WorldWideScience

Sample records for atmospheric radiation measurement

  1. Atmospheric Radiation Measurement Program plan

    International Nuclear Information System (INIS)

    In order to understand energy's role in anthropogenic global climate change, significant reliance is being placed on General Circulation Models (GCMs). A major goal is to foster the development of GCMs capable of predicting the timing and magnitude of greenhouse gas-induced global warming and the regional effects of such warming. The Atmospheric Radiation Measurement (ARM) Program will contribute to the Department of Energy goal by improving the treatment of cloud radiative forcing and feedbacks in GCMs. Two issues will be addressed: the radiation budget and its spectral dependence and the radiative and other properties of clouds. The experimental objective of the ARM Program is to characterize empirically the radiative processes in the Earth's atmosphere with improved resolution and accuracy. A key to this characterization is the effective treatment of cloud formation and cloud properties in GCMs. Through this characterization of radiative properties, it will be possible to understand both the forcing and feedback effects. 19 refs., 4 figs., 2 tabs

  2. Atmospheric Radiation Measurement Program Plan

    International Nuclear Information System (INIS)

    In order to understand energy's role in anthropogenic global climate change, significant reliance is being placed on General Circulation Models (GCMs). A major goal of the Department is to foster the development of GCMs capable of predicting the timing and magnitude of greenhouse gas-induced global warming and the regional effects of such warming. DOE research has revealed that cloud radiative feedback is the single most important effect determining the magnitude of possible climate responses to human activity. However, cloud radiative forcing and feedbacks are not understood at the levels needed for reliable climate prediction. The Atmospheric Radiation Measurement (ARM) Program will contribute to the DOE goal by improving the treatment of cloud radiative forcing and feedbacks in GCMs. Two issues will be addressed: the radiation budget and its spectral dependence and the radiative and other properties of clouds. Understanding cloud properties and how to predict them is critical because cloud properties may very well change as climate changes. The experimental objective of the ARM Program is to characterize empirically the radiative processes in the Earth's atmosphere with improved resolution and accuracy. A key to this characterization is the effective treatment of cloud formation and cloud properties in GCMs. Through this characterization of radiative properties, it will be possible to understand both the forcing and feedback effects. GCM modelers will then be able to better identify the best approaches to improved parameterizations of radiative transfer effects. This is expected to greatly improve the accuracy of long-term, GCM predictions and the efficacy of those predictions at the important regional scale, as the research community and DOE attempt to understand the effects of greenhouse gas emissions on the Earth's climate. 153 refs., 24 figs., 6 tabs

  3. Satellite data sets for the atmospheric radiation measurement (ARM) program

    Energy Technology Data Exchange (ETDEWEB)

    Shi, L.; Bernstein, R.L. [SeaSpace Corp., San Diego, CA (United States)

    1996-04-01

    This abstract describes the type of data obtained from satellite measurements in the Atmospheric Radiation Measurement (ARM) program. The data sets have been widely used by the ARM team to derive cloud-top altitude, cloud cover, snow and ice cover, surface temperature, water vapor, and wind, vertical profiles of temperature, and continuoous observations of weather needed to track and predict severe weather.

  4. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    LR Roeder

    2008-12-01

    The Importance of Clouds and Radiation for Climate Change: The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols, can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To reduce these scientific uncertainties, the ARM Program uses a unique twopronged approach: • The ARM Climate Research Facility, a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes; and • The ARM Science Program, focused on the analysis of ACRF and other data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report provides an overview of each of these components and a sample of achievements for each in fiscal year (FY) 2008.

  5. Atmospheric radiation measurement program facilities newsletter, June 2002.; TOPICAL

    International Nuclear Information System (INIS)

    ARM Intensive Operational Period Scheduled to Validate New NASA Satellite-Beginning in July, all three ARM sites (Southern Great Plains[SGP], North Slope of Alaska, and Tropical Western Pacific; Figure 1) will participate in the AIRS Validation IOP. This three-month intensive operational period (IOP) will validate data collected by the satellite-based Atmospheric Infrared Sounder (AIRS) recently launched into space. On May 4, the National Aeronautics and Space Administration (NASA) launched Aqua, the second spacecraft in the Earth Observing System (EOS) series. The EOS satellites monitor Earth systems including land surfaces, oceans, the atmosphere, and ice cover. The first EOS satellite, named Terra, was launched in December 1999. The second EOS satellite is named Aqua because its primary focus is understanding Earth's water cycle through observation of atmospheric moisture, clouds, temperature, ocean surface, precipitation, and soil moisture. One of the instruments aboard Aqua is the AIRS, built by the Jet Propulsion Laboratory, a NASA agency. The AIRS Validation IOP complements the ARM mission to improve understanding of the interactions of clouds and atmospheric moisture with solar radiation and their influence on weather and climate. In support of satellite validation IOP, ARM will launch dedicated radiosondes at all three ARM sites while the Aqua satellite with the AIRS instrument is orbiting overhead. These radiosonde launches will occur 45 minutes and 5 minutes before selected satellite overpasses. In addition, visiting scientists from the Jet Propulsion Laboratory will launch special radiosondes to measure ozone and humidity over the SGP site. All launches will generate ground-truth data to validate satellite data collected simultaneously. Data gathered daily by ARM meteorological and solar radiation instruments will complete the validation data sets. Data from Aqua-based instruments, including AIRS, will aid in weather forecasting, climate modeling, and

  6. Science Plan for the Atmospheric Radiation Measurement Program (ARM)

    International Nuclear Information System (INIS)

    The purpose of this Atmospheric Radiation Measurement (ARM) Science Plan is to articulate the scientific issues driving the ARM Program, and to relate them to DOE's programmatic objectives for ARM, based on the experience and scientific progress gained over the past five years. ARM programmatic objectives are to: (1) Relate observed radiative fluxes and radiances in the atmosphere, spectrally resolved and as a function of position and time, to the temperature and composition of the atmosphere, specifically including water vapor and clouds, and to surface properties, and sample sufficient variety of situations so as to span a wide range of climatologically relevant possibilities; (2) develop and test parameterizations that can be used to accurately predict the radiative properties and to model the radiative interactions involving water vapor and clouds within the atmosphere, with the objective of incorporating these parameterizations into general circulation models. The primary observational methods remote sending and other observations at the surface, particularly remote sensing of clouds, water vapor and aerosols

  7. Measurement of microwave radiation from electron beam in the atmosphere

    Science.gov (United States)

    Ohta, I. S.; Akimune, H.; Fukushima, M.; Ikeda, D.; Inome, Y.; Matthews, J. N.; Ogio, S.; Sagawa, H.; Sako, T.; Shibata, T.; Yamamoto, T.

    2016-02-01

    We report the use of an electron light source (ELS) located at the Telescope Array Observatory in Utah, USA, to measure the isotropic microwave radiation from air showers. To simulate extensive air showers, the ELS emits an electron beam into the atmosphere and a parabola antenna system for the satellite communication is used to measure the microwave radiation from the electron beam. Based on this measurement, an upper limit on the intensity of a 12.5 GHz microwave radiation at 0.5 m from a 1018 eV air shower was estimated to be 3.96×10-16 W m-2 Hz-1 with a 95% confidence level.

  8. Atmospheric thermal radiation from historical measurements to investigations of the Earth's greenhouse effect

    OpenAIRE

    Rolf Philipona

    2013-01-01

    Here, we recall first quantitative measurements of terrestrial and atmospheric thermal infrared radiation that were made about hundred years ago, and relate them to present day radiation budget measurements and greenhouse effect investigations through the atmosphere. At the beginning of the 20th century measurements of the effective terrestrial radiation and the counter-radiation of the atmosphere were of great interest primarily to prove theoretical aspects of the Earth radiation balance...

  9. Atmospheric radiation measurement program facilities newsletter, September 2001.; TOPICAL

    International Nuclear Information System (INIS)

    Our Changing Climate-Is our climate really changing? How do we measure climate change? How can we predict what Earth's climate will be like for generations to come? One focus of the Atmospheric Radiation Measurement (ARM) Program is to improve scientific climate models enough to achieve reliable regional prediction of future climate. According to the Environmental Protection Agency (EPA), the global mean surface temperature has increased by 0.5-1.0 F since the late 19th century. The 20th century's 10 warmest years all occurred in the last 15 years of the century, with 1998 being the warmest year of record. The global mean surface temperature is measured by a network of temperature-sensing instruments distributed around the world, including ships, ocean buoys, and weather stations on land. The data from this network are retrieved and analyzed by various organizations, including the National Aeronautics and Space Administration, the National Oceanic and Atmospheric Administration, and the World Meteorological Organization. Worldwide temperature records date back to 1860. To reconstruct Earth's temperature history before 1860, scientists use limited temperature records, along with proxy indicators such as tree rings, pollen records, and analysis of air frozen in ancient ice. The solar energy received from the sun drives Earth's weather and climate. Some of this energy is reflected and filtered by the atmosphere, but most is absorbed by Earth's surface. The absorbed solar radiation warms the surface and is re-radiated as heat energy into the atmosphere. Some atmospheric gases, called greenhouse gases, trap some of the re-emitted heat, keeping the surface temperature regulated and suitable for sustaining life. Although the greenhouse effect is natural, some evidence indicates that human activities are producing increased levels of some greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Scientists believe that the combustion of fossil fuels is

  10. Atmospheric radiation measurement program facilities newsletter, April 2001.; TOPICAL

    International Nuclear Information System (INIS)

    Intensive Observation Period Projects Scheduled-Several IOP projects have been scheduled for the SGP CART site this spring. These projects either have already begun or will begin shortly. Radiosondes-The RS-90 Transition IOP is currently under way. The RS-90 model radiosonde is gradually replacing the older RS-80 model. Radiosondes are instrument packages attached to and launched by weather balloons. The instruments measure atmospheric pressure, temperature, and relative humidity as the balloon rises through the air. The new RS-90 model is a high-performance radiosonde with fast-response sensors capable of providing data for each variable every second. The relatively environmentally friendly package is constructed of cardboard and steel rather than Styrofoam, and it has a water-activated battery that contains no toxic substances. The RS-90 Transition IOP is taking place during April. Operators will launch both the old RS-80 and the new RS-90 radiosondes simultaneously once each day to obtain duplicate vertical profiles of the atmosphere for comparison. This procedure will also allow data users to test the output from the old and new radiosondes in models. Narrow Field of View (NFOV) Solar Spectrometer Cloud Optical Depth Retrieval Campaign-The NFOV IOP is scheduled to take place on May 7-August 31, 2001. A researcher from Pennsylvania State University will be deploying a dual-spectrometer instrument that measures the hemispheric flux and zenith NFOV radiance over a wavelength range of 300- 1000 nanometers. (One nanometer equals 1 billionth of a meter or 0.000000039 inches.) This wavelength range includes the ultraviolet, visible, and near-infrared spectra. These measurements are used to estimate cloud optical depth-a quantity related to the amount of solar radiation intercepted by a cloud-for broken cloud fields over vegetated surfaces. The IOP measurements will be compared with optical depth measurements made by SGP instruments. Precision Gas Sampling (PGS

  11. Atmospheric Radiation Measurement Climate Research Facility (ACRF) Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    LR Roeder

    2007-12-01

    This annual report describes the purpose and structure of the program, and presents key accomplishments in 2007. Notable achievements include: • Successful review of the ACRF as a user facility by the DOE Biological and Environmental Research Advisory Committee. The subcommittee reinforced the importance of the scientific impacts of this facility, and its value for the international research community. • Leadership of the Cloud Land Surface Interaction Campaign. This multi-agency, interdisciplinary field campaign involved enhanced surface instrumentation at the ACRF Southern Great Plains site and, in concert with the Cumulus Humilis Aerosol Processing Study sponsored by the DOE Atmospheric Science Program, coordination of nine aircraft through the ARM Aerial Vehicles Program. • Successful deployment of the ARM Mobile Facility in Germany, including hosting nearly a dozen guest instruments and drawing almost 5000 visitors to the site. • Key advancements in the representation of radiative transfer in weather forecast models from the European Centre for Medium-Range Weather Forecasts. • Development of several new enhanced data sets, ranging from best estimate surface radiation measurements from multiple sensors at all ACRF sites to the extension of time-height cloud occurrence profiles to Niamey, Niger, Africa. • Publication of three research papers in a single issue (February 2007) of the Bulletin of the American Meteorological Society.

  12. Atmospheric Radiation Measurement program (ARM) -- Summer 1995 review

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, G.; Ruderman, M.; Treiman, S.

    1995-10-01

    ARM is a highly focused program designed to improve the understanding of the transport of infrared and solar radiation through the atmosphere. The program pays particular attention to the interaction of radiation with the three phases of water. The goals of ARM are usually articulated in terms of improvements in climate models. The authors agree that ARM can indeed make significant contributions to the understanding of climate change. In addition the authors believe that the results of the program will have wide applicability to a broad range of problems, including more accurate short-term and seasonal weather forecasting. This report examines the issues of anomalous atmospheric absorption and makes recommendations concerning future directions for the ARM program.

  13. Atmospheric Radiation Measurement Program facilities newsletter, July 2001.; TOPICAL

    International Nuclear Information System (INIS)

    Global Warming and Methane-Global warming, an increase in Earth's near-surface temperature, is believed to result from the buildup of what scientists refer to as ''greenhouse gases.'' These gases include water vapor, carbon dioxide, methane, nitrous oxide, ozone, perfluorocarbons, hydrofluoro-carbons, and sulfur hexafluoride. Greenhouse gases can absorb outgoing infrared (heat) radiation and re-emit it back to Earth, warming the surface. Thus, these gases act like the glass of a greenhouse enclosure, trapping infrared radiation inside and warming the space. One of the more important greenhouse gases is the naturally occurring hydrocarbon methane. Methane, a primary component of natural gas, is the second most important contributor to the greenhouse effect (after carbon dioxide). Natural sources of methane include wetlands, fossil sources, termites, oceans, fresh-waters, and non-wetland soils. Methane is also produced by human-related (or anthropogenic) activities such as fossil fuel production, coal mining, rice cultivation, biomass burning, water treatment facilities, waste management operations and landfills, and domesticated livestock operations (Figure 1). These anthropogenic activities account for approximately 70% of the methane emissions to the atmosphere. Methane is removed naturally from the atmosphere in three ways. These methods, commonly referred to as sinks, are oxidation by chemical reaction with tropospheric hydroxyl ion, oxidation within the stratosphere, and microbial uptake by soils. In spite of their important role in removing excess methane from the atmosphere, the sinks cannot keep up with global methane production. Methane concentrations in the atmosphere have increased by 145% since 1800. Increases in atmospheric methane roughly parallel world population growth, pointing to anthropogenic sources as the cause (Figure 2). Increases in the methane concentration reduce Earth's natural cooling efficiency by trapping more of the outgoing

  14. Measurements and theoretical calculations of diffused radiation and atmosphere lucidity

    International Nuclear Information System (INIS)

    Align with other environment friendly renewable energy sources solar energy is widely used in the world. Also in Latvia solar collectors are used. However, in Latvia because of its geographical and climatic conditions there are some specific features in comparison with traditional solar energy using countries. These features lead to the necessity to pay more attention to diffused irradiance. Another factor affecting the received irradiance of any surface is lucidity of atmosphere. This factor has not been studied in Latvia yet. This article deals with evaluation of diffused irradiance, and also of lucidity of atmosphere. The diffused irradiance can be measured directly or as a difference between the global irradiance and the beam one. The lucidity of atmosphere can be calculated from the measurements of both global and beam irradiance, if the height of the sun is known. Therefore, measurements of both global and beam irradiance have been carried out, and the diffused irradiance calculated as a difference between the global irradiance and the beam one. For measuring of the global irradiance the dome solarimeter has been used. For measuring of the direct irradiance tracking to sun pirheliometer has been used. The measurements were performed in Riga from October 2008 till March 2009. The measurements were executed automatically after every 5 minutes. The obtained results have been analyzed taking into account also the data on nebulosity from the State agency Latvian Environment, Geology and Meteorology Agency. Also efforts to calculate theoretically the diffused irradiance from the height of the sun and the data of the nebulosity have been done. These calculated values have been compared with the measured ones. Good accordance is obtained. (author)

  15. Atmospheric Radiation Measurement program climate research facility operations quarterly report.

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, D. L.; Decision and Information Sciences

    2006-09-06

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year dating back to 1998. The U.S. Department of Energy requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1-(ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the third quarter for the Southern Great Plains (SGP) site is 2,074.80 hours (0.95 x 2,184 hours this quarter). The OPSMAX for the North Slope Alaska (NSA) locale is 1,965.60 hours (0.90 x 2,184), and that for the Tropical Western Pacific (TWP) locale is 1,856.40 hours (0.85 x 2,184). The OPSMAX time for the ARM Mobile Facility (AMF) is 2,074.80 hours (0.95 x 2,184). The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or data stream. Data availability reported here refers to the average of the individual, continuous data streams that have been received by the Archive. Data not at the Archive are caused by downtime (scheduled or unplanned) of the individual instruments. Therefore, data availability is directly related to individual instrument uptime. Thus, the average percent of data in the Archive

  16. Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

    International Nuclear Information System (INIS)

    The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth's atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy's Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described

  17. Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

    Energy Technology Data Exchange (ETDEWEB)

    Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.; Wasmer, F.; Pentecost, E.D.

    1992-03-01

    The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climate change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.

  18. The possible direct use of satellite radiance measurements by the Atmospheric Radiation Measurement Program

    International Nuclear Information System (INIS)

    The Atmospheric Radiation Measurement (ARM) Program is a major research program initiated by the Department of Energy to improve our understanding of radiative and cloud processes critical to predicting the Earth's climate and its changes. Central to this concept is the use of four to six intensively instrumented sites for long-term study and characterization of the processes of interest. The instrumentation suites will include ground-based, high-accuracy radiometers for measuring the short and longwave surface flux, as well as an extensive set of ground-and air-based instrumentation for characterizing the intervening atmospheric column. Satellite-based measurements are expected to play a very important role in providing top-of-the-atmosphere measurements. In this study, we examine the possibility of comparing ARM outputs directly with satellite measurements, thereby ensuring the independence of these two important data sets. Thus we focused on what do satellites really measure and how well do they measure it. On what can we do about the general lack of adequate visible channel calibration. On what is the best way for ARM to obtain near-real-time access to this unprocessed data. And on what is the optimum way for ARM to make use of satellite data

  19. Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models

    International Nuclear Information System (INIS)

    The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and related models. The importance of the ARM program is a apparent from the results of model assessments of the impact on global climate change. Recent studies suggest that radiatively active trace gas emissions caused by human activity can lead to a global warming of 1.5 to 4.5 degrees Celsius and to important changes in water availability during the next century (Cess, et al. 1989). These broad-scale changes can be even more significant at regional levels, where large shifts in temperature and precipitation patterns are shown to occur. However, these analyses also indicate that considerable uncertainty exists in these estimates, with the manner in which cloud radiative processes are parameterized among the most significant uncertainty. Thus, although the findings have significant policy implications in assessment of global and regional climate change, their uncertainties greatly influence the policy debate. ARM's highly focused observational and analytical research is intended to accelerate improvements and reduce key uncertainties associated with the way in which GCMs treat cloud cover and cloud characteristics and the resulting radiative forcing. This paper summarizes the scientific context for ARM, ARM's experimental approach, and recent activities within the ARM program

  20. Atmospheric Radiation Measurement program facilities newsletter, April 2002.; TOPICAL

    International Nuclear Information System (INIS)

    The National Oceanic and Atmospheric Administration (NOAA) recently announced the development of El Nino conditions in the tropical Pacific Ocean near the South American coastline. Scientists detected a 4 F increase in the sea-surface temperatures during February. Conrad C. Lautenbacher, NOAA administrator and Under Secretary of Commerce for Oceans and Atmosphere, indicated that this warming is a sign that the Pacific Ocean is heading toward an El Nino condition. Although it is too early to predict how strong the El Nino will become or the conditions it will bring to the United States, Lautenbacher said that the country is likely to feel the effects as soon as midsummer (Figure 1). During the last El Nino in 1997-1998, the United States experienced strong weather impacts. Even though researchers don't understand what causes the onset of El Nino, they do recognize what to expect once development has begun. Scientists can monitor the development of El Nino through NOAA's advanced global climate monitoring system of polar-orbiting satellites and 72 ocean buoys moored across the equator in the Pacific Ocean. The resulting measurements of surface meteorological parameters and upper ocean temperatures are made available to scientists on a real-time basis, allowing for timely monitoring and predictions. This complex monitoring array enabled NOAA to predict the 1997-1998 El Nino six months in advance

  1. Surface shortwave aerosol radiative forcing during the Atmospheric Radiation Measurement Mobile Facility deployment in Niamey, Niger

    Science.gov (United States)

    McFarlane, S. A.; Kassianov, E. I.; Barnard, J.; Flynn, C.; Ackerman, T. P.

    2009-07-01

    The Atmospheric Radiation Measurement (ARM) Program's Mobile Facility (AMF) was deployed to Niamey, Niger, during 2006. Niamey, which is located in sub-Saharan Africa, is affected by both dust and biomass burning emissions. Column aerosol optical properties were derived from multifilter rotating shadowband radiometer, measurements and the vertical distribution of aerosol extinction was derived from a micropulse lidar during the two observed dry seasons (January-April and October-December). Mean aerosol optical depth (AOD) and single scattering albedo (SSA) at 500 nm during January-April were 0.53 ± 0.4 and 0.94 ± 0.05, while during October-December mean AOD and SSA were 0.33 ± 0.25 and 0.99 ± 0.01. Aerosol extinction profiles peaked near 500 m during the January-April period and near 100 m during the October-December period. Broadband shortwave surface fluxes and heating rate profiles were calculated using retrieved aerosol properties. Comparisons for noncloudy periods indicated that the remote sensing retrievals provided a reasonable estimation of the aerosol optical properties, with mean differences between calculated and observed fluxes of less than 5 W m-2 and RMS differences less than 25 W m-2. Sensitivity tests showed that the observed fluxes could be matched with variations of aerosol radiative forcing (ARF) was -21.1 ± 14.3 W m-2 and was estimated to account for 80% of the total radiative forcing at the surface. The ARF was larger during January-April (-28.5 ± 13.5 W m-2) than October-December (-11.9 ± 8.9 W m-2).

  2. Analysis of the effects of aerosol distribution in the atmosphere on surface radiative measurements

    International Nuclear Information System (INIS)

    The distribution of atmospheric aerosols in the atmosphere may have important effects on the radiative properties of the atmosphere and thereby on the climate. The Atmospheric and Geophysical Sciences Division of the Lawrence Livermore National Laboratory is working with the Atmospheric Radiation Measurements (ARM) program to advise the program as to the importance of aerosols to the ARM measurement plan. The ARM Program had established a set of goals which highlight the important areas of scientific needs associated with the understanding and prediction of global climate change. This report summarizes the initial studies performed to assess the importance and effects of atmospheric aerosols on the measurements of atmospheric radiation. To accomplish this, three interlinked models were employed which calculated the MIE parameters, averaged over the appropriate size distributions and computed the solar radiation at the surface. These models are discussed. A number of computations were performed using different aerosol scenarios and size distributions. These results are discussed and a summary of these initial calculations and future directions of research are outlined

  3. Return glider radiosonde to measure temperature, humidity and radiation profiles through the atmosphere

    Science.gov (United States)

    Kraeuchi, Andreas; Philipona, Rolf

    2015-04-01

    Very promising radiation profile measurements through the atmosphere were made in 2011 with a balloon borne short- and longwave net radiometer. New and improved radiation sensors from Kipp&Zonen are now used in a glider aircraft together with a standard Swiss radiosonde from Meteolabor AG. This new return glider radiosonde (RG-R), is lifted up with double balloon technique to prevent pendulum motion and to keep the radiation instruments as horizontal as possible during the ascent measuring phase. The RG-R is equipped with a mechanism that allows to release the radiosonde at a preset altitude, and an autopilot allowing to fly the radiosonde back to the launch site and to land it savely with a parachute at a preset location. The return glider radiosonde technique as well as new measurement possibilities will be shown. First measurements show temperature, humidity and radiation profiles through the atmosphere up to 30 hPa (24 km) during different atmospheric conditions. Radiation profiles during different daytimes show possibilities with respect to temporal resolution of vertical radiation profiles trough the atmosphere.

  4. Atmospheric Radiation Measurement Program facilities newsletter, February 2001.; TOPICAL

    International Nuclear Information System (INIS)

    This newsletter consists of the following: (1) ARM Science Team Meeting Scheduled-The 11th Annual ARM Science Team meeting is scheduled for March 19-23, 2001, in Atlanta, Georgia. Members of the science team will exchange research results achieved by using ARM data. The science team is composed of working groups that investigate four topics: instantaneous radiative flux, cloud parameterizations and modeling, cloud properties, and aerosols. The annual meeting brings together the science team's 150 members to discuss issues related to ARM and its research. The members represent universities, government laboratories and research facilities, and independent research companies. (2) Communications to Extended Facilities Upgraded-New communications equipment has been installed at all of the SGP extended facilities. Shelters were installed to house the new equipment used to transfer data from instruments via the Internet to the site data system at the central facility. This upgrade has improved data availability from the extended facilities to 100% and reduced telephone costs greatly. (3) SGP Goes ''Buggy''-Steve Sekelsky, a researcher from the University of Massachusetts, is planning to bring a 95-GHz radar to the SGP central facility for deployment in March-October 2001. The radar will help to identify signals due to insects flying in the air. The ARM millimeter cloud radar, which operates at 35 GHz, is sensitive to such insect interference. Testing will also be performed by using a second 35-GHz radar with a polarized radar beam, which can differentiate signals from insects versus cloud droplets. (4) Winter Fog-Fog can add to hazards already associated with winter weather. Common types of fog formation include advection, radiation, and steam. Advection fog: An advection fog is a dense fog that forms when a warm, moist air mass moves into an area with cooler ground below. For example, fog can form in winter when warmer, water-saturated air from the south (associated with

  5. Atmospheric Radiation Measurement Climate Research Facility Annual Report 2006

    Energy Technology Data Exchange (ETDEWEB)

    LR Roeder

    2005-11-30

    This annual report describes the purpose and structure of the ARM Climate Research Facility and ARM Science programs and presents key accomplishments in 2006. Noteworthy scientific and infrastructure accomplishments in 2006 include: • Collaborating with the Australian Bureau of Meteorology to lead the Tropical Warm Pool-International Cloud Experiment, a major international field campaign held in Darwin, Australia • Successfully deploying the ARM Mobile Facility in Niger, Africa • Developing the new ARM Aerial Vehicles Program (AVP) to provide airborne measurements • Publishing a new finding on the impacts of aerosols on surface energy budget in polar latitudes • Mitigating a long-standing double-Intertropical Convergence Zone problem in climate models using ARM data and a new cumulus parameterization scheme.

  6. Proceedings of the third Atmospheric Radiation Measurement (ARM) science team meeting

    International Nuclear Information System (INIS)

    This document contains the summaries of papers presented at the 1993 Atmospheric Radiation Measurement (ARM) Science Team meeting held in Morman, Oklahoma. To put these papers in context, it is useful to consider the history and status of the ARM Program at the time of the meeting. Individual papers have been cataloged separately

  7. Atmospheric Radiation Measurement Climate Research Facility (ACRF Instrumentation Status: New, Current, and Future)

    Energy Technology Data Exchange (ETDEWEB)

    JW Voyles

    2008-01-30

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development.

  8. Proceedings of the third Atmospheric Radiation Measurement (ARM) science team meeting

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    This document contains the summaries of papers presented at the 1993 Atmospheric Radiation Measurement (ARM) Science Team meeting held in Morman, Oklahoma. To put these papers in context, it is useful to consider the history and status of the ARM Program at the time of the meeting. Individual papers have been cataloged separately.

  9. Atmospheric radiation measurement program facilities newsletter, August 2001.; TOPICAL

    International Nuclear Information System (INIS)

    Summer 2001 Heat Wave-This summer has proved to be downright hot in the Southern Great Plains states. The temperatures soared to record-setting levels. The state of Oklahoma saw its fourth hottest July since 1895, while Kansas experienced its seventh warmest. The average temperature throughout most of Oklahoma for the month of July was 2.5-5.5 F above normal. The highest temperature recorded in the region during July was 107 F in Oklahoma City. Wichita, Kansas, had 17 July days with recorded temperatures of 100 F or above, while Medicine Lodge, Kansas, had 21. In addition, Oklahoma suffered its ninth driest July, with precipitation levels much below normal. Kansas fared better, receiving above-normal precipitation amounts. Nevertheless, regional July rainfall averaged 1.5-3.0 inches below normal. Not only is a summer heat wave uncomfortable, but it can also be dangerous. The National Weather Service (NWS) has increased efforts to alert the public to the hazards of heat waves. Prolonged excessive heat and humidity stress the human body and can, in some cases, cause death. The NWS has devised a heat index that is a measure of the heat we perceive as a function of air temperature and humidity. A heat index chart displays different zones from caution to extreme danger, much like a wind chill index chart used in the winter. The values represent conditions of light winds and shade. Thus, in full sunshine heat index values can increase by 15 F. Exposure to winds in hot, dry weather can be equally dangerous. The NWS sends out alerts when the heat index is expected to reach values with significant potential impact. The danger of heat-related illness increases with the number of consecutive days with high heat and humidity levels. Heat and humidity take their toll faster on the elderly, small children, and those with respiratory health problems. Heat-related illnesses come in several forms with different symptoms. From common sunburns to heat stroke, these heat disorders

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

    International Nuclear Information System (INIS)

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

  11. Advances in Atmospheric Radiation Measurements and Modeling Needed to Improve Air Safety

    Science.gov (United States)

    Tobiska, W. Kent; Atwell, William; Beck, Peter; Benton, Eric; Copeland, Kyle; Dyer, Clive; Gersey, Brad; Getley, Ian; Hands, Alex; Holland, Michael; Hong, Sunhak; Hwang, Junga; Jones, Bryn; Malone, Kathleen; Meier, Matthias M.; Mertens, Chris; Phillips, Tony; Ryden, Keith; Schwadron, Nathan; Wender, Stephen A.; Wilkins, Richard; Xapsos, Michael A.

    2015-04-01

    Air safety is tied to the phenomenon of ionizing radiation from space weather, primarily from galactic cosmic rays but also from solar energetic particles. A global framework for addressing radiation issues in this environment has been constructed, but more must be done at international and national levels. Health consequences from atmospheric radiation exposure are likely to exist. In addition, severe solar radiation events may cause economic consequences in the international aviation community due to exposure limits being reached by some crew members. Impacts from a radiation environment upon avionics from high-energy particles and low-energy, thermalized neutrons are now recognized as an area of active interest. A broad community recognizes that there are a number of mitigation paths that can be taken relative to the human tissue and avionics exposure risks. These include developing active monitoring and measurement programs as well as improving scientific modeling capabilities that can eventually be turned into operations. A number of roadblocks to risk mitigation still exist, such as effective pilot training programs as well as monitoring, measuring, and regulatory measures. An active international effort toward observing the weather of atmospheric radiation must occur to make progress in mitigating radiation exposure risks. Stakeholders in this process include standard-making bodies, scientific organizations, regulatory organizations, air traffic management systems, aircraft owners and operators, pilots and crew, and even the public.

  12. Measurement and modeling of external radiation during 1984 from LAMPF atmospheric emissions

    International Nuclear Information System (INIS)

    An array of three portable, pressurized ionization chambers (PICs) measured short-term external radiation levels produced by air activation products from the Los Alamos Meson Physics Facility (LAMPF). The monitoring was at the closet offsite location, 700-900 m north and northeast of the source, and across a large, deep canyon. A Gaussian-type atmospheric dispersion model, using onsite meteorological and stack release data, was tested during their study. Monitoring results indicate that a persistent, local up-valley wind during the evening and early morning hours is largely responsible for causing the highest radiation levels to the northeast and north-northeast of LAMPF. Comparison of predicted and measured daily external radiation levels indicates a high degree of correlation. The model also gives accurate estimates of measured concentrations over longer periods of time

  13. Final Technical Report. Cloud and Radiation Testbed (CART) Raman Lidar measurement of atmospheric aerosols for the Atmospheric Radiation Measurement (ARM) Program

    Energy Technology Data Exchange (ETDEWEB)

    Ferrare, Richard A.

    2002-08-19

    Vertical profiles of aerosol extinction are required for determination of the effects of aerosols on the clear-sky radiative flux. Since recent studies have demonstrated the inability to compute these profiles on surface aerosol measurements alone, vertical profiles of aerosol optical properties must be acquired to compute aerosol radiative effects throughout the entire atmospheric column. Following the recommendation of the ARM Aerosol Working Group, the investigator developed, evaluated, and implemented algorithms for the CART Raman Lidar to provide profiles of aerosol extinction and backscattering. By virtue of its ability to measure vertical profiles of both aerosol extinction and water vapor simultaneously in the same scattering volume, we used the resulting profiles from the CART Raman Lidar to investigate the impact of water vapor and relative humidity on aerosol extinction throughout the column on a continuous and routine basis. The investigator used these the CART Raman Lidar aerosol extinction and backscattering profiles to evaluate the vertical variability of aerosol extinction and the extinction/backscatter ratio over the ARM SGP site.

  14. Broadband Outdoor Radiometer Calibration Process for the Atmospheric Radiation Measurement Program

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    The Atmospheric Radiation Measurement program (ARM) maintains a fleet of monitoring stations to aid in the improved scientific understanding of the basic physics related to radiative feedback processes in the atmosphere, particularly the interactions among clouds and aerosols. ARM obtains continuous measurements and conducts field campaigns to provide data products that aid in the improvement and further development of climate models. All of the measurement campaigns include a suite of solar measurements. The Solar Radiation Research Laboratory at the National Renewable Energy Laboratory supports ARM's full suite of stations in a number of ways, including troubleshooting issues that arise as part of the data-quality reviews; managing engineering changes to the standard setup; and providing calibration services and assistance to the full fleet of solar-related instruments, including pyranometers, pyrgeometers, pyrheliometers, as well as the temperature/relative humidity probes, multimeters, and data acquisition systems that are used in the calibrations performed at the Southern Great Plains Radiometer Calibration Facility. This paper discusses all aspects related to the support provided to the calibration of the instruments in the solar monitoring fleet.

  15. Retrieval of atmospheric parameters and radiative properties using Far-Infrared remote sensing measurements

    Science.gov (United States)

    Jamali, Maryam; Milz, Mathias; Martín-Torres, Javier; Palchetti, Luca

    2016-04-01

    The far-infrared (FIR) spectral region, covering wavelengths between 15 μm (667 cm‑1) and about 1 μm (10,000 cm‑1) plays a critical role in the climate system. A good knowledge of the radiation processes in this spectral region is of high interest for observations and understanding of heating and cooling rates, and global energy balance. Even though approximately 50% of terrestrial radiation occurs in the FIR and despite the critical FIR contribution to the Earth's energy balance, this spectral region has been only studied by a few number of instruments. Also the full FIR spectral region has not ever been directly observed from space. High spectral resolution observations in this region can help to enlighten its role for the global energy budget and atmospheric radiation processes. Among others, the reasons for this lack of measurements are: (i) the decreasing intensity of the radiation towards longer wavelengths; and, then (ii) the high sensitivity and cooling of the detectors requirements. These requirements are now overcome and future space missions will have the capability to measure the full FIR and then open fully one-half of the Earth's spectrum, and accordingly improve our ability to model and assess climate processes. The aim of the study is to assess the use of FIR remote sensing instruments for retrievals of atmospheric parameters and radiative properties such as heating and cooling rates. Case studies with simulated spectra, together with ground based measurements in the FIR at Dome C over the Antarctic Plateau at 3,230 m a.s.l. (above sea level) in clear-sky conditions, which been observed almost continuously since 2012, are used to assess the potential of remote sensing instruments in the far-infrared region. Appropriate selection of spectral channels to directly measure the far-infrared spectra as needed for future space missions and recommended.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  17. Proceedings of the second Atmospheric Radiation Measurement (ARM) Science Team Meeting

    International Nuclear Information System (INIS)

    The second Atmospheric Radiation Measurement (ARM) Science Team Meeting was held in Denver, Colorado, in October 1991. The five-day meeting provided a forum for a technical exchange among the members of the ARM Science Team and a discussion of the technical aspects of the project infrastructure. The meeting included several activities: Science Team presentations, discussions of the first site occupation plan, experiment design sessions, and poster sessions. This Proceedings document includes papers presented at the meeting. The papers included are those from the technical sessions, the experiment design sessions, the first site occupation, and descriptions of locales for future sites. Individual projects are processed separately for the database

  18. Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2012-10-10

    Individual datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile research sites are collected and routed to the Data Management Facility (DMF) for processing in near-real-time. Instrument and processed data are then delivered approximately daily to the ARM Data Archive, where they are made freely available to the research community. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Data Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.

  19. Atmospheric Downwelling Longwave Radiation during overcast conditions. Simulations and measurements at Girona, Spain.

    Science.gov (United States)

    Viúdez, Toni; Calbó, Josep; Abel González, Josep; Jiménez, M. Antonia

    2010-05-01

    Clouds play an important role in the terrestrial radiative budget and therefore in the climate change, given their ability to absorb solar radiation and also to absorb and emit longwave radiation toward the space and the terrestrial surface. The study of longwave radiation in presence of clouds can help us to understand better the climatic system, and recognize their importance in the current climate change. Agreement between measurements and simulations can help us to understand much better their radiative behavior. In this study we show a comparison between measurements and calculations using the unidimensional radiative transfer model SBDART (Ricchiazzi et al, 1998) under overcast sky conditions. Measurements were taken from the radiometric and meteorological station at the University of Girona, Spain (41.96 N 2.83 E 110 m a.s.l.). Downward Longwave Radiation, DLR, was measured using a pyrgeometer CG1 by Kipp & Zonen. To determine the cloud fraction, and subsequently select overcast cases, we used the algorithm APCADA (Dürr and Philipona, 2004) from one year dataset of measurements of DLR, temperature and relative humidity. DLR has a strong dependence on atmospheric vertical profiles (mainly on temperature and water vapor content). Since there are no soundings available at the same site, we used the vertical profile from a gridded analysis (provided by the European Centre for Medium-Range Weather Forecasts,ECMWF). Cloud base height (CBH) was included into calculations by using the measurements taken by a ceilometer CL31 by Vaisala. This CBH was compared with an estimation based on ECMWF profiles, setting the cloud base where the relative humidity is higher than a threshold of 95% (RH95). The effective radius of cloud droplets and liquid water path was fixed from typical values (Stephens, 1978). Three different modeling cases were analyzed, depending on the use of the CBH from the ceilometer or from applying the RH95 threshold in ECMWF profiles, and also

  20. The Atmospheric Radiation Measurement Program and interfaces with external data sources

    International Nuclear Information System (INIS)

    The Atmospheric Radiation Measurement (ARM) Program is the Department of Energy's major field project in support of its global change research program. Its objective is to improve the performance of cloud and radiation models and parameterizations in general circulation models (GCMs) used for climate research. The data produced by ARM will be handled and maintained to satisfy the research needs of the program and to be accessible and usable by the general research and academic communities. In addition to data from field instrumentation, ARM Science Team needs include a substantial amount of data from outside the ARM Program (''external data''), which will be acquired and provided routinely through the ARM data system. With respect to data archival and sharing, the ARM Program reflects the objectives delineated by the US Global Change. The purpose of this presentation is to summarize the conceptual designs embodied in the ARM data system and the status of its implementation

  1. Atmospheric Radiation Measurement Program Science Plan. Current Status and Future Directions of the ARM Science Program

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, Thomas P.; Del Genio, Anthony D.; Ellingson, Robert G.; Ferrare, Richard A.; Klein, Steve A.; McFarquhar, Gregory M.; Lamb, Peter J.; Long, Charles M.; Verlinde, Johannes

    2004-10-30

    The Atmospheric Radiation Measurement (ARM) Program has matured into one of the key programs in the U.S. Climate Change Science Program. The ARM Program has achieved considerable scientific success in a broad range of activities, including site and instrument development, atmospheric radiative transfer, aerosol science, determination of cloud properties, cloud modeling, and cloud parameterization testing and development. The focus of ARM science has naturally shifted during the last few years to an increasing emphasis on modeling and parameterization studies to take advantage of the long time series of data now available. During the next 5 years, the principal focus of the ARM science program will be to: Maintain the data record at the fixed ARM sites for at least the next five years; Improve significantly our understanding of and ability to parameterize the 3-D cloud-radiation problem at scales from the local atmospheric column to the global climate model (GCM) grid square; Continue developing techniques to retrieve the properties of all clouds, with a special focus on ice clouds and mixed-phase clouds; Develop a focused research effort on the indirect aerosol problem that spans observations, physical models, and climate model parameterizations; Implement and evaluate an operational methodology to calculate broad-band heating rates in the atmospheric columns at the ARM sites; Develop and implement methodologies to use ARM data more effectively to test atmospheric models, both at the cloud-resolving model scale and the GCM scale; and, Use these methodologies to diagnose cloud parameterization performance and then refine these parameterizations to improve the accuracy of climate model simulations. In addition, the ARM Program is actively developing a new ARM Mobile Facility (AMF) that will be available for short deployments (several months to a year or more) in climatically important regions. The AMF will have much of the same instrumentation as the remote

  2. INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

    OpenAIRE

    Alexandru Dan Toma

    2013-01-01

    The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categ...

  3. Atmospheric Radiative Transfer

    Science.gov (United States)

    Perliski, Lori

    Because radiative transfer cuts across many scientific disciplines with applications including remote sensing, climate, atmospheric chemistry, and photobiology, there is a need for comprehensive books on this subject that can appeal to a wide readership. While Atmospheric Radiative Transfer takes strides toward filling this niche by addressing a broad range of topics, it is dry reading and suffers from lack of detail. The book was based on a graduate-level course taught at the University of Sciences and Technologies in Lille, France, and indeed, the text reads much like an expanded outline perhaps derived from lecture notes.Part one deals with general radiative transfer, and part two covers Earth's radiation budget, the climate system, and remote sensing techniques. The radiative transfer equation and solutions for absorbing and scattering atmospheres are discussed as are the details of absorption, such as energy levels, line strengths, line intensities, equivalent widths, and weak- and strong-line limits.

  4. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report July 1 – September 30, 2009

    Energy Technology Data Exchange (ETDEWEB)

    DL Sisterson

    2009-10-15

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data then are sent approximately daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by 1) individual data stream, site, and month for the current year and 2) site and fiscal year (FY) dating back to 1998.

  5. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report April 1 - June 30, 2008

    Energy Technology Data Exchange (ETDEWEB)

    DL Sisterson

    2008-06-01

    Description. Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.

  6. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report July 1 – September 30, 2006

    Energy Technology Data Exchange (ETDEWEB)

    DL Sisterson

    2006-10-01

    Description. Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year dating back to 1998.

  7. Atmospheric Radiation Measurement Climate Research Facility Operations Quarterly Report July 1–September 30, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, JW

    2011-10-10

    Individual raw datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ARM Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of processed data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.

  8. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report - July 1 - September 30, 2008

    Energy Technology Data Exchange (ETDEWEB)

    DL Sisterson

    2008-09-30

    Description. Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.

  9. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report April 1 – June 30, 2006

    Energy Technology Data Exchange (ETDEWEB)

    DL Sisterson

    2006-07-01

    Description. Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year; and (2) site and fiscal year dating back to 1998.

  10. Data management and scientific integration within the Atmospheric Radiation Measurement Program

    Science.gov (United States)

    Gracio, Deborah K.; Hatfield, Larry D.; Yates, Kenneth R.; Voyles, Jimmy W.; Tichler, Joyce L.; Cederwall, Richard T.; Laufersweiler, Mark J.; Leach, Martin J.; Singley, Paul

    1995-01-01

    The Atmospheric Radiation Measurement (ARM) Program has been developed by the U.S. Department of Energy with the goal to improve the predictive capabilities of General Circulation Models (GCM's) in their treatment of clouds and radiative transfer effects. To achieve this goal, three experimental testbeds were designed for the deployment of instruments that will collect atmospheric data used to drive the GCM's. Each site, known as a Cloud and Radiation Testbed (CART), consists of a highly available, redundant data system for the collection of data from a variety of instrumentation. The first CART site was deployed in April 1992 in the Southern Great Plains (SGP), Lamont, Oklahoma, with the other two sites to follow in September 1995 in the Tropical Western Pacific and in 1997 on the North Slope of Alaska. Approximately 400 MB of data are transferred per day via the Internet from the SGP site to the ARM Experiment Center at Pacific Northwest Laboratory in Richland, Washington. The Experiment Center is central to the ARM data path and provides for the collection, processing, analysis, and delivery of ARM data. Data are received from the CART sites from a variety of instrumentation, observational systems, amd external data sources. The Experiment Center processes these data streams on a continuous basis to provide derived data products to the ARM Science Team in near real-time while providing a three-month running archive of data. A primary requirement of the ARM Program is to preserve and protect all data produced or acquired. This function is performed at Oak Ridge National Laboratory where leading edge technology is employed for the long-term storage of ARM data. The ARM Archive provides access to data for participation outside of the ARM Program. The ARM Program involves a collaborative effort by teams from various DOE National Laboratories, providing multi-disciplinary areas of expertise. This paper will discuss the collaborative methods in which the ARM teams

  11. Proceedings of the sixth Atmospheric Radiation Measurement (ARM) Science Team meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    This document contains the summaries of papers presented at the 1996 Atmospheric Radiation Measurement (ARM) Science Team meeting held at San Antonio, Texas. The history and status of the ARM program at the time of the meeting helps to put these papers in context. The basic themes have not changed. First, from its beginning, the Program has attempted to respond to the most critical scientific issues facing the US Global Change Research Program. Second, the Program has been strongly coupled to other agency and international programs. More specifically, the Program reflects an unprecedented collaboration among agencies of the federal research community, among the US Department of Energy`s (DOE) national laboratories, and between DOE`s research program and related international programs, such as Global Energy and Water Experiment (GEWEX) and the Tropical Ocean Global Atmosphere (TOGA) program. Next, ARM has always attempted to make the most judicious use of its resources by collaborating and leveraging existing assets and has managed to maintain an aggressive schedule despite budgets that have been much smaller than planned. Finally, the Program has attracted some of the very best scientific talent in the climate research community and has, as a result, been productive scientifically.

  12. Absorption of solar radiation by the atmosphere as determined using satellite, aircraft, and surface data during the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE)

    International Nuclear Information System (INIS)

    Data sets acquired during the Atmospheric Radiation Measurement Enhanced Shortwave Experiment (ARESE) using simultaneous measurements from five independent platforms (GOES 8 geostationary satellite, ER-2, Egrett and Twin Otter aircraft, and surface) are analyzed and compared. A consistent data set can be built for selected days during ARESE on the basis of the observations from these platforms. The GOES 8 albedos agree with the ER 2, Egrett, and Twin Otter measured instantaneous albedos within 0.013±0.016, 0.018±0.032, and 0.006±0.011, respectively. It is found that for heavy overcast conditions the aircraft measurements yield an absorptance of 0.32±0.03 for the layer between the aircraft (0.5-13 km), while the GOES 8 albedo versus surface transmittance analysis gives an absorptance of 0.33±0.04 for the total atmosphere (surface to top). The absorptance of solar radiation estimated by model calculations for overcast conditions varies between 0.16 and 0.24, depending on the model used and on cloud and aerosol implementation. These results are in general agreement with recent findings for cloudy skies, but here a data set that brings together independent simultaneous observations (satellite, surface, and aircraft) is used. Previous ARESE results are reexamined in light of the new findings, and it is concluded that the overcast absorptance in the 0.224-0.68 μm spectral region ranges between 0.04±0.06 and 0.08±0.06, depending on the particular case analyzed. No evidence of excess clear-sky absorption beyond model and experimental errors is found. (c) 2000 American Geophysical Union

  13. Atmospheric dispersion of argon-41 from anuclear research reactor: measurement and modeling of plume geometry and gamma radiation field

    DEFF Research Database (Denmark)

    Lauritzen, Bent; Astrup, Poul; Drews, Martin; Jørgensen, Hans; Mikkelsen, Torben; Thykier-Nielsen, Søren; Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim; Rojas-Palma, Carlos; Van Ammel, Raf

    2003-01-01

    An atmospheric dispersion experiment was conducted using a visible tracer along with the routine release of argon-41 from the BR1 research reactor in Mol, Belgium. Simultaneous measurements of plume geometry and radiation fields for argon-41 decay were performed as well as measurements of the argon...

  14. Single-column data assimilation for the Atmospheric Radiation Measurement (ARM) Program

    International Nuclear Information System (INIS)

    The main purpose of the ARM program is to provide the necessary data to develop, test and validate the parameterization of clouds and of their interactions with the radiation field, and the computation of radiative transfer in climate models. For various reasons, much of the ARM observations will be imperfect, incomplete, redundant, indirect and unrepresentative. Various techniques of data assimilation have been developed to deal with these problems. The variational data assimilation and adjoint method applied to a single column model is described here. A model is used to simulate the evolution of the atmosphere during an assimilation period. As the model is run, a cost function is computed which is essentially a measure of simulation errors. The method then consists in adjusting some model parameters to minimize the cost function. Optimization of the model parameters needs to be done with a much longer series of data, to cover different meteorological situations. Once parameters are set, nudging terms are used as control variables. The Derber nudging method will require considerable tuning, especially in defining the vertical profiles of the nudging terms. Extensive tests are currently underway of both model optimization and data assimilation

  15. The Atmospheric radiation measurement (ARM program network of microwave radiometers: instrumentation, data, and retrievals

    Directory of Open Access Journals (Sweden)

    M. P. Cadeddu

    2013-09-01

    Full Text Available The Climate Research Facility of the US Department of Energy's Atmospheric Radiation Measurement (ARM Program operates a network of ground-based microwave radiometers. Data and retrievals from these instruments have been available to the scientific community for almost 20 yr. In the past five years the network has expanded to include a total of 22 microwave radiometers deployed in various locations around the world. The new instruments cover a frequency range between 22 and 197 GHz and are consistently and automatically calibrated. The latest addition to the network is a new generation of three-channel radiometers, currently in the early stage of deployment at all ARM sites. The network has been specifically designed to achieve increased accuracy in the retrieval of precipitable water vapor (PWV and cloud liquid water path (LWP with the long-term goal of providing the scientific community with reliable, calibrated radiometric data and retrievals of important geophysical quantities with well-characterized uncertainties. The radiometers provide high-quality, continuous datasets that can be utilized in a wealth of applications and scientific studies. This paper presents an overview of the microwave instrumentation, calibration procedures, data, and retrievals that are available for download from the ARM data archive.

