (NTRS)

    Stewart, Eric C.

    2000-01-01

    A simple, generic, simulation math model of a commercial airliner has been developed to study the susceptibility of unrestrained passengers to large, discrete gust encounters. The math model simulates the longitudinal motion to vertical gusts and includes (1) motion of an unrestrained passenger in the rear cabin, (2) fuselage flexibility, (3) the lag in the downwash from the wing to the tail, and (4) unsteady lift effects. Airplane and passenger response contours are calculated for a matrix of gust amplitudes and gust lengths of a simulated mountain rotor. A comparison of the model-predicted responses to data from three accidents indicates that the accelerations in actual accidents are sometimes much larger than the simulated gust encounters.

  16. The atmospheric inventory of Xenon and noble cases in shales The plastic bag experiment

    NASA Technical Reports Server (NTRS)

    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.

  17. Preentry communications study. Outer planets atmospheric entry probe

    NASA Technical Reports Server (NTRS)

    Hinrichs, C. A.

    1976-01-01

    A pre-entry communications study is presented for a relay link between a Jupiter entry probe and a spacecraft in hyperbolic orbit. Two generic communications links of interest are described: a pre-entry link to a spun spacecraft antenna, and a pre-entry link to a despun spacecraft antenna. The propagation environment of Jupiter is defined. Although this is one of the least well known features of Jupiter, enough information exists to reasonably establish bounds on the performance of a communications link. Within these bounds, optimal carrier frequencies are defined. The next step is to identify optimal relative geometries between the probe and the spacecraft. Optimal trajectories are established for both spun and despun spacecraft antennas. Given the optimal carrier frequencies, and the optimal trajectories, the data carrying capacities of the pre-entry links are defined. The impact of incorporating pre-entry communications into a basic post entry probe is then assessed. This assessment covers the disciplines of thermal control, power source, mass properties and design layout. A conceptual design is developed of an electronically despun antenna for use on a Pioneer class of spacecraft.

  18. A general circulation model study of atmospheric carbon monoxide

    NASA Technical Reports Server (NTRS)

    Pinto, J. P.; Rind, D.; Russell, G. L.; Lerner, J. A.; Hansen, J. E.; Yung, Y. L.; Hameed, S.

    1983-01-01

    The carbon monoxide cycle is studied by incorporating the known and hypothetical sources and sinks in a tracer model that uses the winds generated by a general circulation model. Photochemical production and loss terms, which depend on OH radical concentrations, are calculated in an interactive fashion. The computed global distribution and seasonal variations of CO are compared with observations to obtain constraints on the distribution and magnitude of the sources and sinks of CO, and on the tropospheric abundance of OH. The simplest model that accounts for available observations requires a low latitude plant source of about 1.3 x 10 to the 15th g/yr, in addition to sources from incomplete combustion of fossil fuels and oxidation of methane. The globally averaged OH concentration calculated in the model is 750,000/cu cm. Models that calculate globally averaged OH concentrations much lower than this nominal value are not consistent with the observed variability of CO. Such models are also inconsistent with measurements of CO isotopic abundances, which imply the existence of plant sources.

  19. Study on enhanced atmospheric dispersion of 41Ar at the Trombay site.

    PubMed

    Chatterjee, M K; Divkar, J K; Patil, S S; Singh, Rajvir; Pradeepkumar, K S; Sharma, D N

    2013-08-01

    An extensive study has been carried out within the site of Bhabha Atomic Research Centre, Trombay, for examining the atmospheric dispersion of (41)Ar released from research reactors. The release rate, release height, meteorological parameters and geographical information were used to establish correlation between theoretical estimation using Gaussian plume dispersion model (GPDM) and dose/dose rate data obtained from Gammatracers (GTs). Ten monitoring locations were selected in five sectors and at different downwind distances from the release point. Analysis of dose rate data shows that the maximum dose rate (7.19 μSv h(-1)) and the total annual dose (1051 μSv) were observed at a downwind distance of 0.36 km. Average dose rates of all monitoring locations were varying from 0.03±0.02 to 0.12±0.07 μSv h(-1). The average dose rate increases at the monitoring locations placed at N to NE sectors during monsoon, and for monitoring locations placed at SW and SSE sectors during winter. The maximum dose rates, monthly and annual doses recorded by GT, have been compared with predicted values. Most of the locations show statistically significant coherence in the case of monthly dose. PMID:23413091

  20. Generating grounded theory: two case studies.

    PubMed

    Mullen, P D

    1985-01-01

    An inductive research method known as grounded theory is described as a means of building conceptual bridges between real-life situations and formal theory. The procedures are detailed and illustrated via two case studies. The first is a study of the social-psychological problem of cutting losses among heart patients through three stages of recovery. The process of extending the theory generated with the heart patients to other invisible physical impairments and across both visible and invisible chronic conditions is outlined. The second case study offers an example of a structurally-oriented theory, developed from participant observations of the processes of managing patients, staff, and neighbors for an "antipsychiatric" treatment facility for juvenile schizophrenics. PMID:20841268