  16. The Atmospheric Radiation Measurement (ARM program network of microwave radiometers: instrumentation, data, and retrievals

    Directory of Open Access Journals (Sweden)

    M. P. Cadeddu

    2013-04-01

    Full Text Available The Climate Research Facility of the US Department of Energy's Atmospheric Radiation Measurement (ARM Program operates a network of ground-based microwave radiometers. Data and retrievals from these instruments have been available to the scientific community for almost 20 yr. In the past five years the network has been expanded to include a total of 22 microwave radiometers deployed in various locations around the world. The new instruments cover a frequency range between 22 and 197 GHz and are consistently and automatically calibrated. The latest addition to the network is a new generation of three-channel radiometers currently in the early stage of deployment at all ARM sites. The network has been specifically designed to achieve increased accuracy in the retrieval of precipitable water vapor (PWV and cloud liquid water path (LWP with the long-term goal of providing the scientific community with reliable, calibrated radiometric data and retrievals of important geophysical quantities with well-characterized uncertainties. The radiometers provide high-quality, continuous datasets that can be utilized in a wealth of applications and scientific studies. This paper presents an overview of the microwave instrumentation, calibration procedures, data, and retrievals that are available for download from the ARM data archive.

  17. Different atmospheric parameters influence on spectral UV radiation (measurements and modelling)

    Energy Technology Data Exchange (ETDEWEB)

    Chubarova, N.Y. [Moscow State Univ. (Russian Federation). Meteorological Observatory; Krotkov, N.A. [Maryland Univ., MD (United States). JCESS/Meteorology Dept.; Geogdzhaev, I.V.; Bushnev, S.V.; Kondranin, T.V. [SUMGF/MIPT, Dolgoprudny (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Dolgoprudny (Russian Federation)

    1995-12-31

    The ultraviolet (UV) radiation plays a vital role in the biophysical processes despite its small portion in the total solar flux. UV radiation is subject to large variations at the Earth surface depending greatly on solar elevation, ozone and cloud amount, aerosols and surface albedo. The analysis of atmospheric parameters influence is based on the spectral archive data of three spectral instruments: NSF spectroradiometer (Barrow network) (NSF Polar Programs UV Spectroradiometer Network 1991-1992,1992), spectrophotometer (SUVS-M) of Central Aerological Observatory CAO, spectroradiometer of Meteorological Observatory of the Moscow State University (MO MSU) and model simulations based on delta-Eddington approximation

  18. Can Top-of-Atmosphere Radiation Measurements Constrain Climate Predictions? Part I: Tuning

    OpenAIRE

    Simon F. B. Tett; Mineter, Michael J.; Cartis, Coralia; Rowlands, Daniel J.; Liu, Ping

    2013-01-01

    Perturbed physics configurations of version 3 of the Hadley Centre Atmosphere Model (HadAM3) driven with observed sea surface temperatures (SST) and sea ice were tuned to outgoing radiation observations using a Gauss-Newton line search optimization algorithm to adjust the model parameters. Four key parameters that previous research found affected climate sensitivity were adjusted to several different target values including two sets of observations. The observations used were the global avera...

  19. Atmospheric radiation flight dose rates

    Science.gov (United States)

    Tobiska, W. K.

    2015-12-01

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

  20. Direct Measure of Radiative and Dynamical Properties of an Exoplanet Atmosphere

    CERN Document Server

    de Wit, Julien; Langton, Jonathan; Laughlin, Gregory; Deming, Drake; Batygin, Konstantin; Fortney, Jonathan J

    2016-01-01

    Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can illuminate how a planet's atmosphere responds to changes in incident flux. We report here the analysis of multi-day multi-channel photometry of the eccentric (e~ 0.93) hot Jupiter HD 80606 b obtained with the Spitzer Space Telescope. The planet's extreme eccentricity combined with the long coverage and exquisite precision of new periastron-passage observations allow us to break the degeneracy between the radiative and dynamical timescales of HD 80606 b's atmosphere and constrain its global thermal response. Our analysis reveals that the atmospheric layers probed heat rapidly (~4 hr radiative timescale) from $\\lt$500 to 1400 K as they absorb ~ 20% of the incoming stellar flux during the periastron passage, while the planet's rotation period is 93$\\pm_{35}^{85}$ hr, which exceeds the predicted ...

  1. Direct Measure of Radiative and Dynamical Properties of an Exoplanet Atmosphere

    Science.gov (United States)

    de Wit, Julien; Lewis, Nikole K.; Langton, Jonathan; Laughlin, Gregory; Deming, Drake; Batygin, Konstantin; Fortney, Jonathan J.

    2016-04-01

    Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can illuminate how a planet’s atmosphere responds to changes in incident flux. We report here the analysis of multi-day multi-channel photometry of the eccentric (e∼ 0.93) hot Jupiter HD 80606 b obtained with the Spitzer Space Telescope. The planet’s extreme eccentricity combined with the long coverage and exquisite precision of new periastron-passage observations allow us to break the degeneracy between the radiative and dynamical timescales of HD 80606 b’s atmosphere and constrain its global thermal response. Our analysis reveals that the atmospheric layers probed heat rapidly (∼4 hr radiative timescale) from \\lt 500 to 1400 K as they absorb ∼ 20% of the incoming stellar flux during the periastron passage, while the planet’s rotation period is {93}-35+85 hr, which exceeds the predicted pseudo-synchronous period (40 hr).

  2. Atmospheric Radiation Measurement program climate research facility operations quarterly report July 1 - September 30, 2008.

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, D. L.

    2008-10-08

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. Table 1 shows the accumulated maximum operation time (planned uptime), actual hours of operation, and variance (unplanned downtime) for the period July 1 - September 30, 2008, for the fixed sites. The AMF has been deployed to China, but the data have not yet been released. The fourth quarter comprises a total of 2,208 hours. The average exceeded our goal this quarter. The Site Access Request System is a web-based database used to track visitors to the fixed and mobile sites, all of which have facilities that can be visited. The NSA locale has the Barrow and Atqasuk sites. The SGP site has a central facility, 23 extended facilities, 4 boundary facilities, and 3 intermediate facilities. The TWP locale has the Manus, Nauru, and Darwin sites. HFE represents the AMF statistics for the Shouxian, China, deployment in 2008. FKB represents the AMF statistics for the Haselbach, Germany, past deployment in 2007. NIM represents the AMF statistics for the Niamey, Niger, Africa, past deployment in 2006. PYE represents just the AMF Archive statistics for the Point Reyes, California, past deployment in 2005. In addition, users who do not want to wait for data to be provided through the ACRF Archive can request a research account on the local site data system. The seven computers for the

  3. The Zugspitze radiative closure experiment: quantification of the near-infrared water vapor continuum from atmospheric measurements

    Science.gov (United States)

    Reichert, Andreas; Sussmann, Ralf; Rettinger, Markus

    2016-04-01

    Inaccuracies in the description of atmospheric radiative processes are among the major shortcomings of current climate models. Especially the contribution by water vapor, the primary greenhouse gas in the Earth's atmosphere, currently still lacks sufficiently accurate quantification. The main focus of our study is on the so-called water vapor continuum absorption in the near-infrared spectral range, which is of crucial importance for atmospheric radiative processes. To date, the quantification of this contribution originates exclusively from laboratory experiments which show contradictory results and whose findings are not unambiguously transferable to atmospheric conditions. The aim of the Zugspitze radiative closure study is therefore to obtain, to our knowledge for the first time, an exact characterization of the near-infrared water vapor continuum absorption using atmospheric measurements. This enables validation and, if necessary, improvements of the radiative transfer codes used in current climate models. The closure experiment comprises near-infrared spectral radiance measurements using a solar absorption FTIR spectrometer. These measurements are then compared to synthetic radiance spectra computed by means of a high-resolution radiative transfer model. The spectral residuals, i.e. the difference between measured and calculated spectral radiances can then be used to quantify errors in the description of water vapor absorption. Due to the extensive permanent instrumentation available at the Zugspitze observatory, the atmospheric state used as an input to the model calculations can be constrained with high accuracy. Additionally, we employ a novel radiometric calibration strategy for the solar FTIR spectral radiance measurements based on a combination of the Langley method and measurements of a medium-temperature blackbody source. These prerequisites enable accurate quantification of the water vapor continuum in the near-infrared spectral region, where

  4. A hierarchical approach to improved cloud radiation parameterization for climate models through the Atmospheric Radiation Measurement Program

    International Nuclear Information System (INIS)

    Improved parameterization of clouds for general circulation models will require both ARM observations and the use of more detailed cloud models. The authors have adopted a parallel implementation approach to improve cloud parameterizations by including identical cloud radiative processes into three models that span the important spatial and temporal scales for cloud research. These models include a one-dimensional detailed ice microphysical model, the Clark cumulus ensemble model, and the Community Climate Model (CCM2) of the National Center for Atmospheric Research (NCAR). The first parallel development effort was to implement a column version of the CCM2 radiation model in the cirrus cloud model and the cumulus ensemble model. The same column model has also been implemented in the cloud microphysics model. The second effort was the introduction of explicit ice radiative properties into the shortwave and longwave radiative transfer model. The dependence of cirrus cloud radiative heating and longwave cooling on the ice particle size has been established as causing changes in zonally averaged temperature and zonal wind

  5. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report July 1 – September 30, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, DL

    2008-09-30

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. The U.S. Department of Energy (DOE) requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1 – (ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the fourth quarter of FY 2008 for the Southern Great Plains (SGP) site is 2,097.60 hours (0.95 x 2,208 hours this quarter). The OPSMAX for the North Slope Alaska (NSA) locale is 1,987.20 hours (0.90 x 2,208), and for the Tropical Western Pacific (TWP) locale is 1,876.80 hours (0.85 x 2,208). The OPSMAX time for the ARM Mobile Facility (AMF) is not reported this quarter because the data have not yet been released from China to the DMF for processing. The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or data stream. Data availability reported here refers to the average of the individual, continuous data streams that have been received by the Archive. Data not at the Archive are caused by downtime (scheduled or unplanned) of the individual instruments. Therefore, data availability is

  6. MAX-DOAS measurements of atmospheric trace gases in Ny-Ålesund - Radiative transfer studies and their application

    Science.gov (United States)

    Wittrock, F.; Oetjen, H.; Richter, A.; Fietkau, S.; Medeke, T.; Rozanov, A.; Burrows, J. P.

    2004-06-01

    A new approach to derive tropospheric concentrations of some atmospheric trace gases from ground-based UV/vis measurements is described. The instrument, referred to as the MAX-DOAS, is based on the well-known UV/vis instruments, which use the sunlight scattered in the zenith sky as the light source and the method of Differential Optical Absorption Spectroscopy (DOAS) to derive column amounts of absorbers like ozone and nitrogen dioxide. Substantial enhancements have been applied to this standard setup to use different lines of sight near to the horizon as additional light sources (MAX - multi axis). Results from measurements at Ny-Ålesund (79° N, 12° E) are presented and interpreted with the full-spherical radiative transfer model SCIATRAN. In particular, measurements of the oxygen dimer O4 which has a known column and vertical distribution in the atmosphere are used to evaluate the sensitivity of the retrieval to parameters such as multiple scattering, solar azimuth, surface albedo and refraction in the atmosphere and also to validate the radiative transfer model. As a first application, measurements of NO2 emissions from a ship lying in Ny-Ålesund harbour are presented. The results of this study demonstrate the feasibility of long term UV/vis multi axis measurement that can be used to derive not only column amounts of different trace gases but also some information on the vertical location of these absorbers.

  7. An improved method of Lambertian CCD-camera radiation flux measurement based on SMARTS (simple model of the atmospheric radiative transfer of sunshine) to reduce spectral errors

    International Nuclear Information System (INIS)

    A Lambertian CCD-camera method is convenient to measure concentrating radiation fluxes, where a crucial factor, a calibration factor, always varies with spectra and brings errors. In this paper, a new calibration method is proposed based on spectral normalization calculation and tries to reduce spectral errors in Lambertian CCD-camera measurement. The calibration factor for AM1.5 is standardized over a transmittance range by matching gray values of photos to readings of calorimeter. A spectrum is calculated by SMARTS (simple model of the atmospheric radiative transfer of sunshine) according to the local time, latitude and longitude. A calibration factor is adjusted by calculated spectral offsets accordingly. Therefore an absolute radiation flux distribution is obtained by a gray value captured by the CCD-camera without calorimeter. Calculated results indicate that spectral irradiance between 700 and 800 nm dominates gray values on the target for solar radiation flux measurement. The offsets are increasing continuously from AM1 to AM5, which are validated by experimental results. The difference between measured and calculated calibration factors is 11%, which fits to the results of error estimate. These indicate that the improved method was feasible and reliable to measure concentrating radiation fluxes easily. - Highlights: • An improved Lambertian CCD-camera radiation measurement method is proposed. • The spectral errors are reduced by the calculated offsets based on SMARTS (simple model of the atmospheric radiative transfer of sunshine). • The absolute radiation flux distributions can be obtained without calorimeter. • The total estimated error for the simulator is ±13.17%. • The results of validation experiment demonstrate an error of 11%

  8. Raman lidar measurements of water vapor and aerosols during the atmospheric radiation measurement (ARM) remote clouds sensing (RCS) intensive observation period (IOP)

    Energy Technology Data Exchange (ETDEWEB)

    Melfi, S.H.; Starr, D.O`C.; Whiteman, D. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)] [and others

    1996-04-01

    The first Atmospheric Radiation Measurement (ARM) remote Cloud Study (RCS) Intensive Operations Period (IOP) was held during April 1994 at the Southern Great Plains (SGP) site. This experiment was conducted to evaluate and calibrate state-of-the-art, ground based remote sensing instruments and to use the data acquired by these instruments to validate retrieval algorithms developed under the ARM program.

  9. Atmospheric Radiation Measurement program climate research facility operations quarterly report July 1 - Sep. 30, 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, D. L.

    2009-10-15

    Individual raw data streams from instrumentation at the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility (ACRF) fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near-real time. Raw and processed data are then sent approximately daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. The U.S. Department of Energy (DOE) requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1 - (ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the fourth quarter of FY 2009 for the Southern Great Plains (SGP) site is 2,097.60 hours (0.95 ? 2,208 hours this quarter). The OPSMAX for the North Slope Alaska (NSA) locale is 1,987.20 hours (0.90 ? 2,208) and for the Tropical Western Pacific (TWP) locale is 1,876.8 hours (0.85 ? 2,208). The ARM Mobile Facility (AMF) was officially operational May 1 in Graciosa Island, the Azores, Portugal, so the OPSMAX time this quarter is 2,097.60 hours (0.95 x 2,208). The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or data stream. Data availability reported here refers to the average of the individual, continuous data streams that have been received by the Archive. Data not at the Archive result from downtime (scheduled or unplanned) of the individual instruments. Therefore, data

  10. Analytical algorithm for modeling polarized solar radiation transfer through the atmosphere for application in processing complex lidar and radiometer measurements

    International Nuclear Information System (INIS)

    Inversion algorithms and program packages recently created for processing data of the ground-based radiometer spectral measurements along with lidar multi-wavelength measurements are extremely multiparametric. Therefore, it is very important to develop an efficient program module for computations of functions modeling measurements by a sun-radiometer in the inversion procedure. In this paper, we present the analytical version of such efficient algorithm and analytical code on C++ designed for performance of algorithm testing. The code computes multiple scattering of the Sun light in the atmosphere. Data output are the radiance and linear polarization parameters angular patterns at a preselected altitude. The atmosphere model with mixed aerosol and molecular scattering is given approximately as the homogeneous atmosphere model. The algorithm testing has been carried out by comparison of computed data with accurate data obtained on the base of the discrete-ordinate code. Errors of estimates of downward radiance above the Earth surface turned out to be within 10%–15%.. The analytical solution construction concept has taken from the scalar task of solar radiation transfer in the atmosphere where an approximate analytical solution was developed. Taking into account the fact that aerosol phase functions are highly forward elongated, the multi-component method of solving vector transfer equations and small-angle approximation have been used. Generalization of the scalar approach to the polarization parameters is described. - Highlights: • We create an analytical algorithm and code to solve direct atmospheric task. • Data-out include a Stokes vector of scattered Sun light in a homogeneous atmosphere. • Solution for radiance involves several rather accurate approximations of scalar theory. • Errors of radiance estimates at the atmosphere bottom are within 10–15%

  11. Atmospheric Radiation Measurement Program Climate Research Facility Operation quarterly report July 1 - September 30, 2010.

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, D. L.

    2010-10-26

    Individual raw datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ARM Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998. The U.S. Department of Energy (DOE) requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1-(ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the fourth quarter of FY2010 for the Southern Great Plains (SGP) site is 2097.60 hours (0.95 2208 hours this quarter). The OPSMAX for the North Slope of Alaska (NSA) locale is 1987.20 hours (0.90 2208) and for the Tropical Western Pacific (TWP) locale is 1876.80 hours (0.85 2208). The first ARM Mobile Facility (AMF1) deployment in Graciosa Island, the Azores, Portugal, continues, so the OPSMAX time this quarter is 2097.60 hours (0.95 x 2208). The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or datastream. Data availability reported here refers to the average of the individual, continuous datastreams that have been received by the Archive. Data not at the Archive are caused by downtime (scheduled or unplanned) of the individual instruments. Therefore, data availability is directly related to

  12. Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

    Directory of Open Access Journals (Sweden)

    B. J. Majestic

    2007-01-01

    Full Text Available In this study, ambient atmospheric particulate matter (PM samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days or short-term transport (1 to 10 days and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1 inductively coupled plasma-mass spectrometry (ICPMS for total iron, 2 x-ray absorbance near edge structure (XANES spectroscopy for the measurement of total Fe(II and Fe(III, and 3 a wet-chemical method to measure soluble Fe(II and Fe(III. Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction of the total iron in the PM is in the form of Fe(III. Fe(III was shown to be a significant fraction of the soluble iron (sometimes > 50%, but the relative significance of Fe(III was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 18% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II/Fe(III content. A slight increase was noted in the coarse (>2.5 μm fraction and a slight decrease in the 0.25 to 0.5 μm fraction. The soluble fraction generally showed (excepting one day a decrease of soluble Fe(II prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II was observed in the super-micron fraction. These results show that changes in the soluble iron fraction occur

  13. Technical progress report: Completion of spectral rotating shadowband radiometers and analysis of atmospheric radiation measurement spectral shortwave data

    Energy Technology Data Exchange (ETDEWEB)

    Michalsky, J.; Harrison, L. [State Univ. of New York, Albany, NY (United States)

    1996-04-01

    Our goal in the Atmospheric Radiation Measurement (ARM) Program is the improvement of radiation models used in general circulation models (GCMs), especially in the shortwave, (1) by providing improved shortwave radiometric measurements for the testing of models and (2) by developing methods for retrieving climatologically sensitive parameters that serve as input to shortwave and longwave models. At the Atmospheric Sciences Research Center (ASRC) in Albany, New York, we are acquiring downwelling direct and diffuse spectral irradiance, at six wavelengths, plus downwelling broadband longwave, and upwelling and downwelling broadband shortwave irradiances that we combine with National Weather Service surface and upper air data from the Albany airport as a test data set for ARM modelers. We have also developed algorithms to improve shortwave measurements made at the Southern Great Plains (SGP) ARM site by standard thermopile instruments and by the multifilter rotating shadowband radiometer (MFRSR) based on these Albany data sets. Much time has been spent developing techniques to retrieve column aerosol, water vapor, and ozone from the direct beam spectral measurements of the MFRSR. Additionally, we have had success in calculating shortwave surface albedo and aerosol optical depth from the ratio of direct to diffuse spectral reflectance.

  14. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report July 1–September 30, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, DL

    2010-10-15

    Individual raw datastreams from instrumentation at the Atmospheric Radiation Measurement (ARM) Climate Research Facility fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at Pacific Northwest National Laboratory (PNNL) for processing in near real-time. Raw and processed data are then sent approximately daily to the ARM Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual datastream, site, and month for the current year and (2) site and fiscal year (FY) dating back to 1998.

  15. Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

    Directory of Open Access Journals (Sweden)

    B. J. Majestic

    2007-01-01

    Full Text Available In this study, ambient atmospheric particulate matter samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days or short-term transport (1 to 10 days and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1 inductively coupled plasma-mass spectrometry (ICPMS for total iron, 2 x-ray absorbance near edge structure (XANES spectroscopy for the measurement of total Fe(II and Fe(III, and 3 a wet-chemical method to measure soluble Fe(II and Fe(III. Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction of the total iron in the PM is in the form of Fe(III. Fe(III was shown to be a significant fraction of the soluble iron (sometimes >50%, but the relative significance of Fe(III was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 20% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II/Fe(III content. A slight increase was noted in the coarse (>2.5 µm fraction and a slight decrease in the 0.25 to 0.5 µm fraction. The soluble fraction generally showed (excepting one day a decrease of soluble Fe(II prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II was observed in the super-micron fraction.

  16. Atmospheric Measurements Laboratory (AML)

    Data.gov (United States)

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

  17. Improvements in Near-Terminator and Nocturnal Cloud Masks using Satellite Imager Data over the Atmospheric Radiation Measurement Sites

    Energy Technology Data Exchange (ETDEWEB)

    Trepte, Q.Z.; Minnis, P.; Heck, P.W.; Palikonda, R.

    2005-03-18

    Cloud detection using satellite measurements presents a big challenge near the terminator where the visible (VIS; 0.65 {micro}m) channel becomes less reliable and the reflected solar component of the solar infrared 3.9-{micro}m channel reaches very low signal-to-noise ratio levels. As a result, clouds are underestimated near the terminator and at night over land and ocean in previous Atmospheric Radiation Measurement (ARM) Program cloud retrievals using Geostationary Operational Environmental Satellite (GOES) imager data. Cloud detection near the terminator has always been a challenge. For example, comparisons between the CLAVR-x (Clouds from Advanced Very High Resolution Radiometer [AVHRR]) cloud coverage and Geoscience Laser Altimeter System (GLAS) measurements north of 60{sup o}N indicate significant amounts of missing clouds from AVHRR because this part of the world was near the day/night terminator viewed by AVHRR. Comparisons between MODIS cloud products and GLAS at the same regions also shows the same difficulty in the MODIS cloud retrieval (Pavolonis and Heidinger 2005). Consistent detection of clouds at all times of day is needed to provide reliable cloud and radiation products for ARM and other research efforts involving the modeling of clouds and their interaction with the radiation budget. To minimize inconsistencies between daytime and nighttime retrievals, this paper develops an improved twilight and nighttime cloud mask using GOES-9, 10, and 12 imager data over the ARM sites and the continental United States (CONUS).

  18. Finite Difference Radiative Transfer Model Calculations Compared to Measurements at the Top and Bottom of the Atmosphere

    Science.gov (United States)

    LeCroy, Stuart R.; Whitlock, Charles H.; Suttles, John T.

    1997-01-01

    A finite difference radiative transfer program was developed to handle most anisotropic scattering and reflectance problems encountered in the Earth's atmospheric system. The model has been used to reproduce the radiance received by both satellite and ground based radiation measuring instruments. It accurately replicates the radiance measured by both narrow and wide field-of-view instruments with either narrow or broadband wavelength ranges located on the surface and at satellite altitudes. The output of the finite difference code is compared to the measurements by surface pyranometers and a spectroradiometer aboard a high flying aircraft. The program output is also compared to ERBE measurements aboard the ERBS and NOAA-9 satellites as well as the visible bands aboard the GOES-6 and GOES-7 satellites and AVHRR bands 1 and 2 of the NOAA-9 and NOAA-1 1 satellites. The model is within 0.2 % of the radiance received by pyranometers, within 0.6 % of the ERBE radiances, and within 3 % of the radiances measured by the visible bands of the GOES and NOAA AVHRR radiometers.

  19. Direct Measure of Radiative and Dynamical Properties of an Exoplanet Atmosphere

    OpenAIRE

    de Wit, Julien; Lewis, Nikole K.; Langton, Jonathan; Laughlin, Gregory; Deming, Drake; Batygin, Konstantin; Fortney, Jonathan J.

    2016-01-01

    Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can illuminate how a planet's atmosphere responds to changes in incident flux. We report here the analysis of multi-day multi-channel photometry of the eccentric (e~ 0.93) hot Jupiter HD 80606 b obtained with the Spitzer Space Telescope. The planet's extreme eccentricity combined...

  20. Analysis of the Uncertainty in Wind Measurements from the Atmospheric Radiation Measurement Doppler Lidar during XPIA: Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Newsom, Rob [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    In March and April of 2015, the ARM Doppler lidar that was formerly operated at the Tropical Western Pacific site in Darwin, Australia (S/N 0710-08) was deployed to the Boulder Atmospheric Observatory (BAO) for the eXperimental Planetary boundary-layer Instrument Assessment (XPIA) field campaign. The goal of the XPIA field campaign was to investigate methods of using multiple Doppler lidars to obtain high-resolution three-dimensional measurements of winds and turbulence in the atmospheric boundary layer, and to characterize the uncertainties in these measurements. The ARM Doppler lidar was one of many Doppler lidar systems that participated in this study. During XPIA the 300-m tower at the BAO site was instrumented with well-calibrated sonic anemometers at six levels. These sonic anemometers provided highly accurate reference measurements against which the lidars could be compared. Thus, the deployment of the ARM Doppler lidar during XPIA offered a rare opportunity for the ARM program to characterize the uncertainties in their lidar wind measurements. Results of the lidar-tower comparison indicate that the lidar wind speed measurements are essentially unbiased (~1cm s-1), with a random error of approximately 50 cm s-1. Two methods of uncertainty estimation were tested. The first method was found to produce uncertainties that were too low. The second method produced estimates that were more accurate and better indicators of data quality. As of December 2015, the first method is being used by the ARM Doppler lidar wind value-added product (VAP). One outcome of this work will be to update this VAP to use the second method for uncertainty estimation.

  1. Instrument development for atmospheric radiation measurement (ARM): Status of the Atmospheric Emitted Radiance Interferometer - extended Resolution (AERI-X), the Solar Radiance Transmission Interferometer (SORTI), and the Absolute Solar Transmission Inferometer (ASTI)

    Energy Technology Data Exchange (ETDEWEB)

    Murcray, F.; Stephen, T.; Kosters, J. [Univ. of Denver, CO (United States)

    1996-04-01

    This paper describes three instruments currently under developemnt for the Atmospheric Radiation Measurement (ARM) Program at the University of Denver: the AERI-X (Atmospheric Emitted Radiance Interferometer-Extended Resolution) and the SORTI (Solar R adiance Transmission Interferometer), and ASTI (Absolute Solar transmission Interferometer).

  2. A 25-month database of stratus cloud properties generated from ground-based measurements at the Atmospheric Radiation Measurement Southern Great Plains Site

    International Nuclear Information System (INIS)

    A 25-month database of the macrophysical, microphysical, and radiative properties of isolated and overcast low-level stratus clouds has been generated using a newly developed parameterization and surface measurements from the Atmospheric Radiation Measurement central facility in Oklahoma. The database (5-min resolution) includes two parts: measurements and retrievals. The former consist of cloud base and top heights, layer-mean temperature, cloud liquid water path, and solar transmission ratio measured by a ground-based lidar/ceilometer and radar pair, radiosondes, a microwave radiometer, and a standard Eppley precision spectral pyranometer, respectively. The retrievals include the cloud-droplet effective radius and number concentration and broadband shortwave optical depth and cloud and top-of-atmosphere albedos. Stratus without any overlying mid or high-level clouds occurred most frequently during winter and least often during summer. Mean cloud-layer altitudes and geometric thicknesses were higher and greater, respectively, in summer than in winter. Both quantities are positively correlated with the cloud-layer mean temperature. Mean cloud-droplet effective radii range from 8.1 μm in winter to 9.7 μm during summer, while cloud-droplet number concentrations during winter are nearly twice those in summer. Since cloud liquid water paths are almost the same in both seasons, cloud optical depth is higher during the winter, leading to greater cloud albedos and lower cloud transmittances. (c) 2000 American Geophysical Union

  3. High spectral resolution fourier transform infrared instruments for the Atmospheric Radiation Measurement Program

    International Nuclear Information System (INIS)

    Major accomplishments of the Atmospheric Emitted Radiance Interferometer (AERI) Instrument Development Program (IDP) effort have been to (1) develop and extensively test a new radiometric calibration subsystem with improved accuracy and robustness; (2) interact with Bomem, Inc., leading to the development of a two-channel interferometer with the required software characteristics; (3) develop new operational control software and network interfaces; (4) develop new analysis techniques to handle the complete calibration, including a detector nonlinearity correction, wavelength scale standardization, and a finite field-of-view correction; (5) integrate the required hardware, operational control software, and analysis software into a complete system which interfaces to the CART data system and operates remotely; and (6) perform extensive field testing of the AERI system prototype

  4. The DOE Atmospheric Radiation Measurement Program's LES ARM Symbiotic Simulation and Observation (LASSO) Workflow: Initialization, Forcing and Multiscale Data Assimilation

    Science.gov (United States)

    Li, Z.; Cheng, X.; Gustafson, W. I., Jr.; Xiao, H.; Endo, S.; Vogelmann, A. M.; Toto, T.

    2015-12-01

    The Department of Energy Atmospheric Radiation Measurement (ARM) Program is developing a routine large-eddy simulation (LES) modeling framework at the ARM Climate Research Facility sites, known as the "LES ARM Symbiotic Simulation and Observation" (LASSO) Workflow. The routine simulations will be assessed using comprehensive ARM observations of the atmosphere and land-surface states, particularly cloud observations. Since small changes in thermodynamic profiles can manifest large changes in cloud properties, successful simulations require careful initialization, appropriate forcing, and possibly suitable lateral boundary conditions. We use a multiscale data assimilation (MS-DA) system as a major methodology for producing forcing datasets required by the LES modeling. The MS-DA will be implemented in the regional Weather Research and Forecasting (WRF) model at a cloud resolving resolution (~1 km). MS-DA leverages existing reanalyses (e.g., the NCEP North American Regional Reanalysis, NARR) and operational forecasting products (e.g. the North American Mesoscale Forecast System, NAM; the High-Resolution Rapid Refresh, HRRR) products, and takes advantage of ARM observations to directly constrain the spectra of horizontal scales down to a few km. The analysis from the MS-DA allows deriving initial conditions and forcing datasets for a range of spatial and temporal scales, developing hydrometeor forcing, exploring time-varying boundary conditions, and diagnosing other needed thermodynamic variables. It is stressed that the datasets from the MS-DA are integrated with datasets from other sources to form ensembles to account for uncertainties. The methodologies, implementation and evaluations are presented.

  5. Atmospheric Radiation Measurement Program Climate Research Facility Operations Quarterly Report July 1 - September 30, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Sisterson, DL

    2005-09-30

    Description. Individual raw data streams from instrumentation at the ACRF fixed and mobile sites are collected and sent to the Data Management Facility (DMF) at PNNL for processing in near real time. Raw and processed data are then sent daily to the ACRF Archive, where they are made available to users. For each instrument, we calculate the ratio of the actual number of data records received daily at the Archive to the expected number of data records. The results are tabulated by (1) individual data stream, site, and month for the current year and (2) site and fiscal year dating back to 1998. The DOE requires national user facilities to report time-based operating data. The requirements concern the actual hours of operation (ACTUAL); the estimated maximum operation or uptime goal (OPSMAX), which accounts for planned downtime; and the VARIANCE [1 – (ACTUAL/OPSMAX)], which accounts for unplanned downtime. The OPSMAX time for the third quarter for the Southern Great Plains (SGP) site is 2,097.6 hours (0.95 × 2,208 hours this quarter). The OPSMAX for the North Slope Alaska (NSA) site is 1,987.2 hours (0.90 × 2,208), and that for the Tropical Western Pacific (TWP) site is 1,876.8 hours (0.85 × 2,208). The OPSMAX time for the ARM Mobile Facility (AMF) is 2,097.6 hours (0.95 × 2,208). The differences in OPSMAX performance reflect the complexity of local logistics and the frequency of extreme weather events. It is impractical to measure OPSMAX for each instrument or data stream. Data availability reported here refers to the average of the individual, continuous data streams that have been received by the ACRF Archive. Data not at the Archive are caused by downtime (scheduled or unplanned) of the individual instruments. Therefore, data availability is directly related to individual instrument uptime. Thus, the average percent of data in the Archive represents the average percent of the time (24 hours per day, 92 days for this quarter) the instruments were operating

  6. Contributions of the Atmospheric Radiation Measurement (ARM) Program and the ARM Climate Research Facility to the U.S. Climate Change Science Program

    Energy Technology Data Exchange (ETDEWEB)

    SA Edgerton; LR Roeder

    2008-09-30

    The Earth’s surface temperature is determined by the balance between incoming solar radiation and thermal (or infrared) radiation emitted by the Earth back to space. Changes in atmospheric composition, including greenhouse gases, clouds, and aerosols can alter this balance and produce significant climate change. Global climate models (GCMs) are the primary tool for quantifying future climate change; however, there remain significant uncertainties in the GCM treatment of clouds, aerosol, and their effects on the Earth’s energy balance. The 2007 assessment (AR4) by the Intergovernmental Panel on Climate Change (IPCC) reports a substantial range among GCMs in climate sensitivity to greenhouse gas emissions. The largest contributor to this range lies in how different models handle changes in the way clouds absorb or reflect radiative energy in a changing climate (Solomon et al. 2007). In 1989, the U.S. Department of Energy (DOE) Office of Science created the Atmospheric Radiation Measurement (ARM) Program within the Office of Biological and Environmental Research (BER) to address scientific uncertainties related to global climate change, with a specific focus on the crucial role of clouds and their influence on the transfer of radiation in the atmosphere. To address this problem, BER has adopted a unique two-pronged approach: * The ARM Climate Research Facility (ACRF), a scientific user facility for obtaining long-term measurements of radiative fluxes, cloud and aerosol properties, and related atmospheric characteristics in diverse climate regimes. * The ARM Science Program, focused on the analysis of ACRF data to address climate science issues associated with clouds, aerosols, and radiation, and to improve GCMs. This report describes accomplishments of the BER ARM Program toward addressing the primary uncertainties related to climate change prediction as identified by the IPCC.

  7. Atmospheric thermal structure and cloud features in the southern hemisphere of Venus as retrieved from VIRTIS/VEX radiation measurements

    Science.gov (United States)

    Haus, R.; Kappel, D.; Arnold, G.

    2014-04-01

    Thermal structure and cloud features in the atmosphere of Venus are investigated using spectroscopic nightside measurements recorded by the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS) aboard ESA’s Venus Express mission in the moderate resolution infrared mapping channel (M-IR, 1-5 μm). New methodical approaches and retrieval results for the northern hemisphere have been recently described by Haus et al. (Haus, R., Kappel, D., Arnold, G. [2013]. Planet. Space Sci. 89, 77-101. http://dx.doi.org/10.1016/j.pss.2013.09.020). Now, southern hemisphere maps of mesospheric temperature and cloud parameter fields are presented that cover variations with altitude, latitude, local time, and mission time. Measurements from the entire usable data archive are utilized comprising radiation spectra recorded during eight Venus solar days between April 2006 and October 2008. Zonal averages of retrieved temperature altitude profiles in both hemispheres are very similar and give evidence of global N-S axial symmetry of atmospheric temperature structure. Cold collar and warmer polar vortex regions exhibit the strongest temperature variability with standard deviations up to 8.5 K at 75°S and 63 km altitude compared with about 1.0 K at low and mid latitudes above 75 km. The mesospheric temperature field strongly depends on local time. At altitudes above about 75 km, the atmosphere is warmer in the second half of night, while the dawn side at lower altitudes is usually colder than the dusk side by about 8 K. Local minimum temperature of 220 K occurs at 03:00 h local time at 65 km and 60°S. Temperature standard deviation at polar latitudes is particularly large near midnight. Temperature variability with solar longitude is forced by solar thermal tides with a dominating diurnal component. The influence of observed cloud parameter changes on retrieved mesospheric zonal average temperature structure is moderate and does not exceed 2-3 K at altitudes between 60 and 75 km

  8. Atmospheric radiative transfer simulation for atmospheric correction of remote sensing data

    Institute of Scientific and Technical Information of China (English)

    Yunfei Bao; Shengbo Chen

    2006-01-01

    The radiance leaving the earth-atmosphere system which can be sensed by a satellite borne radiometer is the sum of radiation emission from the earth surface and each atmospheric level that are transmitted to the top of the atmosphere. The radiation emission from the earth surface and the radiance of each atmospheric level can be separated from the radiance at the top the atmospheric level measured by a satellite borne radiometer. However, it is very difficult to measure the atmospheric radiance, especially the synchronous measurement with the satellite. Thus some atmospheric radiative transfer models have been developed to provide many options for modeling atmospheric radiation transport, such as LOWTRAN, MODTRAN, 6S, FASCODE, LBLRTM, SHARC, and SAMM. Meanwhile, these models can support the detailed detector system design, the optimization and evaluation of satellite mission parameters, and the data processing procedures. As an example, the newly atmospheric radiative transfer models, MODTRAN will be compared with other models after the atmospheric radiative transfer is described. And the atmospheric radiative transfer simulation procedures and their applications to atmospheric transmittance, retrieval of atmospheric elements, and surface parameters, will also be presented.

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

    International Nuclear Information System (INIS)

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

  10. Determination of radiation doses caused by release into the atmosphere by nuclear power plants, based on measurement of emission and immission

    International Nuclear Information System (INIS)

    The radiation impact of nuclear facilities, and the nuclear power plants as well, can be determined by using two methods. The first one calculates the dose of critical group of population based on the release, meteorological and hydrological parameters. The second method gives an estimate of the additional dose caused by the nuclear facility from the radiological measurements in the environment. This article compares this two methods for the release in the atmosphere, and gives an estimate of the relative error. The comparison can be applied for cases when the atmospheric pollution is released from a point type source, so for the conventional power plants as well. (author)

  11. Comparison of the atmospheric dispersion calculation with the measurement of γ-radiation levels from Ar-41 releases

    International Nuclear Information System (INIS)

    The purpose of the study was to check the accuracy of a simple gaussian atmospheric diffusion model for a complex terrain condition in Germany. In the frame of the existing surveillance system, the annual γ doses due to 41Ar emission from a research reactor have been measured in the environment, mainly with sensitive G-M detectors. The computer code AIREM was used to calculate the atmospheric dispersion. This code is based on a simple sector averaged gaussian diffusion equation for long-term average calculation. For the calculation of cloud-dose rates, the finite extent model (Computer Code EGAD) was used. The results showed that at fairly flat locations the ratios of calculated to measured doses vary between 1.8 to 3.4 Measurements were mainly made with sensitive G-M detectors. (U.K.)

  12. Migrating birds : assessment of impact on 915-MHz radar wind profiler performance at the Atmospheric Radiation Measurement Program's southern great plains

    International Nuclear Information System (INIS)

    The U. S. Department of Energy's Atmospheric Radiation Measurement Program is running a small network of 915-MHz radar wind profilers (RWPs) at its Southern Great Plains Cloud and Radiation Testbed site in northern Oklahoma and southern Kansas. Seasonal migration of passerines may cause significant interference with the operation of 915-MHz RWPs. The extent of this ''bird jamming'' depends on the radar's parameters, the place of deployment, the season, and the time of day. This poster presents a new diagnostic method for detecting possible bird contamination in RWP data, along with an evaluation of the method using a three-year data set for two RWPs

  13. Solar and thermal radiation in the Venus atmosphere

    Science.gov (United States)

    Moroz, V. I.; Ekonomov, A. P.; Moshkin, B. E.; Revercomb, H. E.; Sromovsky, L. A.; Schofield, J. T.

    1985-01-01

    Attention is given to the solar and thermal radiation fields of Venus. Direct measurements and the results of numerical models based on direct measurements are presented. Radiation outside the atmosphere is considered with emphasis placed on global energy budget parameters, spectral and angular dependences, spatial distribution, and temporal variations of solar and thermal radiation. Radiation fluxes inside the atmosphere below 90 km are also considered with attention given to the solar flux at the surface, solar and thermal radiation fluxes from 100 km to the surface, and radiative heating and cooling below 100 km.

  14. MAX-DOAS measurements of atmospheric trace gases in Ny-Ålesund - Radiative transfer studies and their application

    OpenAIRE

    Wittrock, F.; Oetjen, H.; Richter, A.; Fietkau, S.; Medeke, T.; Rozanov, A.; Burrows, J.P.

    2004-01-01

    International audience A new approach to derive tropospheric concentrations of some atmospheric trace gases from ground-based UV/vis measurements is described. The instrument, referred to as the MAX-DOAS, is based on the well-known UV/vis instruments, which use the sunlight scattered in the zenith sky as the light source and the method of Differential Optical Absorption Spectroscopy (DOAS) to derive column amounts of absorbers like ozone and nitrogen dioxide. Substantial enhancements have ...

  15. Atmospheric effects on radiation reflected from soil and vegetation as measured by orbital sensors using various scanning directions

    Science.gov (United States)

    Slater, P. N.; Jackson, R. D.

    1982-01-01

    Ground-measured spectral reflectance data for Avondale loam and drought-stressed and unstressed wheat were converted into digital counts for spectral bands 5 and 7 of the Landsat Multispectral Scanner System (MSS). For dry loam, the differences between ratios of MSS bands 7-5 as determined from space and from ground level measurements were 2.3 percent for clear and 5.6 percent for turbid atmospheric conditions. By contrast, for wet loam the differences were 10.4 and 29.5 percent. It is found that atmospheric conditions may cause a delay of from 3 to 7 days in the discrimination between drought-stressed and unstressed wheat. For oblique angle observations the atmospheric modification of ground-measured reflectances increased with angle at a greater rate in the 0/180 deg azimuth than in the 90/270 deg azimuth. Implications of this result are discussed for oblique angle Systeme Probatoire d'Observation de la Terre (SPOT), Mapsat, future multispectral linear array system imagery, and wide-angle imagery collected from scanners in high-altitude aircraft.

  16. Model Assessment of the Ability of MODIS to Measure Top-of-Atmosphere Direct Radiative Forcing from Smoke Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Remer, L. A.; Kaufman, Yoram J.; Levin, Zev; Ghan, Steven J.

    2002-02-01

    The new generation of satellite sensors such as the MODerate resolution Imaging Spectroradiometer (MODIS) will be able to detect and characterize global aerosols with an unprecedented accuracy. The question remains whether this accuracy will be sufficient to narrow the uncertainties in our estimates of aerosol radiative forcing at the top of the atmosphere. We narrow the discussion to cloud free direct forcing. Satellite remote sensing detects aerosol optical thickness with the least amount of relative error when aerosol loading is high. Satellites are less effective when aerosol loading is low. We use the monthly mean results of two global aerosol transport models to simulate the spatial distribution of smoke aerosol in the Southern Hemisphere during the tropical biomass burning season. This spatial distribution allows us to determine that 87-94% of the smoke aerosol forcing at the top of the atmosphere occurs in grid squares with sufficient signal to noise ratio to be detectable from space. The uncertainty of quantifying the smoke aerosol forcing in the Southern Hemisphere depends on the uncertainty introduced by errors in estimating the background aerosol, errors resulting from uncertainties in surface properties and errors resulting from uncertainties in assumptions of aerosol properties. These three errors combine to give overall uncertainties of 1.2 to 2.2 Wm-2 (16-60%) in determining the Southern Hemisphere smoke aerosol forcing at the top of the atmosphere. The range of values depend on which estimate of MODIS retrieval uncertainty is used, either the theoretical calculation (upper bound) or the empirical estimate (lower bound). Strategies that use the satellite data to derive flux directly or use the data in conjunction with ground-based remote sensing and aerosol transport models can reduce these uncertainties.

  17. RADIATION HYDRODYNAMICS OF HOT JUPITER ATMOSPHERES

    International Nuclear Information System (INIS)

    Radiative transfer in planetary atmospheres is usually treated in the static limit, i.e., neglecting atmospheric motions. We argue that hot Jupiter atmospheres, with possibly fast (sonic) wind speeds, may require a more strongly coupled treatment, formally in the regime of radiation hydrodynamics. To lowest order in v/c, relativistic Doppler shifts distort line profiles along optical paths with finite wind velocity gradients. This leads to flow-dependent deviations in the effective emission and absorption properties of the atmospheric medium. Evaluating the overall impact of these distortions on the radiative structure of a dynamic atmosphere is non-trivial. We present transmissivity and systematic equivalent width excess calculations which suggest possibly important consequences for radiation transport in hot Jupiter atmospheres. If winds are fast and bulk Doppler shifts are indeed important for the global radiative balance, accurate modeling and reliable data interpretation for hot Jupiter atmospheres may prove challenging: it would involve anisotropic and dynamic radiative transfer in a coupled radiation-hydrodynamical flow. On the bright side, it would also imply that the emergent properties of hot Jupiter atmospheres are more direct tracers of their atmospheric flows than is the case for solar system planets. Radiation hydrodynamics may also influence radiative transfer in other classes of hot exoplanetary atmospheres with fast winds.

  18. Measurement of the Atmospheric $\

    CERN Document Server

    Aartsen, M G; Abdou, Y; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beattie, K; Beatty, J J; Bechet, S; Tjus, J Becker; Becker, K -H; Bell, M; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohaichuk, S; Bohm, C; Bose1, D; Boser, S; Botner, O; Brayeur, L; Brown, A M; Bruijn, R; Brunner, J; Buitink, S; Carson, M; Casey, J; Casier, M; Chirkin, D; Christy, B; Clark, K; Clevermann, F; Cohen, S; Cowen, D F; Silva, A H Cruz; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; De Ridder, S; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Diaz-Velez, J C; Dreyer, J; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Eisch, J; Ellsworth, R W; Engdegard, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Franckowiak, A; Franke, R; Frantzen, K; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glusenkamp, T; Goldschmidt, A; Golup, G; Goodman, J A; Gora, D; Grant, D; Gross, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hanson, K; Heereman, D; Heimann, P; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Jlelati, O; Kappes, A; Karg, T; Karle, A; Kiryluk, J; Kislat, F; Klas, J; Klein, S R; Kohne, J -H; Kohnen, G; Kolanoski, H; Kopke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Landsman, H; Larson, M J; Lauer, R; Lesiak-Bzdak, M; Lunemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; McNally, F; Meagher, K; Merck, M; Meszaros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Nowicki, S C; Nygren, D R; Obertacke, A; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Pepper, J A; Heros, C Perez de los; Pieloth, D; Pirk, N; Posselt, J; Price, P B; Przybylski, G T; Radel, L; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Salameh, T; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Scheel, M; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schoneberg, S; Schonherr, L; Schonwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Seo, S H; Sestayo, Y; Seunarine, S; Sheremata, C; Smith, M W E; Soiron, M; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stasik, A; Stezelberger, T; Stokstad, R G; Stoss, A; Strahler, E A; Strom, R; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Usner, M; van der Drift, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge1, M; Vraeghe, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wasserman, R; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zierke, S; Zilles, A; Zoll, M

    2012-01-01

    We report the first observation in a high energy neutrino telescope of cascades induced by atmospheric electron neutrinos and by neutral current interactions of atmospheric neutrinos of all flavors. Using data recorded during the first year of operation of IceCube's DeepCore low energy extension, a sample of 1029 events is observed in 281 days of data. The number of observed cascades is $N_{\\rm cascade} = 496 \\pm 66 (stat.) \\pm 88(syst.)$ and the rest of the sample consists of residual backgrounds due to atmospheric muons and charged current interactions of atmospheric muon neutrinos. The flux of the atmospheric electron neutrinos is determined in the energy range between approximately 80 GeV and 6 TeV and is consistent with models of atmospheric neutrinos.

  19. Cloud droplet size and liquid water path retrievals from zenith radiance measurements: examples from the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network

    Directory of Open Access Journals (Sweden)

    J. C. Chiu

    2012-11-01

    Full Text Available The ground-based Atmospheric Radiation Measurement Program (ARM and NASA Aerosol Robotic Network (AERONET routinely monitor clouds using zenith radiances at visible and near-infrared wavelengths. Using the transmittance calculated from such measurements, we have developed a new retrieval method for cloud effective droplet size and conducted extensive tests for non-precipitating liquid water clouds. The underlying principle is to combine a liquid-water-absorbing wavelength (i.e., 1640 nm with a non-water-absorbing wavelength for acquiring information on cloud droplet size and optical depth. For simulated stratocumulus clouds with liquid water path less than 300 g m−2 and horizontal resolution of 201 m, the retrieval method underestimates the mean effective radius by 0.8 μm, with a root-mean-squared error of 1.7 μm and a relative deviation of 13%. For actual observations with a liquid water path less than 450 g m−2 at the ARM Oklahoma site during 2007–2008, our 1.5-min-averaged retrievals are generally larger by around 1 μm than those from combined ground-based cloud radar and microwave radiometer at a 5-min temporal resolution. We also compared our retrievals to those from combined shortwave flux and microwave observations for relatively homogeneous clouds, showing that the bias between these two retrieval sets is negligible, but the error of 2.6 μm and the relative deviation of 22% are larger than those found in our simulation case. Finally, the transmittance-based cloud effective droplet radii agree to better than 11% with satellite observations and have a negative bias of 1 μm. Overall, the retrieval method provides reasonable cloud effective radius estimates, which can enhance the cloud products of both ARM and AERONET.

  20. Cloud droplet size and liquid water path retrievals from zenith radiance measurements: examples from the Atmospheric Radiation Measurement Program and the Aerosol Robotic Network

    Directory of Open Access Journals (Sweden)

    J. C. Chiu

    2012-08-01

    Full Text Available The ground-based Atmospheric Radiation Measurement Program (ARM and NASA Aerosol Robotic Network (AERONET routinely monitor clouds using zenith radiances at visible and near-infrared wavelengths. Using the transmittance calculated from such measurements, we have developed a new retrieval method for cloud effective droplet size and conducted extensive tests for non-precipitating liquid water clouds. The underlying principle is to combine a water-absorbing wavelength (i.e. 1640 nm with a non-water-absorbing wavelength for acquiring information on cloud droplet size and optical depth. For simulated stratocumulus clouds with liquid water path less than 300 g m−2 and horizontal resolution of 201 m, the retrieval method underestimates the mean effective radius by 0.8 μm, with a root-mean-squared error of 1.7 μm and a relative deviation of 13%. For actual observations with a liquid water path less than 450 g m−2 at the ARM Oklahoma site during 2007–2008, our 1.5 min-averaged retrievals are generally larger by around 1 μm than those from combined ground-based cloud radar and microwave radiometer at a 5 min temporal resolution. We also compared our retrievals to those from combined shortwave flux and microwave observations for relatively homogeneous clouds, showing that the bias between these two retrieval sets is negligible, but the error of 2.6 μm and the relative deviation of 22% are larger than those found in our simulation case. Finally, the transmittance-based cloud effective droplet radii agree to better than 11% with satellite observations and have a negative bias of 1 μm. Overall, the retrieval method provides reasonable cloud effective radius estimates, which can enhance the cloud products of both ARM and AERONET.

  1. LINTRAN v2.0: A linearised vector radiative transfer model for efficient simulation of satellite-born nadir-viewing reflection measurements of cloudy atmospheres

    International Nuclear Information System (INIS)

    Radiance measurements of solar radiation that is backscattered by the Earth's atmosphere or surface contain information about the atmospheric composition and the state of the Earth's surface. Retrieving such information from satellite-based observations in nadir geometry employs a radiative transfer forward model. The forward model simulates the observed quantity, aiming to reproduce the observation. LINTRAN v2.0 is a linearised vector radiative transfer forward model, employing forward-adjoint theory, that is capable of modelling cloud contaminated satellite observations and their derivatives with respect to the state of the atmosphere and the Earth's surface in a numerically efficient manner. A significant gain in efficiency with respect to its predecessor (LINTRAN v1.0) is achieved through a mathematical framework that combines an approximate iterative solving method using the forward-adjoint perturbation theory with separation of the first N orders of scattering from the diffuse intensity vector field. Contributions to the observable up to order of scattering N are recursively solved in an analytical manner. Contributions from higher orders of scattering are subsequently solved in a numerical manner, assuming that the intensity field varies linearly with the vertical coordinate within an optically homogeneous model layer. This method is implemented in LINTRAN v2.0, choosing N=2, within the general framework of forward-adjoint perturbation theory. This new approach allows us to decrease the number of model layers and the degree of angular quadrature within the numerical solver by a factor of 10 and 1.4 respectively, compared to the previous model version, assuming a homogeneous atmosphere loaded with scattering Mie particles (size parameter χ≈35). In this homogeneous atmosphere, the reduced discretisation sampling in turn reduces the numerical effort associated with the numerical matrix solver by a factor of 42 relative to the previous model

  2. Radiative equilibrium and escape of Pluto's atmosphere

    Science.gov (United States)

    Erwin, Justin; Koskinen, Tommi T.; Yelle, Roger V.

    2015-11-01

    Observations of Pluto’s extend atmosphere by the New Horizons spacecraft motivate an update to our modeling effort on Pluto’s atmosphere. New Horizons observations have already improved our constraints on planet radius and surface pressure, which are key to modeling the atmospheric structure. We model the radiative conductive equilibrium in the lower atmosphere combined with the UV driven escape model of the upper atmosphere. The non-LTE radiative transfer model in the lower atmosphere include heating and cooling by CH4, CO, and HCN. The escape model of the upper atmosphere is updated to include diffusion and escape of each molecular component. These results will be used to aid in the analysis and better understanding of the full atmospheric structure.

  3. Remote measurement of atmospheric pollutants

    Science.gov (United States)

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

    1979-01-01

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

  4. Radiation flux measuring device

    International Nuclear Information System (INIS)

    A radiation flux measuring device is described which employs an attenuator circuit, the output of which is maintained constant, connected to a radiation detector. Means connected to the attenuator circuit produce an output representing the log of the a-c component of the radiation detector, thereby providing a true root mean square logarithmic output

  5. Radiation flux measuring device

    International Nuclear Information System (INIS)

    A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

  6. Radiative transfer in the cloudy atmosphere

    OpenAIRE

    Mayer B.

    2009-01-01

    Radiative transfer in clouds is a challenging task, due to their high spatial and temporal variability which is unrivaled by any other atmospheric species. Clouds are among the main modulators of radiation along its path through the Earth’s atmosphere. The cloud feedback is the largest source of uncertainty in current climate model predictions. Cloud observation from satellites, on a global scale, with appropriate temporal and spatial sampling is therefore one of the top aims of current Earth...

  7. The Radiation Environment of Exoplanet Atmospheres

    Directory of Open Access Journals (Sweden)

    Jeffrey L. Linsky

    2014-10-01

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

  8. Measurement of ion density in an atmospheric pressure argon with pin-to-plate dielectric barrier discharge by resonance of plasma radiation

    International Nuclear Information System (INIS)

    The measurements of the ion densities in the atmospheric AC barrier corona argon discharge are carried out by receiving and analyzing the frequencies of the electromagnetic radiation emitted from the plasma. An auxiliary excitation source composed of a pin-to-pin discharge system is introduced to excite the oscillations of the main discharge. To analyze the resonance mechanism, a complemented model based on a one-dimensional description of forced vibrations is given. Calculations indicate that Ar2+ is the dominant ion (∼89% in number density). By analyzing resonance frequencies, the ion densities of Ar2+ are in the order of 1019∼1020m−3 and increase slowly as the applied voltage increases

  9. Radiation environment models and the atmospheric cutoff

    Science.gov (United States)

    Konradi, Andrei; Hardy, Alva C.; Atwell, William

    1987-01-01

    The limitations of radiation environment models are examined by applying the model to the South Atlantic anomaly (SAA). The local magnetic-field-intensity (in gauss) and McIlwain (1961) drift-shell-parameter contours in the SAA are analyzed. It is noted that it is necessary to decouple the atmospheric absorption effects from the trapped radiation models in order to obtain accurate radiation dose predictions. Two methods for obtaining more accurate results are proposed.

  10. Space, Atmospheric, and Terrestrial Radiation Environments

    Science.gov (United States)

    Barth, Janet L.; Dyer, C. S.; Stassinopoulos, E. G.

    2003-01-01

    The progress on developing models of the radiation environment since the 1960s is reviewed with emphasis on models that can be applied to predicting the performance of microelectronics used in spacecraft and instruments. Space, atmospheric, and ground environments are included. It is shown that models must be adapted continually to account for increased understanding of the dynamics of the radiation environment and the changes in microelectronics technology. The IEEE Nuclear and Space Radiation Effects Conference is a vital forum to report model progress to the radiation effects research community.

  11. Observation of a north-south anisotropy of atmospheric radiation at balloon altitudes

    Science.gov (United States)

    Fishman, G. J.; Watts, J. W., Jr.; Meegan, C. A.

    1976-01-01

    Measurements have been made of an azimuthal asymmetry of atmospheric radiation at balloon altitudes and mid-latitudes. The measured asymmetry is 6% peak to peak in the north-south direction at energies above 500 keV. A lack of east-west asymmetry indicates that the arrival direction of the atmospheric radiation is highly decoupled from that of the primary radiation. Present models of secondary atmospheric radiation production and transport do not quantitatively agree with the observations.

  12. Observation of a north--south anisotropy of atmospheric radiation at balloon altitudes

    International Nuclear Information System (INIS)

    Measurements have been made of an azimuthal asymmetry of atmospheric radiation at balloon altitudes and mid-latitudes. The measured asymmetry is 6% peak to peak in the north--south direction at energies above 500 keV. A lack of east--west asymmetry indicates that the arrival direction of the atmospheric radiation is highly decoupled from that of the primary radiation. Present models of secondary atmospheric radiation production and transport do not quantitatively agree with the observations

  13. Mobile Instruments Measure Atmospheric Pollutants

    Science.gov (United States)

    2009-01-01

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

  14. Multiple equilibria in radiative-convective atmospheres

    OpenAIRE

    Rennó, Nilton O.

    2011-01-01

    A one-dimensional, radiative-convective model is used to study the equilibria conditions of moist atmospheres. We show that when the hydrologic cycle is included in the model a subcritical bifurcation occurs, leading to 2 linearly stable solutions to the radiative-convective equilibria. In this case, when the net forcing is larger than a critical value, two equilibria are possible. Furthermore, a finite amplitude instability can lead to a runaway greenhouse regime when the solar forcing is la...

  15. Long and short-term atmospheric radiation analyses based on coupled measurements at high altitude remote stations and extensive air shower modeling

    Science.gov (United States)

    Hubert, G.; Federico, C. A.; Pazianotto, M. T.; Gonzales, O. L.

    2016-02-01

    In this paper are described the ACROPOL and OPD high-altitude stations devoted to characterize the atmospheric radiation fields. The ACROPOL platform, located at the summit of the Pic du Midi in the French Pyrenees at 2885 m above sea level, exploits since May 2011 some scientific equipment, including a BSS neutron spectrometer, detectors based on semiconductor and scintillators. In the framework of a IEAv and ONERA collaboration, a second neutron spectrometer was simultaneously exploited since February 2015 at the summit of the Pico dos Dias in Brazil at 1864 m above the sea level. The both high station platforms allow for investigating the long period dynamics to analyze the spectral variation of cosmic-ray- induced neutron and effects of local and seasonal changes, but also the short term dynamics during solar flare events. This paper presents long and short-term analyses, including measurement and modeling investigations considering the both high altitude stations data. The modeling approach, based on ATMORAD computational platform, was used to link the both station measurements.

  16. Impacts of the triggering function of cumulus parameterization on warm-season diurnal rainfall cycles at the Atmospheric Radiation Measurement Southern Great Plains site

    Science.gov (United States)

    Wang, Yi-Chi; Pan, Hua-Lu; Hsu, Huang-Hsiung

    2015-10-01

    In this study, we investigated the impacts of the triggering function of the deep convection scheme on diurnal rainfall variation in the middle latitudes by using the single-column version of the Community Atmospheric Model (SCAM). Using the climate statistics of a long-term ensemble analysis of SCAM simulations, we quantified and validated the diurnal rainfall climatological regimes at the Atmospheric Radiation Measurement Southern Great Plains (SGP) site. The results showed that the averaged diurnal rainfall cycle simulated using the default Zhang-Mcfarlane (ZM) scheme of the SCAM peaks near noon, which is far earlier than the observed nighttime peak phase. This bias was due to the ZM scheme, which produced spurious daytime rainfall, even during days in which only light rainfall was observed. By contrast, using a weather-focused scheme, the Simplified Arakawa-Schubert (SAS) scheme, we successfully simulated the nocturnal peak of the diurnal cycle. Experiments conducted on the ZM and SAS schemes featuring different triggering functions revealed that the relaxation of launching parcels above the planetary boundary layer (PBL) and the inclusion of convective inhibition (CIN) were crucial designs for the model to capture the nocturnal rainfall events of the SGP. The inclusion of CIN reduces spurious weak convective events, and the allowance of launching parcels being above the PBL better captures convective cloud base. The results of this study highlight the modulatory effect of low-level inhomogeneity on the diurnal variation of convection over midlatitudes and the importance of the triggering function of the deep convection scheme in capturing those variations.

  17. Instrumentation for atmospheric ion measurements

    CERN Document Server

    Aplin, K L

    2005-01-01

    Small ions are part of the atmospheric aerosol spectrum, and study of ion-aerosol interactions is fundamental in atmospheric physics. Air ion physics and instrumentation are reviewed, including the historical context. A miniaturised Gerdien condenser for ion measurement, operating in situ to minimise inlet errors, is described. Two operating modes using independent current and voltage decay measurements are employed. A more sophisticated self-calibrating and fully programmable ion mobility spectrometer (PIMS) based on the same principles, is also discussed. Detailed analysis of error terms and application of new technology is demonstrated to greatly improve its capability. Self-consistent experimental approaches, including ionisation and ion concentration instruments, are used for calibration. In developing and characterising the individual components of the PIMS, favourable and unfavourable operating regimes are identified: this approach can also be applied to other aspiration ion counting techniques. Use of...

  18. Monitoring of contamination of atmospheric environment by radiation

    International Nuclear Information System (INIS)

    Atmospheric pollution has become a worldwide problem regardless of developed industrial nations and developing countries. In particular, the pollution due to automobile exhaust gas, the carcinogenic particles in diesel exhaust and their relation to various respiratory diseases are the problems. Nitrogen oxides and sulfur oxides in exhaust gas become the cause of acid rain. Radiation began to be utilized for the measurement of the concentration of floating particles and the amount of fallout dust, the forecast of the generation and diffusion of pollutants, the elucidation of the contribution of generation sources in wide areas and so on. In this report, the circumstances that radiation became to be utilized for monitoring atmospheric environment and the present status and the perspective of the radiation utilization in the field of the preservation of atmospheric environment are described. The progress of the method of measuring floating particles in Japan is explained. The automatic measurement of floating particles by β-ray absorption method and the application of β-ray absorption method to the measurement of the amount of fallout dust, generation source particles and the exposure to floating particles of individuals for health control are described. The utilization of radiation for real time monitoring, the investigation of the generation of blown-up dust, atmospheric diffusion experiment and the elucidation of the contribution of generation sources by PIXE radioactivation analysis are reported. (K.I.)

  19. Flame Radiation Measurements

    Science.gov (United States)

    Claus, R. W.; Humenik, F. M.; Neely, G. M.

    1983-01-01

    Spectral and total flame radiation measurements exhibited: (1) that radiant heat flux increases with vision combustor inlet air pressure; (2) the effect of fuel atomization characteristics on radiant heat flux; and (3) that a reduction in fuel hydrogen content produces a significant increase in radiant heat flux primarily at low combustor pressures.

  20. Measurement of gravitational radiation

    International Nuclear Information System (INIS)

    The present article first describes some possible principles and mechanisms for detecting the gravitational radiation, and then outlines measuring techniques required for its detection. Some major issues concerned, present status of research and future prospects are also discussed. There are two possible detectors. One is the resonance type detector, which uses an elastic body with a considerable mass as antenna to catch the gravitational radiation. Gravitational radiation entering the elastic body causes an internal stress, resulting in vibration. Thus, a resonance type detector consists of an elastic body acting as antenna to catch gravitational radiation, and a transducer that converts the mechanical vibration of the antenna into electrical signals. The antenna and transducer should be contained in a vacuum highly protected from external acoustic and electromagnetic noise as well as external vibrations. Another possible detector uses a laser interferometer to detect a change in the distance between two bodies caused by gravitational radiation. Some techniques that could provide a tool for measuring such extremely small vibrations are also described and discussed. (N.K.)

  1. Analytical investigation of the atmospheric radiation limits in semigray atmospheres in radiative equilibrium

    OpenAIRE

    Pujol i Sagaró, Toni; North, Gerald R.

    2003-01-01

    We model the wavelength-dependent absorption of atmospheric gases by assuming constant mass absorption coefficients in finite-width spectral bands. Such a semigray atmosphere is analytically solved by a discrete ordinate method. The general solution is analyzed for a water vapor saturated atmosphere that also contains a carbon dioxide-like absorbing gas in the infrared. A multiple stable equilibrium with a relative upper limit in the outgoing long-wave radiation is found. Differing from previ...

  2. Electrochemical Measurement of Atmospheric Corrosion

    Science.gov (United States)

    DeArmond, Anna H.; Davis, Dennis D.; Beeson, Harold D.

    1999-01-01

    Corrosion of Shuttle thruster components in atmospheres containing high concentrations of nitrogen tetroxide (NTO) and water is an important issue in ground operations of bipropellant systems in humid locations. Measurements of the corrosivities of NTO-containing atmospheres and the responses of different materials to these atmospheres have been accomplished using an electrochemical sensor. The sensor is composed of alternating aluminum/titanium strips separated by thin insulating layers. Under high humidity conditions a thin film of water covers the surface of the sensor. Added NTO vapor reacts with the water film to form a conductive medium and establishes a galvanic cell. The current from this cell can be integrated with respect to time and related to the corrosion activity. The surface layer formed from humid air/NTO reacts in the same way as an aqueous solution of nitric acid. Nitric acid is generally considered an important agent in NTO corrosion situations. The aluminum/titanium sensor is unresponsive to dry air, responds slightly to humid air (> 75% RH), and responds strongly to the combination of humid air and NTO. The sensor response is a power function (n = 2) of the NTO concentration. The sensor does not respond to NTO in dry air. The response of other materials in this type of sensor is related to position of the material in a galvanic series in aqueous nitric acid. The concept and operation of this electrochemical corrosion measurement is being applied to other corrosive atmospheric contaminants such as hydrogen chloride, hydrogen fluoride, sulfur dioxide, and acidic aerosols.

  3. Measurement of gamma radiation around base station

    International Nuclear Information System (INIS)

    The ? -radiation have been measured around base station in Isparta region of Turkey to see the contribution of base station on the background radiation. Isparta which is surrounded by high mountain of Davras is located at southern part of Turkey. There are several volcanic activity in this region. The background radiation arises from two main sources. These are natural and technological sources. The natural radiation are mainly contributed by cosmic rays and terrestrial radiation. Cosmic rays comes from outside of the atmosphere after supernova explosion in the universe. The radiation comes direct from outside of atmosphere called primer cosmic rays and some of them can create seconder particle such as neutron.proton etc after some reaction with the oxygen, nitrogen etc in the atmosphere. The origin of terrestrial radiation are some radionucleus in rocks and soils. These are mainly 40K, 238U, 232Th and their products. The terrestrial radiation depends on geological structure of the region. The other types of γ-radiation is technological origin. With the development of technology in many different fields radiation can be produced. Nowadays mobile phones are widely used technological device and this requires base station to be established around habitable area. The electromagnetic radiations from base station and its effect are always a big question in people's mind and this would be investigated. The measurement have been performed using ASP/2e counter connected to a sing NaI(Tl) γ-ray detector. It was done around five different base station and also different altitude in Davraz mountain. The radiation dose from ambient air over five months ranges from 50 to 140 nGy h-1. The contribution of base station to the natural background radiation was clearly seen in the measurement

  4. Total tritium measurement in atmosphere

    International Nuclear Information System (INIS)

    Measurement of tritium in the atmosphere is of strong interest wherever this radionuclide is used. Therefore, a method is proposed for the joint measurement of burnable tritium, independently from its physico-chemical form, and of tritiated water. The method consists of transforming the tritiated molecules of the gases present in the air volume into tritiated water by burning them together with a known quantity of hydrogen. The water vapor is condensed and added to a liquid scintillator. The scintillator is also able to dissolve conventional filters so that the tritium attached to particulate and concentrated on these filters can be jointly measured, as will be discussed in a future report. The overall detection limit of the method is approximately 64 Bq m-3 for a combustion period of 10 min (which corresponds to sampling an air volume of 15 L) and a counting period of 10 min. This limit, much lower than the derived air concentrations in the most unfavorable cases, allows the application of the method for safety purposes. Moreover, the method can be integrated into a general procedure for the measurement of tritium in different chemical forms, to be applied in case of necessity

  5. The atmospheric implications of radiation belt remediation

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2006-08-01

    Full Text Available High altitude nuclear explosions (HANEs and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1 MeV trapped electron fluxes can shorten the operational lifetime of low Earth orbiting satellites, threatening a large, valuable population. Therefore, studies are being undertaken to bring about practical human control of the radiation belts, termed "Radiation Belt Remediation" (RBR. Here we consider the upper atmospheric consequences of an RBR system operating over either 1 or 10 days. The RBR-forced neutral chemistry changes, leading to NOx enhancements and Ox depletions, are significant during the timescale of the precipitation but are generally not long-lasting. The magnitudes, time-scales, and altitudes of these changes are no more significant than those observed during large solar proton events. In contrast, RBR-operation will lead to unusually intense HF blackouts for about the first half of the operation time, producing large scale disruptions to radio communication and navigation systems. While the neutral atmosphere changes are not particularly important, HF disruptions could be an important area for policy makers to consider, particularly for the remediation of natural injections.

  6. The radiation in the atmosphere during major solar particle events

    Science.gov (United States)

    Clucas, Simon N.; Dyer, Clive S.; Lei, Fan

    Major solar particle events can give rise to greatly enhanced radiation throughout the entire atmosphere including at aircraft altitudes. These particle events are very hard to predict and their effect on aircraft is difficult to calculate. A comprehensive model of the energetic radiation in the atmosphere has been developed based on a response matrix of the atmosphere to energetic particle incidence. This model has previously been used to determine the spectral form of several ground level neutron events including February 1956 and September/October 1989. Significant validation of the model has been possible using CREAM data flying onboard Concorde during the September/October 1989 events. Further work has been carried out for the current solar maximum, including estimates of the solar particle spectra during the July 2000, April 2001, and October 2003 events and comparisons of predicted atmospheric measurements with limited flight data. Further CREAM data have been obtained onboard commercial airlines and high altitude business jets during quiet time periods. In addition, the atmospheric radiation model, along with solar particle spectra, have been used to calculate the neutron flux and dose rates along several commercial aircraft flight paths including London to Los Angeles. The influence of rigidity cut-off suppression by geomagnetic storms is examined and shows that the received flight dose during disturbed periods can be significantly enhanced compared with quiet periods.

  7. Remote Sensing and In-Situ Observations of Arctic Mixed-Phase and Cirrus Clouds Acquired During Mixed-Phase Arctic Cloud Experiment: Atmospheric Radiation Measurement Uninhabited Aerospace Vehicle Participation

    International Nuclear Information System (INIS)

    The Atmospheric Radiation Monitor (ARM) uninhabited aerospace vehicle (UAV) program aims to develop measurement techniques and instruments suitable for a new class of high altitude, long endurance UAVs while supporting the climate community with valuable data sets. Using the Scaled Composites Proteus aircraft, ARM UAV participated in Mixed-Phase Arctic Cloud Experiment (M-PACE), obtaining unique data to help understand the interaction of clouds with solar and infrared radiation. Many measurements obtained using the Proteus were coincident with in-situ observations made by the UND Citation. Data from M-PACE are needed to understand interactions between clouds, the atmosphere and ocean in the Arctic, critical interactions given large-scale models suggest enhanced warming compared to lower latitudes is occurring

  8. Atmospheric Measurements of Neutral Nucleating Clusters (Invited)

    Science.gov (United States)

    Zhao, J.; Eisele, F. L.; Smith, J. N.; Chen, M.; Jiang, J.; Kuang, C.; McMurry, P. H.

    2010-12-01

    Nanoparticles produced by nucleation can subsequently grow to cloud condensation nuclei (CCN) within one or two days and hence affect cloud formation, precipitation, and atmospheric radiation budgets. As an intermediate stage between molecules and nanoparticles, neutral molecular clusters are believed to play an important role in processes that lead to boundary layer nucleation. Therefore, knowledge of chemical composition, concentrations, thermodynamic properties, and evolution of neutral molecular clusters is essential to better elucidate the nucleation mechanism and to reduce the uncertainty in nucleation rates used in global climate models. Here we present laboratory and field measurements from a recently developed chemical ionization mass spectrometer (the Cluster-CIMS) designed to measure atmospheric neutral clusters (Zhao et al., 2010). The sensitivity of the Cluster-CIMS was significantly improved by using a unique conical octopole device in the first vacuum stage for transmitting and focusing ions, which was further confirmed by ion trajectory simulations using SIMION. The ion cluster formation in the atmospheric-pressure inlet was controlled by two processes: neutral ionization and ion-induced clustering (IIC), which can be differentiated from the time independency of the intensity ratio between the cluster and monomer ions. Two methods were employed to separate neutral clusters from the ion-induced clustering. The concentrations and distribution of the neutral nucleating clusters containing up to 4 H2SO4 are estimated from the above methods at three measurement sites in the US (NCAR foothill laboratory, Manitou Forest Observatory, and Atlanta). Typically, the molecular cluster concentrations are well correlated with the concentrations of nanoparticles measured simultaneously during the nucleation event periods. The Cluster-CIMS was employed to measure clusters containing both sulfuric acid and amines in summer 2010 at NCAR foothill laboratory

  9. Radar range measurements in the atmosphere.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2013-02-01

    The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  10. Measurement and detection of radiation

    CERN Document Server

    Tsoulfanidis, Nicholas

    2015-01-01

    This fourth edition reflects recent major developments that have occurred in radiation detector materials, systems, and applications. It continues to provide the most practical and up-to-date introduction to radiation detector technology, proper measurement techniques, and analysis of results for engineers and scientists using radiation sources. New chapters emphasize the expanded use of radiation detection systems in nuclear non-proliferation, homeland security, and nuclear medicine. The book also discusses the correct ways to perform measurements following current health physics procedures.

  11. Radiation protection, measurements and methods

    International Nuclear Information System (INIS)

    The introductory lectures discuss subjects such as radiation protection principles and appropriate measuring techniques; methods, quantities and units in radiation protection measurement; technical equipment; national and international radiation protection standards. The papers presented at the various sessions deal with: Dosimetry of external radiation (27 papers); Working environment monitoring and emission monitoring (21 contributions); Environmental monitoring (19 papers); Incorporation monitoring (9 papers); Detection limits (4 papers); Non-ionizing radiation, measurement of body dose and biological dosimetry (10 papers). All 94 contributions (lectures, compacts and posters) are retrievable as separate records. (HP)

  12. Radiative transfer through terrestrial atmosphere and ocean: Software package SCIATRAN

    International Nuclear Information System (INIS)

    tool for a wide range of remote sensing applications. Here, we present some selected comparisons of SCIATRAN simulations to published benchmark results, independent radiative transfer models, and various measurements from satellite, ground-based, and ship instruments. Methods for solving inverse problems related to remote sensing of the Earth's atmosphere using the SCIATRAN software are outside the scope of this study and will be discussed in a follow-up paper. The SCIATRAN software package along with a detailed User's Guide is freely available for non-commercial use via the webpage of the Institute of Environmental Physics (IUP), University of Bremen: (http://www.iup.physik.uni-bremen.de/sciatran). -- Highlights: • The description of the numerical aspects of the vectorial radiative transfer equation solution. • The application of the software for the simulation of radiative transfer in ocean. • The description of bidirectional distribution reflectance function models. • The full description of aerosol, cloud, and trace gases databases used in the framework of SCIATRAN. • The detailed description of applications of SCIATRAN for atmospheric optics

  13. MSL-RAD radiation environment measurements.

    Science.gov (United States)

    Guo, Jingnan; Zeitlin, Cary; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Ehresmann, Bent; Köhler, Jan; Böhm, Eckart; Böttcher, Stephan; Brinza, David; Burmeister, Sönke; Cucinotta, Francis; Martin, Cesar; Posner, Arik; Rafkin, Scot; Reitz, Guenther

    2015-09-01

    In this study, results are presented from the on-board radiation assessment detector (RAD) of Mars Science Laboratory (MSL). RAD is designed to measure the energetic particle radiation environment, which consists of galactic cosmic rays (GCRs) and solar energetic particles (SEPs) as well as secondary particles created by nuclear interactions of primary particles in the shielding (during cruise) or Martian soil and atmosphere (surface measurements). During the cruise, RAD collected data on space radiation from inside the craft, thus allowing for a reasonable estimation of what a human crew travelling to/from Mars might be exposed to. On the surface of Mars, RAD is shielded by the atmosphere (from above) and the planet itself (from below). RAD measures the first detailed radiation data from the surface of another planet, and they are highly relevant for planning future crewed missions. The results for radiation dose and dose equivalent (a quantity most directly related to human health risk) are presented during the cruise phase, as well as on the Martian surface. Dose and dose equivalent are dominated by the continuous GCR radiation, but several SEP events were also detected and are discussed here. PMID:25969529

  14. Atmospheric trace gas measurements in the tropics

    OpenAIRE

    Petersen, Anna Katinka

    2009-01-01

    Fourier Transform Infrared (FTIR) spectrometry has been used for ground-based solar absorption, laboratory and flux measurements, to study the atmospheric composition, as well as physical and chemical processes in the atmosphere.The solar absorption FTIR measurements have been performed in Paramaribo, Suriname (5.8 N, 55.2 W) between September 2004 and November 2007 and represent the first remote sensing measurements in the inner tropics over severalyears. These measurements are of great impo...

  15. Radiative transfer in atmosphere-sea ice-ocean system

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z.; Stamnes, K.; Weeks, W.F. [Univ. of Alaska, Fairbanks, AK (United States); Tsay, S.C. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    1996-04-01

    Radiative energy is critical in controlling the heat and mass balance of sea ice, which significantly affects the polar climate. In the polar oceans, light transmission through the atmosphere and sea ice is essential to the growth of plankton and algae and, consequently, to the microbial community both in the ice and in the ocean. Therefore, the study of radiative transfer in the polar atmosphere, sea ice, and ocean system is of particular importance. Lacking a properly coupled radiative transfer model for the atmosphere-sea ice-ocean system, a consistent study of the radiative transfer in the polar atmosphere, snow, sea ice, and ocean system has not been undertaken before. The radiative transfer processes in the atmosphere and in the ice and ocean have been treated separately. Because the radiation processes in the atmosphere, sea ice, and ocean depend on each other, this separate treatment is inconsistent. To study the radiative interaction between the atmosphere, clouds, snow, sea ice, and ocean, a radiative transfer model with consistent treatment of radiation in the coupled system is needed and is under development.

  16. Radiation detector device for measuring ionizing radiation

    International Nuclear Information System (INIS)

    The device contains a compensating filter circuit, which guarantees measurement of the radiation dose independent of the energy or independent of the energy and direction. The compensating filter circuit contains a carrier tube of a slightly absorbing metal with an order number not higher than 35, which surrounds a tubular detector and which carries several annular filter parts on its surface. (orig./HP)

  17. Atmospheric transmittance model for photosynthetically active radiation

    Energy Technology Data Exchange (ETDEWEB)

    Paulescu, Marius; Stefu, Nicoleta; Gravila, Paul; Paulescu, Eugenia; Boata, Remus; Pacurar, Angel; Mares, Oana [Physics Department, West University of Timisoara, V Parvan 4, 300223 Timisoara (Romania); Pop, Nicolina [Department of Physical Foundations of Engineering, Politehnica University of Timisoara, V Parvan 2, 300223 Timisoara (Romania); Calinoiu, Delia [Mechanical Engineering Faculty, Politehnica University of Timisoara, Mihai Viteazu 1, 300222 Timisoara (Romania)

    2013-11-13

    A parametric model of the atmospheric transmittance in the PAR band is presented. The model can be straightforwardly applied for calculating the beam, diffuse and global components of the PAR solar irradiance. The required inputs are: air pressure, ozone, water vapor and nitrogen dioxide column content, Ångström's turbidity coefficient and single scattering albedo. Comparison with other models and ground measured data shows a reasonable level of accuracy for this model, making it suitable for practical applications. From the computational point of view the calculus is condensed into simple algebra which is a noticeable advantage. For users interested in speed-intensive computation of the effective PAR solar irradiance, a PC program based on the parametric equations along with a user guide are available online at http://solar.physics.uvt.ro/srms.

  18. An Analytic Radiative-Convective Model for Planetary Atmospheres

    CERN Document Server

    Robinson, Tyler D; 10.1088/0004-637X/757/1/104

    2012-01-01

    We present an analytic 1-D radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to be in hydrostatic equilibrium, with a power law scaling between the atmospheric pressure and the gray thermal optical depth. The convective portions of our models are taken to follow adiabats that account for condensation of volatiles through a scaling parameter to the dry adiabat. By combining these assumptions, we produce simple, analytic expressions that allow calculations of the atmospheric pressure-temperature profile, as well as expressions for the profiles of thermal radiative flux and convective flux. We explore the general behaviors of our model. These investigations encompass (1) worlds where atmospheric attenuation of sunlight is weak, which we show tend to have relatively high radiative-convective boundaries, (2) worlds with some attenuation of sunli...

  19. Solar and infrared radiation measurements

    CERN Document Server

    Vignola, Frank; Michalsky, Joseph

    2012-01-01

    The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operati

  20. Upper Atmosphere Humidity Measurement with Drycap Sensor

    OpenAIRE

    Lehtola, Terhi Johanna

    2014-01-01

    Atmospheric water vapor is a significant greenhouse gas. To gain proper understanding of the impact of water vapor on the climate, atmospheric water vapor profiles should be measured with high precision and accuracy. Due to challenging environmental conditions including extremely low temperatures and humidity concentrations, few research grade instruments are capable of measuring humidity accurately in upper troposphere and stratosphere. Laborious utilization or inadequate resolution of the e...

  1. Ground truth data for test sites (SL-3). [solar radiation and thermal radiation brightness temperature measurements

    Science.gov (United States)

    1974-01-01

    Field measurements performed simultaneously with Skylab overpasses in order to provide comparative calibration and performance evaluation measurements for the EREP sensors are presented. The solar radiation region from 400 to 1300 nanometers and the thermal radiation region from 8 to 14 micrometer region were investigated. The measurements of direct solar radiation were analyzed for atmospheric optical depth; the total and reflected solar radiation were analyzed for target reflectivity. These analyses were used in conjunction with a radiative transfer computer program in order to calculate the amount and spectral distribution of solar radiation at the apertures of the EREP sensors. The instrumentation and techniques employed, calibrations and analyses performed, and results obtained are discussed.

  2. Pyroelectric detector development for the Radiation Measurement system

    Science.gov (United States)

    Hubbard, G. S.; Mcmurray, Robert E., Jr.; Hanel, R. P.; Dominguez, D. E.; Valero, F. P. J.; Baumann, Hilary; Hansen, W. L.; Haller, E. E.

    1993-01-01

    A new class of high detectivity pyroelectric detectors developed for optimization of the radiation measurement system within the framework of the Atmospheric Radiation Measurement program is described. These devices are intended to provide detectivities of up to about 10 exp 11 cm Hz exp 0.5/W with cooling to about 100 K required for the detector focal plane.

  3. High-resolution terahertz atmospheric water vapor continuum measurements

    Science.gov (United States)

    Slocum, David M.; Goyette, Thomas M.; Giles, Robert H.

    2014-05-01

    The terahertz frequency regime is often used as the `chemical fingerprint' region of the electromagnetic spectrum due to the large number of rotational and vibrational transitions of many molecules of interest. This region of the spectrum has particular utility for applications such as pollution monitoring and the detection of energetic chemicals using remote sensing over long path lengths through the atmosphere. Although there has been much attention to atmospheric effects over narrow frequency windows, accurate measurements across a wide spectrum are lacking. The water vapor continuum absorption is an excess absorption that is unaccounted for in resonant line spectrum simulations. Currently a semiempirical model is employed to account for this absorption, however more measurements are necessary to properly describe the continuum absorption in this region. Fourier Transform Spectroscopy measurements from previous work are enhanced with high-resolution broadband measurements in the atmospheric transmission window at 1.5THz. The transmission of broadband terahertz radiation through pure water vapor as well as air with varying relative humidity levels was recorded for multiple path lengths. The pure water vapor measurements provide accurate determination of the line broadening parameters and experimental measurements of the transition strengths of the lines in the frequency region. Also these measurements coupled with the atmospheric air measurements allow the water vapor continuum absorption to be independently identified at 1.5THz. Simulations from an atmospheric absorption model using parameters from the HITRAN database are compared with the current and previous experimental results.

  4. Measurement and detection of radiation

    CERN Document Server

    Tsoulfanidis, Nicholas

    2011-01-01

    This is an update of the standard textbook for the field of radiation measurement. It includes illustrative examples and new problems. The research and applications of nuclear instrumentation have grown substantially since publication of the previous editions. With the miniaturization of equipment, increased speed of electronic components, and more sophisticated software, radiation detection systems are now more productively used in many disciplines, including nuclear nonproliferation, homeland security, and nuclear medicine. Continuing in the tradition of its bestselling predecessors, "Measurement and Detection of Radiation, Third Edition" illustrates the fundamentals of nuclear interactions and radiation detection with a multitude of examples and problems. It offers a clearly written, accessible introduction to nuclear instrumentation concepts. The following are new to the third edition: a new chapter on the latest applications of radiation detection, covering nuclear medicine, dosimetry, health physics, no...

  5. Nuclear instrumentation for radiation measurement

    International Nuclear Information System (INIS)

    Nuclear radiation cannot be detected by human senses. Nuclear detectors and associated electronics facilitate detection and measurement of different types of radiation like alpha particles, beta particles, gamma radiation, and detection of neutrons. Nuclear instrumentation has evolved greatly since the discovery of radioactivity. There has been tremendous advancement in detector technology, electronics, computer technology, and development of efficient algorithms and methods for spectral processing to extract precisely qualitative and quantitative information of the radiation. Various types of detectors and nuclear instruments are presently available and are used for different applications. This paper describes nuclear radiation, its detection and measurement and associated electronics, spectral information extraction, and advances in these fields. The paper also describes challenges in this field

  6. The Great Plains low-level jet (LLJ) during the atmospheric radiation measurement (ARM) intensive observation period (IOP)-4 and simulations of land use pattern effect on the LLJ

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The Great Plains low-level jet (LLJ) is an important element of the low-level atmospheric circulation. It transports water vapor from the Gulf of Mexico, which in turn affects the development of weather over the Great Plains of the central United States. The LLJ is generally recognized as a complex response of the atmospheric boundary layer to the diurnal cycle of thermal forcing. Early studies have attributed the Great Plains LLJ to the diurnal oscillations of frictional effect, buoyancy over sloping terrain, and the blocking effects of the Rocky Mountains. Recent investigations show that the speed of the LLJ is also affected by the soil type and soil moisture. Some studies also suggest that synoptic patterns may play an important role in the development of the LLJ. Land surface heterogeneties significantly affect mesoscale circulations by generating strong contrasts in surface thermal fluxes. Thus one would expect that the land use pattern should have effects on the LLJ`s development and structure. In this study, we try to determine the relative roles of the synoptic forcing, planetary boundary layers (PBL) processes, and the land use pattern in the formation of the LLJ using the observations from the Atmospheric Radiation Measurement (ARM) Intensive Operation Period (IOP)-4 and numerical sensitivity tests.

  7. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    OpenAIRE

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest ad...

  8. Radiative characteristics for atmospheric models from lidar sounding and AERONET

    Science.gov (United States)

    Sapunov, Maxim; Kuznetsov, Anatoly; Efremenko, Dmitry; Bochalov, Valentin; Melnikova, Irina; Samulenkov, Dimity; Vasilyev, Alexander; Poberovsky, Anatoly; Frantsuzova, Inna

    2016-04-01

    Optical models of atmospheric aerosols above of St. Petersburg are constraint on the base of the results of lidar sounding. The lidar system of the Resource Center "Observatory of environmental safety" of the St. Petersburg University Research Park is situated the city center, Vasilievsky Island. The measurements of the vertical profile of velocity and wind direction in the center of St. Petersburg for 2014 -2015 are fulfilled in addition. Height of laser sounding of aerosols is up to 25 km and wind up to 12 km. Observations are accomplished in the daytime and at night and mapped to vertical profiles of temperature, humidity, wind speed and pressure obtained from radiosounding in Voeikovo (St. Petersburg suburb). Results of wind observations are compared with those of upper-air measurements of meteorological service in Voeikovo. The distance between the points of observation is 25 km. Statistics of wind directions at different heights are identified. The comparison is based on the assumption of homogeneity of the wind field on such a scale. In most cases, good agreement between the observed vertical profiles of wind, obtained by both methods is appeared. However, there were several cases, when the results differ sharply or at high altitudes, or, on the contrary, in the surface layer. The analysis of the impact of wind, temperature, and humidity profiles in the atmosphere on the properties and dynamics of solid impurities is implemented. Comparison with AOT results from AERONET observations in St. Petersburg suburb Peterhof is done. It is shown that diurnal and seasonal variations of optical and morphological parameters of atmospheric aerosols in the pollution cap over the city to a large extent determined by the variability of meteorological parameters. The results of the comparison are presented and possible explanation of the differences is proposed. Optical models of the atmosphere in day and night time in different seasons are constructed from lidar and AERONET

  9. Stable isotope measurements of atmospheric CO2

    International Nuclear Information System (INIS)

    The measurement of stable carbon isotope ratios of atmospheric carbon dioxide, δ13CO2 are useful for partitioning surface-atmospheric fluxes into terrestrial and oceanic components. δC18OO also has potential for segregating photosynthetic and respiratory fluxes in terrestrial ecosystems. Here we describe in detail the techniques for making these measurements. The primary challenge for all of the techniques used to measure isotopes of atmospheric CO2 is to achieve acceptable accuracy and precision and to maintain them over the decades needed to observe carbon cycle variability. The keys to success such an approach are diligent intercalibrations of laboratories from around the world, as well as the use of multiple techniques such as dual inlet and GC-IRMS and the intercomparison of such measurements. We focus here on two laboratories, the Stable Isotope Lab at the Institute for Arctic and Alpine Research (INSTAAR) at the University of Colorado is described and the Commonwealth Scientific and Industrial Research Organisation - Atmospheric Research (CSIRO). Different approaches exist at other laboratories (e.g. programs operated by Scripps Institution of Oceanography (SIO) and The Center for Atmospheric and Oceanic Studies, Toboku University (TU)) however these are not discussed here. Finally, we also discuss the recently developed Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) technique which holds significant promise for measuring ultra-small samples of gas with good precision. (author)

  10. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.

    Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  11. Diffuse Sky Radiation in a Dry Turbid Atmosphere

    OpenAIRE

    R. A. Gupta; B. K. Agarwal

    1984-01-01

    Development of a simple method for the assessment of atmospheric turbidity all over the country in all seasons has been attempted. We have been able to derive a reasonably reliable equation relating diffuse sky radiation Dr on a horizontal surface to air mass mr and Angstrom Schuepp turbidity coefficient B, in a dry atmosphere with constant albedo (A = 0.25) of the terrain.

  12. A Consummate Radiative Transfer Package for Studying the Atmosphere and Oceans

    Science.gov (United States)

    Zhai, P.; Hu, Y.; Trepte, C. R.; Winker, D. M.

    2015-12-01

    We will present a radiative transfer package based on the successive order of scattering method. This code is capable to calculate the radiation field in turbid media, which can be either the atmosphere-land or atmosphere-ocean coupled systems. The outputs include all four Stokes parameters at arbitrary detector locations and viewing angles in the turbid medium. Both the elastic and inelastic scattering are implemented in the package. This radiative transfer tool has been used in various applications, for instance, generating an aerosol look-up table for atmospheric correction in ocean color remote sensing; retrieving water cloud size distribution using the polarized multi-angle measurements; simulating the OCO2 O2 A band radiance measurement, etc. Our radiative transfer package is a great tool to interpret and predict the measurements from the future polarimeters and multipolarization-state lidars for Earth observing missions.

  13. Radiation measurements and quality control

    International Nuclear Information System (INIS)

    Accurate measurements are essential to research leading to a successful radiation process and to the commissioning of the process and the facility. On the other hand, once the process is in production, the importance to quality control of measuring radiation quantities (i.e., absorbed dose, dose rate, dose distribution) rather than various other parameters of the process (i.e. conveyor speed, dwell time, radiation field characteristics, product dimensions) is not clearly established. When the safety of the product is determined by the magnitude of the administered dose, as in radiation sterilization, waste control, or food preservation, accuracy and precision of the measurement of the effective dose are vital. Since physical dose measurements are usually simpler, more reliable and reproducible than biological testing of the product, there is a trend toward using standardized dosimetry for quality control of some processes. In many industrial products, however, such as vulcanized rubber, textiles, plastics, coatings, films, wire and cable, the effective dose can be controlled satisfactorily by controlling process variables or by product testing itself. In the measurement of radiation dose profiles by dosimetry, it is necessary to have suitable dose meter calibrations, to account for sources of error and imprecision, and to use correct statistical procedures in specifying dwell times or conveyor speeds and source and product parameters to achieve minimum and maximum doses within specifications. (author)

  14. Computational study of atmospheric transfer radiation on an equatorial tropical desert (La Tatacoa, Colombia)

    CERN Document Server

    Delgado-Correal, Camilo; Castaño, Gabriel

    2012-01-01

    Radiative transfer models explain and predict interaction between solar radiation and the different elements present in the atmosphere, which are responsible for energy attenuation. In Colombia there have been neither measurements nor studies of atmospheric components such as gases and aerosols that can cause turbidity and pollution. Therefore satellite images cannot be corrected radiometrically in a proper way. When a suitable atmospheric correction is carried out, loss of information is avoided, which may be useful for discriminating image land cover. In this work a computational model was used to find radiative atmospheric attenuation (300 1000nm wavelength region) on an equatorial tropical desert (La Tatacoa, Colombia) in order to conduct an adequate atmospheric correction.

  15. A new thoron atmosphere reference measurement system.

    Science.gov (United States)

    Sabot, B; Pierre, S; Michielsen, N; Bondiguel, S; Cassette, P

    2016-03-01

    A new thoron reference ((220)Rn) in air measurement system is developed at the LNE-LNHB with the collaboration of the IRSN. This measurement system is based on a reference volume with an alpha detector which is able to directly measure thoron and its decay products at atmospheric pressure. In order to improve the spectrum quality of the thoron progenies, we have applied an electric field to catch the decay products on the detector surface. The developed system is a portative device which can be used to measure reference thoron atmosphere such as the BACCARA chamber at IRSN (Picolo et al., 1999). As this system also allows the measurement of radon ((222)Rn) in air, it was validated using the radon primary standards made at the LNE-LNHB. This thoron measurement system will be used, at IRSN, as a reference instrument in order to calibrate the thoron activity concentration in the BACCARA facility. PMID:26701661

  16. Current topics in radiation measurements

    International Nuclear Information System (INIS)

    Current research topics in radiation measurements will be shown in this presentation. Applications of radiation measurements have grown with the development of radiation sources and new measurement techniques. Recent new developments in this field are briefly introduced. Optical techniques such as lasers and fiber optics, which are widely used in an optical communication field, are successfully applied to radiation measurements. Micro-fabrication techniques and the photolithography technique are indispensable for semiconductor or even gas detectors. Complicated analog signal processing is being simplified by the use of fast computation techniques available in digital chips. Cryogenic X-ray detectors are making a great progress in the energy resolution. Some of the current research topics found in the recent journals and international symposiums are as follows: the development of room temperature semiconductor radiation detectors like CdZnTe and SiC, new signal processing methods such as coplanar grid unipolar charge sensing, medical γ-ray imaging, the development of cryogenic X-ray detectors such as STJs (Superconducting Tunnel Junction) and TES (Transition Edge Sensor) microcalorimeters, micromachined gas proportional counters like MSGC/MGC/GEM, new detection system which requires both the energy and spatial resolutions, the search of longer wavelength scintillators, development of new fast scintillators such as LSO/YAP/LuAP, new digital waveform processing based on fast digitizing technique, etc. Current developments are especially focused on the increase of the information derived from the detector and the improvement in the resolution. One of the other directions of the development is toward the microscopic visualization of the radiation. Such an approach must solve many technological difficulties both in fabrication of the detectors and even in the detection scheme, however, we might proceed to open a new phase of radiation measurements soon. (author)

  17. Quality assurance in radiation measurement

    International Nuclear Information System (INIS)

    The achievement of traceability to recognize measurement standards for ionizing radiation posses special requirements. Methods of transferring reference standard to the working situation are devised through calibration and appropriate traceability, which optimize the accuracy attainable with the method of dose determination in routine use. Appropriate procedures are developed by the SSDL-MINT to establish accurate dose measurement in wide range of radiation fields such as in medicine, agriculture and industrial application. The status of work including effort towards ISO 9000 certification of SSDL dosimetry services will be summarized. (Author)

  18. Radiation measurements and quality control

    International Nuclear Information System (INIS)

    The association between radiation measurements and quality control is established for radiation sterilization of medical products and food irradiation. Good quality control implies accurate radiation dosimetry and a discussion of the factors which can affect the accuracy of in-plant dosimetry is presented. It is argued that if systematic errors are to be avoided in in-plant dosimetry the plant operators will have to spend more time and effort in developing the skills associated with the accurate use of radiation dosemeter systems. The aims and merits of an international intercomparison programme recently set up by the IAEA are discussed. The benefits of accurate in-plant dosimetry for the operator, approving authority and purchaser are balanced against the extra dosimetric efforts required for good quality control. (author)

  19. FMCW Radar Performance for Atmospheric Measurements

    Directory of Open Access Journals (Sweden)

    T. Ince

    2010-04-01

    Full Text Available Frequency-modulated continuous-wave radars (FMCW have been used in the investigation of the atmosphere since the late 1960’s. FMCW radars provide tremendous sensitivity and spatial resolution compared to their pulsed counterparts and are therefore attractive for clear-air remote-sensing applications. However, these systems have some disadvantages and performance limitations that have prevented their widespread use by the atmospheric science community. In this study, system performance of atmospheric FMCW radar is analyzed and some measurement limitations for atmospheric targets are discussed. The effects of Doppler velocities and spectral widths on radar performance, radar’s near-field operation, and parallax errors for two-antenna radar systems are considered. Experimental data collected by the highresolution atmospheric FMCW radar is used to illustrate typical performance qualitatively based on morphological backscattered power information. A post-processing based on single-lag covariance differences between the Bragg and Rayleigh echo is applied to estimate clear-air component from refractive index turbulence and perform quantitative analysis of FMCW radar reflectivity from atmospheric targets.

  20. Atmospheric absorption of terahertz radiation and water vapor continuum effects

    International Nuclear Information System (INIS)

    The water vapor continuum absorption spectrum was investigated using Fourier Transform Spectroscopy. The transmission of broadband terahertz radiation from 0.300 to 1.500 THz was recorded for multiple path lengths and relative humidity levels. The absorption coefficient as a function of frequency was determined and compared with theoretical predictions and available water vapor absorption data. The prediction code is able to separately model the different parts of atmospheric absorption for a range of experimental conditions. A variety of conditions were accurately modeled using this code including both self and foreign gas broadening for low and high water vapor pressures for many different measurement techniques. The intensity and location of the observed absorption lines were also in good agreement with spectral databases. However, there was a discrepancy between the resonant line spectrum simulation and the observed absorption spectrum in the atmospheric transmission windows caused by the continuum absorption. A small discrepancy remained even after using the best available data from the literature to account for the continuum absorption. From the experimental and resonant line simulation spectra the air-broadening continuum parameter was calculated and compared with values available in the literature. -- Highlights: •Broadband absorption measurements of water vapor were performed at 300–1500 GHz. •The absorption coefficient of water vapor was modeled and compared with data. •The air-broadened continuum coefficient for water vapor was determined. •The modeled absorption coefficient is presented for 10–90% humidity at 0–3 THz

  1. Radiation Transfer Model for Aerosol Events in the Earth Atmosphere

    Science.gov (United States)

    Mukai, Sonoyo; Yokomae, Takuma; Nakata, Makiko; Sano, Itaru

    Recently large scale-forest fire, which damages the Earth environment as biomass burning and emission of carbonaceous particles, frequently occurs due to the unstable climate and/or global warming tendency. It is also known that the heavy soil dust is transported from the China continent to Japan on westerly winds, especially in spring. Furthermore the increasing emis-sions of anthropogenic particles associated with continuing economic growth scatter serious air pollutants. Thus atmospheric aerosols, especially in Asia, are very complex and heavy loading, which is called aerosol event. In the case of aerosol events, it is rather difficult to do the sun/sky photometry from the ground, however satellite observation is an effective for aerosol monitoring. Here the detection algorithms from space for such aerosol events as dust storm or biomass burn-ing are dealt with multispectral satellite data as ADEOS-2/GLI, Terra/Aqua/MODIS and/or GOSAT/CAI first. And then aerosol retrieval algorithms are examined based on new radiation transfer code for semi-infinite atmosphere model. The derived space-based results are validated with ground-based measurements and/or model simulations. Namely the space-or surface-based measurements, multiple scattering calculations and model simulations are synthesized together for aerosol retrieval in this work.

  2. Accuracy of Lidar Measurements of the Atmosphere

    Science.gov (United States)

    Kavaya, M. J.; Menzies, R. T.

    1986-01-01

    Report reviews sources of systematic error in laser radar (lidar) measurements of particles in atmosphere. Report applies particularly to stationary pulsed carbon dioxide lidars of type used to measure backscatter from aerosols in troposphere. Provides information for calibrating such systems accurately and consistently and interpreting their data correctly. Also useful in calibrating mobile and airborne lidars, lidars operating at wavelengths other than those of carbon dioxide lasers, and continuouswave lidars.

  3. Indirect determination of single scattering albedo and complex refractive index of atmospheric aerosol from combined spectral sun- and sky-radiance- as well spectral radiation flux-measurements and determination of radiative forcing. Final report; Indirekte Bestimmung der Single Scattering Albedo und des komplexen Brechungsindex des atmosphaerischen Aerosols aus kombinierten spektralen Sonnen- und Himmelsstrahlungs- sowie spektralen Strahlungsflussmessungen und Ermittlung des Strahlungsantriebs. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hoyningen-Huene, W. von; Burrows, J.P.; Schmidt, T.; Freitag, M.; Waltersdorf, M.; Roth, S.

    2001-07-01

    The insufficient knowledge of radiation parameters of the atmospheric aerosol yields a highly insufficient evaluation of the aerosol impact in different tasks. Climate research (determination of radiative forcing by aerosols), environmental control and monitoring (determination of aerosol impact), satellite remote sensing (atmospheric correction) and aerosol research (radiative properties) require the exact knowledge and complete data sets of optical aerosol parameters. During the closure experiment LACE-98 the main radiative aerosol parameters have been derived experimentally by closure of different atmospheric radiation measurements: spectral aerosol optical thickness, phase function and single scattering albedo. The use of spectral down-welling flux measurements enables the determination of spectral single scattering albedo. Radiative transfer calculations with these parameters have been used for the determination of the top-of-atmosphere radiance to be compared with satellite data (SeaWiFS). Resulting from these comparisons a dynamical surface reflectance model for land surfaces has been derived used in a retrieval procedure for the determination of the aerosol optical thickness from top-of-atmosphere reflectance from multi-spectral satellite data, applicable over land surface. The optical aerosol parameters, the retrieval procedure developed and the obtained regional distribution of the aerosol optical thickness over Germany are presented. (orig.) [German] Die unzureichende Kenntnis von strahlungsrelevanten Aerosolparametern fuehrt zu hohen Unsicherheiten bei der Bewertung des Aerosoleinflusses in verschiedenen Aufgabenbereichen. Klimaforschung (Bestimmung des Strahlungsantriebs durch Aerosole), Umweltkontrolle und Ueberwachung (Bestimmung des Aerosolimpakts), Fernerkundung (Atmosphaerenkorrektur) und Aerosolforschung (Strahlungseigenschaften) benoetigten exakte Kenntnis und komplette Saetze von optischen Aerosolparametern. Durch Schliessung verschiedener

  4. Measuring atmospheric neutrino oscillations with neutrino telescopes

    International Nuclear Information System (INIS)

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments

  5. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    CERN Document Server

    Albuquerque, I F M; Albuquerque, Ivone F.M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely-instrumented strings to the AMANDA II detector makes observations feasible. Such a configuration is competitive with current and proposed experiments.

  6. Measuring atmospheric neutrino oscillations with neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-09-01

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments.

  7. International radiation commissions 1896 to 2008. Research into atmospheric radiation from IMO to IAMAS

    International Nuclear Information System (INIS)

    The document covers a historical compilation on research into atmospheric radiation from 1896 to 2008. The first part is a brief history of the radiation commissions of IMO (International Meteorological Organization) and IUGG (International Union of Geodesy and Geophysics) for the period 1824 to 1948. Part 2 Covers the International Radiation Commission (IRC) of IAM (International Association of Meteorology)/IAMAS (International Association of Meteorology and Atmospheric Sciences)/IAMAP (International Association of Meteorology and Atmospheric Physics); the Re-constitution of the IUGG Radiation Commision, the Officers of the International Radiation Commission of IUUG 1948-2008, and the activities of the Radiation Commision of the IUGG 1948-2008. The appendices include the Radiation Commission Members, the summaries of presented papers from 1954 and 1957, the IRC publications, and acronyms

  8. International radiation commissions 1896 to 2008. Research into atmospheric radiation from IMO to IAMAS

    Energy Technology Data Exchange (ETDEWEB)

    Bolle, H.J. (comp.); Moeller, F.; London, J.

    2008-05-15

    The document covers a historical compilation on research into atmospheric radiation from 1896 to 2008. The first part is a brief history of the radiation commissions of IMO (International Meteorological Organization) and IUGG (International Union of Geodesy and Geophysics) for the period 1824 to 1948. Part 2 Covers the International Radiation Commission (IRC) of IAM (International Association of Meteorology)/IAMAS (International Association of Meteorology and Atmospheric Sciences)/IAMAP (International Association of Meteorology and Atmospheric Physics); the Re-constitution of the IUGG Radiation Commision, the Officers of the International Radiation Commission of IUUG 1948-2008, and the activities of the Radiation Commision of the IUGG 1948-2008. The appendices include the Radiation Commission Members, the summaries of presented papers from 1954 and 1957, the IRC publications, and acronyms.

  9. Structure of the Venus atmosphere in accordance with optical measurements carried out at Venera-11,13,14 landing apparatus

    International Nuclear Information System (INIS)

    A strict theory of the radiation transport in the multilayer atmosphere is used for the interpretation of Venera 11, 13 and 14 measurements of radiation field in the Venus atmosphere. For the spectral interval 0.45-1.01 μm the optical parameters of the atmosphere are determined. A comparison with previous results obtained mainly by means of approximate methods is given

  10. Intercomparison of Shortwave Radiative Transfer Codes and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Halthore, Rangasayi N.; Crisp, David; Schwartz, Stephen E.; Anderson, Gail; Berk, A.; Bonnel, B.; Boucher, Olivier; Chang, Fu-Lung; Chou, Ming-Dah; Clothiaux, Eugene E.; Dubuisson, P.; Fomin, Boris; Fouquart, Y.; Freidenreich, S.; Gautier, Catherine; Kato, Seiji; Laszlo, Istvan; Li, Zhanqing; Mather, Jim H.; Plana-Fattori, Artemio; Ramaswamy, V.; Ricchiazzi, P.; Shiren, Y.; Trishchenko, A.; Wiscombe, Warren J.

    2005-06-03

    Computation of components of shortwave (SW) or solar irradiance in the surface-atmospheric system forms the basis of intercomparison between 16 radiative transfer models of varying spectral resolution ranging from line-by-line models to broadband and general circulation models. In order of increasing complexity the components are: direct solar irradiance at the surface, diffuse irradiance at the surface, diffuse upward flux at the surface, and diffuse upward flux at the top of the atmosphere. These components allow computation of the atmospheric absorptance. Four cases are considered from pure molecular atmospheres to atmospheres with aerosols and atmosphere with a simple uniform cloud. The molecular and aerosol cases allow comparison of aerosol forcing calculation among models. A cloud-free case with measured atmospheric and aerosol properties and measured shortwave radiation components provides an absolute basis for evaluating the models. For the aerosol-free and cloud-free dry atmospheres, models agree to within 1% (root mean square deviation as a percentage of mean) in broadband direct solar irradiance at surface; the agreement is relatively poor at 5% for a humid atmosphere. A comparison of atmospheric absorptance, computed from components of SW radiation, shows that agreement among models is understandably much worse at 3% and 10% for dry and humid atmospheres, respectively. Inclusion of aerosols generally makes the agreement among models worse than when no aerosols are present, with some exceptions. Modeled diffuse surface irradiance is higher than measurements for all models for the same model inputs. Inclusion of an optically thick low-cloud in a tropical atmosphere, a stringent test for multiple scattering calculations, produces, in general, better agreement among models for a low solar zenith angle (SZA = 30?) than for a high SZA (75?). All models show about a 30% increase in broadband absorptance for 30? SZA relative to the clear-sky case and almost no

  11. Ground truth data for test sites (SL-4). [thermal radiation brightness temperature and solar radiation measurments

    Science.gov (United States)

    1974-01-01

    Field measurements performed simultaneous with Skylab overpass in order to provide comparative calibration and performance evaluation measurements for the EREP sensors are presented. Wavelength region covered include: solar radiation (400 to 1300 nanometer), and thermal radiation (8 to 14 micrometer). Measurements consisted of general conditions and near surface meteorology, atmospheric temperature and humidity vs altitude, the thermal brightness temperature, total and diffuse solar radiation, direct solar radiation (subsequently analyzed for optical depth/transmittance), and target reflectivity/radiance. The particular instruments used are discussed along with analyses performed. Detailed instrument operation, calibrations, techniques, and errors are given.

  12. Isotope measurement techniques for atmospheric methane

    International Nuclear Information System (INIS)

    Measurement techniques for the carbon isotopic composition of atmospheric methane (δ13C) are described in detail as applied in several leading institutions active in this field since many years. The standard techniques with offline sample preparation and subsequent measurement by dual inlet isotope ratio mass spectrometry (IRMS) are compared with continuous flow IRMS. The potential use of infrared absorption spectroscopy is briefly discussed. Details on quality control and calibration are provided. Basic analytical aspects for the measurement of other species, 2H and 14C, are also given. (author)

  13. Diffuse Sky Radiation in a Dry Turbid Atmosphere

    Directory of Open Access Journals (Sweden)

    R. A. Gupta

    1984-07-01

    Full Text Available Development of a simple method for the assessment of atmospheric turbidity all over the country in all seasons has been attempted. We have been able to derive a reasonably reliable equation relating diffuse sky radiation Dr on a horizontal surface to air mass mr and Angstrom Schuepp turbidity coefficient B, in a dry atmosphere with constant albedo (A = 0.25 of the terrain.

  14. Transport of Ionizing Radiation in Terrestrial-like Exoplanet Atmospheres

    OpenAIRE

    Smith, David S.; Scalo, John; Wheeler, J. Craig

    2003-01-01

    (Abridged) The propagation of ionizing radiation through model atmospheres of terrestrial-like exoplanets is studied for a large range of column densities and incident photon energies using a Monte Carlo code we have developed to treat Compton scattering and photoabsorption. Incident spectra from parent star flares, supernovae, and gamma-ray bursts are modeled and compared to energetic particles in importance. We find that terrestrial-like exoplanets with atmospheres thinner than about 100 g ...

  15. The Havemann-Taylor Fast Radiative Transfer Code: Exact fast radiative transfer for scattering atmospheres using Principal Components (PCs)

    Science.gov (United States)

    Havemann, Stephan; Thelen, Jean-Claude; Taylor, Jonathan P.; Keil, Andreas

    2009-03-01

    The Havemann-Taylor Fast Radiative Transfer Code (HT-FRTC) has been developed for the simulation of highly spectrally resolved measurements from satellite based (i.e. Infrared Atmospheric Sounding Interferometer (IASI), Atmospheric Infrared Sounder (AIRS)) and airborne (i.e. Atmospheric Research Interferometer Evaluation System (ARIES)) instruments. The use of principle components enables the calculation of a complete spectrum in less than a second. The principal compoents are derived from a diverse training set of atmospheres and surfaces and contain their spectral characteristics in a highly compressed form. For any given atmosphere/surface, the HT-FRTC calculates the weightings (also called scores) of a few hundred principal components based on selected monochromatic radiative transfer calculations, which is far cheaper than thousands of channel radiance calculations. By intercomparison with line-by-line and other fast models the HT-FRTC has been shown to be accurate. The HT-FRTC has been successfully applied to simultaneous variational retrievals of atmospheric temperature and humidity profiles, surface temperature and surface emissivity over land. This is the subject of another presentation at this conference. The HT-FRTC has now also been extended to include an exact treatment of scattering by aerosols/clouds. The radiative transfer problem is solved using a discrete ordinate method (DISORT). Modelling results at high-spectral resolution for non-clear sky atmospheres obtained with the HT-FRTC are presented.

  16. Infrared spectroscopic measurements on planetary atmospheric gases

    International Nuclear Information System (INIS)

    Infrared spectroscopic measurements were performed on trace gas molecules known to be infrared-active in the atmospheres of Earth and the Outer Planets. The measurements were performed at low temperatures relevant to the planetary atmospheres employing the high spectral resolution attainable with a tunable diode laser spectrometer. Accurate data on the intensities, N(2-), O(2-), and air-broadened half-widths of lines in the nu(sub 1)-fundamental band (7.78 microns) of 14-N2O-16 were obtained at several temperatures between 185 and 296 K. These data are needed in remote sensing, ozone depletion, and climate modeling studies of the terrestrial atmosphere. The pressure-induced shifts of some 14-N2O-16 lines were also measured. Intensity data in the 10(sup 0)0-01(sup 1)0 band (13.87 microns) of 12-C16-O2 at 295 K which are useful in studies of the thermal structure of the Earth's atmosphere were measured. They differ significantly from previously published and cataloged data. Measurements of the absolute intensities and the H2-broadened half-widths of several spectral lines in the nu(sub 3) band of GeH4, which was detected in the atmospheres of the Outer Planets, were performed at low temperatures between 94 and 300 K. The combined intensity of the nu(sub 3) bands of all of the five isotopic species of GeH4 as well as that of the Q-branches alone were measured independently at 294 using the Wilson-Wells-Penner-Weber Technique. Absolute intensities, collision-broadened half-widths, and pressure-induced shifts of several lines in the nu(sub 4)-fundamental bands of 12-CH4 and 13-CH4 around 7.70 microns, the nu(sub 2)-fundamantal band of 12-CH3D at 4.55 microns, the nu(sub 3)-fundamental band of 12-CH3D at 7.76 microns, the nu(sub 6)-fundamental band of 12-CH3D at 8.61 microns, and the CO fundamental at 4.67 microns, all of which appear in the spectra of the Outer Planets, were measured at low temperatures

  17. Meso-Beta-Scale Data Assimilation of the Winter Icing and Storms Program/Atmospheric Radiation Measurement Program 91 intensive observing period case on 6 March 1991

    International Nuclear Information System (INIS)

    To support the ARM program, we have proposed to develop an Integrated Data Assimilation and Sounding System (IDASS). The IDASS is composed of a measurement component and a modeling component. The measurement component (Integrated Sounding System or ISS) is developed around a suite of in situ and active and passive remote sensors. Individually, these sensors satisfy certain needs, together they function in a synergistic and complementary mode. The modeling component is an enhanced nonhydrostatic version of the Penn State/NCAR mesoscale model with data assimilation capability. The goal of IDASS is to provide continuous high-resolution tropospheric profiles of basic meteorological variables by continuous assimilation of measurements taken by ISS. The objectives of this study are (1) to assess the impact of mesoscale data assimilation on the model results, and (2) to evaluate the basic concept of IDASS

  18. Radiochromic technique for radiation measurements

    International Nuclear Information System (INIS)

    he radio-chromic technique in radiation dosimetry for protection of patients and occupational workers are known to health physicist and dosimetrist since long. But with the recent advances in polymer science, measurement techniques and understanding of physical phenomenon responsible for color change on radiation sensitive objects, the technique is progressing very well for personal accidental dose measurements, online dose mapping of patients during radiotherapy treatment without any further processing, and radiation industries. These dosimeters, with very high spatial resolution and relatively low spectral sensitivity variation, are insensitive to visible light, thus offering ease of handling. Radiochromic dosimeters color directly and do not require chemical processing wherein a color change (colorless to blue, red, green, etc.) indicates exposure to radiation. Image formation occurs as a dye-forming or a polymerization process, in which energy is transferred from an energetic photon or particle to the receptive part of the leuco-dye or colorless photomonomer molecule, initiating color formation through chemical changes. In recent years, various radiochromic dosimeters have also been used for nonclinical applications such as blood irradiation, radiation processing, and reference standard. The Paper highlights the national and international status of the techniques including responsible physical - chemical phenomenon, standard commercial products with its futuristic applications for mapping of radiation doses and radiation dose estimation in nuclear/radiological emergency. The Paper highlights the R and D efforts carried out at DLJ to establish radiochromic techniques based on radiochromic dyes and substituted diacytelene first time in India. The radiochromic films based on pH sensitive dyes, leuco dyes and substituted diacytelene using a suitable polymer as a host matrix has been developed at DLJ and characterized using standard techniques. The radiochromic

  19. Measurements and correlations between several atmospheric parameters

    Directory of Open Access Journals (Sweden)

    Kolarž Predrag

    2008-01-01

    Full Text Available Diurnal atmospheric air-ion concentrations have been investigated at a site where synchronous aerosol, ozone, temperature and relative humidity measurements were also made. Air-ions, temperature and relative humidity were measured with Gerdien type Cylindrical Detector of Air-Ions (CDI-06 made in the Institute of Physics, Belgrade. Ozone and aerosols were measured with commercial instruments owned by the Institute of Public Health, Belgrade. Typical daily variations of the measured parameters were analyzed and showed that air-ions of both signs and ozone are positively correlated, while aerosols show strong inverse correlation with air-ions. Also, concentrations of air-ions and ozone are decreasing with temperature while aerosol concentration and humidity are increasing. These processes could be explained concerning properties of the specified parameters, measuring place properties and weather conditions.

  20. Global Measurements of Atmospheric Sulfuryl Fluoride

    Science.gov (United States)

    Mühle, J.; Harth, C. M.; Salameh, P.; Miller, B. R.; Weiss, R. F.; Porter, L. W.; Fraser, P. J.; Greally, B. R.; O'Doherty, S.

    2006-12-01

    Sulfuryl fluoride (SO2F2) is used increasingly as a fumigant, but information about its emissions to the atmosphere is limited. Its atmospheric fate and lifetime are uncertain, with hydrolysis in the basic surface waters of the oceans a likely dominant sink, and its roles as a greenhouse gas and as a sulfur source to the stratosphere are unknown. We present here the first results of two years of high-frequency high-precision in situ observations of sulfuryl fluoride in the AGAGE (Advanced Global Atmospheric Gases Experiment) global measurement program. At La Jolla, California, baseline conditions are rarely achieved, and pollution events of up to 1.7 ppb (the exposure limit is 5 ppm) from nearby structural fumigation are common. At the Mace Head, Ireland, and Cape Grim, Tasmania, AGAGE stations, baseline conditions are observed with mixing ratios at the beginning of 2005 of ~1.0 ppt and ~0.9 ppt, respectively. Measured growth rates at these stations are ~0.06 ppt per year and ~0.04 ppt per year, respectively. Using these preliminary results and assuming no significant emissions in the southern hemisphere, a simple 2-box model can be used to estimate the tropospheric lifetime of sulfuryl fluoride as about one and a half decades, which is substantially longer than previous industry estimates. The corresponding modeled sulfuryl fluoride flux to the troposphere is ~2 x 109 g per year. Based on these initial measurements, the current global warming contribution of sulfuryl fluoride is likely small. Although the lifetime of sulfuryl fluoride is longer than that of carbonyl sulfide, sulfuryl fluoride is likely less important as source of sulfur to the stratosphere, due to its low atmospheric mixing ratio.

  1. Future atmospheric neutrino measurements with PINGU

    International Nuclear Information System (INIS)

    Neutrino oscillations, first measured in 1998 via atmospheric neutrinos, have provided the only current direct evidence for physics beyond the Standard Model of Elementary Particles. The full neutrino mixing, described by six parameters, has been measured in the last decade with the exception of the charge-parity phase and the ordering of the mass eigenstates (the neutrino mass hierarchy – NMH). A relatively large mixing-angle between the first and third mass eigenstates has opened the possibility of measuring the mass hierarchy via atmospheric neutrinos using very large volume detectors. A leading proposal to perform this measurement is the future low-energy extension to the IceCube–DeepCore detector, called PINGU (the Precision IceCube Next Generation Upgrade). By increasing the photocathode density in the DeepCore region, it is possible to lower the energy threshold in the fiducial volume to the region that is affected by the MSW [1, 2], and thus permits extraction of the hierarchy. Here we discuss the design of the PINGU detector, its sensitivity to the mass hierarchy (approximately 3σ in 3.5 years) and measurements of νμ disappearance and ντ appearance

  2. Highly physical penumbra solar radiation pressure modeling with atmospheric effects

    Science.gov (United States)

    Robertson, Robert; Flury, Jakob; Bandikova, Tamara; Schilling, Manuel

    2015-10-01

    We present a new method for highly physical solar radiation pressure (SRP) modeling in Earth's penumbra. The fundamental geometry and approach mirrors past work, where the solar radiation field is modeled using a number of light rays, rather than treating the Sun as a single point source. However, we aim to clarify this approach, simplify its implementation, and model previously overlooked factors. The complex geometries involved in modeling penumbra solar radiation fields are described in a more intuitive and complete way to simplify implementation. Atmospheric effects are tabulated to significantly reduce computational cost. We present new, more efficient and accurate approaches to modeling atmospheric effects which allow us to consider the high spatial and temporal variability in lower atmospheric conditions. Modeled penumbra SRP accelerations for the Gravity Recovery and Climate Experiment (GRACE) satellites are compared to the sub-nm/s2 precision GRACE accelerometer data. Comparisons to accelerometer data and a traditional penumbra SRP model illustrate the improved accuracy which our methods provide. Sensitivity analyses illustrate the significance of various atmospheric parameters and modeled effects on penumbra SRP. While this model is more complex than a traditional penumbra SRP model, we demonstrate its utility and propose that a highly physical model which considers atmospheric effects should be the basis for any simplified approach to penumbra SRP modeling.

  3. Benchmark results in vector atmospheric radiative transfer

    International Nuclear Information System (INIS)

    In this paper seven vector radiative transfer codes are inter-compared for the case of underlying black surface. They include three techniques based on the discrete ordinate method (DOM), two Monte-Carlo methods, the successive orders scattering method, and a modified doubling-adding technique. It was found that all codes give very similar results. Therefore, we were able to produce benchmark results for the Stokes parameters both for reflected and transmitted light in the cases of molecular, aerosol and cloudy multiply scattering media. It was assumed that the single scattering albedo is equal to one. Benchmark results have been provided by several studies before, including Coulson et al., Garcia and Siewert, Wauben and Hovenier, and Natraj et al. among others. However, the case of the elongated phase functions such as for a cloud and with a high angular resolution is presented here for the first time. Also in difference with other studies, we make inter-comparisons using several codes for the same input dataset, which enables us to quantify the corresponding errors more accurately.

  4. Measurement of atmospheric ozone by cavity ring-down spectroscopy.

    Science.gov (United States)

    Washenfelder, R A; Wagner, N L; Dube, W P; Brown, S S

    2011-04-01

    Ozone plays a key role in both the Earth's radiative budget and photochemistry. Accurate, robust analytical techniques for measuring its atmospheric abundance are of critical importance. Cavity ring-down spectroscopy has been successfully used for sensitive and accurate measurements of many atmospheric species. However, this technique has not been used for atmospheric measurements of ozone, because the strongest ozone absorption bands occur in the ultraviolet spectral region, where Rayleigh and Mie scattering cause significant cavity losses and dielectric mirror reflectivities are limited. Here, we describe a compact instrument that measures O3 by chemical conversion to NO2 in excess NO, with subsequent detection by cavity ring-down spectroscopy. This method provides a simple, accurate, and high-precision measurement of atmospheric ozone. The instrument consists of two channels. The sum of NO2 and converted O3 (defined as Ox) is measured in the first channel, while NO2 alone is measured in the second channel. NO2 is directly detected in each channel by cavity ring-down spectroscopy with a laser diode light source at 404 nm. The limit of detection for O3 is 26 pptv (2 sigma precision) at 1 s time resolution. The accuracy of the measurement is ±2.2%, with the largest uncertainty being the effective NO2 absorption cross-section. The linear dynamic range of the instrument has been verified from the detection limit to above 200 ppbv (r2>99.99%). The observed precision on signal (2 sigma) with 41 ppbv O3 is 130 pptv in 1 s. Comparison of this instrument to UV absorbance instruments for ambient O3 concentrations shows linear agreement (r2=99.1%) with slope of 1.012±0.002. PMID:21366216

  5. Soil-Vegetation-Atmosphere Radiative Transfer Model in Microwave Region

    Institute of Scientific and Technical Information of China (English)

    JIA Yuanyuan; LI Zhaoliang

    2008-01-01

    The radiative transfer is one of the significant theories that describe the processes of scattering,emission,and absorption of electromagnetic radiant intensity through scattering medium.It is the basis of the study on the quantitative remote sensing.In this paper,the radiative characteristics of soil,vegetation,and atmosphere were described respectively.The numerical solution of radiative transfer was accomplished by Successive Orders of Scattering (SOS).A radiative transfer model for simulating microwave brightness temperature over land surfaces was constructed,designed,and implemented.Analyzing the database generated from soil-vegetation-atmosphere radiative transfer model under Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) configuration showed that the atmospheric effects on microwave brightness temperature should not be neglected,particularly for higher frequency,and can be parameterized.At the same time,the relationship between the emissivities of the different channels was developed.The study results will promote the development of algorithm to retrieve geophysical parameters from microwave remotely sensed data.

  6. Conversion coefficients for cosmic radiation in the atmosphere

    International Nuclear Information System (INIS)

    The main purpose of the present calculations was the evaluation of the fluence-to-effective dose conversion coefficients for cosmic radiation in the atmosphere. During their work air crew members are exposed to elevated ionising radiation from cosmic radiation which shall be determined. Cosmic radiation in the Earth's atmosphere exhibits a complex environment consisting of neutrons, protons, photons, electrons, positrons, pions, muons and heavy ions. Their energy range extends up to hundreds of GeV. To calculate the dose components from the particle fluences in the atmosphere, the effective dose conversion coefficients of all particle types produced by the galactic cosmic rays have to be determined. In the high energy range (approximately above 10 MeV) there is only a limited number of data available in the literature. Only INFN (Instituto Nazionale di Fisica Nucleare) in Italy has published a consistent set of fluence-to-effective dose conversion coefficients for all kinds of radiation and incident energies up to 10 TeV, calculated by the FLUKA transport code. The aim of this work is to validate these earlier calculations performed by FLUKA using the high energy code MCNPX and fill in the gaps in the conversion coefficients as a function of particle energy

  7. Equipment for measuring radiation. Part 3. Technique of measuring radiation

    Energy Technology Data Exchange (ETDEWEB)

    Radwanowski, L.J.

    1979-01-01

    Difficulties are noted in measuring the effects of radiation because of the excessively low energy of the measured fields. In nature there are different magnetic-dynamic and magnetic-hydrodynamic generators which are sources of very low intensity which changes in time. The equipment of measurements is examined in the example of one of the generators, underground water current. The apparatus is described in detail for measuring the intensity of the electromagnetic SHF field. Under the underground water currents a change is observed in the intensity of the electromagnetic field. The possibilities are also examined of direct measurement of ultrasonic elastic fluctuations caused by the underground current, as well as the possibility of recording other physical fields (spontaneous polarization, soil temperature). A study was made of the effect of the underground water current on the occurrence of physical, chemical and biological processes: photochemical reactions, reactions of metal oxidation, Golomb effect (change in the rate of sedimentation of argillaceous particles in water under the influence of a biofield), change in air humidity and soil water content, change in intensity of the magnetic field, Hall effect, change in luminescence of certain organisms or the luminophore released by them. Basic plans are presented of certain measurement and recording devices.

  8. First measurements of the Martian radiation environment

    International Nuclear Information System (INIS)

    The 2001 Mars Odyssey spacecraft has been returning data from Mars since February 2002. Its orbit is polar and nearly circular, about 400 km above the surface, with a two-hour period. Among the instruments onboard Odyssey are the Martian Radiation Environment Experiment (MARIE) and the Gamma Ray Spectrometer (GRS), which is a suite of instruments that includes several neutron detectors. This paper focuses on results from MARIE, which is measuring Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) at Mars in order to assess radiation health risks to future human explorers. MARIE is highly efficient for SPE, and for GCR in the charge range from 2 (helium) to 10 (neon); spectra obtained in this range are compared to data from the ACE/ CRIS detector and show good agreement. The SPE data obtained by MARIE are unique and may show effects due to 'magnetic anomalies,' regions of remanent magnetism on the Martian surface. Data from the Mars Global Surveyor magnetometer are used in this analysis. Although the GRS instruments are primarily intended to measure radiation from the Martian surface, both the gamma-ray detector and the neutron detectors provide valuable information about the local radiation environment at Mars. The gamma-ray crystal is useful in providing coverage during MARIE data outages, which arise due to limited storage space and tend to limit acquisition during SPE. The neutron detectors provide data that can, with modeling of neutron transport through the atmosphere, be used to predict surface neutron doses. The combined data from these instruments are giving a clear picture of the radiation environment at Mars and the potential risks that will be faced by humans who venture there

  9. Miniature detector measures deep space radiation

    Science.gov (United States)

    Schultz, Colin

    2011-08-01

    The 1972 journey of Apollo 17 marked not only the last time a human walked on the Moon but also the most recent manned venture beyond the outer reaches of the Earth's atmosphere. With preparations being made for humans to once again explore deep space, important steps are under way to quantify the hazards of leaving low-Earth orbit. One significant risk for long-distance missions is the increased exposure to ionizing radiation—energetic particles that can strip electrons off of otherwise neutral materials, affecting human health and the functioning of spacecraft equipment. The deep space probes that are being sent to measure the risks from ionizing radiation and other hazards can be costly, so maximizing the scientific value of each launch is important. With this goal in mind, Mazur et al. designed and developed a miniature dosimeter that was sent into lunar orbit aboard NASA's Lunar Reconnaissance Orbiter (LRO) in 2009. Weighing only 20 grams, the detector is able to measure fluctuations in ionizing radiation as low as 1 microrad (equivalent to 1.0 × 10-8 joules of energy deposited into 1 kilogram) while requiring minimal power and computer processing. The postage stamp-sized detector tracked radiation dosages for the first year of LRO's mission, with the results being confirmed by other onboard and near-Earth detectors. (Space Weather, doi:10.1029/2010SW000641, 2011)

  10. Alternative application for the radiation background in the development of the atlas database of atmospheric radiation

    CERN Document Server

    De la Hoz, Ivan Arturo Morales

    2014-01-01

    Nowadays radiation is one of the variables to be considered in the environmental forecasting and it is meaningful in the increase of global warming, together greenhouse effect. The radiation considered by the meteorological organizations depends on the World Radiometric Reference (WRR), the World Standard Group (WSG), addressed by the World Meteorological Organization (WMO). This work is based on the cosmic microwave background, as a variable to be estimated in order to get information about the incident radiation in the Earth's atmosphere, as a valuable and meaningful contribution in the building of the radiation atlas by the (UPME) and (IDEAM). Due to the fact that the variables considered are ultraviolet and infrared radiation, ozone column, direct radiation and diffuse radiation, the last two get the global radiation, and are the only ones to be evaluated by the national meteorological organizations in the country. The study of the cosmic background radiation as a research project will provide data which ...

  11. SUMER: Solar Ultraviolet Measurements of Emitted Radiation

    Science.gov (United States)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, S. D.; Kuehne, M.; Lemaire, P.; Marsch, E.

    1992-01-01

    The experiment Solar Ultraviolet Measurements of Emitted Radiation (SUMER) is designed for the investigations of plasma flow characteristics, turbulence and wave motions, plasma densities and temperatures, structures and events associated with solar magnetic activity in the chromosphere, the transition zone and the corona. Specifically, SUMER will measure profiles and intensities of Extreme Ultraviolet (EUV) lines emitted in the solar atmosphere ranging from the upper chromosphere to the lower corona; determine line broadenings, spectral positions and Doppler shifts with high accuracy, provide stigmatic images of selected areas of the Sun in the EUV with high spatial, temporal and spectral resolution and obtain full images of the Sun and the inner corona in selectable EUV lines, corresponding to a temperature from 10,000 to more than 1,800,000 K.

  12. Brown carbon: a significant atmospheric absorber of solar radiation?

    Directory of Open Access Journals (Sweden)

    Y. Feng

    2013-01-01

    Full Text Available Several recent observational studies have shown organic carbon aerosols to be a significant source of absorption of solar radiation. The absorbing part of organic aerosols is referred to as brown carbon. Comparisons with observations indicate that model-simulated aerosol absorption is under-estimated in global models, one of the reasons being the neglect of brown carbon. Using a global chemical transport model coupled with a radiative transfer model, we estimate for the first time the enhanced absorption of solar radiation due to "brown" carbon (BrC in a global model. When BrC is included, the simulated wavelength dependence of aerosol absorption, as measured by the Angstrom exponent increases from 0.9 to 1.2 and thus agrees better with AERONET spectral observations at 440–870 nm. The resulting absorbing aerosol optical depth increases by 3–18% at 550 nm and up to 56% at 350 nm. The global simulations suggest that BrC contributes up to +0.25 W m−2 or 19% of the absorption by anthropogenic aerosols, of which 72% is attributed to black carbon, and 9% is due to sulfate and non-absorbing organic aerosols coated on black carbon. Like black carbon, the overall forcing of BrC at the top of the atmosphere (TOA is a warming effect (+0.11 W m−2, while the effect at the surface is a reduction or dimming (−0.14 W m−2. Because of the inclusion of BrC in our model, the direct radiative effect of organic carbonaceous aerosols changes from cooling (−0.08 W m−2 to warming (+0.025 W m−2 at the TOA, on a global mean basis. Over source regions and above clouds, the absorption of BrC is more significant and thus can play an important role in photochemistry and the hydrologic cycle.

  13. Brown carbon: a significant atmospheric absorber of solar radiation?

    Directory of Open Access Journals (Sweden)

    Y. Feng

    2013-09-01

    Full Text Available Several recent observational studies have shown organic carbon aerosols to be a significant source of absorption of solar radiation. The absorbing part of organic aerosols is referred to as "brown" carbon (BrC. Using a global chemical transport model and a radiative transfer model, we estimate for the first time the enhanced absorption of solar radiation due to BrC in a global model. The simulated wavelength dependence of aerosol absorption, as measured by the absorption Ångström exponent (AAE, increases from 0.9 for non-absorbing organic carbon to 1.2 (1.0 for strongly (moderately absorbing BrC. The calculated AAE for the strongly absorbing BrC agrees with AERONET spectral observations at 440–870 nm over most regions but overpredicts for the biomass burning-dominated South America and southern Africa, in which the inclusion of moderately absorbing BrC has better agreement. The resulting aerosol absorption optical depth increases by 18% (3% at 550 nm and 56% (38% at 380 nm for strongly (moderately absorbing BrC. The global simulations suggest that the strongly absorbing BrC contributes up to +0.25 W m−2 or 19% of the absorption by anthropogenic aerosols, while 72% is attributed to black carbon, and 9% is due to sulfate and non-absorbing organic aerosols coated on black carbon. Like black carbon, the absorption of BrC (moderately to strongly inserts a warming effect at the top of the atmosphere (TOA (0.04 to 0.11 W m−2, while the effect at the surface is a reduction (−0.06 to −0.14 W m−2. Inclusion of the strongly absorption of BrC in our model causes the direct radiative forcing (global mean of organic carbon aerosols at the TOA to change from cooling (−0.08 W m−2 to warming (+0.025 W m−2. Over source regions and above clouds, the absorption of BrC is higher and thus can play an important role in photochemistry and the hydrologic cycle.

  14. Atmospheric Measurements by the 2002 Geoscience Laser Altimeter System Mission

    Science.gov (United States)

    Spinhirne, James D.; Starr, David OC. (Technical Monitor)

    2002-01-01

    The NASA Earth Observing System (EOS) program is a multiple platform NASA initiative for the study of global change. As part of the EOS project, the Geoscience Laser Altimeter System (GLAS) was selected as a laser sensor filling complementary requirements for several earth science disciplines including atmospheric and surface applications. Late in 2002, the GaAs instrument is to be launched for a three to five year observational mission. For the atmosphere, the instrument is designed to full fill comprehensive requirements for profiling of radiatively significant cloud and aerosol. Algorithms have been developed to process the cloud and aerosol data and provide standard data products. After launch there will be a three-month project to analyze and understand the system performance and accuracy of the data products. As an EOS mission, the GaAs measurements and data products will be openly available to all investigators. An overview of the instrument, data products and evaluation plan is given.

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

    International Nuclear Information System (INIS)

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

  16. Processes linking the hydrological cycle and the atmospheric radiative budget

    Science.gov (United States)

    Fueglistaler, Stephan; Dinh, Tra

    2016-04-01

    We study the response of the strength of the global hydrological cycle to changes in carbon dioxide (CO2) using the HiRAM General Circulation Model developed at the Geophysical Fluid Dynamics Laboratory (GFDL), with the objective to better connect the well-known energetic constraints to physical processes. We find that idealized model setups using a global slab ocean and annual mean insolation give similar scalings as coupled atmosphere-ocean models with realistic land and topography. Using the surface temperatures from the slab ocean runs, we analyse the response in the atmospheric state and hydrological cycle separately for a change in CO2 (but fixed surface temperature), and for a change in surface temperature (but fixed CO2). The former perturbation is also referred to as the "fast" response, whereas the latter is commonly used to diagnose a model's climate sensitivity. As expected from the perspective of the atmospheric radiative budget, an increase in CO2 at fixed surface temperature decreases the strength of the hydrological cycle, and an increase in surface temperature increases the strength of the hydrological cycle. However, the physical processes that connect the atmospheric radiative energy budget to the sensible and latent heat fluxes at the surface remain not well understood. The responses to the two perturbations are linearly additive, and we find that the experiment with fixed surface temperature and changes in CO2 is of great relevance to understanding the total response. This result points to the importance of local radiative heating rate changes rather than just the net atmospheric radiative loss of energy. Although larger in magnitude, the response to changes in surface temperature is dominated by the temperature dependence of the water vapor pressure, but in both cases changes in near-surface relative humidity are very important.

  17. Changes in Atmospheric Constituents and in Radiative Forcing. Chapter 2

    International Nuclear Information System (INIS)

    This chapter updates information taken from Chapters 3 to 6 of the IPCC Working Group I Third Assessment Report. It concerns itself with trends in forcing agents and their precursors since 1750, and estimates their contribution to the radiative forcing (RF) of the climate system. Discussion of the understanding of atmospheric composition changes is limited to explaining the trends in forcing agents and their precursors. Areas where significant developments have occurred since the TAR are highlighted. The chapter draws on various assessments since the TAR, in particular the 2002 World Meteorological Organization (WMO), United Nations Environment Programme (UNEP) Scientific Assessment of Ozone Depletion (2003) and the IPCC Technology and Economic Assessment Panel (TEAP) special report on Safeguarding the Ozone Layer and the Global Climate System (2005). The chapter assesses anthropogenic greenhouse gas changes, aerosol changes and their impact on clouds, aviation-induced contrails and cirrus changes, surface albedo changes and natural solar and volcanic mechanisms. The chapter reassesses the 'radiative forcing' concept (Sections 2.2 and 2.8), presents spatial and temporal patterns of RF, and examines the radiative energy budget changes at the surface. For the long-lived greenhouse gases (carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluoro-carbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6), hereinafter collectively referred to as the LLGHGs; Section 2.3), the chapter makes use of new global measurement capabilities and combines long-term measurements from various networks to update trends through 2005. Compared to other RF agents, these trends are considerably better quantified; because of this, the chapter does not devote as much space to them as previous assessments (although the processes involved and the related budgets are further discussed in Sections 7.3 and 7

  18. ARTS, the atmospheric radiative transfer simulator, version 2

    International Nuclear Information System (INIS)

    The second version of the atmospheric radiative transfer simulator, ARTS, is introduced. This is a general software package for long wavelength radiative transfer simulations, with a focus on passive microwave observations. The core part provides a workspace environment, in line with script languages. New for this version is an agenda mechanism that gives a high degree of modularity. The framework is intended to be as general as possible: the polarisation state can be fully described, the model atmosphere can be one- (1D), two- (2D) or three-dimensional (3D), a full description of geoid and surface is possible, observation geometries from the ground, from satellite, and from aeroplane or balloon are handled, and surface reflection can be treated in simple or complex manners. Remote sensing applications are supported by a comprehensive and efficient treatment of sensor characteristics. Jacobians can be calculated for the most important atmospheric variables in non-scattering conditions. Finally, the most prominent feature is the rigorous treatment of scattering that has been implemented in two modules: a discrete ordinate iterative approach mainly used for 1D atmospheres, and a Monte Carlo approach which is the preferred algorithm for 3D atmospheres. ARTS is freely available, and maintained as an open-source project.

  19. Transport of Ionizing Radiation in Terrestrial-like Exoplanet Atmospheres

    CERN Document Server

    Smith, D S; Wheeler, J C; Smith, David S.; Scalo, John

    2003-01-01

    (Abridged) Propagation of ionizing radiation, as from parent star flares, supernovae, or gamma-ray bursts, is studied for a suite of simple model atmospheres of terrestrial-like exoplanets covering a large range of column densities and incident photon energies. We developed a Monte Carlo code to treat the Compton scattering and photoabsorption. Atmospheres thinner than about 100 g cm^-2 transmit a significant fraction of incident gamma-rays, but even the thinnest atmospheres are essentially opaque to X-rays below about 30 keV. For thicker atmospheres, the incident ionizing radiation is efficiently blocked, but most of the incident energy is redistributed via secondary electron excitation into diffuse UV and visible aurora-like emission, increasing the atmospheric transmission by many orders of magnitude; in some cases the transmission can be up to 10%, depending on the intervening UV opacity. For Earth, between 2 x 10^-3 and 4 x 10^-2 of the incident flux reaches the ground in the 200-320 nm range, depending ...

  20. Atmospheric transport, clouds and the Arctic longwave radiation paradox

    Science.gov (United States)

    Sedlar, Joseph

    2016-04-01

    Clouds interact with radiation, causing variations in the amount of electromagnetic energy reaching the Earth's surface, or escaping the climate system to space. While globally clouds lead to an overall cooling radiative effect at the surface, over the Arctic, where annual cloud fractions are high, the surface cloud radiative effect generally results in a warming. The additional energy input from absorption and re-emission of longwave radiation by the clouds to the surface can have a profound effect on the sea ice state. Anomalous atmospheric transport of heat and moisture into the Arctic, promoting cloud formation and enhancing surface longwave radiation anomalies, has been identified as an important mechanism in preconditioning Arctic sea ice for melt. Longwave radiation is emitted equally in all directions, and changes in the atmospheric infrared emission temperature and emissivity associated with advection of heat and moisture over the Arctic should correspondingly lead to an anomalous signal in longwave radiation at the top of the atmosphere (TOA). To examine the role of atmospheric heat and moisture transport into the Arctic on TOA longwave radiation, infrared satellite sounder observations from AIRS during 2003-2014 are analyzed for summer (JJAS). Thermodynamic metrics are developed to identify months characterized by a high frequency of warm and moist advection into the Arctic, and segregate the 2003-14 time period into climatological and anomalously warm, moist summer months. We find that anomalously warm, moist months result in a significant TOA longwave radiative cooling, which is opposite the forcing signal that the surface experiences during these months. At the timescale of the advective events, 3-10 days, the TOA cooling can be as large as the net surface energy budget during summer. When averaged on the monthly time scale, and over the full Arctic basin (poleward of 75°N), summer months experiencing frequent warm, moist advection events are

  1. Atmospheric radiative transfer generalised for use on Earth and other planets: ARTS 2.2

    Science.gov (United States)

    Mendrok, Jana; Eriksson, Patrick; Buehler, Stefan; Perrin, Agnes; Hartogh, Paul; Rezac, Ladislav; Lemke, Oliver

    2015-04-01

    Microwave and (sub)millimetre-wave frequencies have long been of interest for remote sensing of the Earth and space objects. They suffer less from interference by small particles (dust, clouds), hence penetrate deeper into atmospheres revealing their deeper structures hidden to shorter wavelengths, and possess characteristic line absorption features of many gaseous species, which are of interest for the understanding of atmospheric chemistry and dynamics. Models simulating radiative transfer and wave propagation (RT/WP) have been developed by many institutions. Most of them are designed for a particular, narrow region of the electromagnetic spectrum, certain instrument types or missions, and specific atmospheric conditions. In particular, they are usually set up for a specific planetary body. This high level of specialisation allows for accurate modelling results. However, it also limits the flexibility of those models and comparability between them. One of the major differences in radiative transfer modeling in the atmospheres of Earth and other planets arises from the different composition of the atmospheres. When interested in measuring total abundance or even vertical distribution of atmospheric constituents, knowledge of parameters describing spectrally dependent absorption in dependence of atmospheric state is required. When modeling radiative transfer for different planets, the line shapes are often accounted for by scaling the parameters valid for Earth's ``air'' or by building a spectroscopic catalogue specific to the planet in question and its main atmospheric composition. This strongly limits applicability of these models. Based on the ARTS model [1], a sophisticated, flexible RT model for Earth atmosphere (3D spherical geometry, diverse absorption models, scattering, polarization, Jacobians), we have developed a toolbox for microwave atmospheric radiative transfer in solar system planets. As part of this, we developed and implemented a more generalized

  2. Radiative heating and cooling in the middle and lower atmosphere of Venus and responses to atmospheric and spectroscopic parameter variations

    Science.gov (United States)

    Haus, R.; Kappel, D.; Arnold, G.

    2015-11-01

    A sophisticated radiative transfer model that considers absorption, emission, and multiple scattering by gaseous and particulate constituents over the broad spectral range 0.125-1000 μm is applied to calculate radiative fluxes and temperature change rates in the middle and lower atmosphere of Venus (0-100 km). Responses of these quantities to spectroscopic and atmospheric parameter variations are examined in great detail. Spectroscopic parameter studies include the definition of an optimum spectral grid for monochromatic calculations as well as comparisons for different input data with respect to spectral line databases, continuum absorption, line shape factors, and solar irradiance spectra. Atmospheric parameter studies are based on distinct variations of an initial model data set. Analyses of actual variations of the radiative energy budget using atmospheric features that have been recently retrieved from Venus Express data will be subject of a subsequent paper. The calculated cooling (heating) rates are very reliable at altitudes below 95 (85) km with maximum uncertainties of about 0.25 K/day. Heating uncertainties may reach 3-5 K/day at 100 km. Using equivalent Planck radiation as solar insolation source in place of measured spectra is not recommended. Cooling rates strongly respond to variations of atmospheric thermal structure, while heating rates are less sensitive. The influence of mesospheric minor gas variations is small, but may become more important near the cloud base and in case of episodic SO2 boosts. Responses to cloud mode 1 particle abundance changes are weak, but variations of other mode parameters (abundances, cloud top and base altitudes) may significantly alter radiative temperature change rates up to 50% in Venus' lower mesosphere and upper troposphere. A new model for the unknown UV absorber for two altitude domains is proposed. It is not directly linked to cloud particle modes and permits an investigation of radiative effects regardless of

  3. The Dynamics of the Atmospheric Radiation Environment at Aviation Altitudes

    Science.gov (United States)

    Stassinopoulos, Epaminondas G.

    2004-01-01

    Single Event Effects vulnerability of on-board computers that regulate the: navigational, flight control, communication, and life support systems has become an issue in advanced modern aircraft, especially those that may be equipped with new technology devices in terabit memory banks (low voltage, nanometer feature size, gigabit integration). To address this concern, radiation spectrometers need to fly continually on a multitude of carriers over long periods of time so as to accumulate sufficient information that will broaden our understanding of the very dynamic and complex nature of the atmospheric radiation environment regarding: composition, spectral distribution, intensity, temporal variation, and spatial variation.

  4. Evaluation of arctic broadband surface radiation measurements

    OpenAIRE

    Matsui, N.; C. N. Long; J. Augustine; Halliwell, D.; T. Uttal; Longenecker, D.; O. Nievergall; Wendell, J.; Albee, R.

    2011-01-01

    The Arctic is a challenging environment for making in-situ radiation measurements. A standard suite of radiation sensors is typically designed to measure the total, direct and diffuse components of incoming and outgoing broadband shortwave (SW) and broadband thermal infrared, or longwave (LW) radiation. Enhancements can include various sensors for measuring irradiance in various narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are...

  5. Evaluation of Arctic broadband surface radiation measurements

    OpenAIRE

    Matsui, N.; C. N. Long; J. Augustine; Halliwell, D.; T. Uttal; Longenecker, D.; Niebergall, O.; Wendell, J.; Albee, R.

    2012-01-01

    The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW) and thermal infrared, or longwave (LW), radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers) that ...

  6. SUMER: Solar Ultraviolet Measurements of Emitted Radiation

    Science.gov (United States)

    Wilhelm, K.; Axford, W. I.; Curdt, W.; Gabriel, A. H.; Grewing, M.; Huber, M. C. E.; Jordan, M. C. E.; Lemaire, P.; Marsch, E.; Poland, A. I.

    1988-01-01

    The SUMER (solar ultraviolet measurements of emitted radiation) experiment is described. It will study flows, turbulent motions, waves, temperatures and densities of the plasma in the upper atmosphere of the Sun. Structures and events associated with solar magnetic activity will be observed on various spatial and temporal scales. This will contribute to the understanding of coronal heating processes and the solar wind expansion. The instrument will take images of the Sun in EUV (extreme ultra violet) light with high resolution in space, wavelength and time. The spatial resolution and spectral resolving power of the instrument are described. Spectral shifts can be determined with subpixel accuracy. The wavelength range extends from 500 to 1600 angstroms. The integration time can be as short as one second. Line profiles, shifts and broadenings are studied. Ratios of temperature and density sensitive EUV emission lines are established.

  7. A review of worldwide atmospheric mercury measurements

    Directory of Open Access Journals (Sweden)

    F. Sprovieri

    2010-09-01

    Full Text Available A large number of activities have been carried out to characterise the levels of mercury (Hg species in ambient air and precipitation, in order to understand how they vary over time and how they depend on meteorological conditions. Following the discovery of atmospheric Hg depletion events (AMDEs in Polar Regions, a significant research effort was made to assess the chemical-physical mechanisms behind the rapid conversion of atmospheric gaseous Hg (Hg0 into reactive and water-soluble forms which are potentially bioavailable. The understanding of the way in which Hg is released into the atmosphere, transformed, deposited and eventually incorporated into biota is of crucial importance not only for the polar regions but also for the marine environment in general. The oceans and seas are both sources and sinks of Hg and play a major role in the Hg cycle. In this work, the available Hg concentration datasets from a number of terrestrial sites (industrial, rural and remote in both the Northern and Southern Hemispheres as well as over oceans and seas have been investigated. The higher Hg species concentration and variability observed in the Northern Hemisphere suggest that the majority of emissions and re-emissions occur there. The inter-hemispherical gradient with higher total gaseous mercury (TGM concentrations in the Northern Hemisphere has remained nearly constant over the years for which data are available. The analysis of Hg concentration patterns indicates the differences in regional source/sink characteristics, with increasing variability toward areas strongly influenced by anthropogenic sources. The large increase in Hg emissions in rapidly developing countries (i.e., China, India over the last decade, due primarily to a sharp increase in energy production from coal combustion, are not currently reflected in the long-term measurements of TGM in ambient air and precipitation at continuous monitoring sites in either Northern Europe or

  8. Atmospheric pressure photoionization using tunable VUV synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, A., E-mail: alexandre.giuliani@synchrotron-soleil.fr [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette (France); INRA, U1008 CEPIA, Rue de la Geraudiere, F-44316 Nantes (France); Giorgetta, J.-L.; Ricaud, J.-P. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette (France); Jamme, F. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette (France); INRA, U1008 CEPIA, Rue de la Geraudiere, F-44316 Nantes (France); Rouam, V.; Wien, F. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette (France); Laprevote, O. [Laboratoire de Spectrometrie de Masse, ICSN-CNRS, 1 Avenue de la Terrasse, 91190 Gif-sur-Yvette (France); Laboratoire de Chimie-Toxicologie Analytique et cellulaire, IFR 71, Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, 4 Avenue de l' Observatoire, 75006 Paris (France); Refregiers, M. [Synchrotron SOLEIL, L' Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette (France)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Coupling of an atmospheric pressure photoionization source with a vacuum ultra-violet (VUV) beamline. Black-Right-Pointing-Pointer The set up allows photoionization up to 20 eV. Black-Right-Pointing-Pointer Compared to classical atmospheric pressure photoionization (APPI), our set up offers spectral purity and tunability. Black-Right-Pointing-Pointer Allows photoionization mass spectrometry on fragile and hard to vaporize molecules. - Abstract: We report here the first coupling of an atmospheric pressure photoionization (APPI) source with a synchrotron radiation beamline in the vacuum ultra-violet (VUV). A commercial APPI source of a QStar Pulsar i from AB Sciex was modified to receive photons from the DISCO beamline at the SOLEIL synchrotron radiation facility. Photons are delivered at atmospheric pressure in the 4-20 eV range. The advantages of this new set up, termed SR-APPI, over classical APPI are spectral purity and continuous tunability. The technique may also be used to perform tunable photoionization mass spectrometry on fragile compounds difficult to vaporize by classical methods.

  9. Atmospheric scattering and decay of inner radiation belt electrons

    Science.gov (United States)

    Selesnick, R. S.

    2012-08-01

    The dynamics of inner radiation belt electrons are governed by competing source, loss, and transport processes. However, during the recent extended solar minimum period the source was inactive and electron intensity was characterized by steady decay. This provided an opportunity to determine contributions to the decay rate of losses by precipitation into the atmosphere and of diffusive radial transport. To this end, a stochastic simulation of inner radiation belt electron transport is compared to data taken by the IDP instrument on the DEMETER satellite during 2009. For quasi-trapped, 200 keV electrons atL= 1.3, observed in the drift loss cone (DLC), results are consistent with electron precipitation losses by atmospheric scattering alone, provided account is taken of non-diffusive wide-angle scattering. Such scattering is included in the stochastic simulation using a Markov jump process. Diffusive small-angle atmospheric scattering, while causing most of the precipitation losses, is too slow relative to azimuthal drift to contribute significantly to DLC intensity. Similarly there is no contribution from scattering by VLF plasma waves. Energy loss, energy diffusion, and azimuthal drift are also included in the model. Even so, observed decay rates of stably-trapped electrons withL diffusion with coefficient DLL ˜ 3 × 10-10 s-1 to replenish electrons lost to the atmosphere at low L values.

  10. Ambient radiation exposure: measurements and effects

    International Nuclear Information System (INIS)

    A brief review of the available literature, data and reports of various radiation exposure and protection studies and various measurements techniques are presented. A linear quadratic model has been given illustrating the validity of radiation hormesis

  11. Environmental radiation measurement in CTBT verification system

    International Nuclear Information System (INIS)

    well as the development of the automatic analyzing system of gamma-ray spectrum data and the atmospheric diffusion backtracking software, both of which are necessary for the NDC 2. Technologies, data, and samples obtained through the CTBT activities are supposed to be provided for the interest of the signatory nations. Equally high-quality measurement data and filter samples from the stations around the world offer opportunities, on a global scale, for detecting radionuclide dispersion, monitoring radiation levels and studying natural radioactivity, as well as supporting atmospheric studies, biological research and environmental change tracking. (author)

  12. Processing of atmospheric organic matter by California radiation fogs

    Science.gov (United States)

    Collett, Jeffrey L., Jr.; Herckes, Pierre; Youngster, Sarah; Lee, Taehyoung

    2008-03-01

    Considerable effort has been put into characterizing the ionic composition of fogs and clouds over the past twenty-five years. Recently it has become evident that clouds and fogs often contain large concentrations of organic material as well. Here we report findings from a series of studies examining the organic composition of radiation fogs in central California. Organic compounds in these fogs comprise a major fraction of total solute mass, with total organic carbon sometimes reaching levels of several tens of mg/L. This organic matter is comprised of a wide variety of compounds, ranging from low molecular weight organic acids to high molecular weight compounds with molecular masses approaching several hundred to a thousand g/mole. The most abundant individual compounds are typically formic acid, acetic acid, and formaldehyde. High concentrations are also observed of some dicarboxylic acids (e.g., oxalate) and dicarbonyls (e.g., glyoxal and methylglyoxal) and of levoglucosan, an anhydrosugar characteristically emitted by biomass combustion. Many other compounds have been identified in fog water by GC/MS, including long chain n-alkanoic acids, n-alkanes, PAH, and others, although these compounds typically comprise a total of only a few percent of fog TOC. Measurements of fog scavenging of organic and elemental carbon reveal preferential scavenging of organic carbon. Tracking of individual organic compounds utilized as source type markers suggests the fogs differentially scavenge carbonaceous particles from different source types, with more active processing of wood smoke than vehicle exhaust. Observations of high deposition velocities of fog-borne organic carbon, in excess of 1 cm/s, indicate that fogs in the region represent an important mechanism for cleansing the atmosphere of pollution.

  13. Atmospheric effect on the ground-based measurements of broadband surface albedo

    OpenAIRE

    Manninen, T.; Riihelä, A.; De Leeuw, G.

    2012-01-01

    Ground-based pyranometer measurements of the (clear-sky) broadband surface albedo are affected by the atmospheric conditions (mainly by aerosol particles, water vapour and ozone). A new semi-empirical method for estimating the magnitude of the effect of atmospheric conditions on surface albedo measurements in clear-sky conditions is presented. Global and reflected radiation and/or aerosol optical depth (AOD) at two wavelengths are needed to apply the method. Depending on the...

  14. Long-path atmospheric measurements using dual frequency comb measurements

    Science.gov (United States)

    Waxman, Eleanor; Cossel, Kevin; Truong, Gar-Wing; Giorgetta, Fabrizio; Swann, William; Coddington, Ian; Newbury, Nathan

    2016-04-01

    The dual frequency comb spectrometer is a new tool for performing atmospheric trace gas measurements. This instrument is capable of measuring carbon dioxide, methane, and water with extremely high resolution in the region between 1.5 and 2.1 microns in the near-IR. It combines the high resolution of a laboratory-based FTIR instrument with the portability of a long-path DOAS system. We operate this instrument at path lengths of a few kilometers, thus bridging the spatial resolution of in-situ point sensors and the tens of square kilometer footprints of satellites. This spatial resolution is ideal for measuring greenhouse gas emissions from cities. Here we present initial long-path integrated column measurements of the greenhouse gases water, carbon dioxide, and methane in an urban environment. We present a time series with 5 minute time resolution over a 2 kilometer path in Boulder, Colorado at the urban-rural interface. We validate this data via a comparison with an in-situ greenhouse gas monitor co-located along the measurement path and show that we agree well on the baseline concentration but that we are significantly less sensitive to local point source emission that have high temporal variability, making this instrument ideal for measurements of average city-wide emissions. We additionally present progress towards measurements over an 11 kilometer path over downtown Boulder to measure the diurnal flux of greenhouse gases across the city.

  15. Measurement of Atmospheric Composition from Geostationary Platforms

    Science.gov (United States)

    Bhartia, P. K.; Kawa, S. R.; Janz, S.; Herman, J. R.; Gleason, J. F.

    2008-01-01

    Satellite instruments flown since 1970 have had great success in elucidating the processes that control stratospheric ozone. In contrast, space-based data for tropospheric constituents that affect air quality and climate have only recently become available. While these datasets highlight the rapidly advancing capabilities of spacebased tropospheric sensors, they are also pointing to the limitations of sun-synchronous, low-earth orbiting (SSO/LEO) satellite platforms for making such measurements. In our talk we will highlight the science requirements for new missions and the technological and algorithmic approaches that we are developing to meet these requirements. From these studies a clear need for advanced atmospheric composition sensors has emerged that can be put on geostationary (GEO) platforms to provide 5 km horizontal resolution with 15-60 minutes repeat cycle. Such measurements have been high priority in the recently released Decadal Survey report by the US National Research Council. The need for GEO is driven not only by the science requirements to track rapidly changing pollution events but also by the need to provide altitude-resolved information about tropospheric constituents. Currently, with the exception of aerosols, it is not possible to derive profile information about lower tropospheric constituents from satellite measurements. New algorithmic approaches are being developed to obtain this information by combining UV and IR data, by monitoring the spatial and temporal structures of the constituents, and by using low-level clouds to separate boundary layer constituents from free troposphere. All these approaches require better spatial and temporal resolution than that provided by LEO sensors.

  16. Measuring NIR Atmospheric Extinction Using a Global Positioning System Receiver

    CERN Document Server

    Blake, Cullen H

    2011-01-01

    Modeling molecular absorption by Earth's atmosphere is important for a wide range of astronomical observations, including broadband NIR photometry and high-resolution NIR spectroscopy. Using a line-by-line radiative transfer approach, we calculate theoretical transmission spectra in the deep red optical (700 to 1050 nm) for Apache Point Observatory. In this region the spectrum is dominated by H2O, which is known to be highly variable in concentration on short timescales. We fit our telluric models to high-resolution observations of A stars and estimate the relative optical depth of H2O absorption under a wide range of observing conditions. We compare these optical depth estimates to simultaneous measurements of Precipitable Water Vapor (PWV) based on data from a Global Positioning System (GPS) receiver located at Apache Point. We find that measured PWV correlates strongly with the scaling of H2O absorption lines in our spectra, indicating that GPS-based PWV measurements combined with atmospheric models may be...

  17. Measurement of radiation damage on silica aerogel Cerenkov radiator

    CERN Document Server

    Sahu, S K; Suda, R; Enomoto, R; Peng, K C; Wang, C H; Adachi, I; Amami, M; Chang, Y H; Guo, R S; Hayashi, K; Iijima, T; Sumiyoshi, T; Yoshida, Y

    1996-01-01

    We measured the radiation damage on silica aerogel \\v Cerenkov radiators originally developed for the B-factory experiment at KEK. Refractive index of the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up to 9.8~MRad of equivalent dose. Measurements of transmittance and refractive index were carried out and these samples were found to be radiation hard. Deteriorations in transparency and changes of refractive index were observed to be less than 1.3\\% and 0.001 at 90\\% confidence level, respectively. Prospects of using aerogels under high-radiation environment are discussed.

  18. Measurement of radiation damage on a silica aerogel Cherenkov radiator

    International Nuclear Information System (INIS)

    We measured the radiation damage on silica aerogel Cherenkov radiators originally developed for the B-factory experiment at KEK. The refractive index of the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up to 9.8 Mrad of equivalent dose. Measurements of transmittance and refractive index were carried out and these samples were found to be radiation hard. Deteriorations in transparency and changes of refractive index were observed to be less than 1.3% and 0.001 at 90% confidence level, respectively. Prospects of using aerogels under high-radiation environment are discussed. (orig.)

  19. A single-scattering approximation for infrared radiative transfer in limb geometry in the Martian atmosphere

    International Nuclear Information System (INIS)

    We present a single-scattering approximation for infrared radiative transfer in limb geometry in the Martian atmosphere. It is based on the assumption that the upwelling internal radiation field is dominated by a surface with a uniform brightness temperature. It allows the calculation of the scattering source function for individual aerosol types, mixtures of aerosol types, and mixtures of gas and aerosol. The approximation can be applied in a Curtis-Godson radiative transfer code and is used for operational retrievals from Mars Climate Sounder measurements. Radiance comparisons with a multiple scattering model show good agreement in the mid- and far-infrared although the approximate model tends to underestimate the radiances in realistic conditions of the Martian atmosphere. Relative radiance differences are found to be about 2% in the lowermost atmosphere, increasing to ∼10% in the middle atmosphere of Mars. The increasing differences with altitude are mostly due to the increasing contribution to limb radiance of scattering relative to emission at the colder, higher atmospheric levels. This effect becomes smaller toward longer wavelengths at typical Martian temperatures. The relative radiance differences are expected to produce systematic errors of similar magnitude in retrieved opacity profiles.

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

    International Nuclear Information System (INIS)

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

  1. Relations between radiation risks and radiation protection measuring techniques

    International Nuclear Information System (INIS)

    Relations between radiation risks and radiation protection measuring techniques are considered as components of the radiation risk. The influence of the exposure risk on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Based upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high exposure risk. As a consequence the following recommendations are presented: occupationally exposed persons with small exposure risk should be monitored using only a long-term desimeter (for instance a thermoluminescence desimeter). In the case of internal exposure, the surface and air contamination levels should be controlled so strictly that routine measurements of internal contamination need not be performed

  2. Experimental Characterization of Radiation Forcing due to Atmospheric Aerosols

    Science.gov (United States)

    Sreenivas, K. R.; Singh, D. K.; Ponnulakshmi, V. K.; Subramanian, G.

    2011-11-01

    Micro-meteorological processes in the nocturnal atmospheric boundary layer (NBL) including the formation of radiation-fog and the development of inversion layers are controlled by heat transfer and the vertical temperature distribution close to the ground. In a recent study, it has been shown that the temperature profile close to the ground in stably-stratified, NBL is controlled by the radiative forcing due to suspended aerosols. Estimating aerosol forcing is also important in geo-engineering applications to evaluate the use of aerosols to mitigate greenhouse effects. Modeling capability in the above scenarios is limited by our knowledge of this forcing. Here, the design of an experimental setup is presented which can be used for evaluating the IR-radiation forcing on aerosols under either Rayleigh-Benard condition or under conditions corresponding to the NBL. We present results indicating the effect of surface emissivities of the top and bottom boundaries and the aerosol concentration on the temperature profiles. In order to understand the observed enhancement of the convection-threshold, we have determined the conduction-radiation time constant of an aerosol laden air layer. Our results help to explain observed temperature profiles in the NBL, the apparent stability of such profiles and indicate the need to account for the effect of aerosols in climatic/weather models.

  3. Next-generation angular distribution models for top-of-atmosphere radiative flux calculation from CERES instruments: methodology

    OpenAIRE

    W. Su; Corbett, J; Z. Eitzen; L. Liang

    2015-01-01

    The top-of-atmosphere (TOA) radiative fluxes are critical components to advancing our understanding of the Earth's radiative energy balance, radiative effects of clouds and aerosols, and climate feedback. The Clouds and the Earth's Radiant Energy System (CERES) instruments provide broadband shortwave and longwave radiance measurements. These radiances are converted to fluxes by using scene-type-dependent angular distribution models (ADMs). This paper describes the next-gener...

  4. Magellan radio occultation measurements of atmospheric waves on Venus

    Science.gov (United States)

    Hinson, David P.; Jenkins, J. M.

    1995-01-01

    Radio occultation experiments were conducted at Venus on three consecutive orbits of the Magellan spacecraft in October 1991. Each occultation occurred over the same topography (67 deg N, 127 deg E) and at the same local time (22 hr 5 min), but the data are sensitive to zonal variations because the atmosphere rotates significantly during one orbit. Through comparisons between observations and predictions of standard wave theory, we have demonstrated that small-scale oscillations in retrieved temperature profiles as well as scintillations in received signal intensity are caused by a spectrum of vertically propagating internal gravity waves. There is a strong similarity between the intensity scintillations observed here and previous measurements, which pertain to a wide range of locations and experiment dates. This implies that the same basic phenomenon underlies all the observations and hence that gravity waves are a persistent, global feature of Venus' atmosphere. We obtained a fairly complete characterization of a gravity wave that appears above the middle cloud in temperature measurements on all three orbits. The amplitude and vertical wavelength are about 4 K and 2.5 km respectively, at 65 km. A model for radiative damping implies that the wave intrinsic frequency is approximately 2 x 10(exp 4) rad/sec, the corresponding ratio between horizontal and vertical wavelengths is approximately 100. The wave is nearly stationary relative to the surface or the Sun. Radiative attenuation limits the wave amplitude at altitudes above approximately 65 km, leading to wave drag on the mean zonal winds of about +0.4 m/sec per day (eastward). The sign, magnitude, and location of this forcing suggest a possible role in explaining the decrease with height in the zonal wind speed that is believed to occur above the cloud tops. Temperature oscillations with larger vertical wavelengths (5-10 km) were also observed on all three orbits, but we are able unable to interpret these

  5. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2013-04-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  6. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2012-12-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  7. Airborne Measurements of Atmospheric Methane Using Pulsed Laser Transmitters

    Science.gov (United States)

    Numata, Kenji; Riris, Haris; Wu, Stewart; Gonzalez, Brayler; Rodriguez, Michael; Hasselbrack, William; Fahey, Molly; Yu, Anthony; Stephen, Mark; Mao, Jianping; Kawa, Stephan

    2016-01-01

    Atmospheric methane (CH4) is the second most important anthropogenic greenhouse gas with approximately 25 times the radiative forcing of carbon dioxide (CO2) per molecule. At NASA Goddard Space Flight Center (GSFC) we have been developing a laser-based technology needed to remotely measure CH4 from orbit. We report on our development effort for the methane lidar, especially on our laser transmitters and recent airborne demonstration. Our lidar transmitter is based on an optical parametric process to generate near infrared laser radiation at 1651 nanometers, coincident with a CH4 absorption. In an airborne flight campaign in the fall of 2015, we tested two kinds of laser transmitters --- an optical parametric amplifier (OPA) and an optical parametric oscillator (OPO). The output wavelength of the lasers was rapidly tuned over the CH4 absorption by tuning the seed laser to sample the CH4 absorption line at several wavelengths. This approach uses the same Integrated Path Differential Absorption (IPDA) technique we have used for our CO2 lidar for ASCENDS. The two laser transmitters were successfully operated in the NASAs DC-8 aircraft, measuring methane from 3 to 13 kilometers with high precision.

  8. Radiative instabilities of atmospheric jets and boundary layers

    International Nuclear Information System (INIS)

    Complex flows occur in the atmosphere and they can be source of internal gravity waves. We focus here on the sources associated with radiative and shear (or Kelvin-Helmholtz) instabilities. Stability studies of shear layers in a stably stratified fluid concern mainly cases where shear and stratification are aligned along the same direction. In these cases, Miles (1961) and Howard (1961) found a necessary condition for stability based on the Richardson number: Ri ≥ 1/4. In this thesis, we show that this condition is not necessary when shear and stratification are not aligned: we demonstrate that a two-dimensional planar Bickley jet can be unstable for all Richardson numbers. Although the most unstable mode remains 2D, we show there exists an infinite family of 3D unstable modes exhibiting a radiative structure. A WKBJ theory is found to provide the main characteristics of these modes. We also study an inviscid and stratified boundary layer over an inclined wall with non-Boussinesq and compressible effects. We show that this flow is unstable as soon as the wall is not horizontal for all Froude numbers and that strongly stratified 3D perturbations behave exactly like compressible 2D perturbations. Applications of the results to the jet stream and the atmospheric boundary layer are proposed. (author)

  9. Analytical properties of the radiance in atmospheric radiative transfer theory

    International Nuclear Information System (INIS)

    It is demonstrated mathematically strictly that state density functions, as the radiance (specific intensity), exist to describe certain state properties of transported photons on microscopic and the state of the radiation field on macroscopic scale, which have independent physical meanings. Analytical properties as boundedness, continuity, differentiability and integrability of these functions to describe the photon transport are discussed. It is shown that the density functions may be derived based on the assumption of photons as real particles of non-zero and finite size, independently of usual electrodynamics, and certain historically postulated functional relationships between them were proved, that is, these functions can be derived mathematically strictly and consistently within the framework of the theory of the phenomenological radiative transfer if one takes the theory seriously by really assuming photons as particles. In this sense these functions may be treated as fundamental physical quantities within the scope of this theory, if one considers the possibility of the existence of photons. -- Highlights: • Proof of existence of the radiance within the scope of the theory of atmospheric radiative transfer. • Proof of relations between the photon number and photon energy density function and the radiance. • Strictly mathematical derivation of the analytical properties of these state density functions

  10. Radiative transfer modeling in the coupled atmosphere- ocean system and its application to the remote sensing of ocean color imagery

    Science.gov (United States)

    Yan, Banghua

    2001-12-01

    Ocean color is the radiance emanating from the ocean due to scattering by chlorophyll pigments and particles of organic and inorganic origin. Thus, it contains information about chlorophyll concentrations which can be used to estimate primary productivity. Observations of ocean color from space can be used to monitor the variability in marine primary productivity, thereby permitting a quantum leap in our understanding of oceanographic processes from regional to global scales. Satellite remote sensing of ocean color requires accurate removal of the contribution by atmospheric molecules and aerosols to the radiance measured at the top of the atmosphere (TOA). This removal process is called ``atmospheric correction''. Since about 90% of the radiance received by the satellite sensor comes from the atmosphere, accurate removal of this portion is very important. A prerequisite for accurate atmospheric correction is accurate and reliable simulation of the transport of radiation in the atmosphere-ocean system. This thesis focuses on this radiative transfer process, and investigates the impact of particles in the atmosphere (aerosols) and ocean (oceanic chlorophylls and air bubbles) on our ability to remove the atmospheric contribution from the received signal. To explore these issues, a comprehensive radiative transfer model for the coupled atmosphere-ocean system is used to simulate the radiative transfer process and provide a physically sound link between surface-based measurements of oceanic and atmospheric parameters and radiances observed by satellite-deployed ocean color sensors. This model has been upgraded to provide accurate radiances in arbitrary directions as required to analyze satellite data. The model is then applied to quantify the uncertainties associated with several commonly made assumptions invoked in atmospheric correction algorithms. Since atmospheric aerosols consist of a mixture of absorbing and non- absorbing components that may or may not be

  11. Longwave atmospheric radiation as a possible indicator of the aviation impact

    Energy Technology Data Exchange (ETDEWEB)

    Zaitseva, N.A. [Central Aerological Observatory of the Russian Federal Service for Hydrometeorology and Environmental Monitoring, Moscow (Russian Federation)

    1997-12-31

    Aircraft emissions changing composition of the atmospheric air should be sensed by radiation parameters, such as downward (in first turn) and upward long-wave fluxes. It might be supposed that the accurate measurements of long-wave (LW) radiation fluxes in regions of crowded aircraft routes time outside these regions, could detect the influence. Main transformation of the long-wave radiation (LWR) proceeds in the troposphere which absorbs and irradiates the LWR. The only mass method of the LWR measurements in the free atmosphere became the radiometer probe. In the former USSR it was successfully developed in 1961, and since 1963 the special radiometer sounding network started to make regular observations over the USSR territory. Rather small spatial variations of the downward LWR flux was observed indicating rather high homogeneity of the atmosphere composition. Analysis of the seasonal variations of the downward LWR has revealed that over some stations it has the opposite course of changes from summer to winter and it is mainly observed at rather high levels. (R.P.) 10 refs.

  12. Measurement of the concentration ratio for 13N and 12N isotopes at atmospheric pressure by carbon dioxide absorption of diode laser radiation at ∼2 μm

    International Nuclear Information System (INIS)

    The ratio of 12NO2 and 13CO2 concentrations in the human exhaled air is measured by the method of diode laser spectroscopy using a three-channel optical scheme and multipass cell. Unlike the previous measurements in the spectral range of ∼4.3 μm with a resolved rotational structure at low pressure of selected samples, the present measurements are performed in the range of ∼2 μm, in which weaker absorption bands of CO2 reside. In this case, it is possible to employ lasers and photodetectors operating at room temperature. The thorough simulation of the spectrum with collisional broadening of lines and employment of regression analysis allow one to take measurements at atmospheric pressure with the accuracy of ∼0.04%, which satisfies the requirements to medical diagnostics of ulcers. (laser spectroscopy)

  13. The Nature of the Radiative Hydrodynamic Instabilities in Radiatively Supported Thomson Atmospheres

    CERN Document Server

    Shaviv, N J

    2001-01-01

    Atmospheres having a significant radiative support are shown to be intrinsically unstable at luminosities above a critical fraction Gamma_crit ~ 0.5-0.85 of the Eddington limit, with the exact value depending on the boundary conditions. Two different types of absolute radiation-hydrodynamic instabilities of acoustic waves are found to take place even in the electron scattering dominated limit. Both instabilities grow over dynamical time scales and both operate on non radial modes. One is stationary and arises only after the effects of the boundary conditions are taken into account, while the second is a propagating wave and is insensitive to the boundary conditions. Although a significant wind can be generated by these instabilities even below the classical Eddington luminosity limit, quasi-stable configurations can exist beyond the Eddington limit due to the generally reduced effective opacity. The study is done using a rigorous numerical linear analysis of a gray plane parallel atmosphere under the Eddingto...

  14. Measuring transient radiation effects in optical fibers

    International Nuclear Information System (INIS)

    We propose a new method for measuring transient radiation effects in optical fibers on a nanosecond timescale. The method, which incorporates a streak camera, allows more precise time resolution than other methods and has the advantage of measuring the radiation-induced attenuation as a function of wavelength and time simultaneously. By choosing different light sources and sweep speeds, radiation-induced attenuation may be measured under a variety of experimental configurations. Examples of the type of output obtained with our method are given

  15. Radiation doses from Hanford site releases to the atmosphere

    International Nuclear Information System (INIS)

    Radiation doses to individuals were estimated for the years 1944-1992. The dose estimates were based on the radioactive-releases from the Hanford Site in south central Washington. Conceptual models and computer codes were used to reconstruct doses through the early 1970s. The published Hanford Site annual environmental data were used to complete the does history through 1992. The most significant exposure pathway was found to be the consumption of cow's milk containing iodine-131. For the atmospheric pathway, median cumulative dose estimates to the thyroid of children ranged from < 0.1 to 235 rad throughout the area studied. The geographic distribution of the dose levels was directly related to the pattern of iodine-131 deposition and was affected by the distribution of commercial milk and leafy vegetables. For the atmospheric pathway, the-highest estimated cumulative-effective-dose-equivalent (EDE) to an adult was estimated to be 1 rem at Ringold, Washington for the period 1944-1992. For the Columbia River pathway, cumulative EDE estimates ranged from <0.5 to l.5 rem cumulative dose to maximally exposed adults downriver from the Hanford Site for the years 1944-1992. The most significant river exposure pathway was consumption of resident fish containing phosphorus-32 and zinc-65

  16. Radiation protection: Measurement, modelling, documentation. Proceedings

    International Nuclear Information System (INIS)

    The focus of this conference is on the practical aspects of radiation protection and embraces a ''core business'' of radiation protection, namely: measuring, modeling, documentation, and all the activities and good professional practices in this context. The radiation protection experts and the radiation safety officers who contributed papers to this conference are ''practitioners'' in their fields. To round up the subject matter, there are papers dealing with legal aspects, elaborating on recent regulatory provisions and requirements, and papers dicsussing new approaches in designing and disseminating information to the public. (orig./CB)

  17. Hydraulic effects in a radiative atmosphere with ionization

    CERN Document Server

    Bhat, Pallavi

    2014-01-01

    In a paper of 1978, Eugene Parker postulated the need for hydraulic downward motion to explain magnetic flux concentrations at the solar surface. A similar process has recently also been seen in simplified (e.g., isothermal) models of flux concentrations from the negative effective magnetic pressure instability. We study the effects of partial ionization near the radiative surface on the formation of such magnetic flux concentrations. We first obtain one-dimensional (1D) equilibrium solutions using either a Kramers-like opacity or the ${\\rm H}^{-}$ opacity. The resulting atmospheres are then used as initial conditions in two-dimensional (2D) models where flows are driven by an imposed gradient force resembling a localized negative pressure in the form of a blob. To isolate the effects of partial ionization and radiation, we ignore turbulence and convection. In 1D models, due to partial ionization, an unstable stratification forms always near the surface. We show that the extrema in the specific entropy profil...

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

    Science.gov (United States)

    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.

  19. Direct measurements of nitric oxide height distribution in the middle atmosphere

    International Nuclear Information System (INIS)

    The [NO] distribution over the entire range of middle atmosphere altitudes (∼20-100 km) has been obtained in only one experiment involving measurement of solar radiation absorption in the infrared range; the measurements were performed aboard the orbital station Spacelab-1. This study presents results of the first direct rock measurements of the height distribution of nitric oxide in the range ∼30-90 km, performed by an RFI photoionization sensor

  20. The Monte Carlo atmospheric radiative transfer model McArtim: Introduction and validation of Jacobians and 3D features

    International Nuclear Information System (INIS)

    A new Monte Carlo atmospheric radiative transfer model is presented which is designed to support the interpretation of UV/vis/near-IR spectroscopic measurements of scattered Sun light in the atmosphere. The integro differential equation describing the underlying transport process and its formal solution are discussed. A stochastic approach to solve the differential equation, the Monte Carlo method, is deduced and its application to the formal solution is demonstrated. It is shown how model photon trajectories of the resulting ray tracing algorithm are used to estimate functionals of the radiation field such as radiances, actinic fluxes and light path integrals. In addition, Jacobians of the former quantities with respect to optical parameters of the atmosphere are analyzed. Model output quantities are validated against measurements, by self-consistency tests and through inter comparisons with other radiative transfer models.

  1. TEPC measurements in different radiation fields

    International Nuclear Information System (INIS)

    Some experimental results of measurements using tissue-equivalent proportional counters are given. Spectra of neutrons with different energies, gamma radiation and protons were measured. The LET spectra which constitute the test results can be used for gaining a better physical understanding and interpretation of the effects that mixed neutron-gamma radiation field would exert in the tissue. The LET spectra are also used to calibrate the detector for a wider range of particles and energies. ( M.D.)

  2. Phantoms for Radiation Measurements of Mobile Phones

    DEFF Research Database (Denmark)

    Pedersen, Gert Frølund

    2001-01-01

    Measurements of radiation efficiency for a handheld phone equipped with a patch and a helical antenna operated near the human user have been performed. Both measurements include a simple head plus hand phantom and live persons are considered. The position of the hand on the phone is found to be the...... main reason for the large variation in radiation efficiency among persons. The tilt angle of the phone and the distance between the head and phone only play a minor role...

  3. Web based Measurement System for Solar Radiation

    OpenAIRE

    Shachi Awasthi; Dr. P. Mor

    2012-01-01

    We present in this paper, the principles of the measurement system for solar radiation, and our implementation using Web based data logging concept. The photocurrent produced by Silicon PN junction is used as a solar radiation transducer, to make it more viable we have used commercially available solar panels as our transducers. Using a silicon solar cell as sensor, a low cost solar radiometer can be constructed. The photocurrent produced by solar cell is electronically tailored to be measure...

  4. MOCRA: a Monte Carlo code for the simulation of radiative transfer in the atmosphere.

    Science.gov (United States)

    Premuda, Margherita; Palazzi, Elisa; Ravegnani, Fabrizio; Bortoli, Daniele; Masieri, Samuele; Giovanelli, Giorgio

    2012-03-26

    This paper describes the radiative transfer model (RTM) MOCRA (MOnte Carlo Radiance Analysis), developed in the frame of DOAS (Differential Optical Absorption Spectroscopy) to correctly interpret remote sensing measurements of trace gas amounts in the atmosphere through the calculation of the Air Mass Factor. Besides the DOAS-related quantities, the MOCRA code yields: 1- the atmospheric transmittance in the vertical and sun directions, 2- the direct and global irradiance, 3- the single- and multiple- scattered radiance for a detector with assigned position, line of sight and field of view. Sample calculations of the main radiometric quantities calculated with MOCRA are presented and compared with the output of another RTM (MODTRAN4). A further comparison is presented between the NO2 slant column densities (SCDs) measured with DOAS at Evora (Portugal) and the ones simulated with MOCRA. Both comparisons (MOCRA-MODTRAN4 and MOCRA-observations) gave more than satisfactory results, and overall make MOCRA a versatile tool for atmospheric radiative transfer simulations and interpretation of remote sensing measurements. PMID:22453470

  5. Digital measurement of radiation using FPGA

    International Nuclear Information System (INIS)

    Recently radiation survey meters and radiation monitors which have advanced information transmission function are available for radiation safety management. They are equipped with the digital spectrometer which can identify radioactive nuclides, the global positioning system and so on. The digital-signal processing technology of a high order is necessary for the operation of these advanced instruments. Nowadays FPGA (Field Programmable Gate Array: Logical gate array that can be revised on site) is effectively used instead of ASIC (Integrated circuit for specific purpose) which needs much expense to be developed. One can flexibly build digital-signal processing circuits by using FPGA. We describe the progress of radiation measurement technology using FPGA putting emphasis on the radiation spectrum measurement technology. (J.P.N.)

  6. Ionizing radiation in industrial measurements

    International Nuclear Information System (INIS)

    The development of instruments for industrial measurements have been extensively reviewed. Especially the measuring systems for control and automation as well as industrial radiometric gages have been presented and their application in Poland and other countries have been shown. The future developing trends in the interesting branch has been discussed

  7. A Study on intelligent measurement of nuclear explosion equivalent in atmosphere

    International Nuclear Information System (INIS)

    Measurement of nuclear explosion equivalent in atmosphere is an important subject for nuclear survey. Based on the relations between nuclear explosion equivalent and the minimum illuminance time of light radiation from nuclear explosion. The method of RC differential valley time detection and mean-time taking is presented the method, using a single-chip computer as a intelligent part, can realize intelligent measurement of minimum illuminance time with high reliability and low power consumption. This method provides a practical mean for quick, accurate and reliable measurement of nuclear explosion equivalent in atmosphere

  8. Measurement of HCN in the middle atmosphere by EOS MLS

    OpenAIRE

    Pumphrey, H. C.; Jimenez, C. J.; Waters, J.W.

    2006-01-01

    The EOS MLS instrument on NASA's Aura satellite has made the first continuous global measurements of HCN in the middle atmosphere. The measurements are in broad agreement with most earlier measurements, showing HCN to be a long-lived tracer with sources in the troposphere and sinks in the middle atmosphere. There is no evidence in the data for a proposed mesospheric source of HCN.

  9. Radiation transmission pipe thickness measurement system

    International Nuclear Information System (INIS)

    Fuji Electric Systems can be measured from the outer insulation of the transmission Characteristics and radiation detection equipment had been developed that can measure pipe wall thinning in plant and running, the recruitment of another three-beam calculation method by pipe thickness measurement system was developed to measure the thickness of the pipe side. This equipment has been possible to measure the thickness of the circumferential profile of the pipe attachment by adopting automatic rotation. (author)

  10. On output measurements via radiation pressure

    DEFF Research Database (Denmark)

    Leeman, S.; Healey, A.J.; Forsberg, F.; Jensen, J.A.

    It is shown, by simple physical argument, that measurements of intensity with a radiation pressure balance should not agree with those based on calorimetric techniques. The conclusion is ultimately a consequence of the circumstance that radiation pressure measurements relate to wave momentum, while...... calorimetric methods relate to wave energy. Measurements with some typical ultrasound fields are performed with a novel type of hydrophone, and these allow an estimate to be made of the magnitude of the discrepancy to be expected between the two types of output measurement in a typical case....

  11. A horizontal mobile measuring system for atmospheric quantities

    Directory of Open Access Journals (Sweden)

    J. Hübner

    2014-05-01

    Full Text Available A fully automatic Horizontal Mobile Measuring System (HMMS for atmospheric quantities has been developed. The HMMS is based on the drive mechanism of a garden railway system and can be installed at any location and with any measuring track. In addition to meteorological quantities (temperature, humidity and short/long-wave down/upwelling radiation, HMMS also measures trace gas concentrations (carbon dioxide and ozone. While sufficient spatial resolution is a problem even for measurements on distributed towers, this could be easily achieved with the HMMS, which has been specifically developed to obtain higher information density about horizontal gradients in a heterogeneous forest ecosystem. There, horizontal gradients of meteorological quantities and trace gases could be immense, particularly at the transition from a dense forest to an open clearing, with large impact on meteorological parameters and exchange processes. Consequently, HMMS was firstly applied during EGER IOP3 project (ExchanGE processes in mountainous Regions – Intense Observation Period 3 in the Fichtelgebirge Mountains (SE Germany during summer 2011. At a constant 1 m above ground, the measuring track of the HMMS consisted of a straight line perpendicular to the forest edge, starting in the dense spruce forest and leading 75 m into an open clearing. Tags with bar codes, mounted every meter on the wooden substructure, allowed (a keeping the speed of the HMMS constant (approx. 0.5 m s−1 and (b operation of the HMMS in a continuous back and forth running mode. During EGER IOP3, HMMS was operational for almost 250 h. Results show that – due to considerably long response times (between 4 s and 20 s of commercial temperature, humidity and the radiation sensors – true spatial variations of the meteorological quantities could not be adequately captured (mainly at the forest edge. Corresponding dynamical (spatial errors of the measurement values were corrected on the basis of

  12. Exposure of Finnish population to ultraviolet radiation and radiation measurements

    International Nuclear Information System (INIS)

    This report is based on a survey of the literature on radiation risks involved in sunbathing and the use of solaria. The purpose of the report is to provide background information for the development of regulations on solaria and for informing the public about the risks posed by solaria and the sun. The report gives an overview of the properties and biological effects of ultraviolet radiation. The most important regulations and recommendations issued in various countries are presented. The connection between ultraviolet radiation and the risks of skin cancer is examined both on a general level and in reference to information obtained from the Finnish Cancer Registry. In Finland, the incidence of melanomas nearly tripled between 1960 and 1980. The most important cause is considered to be the population's increased exposure to the su's ultraviolet radiation. There are no reliable data on the connection between the use of solaria and the risks of skin cancer. It is estimated, however, that solaria account for less than 10 per cent of the skin cancer risk of the whole population. There are some difficult physical problems associated with the measurement of ultraviolet radiation emitted by both natural sources and solaria. A preliminary study of these problems has been undertaken by means of a survey of the available literature, supplemented by a review of measurements performed by the Finnish Centre For Radiation and Nuclear Safety. The estimated inaccuracy of the Optronic 742 spectroradiometer used by the Centre in the measurement of ultraviolet radiation emitted by the sun and solaria is about +-14%

  13. Laser-excited fluorescence for measuring atmospheric pollution

    Science.gov (United States)

    Menzies, R. T.

    1975-01-01

    System measures amount of given pollutant at specific location. Infrared laser aimed at location has wavelength that will cause molecules of pollutant to fluoresce. Detector separates fluorescence from other radiation and measures its intensity to indicate concentration of pollutant.

  14. Computational methods for industrial radiation measurement applications

    International Nuclear Information System (INIS)

    Computational methods have been used with considerable success to complement radiation measurements in solving a wide range of industrial problems. The almost exponential growth of computer capability and applications in the last few years leads to a open-quotes black boxclose quotes mentality for radiation measurement applications. If a black box is defined as any radiation measurement device that is capable of measuring the parameters of interest when a wide range of operating and sample conditions may occur, then the development of computational methods for industrial radiation measurement applications should now be focused on the black box approach and the deduction of properties of interest from the response with acceptable accuracy and reasonable efficiency. Nowadays, increasingly better understanding of radiation physical processes, more accurate and complete fundamental physical data, and more advanced modeling and software/hardware techniques have made it possible to make giant strides in that direction with new ideas implemented with computer software. The Center for Engineering Applications of Radioisotopes (CEAR) at North Carolina State University has been working on a variety of projects in the area of radiation analyzers and gauges for accomplishing this for quite some time, and they are discussed here with emphasis on current accomplishments

  15. Radiation distribution measurements in Fukushima prefecture

    International Nuclear Information System (INIS)

    On March 11, 2011, a huge tsunami caused by the Great East Japan Earthquake destroyed all the electrical power facilities in the Fukushima Daiichi nuclear power plant. As a result, the reactors were badly damaged, and radioactive particles were widely scattered in the surrounding areas. In order to study the behavior of the radioactive particles emitted from the Fukushima Daiichi nuclear power plant, different measurement tools were developed. This paper describes two types of wireless radiation sensor networks and a two-dimensional radiation-level mapping system using a radio-controlled multi-copter. The measurements were analyzed, and the following conclusions were made regarding the radioactive particle distribution and its variation with time. (1) Radiation level has gradually decreased with time. (2) The rate of decrease in radiation is faster than that calculated from the half-life. (3) The radiation-level distribution is not uniform and sharply varies even within short distances such as tens of meters. (4) The locations of the hot spots have not changed, and the peak radiation levels are constantly decreasing. By using two-dimensional maps, the radiation levels can be lowered more effectively by selectively removing the highly radioactive materials. The residents can also use the map to reduce their exposure to radiation by avoiding hot spots. (author)

  16. Measurements of atmospheric fallout in Argentina

    International Nuclear Information System (INIS)

    With the purpose of studying the radioactive fallout present in Argentina from atmospheric nuclear explosions tests that have been conducted recently, an environmental monitoring program, outside the influence of nuclear facilities of Argentina, was undertaken during 1996 and 1997. The levels of Cs-137 and Sr-90 were analysed in samples of air, deposited material (rainwater), milk, an average meal of a standard man and food. During this period, a total of 630 radiochemical analysis were performed on 325 samples of the different matrices described. The concentration levels of the radionuclides analysed in the different environmental matrices are presented and are compared with the values obtained in the environmental monitoring program done during the period 1960-1981. (author)

  17. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    Science.gov (United States)

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. PMID:27550757

  18. New calculations of the atmospheric cosmic radiation field - Results for neutron spectra

    International Nuclear Information System (INIS)

    The propagation of primary cosmic rays through the Earth's atmosphere and the energy spectra of the resulting secondary particles have been calculated using the Monte Carlo transport code FLUKA with several novel auxiliary methods. Solar-modulated primary cosmic ray spectra were determined through an analysis of simultaneous proton and helium measurements made on spacecraft or high-altitude balloon flights. Primary protons and helium ions are generated within the rigidity range of 0.5 GV-20 TV, uniform in cos2θ. For a given location, primaries above the effective angle-dependent geomagnetic cut-off rigidity, and re-entrant albedo protons, are transported through the atmosphere. Helium ions are initially transported using a separate transport code called HEAVY to simulate fragmentation. HEAVY interfaces with FLUKA to provide interaction starting points for each nucleon originating from a helium nucleus. Calculated cosmic ray neutron spectra and consequent dosimetric quantities for locations with a wide range of altitude (atmospheric depth) and geomagnetic cut-off are presented and compared with measurements made on a high-altitude aeroplane. Helium ion propagation using HEAVY and inclusion of re-entrant albedo protons with the incident primary spectra significantly improved the agreement of the calculated cosmic ray neutron spectra with measured spectra. These cosmic ray propagation calculations provide the basis for a new atmospheric ionising radiation (AIR) model for air-crew dosimetry, calculation of effects on microelectronics, production of cosmogenic radionuclides and other uses. (authors)

  19. Toward an Improved Understanding of the Tropical Energy Budget Using TRMM-based Atmospheric Radiative Heating Products

    Science.gov (United States)

    L'Ecuyer, T.; McGarragh, G.; Ellis, T.; Stephens, G.; Olson, W.; Grecu, M.; Shie, C.; Jiang, X.; Waliser, D.; Li, J.; Tian, B.

    2008-05-01

    It is widely recognized that clouds and precipitation exert a profound influence on the propagation of radiation through the Earth's atmosphere. In fact, feedbacks between clouds, radiation, and precipitation represent one of the most important unresolved factors inhibiting our ability to predict the consequences of global climate change. Since its launch in late 1997, the Tropical Rainfall Measuring Mission (TRMM) has collected more than a decade of rainfall measurements that now form the gold standard of satellite-based precipitation estimates. Although not as widely advertised, the instruments aboard TRMM are also well-suited to the problem of characterizing the distribution of atmospheric heating in the tropics and a series of algorithms have recently been developed for estimating profiles of radiative and latent heating from these measurements. This presentation will describe a new multi-sensor tropical radiative heating product derived primarily from TRMM observations. Extensive evaluation of the products using a combination of ground and satellite-based observations is used to place the dataset in the context of existing techniques for quantifying atmospheric radiative heating. Highlights of several recent applications of the dataset will be presented that illustrate its utility for observation-based analysis of energy and water cycle variability on seasonal to inter-annual timescales and evaluating the representation of these processes in numerical models. Emphasis will be placed on the problem of understanding the impacts of clouds and precipitation on atmospheric heating on large spatial scales, one of the primary benefits of satellite observations like those provided by TRMM.

  20. All terrain robot for remote radiation measurement

    International Nuclear Information System (INIS)

    In view of recent nuclear accidents like that in Fukushima Daiichi, the necessity for remote radiation measurement, as a first step in crisis management has been felt in the nuclear technology community. Also, some regular maintenance works in nuclear facilities result in substantial radiation exposure to human workers. All these have provided an impetus to the development of an All-Terrain Robot capable of remote radiation mapping inside nuclear installations; accordingly a prototype system has been developed at DRHR, Bhabha Atomic Research Centre. This robot has been designed to negotiate uneven terrain including staircases. Also, the robot is equipped with three onboard cameras and a retractable radiation detector and it is remotely controlled over wireless communication links with a computer. The control software, through its seamless interface, allows for easy viewing and logging of radiation data in real time. The system has been deployed and field trials have been taken

  1. New ARM Measurements of Clouds, Aerosols, and the Atmospheric State

    Science.gov (United States)

    Mather, J.

    2012-04-01

    The DOE Atmospheric Radiation Measurement (ARM) program has recently enhanced its observational capabilities at its fixed and mobile sites as well as its aerial facility. New capabilities include scanning radars, several types of lidars, an array of aerosol instruments, and in situ cloud probes. All ARM sites have been equipped with dual frequency scanning cloud radars that will provide three-dimensional observations of cloud fields for analysis of cloud field evolution. Sites in Oklahoma, Alaska, and Papua New Guinea have also received scanning centimeter wavelength radars for observing precipitation fields. This combination of radars will provide the means to study the interaction of clouds and precipitation. New lidars include a Raman lidar in Darwin, Australia and High Spectral Resolution Lidars in Barrow and with the second ARM Mobile Facility. Each of these lidars will provide profiles of aerosol extinction while the Raman will also measure profiles of water vapor. ARM has also expanded its capabilities in the realm of aerosol observations. ARM is adding Aerosol Observing Systems to its sites in Darwin and the second mobile facility. These aerosol systems principally provided measurements of aerosol optical properties. In addition, a new Mobile Aerosol Observing System has been developed that includes a variety of instruments to provide information about aerosol chemistry and size distributions. Many of these aerosol instruments are also available for the ARM Aerial Facility. The Aerial Facility also now includes a variety of cloud probes for measuring size distribution and water content. The new array of ARM instruments is intended to build upon the existing ARM capabilities to better study the interactions among aerosol, clouds, and precipitation. Data from these instruments are now available and development of advanced data products is underway.

  2. LIDAR for atmospheric backscatter and temperature measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objectives of this effort are to measure atmospheric backscatter profiles and temperature using a zenith looking lidar, designed for a small lander.The lidar...

  3. On the magnetic field signal radiated by an atmospheric pressure room temperature plasma jet

    International Nuclear Information System (INIS)

    In this paper, the magnetic field signal radiated from an atmospheric pressure room temperature plasma plume is measured. It's found that the magnetic field signal has similar waveform as the current carried by the plasma plume. By calibration of the magnetic field signal, the plasma plume current is obtained by measuring the magnetic field signal radiated by the plasma plume. In addition, it is found that, when gas flow modes changes from laminar regime to turbulence regime, the magnetic field signal waveforms appears different, it changes from a smooth curve to a curve with multiple spikes. Furthermore, it is confirmed that the plasma plume generated by a single electrode (without ground electrode) plasma jet device carries higher current than that with ground electrode.

  4. Hydraulic effects in a radiative atmosphere with ionization

    Science.gov (United States)

    Bhat, P.; Brandenburg, A.

    2016-03-01

    Context. In his 1978 paper, Eugene Parker postulated the need for hydraulic downward motion to explain magnetic flux concentrations at the solar surface. A similar process has also recently been seen in simplified (e.g., isothermal) models of flux concentrations from the negative effective magnetic pressure instability (NEMPI). Aims: We study the effects of partial ionization near the radiative surface on the formation of these magnetic flux concentrations. Methods: We first obtain one-dimensional (1D) equilibrium solutions using either a Kramers-like opacity or the H- opacity. The resulting atmospheres are then used as initial conditions in two-dimensional (2D) models where flows are driven by an imposed gradient force that resembles a localized negative pressure in the form of a blob. To isolate the effects of partial ionization and radiation, we ignore turbulence and convection. Results: Because of partial ionization, an unstable stratification always forms near the surface. We show that the extrema in the specific entropy profiles correspond to the extrema in the degree of ionization. In the 2D models without partial ionization, strong flux concentrations form just above the height where the blob is placed. Interestingly, in models with partial ionization, such flux concentrations always form at the surface well above the blob. This is due to the corresponding negative gradient in specific entropy. Owing to the absence of turbulence, the downflows reach transonic speeds. Conclusions: We demonstrate that, together with density stratification, the imposed source of negative pressure drives the formation of flux concentrations. We find that the inclusion of partial ionization affects the entropy profile dramatically, causing strong flux concentrations to form closer to the surface. We speculate that turbulence effects are needed to limit the strength of flux concentrations and homogenize the specific entropy to a stratification that is close to marginal.

  5. [Orienting endotoxin measurement in the atmosphere].

    Science.gov (United States)

    Hartung, J; Seedorf, J

    1999-12-01

    Airborne endotoxins are supposed to influence the respiratory health of animal and man in animal housings as well as at certain work places in agriculture. Little is known about the usual concentrations of endotoxin in the outdoor atmosphere. Therefore in a field study 30 air samples were taken, 22 samples in a rural region, and 8 in a more residential and industrial area. The samples were taken by impingement and filtration. The analysis was carried out by means of the chromogen-kinetic limulus amoebocyte lysate test (LAL-Test). The median concentration of all samples was 0.36 ng/m3. The highest median concentration of 0.49 ng/m3 was found in summer with a maximum value of 1.80 ng/m3 indicating large variations. In the other seasons the median concentrations (ng/m3) were distinctly lower (spring: 0.30, n = 11; autumn: 0.26, n = 5; winter: 0.19, n = 3). No significant differences were observed between farming and residential areas at this low concentration level. The concentrations of endotoxin found in this study were far below all threshold limits which are presently discussed for work places. PMID:10666935

  6. Radiation protection measurement. Philosophy and implementation

    International Nuclear Information System (INIS)

    A selection from the proceedings of the International Symposium held by the U.K. Society for radiological protection in June 1974 was presented. The central theme was the philosophy of radiation protection measurement and its interpretation although some specific areas of good health physics practice were included. The 28 papers selected were chosen to be either representative of the central theme or of wider interest. The papers have been grouped in 6 main sections: philosophy of measurements; interpretation of measurements; implementation by legislation and monitoring; radiation exposure and control; reactor safety and siting; accidents

  7. Prospects of measuring the leptonic CP phase with atmospheric neutrinos

    OpenAIRE

    Samanta, Abhijit

    2009-01-01

    We have studied the prospects of measuring the CP violating phase with atmospheric neutrinos at a large magnetized iron calorimeter detector considering the muons (directly measurable) of the neutrino events generated by a MonteCarlo event generator Nuance. The effect of $\\theta_{13}$ and $\\delta_{CP}$ appears dominantly neither in atmospheric neutrino oscillation nor in solar neutrino oscillation, but appears as subleading in both cases. These are observable in range of $E \\sim 1$ GeV for at...

  8. A radiation measurement study on cellular phone

    International Nuclear Information System (INIS)

    This paper will explain the radiation level produced by various selected cellular phone from various models and brands available in the market. The result obtained from this study will also recommend whether a cellular phone is safe for public usage or it might cause any effect on public health. Finally, a database of radiation measurement level produced by selected various cellular phone will also be developed and exhibited in this paper. (Author)

  9. A photophonic instrument concept to measure atmospheric aerosol absorption. M.S. Thesis

    Science.gov (United States)

    Engle, C. D.

    1982-01-01

    A laboratory model of an instrument to measure the absorption of atmospheric aerosols was designed, built, and tested. The design was based on the photophonic phenomenon discovered by Bell and an acoustic resonator developed by Helmholtz. Experiments were done to show ways the signal amplitude could be improved and the noise reduced and to confirm the instrument was sensitive enough to be practical. The research was undertaken to develop concepts which show promise of being improvements on the instruments that are presently used to measure the absorption of the Sun's radiation by the Earth's atmospheric aerosols.

  10. The Role of Atmospheric Measurements in Wind Power Statistical Models

    Science.gov (United States)

    Wharton, S.; Bulaevskaya, V.; Irons, Z.; Newman, J. F.; Clifton, A.

    2015-12-01

    The simplest wind power generation curves model power only as a function of the wind speed at turbine hub-height. While the latter is an essential predictor of power output, it is widely accepted that wind speed information in other parts of the vertical profile, as well as additional atmospheric variables including atmospheric stability, wind veer, and hub-height turbulence are also important factors. The goal of this work is to determine the gain in predictive ability afforded by adding additional atmospheric measurements to the power prediction model. In particular, we are interested in quantifying any gain in predictive ability afforded by measurements taken from a laser detection and ranging (lidar) instrument, as lidar provides high spatial and temporal resolution measurements of wind speed and direction at 10 or more levels throughout the rotor-disk and at heights well above. Co-located lidar and meteorological tower data as well as SCADA power data from a wind farm in Northern Oklahoma will be used to train a set of statistical models. In practice, most wind farms continue to rely on atmospheric measurements taken from less expensive, in situ instruments mounted on meteorological towers to assess turbine power response to a changing atmospheric environment. Here, we compare a large suite of atmospheric variables derived from tower measurements to those taken from lidar to determine if remote sensing devices add any competitive advantage over tower measurements alone to predict turbine power response.

  11. Humidity effects on the radiative properties of a hazy atmosphere in the visible spectrum

    OpenAIRE

    Zdunkowski, Wilford G.; Liou, Kuo-Nan

    2011-01-01

    The present investigation deals with the humidity effect on the radiative properties of a strongly polluted atmosphere in the visible spectrum. For three relative humidity distributions covering the tropospheric humidity range from 30–70%, the local albedo, the absorption and transmission of the atmosphere are obtained. Corresponding global quantities are calculated also to speculate on possible climatic effects. Additionally, radiative heating rates are calculated for the entire atmosphere, ...

  12. High-Accuracy Spectral Lines for Radiation Transport in Stellar Atmospheres

    OpenAIRE

    Amit R. Sharma; Braams, Bastiaan J.; Bowman, Joel M.; Robert Warmbier; Ralf Schneider; Hauschildt, Peter H.

    2008-01-01

    The theory of radiative transfer is an important element for the understanding of the spectral signature and physical structure of stellar atmosphere. PHOENIX1 is a such, very general non-Local Thermodynamic Equilibrium(NLTE) stellar atmosphere computer code which can handle very large model atoms/molecules as well as line blanketing by hundreds of millions of atomic and molecular lines. The code is used to compute model atmospheres and synthetic spectra (solution of the radiative transport e...

  13. Volume 1 Chapter 2: Emissions and concentrations of radiatively active atmospheric trace constituents

    OpenAIRE

    W. Winiwarter

    2014-01-01

    Radiatively active atmospheric trace constituents consist of the following groups of compounds: long-lived greenhouse gases with residence times of years, subject to international conventions; short-lived gases formed in the atmosphere from precursor compounds, remaining in the atmosphere for hours or days: notably ozone; and aerosols, that is, airborne particles interacting with short-wave radiation with both direct and indirect effects. The "direct effect" covers scattering or absorption of...

  14. Polarimetry of hot-Jupiter systems and radiative transfer models of planetary atmospheres

    Science.gov (United States)

    Bott, Kimberly; Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Cotton, Daniel; Marshall, Jonathan

    2016-01-01

    Thousands of exoplanets and planet candidates have been detected. The next important step in the contexts of astrobiology, planetary classification and planet formation is to characterise them. My dissertation aims to provide further characterisation to four hot Jupiter exoplanets: the relatively well-characterised HD 189733b, WASP-18b which is nearly large enough to be a brown dwarf, and two minimally characterised non-transiting hot Jupiters: HD 179949b and tau Bootis b.For the transiting planets, this is done through two means. First, published data from previous observations of the secondary eclipse (and transit for HD 189733b) are compared to models created with the Versatile Software for the Transfer of Atmospheric Radiation (VSTAR). Second, new polarimetric observations from the HIgh Precision Polarimetric Instrument are compared to Lambert-Rayleigh polarised light phase curves. For the non-transiting planets, only the polarimetric measurements are compared to models, but toy radiative transfer models are produced for concept. As an introduction to radiative transfer models, VSTAR is applied to the planet Uranus to measure its D/H isotope ratio. A preliminary value is derived for D/H in one part of the atmosphere.Fitting a single atmospheric model to the transmitted, reflected, and emitted light, I confirm the presence of water on HD 189733b, and present a new temperature profile and cloud profile for the planet. For WASP-18b, I confirm the general shape of the temperature profile. No conclusions can be drawn from the polarimetric measurements for the non-transiting planets. I detect a possible variation with phase for transiting planet WASP-18b but cannot confirm it at this time. Alternative sources to the planet are discussed. For HD 189733b, I detect possible variability in the polarised light at the scale expected for the planet. However, the data are also statistically consistent with no variability and are not matched to the phase of the planet.

  15. Measurement of $\\psip$ Radiative Decays

    OpenAIRE

    Ablikim, M.; Bai, J. Z.; Y. Ban; Collaboration, BES

    2006-01-01

    Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\\bar K^{*0}, gamma pi^+pi^- p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with the invariant mass of hadrons below 2.9GeV/c^2. We also report branching fractions of psi(2S) decays into 2(pi^+...

  16. Modeling atmospheric longwave radiation at the surface during overcast skies: The role of cloud base height

    Science.gov (United States)

    Viúdez-Mora, A.; Costa-Surós, M.; Calbó, J.; González, J. A.

    2015-01-01

    behavior of the atmospheric downward longwave radiation at the surface under overcast conditions is studied. For optically thick clouds, longwave radiation depends greatly on the cloud base height (CBH), besides temperature and water vapor profiles. The CBH determines the cloud emission temperature and the air layers contributing to the longwave radiation that reaches the surface. Overcast situations observed at Girona (NE Iberian Peninsula) were studied by using a radiative transfer model. The data set includes different seasons, and a large range of CBH (0-5000 m). The atmosphere profiles were taken from the European Center for Medium-Range Weather Forecast analysis. The CBH was determined from ceilometer measurements and also estimated by using a suitable method applied to the vertical profile of relative humidity. The agreement between calculations and pyrgeometer measurements is remarkably good (1.6 ± 6.2 W m-2) if the observed CBH is used; poorer results are obtained with the estimated CBH (4.3 ± 7.0 W m-2). These results are better than those obtained from a simple parameterization based upon ground-level data (1.1 ± 11.6 W m-2), which can be corrected by adding a term that takes into account the CBH (-0.1 ± 7.3 W m-2). At this site, the cloud radiative effect (CRE) at the surface lies in the range 50-80 W m-2, has a clear seasonal behavior (higher CRE in winter), and depends upon the CBH. For the cold and the warm seasons, CRE decreases with CBH at a rate of -5 and -4 W m-2/km, respectively. Results obtained for other climates (subarctic and tropical) are also presented.

  17. Addition Laws for Intensities of Radiation Emerging from Scattering Atmospheres Containing Energy Sources

    Science.gov (United States)

    Nikoghossian, A. G.; Kapanadze, N. G.

    2016-03-01

    A group theoretical approach is developed for solving astrophysical radiative transfer problems described in a previous series of papers. Addition laws for observed radiative intensities are derived for the case in which atmospheres not only absorb and scatter radiation incident on them, but radiate themselves because of energy sources contained within them. As an illustration of the application of these laws, several special radiative transfer problems which we believe are of practical interest are discussed.

  18. Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

    Science.gov (United States)

    Rodriguez, M.; Riris, H.; Abshire, J. B.; Allan, G. R.; Stephen, M.; Hasselbrack, W.; Mao, J.

    2012-12-01

    We report on airborne atmospheric pressure measurements using fiber-based laser technology and the oxygen A-band at 765 nm. Remote atmospheric temperature and pressure measurements are needed for NASA's Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. ASCENDS will measure atmospheric CO2 dry mixing ratios on a global scale. Remote atmospheric pressure measurements are necessary to normalize ASCENDS CO2 measurements. Our work, funded by the ESTO IIP program, uses erbium doped fiber optic amplifiers and non-linear optics technology to tune laser radiation over the Oxygen A-band between 764.5 nm and 765 nm. Surface reflections are fiber-coupled from a receiver telescope to photon counting detectors. Our pulsed, time gated approach resolves ground reflections from cloud returns. This system successfully recorded O2 absorption spectra during two airborne campaigns aboard a NASA DC-8. Airborne data has been analyzed and fitted to HITRAN reference spectra based upon aircraft meteorological data. Our algorithm linearly scales the HITRAN reference until measurement errors are minimized. Atmospheric pressure changes are estimated by comparing the differential optical depth of the optimum scaled HITRAN spectra to the differential optical depth of the nominal HITRAN spectra. On flights over gradually sloping terrain, these results compare favorably with ground-based observations and predictions from computer models. Measurement uncertainty is commensurate with photon counting noise. We plan to reduce measurement uncertainty in future campaigns by improving transmitter pulse energy and increasing wavelength sweep frequency.

  19. Atmospheric radiative transfer parametrization for solar energy yield calculations on buildings

    CERN Document Server

    Wagner, Jochen E

    2015-01-01

    In this paper the practical approach to evaluate the incoming solar radiation on buildings based on atmospheric composition and cloud cover is presented. The effects of absorption and scattering due to atmospheric composition is taken into account to calculate, using radiative transfer models, the net incoming solar radiation at surface level. A specific validation of the Alpine Region in Europe is presented with a special focus on the region of South Tyrol.

  20. Recent measurements of coherent transition radiation

    International Nuclear Information System (INIS)

    An extended series of experiments has been used to investigate transition radiation in the x-ray spectral region. The x-rays were generated at the Lawrence Livermore National Laboratory electron-positron linear accelerator by 54 MeV electrons traversing multiple thin-foil targets. The measured angular and spectral distributions have shown excellent agreement with calculated predictions based on a simplified theoretical description of transition radiation. Recently, energy-resolved measurements of x-ray generation by targets consisting of multiple closely-spaced foils has clearly demonstrated the longitudinal coherence of transition radiation. This behavior might lead to a variety of applications such as tuneable narrow-band x-ray sources, measurement of x-ray dielectric constants, or particle beam diagnostics. These issues will be discussed, and recent results will be presented

  1. Radiation effects on the laser ablative shockwaves from aluminum under atmospheric conditions

    International Nuclear Information System (INIS)

    The evolution of laser ablative shockwaves (LASW) from Aluminum under atmospheric pressures is numerically modeled using a one-dimensional, three-temperature (electron, ion and thermal radiation temperatures), non-equilibrium, radiation hydrodynamic (RHD) model. The governing RHD equations in Lagrangian form are solved by using an implicit scheme. Similarly, the energy relaxation between the electrons and ions and the electrons and thermal radiation are determined implicitly. Apart from these, the energy equation takes into account the flux-limited electron thermal heat flux. The RHD equations are closed by using a two temperature QEOS model for the Al. The MULTI-fs code is modified to incorporate the nanosecond laser absorption model via the photoionization (PI) and the inverse bremsstrahlung (IB) processes. The spatio-temporal evolution of the laser ablative shockwaves generated by focusing a second harmonic (532 nm, 7ns) of Nd:YAG laser on to Aluminum target under atmospheric pressures in air is captured using a shadowgraphy technique. These measurements are made from 200 ns to 10 μs after the laser pulse with a temporal resolution of 1.5 ns. We report the details of the RHD model and compare the simulated and experimental results for input laser energies in the range of 25 - 175 mJ per pulse. The evolution of the plasma parameters like electron density, charge states and the shockwaves launched into the ambient atmosphere due to expanding plasma plume are compared. The role of thermal radiation on the evolution of LASW from Al is discussed. (author)

  2. Development of radiation protection and measurement technology

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Si Young; Lee, T. Y.; Kim, J. L.; Kim, B. H.; Lee, B. J.; Chung, K. K.; Lee, K. C.; Chung, R. I.; Han, Y. D.; Kim, J. S.; Lee, H. S.; Kim, C. K.; Yoon, K. S.; Jeong, D. Y.; Yoon, S. C.; Yoon, Y. C.; Lee, S. Y.; Kim, J. S.; Seo, K. W. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, J. K.; Lee, J. K. [Hanyang Univ., Seoul (Korea, Republic of)

    1997-07-01

    Reference X-, gamma, beta and neutron radiation fields complying with the ISO and ANSI standards have been established and evaluated to provide a basic technical support in national radiation protection dosimetry program and to provide calibration measurement devices. Personal dose evaluation algorithm has been developed with these reference radiation fields, which comply well with both domestic and the new ANSI N13.11, to evaluate accurate personal dose equivalents. A personal internal dosimetry algorithm which can estimate the intakes of radionuclides from the results of in vivo bioassay and the resulting internal doses has been developed and verified its performance. It was also evaluated to be equality excellent compared with those being used in foreign countries and used to make a computer code for internal dose evaluation which can be run with PC under the Windows environment. A BOMAB phantom for precise calibration of in vivo system has been also designed, fabricated and test-evaluated. Based on the ALARA concept of the optimization principle of radiation protection, a method for estimating the cost for radiation protection has been studied and an objective monetary cost of detriment due to radiation exposure, called {alpha} value ($/man-Sv) has been derived and proposed based on the Korean socio-economic situation and human risk factors to provide basic data for the radiation protection optimization study in Korea. (author). 100 refs., 104 tabs., 69 figs.

  3. Development of radiation protection and measurement technology

    International Nuclear Information System (INIS)

    Reference X-, gamma, beta and neutron radiation fields complying with the ISO and ANSI standards have been established and evaluated to provide a basic technical support in national radiation protection dosimetry program and to provide calibration measurement devices. Personal dose evaluation algorithm has been developed with these reference radiation fields, which comply well with both domestic and the new ANSI N13.11, to evaluate accurate personal dose equivalents. A personal internal dosimetry algorithm which can estimate the intakes of radionuclides from the results of in vivo bioassay and the resulting internal doses has been developed and verified its performance. It was also evaluated to be equality excellent compared with those being used in foreign countries and used to make a computer code for internal dose evaluation which can be run with PC under the Windows environment. A BOMAB phantom for precise calibration of in vivo system has been also designed, fabricated and test-evaluated. Based on the ALARA concept of the optimization principle of radiation protection, a method for estimating the cost for radiation protection has been studied and an objective monetary cost of detriment due to radiation exposure, called α value ($/man-Sv) has been derived and proposed based on the Korean socio-economic situation and human risk factors to provide basic data for the radiation protection optimization study in Korea. (author). 100 refs., 104 tabs., 69 figs

  4. Radiation dose calculations at different atmospheric stability categories for yatagan coal-fired power plant

    International Nuclear Information System (INIS)

    Radiation dose calculations at different atmospheric stability categories have been carried out by the code CAP88-PC around the Yatagan coal-fired power plant environment by using the results of previous studies about maximum measured gross alpha activity in the flying ash samples as radioactive sources. A modified Gaussian plume equation was used to estimate the average dispersion of radionuclides released from up to six emitting sources for a circular grid of distances and directions for a radius of up to 80 kilometers around the facility. The meteorological data obtained from Turkish State Meteorological Service for Yatagan region was processed to find out the stability array file consists of 4 different wind frequencies, one for each of the 16 wind directions on 6 Pas quill stability categories.16 records were entered for each Pa squill stability category and wind frequencies. The maximum effective dose equivalent rates for each atmospheric stability category and their radiological effects have been interpreted

  5. Features of the flux of gamma-radiation in the lower atmosphere during precipitation

    International Nuclear Information System (INIS)

    We are carrying out observations and studies of increases of gamma radiation intensity in a ground atmosphere layer during precipitations. Measurements have been carried out in two high-altitude points: Apatity (Murmansk) and Barentsburg (Spitsbergen). Scintillation detectors on the basis of NaI(Tl) crystals are used. Continuous radiation detection is made as the count rate in integral channels with threshold values >20 keV, >100 keV. There are more than 500 events of increase in gamma-ray background during precipitation. Average profiles of X-ray radiation increases in a ground level and the related with them increases of intensity of precipitations for stations in Apatity and Barentsburg have been built up. In Apatity the average increase profile in the gamma-ray flux and accompanying with profile of precipitations rate have been obtained. A time gap between peaks of precipitation and increase one is 30-40 minutes. A barometric coefficient of each component of radiation has been calculated. The barometric coefficient has a zero value on gamma-ray. The charged component of the secondary cosmic rays has a typical value ∼0.18 %/mB. The lack of the barometric effect on gamma-ray indicates on the local origin of this radiation.

  6. Measurement of Radiated Power Loss on EAST

    Institute of Scientific and Technical Information of China (English)

    段艳敏; 王亮; 胡立群; 毛松涛; 许平; 陈开云; 林士耀; 钟国强; 张继宗; 张凌

    2011-01-01

    A type of silicon detector known as AXUV (absolute extreme ultraviolet) photodiodes is successfully used to measure the radiated power in EAST. The detector is characterized by compact structure, fast temporal response (〈0.5 s) and flat spectral sensitivity in the range from ultra-violet to X-ray. Two 16-channel AXUV arrays are installed in EAST to view the whole poloidal cross-section of plasma. Based on the diagnostic system, typical radiation distributions for both limiter and divertor plasma are obtained and compared. As divertor detachment occurs, the radiation distribution in X-point region is observed to vary distinctly. The total radiation power losses in discharges with different plasma parameters are briefly analyzed.

  7. Aircrew radiation exposure: sources-risks-measurement

    International Nuclear Information System (INIS)

    A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

  8. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale

    International Nuclear Information System (INIS)

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value

  9. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale

    Science.gov (United States)

    Kawamura, Yoshiyuki

    2016-01-01

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value.

  10. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale.

    Science.gov (United States)

    Kawamura, Yoshiyuki

    2016-01-01

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO2) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO2 gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value. PMID:26827362

  11. Note: Measurement system for the radiative forcing of greenhouse gases in a laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Yoshiyuki [Department of Intelligent Mechanical Engineering, Fukuoka Institute of Technology, 3-30-1 Wajirohigashi, Higashiku, Fukuoka 811-0295 (Japan)

    2016-01-15

    The radiative forcing of the greenhouse gases has been studied being based on computational simulations or the observation of the real atmosphere meteorologically. In order to know the greenhouse effect more deeply and to study it from various viewpoints, the study on it in a laboratory scale is important. We have developed a direct measurement system for the infrared back radiation from the carbon dioxide (CO{sub 2}) gas. The system configuration is similar with that of the practical earth-atmosphere-space system. Using this system, the back radiation from the CO{sub 2} gas was directly measured in a laboratory scale, which roughly coincides with meteorologically predicted value.

  12. Radiation and Heat Transfer in the Atmosphere: A Comprehensive Approach on a Molecular Basis

    Directory of Open Access Journals (Sweden)

    Hermann Harde

    2013-01-01

    Full Text Available We investigate the interaction of infrared active molecules in the atmosphere with their own thermal background radiation as well as with radiation from an external blackbody radiator. We show that the background radiation can be well understood only in terms of the spontaneous emission of the molecules. The radiation and heat transfer processes in the atmosphere are described by rate equations which are solved numerically for typical conditions as found in the troposphere and stratosphere, showing the conversion of heat to radiation and vice versa. Consideration of the interaction processes on a molecular scale allows to develop a comprehensive theoretical concept for the description of the radiation transfer in the atmosphere. A generalized form of the radiation transfer equation is presented, which covers both limiting cases of thin and dense atmospheres and allows a continuous transition from low to high densities, controlled by a density dependent parameter. Simulations of the up- and down-welling radiation and its interaction with the most prominent greenhouse gases water vapour, carbon dioxide, methane, and ozone in the atmosphere are presented. The radiative forcing at doubled CO2 concentration is found to be 30% smaller than the IPCC-value.

  13. Radiation measurements aboard the fourth Gemini flight.

    Science.gov (United States)

    Janni, J F; Schneider, M F

    1967-01-01

    Two special tissue-equivalent ionization chambers and 5 highly sensitive passive dosimetry packages were flown aboard the recent Gemini 4 flight for the purpose of obtaining precise values of instantaneous dose rate, accumulated dose. and shielding effectiveness. This experiment marked the first time that well-defined tissue dose and radiation survey measurements have been carried out in manned spaceflight operations. Since all measurements were accomplished under normal spacecraft environmental conditions, the biological dose resulted primarily from trapped inner Van Allen Belt radiation encountered by the spacecraft in the South Atlantic Anomaly. The experiment determined the particle type, ionizing and penetrating power, and variation with time and position within the Gemini spacecraft. Measured dose rates ranged from 100 mrad/hr for passes penetrating deeply into the South Atlantic Anomaly to less than 0.1 mrad/hr from lower latitude cosmic radiation. The accumulated tissue dose measured by the active ionization chambers, shielded by 0.4 gm/cm2 for the 4-day mission, was 82 mrad. Since the 5 passive dosimetry packages were each located in different positions within the spacecraft, the total mission surface dose measured by these detectors varied from 73 to 27 mrad, depending upon location and shielding. The particles within the spacecraft were recorded in nuclear emulsion, which established that over 90% of the tissue dose was attributable to penetrating protons. This experiment indicates that the radiation environment under shielded conditions at Gemini altitudes was not hazardous. PMID:11973852

  14. Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems (ERASMUS)

    Energy Technology Data Exchange (ETDEWEB)

    Bland, Geoffrey [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)

    2016-06-30

    The use of small unmanned aircraft systems (sUAS) with miniature sensor systems for atmospheric research is an important capability to develop. The Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems (ERASMUS) project, lead by Dr. Gijs de Boer of the Cooperative Institute for Research in Environmental Sciences (CIRES- a partnership of NOAA and CU-Boulder), is a significant milestone in realizing this new potential. This project has clearly demonstrated that the concept of sUAS utilization is valid, and miniature instrumentation can be used to further our understanding of the atmospheric boundary layer in the arctic.

  15. Millimeter radiation from a 3D model of the solar atmosphere I. Diagnosing chromospheric thermal structure

    CERN Document Server

    Loukitcheva, Maria; Carlsson, Mats; White, Stephen

    2015-01-01

    Aims. We use advanced 3D NLTE radiative magnetohydrodynamic simulations of the solar atmosphere to carry out detailed tests of chromospheric diagnostics at millimeter and submillimeter wavelengths. Methods. We focused on the diagnostics of the thermal structure of the chromosphere in the wavelength bands from 0.4 mm up to 9.6 mm that can be accessed with the Atacama Large Millimeter/Submillimeter Array (ALMA) and investigated how these diagnostics are affected by the instrumental resolution. Results. We find that the formation height range of the millimeter radiation depends on the location in the simulation domain and is related to the underlying magnetic structure. Nonetheless, the brightness temperature is a reasonable measure of the gas temperature at the effective formation height at a given location on the solar surface. There is considerable scatter in this relationship, but this is significantly reduced when very weak magnetic fields are avoided. Our results indicate that although instrumental smearin...

  16. Neutron measuring instruments for radiation protection

    International Nuclear Information System (INIS)

    The present report deals with selected topics from the field of neutron dosimetry for radiation protection connected with the work of the subcommittee 6802 in the Standards Committee on Radiology (NAR) of the German Standards Institute (DIN). It is a sort of material collection. The topics are: 1. Measurement of the absorbed-energy dose by a) ionization chambers in fields of mixed radiation and b) recoil-proton proportional counting tubes. 2. Measurement of the equivalent dose, neutron monitors, combination methods by a) rem-meters, b) recoil-proton counting tubes, c) recombination method, tissue-equivalent proportional counters, activation methods for high energies in fields of mixed radiation, d) personnel dosimetry by means of ionization chambers and counting tubes, e) dosimetry by means of activation methods, nuclear track films, nonphotographic nuclear track detectors and solid-state dosimeters. (orig./HP)

  17. Absorption of infra-red radiation by atmospheric molecular cluster-ions

    CERN Document Server

    Aplin, K L

    2005-01-01

    Protonated water clusters are a common species of atmospheric molecular cluster-ion, produced by cosmic rays throughout the troposphere and stratosphere. Under clear-sky conditions or periods of increased atmospheric ionisation, such as solar proton events, the IR absorption by atmospheric ions may affect climate through the radiative balance. Fourier Transform Infrared Spectrometry in a long path cell, of path length 545m, has been used to detect IR absorption by corona-generated positive molecular cluster-ions. The column concentration of ions in the laboratory spectroscopy experiment was estimated to be ~10^13 m-2; the column concentration of protonated atmospheric ions estimated using a simple model is ~10^14 m-2. Two regions of absorption, at 12.3 and 9.1 um are associated with enhanced ion concentrations. After filtering of the measured spectra to compensate for spurious signals from neutral water vapour and residual carbon dioxide, the strongest absorption region is at 9.5 to 8.8 um (1050 to 1140 cm-1)...

  18. Comparison of Martian Surface Radiation Predictions to the Measurements of Mars Science Laboratory Radiation Assessment Detector (MSL/RAD)

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.; Zeitlin, Cary; Hassler, Donald M.; Ehresmann, Bent; Rafkin, Scot C. R.; Wimmer-Schweingruber, Robert F; Boettcher, Stephan; Boehm, Eckart; Guo, Jingnan; Koehler, Jan; Martin, Cesar; Reitz, Guenther; Posner, Erik

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, detailed knowledge of particle spectra is an important factor. Detailed measurements of the energetic particle radiation environment on the surface of Mars have been made by the Mars Science Laboratory Radiation Assessment Detector (MSL-RAD) on the Curiosity rover since August 2012, and particle fluxes for a wide range of ion species (up to several hundred MeV/u) and high energy neutrons (8 - 1000 MeV) have been available for the first 200 sols. Although the data obtained on the surface of Mars for 200 sols are limited in the narrow energy spectra, the simulation results using the Badhwar-O'Neill galactic cosmic ray (GCR) environment model and the high-charge and energy transport (HZETRN) code are compared to the data. For the nuclear interactions of primary GCR through Mars atmosphere and Curiosity rover, the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) is used, which includes direct knockout, evaporation and nuclear coalescence. Daily atmospheric pressure measurements at Gale Crater by the MSL Rover Environmental Monitoring Station are implemented into transport calculations for describing the daily column depth of atmosphere. Particles impinging on top of the Martian atmosphere reach the RAD after traversing varying depths of atmosphere that depend on the slant angles, and the model accounts for shielding of the RAD by the rest of the instrument. Calculations of stopping particle spectra are in good agreement with the RAD measurements for the first 200 sols by accounting changing heliospheric conditions and atmospheric pressure. Detailed comparisons between model predictions and spectral data of various particle types provide the validation of radiation transport models, and thus increase the accuracy of the predictions of future radiation environments on Mars. These contributions lend support to the understanding of radiation health risks to

  19. The SARTre model for radiative transfer in spherical atmospheres and its application to the derivation of cirrus cloud properties

    Energy Technology Data Exchange (ETDEWEB)

    Mendrock, J.

    2006-07-01

    Modeling of radiative transfer (RT) is one of the essentials of atmospheric remote sensing. It has been common to use separate models for the simulation of shortwave radiation dominated by scattering of sunlight and longwave radiation characterized by emission from trace gases. These days also shortwave instruments are operated in limb mode, which demand models taking the sphericity of the Earth and atmosphere into account. On the other hand, infrared and microwave sounders are increasingly being used for the observation of ice clouds, that necessitate the modeling of scattering by cloud particles. Both trends require RT models, that are capable of taking into account scattering as well as the sphericity of the atmosphere. This suggests a unified handling of short- and longwave radiation, which furthermore allows for a consistent evaluation of multispectral data. Focusing on these aspects, the RT-model SARTre ([Approximate] Spherical Atmospheric Radiative Transfer model) has been developed. To our knowledge, SARTre is the first model, that is capable of limb modeling in the ultraviolet, visible, near to far infrared, and microwave spectral region. Here, algorithm baseline, implementation, verification and validation of SARTre are presented. SARTre has been used to study effects of cirrus clouds on infrared limb emission spectra. An exemplary retrieval of cirrus parameters from MIPAS measurements is demonstrated, and the plausibility of the results is discussed. (orig.)

  20. Automatic radiation measuring system connected with GPS

    International Nuclear Information System (INIS)

    The most serious nuclear disaster in Japan has broken out at Fukushima Daiichi Nuclear Power Plant due to Great East Japan Earthquake. Prompt and exact mapping of the contamination is of great importance for radiation protection and for the environment restoration. We have developed radiation survey systems KURAMA and KURAMA-2 for rapid and exact measurement of radiation dose distribution. The system is composed of a mobile radiation monitor and the computer in office which is for the storage and visualization of the data. They are connected with internet and are operated for continuous radiation measurement while the monitor is moving. The mobile part consists of a survey meter, an interface to transform the output of the survey meter for the computer, a global positioning system, a computer to process the data for connecting to the network, and a mobile router. Thus they are effective for rapid mapping of the surface contamination. The operation and the performance of the equipment at the site are presented. (J.P.N.)

  1. Short-wave solar radiation in the earths atmosphere calculation, observation, interpretation

    CERN Document Server

    Melnikova, Irina N

    2005-01-01

    Based on data from an experiment which ran for ten years, this book summarizes the results of the Atmospheric Physics Department of the St. Petersburg University and the Main Geophysical Observatory. The processed data now forms a rich dataset of spectral values of radiative characteristics under different atmospheric conditions. The analysis of this database clearly shows that the solar radiative absorption in a dusty and cloudy atmosphere is significantly higher than assumed to date. Both graduate students of atmospheric sciences as well as scientists and researchers in the field of meteorology and climatology will find a wealth of new data and information in this monograph.

  2. Web based Measurement System for Solar Radiation

    Directory of Open Access Journals (Sweden)

    Shachi Awasthi

    2012-06-01

    Full Text Available We present in this paper, the principles of the measurement system for solar radiation, and our implementation using Web based data logging concept. The photocurrent produced by Silicon PN junction is used as a solar radiation transducer, to make it more viable we have used commercially available solar panels as our transducers. Using a silicon solar cell as sensor, a low cost solar radiometer can be constructed. The photocurrent produced by solar cell is electronically tailored to be measured and stored by our web based data acquisition and monitoring system. Measurement using real solar cell array gives a good measure of actual producible energy by solar arrays. Our portable instrument can be used in remote sites and substitutes the solar monitor and integrator, Current data of solar radiation can be monitored using Ethernet interface available in all PC, Laptops. We store the data into a secure digital card which can be retrieved to plot and analyse the data. We have developed system hardware and software based on ATmega32 AVR Microcontrollers and ENC28J60 Ethernet PHY and MAC network interface chip by Microchip. So the global irradiance data are obtained after correction using the instantaneous measurement of ambient temperature which allows us to calculate the junction temperature and consequently improve the precision of measurement of our data acquisition system.

  3. The measurement of solar ultraviolet radiation.

    Science.gov (United States)

    Roy, C R; Gies, H P; Lugg, D J; Toomey, S; Tomlinson, D W

    1998-11-01

    High skin cancer rates, stratospheric ozone depletion and increased public interest and concern have resulted in a strong demand for solar ultraviolet radiation measurements and information. The Australian Radiation Laboratory (ARL) has been involved since the mid-1980s in the measurement of solar ultraviolet radiation (UVR) using spectroradiometers (SRM) and a network of broadband detectors at 18 sites in Australia and Antarctica and in Singapore through a collaborative agreement with the Singapore Institute of Science and Forensic Medicine. Measurement locations range from equatorial (Singapore, 1.3 degrees N) through tropical (Darwin, 12.4 degrees S) to polar (Mawson, 67.6 degrees S) and as a result there are many difficulties associated with maintenance and calibration of the network detectors, and transfer of data to ensure an accurate and reliable data collection. Calibration procedures for the various detectors involve the comparison with simultaneous spectral measurements using a portable SRM incorporating a double monochromator, calibrated against traceable standard lamps. Laboratory measurements of cosine response and responsivity are also made. Detectors are intercompared at the Yallambie site for a number of months before installation at another location. As an additional check on the calibrations, computer models of solar UVR at the earth's surface for days with clear sky and known ozone are compared with the UV radiometer measurements. PMID:9920423

  4. Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

    DEFF Research Database (Denmark)

    Drews, Martin; Lauritzen, Bent; Madsen, Henrik

    2005-01-01

    A Kalman filter method is discussed for on-line estimation of radioactive release and atmospheric dispersion from a time series of off-site radiation monitoring data. The method is based on a state space approach, where a stochastic system equation describes the dynamics of the plume model...... parameters, and the observables are linked to the state variables through a static measurement equation. The method is analysed for three simple state space models using experimental data obtained at a nuclear research reactor. Compared to direct measurements of the atmospheric dispersion, the Kalman filter...... estimates are found to agree well with the measured parameters, provided that the radiation measurements are spread out in the cross-wind direction. For less optimal detector placement it proves difficult to distinguish variations in the source term and plume height; yet the Kalman filter yields consistent...

  5. Atmospheric propagation of high power laser radiation at different weather conditions

    Science.gov (United States)

    Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Handke, Jürgen

    2016-05-01

    Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations between weather condition and laser beam characteristics DLR operates at Lampoldshausen a 130 m long free transmission laser test range. Sensors around this test range continuously monitor turbulence strength, visibility, precipitation, temperature, and wind speed. High power laser radiation is obtained by a TruDisk 6001 disk laser (Trumpf company) yielding a maximum output power of 6 kW at a wavelength of 1030 nm. The laser beam is expanded to 180 mm and focused along the beam path. Power and intensity distribution are measured before and after propagation, providing information about the atmospheric transmission and alterations of diameter and position of the laser beam. Backscattered laser light is acquired by a photo receiver. As a result, measurements performed at different weather conditions show a couple of correlations to the characteristics of the laser beam. The experimental results are compared to a numerical analysis. The calculations are based on the Maxwell wave equation in Fresnel approximation. The turbulence is considered by the introduction of phase screens and the "von Karman" spectrum.

  6. Silica aerogel radiators for bunch length measurements

    International Nuclear Information System (INIS)

    Cherenkov radiators based on silica aerogel are used to measure the electron bunch length at the photo injector test facility at DESY Zeuthen (PITZ). The energy range of those electrons is 4-5 MeV. In this paper, the time resolution defined by the usage of aerogel is calculated analytically and Monte Carlo simulations are performed. It is shown that silica aerogel gives the possibility to reach a time resolution of about 0.1 ps for high photon intensities and a time resolution of about 0.02 ps can be obtained for thin silica aerogel radiators

  7. Solar Radiation Measurements Onboard the Research Aircraft HALO

    Science.gov (United States)

    Lohse, I.; Bohn, B.; Werner, F.; Ehrlich, A.; Wendisch, M.

    2014-12-01

    Airborne measurements of the separated upward and downward components of solar spectral actinic flux densities for the determination of photolysis frequencies and of upward nadir spectral radiance were performed with the HALO Solar Radiation (HALO-SR) instrument package onboard the High Altitude and Long Range Research Aircraft (HALO). The instrumentation of HALO-SR is characterized and first measurement data from the Next-generation Aircraft Remote-Sensing for Validation Studies (NARVAL) campaigns in 2013 and 2014 are presented. The measured data are analyzed in the context of the retrieved microphysical and optical properties of clouds which were observed underneath the aircraft. Detailed angular sensitivities of the two optical actinic flux receivers were determined in the laboratory. The effects of deviations from the ideal response are investigated using radiative transfer calculations of atmospheric radiance distributions under various atmospheric conditions and different ground albedos. Corresponding correction factors are derived. Example photolysis frequencies are presented, which were sampled in the free troposphere and lower stratosphere over the Atlantic Ocean during the 2013/14 HALO NARVAL campaigns. Dependencies of photolysis frequencies on cloud cover, flight altitude and wavelength range of the photolysis process are investigated. Calculated actinic flux densities in the presence of clouds benefit from the measured spectral radiances. Retrieved cloud optical thicknesses and effective droplet radii are used as model input for the radiative transfer calculations. By comparison with the concurrent measurements of actinic flux densities the retrieval approach is validated. Acknowledgements: Funding by the Deutsche Forschungsgemeinschaft within the priority program HALO (BO 1580/4-1, WE 1900/21-1) is gratefully acknowledged.

  8. Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems (ERASMUS) Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    de Boer, G [University of Colorado, Boulder/CIRES; Argrow, B [University of Colorado; Bland, G [NASA - Goddard Space Flight Center - Wallops Flight Facility; Elston, J [University of Colorado, Boulder; Lawrence, D [University of Colorado; Maslanik, J [University of Colorado; Palo, S [University of Colorado; Tschudi, M [NCAR

    2015-12-01

    The use of unmanned aerial systems (UAS) is becoming increasingly popular for a variety of applications. One way in which these systems can provide revolutionary scientific information is through routine measurement of atmospheric conditions, particularly properties related to clouds, aerosols, and radiation. Improved understanding of these topics at high latitudes, in particular, has become very relevant because of observed decreases in ice and snow in polar regions.

  9. Skill Assessment of a Spectral Ocean-Atmosphere Radiative Model

    Science.gov (United States)

    Gregg, Watson, W.; Casey, Nancy W.

    2009-01-01

    Ocean phytoplankton, detrital material, and water absorb and scatter light spectrally. The Ocean- Atmosphere Spectral Irradiance Model (OASIM) is intended to provide surface irradiance over the oceans with sufficient spectral resolution to support ocean ecology, biogeochemistry, and heat exchange investigations, and of sufficient duration to support inter-annual and decadal investigations. OASIM total surface irradiance (integrated 200 nm to 4 microns) was compared to in situ data and three publicly available global data products at monthly 1-degree resolution. OASIM spectrally-integrated surface irradiance had root mean square (RMS) difference= 20.1 W/sq m (about 11%), bias=1.6 W/sq m (about 0.8%), regression slope= 1.01 and correlation coefficient= 0.89, when compared to 2322 in situ observations. OASIM had the lowest bias of any of the global data products evaluated (ISCCP-FD, NCEP, and ISLSCP 11), and the best slope (nearest to unity). It had the second best RMS, and the third best correlation coefficient. OASIM total surface irradiance compared well with ISCCP-FD (RMS= 20.7 W/sq m; bias=-11.4 W/sq m, r=0.98) and ISLSCP II (RMS =25.2 W/sq m; bias= -13.8 W/sq m; r=0.97), but less well with NCEP (RMS =43.0 W/sq m ;bias=-22.6 W/sq m; x=0.91). Comparisons of OASIM photosynthetically available radiation (PAR) with PAR derived from SeaWiFS showed low bias (-1.8 mol photons /sq m/d, or about 5%), RMS (4.25 mol photons /sq m/d ' or about 12%), near unity slope (1.03) and high correlation coefficient (0.97). Coupled with previous estimates of clear sky spectral irradiance in OASIM (6.6% RMS at 1 nm resolution), these results suggest that OASIM provides reasonable estimates of surface broadband and spectral irradiance in the oceans, and can support studies on ocean ecosystems, carbon cycling, and heat exchange.

  10. Deviating measurements in radiation protection. Legal assessment of deviations in radiation protection measurements

    International Nuclear Information System (INIS)

    This study investigates how, from a legal point of view, deviations in radiation protection measurements should be treated in comparisons between measured results and limits stipulated by nuclear legislation or goods transport regulations. A case-by-case distinction is proposed which is based on the legal concequences of the respective measurement. Commentaries on nuclear law contain no references to the legal assessment of deviating measurements in radiation protection. The examples quoted in legal commentaries on civil and criminal proceedings of the way in which errors made in measurements for speed control and determinations of the alcohol content in the blood are to be taken into account, and a commentary on ozone legislation, are examined for analogies with radiation protection measurements. Leading cases in the nuclear field are evaluated in the light of the requirements applying in case of deviations in measurements. The final section summarizes the most important findings and conclusions. (orig.)

  11. Simultaneous measurements of atmospheric emissions at 10, 33 and 90 GHz

    International Nuclear Information System (INIS)

    As part of a larger experiment to measure the cosmic microwave background radiation spectrum, frequent simultaneous measurements of the microwave thermal emission from the earth's atmosphere were made at three fixed frequencies, namely, 10 GHz, 33 GHz and 90 GHz. We performed these measurements at two separate locations, Berkeley and White Mountain, which greatly differed in altitude and climatic conditions. Typical values measured in Berkeley of the atmospheric antenna temperature during good weather are 3.13 +- 0.300K, 12.3 +- 0.30K and 34.6 +- 0.50K, for 10, 33, and 90 GHz respectively. Corresponding values measured at White Mountain are 1.15 +- 0.10K, 4.51 +- 0.180K and 11.0 +- 0.20K. Because the measurements are simultaneous in nature, correlations between the measurements taken at the various frequencies provide constraints on models of the microwave emission of the earth's atmosphere, especially models describing atmospheric emission as a function of precipitable water content

  12. Statistics for Radiation Measurement. Chapter 5

    International Nuclear Information System (INIS)

    Measurement errors are of three general types: (i) blunders, (ii) systematic errors or accuracy of measurements, and (iii) random errors or precision of measurements. Blunders produce grossly inaccurate results and experienced observers easily detect their occurrence. Examples in radiation counting or measurements include the incorrect setting of the energy window, counting heavily contaminated samples, using contaminated detectors for imaging or counting, obtaining measurements of high activities, resulting in count rates that lead to excessive dead time effects, and selecting the wrong patient orientation during imaging. Although some blunders can be detected as outliers or by duplicate samples and measurements, blunders should be avoided by careful, meticulous and dedicated work. This is especially important where results will determine the diagnosis or treatment of patients

  13. Measuring and prediction of global solar ultraviolet radiation (0295-0385 μ m) under clear and cloudless skies

    International Nuclear Information System (INIS)

    Values of global solar ultraviolet radiation were measured with an ultraviolet radiometer and also predicted with a atmospheric spectral model. The values obtained with the atmospheric spectral model, based physically, were analyzed and compared with experimental values measured in situ. Measurements were performed for different zenith angles in conditions of clear skies in Heredia, Costa Rica. The necessary input data include latitude, altitude, surface albedo, Earth-Sun distance, as well as atmospheric characteristics: atmospheric turbidity, precipitable water and atmospheric ozone. The comparison between measured and predicted values have been successful. (author)

  14. Star-pointing spectrometer for measurements of atmospheric ozone

    Science.gov (United States)

    Oikarinen, Liisa; Saari, Heikki; Rainio, Kari; Graeffe, Jussi; Astola, Heikki

    1996-10-01

    Optical measurement of the density of ozone and other atmospheric species at night is possible by using stars as light sources. The Technical Research Centre of Finland (VTT) has built a star-pointing spectrometer, which records stellar spectra by a 2D CCD-array. The spectrometer has a 'slitless' design, so it can measure the absolute intensity level of a stellar spectrum attenuated by the atmosphere. A spectral inversion method designed for the satellite-based instrument GOMOS is applied for constituent retrieval form stellar spectra measured on ground. Analysis of simulated measurements shows that when averaging over one night the total ozone column can be measured by the VTT spectrometer at an accuracy of 2-3 percent.

  15. Estimate of the atmospheric turbidity from three broad-band solar radiation algorithms. A comparative study

    Directory of Open Access Journals (Sweden)

    G. López

    2004-09-01

    Full Text Available Atmospheric turbidity is an important parameter for assessing the air pollution in local areas, as well as being the main parameter controlling the attenuation of solar radiation reaching the Earth's surface under cloudless sky conditions. Among the different turbidity indices, the Ångström turbidity coefficient β is frequently used. In this work, we analyse the performance of three methods based on broad-band solar irradiance measurements in the estimation of β. The evaluation of the performance of the models was undertaken by graphical and statistical (root mean square errors and mean bias errors means. The data sets used in this study comprise measurements of broad-band solar irradiance obtained at eight radiometric stations and aerosol optical thickness measurements obtained at one co-located radiometric station. Since all three methods require estimates of precipitable water content, three common methods for calculating atmospheric precipitable water content from surface air temperature and relative humidity are evaluated. Results show that these methods exhibit significant differences for low values of precipitable water. The effect of these differences in precipitable water estimates on turbidity algorithms is discussed. Differences in hourly turbidity estimates are later examined. The effects of random errors in pyranometer measurements and cloud interferences on the performance of the models are also presented. Examination of the annual cycle of monthly mean values of β for each location has shown that all three turbidity algorithms are suitable for analysing long-term trends and seasonal patterns.

  16. Atmospheric Measurements by the Geoscience Laser Altimeter System: Initial Results

    Science.gov (United States)

    Spinhirne, J. D.; Palm, S. P.; Hlavka, D. L.; Hart, W. D.; Mahesh, A.; Welton, E. J.

    2003-01-01

    The Geoscience Laser Altimeter System launched in early 2003 is the first satellite instrument in space to globally observe the distribution of clouds and aerosol through laser remote sensing. The instrument is a basic backscatter lidar that operates at two wavelengths, 532 and 1064 nm. The mission data products for atmospheric observations include the calibrated, observed, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data is expected to significantly enhance knowledge in several areas of atmospheric science, in particular the distribution, transport and influence of atmospheric aerosol. Measurements of the coverage and height of polar and cirrus cloud should be significantly more accurate than previous global measurement. Initial result from the first several months of operation will be presented.

  17. Stable isotope measurement techniques for atmospheric greenhouse gases

    International Nuclear Information System (INIS)

    The technical requirements to perform useful measurements of atmospheric greenhouse gas concentrations and of their isotope ratios are of direct relevance for all laboratories engaged in this field. A meaningful interpretation of isotopes in global models on sources and sinks of CO2 and other greenhouse gases depends on strict laboratory protocols and data quality control measures ensuring comparable data in time and space. Only with this precondition met, the isotope techniques can serve as a potentially powerful method for reducing uncertainties in the global CO2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. This publication provides four contributions describing methods for the determination of the isotopic composition of trace gases in atmospheric air and in ice cores. These contributions have been indexed separately

  18. Further considerations of cosmic ray modulation of infra-red radiation in the atmosphere

    OpenAIRE

    Aplin, Karen; Lockwood, Mike

    2015-01-01

    Understanding effects of ionisation in the lower atmosphere is a new interdisciplinary area, crossing traditionally distinct scientific boundaries. Following the paper of Erlykin et al. (Astropart. Phys. 57--58 (2014) 26--29) we develop the interpretation of observed changes in long-wave (LW) radiation (Aplin and Lockwood, Env. Res. Letts. 8, 015026 (2013)), by taking account of cosmic ray ionisation yields and atmospheric radiative transfer. To demonstrate this, we show that the thermal stru...

  19. Atmospheric aerosol characterization combining multi-wavelength Raman lidar and MAX-DOAS measurements in Gwanjgu

    Science.gov (United States)

    Chong, Jihyo; Shin, Dong Ho; Kim, Kwang Chul; Lee, Kwon-Ho; Shin, Sungkyun; Noh, Young M.; Müller, Detlef; Kim, Young J.

    2011-11-01

    Integrated approach has been adopted at the ADvanced Environmental Research Center (ADEMRC), Gwangju Institute of Science and Technology (GIST), Korea for effective monitoring of atmospheric aerosol. Various active and passive optical remote sensing techniques such as multi-wavelength (3β+2α+1δ) Raman LIDAR, sun-photometry, MAX-DOAS, and satellite retrieval have been utilized. This integrated monitoring system approach combined with in-situ surface measurement is to allow better characterization of physical and optical properties of atmospheric aerosol. Information on the vertical distribution and microphysical properties of atmospheric aerosol is important for understanding its transport characteristics as well as radiative effect. The GIST multi-wavelength (3β + 2α+1δ) Raman lidar system can measure vertical profiles of optical properties of atmospheric aerosols such as extinction coefficients at 355 and 532nm, particle backscatter coefficients at 355, 532 and 1064 nm, and depolarization ratio at 532nm. The incomplete overlap between the telescope field-of-view and beam divergence of the transmitting laser significantly affects lidar measurement, resulting in higher uncertainty near the surface where atmospheric aerosols of interest are concentrated. Differential Optical Absorption Spectroscopy (DOAS) technique is applied as a complementary tool for the detection of atmospheric aerosols near the surface. The passive Multi-Axis DOAS (MAX-DOAS) technique uses scattered sunlight as a light source from several viewing directions. Recently developed aerosol retrieval algorithm based on O4 slant column densities (SCDs) measured at UV and visible wavelengths has been utilized to derive aerosol information (e.g., aerosol optical depth (AOD) and aerosol extinction coefficients (AECs)) in the lower troposphere. The aerosol extinction coefficient at 356 nm was retrieved for the 0-1 and 1-2 km layers based on the MAX-DOAS measurements using the retrieval algorithm

  20. Some questions about the Venus atmosphere from past measurements

    Science.gov (United States)

    Limaye, Sanjay

    2015-11-01

    The many missions undertaken in the past half a century to explore Venus with fly-by spacecraft, orbiters, descending probes, landers and floating balloons, have provided us with a wealth of data. These data have been supplemented by many ground based observations at reflected solar wavelengths, short and long wave infrared to radio waves. Inter-comparison of the results from such measurements provide a good general idea of the global atmosphere. However, re-visiting these observations also raises some questions about the atmosphere that have not received much attention lately but deserve to be explored and considered for future measurements.These questions are about the precise atmospheric composition in the deep atmosphere, the atmospheric state in the lower atmosphere, the static stability of the lower atmosphere, the clouds and hazes, the nature of the ultraviolet absorber and wind speed and direction near the surface from equator to the pole. The answers to these questions are important for a better understanding of Venus, its weather and climate. The measurements required to answer these questions require careful and sustained observations within the atmosphere and from surface based stations. Some of these measurements should and can be made by large missions such as Venera-D (Russia), Venus Climate Mission (Visions and Voyages - Planetary Science Decadal Survey 2013-2022 or the Venus Flagship Design Reference Mission (NASA) which have been studied in recent years, but some have not been addressed in such studies. For example, the fact that the two primary constituents of the Venus atmosphere - Carbon Dioxide and Nitrogen are supercritical has not been considered so far. It is only recently that properties of binary supercritical fluids are being studied theoretically and laboratory validation is needed.With the end of monitoring of Venus by Venus Express orbiter in November 2014 after nearly a decade of observations and the imminent insertion of JAXA

  1. Automatic actinometric system for diffuse radiation measurement

    Science.gov (United States)

    Litwiniuk, Agnieszka; Zajkowski, Maciej

    2015-09-01

    Actinometric station is using for measuring solar of radiation. The results are helpful in determining the optimal position of solar panels relative to the Sun, especially in today's world, when the energy coming from the Sun and other alternative sources of energy become more and more popular. Polish climate does not provide as much energy as in countries in southern Europe, but it is possible to increase the amount of energy produced by appropriate arrangement of photovoltaic panels. There is the possibility of forecasting the amount of produced energy, the cost-effectiveness and profitability of photovoltaic installations. This implies considerable development opportunities for domestic photovoltaic power plants. This article presents description of actinometric system for diffuse radiation measurement, which is equipped with pyranometer - thermopile temperature sensor, amplifier AD620, AD Converter ADS1110, microcontroller Atmega 16, SD card, GPS module and LCD screen.

  2. Vector radiative transfer numerical model of coupled ocean-atmosphere system using matrix-operator method

    Institute of Scientific and Technical Information of China (English)

    HE XianQiang; PAN DeLu; BAI Yan; ZHU QianKun; GONG Fang

    2007-01-01

    A vector radiative transfer numerical model of the coupled ocean-atmosphere system is developed based on the matrix-operator method,which is named PCOART.Using the Fourier analysis,the vector radiative transfer equation (VRTE) is separated into a set of equations depending only on the observation zenith angle.Using the Gaussian-Quadrature method,VRTE is finally transferred into the matrix equation solved by the adding-doubling method.According to the reflective and refractive properties of the ocean-atmosphere interface,the vector radiative transfer numerical model of the ocean and atmosphere is coupled in PCOART.Compared with the exact Rayleigh scattering look-up tables of MODIS (Moderate-resolution Imaging Spectroradiometer),it is shown that PCOART is an exactly numerical model,and the processing methods of the multi-scattering and polarization are correct.Also,validated with the standard problems of the radiative transfer in water,it is shown that PCOART can be used to calculate the underwater radiative transfer problems.Therefore,PCOART is a useful tool for exactly calculating the vector radiative transfer of the coupled ocean-atmosphere system,which can be used to study the polarization properties of the radiance in the whole ocean-atmosphere system and the remote sensing of the atmosphere and ocean.

  3. Vector radiative transfer numerical model of coupled ocean-atmosphere system using matrix-operator method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A vector radiative transfer numerical model of the coupled ocean-atmosphere system is developed based on the matrix-operator method, which is named PCOART. Using the Fourier analysis, the vector radiative transfer equation (VRTE) is separated into a set of equations depending only on the observa-tion zenith angle. Using the Gaussian-Quadrature method, VRTE is finally transferred into the matrix equation solved by the adding-doubling method. According to the reflective and refractive properties of the ocean-atmosphere interface, the vector radiative transfer numerical model of the ocean and at-mosphere is coupled in PCOART. Compared with the exact Rayleigh scattering look-up tables of MODIS (Moderate-resolution Imaging Spectroradiometer), it is shown that PCOART is an exactly numerical model, and the processing methods of the multi-scattering and polarization are correct. Also, validated with the standard problems of the radiative transfer in water, it is shown that PCOART can be used to calculate the underwater radiative transfer problems. Therefore, PCOART is a useful tool for exactly calculating the vector radiative transfer of the coupled ocean-atmosphere system, which can be used to study the polarization properties of the radiance in the whole ocean-atmosphere system and the remote sensing of the atmosphere and ocean.

  4. Marine radiation measured with personal dosimeter

    International Nuclear Information System (INIS)

    This measurement was conducted after the Fukushima Daiichi Nuclear Power Plant Accident to study preliminarily the influence of the Accident on the sea water radiation and to get the information like materials and methods to measure the marine radiation for coming authorized study. The integrating dosimeters used were for personal fitting, Aloka's MYDOSEminiE PDM-111 with the silicon P-N junction semiconductor detector and ECOTEST's TERRA MKS-05, a GM tube type. Measurement was done with PDM-111 placed in a water-resistant vessel set up at 1 m and 3 cm distances from the bottom at the maximal depth of 100 m of 10 sea spots in Kochi Prefecture. Radiation doses were found to be 0.04-0.07 mcSv/h at the bottom of 6-13 m depth, which varied with the configuration of the bed, and 0.03 mcSv/h in water at either depth of the average 16 m or at 1 m far from the bottom. The dose rates in water and at bottom were found to decrease with increase of the depth by the enough long time measurement at 25 m and 40 m. Further, the more distant from the land, the lower the rates: 0.03-0.04 mcSv/h, which was thought to be derived from the cosmic ray. Results with MKS-05 were found to be of similar tendency to those by PDM-111 above and to be less sensitive. Authorized studies on marine radiation should be conducted systematically within a nearest future. (T.T.)

  5. MAX-DOAS measurements of atmospheric trace gases in Ny-Ålesund

    Science.gov (United States)

    Wittrock, F.; Oetjen, H.; Richter, A.; Fietkau, S.; Medeke, T.; Rozanov, A.; Burrows, J. P.

    2003-12-01

    A new approach to derive tropospheric concentrations of some atmospheric trace gases from ground-based UV/vis measurements is described. The instrument, referred to as the MAX-DOAS, is based on the well-known UV/vis instruments, which use the sunlight scattered in the zenith sky as the light source and the method of Differential Optical Absorption Spectroscopy (DOAS) to derive column amounts of absorbers like ozone and nitrogen dioxide. Substantial enhancements have been applied to this standard setup to use different lines of sight near to the horizon as additional light sources (MAX - multi axis). Results from measurements at Ny-Ålesund (79° N, 12° E) are presented and interpreted with the full-spherical radiation transport model SCIATRAN. In particular, measurements of the oxygen dimer O4 which has a known column and vertical distribution in the atmosphere are used to evaluate the sensitivity of the retrieval to parameters such as multiple scattering, solar azimuth, surface albedo and refraction in the atmosphere and also to validate the radiative transport model. As a first application, measurements of NO2 emissions from a ship lying in Ny-Ålesund harbour are presented. The results of this study demonstrate the feasibility of long term UV/vis multi axis measurement that can be used to derive not only column amounts of different trace gases but also some information on the vertical location of these absorbers.

  6. The emittance of space radiator materials measured at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Mirtich, M.J. [Lewis Research Center, Cleveland, OH (United States); DiFilippo, F. [Case Western Reserve Univ., Cleveland, OH (United States); Barry, J.; Kussmaul, M. [Cleveland State Univ., OH (United States)

    1994-09-01

    The spectral emittances of textured space radiator materials between 1.7 and 14.7 {mu}m have been evaluated at room temperature and elevated temperature (630{degrees}C) in air. Heating in air caused a permanent increase in spectral emittance for all materials tested: HCl/ion beam textured 304 stainless steel, untextured Ti (6 percent Al, 4 percent V), and sandblasted Ti (6 percent Al, 4 percent V). Changes in the surface chemistry and/or surface morphology of these materials were also observed. Elevated temperature spectral emittance was measured in an argon atmosphere and compared to the measurements in air. Similarity between the room temperature and elevated temperature spectral emittance measurements was also investigated, and limited agreement was found.

  7. Greenhouse gases regional fluxes estimated from atmospheric measurements

    International Nuclear Information System (INIS)

    build up a new system to measure continuously CO2 (or CO), CH4, N2O and SF6 mixing ratios. It is based on a commercial gas chromatograph (Agilent 6890N) which have been modified to reach better precision. Reproducibility computed with a target gas on a 24 hours time step gives: 0.06 ppm for CO2, 1.4 ppb for CO, 0.7 ppb for CH4, 0.2 ppb for N2O and 0.05 ppt for SF6. The instrument's run is fully automated, an air sample analysis takes about 5 minutes. In July 2006, I install instrumentation on a telecommunication tall tower (200 m) situated near Orleans forest in Trainou, to monitor continuously greenhouse gases (CO2, CH4, N2O, SF6), atmospheric tracers (CO, Radon-222) and meteorological parameters. Intake lines were installed at 3 levels (50, 100 and 180 m) and allow us to sample air masses along the vertical. Continuous measurement started in January 2007. I used Mace Head (Ireland) and Gif-sur-Yvette continuous measurements to estimate major greenhouse gases emission fluxes at regional scale. To make the link between atmospheric measurements and surface fluxes, we need to quantify dilution due to atmospheric transport. I used Radon-222 as tracer (radon tracer method) and planetary boundary layer heights estimates from ECMWF model (boundary layer budget method) to parameterize atmospheric transport. In both cases I compared results to available emission inventories. (author)

  8. Determination of atmospheric aerosol properties over land using satellite measurements

    NARCIS (Netherlands)

    Kokhanovsky, A.A.; Leeuw, G. de

    2009-01-01

    Mostly, aerosol properties are poorly understood because the aerosol properties are very sparse. The first workshop on the determination of atmospheric aerosol properties over land using satellite measurements is convened in Bremen, Germany. In this workshop, the topics of discussions included a var

  9. Development of prototype fiber optics dosimeter for remote radiation measurements

    International Nuclear Information System (INIS)

    Optical fiber dosimetry has been studied as an emerging method of monitoring radiation remotely in difficult to access and hazardous areas and is suitable for use in confined environments that may be inaccessible using existing dosimeters. Being light weight and non intrusive, optical fibers provide several advantages in the field of dosimetry like resistant to electromagnetic interferences. An extrinsic architecture, where the radiation-sensing component is spliced or coupled to an optical fiber, is employed in this work. A prototype single channel fiber optic based remote radiation measurement system with BaFBr:Eu sensor, which has a wide linear dose response, is developed at Radiological Safety Division, IGCAR. High sensitive BaFBr:Eu2+ storage phosphor of 10 mm dia and 4 mm thickness has been successfully synthesized using high temperature solid state diffusion route in a reducing atmosphere. Optical characteristics of the BaFBr:Eu pellet were studied by taking Photoluminescence (PL) and Photo stimulated luminescence (PSL) measurements. PL emission wavelength is measured to be 390 nm. The BaFBr:Eu is irradiated for various absorbed doses in a gamma chamber at 213 Gy/hr using 60Co standard source (BRIT make) available at RSD, IGCAR

  10. Estimations of climate sensitivity based on top-of-atmosphere radiation imbalance

    Directory of Open Access Journals (Sweden)

    B. Lin

    2010-02-01

    Full Text Available Large climate feedback uncertainties limit the accuracy in predicting the response of the Earth's climate to the increase of CO2 concentration within the atmosphere. This study explores a potential to reduce uncertainties in climate sensitivity estimations using energy balance analysis, especially top-of-atmosphere (TOA radiation imbalance. The time-scales studied generally cover from decade to century, that is, middle-range climate sensitivity is considered, which is directly related to the climate issue caused by atmospheric CO2 change. The significant difference between current analysis and previous energy balance models is that the current study targets at the boundary condition problem instead of solving the initial condition problem. Additionally, climate system memory and deep ocean heat transport are considered. The climate feedbacks are obtained based on the constraints of the TOA radiation imbalance and surface temperature measurements of the present climate. In this study, the TOA imbalance value of 0.85 W/m2 is used. Note that this imbalance value has large uncertainties. Based on this value, a positive climate feedback with a feedback coefficient ranging from −1.3 to −1.0 W/m2/K is found. The range of feedback coefficient is determined by climate system memory. The longer the memory, the stronger the positive feedback. The estimated time constant of the climate is large (70~120 years mainly owing to the deep ocean heat transport, implying that the system may be not in an equilibrium state under the external forcing during the industrial era. For the doubled-CO2 climate (or 3.7 W/m2 forcing, the estimated global warming would be 3.1 K if the current estimate of 0.85 W/m2 TOA net radiative heating could be confirmed. With accurate long-term measurements of TOA radiation, the analysis method suggested by this study provides a great potential in the

  11. Vertical profiles of BC direct radiative effect over Italy: high vertical resolution data and atmospheric feedbacks

    Science.gov (United States)

    Močnik, Griša; Ferrero, Luca; Castelli, Mariapina; Ferrini, Barbara S.; Moscatelli, Marco; Grazia Perrone, Maria; Sangiorgi, Giorgia; Rovelli, Grazia; D'Angelo, Luca; Moroni, Beatrice; Scardazza, Francesco; Bolzacchini, Ezio; Petitta, Marcello; Cappelletti, David

    2016-04-01

    Black carbon (BC), and its vertical distribution, affects the climate. Global measurements of BC vertical profiles are lacking to support climate change research. To fill this gap, a campaign was conducted over three Italian basin valleys, Terni Valley (Appennines), Po Valley and Passiria Valley (Alps), to characterize the impact of BC on the radiative budget under similar orographic conditions. 120 vertical profiles were measured in winter 2010. The BC vertical profiles, together with aerosol size distribution, aerosol chemistry and meteorological parameters, have been determined using a tethered balloon-based platform equipped with: a micro-Aethalometer AE51 (Magee Scientific), a 1.107 Grimm OPC (0.25-32 μm, 31 size classes), a cascade impactor (Siuotas SKC), and a meteorological station (LSI-Lastem). The aerosol chemical composition was determined from collected PM2.5 samples. The aerosol absorption along the vertical profiles was measured and optical properties calculated using the Mie theory applied to the aerosol size distribution. The aerosol optical properties were validated with AERONET data and then used as inputs to the radiative transfer model libRadtran. Vertical profiles of the aerosol direct radiative effect, the related atmospheric absorption and the heating rate were calculated. Vertical profile measurements revealed some common behaviors over the studied basin valleys. From below the mixing height to above it, a marked concentration drop was found for both BC (from -48.4±5.3% up to -69.1±5.5%) and aerosol number concentration (from -23.9±4.3% up to -46.5±7.3%). These features reflected on the optical properties of the aerosol. Absorption and scattering coefficients decreased from below the MH to above it (babs from -47.6±2.5% up to -71.3±3.0% and bsca from -23.5±0.8% up to -61.2±3.1%, respectively). Consequently, the Single Scattering Albedo increased above the MH (from +4.9±2.2% to +7.4±1.0%). The highest aerosol absorption was

  12. Web based Measurement System for Solar Radiation

    Directory of Open Access Journals (Sweden)

    Shachi Awasthi

    2012-06-01

    Full Text Available We present in this paper, the principles of themeasurement system for solar radiation, and ourimplementation using Web based data loggingconcept.The photocurrent produced by Silicon PNjunction is used as a solar radiation transducer, tomake it more viable we have used commerciallyavailable solar panels as our transducers. Using asilicon solar cell as sensor, a low cost solarradiometer can be constructed. The photocurrentproduced by solar cell is electronically tailored to bemeasured and stored by our web based dataacquisition and monitoring system. Measurementusing real solar cell array gives a good measure ofactual producible energy by solar arrays. Ourportable instrument can be used in remote sites andsubstitutes the solar monitor and integrator,Current data of solar radiation can be monitoredusing Ethernet interface available in all PC,Laptops. We store the data into a secure digital cardwhich can be retrieved to plot and analyse the data.We have developed system hardware andsoftware based on ATmega32 AVR Microcontrollersand ENC28J60 Ethernet PHY and MAC networkinterface chip by Microchip.So the global irradiance data are obtained aftercorrection using the instantaneous measurement ofambient temperature which allows us to calculatethe junction temperature and consequently improvethe precision of measurement of our dataacquisition system

  13. Mobile Atmospheric Aerosol and Radiation Characterization Observatory (MAARCO)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: MAARCO is designed as a stand-alone facility for basic atmospheric research and the collection of data to assist in validating aerosol and weather models....

  14. Study and measurement of the atmospheric pollution by 85Kr

    International Nuclear Information System (INIS)

    Because of the importance of eventual long term radiological and synergistic effects of 85Kr pollution from the nuclear energy industry the atmospheric activity was followed and laboratory experiments on the initiation of eventual climatological effects were developed. An EPA method for separating krypton from air and for measuring the radioactivity was applied. The modified experimental set-up for collection, separation and measurement is illustrated. The total collection and separation efficiency is about 55%. The efficiency of the nuclear β-measurement was found to be 72% using a calibrated source. The results of periodic atmospheric measurements in Ghent during 1979 are reported. Comparative calculations based on available source terms are presented. (H.K.)

  15. SURFRAD-A National Surface Radiation Budget Network for Atmospheric Research.

    Science.gov (United States)

    Augustine, John A.; Deluisi, John J.; Long, Charles N.

    2000-10-01

    A surface radiation budget observing network (SURFRAD) has been established for the United States to support satellite retrieval validation, modeling, and climate, hydrology, and weather research. The primary measurements are the downwelling and upwelling components of broadband solar and thermal infrared irradiance. A hallmark of the network is the measurement and computation of ancillary parameters important to the transmission of radiation. SURFRAD commenced operation in 1995. Presently, it is made up of six stations in diverse climates, including the moist subtropical environment of the U.S. southeast, the cool and dry northern plains, and the hot and arid desert southwest. Network operation involves a rigorous regimen of frequent calibration, quality assurance, and data quality control. An efficient supporting infrastructure has been created to gather, check, and disseminate the basic data expeditiously. Quality controlled daily processed data files from each station are usually available via the Internet within a day of real time. Data from SURFRAD have been used to validate measurements from NASA's Earth Observing System series of satellites, satellite-based retrievals of surface erythematogenic radiation, the national ultraviolet index, and real-time National Environmental Satellite, Data, and Information Service (NESDIS) products. It has also been used for carbon sequestration studies, to check radiative transfer codes in various physical models, for basic research and instruction at universities, climate research, and for many other applications. Two stations now have atmospheric energy flux and soil heat flux instrumentation, making them full surface energy balance sites. It is hoped that eventually all SURFRAD stations will have this capability.

  16. A New Laser Based Approach for Measuring Atmospheric Greenhouse Gases

    OpenAIRE

    2013-01-01

    In 2012, we developed a proof-of-concept system for a new open-path laser absorption spectrometer concept for measuring atmospheric CO2. The measurement approach utilizes high-reliability all-fiber-based, continuous-wave laser technology, along with a unique all-digital lock-in amplifier method that, together, enables simultaneous transmission and reception of multiple fixed wavelengths of light. This new technique, which utilizes very little transmitted energy relative to conventional lidar ...

  17. Radiation exposure measurement onboard civil aircraft

    International Nuclear Information System (INIS)

    The active dosemeter DOSTEL based on two silicon planar detectors was flown on civil aircraft flights to study the radiation exposure of air crew members. The altitude and latitude dependence of count and dose rates as well as long-term variations are measured. After calibration of the DOSTEL response against measurements of a TEPC instrument, total dose-equivalent values for various flights are compared with H*(10) calculations by EPCARD yielding a ratio of 1.02 ± 0.09 (standard variation). (authors)

  18. Final Report - From Measurements to Models: Cross-Comparison of Measured and Simulated Behavioral States of the Atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Del Genio, Anthony D; Hoffman, Forrest M; Hargrove, Jr, William W

    2007-10-22

    The ARM sites and the ARM Mobile Facility (AMF) were constructed to make measurements of the atmosphere and radiation system in order to quantify deficiencies in the simulation of clouds within models and to make improvements in those models. While the measurement infrastructure of ARM is well-developed and a model parameterization testbed capability has been established, additional effort is needed to develop statistical techniques which permit the comparison of simulation output from atmospheric models with actual measurements. Our project establishes a new methodology for objectively comparing ARM measurements to the outputs of leading global climate models and reanalysis data. The quantitative basis for this comparison is provided by a statistical procedure which establishes an exhaustive set of mutually-exclusive, recurring states of the atmosphere from sets of multivariate atmospheric and cloud conditions, and then classifies multivariate measurements or simulation outputs into those states. Whether measurements and models classify the atmosphere into the same states at specific locations through time provides an unequivocal comparison result. Times and locations in both geographic and state space of model-measurement agreement and disagreement will suggest directions for the collection of additional measurements at existing sites, provide insight into the global representativeness of the current ARM sites (suggesting locations and times for use of the AMF), and provide a basis for improvement of models. Two different analyses were conducted: One, using the Parallel Climate Model, focused on an IPCC climate change scenario and clusters that characterize long-term changes in the hydrologic cycle. The other, using the GISS Model E GCM and the ARM Active Remotely Sensed Cloud Layers product, explored current climate cloud regimes in the Tropical West Pacific.

  19. Advanced angular interpolation in the vector radiative transfer for coupled atmosphere and ocean systems

    International Nuclear Information System (INIS)

    We apply the iteration of source function (IOSF) philosophy to the successive order of scattering method for solving the vector radiative transfer equation in the coupled atmosphere and ocean system. A major class of radiative transfer solvers only provides the radiation field at discrete viewing zenith angles. The radiation field at other angles is found by interpolation. The iteration of source matrix method integrates the product of the radiation field and source matrix at quadrature points to obtain the radiation field at arbitrary viewing angles. The resultant solution includes the radiation contributions from all scattering orders higher than one. The analytical single scattering solution is then added to find the total radiation field. The proposed scheme includes the benefits of both the IOSF interpolation and the analytical single scattering solution. Boundary conditions for a flat air–sea interface are fully considered. A test case of a coupled atmosphere and ocean system shows that this combined method improves the polarized radiation field greatly in comparison with the regular polynomial interpolation method. -- Highlights: ► The iteration of source matrix method is applied to vector radiative transfer. ► The Stokes parameters at arbitrary viewing angles are obtained. ► Special focus is on coupled atmosphere and ocean systems. ► The analytical single scattering solution is used to increase accuracy.

  20. Atmospheric mercury measurements onboard the CARIBIC passenger aircraft

    Science.gov (United States)

    Slemr, Franz; Weigelt, Andreas; Ebinghaus, Ralf; Kock, Hans H.; Bödewadt, Jan; Brenninkmeijer, Carl A. M.; Rauthe-Schöch, Armin; Weber, Stefan; Hermann, Markus; Becker, Julia; Zahn, Andreas; Martinsson, Bengt

    2016-05-01

    Goal of the project CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrumented Container) is to carry out regular and detailed observations of atmospheric composition (particles and gases) at cruising altitudes of passenger aircraft, i.e. at 9-12 km. Mercury has been measured since May 2005 by a modified Tekran instrument (Tekran Model 2537 A analyser, Tekran Inc., Toronto, Canada) during monthly intercontinental flights between Europe and South and North America, Africa, and Asia. Here we describe the instrument modifications, the post-flight processing of the raw instrument signal, and the fractionation experiments.

  1. Upconversion-based lidar measurements of atmospheric CO2

    DEFF Research Database (Denmark)

    Høgstedt, Lasse; Fix, Andreas; Wirth, Martin;

    2016-01-01

    For the first time an upconversion based detection scheme is demonstrated for lidar measurements of atmospheric CO2-concentrations, with a hard target at a range of 3 km and atmospheric backscatter from a range of similar to 450 m. The pulsed signals at 1572 nm are upconverted to 635 nm, and dete...... analyzed how the field-of-view of a receiver system, for long range detection, depends critically on the parameters for the nonlinear upconversion process, and how to optimize these parameters in future systems. (C) 2016 Optical Society of America...

  2. Water vapor measurement system in global atmospheric sampling program, appendix

    Science.gov (United States)

    Englund, D. R.; Dudzinski, T. J.

    1982-01-01

    The water vapor measurement system used in the NASA Global Atmospheric Sampling Program (GASP) is described. The system used a modified version of a commercially available dew/frostpoint hygrometer with a thermoelectrically cooled mirror sensor. The modifications extended the range of the hygrometer to enable air sample measurements with frostpoint temperatures down to -80 C at altitudes of 6 to 13 km. Other modifications were made to permit automatic, unattended operation in an aircraft environment. This report described the hygrometer, its integration with the GASP system, its calibration, and operational aspects including measurement errors. The estimated uncertainty of the dew/frostpoint measurements was + or - 1.7 Celsius.

  3. A toy model linking atmospheric thermal radiation and sea ice growth

    Science.gov (United States)

    Thorndike, A. S.

    1992-01-01

    A simplified analytical model of sea ice growth is presented where the atmosphere is in thermal radiative equilibrium with the ice. This makes the downwelling longwave radiation reaching the ice surface an internal variable rather than a specified forcing. Analytical results demonstrate how the ice state depends on properties of the ice and on the externally specified climate.

  4. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-05-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 s. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  5. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-01-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 seconds. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  6. Fractional integration and radiative transfer in a multifractal atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Naud, C.; Schertzer, D. [Universite Pierre et Marie Curie, Paris (France); Lovejoy, S. [McGill Univ., Montreal (Canada)

    1996-04-01

    Recently, Cess et al. (1995) and Ramathan et al. (1995) cited observations which exhibit an anomalous absorption of cloudy skies in comparison with the value predicted by usual models and which thus introduce large uncertainties for climatic change assessments. These observation raise questions concerning the way general circulation models have been tuned for decades, relying on classical methods, of both radiative transfer and dynamical modeling. The observations also tend to demonstrate that homogeneous models are simply not relevant in relating the highly variable properties of clouds and radiation fields. However smoothed, the intensity of cloud`s multi-scattered radiation fields reflect this extreme variability.

  7. Measurement of the dynamic characteristics of atmospheric diffusion

    International Nuclear Information System (INIS)

    A new method is proposed for studying the diffusion of atmospheric pollutants above real sites which considers the actual magnitudes encountered. The dynamic application of this method yields original information. In view of justifying the method, fundamental theories concerning diffusion are presented together with different models for the atmosphere. The atmosphere is then considered as a linear filter to which the process identification method is applied. The pulse response of the filter is examined in the pollutant - time plane. The limits of the method and its field of application are discussed. The concept of ergodism and stationariness are introduced. Various diffusion experiments carried out under different conditions are reviewed. Information on the effect of obstacles, and the roughness of the ground is given together with calculations of the longitudinal diffusion and the transport velocity. A brief description is then given of the apparatus used to measure the concentrations and the meteorological conditions. The correlation calculation is also briefly presented. (author)

  8. Atmospheric stability and complex terrain: comparing measurements and CFD

    DEFF Research Database (Denmark)

    Koblitz, Tilman; Bechmann, Andreas; Berg, Jacob;

    2014-01-01

    , buoyancy forces and heat transport, are mostly ignored in state-of-the-art flow solvers. In order to decrease the uncertainty of wind resource assessment, the effect of thermal stratification on the atmospheric boundary layer should be included in such models. The present work focuses on non......-neutral atmospheric flow over complex terrain including physical processes like stability and Coriolis force. We examine the influence of these effects on the whole atmospheric boundary layer using the DTU Wind Energy flow solver EllipSys3D. To validate the flow solver, measurements from Benakanahalli hill, a field...... experiment that took place in India in early 2010, are used. The experiment was specifically designed to address the combined effects of stability and Coriolis force over complex terrain, and provides a dataset to validate flow solvers. Including those effects into EllipSys3D significantly improves the...

  9. Long path DOAS measurements of atmospheric pollutants concentration

    Science.gov (United States)

    Geiko, Pavel P.; Smirnov, Sergey S.; Samokhvalov, Ignatii V.

    2015-11-01

    A differential optical absorption spectroscopy gas-analyzer consisted of a coaxial telescope, a spectrometer, an analyzer and retroreflector was successfully tested. A high pressure 150-W Xe arc lamp was employed as a light source. In order to record the spectra, a monochrometer with a grating and photodiode array was used. Gas analyzer spectral data bank includes more than 35 moleculas absorbed in UV spectral region. The measured absorption spectra were evaluated by using a least-squares fit to determine the average mixing ratio of each species in the atmosphere. As a result of experiments time series of concentrations of gases polluting the atmosphere were trace measured. Minimally detected concentration on pathlength 480 m is the unit of ppb at the time of accumulation of 2 min. The results of the field test measurements of pollutants in Tomsk city are presented.

  10. Measurement of the atmospheric primary aberrations by 4-aperture DIMM

    CERN Document Server

    Shomali, Ramin; Darudi, Ahmad

    2011-01-01

    The present paper investigates and discusses the ability of the Hartmann test with 4-aperture DIMM to measure the atmospheric primary aberrations which, in turn, can be used for calculation of the atmospheric coherence time. Through performing numerical simulations, we show that the 4-aperture DIMM is able to measure the defocus and astigmatism terms correctly while its results are not reliable for the coma. The most important limitation in the measurement of the primary aberrations by 4-aperture DIMM is the centroid displacements of the spots which are caused by the higher order aberrations. This effect is negligible in calculating of the defocus and astigmatisms, while, it cannot be ignored in the calculation of the coma.

  11. Measurement of Thermal Radiation Properties of Solids

    Science.gov (United States)

    Richmond, J. C. (Editor)

    1963-01-01

    The overall objectives of the Symposium were to afford (1) an opportunity for workers in the field to describe the equipment and procedures currently in use for measuring thermal radiation properties of solids, (2) an opportunity for constructive criticism of the material presented, and (3) an open forum for discussion of mutual problems. It was also the hope of the sponsors that the published proceedings of the Symposium would serve as a valuable reference on measurement techniques for evaluating thermal radiation properties of solids, partic.ularly for those with limited experience in the field. Because of the strong dependence of emitted flux upon temperature, the program committee thought it advisable to devote the first session to a discussion of the problems of temperature measurement. All of the papers in Session I were presented at the request of and upon topics suggested by the Committee. Because of time and space limitations, it, was impossible to consider all temperature measurement problems that might arise--the objective was rather to call to the attention of the reader some of the problems that might be encountered, and to provide references that might provide solutions.

  12. Urban-rural solar radiation loss in the atmosphere of Greater Cairo region, Egypt

    International Nuclear Information System (INIS)

    A comparative study for measured global solar radiation, G, during the period (1969-2006) and the corresponding global radiation loss in the atmosphere, RL%, over urban and rural districts in Greater Cairo region have been performed. The climatic variabilities of G radiation at the urban and rural sites are also investigated and discussed. Monthly, seasonal and annual mean values of extraterrestrial radiation, Go, and RL% during four successive periods, (1969-1978), (1979-1988), (1989-1998) and (1999-2006) at the above two sites have been calculated and investigated. The results revealed that urban area was always received lower amount of solar radiation due to urbanization factors. The yearly mean values of G radiation were distinctly decreased from maximum value 21.93 and 22.62 MJ m-2 during 1970 year to minimum value 17.57 and 17.87 MJ m-2 during 2004 and 2006 years with average decrease rate 0.09 and 0.10 MJ m-2 per year for the urban and rural areas, respectively. Also, the seasonal and annual mean anomalies of G radiation have been also gradually decreased from maximum values during the eldest period (1969-1978) to minimum values during the recent period (1999-2006). RL% over the urban area was always higher than that rural area. The urban-rural RL% differences range from 0.61% in 1999 year to 4.19% in 2002 year and 2.20% as average value. The yearly mean of RL% values distinctly gradually increase from minimum value 29.47% and 27.28% during 1970 year to maximum value 43.50% and 42.60% during 2004 and 2006 years with average increase rate 0.28% and 0.32% per year for the urban and rural areas, respectively. The minimum value of RL% (26.88%) occurred at rural area during summer season of the eldest period (1969-1978) while the maximum value of RL% (51.27%) occurred at the urban area during winter season of the last recent urbanized period (1999-2006). The linear trend of the yearly variations of RL% revealed that G values will reach zero over the urban and

  13. Multi-functional combustible gas measurement of containment atmosphere

    International Nuclear Information System (INIS)

    During severe accidents large amounts of hydrogen can be released inside the reactor containment and can leak to adjacent room areas. Without countermeasures these releases might lead to a significant combustible gas accumulation and an ignition of the gas mixture might exceed overpressure design values and jeopardize the integrity of the containment. For severe accident management actions and evaluation of the situation inside the containment, reliable information is needed on the current containment atmosphere mixture. This includes e.g. the content of gases as hydrogen, steam, oxygen or CO. Knowledge about the CO concentration might become essential for severe accident management as it is an indicator for the core localization. Hydrogen, steam, oxygen measurement is required for the assessment of the combustion regime and possible combustion modes (e.g. fast, slow deflagration, inert conditions). In order to allow a reliable measurement of the containment atmosphere AREVA GmbH has developed two monitoring systems called WS85 and HERMETIS. For pure hydrogen measurement the WS85 sensor system can be installed, e.g. at the fuel pool level or at different locations in containment. The signals of the sensor are passed through an accident proofed cable to a measuring electronic. The electronic provides signal amplification and conditioning for recording and displaying in the plant I and C. The measuring cell consists of a combined catalytic and thermal conductivity measuring principle. Furthermore, an integrated resistance thermometer detects the temperature of the surrounding sensor atmosphere. The newly developed upgrade of the sensor, called WS85-Plus, is able to determine the hydrogen concentration in a nitrogen inert containment atmosphere. Besides the hydrogen concentration determined by the WS85 sensor, the Multi-Functional Containment Atmosphere Monitoring System HERMETIS allows for a measurement of hydrogen, steam, oxygen as well as CO. In this case, a micro

  14. Conference on Atmospheric Radiation, 7th, San Francisco, CA, July 23-27, 1990, Preprints

    International Nuclear Information System (INIS)

    The present conference on atmospheric radiation discusses the Cirrus experiment, cloud climatologies, the earth radiation budget, the surface radiation budget, remote sensing, radiative transfer, arctic clouds and aerosols, and clouds and radiation. Attention is given to the results of the FIRE Marine Stratocumulus Observations, cirrus cloud properties derived from satellite radiances during FIRE, the dimension of a cloud's boundary, and satellite observations of cirrus clouds. Topics addressed include the seasonal variation of the diurnal cycles of the earth's radiation budget determined from ERBE, estimation of the outgoing longwave flux from NOAA AVHRR satellite observations, a comparison of observed and modeled longwave radiances, and climate monitoring using radiative entropy from ERB observations. Also discussed are approximations to the diffuse radiative properties of cloud layers, the greenhouse potential of other trace gases relative to CO2, global surface albedos estimated from ERBE data, and the energy exchange in a tropical rain forest

  15. Atmospheric Sulfur Hexafluoride: Measurements and Emission Estimates from 1970 - 2008

    Science.gov (United States)

    Rigby, M. L.; Prinn, R. G.; Muhle, J.; Miller, B. R.; Dlugokencky, E. J.; Krummel, P. B.; Steele, L. P.; Fraser, P. J.; Leist, M.; Weiss, R. F.; Harth, C. M.; O'Doherty, S. J.; Greally, B. R.; Simmonds, P. G.; Derek, N.; Vollmer, M. K.; Kim, J.; Kim, K.; Porter, L. W.

    2009-12-01

    We present an air history of atmospheric sulfur hexafluoride (SF6) from the early 1970s through 2008. During this period, concentrations of this extremely potent and long-lived greenhouse gas have increased by more than an order of magnitude, and its growth has accelerated in recent years. In this study, historical concentrations are determined from archived air samples measured on the Advanced Global Atmospheric Gases Experiment (AGAGE) ‘Medusa’ gas chromatography/mass spectrometry system. These data are combined with modern high-frequency measurements from the AGAGE and National Oceanic and Atmospheric Administration (NOAA) in situ networks and ˜weekly samples from the NOAA flask network, to produce a unique time series with increasing global coverage spanning almost four decades. Using the three-dimensional chemical transport Model for Ozone and Related Tracers (MOZART v4.5) and a discrete Kalman filter, we derive estimates of the annual emission strength of SF6 on hemispheric scales from 1970 - 2004 and on continental scales from 2004 - 2008. Our emission estimates are compared to the recently compiled Emissions Database for Global Atmospheric Research (EDGAR v4), and emissions reported under the United Nations Framework Convention on Climate Change (UNFCCC). The cause of the recent growth rate increase is also investigated, indicating that the origin of the required emissions rise is likely to be South-East Asia.

  16. Use of POES SEM-2 observations to examine radiation belt dynamics and energetic electron precipitation into the atmosphere

    OpenAIRE

    Rodger, Craig J.; Clilverd, Mark A.; Green, Janet C.; Lam, Mai Mai

    2010-01-01

    The coupling of the Van Allen radiation belts to the Earth's atmosphere through precipitating particles is an area of intense scientific interest. Currently, there are significant uncertainties surrounding the precipitating characteristics of medium energy electrons (> 20 keV), and even more uncertainties for relativistic electrons. In this paper we examine roughly 10 years of measurements of trapped and precipitating electrons available from the Polar Orbiting Environmental Satellites (POES)...

  17. Photocatalytic Active Radiation Measurements and Use

    Science.gov (United States)

    Davis, Bruce A.; Underwood, Lauren W.

    2011-01-01

    Photocatalytic materials are being used to purify air, to kill microbes, and to keep surfaces clean. A wide variety of materials are being developed, many of which have different abilities to absorb various wavelengths of light. Material variability, combined with both spectral illumination intensity and spectral distribution variability, will produce a wide range of performance results. The proposed technology estimates photocatalytic active radiation (PcAR), a unit of radiation that normalizes the amount of light based on its spectral distribution and on the ability of the material to absorb that radiation. Photocatalytic reactions depend upon the number of electron-hole pairs generated at the photocatalytic surface. The number of electron-hole pairs produced depends on the number of photons per unit area per second striking the surface that can be absorbed and whose energy exceeds the bandgap of the photocatalytic material. A convenient parameter to describe the number of useful photons is the number of moles of photons striking the surface per unit area per second. The unit of micro-einsteins (or micromoles) of photons per m2 per sec is commonly used for photochemical and photoelectric-like phenomena. This type of parameter is used in photochemistry, such as in the conversion of light energy for photosynthesis. Photosynthetic response correlates with the number of photons rather than by energy because, in this photochemical process, each molecule is activated by the absorption of one photon. In photosynthesis, the number of photons absorbed in the 400 700 nm spectral range is estimated and is referred to as photosynthetic active radiation (PAR). PAR is defined in terms of the photosynthetic photon flux density measured in micro-einsteins of photons per m2 per sec. PcAR is an equivalent, similarly modeled parameter that has been defined for the photocatalytic processes. Two methods to measure the PcAR level are being proposed. In the first method, a calibrated

  18. Dependence of biologically active UV radiation on the atmospheric ozone in 2000 - 2001 over Stara Zagora, Bulgaria

    International Nuclear Information System (INIS)

    This study investigates how the changes in simultaneously measured ozone columns influence the biologically active UV irradiance. Spectral ground-based measurements of direct solar ultraviolet radiation performed at Stara Zagora (42oN, 25oE), Bulgaria in 2000 - 2001 are used in conjunction with the total ozone content to investigate the relation to the biologically active UV radiation, depending on the solar zenith angle (SZA) and the ozone. The device measures the direct solar radiation in the range 290 - 360 nm at 1 nm resolution. The direct sun UV doses for some specific biological effects (erythema and eyes) are obtained as the integral in the wavelength interval between 290 and 330 nm of the UV solar spectrum weighted with an action spectrum, typical of each effect. For estimation of the sensitivity of biological doses to the atmospheric ozone we calculate the radiation amplification factor (RAF) defined as the percentage increase in the column amount of the atmospheric ozone. The biological doses increase significantly with the decrease of the SZA. The doses of SZA=20o are about three times larger than doses at SZA=50o. The RAF derived from our spectral measurements shows an increase of RAF along with the decreasing ozone. For example, the ozone reduction by 1% increases the erythemal dose by about 2%. (authors)

  19. Radiation measurement on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Akopova, A.B. [Yerevan Physics Institute, 2Alikhanyan Brs str, YerPhI, Yerevan (Armenia)]. E-mail: akopova@lx2.yerphi.am; Manaseryan, M.M. [Yerevan Physics Institute, 2Alikhanyan Brs str, YerPhI, Yerevan (Armenia); Melkonyan, A.A. [Yerevan Physics Institute, 2Alikhanyan Brs str, YerPhI, Yerevan (Armenia); Tatikyan, S.Sh. [Yerevan Physics Institute, 2Alikhanyan Brs str, YerPhI, Yerevan (Armenia); Potapov, Yu. [Research Center of Spacecraft Radiation Safety, Moscow (Russian Federation)

    2005-02-01

    The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380km and inclination 51.6{sup o} are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z>=2) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of dE/dx and during last years it has already been successfully used on board the MIR station, Space Shuttles and 'Kosmos' spacecrafts. An integral LET spectrum was measured in the range 0.5-2.2x103keV/{mu}m and the value of equivalent dose 360{mu}Sv/day was estimated. The flux of biologically dangerous heavy particles with Z>=2 was measured (3.85x103particles/cm2)

  20. Impact of Atmospheric Chromatic Effects on Weak Lensing Measurements

    Science.gov (United States)

    Meyers, Joshua E.; Burchat, Patricia R.

    2015-07-01

    Current and future imaging surveys will measure cosmic shear with statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We use analytic and computational techniques to study the impact on shape measurements of two atmospheric chromatic effects for ground-based surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope (LSST): (1) atmospheric differential chromatic refraction and (2) wavelength dependence of seeing. We investigate the effects of using the point-spread function (PSF) measured with stars to determine the shapes of galaxies that have different spectral energy distributions than the stars. We find that both chromatic effects lead to significant biases in galaxy shape measurements for current and future surveys, if not corrected. Using simulated galaxy images, we find a form of chromatic “model bias” that arises when fitting a galaxy image with a model that has been convolved with a stellar, instead of galactic, PSF. We show that both forms of atmospheric chromatic biases can be predicted (and corrected) with minimal model bias by applying an ordered set of perturbative PSF-level corrections based on machine-learning techniques applied to six-band photometry. Catalog-level corrections do not address the model bias. We conclude that achieving the ultimate precision for weak lensing from current and future ground-based imaging surveys requires a detailed understanding of the wavelength dependence of the PSF from the atmosphere, and from other sources such as optics and sensors. The source code for this analysis is available at https://github.com/DarkEnergyScienceCollaboration/chroma.

  1. Effect of atmospheric gases, surface albedo and cloud overlap on the absorbed solar radiation

    Directory of Open Access Journals (Sweden)

    Ashok Sinha

    Full Text Available Recent studies have provided new evidence that models may systematically underestimate cloud solar absorption compared to observations. This study extends previous work on this "absorption anomaly'' by using observational data together with solar radiative transfer parameterisations to calculate fs (the ratio of surface and top of the atmosphere net cloud forcings and its latitudinal variation for a range of cloud types. Principally, it is found that (a the zonal mean behaviour of fs varies substantially with cloud type, with the highest values obtained for low clouds; (b gaseous absorption and scattering can radically alter the pattern of the variation of fs with latitude, but gaseous effects cannot in general raise fs to the level of around 1.5 as recently determined; (c the importance of the gaseous contribution to the atmospheric ASR is such that whilst fs rises with surface albedo, the net cloud contribution to the atmospheric ASR falls; (d the assumed form of the degree of cloud overlap in the model can substantially affect the cloud contribution to the atmospheric ASR whilst leaving the parameter fs largely unaffected; (e even large uncertainties in the observed optical depths alone cannot account for discrepancies apparent between modelled and newly observed cloud solar absorption. It is concluded that the main source of the anomaly may derive from the considerable uncertainties regarding impure droplet microphysics rather than, or together with, uncertainties in macroscopic quantities. Further, variable surface albedos and gaseous effects may limit the use of contemporaneous satellite and ground-based measurements to infer the cloud solar absorption from the parameter fs.

  2. A new method to retrieve the aerosol layer absorption coefficient from airborne flux density and actinic radiation measurements

    OpenAIRE

    Bierwirth, Eike; Wendisch, Manfred; Jäkel, Evelyn; Ehrlich, André; Schmidt, K. Sebastian; Stark, Harald; Pilewskie, Peter; Esselborn, Michael; Gobbi, Gian Paolo; Ferrare, Richard; Müller, Thomas; Clarke, Antony

    2010-01-01

    A new method is presented to derive the mean value of the spectral absorption coefficient of an aerosol layer from combined airborne measurements of spectral net irradiance and actinic flux density. While the method is based on a theoretical relationship of radiative transfer theory, it is applied to atmospheric radiation measurements for the first time. The data have been collected with the Spectral Modular Airborne Radiation Measurement System (SMART‐Albedometer), the Solar Spectral Fl...

  3. Altitude profile of aerosols on Mars from measurements of its thermal radiation on limb

    Science.gov (United States)

    Moroz, V. I.; Titov, D. V.; Gektin, Yu. M.; Naraeva, M. K.; Selivanov, A. S.

    1993-01-01

    Measurements of the thermal (range 7 - 13 micrometers) radiation of Mars with the high space resolution (approximately 2 km) were made by the TERMOSKAN experiment of the Phobos mission. Some of the results were published earlier but only the surface radiation was analyzed in detail. However some part of these measurements was made near the limb of the planet. The atmosphere gives an important input here in the planetary thermal radiation. Beyond the limb the atmosphere is the only source. The task of this work is to estimate some characteristics of the atmosphere using brightness profiles of the thermal radiation near the limb. An appropriate model of the temperature profile T(h) is necessary for such an analysis. A set of T(h) models (nominal, maximal and minimal) was defined using various sources including MARSGRAM, Viking-1 lander data, its theoretical considerations and boundary layer models. On the next step the possible input of the atmospheric gaseous emissions (wing of CO2 15 micrometer band) was estimated. It was found that even for the maximal T(h) this input is no more than a few percents of the measured radiation beyond the limb. Consequently the aerosols are responsible for almost all measured emission. The analysis of the observed profile showed that these aerosols have two components: (1) exponential with the scale height about 10 km and (2) some layered structure (two layers with maxima about 23 and 33 km consisted probably of ice).

  4. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    OpenAIRE

    E. J. Morgan; J. V. Lavrič; Seifert, T.; T. Chicoine; Day, A; J. Gomez; Logan, R. (Robert); Sack, J.; Shuuya, T.; E. G. Uushona; K. Vincent; Schultz, U.; E.-G. Brunke; C. Labuschagne; Thompson, R. L.

    2015-01-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g....

  5. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    OpenAIRE

    Morgan, E.J.; J. V. Lavrič; Seifert, T; Chicoine, T.; Day, A; J. Gomez; Logan, R; Sack, J.; T. Shuuya; Uushona, E.G.; K. Vincent; U. Schultz; Brunke, E.-G.; C. Labuschagne; R. L. Thompson

    2015-01-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the north...

  6. Radiated BPF sound measurement of centrifugal compressor

    International Nuclear Information System (INIS)

    A technique to measure radiated BPF sound from an automotive turbocharger compressor impeller is proposed in this paper. Where there are high-level background noises in the measurement environment, it is difficult to discriminate the target component from the background. Since the effort of measuring BPF sound was taken in a room with such condition in this study, no discrete BPF peak was initially found on the sound spectrum. Taking its directionality into consideration, a microphone covered with a parabolic cone was selected and using this technique, the discrete peak of BPF was clearly observed. Since the level of measured sound was amplified due to the area-integration effect, correction was needed to obtain the real level. To do so, sound measurements with and without a parabolic cone were conducted for the fixed source and their level differences were used as correction factors. Consideration is given to the sound propagation mechanism utilizing measured BPF as well as the result of a simple model experiment. The present method is generally applicable to sound measurements conducted with a high level of background noise

  7. Radiated BPF sound measurement of centrifugal compressor

    Science.gov (United States)

    Ohuchida, S.; Tanaka, K.

    2013-12-01

    A technique to measure radiated BPF sound from an automotive turbocharger compressor impeller is proposed in this paper. Where there are high-level background noises in the measurement environment, it is difficult to discriminate the target component from the background. Since the effort of measuring BPF sound was taken in a room with such condition in this study, no discrete BPF peak was initially found on the sound spectrum. Taking its directionality into consideration, a microphone covered with a parabolic cone was selected and using this technique, the discrete peak of BPF was clearly observed. Since the level of measured sound was amplified due to the area-integration effect, correction was needed to obtain the real level. To do so, sound measurements with and without a parabolic cone were conducted for the fixed source and their level differences were used as correction factors. Consideration is given to the sound propagation mechanism utilizing measured BPF as well as the result of a simple model experiment. The present method is generally applicable to sound measurements conducted with a high level of background noise.

  8. Measuring concentrations of elements using neutron radiation

    International Nuclear Information System (INIS)

    An apparatus for measuring the concentrations of elements in a material by the capture gamma method is claimed. The apparatus comprises either an isotope source or a neutron generator as the neutron source, a semi-conductor detector as the gamma-radiation detector, and a moderator which is, at least in part, heavy water. The detector is adapted to be placed adjacent to or inside a specimen in the flux of slow neutrons so that sufficient moderator is disposed between the source and the sample-detector combination that only relatively few fast neutrons will reach the detector

  9. Fundamentals of radiation protection measuring technique

    International Nuclear Information System (INIS)

    Stationary radiation protection measuring systems (local dose rate systems) are widely distributed. Since January 1sup(st), 1983 a number of these systems must be calibrated by a gauging office if they are used on the basis of legal regulations. The design type requirements made by the PTB in connection with the calibration duty as well as the transitional regulations for local dose rate systems already in operation have been prepared by a working committee including members of users, suppliers, gange supervising authorities, Technische Ueberwachungs-Vereine and the PTB. (orig./DG)

  10. Measurement of Atmospheric Neutrino Oscillations with the ANTARES Neutrino Telescope

    CERN Document Server

    Adrian-Martinez, S; Albert, A; Andre, M; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Astraatmadja, T; Aubert, J -J; Baret, B; Basa, S; Bertin, V; Biagi, S; Bigongiari, C; Bogazzi, C; Bou-Cabo, M; Bouhou, B; Bouwhuis, M C; Brunner, J; Busto, J; Capone, A; Carloganu, C; Carr, J; Cecchini, S; Charif, Z; Charvis, Ph; Chiarusi, T; Circella, M; Coniglione, R; Core, L; Costantini, H; Coyle, P; Creusot, A; Curtil, C; De Bonis, G; Decowski, M P; Dekeyser, I; Deschamps, A; Distefano, C; Donzaud, C; Dornic, D; Dorosti, Q; Drouhin, D; Eberl, T; Emanuele, U; Enzenhoefer, A; Ernenwein, J -P; Escoffier, S; Fehn, K; Fermani, P; Ferri, M; Ferry, S; Flaminio, V; Folger, F; Fritsch, U; Fuda, J -L; Galata, S; Gay, P; Geyer, K; Giacomelli, G; Giordano, V; Gleixner, A; Gomez-Gonzalez, J P; Graf, K; Guillard, G; Hallewell, G; Hamal, M; van Haren, H; Heijboer, A J; Hello, Y; Hernandez-Rey, J J; Herold, B; Hoessl, J; Hsu, C C; de Jong, M; Kadler, M; Kalekin, O; Kappes, A; Katz, U; Kavatsyuk, O; Kooijman, P; Kopper, C; Kouchner, A; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lambard, G; Larosa, G; Lattuada, D; Lefevre, D; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Louis, F; Mangano, S; Marcelin, M; Margiotta, A; Martinez-Mora, J A; Meli, A; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Neff, M; Nezri, E; Palioselitis, D; Pavalas, G E; Payet, K; Petrovic, J; Piattelli, P; Popa, V; Pradier, T; Presani, E; Racca, C; Reed, C; Riccobene, G; Richardt, C; Richter, R; Riviere, C; Robert, A; Roensch, K; Rostovtsev, A; Ruiz-Rivas, J; Rujoiu, M; Russo, G V; Samtleben, D F E; Sanchez-Losa, A; Sapienza, P; Schmid, J; Schnabel, J; Schoeck, F; Schuller, J -P; Schuessler, F; Seitz, T; Shanidze, R; Simeone, F; Spies, A; Spurio, M; Steijger, J J M; Stolarczyk, Th; Taiuti, M; Tamburini, C; Trovato, A; Vallage, B; Vallee, C; Van Elewyck, V; Vecchi, M; Vernin, P; Visser, E; Wagner, S; Wijnker, G; Wilms, J; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zuniga, J

    2012-01-01

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximum mixing, a mass difference of $\\Delta m_{32}^2=(3.1\\pm 0.9)\\cdot 10^{-3}$ eV$^2$ is obtained, in good agreement with the world average value.

  11. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Al Samarai, I. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Albert, A. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, 68008 Colmar (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposicio, 08800 Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service d' Electronique des Detecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Ardid, M. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Astraatmadja, T. [Nikhef, Science Park, Amsterdam (Netherlands); Aubert, J.-J. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); and others

    2012-08-14

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass difference of {Delta}m{sub 32}{sup 2}=(3.1{+-}0.9) Dot-Operator 10{sup -3} eV{sup 2} is obtained, in good agreement with the world average value.

  12. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass difference of Δm322=(3.1±0.9)⋅10-3 eV2 is obtained, in good agreement with the world average value.

  13. Direct measurements of the effect of biomass burning over the Amazon on the atmospheric temperature profile

    Directory of Open Access Journals (Sweden)

    L. Remer

    2009-11-01

    Full Text Available Aerosols suspended in the atmosphere interact with solar radiation and clouds, thus change the radiation energy fluxes in the atmospheric column. In this paper we measure changes in the atmospheric temperature profile as a function of the smoke loading and the cloudiness, over the Amazon basin, during the dry seasons (August and September of 2005–2008. We show that as the aerosol optical depth (AOD increases from 0.02 to a value of ~0.6, there is a decrease of ~4°C at 1000 hPa, and an increase of ~1.5°C at 850 hPa. The warming of the aerosol layer at 850 hPa is likely due to aerosol absorption when the particles are exposed to direct illumination by the sun. The large values of cooling in the lower layers could be explained by a combination of aerosol extinction of the solar flux in the layers aloft together with an aerosol-induced increase of cloud cover which shade the lower atmosphere. We estimate that the increase in cloud fraction due to aerosol contributes about half of the observed cooling in the lower layers.

  14. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    OpenAIRE

    Solomon, S. J.; Custer, T.; G. Schade; Soares Dias, A. P.; J. Burrows

    2005-01-01

    A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w) of the...

  15. Radiative transfer with scattering for domain-decomposed 3D MHD simulations of cool stellar atmospheres

    CERN Document Server

    Hayek, W; Carlsson, M; Trampedach, R; Collet, R; Gudiksen, B V; Hansteen, V H; Leenaarts, J

    2010-01-01

    We present the implementation of a radiative transfer solver with coherent scattering in the new BIFROST code for radiative magneto-hydrodynamical (MHD) simulations of stellar surface convection. The code is fully parallelized using MPI domain decomposition, which allows for large grid sizes and improved resolution of hydrodynamical structures. We apply the code to simulate the surface granulation in a solar-type star, ignoring magnetic fields, and investigate the importance of coherent scattering for the atmospheric structure. A scattering term is added to the radiative transfer equation, requiring an iterative computation of the radiation field. We use a short-characteristics-based Gauss-Seidel acceleration scheme to compute radiative flux divergences for the energy equation. The effects of coherent scattering are tested by comparing the temperature stratification of three 3D time-dependent hydrodynamical atmosphere models of a solar-type star: without scattering, with continuum scattering only, and with bo...

  16. The role of atmospheric radiation in the generation and maintenance of circulations of different scales

    International Nuclear Information System (INIS)

    It is well known that the radiation budget of the atmosphere is an important component of the earth's climate system. On shorter time scales, radiative transfer affects the evolution of atmospheric circulation, principally through interaction with cloud and storm systems, and destabilizes the atmosphere continuously. This destabilization is important for subsequent development of clouds and storm systems. The clouds and storm systems feed back to the radiation budget, as clouds significantly alter both shortwave and longwave radiative transfer. It is important to understand the role that radiative transfer plays in the evolution of these circulation systems to accurately quantify the radiation budget. The results presented here are from modeling studies designed to isolate the effect of radiative transfer on the generation of circulation systems of different spatial and temporal scales. Two different numerical weather prediction models were used and will be described briefly in the next section. Following that, the radiative transfer model that was used with both circulation models will be described. Finally, results from the modeling studies will be presented, and conclusions and future research efforts will be discussed

  17. Radiative transfer in CO2-rich atmospheres: 1. Collisional line mixing implies a colder early Mars

    Science.gov (United States)

    Ozak, N.; Aharonson, O.; Halevy, I.

    2016-06-01

    Fast and accurate radiative transfer methods are essential for modeling CO2-rich atmospheres, relevant to the climate of early Earth and Mars, present-day Venus, and some exoplanets. Although such models already exist, their accuracy may be improved as better theoretical and experimental constraints become available. Here we develop a unidimensional radiative transfer code for CO2-rich atmospheres, using the correlated k approach and with a focus on modeling early Mars. Our model differs from existing models in that it includes the effects of CO2 collisional line mixing in the calculation of the line-by-line absorption coefficients. Inclusion of these effects results in model atmospheres that are more transparent to infrared radiation and, therefore, in colder surface temperatures at radiative-convective equilibrium, compared with results of previous studies. Inclusion of water vapor in the model atmosphere results in negligible warming due to the low atmospheric temperatures under a weaker early Sun, which translate into climatically unimportant concentrations of water vapor. Overall, the results imply that sustained warmth on early Mars would not have been possible with an atmosphere containing only CO2 and water vapor, suggesting that other components of the early Martian climate system are missing from current models or that warm conditions were not long lived.

  18. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere

    International Nuclear Information System (INIS)

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author)

  19. Atmospheric extinction in solar tower plants: the Absorption and Broadband Correction for MOR measurements

    Directory of Open Access Journals (Sweden)

    N. Hanrieder

    2015-05-01

    Full Text Available Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrating solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in raytracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested and more than 19 months of measurements were collected at the Plataforma Solar de Almería and compared. Both instruments are primarily used to determine the meteorological optical range (MOR. The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for Concentrating Solar Power (CSP, a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the actual, time-dependent by the collector reflected solar spectrum. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the Absorption and Broadband Correction (ABC procedure

  20. Atmospheric extinction in solar tower plants: the Absorption and Broadband Correction for MOR measurements

    Science.gov (United States)

    Hanrieder, N.; Wilbert, S.; Pitz-Paal, R.; Emde, C.; Gasteiger, J.; Mayer, B.; Polo, J.

    2015-05-01

    Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrating solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in raytracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested and more than 19 months of measurements were collected at the Plataforma Solar de Almería and compared. Both instruments are primarily used to determine the meteorological optical range (MOR). The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED) light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for Concentrating Solar Power (CSP), a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the actual, time-dependent by the collector reflected solar spectrum. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the Absorption and Broadband Correction (ABC) procedure, additional

  1. Radiative lifetime measurements of rubidium Rydberg states

    International Nuclear Information System (INIS)

    We have measured the radiative lifetimes of ns, np and nd Rydberg states of rubidium in the range 28 ≤ n ≤ 45. To enable long-lived states to be measured, our experiment uses slow-moving (∼100 μK) 85Rb atoms in a magneto-optical trap (MOT). Two experimental techniques have been adopted to reduce random and systematic errors. First, a narrow-bandwidth pulsed laser is used to excite the target nl Rydberg state, resulting in minimal shot-to-shot variation in the initial state population. Second, we monitor the target state population as a function of time delay from the laser pulse using a short-duration, millimetre-wave pulse that is resonant with a one- or two-photon transition to a higher energy 'monitor state', n'l'. We then selectively field ionize the monitor state, and detect the resulting electrons with a micro-channel plate. This signal is an accurate mirror of the nl target state population, and is uncontaminated by contributions from other states which are populated by black body radiation. Our results are generally consistent with other recent experimental results obtained using a method which is more prone to systematic error, and are also in excellent agreement with theory.

  2. Condition of Retrieving Vertical Column Density of Atmospheric Pollution Gases by Using Scattered Solar Radiation

    International Nuclear Information System (INIS)

    We present a method to monitor the vertical column density (VCD) of atmospheric pollution gases by using the scattered solar radiation. The necessary condition of capturing the useful scattered solar radiation is achieved. The condition is only dependent on the solar elevation angle, while independent of the solar azimuth angle, which could greatly simply the capturing equipment and procedure. Under the condition, the VCD of tropospheric NO2 in Chengdu, China is retrieved from the scattered solar radiation, which is close to that from the direct solar radiation

  3. Condition of Retrieving Vertical Column Density of Atmospheric Pollution Gases by Using Scattered Solar Radiation

    Institute of Scientific and Technical Information of China (English)

    ZUO Sao-Yi

    2009-01-01

    We present a method to monitor the vertical column density (VCD) of atmospheric pollution gases by using the scattered solar radiation. The necessary condition of capturing the useful scattered solar radiation is achieved. The condition is only dependent on the solar elevation angle, while independent of the solar azimuth angle, which could greatly simply the capturing equipment and procedure. Under the condition, the VCD of tropospheric NO2 in Chengdu, China is retrieved from the scattered solar radiation, which is dose to that from the direct solar radiation.

  4. A spectroscopic transfer standard for accurate atmospheric CO measurements

    Science.gov (United States)

    Nwaboh, Javis A.; Li, Gang; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker

    2016-04-01

    Atmospheric carbon monoxide (CO) is a precursor of essential climate variables and has an indirect effect for enhancing global warming. Accurate and reliable measurements of atmospheric CO concentration are becoming indispensable. WMO-GAW reports states a compatibility goal of ±2 ppb for atmospheric CO concentration measurements. Therefore, the EMRP-HIGHGAS (European metrology research program - high-impact greenhouse gases) project aims at developing spectroscopic transfer standards for CO concentration measurements to meet this goal. A spectroscopic transfer standard would provide results that are directly traceable to the SI, can be very useful for calibration of devices operating in the field, and could complement classical gas standards in the field where calibration gas mixtures in bottles often are not accurate, available or stable enough [1][2]. Here, we present our new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor capable of performing absolute ("calibration free") CO concentration measurements, and being operated as a spectroscopic transfer standard. To achieve the compatibility goal stated by WMO for CO concentration measurements and ensure the traceability of the final concentration results, traceable spectral line data especially line intensities with appropriate uncertainties are needed. Therefore, we utilize our new high-resolution Fourier-transform infrared (FTIR) spectroscopy CO line data for the 2-0 band, with significantly reduced uncertainties, for the dTDLAS data evaluation. Further, we demonstrate the capability of our sensor for atmospheric CO measurements, discuss uncertainty calculation following the guide to the expression of uncertainty in measurement (GUM) principles and show that CO concentrations derived using the sensor, based on the TILSAM (traceable infrared laser spectroscopic amount fraction measurement) method, are in excellent agreement with gravimetric values. Acknowledgement Parts of this work have been

  5. Optimizing a remote sensing instrument to measure atmospheric surface pressure

    Science.gov (United States)

    Peckham, G. E.; Gatley, C.; Flower, D. A.

    1983-01-01

    Atmospheric surface pressure can be remotely sensed from a satellite by an active instrument which measures return echoes from the ocean at frequencies near the 60 GHz oxygen absorption band. The instrument is optimized by selecting its frequencies of operation, transmitter powers and antenna size through a new procedure baesd on numerical simulation which maximizes the retrieval accuracy. The predicted standard deviation error in the retrieved surface pressure is 1 mb. In addition the measurements can be used to retrieve water vapor, cloud liquid water and sea state, which is related to wind speed.

  6. Controlled Atmosphere High Temperature SPM for electrochemical measurements

    International Nuclear Information System (INIS)

    A new controlled atmosphere high temperature SPM has been designed and build for the purpose of performing electrochemical measurements on solid oxide fuel cell materials. The first tests show that images can be obtained at a surface temperature of 465deg. C in air with a standard AFM AC probe. The aim is to produce images at a surface temperature of 800deg. C with electrically conducting ceramic probes as working electrodes that can be positioned at desired locations at the surface for electrochemical measurements

  7. A review on recent upper atmosphere atomic oxygen measurements

    Science.gov (United States)

    Kaufmann, Martin; Ern, Manfred; Riese, Martin; Zhu, Yajun

    2016-07-01

    Atomic oxygen is a key player in the upper mesosphere lower and thermosphere chemistry, energy balance, and dynamics. In recent years, a few new global datasets of this species have been presented. They are based on airglow measurements from low earth satellites. Surprisingly, the atomic oxygen abundance differs by 30-50% for similar atmospheric conditions. This paper gives an overview on the various atomic oxygen datasets available so far and presents most recent results obtained from measurements of the SCIAMACHY instrument on Envisat. Differences between the datasets are discussed.

  8. Mineral Dust Impact on Short- and Long-Wave Radiation and Comparison with Ceres Measurements

    Science.gov (United States)

    Romano, Salvatore; Perrone, Maria Rita

    2016-06-01

    Clear-sky downward and upward radiative flux measurements both in the short- and in the long-wave spectral range have been used to estimate and analyze the radiation changes at the surface due to the mineral dust advection at a Central Mediterranean site. Then, short- and long-wave radiative fluxes retrieved from the CERES (Clouds and the Earth's Radiant Energy System) radiometer sensors operating on board the EOS (Earth Observing System) AQUA and TERRA platforms have been used to evaluate the mineral dust radiative impact at the top of the atmosphere. Satellite-derived radiative fluxes at the surface have been compared with corresponding ground-based flux measurements, collocated in space and time, to better support and understand the desert dust radiative impact. Results referring to the year 2012 are reported.

  9. Aerosols in the Convective Boundary Layer: Radiation Effects on the Coupled Land-Atmosphere System

    Science.gov (United States)

    Barbaro, E.; Vila-Guerau Arellano, J.; Ouwersloot, H. G.; Schroter, J.; Donovan, D. P.; Krol, M. C.

    2013-12-01

    We investigate the responses of the surface energy budget and the convective boundary-layer (CBL) dynamics to the presence of aerosols using a combination of observations and numerical simulations. A detailed observational dataset containing (thermo)dynamic variables observed at CESAR (Cabauw Experimental Site for Atmospheric Research) and aerosol information from the European Integrated Project on Aerosol, Cloud, Climate, and Air Quality Interactions (IMPACT/EUCAARI) campaign is employed to design numerical experiments reproducing two prototype clear-sky days characterized by: (i) a well-mixed residual layer above a ground inversion and (ii) a continuously growing CBL. A large-eddy simulation (LES) model and a mixed-layer (MXL) model, both coupled to a broadband radiative transfer code and a land-surface model, are used to study the impacts of aerosol scattering and absorption of shortwave radiation on the land-atmosphere system. We successfully validate our model results using the measurements of (thermo)dynamic variables and aerosol properties for the two different CBL prototypes studied here. Our findings indicate that in order to reproduce the observed surface energy budget and CBL dynamics, information of the vertical structure and temporal evolution of the aerosols is necessary. Given the good agreement between the LES and the MXL model results, we use the MXL model to explore the aerosol effect on the land-atmosphere system for a wide range of optical depths and single scattering albedos. Our results show that higher loads of aerosols decrease irradiance, imposing an energy restriction at the surface. Over the studied well-watered grassland, aerosols reduce the sensible heat flux more than the latent heat flux. As a result, aerosols increase the evaporative fraction. Moreover, aerosols also delay the CBL morning onset and anticipate its afternoon collapse. If also present above the CBL during the morning transition, aerosols maintain a persistent near

  10. Integrated method for the measurement of trace atmospheric bases

    Directory of Open Access Journals (Sweden)

    D. Key

    2011-09-01

    Full Text Available Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  11. Integrated method for the measurement of trace nitrogenous atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-12-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv), as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  12. Integrated method for the measurement of trace atmospheric bases

    Science.gov (United States)

    Key, D.; Stihle, J.; Petit, J.-E.; Bonnet, C.; Depernon, L.; Liu, O.; Kennedy, S.; Latimer, R.; Burgoyne, M.; Wanger, D.; Webster, A.; Casunuran, S.; Hidalgo, S.; Thomas, M.; Moss, J. A.; Baum, M. M.

    2011-09-01

    Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace atmospheric nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  13. Modeled black carbon radiative forcing and atmospheric lifetime in AeroCom Phase II constrained by aircraft observations

    Directory of Open Access Journals (Sweden)

    B. H. Samset

    2014-08-01

    Full Text Available Atmospheric black carbon (BC absorbs solar radiation, and exacerbates global warming through exerting positive radiative forcing (RF. However, the contribution of BC to ongoing changes in global climate is under debate. Anthropogenic BC emissions, and the resulting distribution of BC concentration, are highly uncertain. In particular, long range transport and processes affecting BC atmospheric lifetime are poorly understood. Here we discuss whether recent assessments may have overestimated present day BC radiative forcing in remote regions. We compare vertical profiles of BC concentration from four recent aircraft measurement campaigns to simulations by 13 aerosol models participating in the AeroCom Phase II intercomparision. An atmospheric lifetime of BC of less than 5 days is shown to be essential for reproducing observations in remote ocean regions, in line with other recent studies. Adjusting model results to measurements in remote regions, and at high altitudes, leads to a 25% reduction in AeroCom Phase II median direct BC forcing, from fossil fuel and biofuel burning, over the industrial era. The sensitivity of modeled forcing to BC vertical profile and lifetime highlights an urgent need for further flight campaigns, close to sources and in remote regions, to provide improved quantification of BC effects for use in climate policy.

  14. Atmospheric flow measurements using the PIV and HWA techniques

    Directory of Open Access Journals (Sweden)

    Luciana Bassi Marinho Pires

    2010-08-01

    Full Text Available Alcântara Space Center (ASC is the Brazilian gate to the space where rockets of different sizes are launched. At ASC there is a relative topographical variation, coastal cliff, which modifies the atmospheric boundary layer characteristics and can cause interference for operations of rockets. In the present work, a simplified model (mock-up was studied in a wind tunnel. A scale factor of 1:1000 was used and the atmospheric flow was measured using the hot wire anemometer (HWA and particle image velocimetry (PIV techniques. Using of HWA it was possible to calculate values of average wind speed and fluctuations in a set of points of the section of tests that representing the region of the ASC. Through these measures, other meteorological parameters that represent the atmospheric flow, such as the friction velocity (u*, the roughness length (z0 from the logarithmic profile and the alpha exponent (ɑ of the power law were calculated. With the use of the PIV´s technique, the streamlines and the vorticity fields were obtained and it was noticed that the vorticity generated downwind of the coastal cliff has a strong turbulence (vorticities around 2000 sˉ¹. A rectangular building (simulating the mobile integration tower was inserted at the mock-up and the downwind turbulence was similar to the one generated by the coastal cliff.

  15. A new model on bidirectional reflectance surface-atmospheric coupled radiation

    Institute of Scientific and Technical Information of China (English)

    QIU; Jinhuan; (邱金桓)

    2001-01-01

    An exact and available model on bidirectional reflectance surface-atmospheric coupled radiation is of great significance for spaceborne remote sensing application. Based on the physical process of interaction of solar radiation with the surface and the atmosphere, a new model on bidirectional reflectance surface-atmospheric coupled radiation is developed in this paper. As shown in numerical simulation, this model is evidently better than the 6S model. The standard error among 110112 sets of upward radiance data calculated by this new model is only 0.49%, which is about one fourth of the one by 6S. In the condition of the solar zenith angle qs≤75°and the viewing angle qv≤60°, the error by the new model is usually smaller than 2.5%.

  16. Cosmic ray modulation of infra-red radiation in the atmosphere

    CERN Document Server

    Aplin, K L

    2012-01-01

    Cosmic rays produce charged molecular clusters by ionisation as they pass through the lower atmosphere. Neutral molecular clusters such as dimers and complexes are expected to make a small contribution to the radiative balance, but atmospheric absorption by charged clusters has not hitherto been observed. In an atmospheric experiment, a filter radiometer tuned to the 9.15 um absorption band associated with infra-red absorption of charged molecular clusters was used to monitor changes immediately following events identified by a cosmic ray telescope sensitive to high energy (>400MeV) particles, principally muons. The change in longwave radiation in this absorption band due to charged molecular clusters is 7 mW^m-2. The integrated atmospheric energy change for each event is 2J, representing an amplification factor of 10^10 compared to the 2GeV energy of a typical tropospheric cosmic ray. This absorption is expected to occur continuously and globally.

  17. About Solar Radiation Intensity Measurements and Data Processing

    OpenAIRE

    MICH-VANCEA Claudiu; GORDAN Ioan Mircea

    2012-01-01

    Measuring the intensity of solar radiation is one of the directions of investigation necessary for the implementation of photovoltaic systems in a particular geographical area. This can be done by using specific measuring equipment (pyranometer) sensors based onthermal or photovoltaic principle. In this paper it is presented a method for measuring solar radiation (which has two main components - direct radiation and diffuse radiation) with sensors based on photovoltaic principle. Such data ar...

  18. Measurement of the atmospheric muon flux with the ANTARES detector

    CERN Document Server

    Bazzotti, Marco

    2009-01-01

    ANTARES is a submarine neutrino telescope deployed in the Mediterranean Sea, at a depth of about 2500 m. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. Down-going muons produced in atmospheric showers are a physical background to the neutrino detection, and are being studied. In this paper the measurement of the Depth Intensity Relation (DIR) of atmospheric muon flux is presented. The data collected in June and July 2007, when the ANTARES detector was in its 5-line configuration, are used in the analysis. The corresponding livetime is $724 h$. A deconvolution method based on a Bayesian approach was developed, which takes into account detector and reconstruction inefficiencies. Comparison with other experimental results and Monte Carlo expectations are presented and discussed.

  19. Radiation damage measurements in room-temperature semiconductor radiation detectors

    CERN Document Server

    Franks, L A; Olsen, R W; Walsh, D S; Vizkelethy, G; Trombka, J I; Doyle, B L; James, R B

    1999-01-01

    The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI sub 2) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10 sup 1 sup 0 p/cm sup 2 and significant bulk leakage after 10 sup 1 sup 2 p/cm sup 2. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5x10 sup 9 p/cm sup 2 in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from a moderated fission spectrum of neutrons after fluences up to 10 sup 1 sup 0 n/cm sup 2 , although activation was evident. Exposures of CZT to 5 MeV alpha particles at fluences up to 1.5x10 sup 1 sup 0 alpha/cm sup 2 produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5x10 sup 9 alpha/cm sup 2. CT detectors show resolution...

  20. Cosmic Radiation Measurements in Airline Service

    International Nuclear Information System (INIS)

    Ionising radiation monitoring equipment is installed in all Concordes and much data have been derived. To validate the measurements from the on-board monitoring equipment, a programme of measurements on Concorde has been carried out using passive dosemeters in association with the UK National Radiological Protection Board. Data from a typical month (in this case October 1997) shows an arithmetic mean dose across the British Airways Concorde fleet of 12.9 (±0.4) μSv.h-1. Results from the NRPB measurements for the same month give a dose of 11.4 (±0.5) μSv.h-1 and application of the CARI 3Q programme gives a dose of 9.6 μSv.h-1 for the same month. The effective route dose between London and New York gives a mean value of 43.1 μSv for the Concorde detectors. The NRPB results give a route dose of 38.9 μSv whereas the CARI 3Q programme gives a route dose of 32.5 μSv. Measurements have also been performed on the Boeing 747-400 aircraft on the high latitude ultralonghaul direct London-Tokyo flight and these give values in the region of 6 μSv.h-1, against the CARI 3Q estimate of 3.7 μSv.h-1. (author)

  1. he Impact of Primary Marine Aerosol on Atmospheric Chemistry, Radiation and Climate: A CCSM Model Development Study

    Energy Technology Data Exchange (ETDEWEB)

    Keene, William C. [University of Virginia; Long, Michael S. [University of Virginia

    2013-05-20

    This project examined the potential large-scale influence of marine aerosol cycling on atmospheric chemistry, physics and radiative transfer. Measurements indicate that the size-dependent generation of marine aerosols by wind waves at the ocean surface and the subsequent production and cycling of halogen-radicals are important but poorly constrained processes that influence climate regionally and globally. A reliable capacity to examine the role of marine aerosol in the global-scale atmospheric system requires that the important size-resolved chemical processes be treated explicitly. But the treatment of multiphase chemistry across the breadth of chemical scenarios encountered throughout the atmosphere is sensitive to the initial conditions and the precision of the solution method. This study examined this sensitivity, constrained it using high-resolution laboratory and field measurements, and deployed it in a coupled chemical-microphysical 3-D atmosphere model. First, laboratory measurements of fresh, unreacted marine aerosol were used to formulate a sea-state based marine aerosol source parameterization that captured the initial organic, inorganic, and physical conditions of the aerosol population. Second, a multiphase chemical mechanism, solved using the Max Planck Institute for Chemistry's MECCA (Module Efficiently Calculating the Chemistry of the Atmosphere) system, was benchmarked across a broad set of observed chemical and physical conditions in the marine atmosphere. Using these results, the mechanism was systematically reduced to maximize computational speed. Finally, the mechanism was coupled to the 3-mode modal aerosol version of the NCAR Community Atmosphere Model (CAM v3.6.33). Decadal-scale simulations with CAM v.3.6.33, were run both with and without reactive-halogen chemistry and with and without explicit treatment of particulate organic carbon in the marine aerosol source function. Simulated results were interpreted (1) to evaluate influences

  2. Impact of uncertainties in atmospheric mixing on simulated UTLS composition and related radiative effects

    OpenAIRE

    Riese, Martin; Ploeger, F; Rap, A.; B. Vogel; P. Konopka; Dameris, Martin; Forster, P

    2012-01-01

    The upper troposphere/lower stratosphere (UTLS) region plays an important role in the climate system. Changes in the structure and chemical composition of this region result in particularly large changes in radiative forcings of the atmosphere. Quantifying the processes that control UTLS composition (e.g., stratosphere-troposphere exchange) therefore represents a crucial task. We assess the influence of uncertainties in the atmospheric mixing strength on global UTLS distributions of greenh...

  3. Novel atmospheric extinction measurement techniques for aerospace laser system applications

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark

    2013-01-01

    Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

  4. Visualization of Radiation Environment on Mars: Assessment with MARIE Measurements

    Science.gov (United States)

    Saganti, P.; Cucinotta, F.; Zeitlin, C.; Cleghorn, T.; Flanders, J.; Riman, F.; Hu, X.; Pinsky, L.; Lee, K.; Anderson, V.; Atwell, W.; Turner, R.

    2003-01-01

    For a given GCR (Galactic Cosmic Ray) environment at Mars, particle flux of protons, alpha particles, and heavy ions, are also needed on the surface of Mars for future human exploration missions. For the past twelve months, the MARJE (Martian Radiation Environment Experiment) instrument onboard the 200J Mars Odyssey has been providing the radiation measurements from the Martian orbit. These measurements are well correlated with the HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations during these specific GCR environment conditions are now extended and transported through the CO2 atmosphere onto the Martian surface. These calculated pa11icle flux distributions are presented as a function of the Martian topography making use of the MOLA (Mars Orbiter Laser Altimeter) data from the MGS (Mars Global Surveyor). Also, particle flux calculations are presented with visualization in the human body from skin depth to the internal organs including the blood-forming organs.

  5. Visualization of radiation environment on Mars: assessment with MARIE measurements

    International Nuclear Information System (INIS)

    Full text: For a given GCR (Galactic Cosmic Ray) environment at Mars, particle flux of protons, alpha particles, and heavy ions, are also needed on the surface of Mars for future human exploration missions. For the past twelve months, the MARIE (Martian Radiation Environment Experiment) instrument onboard the 2001 Mars Odyssey has been providing the radiation measurements from the Martian orbit. These measurements are well correlated with the HZETRN (High Z and Energy Transport) and QMSFRG (Quantum Multiple-Scattering theory of nuclear Fragmentation) model calculations. These model calculations during these specific GCR environment conditions are now extended and transported through the CO2 atmosphere onto the Martian surface. These calculated particle flux distributions are presented as a function of the Martian topography making use of the MOLA (Mars Orbiter Laser Altimeter) data from the MGS (Mars Global Surveyor). Also, particle flux calculations are presented with visualization in the human body from skin depth to the internal organs including the blood-forming organs

  6. Atmospheric circulation of tidally locked exoplanets II: dual-band radiative transfer and convective adjustment

    CERN Document Server

    Heng, Kevin; Phillipps, Peter J

    2011-01-01

    Improving upon our purely dynamical work, we present three-dimensional simulations of the atmospheric circulation on Earth-like (exo)planets and hot Jupiters using the GFDL-Princeton Flexible Modeling System (FMS). As the first steps away from the purely dynamical benchmarks of Heng, Menou & Phillipps (2011), we add dual-band radiative transfer and dry convective adjustment schemes to our computational setup. Our treatment of radiative transfer assumes stellar irradiation to peak at a wavelength shorter than and distinct from that at which the exoplanet re-emits radiation ("shortwave" versus "longwave"), and also uses a two-stream approximation. Convection is mimicked by adjusting unstable lapse rates to the dry adiabat. The bottom of the atmosphere is bounded by an uniform slab with a finite thermal inertia. For our hot Jupiter models, we include an analytical formalism for calculating temperature-pressure profiles, in radiative equilibrium, which accounts for the effect of collision-induced absorption v...

  7. Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms

    Directory of Open Access Journals (Sweden)

    S.-L. Sihto

    2006-05-01

    Full Text Available We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took place in spring 2003 in Hyytiälä (Finland. During the campaign numerous new aerosol particle formation events occurred of which 15 were accompanied by gaseous sulphuric acid measurements. Our detailed analysis of these 15 events is focussed on nucleation and early growth (to a diameter of 3 nm of fresh particles. It revealed that new particle formation seems to be a function of the gaseous sulphuric acid concentration to the power from one to two. The former would be consistent with the recently developed activation theory while the latter would be consistent with the kinetic nucleation theory. We find that some events are dominated by the activation mechanism and some are dominated by the kinetic mechanism. Inferred coefficients for the two nucleation mechanisms are correlated with the product of gaseous sulphuric acid and ammonia concentrations. This indicates that besides gaseous sulphuric acid also ammonia has a role in nucleation. Early growth of fresh particles to a diameter of 3 nm has a mean rate of 1.2 nm/h and is clearly correlated with the gaseous sulphuric acid concentration.

  8. POES SEM-2 observations of radiation belt dynamics and energetic electron precipitation in to the atmosphere

    International Nuclear Information System (INIS)

    Complete text of publication follows. The coupling of the Van Allen radiation belts to the Earth's atmosphere through the effects of precipitating particles is an area of intense scientific interest. Currently, there are significant uncertainties surrounding the precipitating characteristics of medium energy electrons (>20 keV), and even more uncertainties for relativistic electrons. In this paper we examine roughly ten-years of measurements of trapped and precipitating electrons available from the Polar Orbiting Environmental Satellites (POES)/Space Environment Monitor (SEM-2) which has provided long-term global data in this energy range. Relativistic electron increases are associated with both interplanetary Coronal Mass Ejections (ICMEs) and periodic high speed solar wind streams (HSSWS). The processes triggered by ICMEs are roughly twice as effective at enhancing POES-observed electrons to relativistic energies as the processes triggered by HSSWS. We find that ICME-associated increases can extend down to L∼2, while other enhancements are generally limited to L>3.5. Finally, during HSSWS conditions there is an energy-dependent time delay observed in the POES/SEM-2 observations, with the >800 keV relativistic electron enhancement delayed by ∼1-week relative to the >30 keV electron enhancement, probably due to the timescales of the acceleration processes. One possible interpretation of this is a two-stage process, where relatively rapid acceleration initially takes place near the geomagnetic equator as predicted by theory and observed experimentally. This is followed by a much slower process, where the relativistic electrons scatter towards the atmosphere loss cone at a rate which is energy dependent. Such large delays should have consequences for the timing of the atmospheric impact of HSSWS-triggered geomagnetic storms.

  9. On measures to reduce anxiety of radiation

    International Nuclear Information System (INIS)

    Comparisons with other risks help to put radiation risk into perspective and facilitate communication of radiation risk to the public. More information and communication on radiation, clear behavioural guidelines in situations of increased radiation levels, and respect for citizens' concerns about radiation protection would counterbalance the publics fears and feelings of vulnerability. The use of the term radiophobia is discouraged as a description of public concerns. It is recommended that persons who appear unduly fearful of radiation should be handled with care and given professional medical treatment

  10. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    Directory of Open Access Journals (Sweden)

    E. J. Morgan

    2015-02-01

    Full Text Available A new coastal background site has been established for observations of greenhouse gases (GHGs in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA. Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS; nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS. Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a working tank.

  11. Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

    Science.gov (United States)

    Morgan, E. J.; Lavrič, J. V.; Seifert, T.; Chicoine, T.; Day, A.; Gomez, J.; Logan, R.; Sack, J.; Shuuya, T.; Uushona, E. G.; Vincent, K.; Schultz, U.; Brunke, E.-G.; Labuschagne, C.; Thompson, R. L.; Schmidt, S.; Manning, A. C.; Heimann, M.

    2015-02-01

    A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated, continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a working tank.

  12. Radiation measurements on the ''Kosmos-900'' satellite

    International Nuclear Information System (INIS)

    Considered is the design and principle of operation of differential electron spectrometers positioned on the ''Kosmos-900'' satellite. Spectrometers are intended for detection of electron of the energy from 30 to 1600 keV with the help of semiconductor diffusion-drift silicon detectors placed in bending magnet systems with angular deviation of 180 deg. Presented are preliminary results of measuring electron fluxes on the ''Kosmos'-900'' satellite orbit. Spectrometer channel calibration has been made with the help of electron and γ sources. The results of determination of spectrometer efficiency are presented. Presented also are the differential energy spectra of electrons obtained in radiation Earth belt in magnetically calm period of 7.06 1977, 03sup(n)59sup(m)-04sup(n)0Ssup(m)

  13. Research on atmospheric corrosion of steel using synchrotron radiation

    International Nuclear Information System (INIS)

    Correlation between local structure around Cr in the protective rust layer on weathering steel and protective performance of the rust layer is presented as an example of corrosion research using synchrotron radiation which has recently been applied in various research fields as a useful tool. In addition, in situ observation of initial process of rust formation on steel is also mentioned. It was pointed out by considering the X-ray absorption fine structure spectra that the nanostructure of the protective rust layer on weathering steel primarily comprises of small Cr-goethite crystals containing surface adsorbed and/or intergranular CrOx3-2X complex anions. This CrOx3-2X explains the protective performance of the rust layer originated by dense aggregation of fine crystals with cation selectivity of the Cr-goethite. It is very advantageous to employ white X-rays for in situ observation of rusting process of a carbon steel covered with electrolyte thin films because rust structure might change very quickly. This in situ observation revealed the effect of ion species on the change in rust phase during wet/dry repeating. It can be said that application of synchrotron radiation on corrosion research is so useful to understand the nanostructure of surface oxides which closely relate to corrosion behavior of metals and alloys. (author)

  14. A Thermal Infrared Radiation Parameterization for Atmospheric Studies

    Science.gov (United States)

    Chou, Ming-Dah; Suarez, Max J.; Liang, Xin-Zhong; Yan, Michael M.-H.; Cote, Charles (Technical Monitor)

    2001-01-01

    This technical memorandum documents the longwave radiation parameterization developed at the Climate and Radiation Branch, NASA Goddard Space Flight Center, for a wide variety of weather and climate applications. Based on the 1996-version of the Air Force Geophysical Laboratory HITRAN data, the parameterization includes the absorption due to major gaseous absorption (water vapor, CO2, O3) and most of the minor trace gases (N2O, CH4, CFCs), as well as clouds and aerosols. The thermal infrared spectrum is divided into nine bands. To achieve a high degree of accuracy and speed, various approaches of computing the transmission function are applied to different spectral bands and gases. The gaseous transmission function is computed either using the k-distribution method or the table look-up method. To include the effect of scattering due to clouds and aerosols, the optical thickness is scaled by the single-scattering albedo and asymmetry factor. The parameterization can accurately compute fluxes to within 1% of the high spectral-resolution line-by-line calculations. The cooling rate can be accurately computed in the region extending from the surface to the 0.01-hPa level.

  15. Alpha radiation measurement - Recommendations dossier for measurements optimization

    International Nuclear Information System (INIS)

    Used in the medical domain, in the military industry or in the electronuclear industry, the alpha radiation, by its detection and measurement, is of prime importance for the environmental control, the follow up of any industrial technical operation or the measurement of the health impact of radioactivity. This book gathers the basic knowledge, both practical and theoretical, and the necessary recommendations that any operator, technician or engineer would need to know for the use of alpha spectroscopy as a quantitative and qualitative method of analysis. It supplies information in the domains of: - sources preparation for alpha spectroscopy measurement; - measurements implementation for each technique: proportional counter, semiconductor alpha spectroscopy, grid chamber and liquid scintillation; - results processing and display; - quality assurance. It makes a synthesis of the know-how of laboratories in the fabrication of thin sources by supplying simple but important rules as well as information allowing to deal with the physical and chemical limits of thin sources. It lists the techniques relative to alpha particles detection and describes for each of them their sensitivity, advantages and drawbacks, and field of use. It introduces in the simplest as possible manner the mathematical tools needed for spectra deconvolution with some practical examples allowing to illustrate some complex situations encountered. It supplies to the user the theoretical and practical background necessary for the production of reliable and valid results. Finally, it includes and discusses the recent considerations about the calculation of decision threshold and detection limits. Content: 1 - reference documents: scientific and technical documents, standards, nuclear data; 2 - natural and artificial alpha radioactivity: discovery of alpha radiation, natural alpha radioactivity, artificial alpha radioactivity (medical, industrial exposure), dating method using nuclear phenomena; 3

  16. Response of the AMOC to reduced solar radiation – the modulating role of atmospheric-chemistry

    OpenAIRE

    Muthers, Stefan; Raible, Christoph C.; Thomas F Stocker

    2016-01-01

    The influence of reduced solar forcing (grand solar minimum or geoengineering scenarios like solar radiation management) on the Atlantic meridional overturning circulation (AMOC) is assessed in an ensemble of atmosphere-ocean-chemistry-climate model simulations. Ensemble sensitivity simulations are performed with and without interactive chemistry. Without chemistry-climate interaction the AMOC is intensified in the course of the solar radiation reduction (SRR), which is ...

  17. An atmospheric radiative-convective model with interactive water vapor transport and cloud development

    OpenAIRE

    HUMMEL, JOHN R.; KUHN, WILLIAM R.

    2011-01-01

    In the present generation of radiative-convective models, clouds are assigned specific levels or temperatures that do not change during the course of the calculations. In addition, a single water vapor distribution is used for the “mean atmosphere” instead of separate distributions for the clear sky and cloudy sky atmospheres. We present results from a one-dimensional radiative-convective model that includes interactive water vapor transport and predicts cloud altitudes and thicknesses. The ...

  18. Radiation measurement on the International Space Station.

    Science.gov (United States)

    Akopova, A B; Manaseryan, M M; Melkonyan, A A; Tatikyan, S Sh; Potapov, Yu

    2005-02-01

    The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380 km and inclination 51.6 degrees are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z > or = 2) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of dE/dx and during the last years it has already been successfully used on board the MIR station, Space Shuttles and "Kosmos" spacecrafts. An integral LET spectrum was measured in the range 0.5-2.2 x 10(3) keV/micrometers and the value of equivalent dose 360 microSv/day was estimated. The flux of biologically dangerous heavy particles with Z > or = 2 was measured (3.85 x 10(3) particles/cm2). PMID:15856556

  19. Cloud and Radiation Processes Simulated by a Coupled Atmosphere-Ocean Model

    Institute of Scientific and Technical Information of China (English)

    WANG Fang; DING Yihui; XU Ying

    2007-01-01

    Using NCC/IAP T63 coupled atmosphere-ocean general circulation model (AOGCM), two 20-yr integrations were processed, and their ability to simulate cloud and radiation was analysed in detail. The results show that the model can simulate the basic distribution of cloud cover, and however, obvious differences still exist compared with ISCCP satellite data and ERA reanalysis data. The simulated cloud cover is less in general, especially the abnormal low values in some regions of ocean. By improving the cloud cover scheme,simulated cloud cover in the eastern Pacific and Atlantic, summer hemisphere's oceans from subtropical to mid-latitude is considerably improved. But in the tropical Indian Ocean and West Pacific the cloud cover difference is still evident, mainly due to the deficiency of high cloud simulation in these regions resulting from deep cumulus convection. In terms of the analysis on radiation and cloud radiative forcing, we find that simulation on long wave radiation is better than short wave radiation. The simulation error of short wave radiation is caused mostly by the simulation difference in short wave radiative forcing, sea ice, and snow cover, and also by not involving aerosol's effect. The simulation error of long wave radiation is mainly resulting from deficiency in simulating cloud cover and underlying surface temperature. Corresponding to improvement of cloud cover, the simulated radiation (especially short wave radiation) in eastern oceans,summer hemisphere's oceans from subtropical to mid-latitude is remarkably improved. This also bring sobvious improvement to net radiation in these regions.

  20. Absolute high spectral resolution measurements of surface solar radiation for detection of water vapour continuum absorption.

    Science.gov (United States)

    Gardiner, T D; Coleman, M; Browning, H; Tallis, L; Ptashnik, I V; Shine, K P

    2012-06-13

    Solar-pointing Fourier transform infrared (FTIR) spectroscopy offers the capability to measure both the fine scale and broadband spectral structure of atmospheric transmission simultaneously across wide spectral regions. It is therefore suited to the study of both water vapour monomer and continuum absorption behaviours. However, in order to properly address this issue, it is necessary to radiatively calibrate the FTIR instrument response. A solar-pointing high-resolution FTIR spectrometer was deployed as part of the 'Continuum Absorption by Visible and Infrared radiation and its Atmospheric Relevance' (CAVIAR) consortium project. This paper describes the radiative calibration process using an ultra-high-temperature blackbody and the consideration of the related influence factors. The result is a radiatively calibrated measurement of the solar irradiation at the ground across the IR region from 2000 to 10 000 cm(-1) with an uncertainty of between 3.3 and 5.9 per cent. This measurement is shown to be in good general agreement with a radiative-transfer model. The results from the CAVIAR field measurements are being used in ongoing studies of atmospheric absorbers, in particular the water vapour continuum. PMID:22547234

  1. Electron Density and Temperature Measurements, and Abundance Anomalies in the Solar Atmosphere

    Indian Academy of Sciences (India)

    Anita Mohan; Bhola N. Dwivedi; Enrico Landi

    2000-09-01

    Using spectra obtained from the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) spectrograph on the spacecraft SOHO (Solar and Heliospheric Observatory), we investigate the height dependence of electron density, temperature and abundance anomalies in the solar atmosphere. In particular, we present the behaviour of the solar FIP effect (the abundance enhancement of elements with first ionization potential < 10 eV in the corona with respect to photospheric values) with height above an active region observed at the solar limb, with emphasis on the so-called transition region lines.

  2. Atmospheric Temperature Profile Measurements Using Mobile High Spectral Resolution Lidar

    Science.gov (United States)

    Razenkov, Ilya I.; Eloranta, Edwin W.

    2016-06-01

    The High Spectral Resolution Lidar (HSRL) designed at the University of Wisconsin-Madison discriminates between Mie and Rayleigh backscattering [1]. It exploits the Doppler effect caused by thermal motion of molecules, which broadens the spectrum of the transmitted laser light. That allows for absolute calibration of the lidar and measurements of the aerosol volume backscatter coefficient. Two iodine absorption filters with different absorption line widths (a regular iodine vapor filter and Argon buffered iodine filter) allow for atmospheric temperature profile measurements. The sensitivity of the measured signal-to-air temperature ratio is around 0.14%/K. The instrument uses a shared telescope transmitter-receiver design and operates in eyesafe mode (the product of laser average power and telescope aperture equals 0.1 Wm2 at 532 nm).

  3. Atmospheric Temperature Profile Measurements Using Mobile High Spectral Resolution Lidar

    Directory of Open Access Journals (Sweden)

    Razenkov Ilya I.

    2016-01-01

    Full Text Available The High Spectral Resolution Lidar (HSRL designed at the University of Wisconsin-Madison discriminates between Mie and Rayleigh backscattering [1]. It exploits the Doppler effect caused by thermal motion of molecules, which broadens the spectrum of the transmitted laser light. That allows for absolute calibration of the lidar and measurements of the aerosol volume backscatter coefficient. Two iodine absorption filters with different absorption line widths (a regular iodine vapor filter and Argon buffered iodine filter allow for atmospheric temperature profile measurements. The sensitivity of the measured signal-to-air temperature ratio is around 0.14%/K. The instrument uses a shared telescope transmitter-receiver design and operates in eyesafe mode (the product of laser average power and telescope aperture equals 0.1 Wm2 at 532 nm.

  4. Comparing radial velocities of atmospheric lines with radiosonde measurements

    CERN Document Server

    Figueira, P; Chacon, A; Lovis, C; Santos, N C; Curto, G Lo; Sarazin, M; Pepe, F

    2011-01-01

    The precision of radial velocity (RV) measurements depends on the precision attained on the wavelength calibration. One of the available options is using atmospheric lines as a natural, freely available wavelength reference. Figueira et al. (2010) measured the RV of O2 lines using HARPS and showed that the scatter was only of ~10 m/s over a timescale of 6 yr. Using a simple but physically motivated empirical model, they demonstrated a precision of 2 m/s, roughly twice the average photon noise contribution. In this paper we take advantage of a unique opportunity to confirm the sensitivity of the telluric absorption lines RV to different atmospheric and observing conditions: by means of contemporaneous in-situ wind measurements by radiosondes. The RV model fitting yielded similar results to that of Figueira et al. (2010), with lower wind magnitude values and varied wind direction. The probes confirmed the average low wind magnitude and suggested that the average wind direction is a function of time as well. The...

  5. An Iterative Phase-Space Explicit Discontinuous Galerkin Method for Stellar Radiative Transfer in Extended Atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    de Almeida, V.F.

    2004-01-28

    A phase-space discontinuous Galerkin (PSDG) method is presented for the solution of stellar radiative transfer problems. It allows for greater adaptivity than competing methods without sacrificing generality. The method is extensively tested on a spherically symmetric, static, inverse-power-law scattering atmosphere. Results for different sizes of atmospheres and intensities of scattering agreed with asymptotic values. The exponentially decaying behavior of the radiative field in the diffusive-transparent transition region and the forward peaking behavior at the surface of extended atmospheres were accurately captured. The integrodifferential equation of radiation transfer is solved iteratively by alternating between the radiative pressure equation and the original equation with the integral term treated as an energy density source term. In each iteration, the equations are solved via an explicit, flux-conserving, discontinuous Galerkin method. Finite elements are ordered in wave fronts perpendicularly to the characteristic curves so that elemental linear algebraic systems are solved quickly by sweeping the phase space element by element. Two implementations of a diffusive boundary condition at the origin are demonstrated wherein the finite discontinuity in the radiative intensity is accurately captured by the proposed method. This allows for a consistent mechanism to preserve photon luminosity. The method was proved to be robust and fast, and a case is made for the adequacy of parallel processing. In addition to classical two-dimensional plots, results of normalized radiative intensity were mapped onto a log-polar surface exhibiting all distinguishing features of the problem studied.

  6. RF impedance measurements of DC atmospheric micro-discharges

    CERN Document Server

    Overzet, Lawrence J; Mandra, Monali; Goeckner, Matthew; Dufour, Thierry; Dussart, Remi; Lefaucheux, Philippe

    2016-01-01

    The available diagnostics for atmospheric micro-plasmas remain limited and relatively complex to implement; so we present a radio-frequency technique for diagnosing a key parameter here. The technique allows one to estimate the dependencies of the electron density by measuring the RF-impedance of the micro-plasma and analyzing it with an appropriate equivalent circuit. This technique is inexpensive, can be used in real time and gives reasonable results for argon and helium DC micro-plasmas in holes over a wide pressure range. The electron density increases linearly with current in the expected range consistent with normal glow discharge behavior.

  7. Modulation in Ocean Primary Production due to Variability of Photosynthetically Available Radiation under Different Atmospheric Conditions

    Directory of Open Access Journals (Sweden)

    Madhumita Tripathy

    2014-01-01

    Full Text Available The rate of photosynthesis primarily depends on nutrients and photosynthetically available radiation (PAR at sea surface. Several ship cruises were carried out to measure optical, biological, and atmospheric parameters in the Arabian Sea and their variability were studied. An analytical nonspectral photosynthesis-irradiance model was used to estimate euphotic primary production (EuPP to study its variability during cruise periods. PAR was estimated using COART model using in situ measured aerosol optical depth (AOD to compare with in situ measured PAR. In order to understand the variability of PAR under different types of aerosol and different aerosol loading, a simulation study was carried out using COART model. EuPP was estimated for various PAR values under different aerosol loading and cloud coverage conditions. Sensitivity analysis showed that for maritime, maritime polluted, and desert aerosols, the ratio PAR/PAR0AOD has attenuated to about 11–25%, whereas it has attenuated to 44% for urban aerosol type. PAR/PARclear  sky was reduced by ~57% for high aerosol loading and for overcast sky. The decrease in EuPP under various aerosol loading and cloud coverage was observed to depend on the photoadaptation parameter. EuPP/EuPPclear  sky was reduced by 38% for maximum maritime aerosol loading and for overcast sky.

  8. A New Laser Based Approach for Measuring Atmospheric Greenhouse Gases

    Directory of Open Access Journals (Sweden)

    Jeremy Dobler

    2013-11-01

    Full Text Available In 2012, we developed a proof-of-concept system for a new open-path laser absorption spectrometer concept for measuring atmospheric CO2. The measurement approach utilizes high-reliability all-fiber-based, continuous-wave laser technology, along with a unique all-digital lock-in amplifier method that, together, enables simultaneous transmission and reception of multiple fixed wavelengths of light. This new technique, which utilizes very little transmitted energy relative to conventional lidar systems, provides high signal-to-noise (SNR measurements, even in the presence of a large background signal. This proof-of-concept system, tested in both a laboratory environment and a limited number of field experiments over path lengths of 680 m and 1,600 m, demonstrated SNR values >1,000 for received signals of ~18 picoWatts averaged over 60 s. A SNR of 1,000 is equivalent to a measurement precision of ±0.001 or ~0.4 ppmv. The measurement method is expected to provide new capability for automated monitoring of greenhouse gas at fixed sites, such as carbon sequestration facilities, volcanoes, the short- and long-term assessment of urban plumes, and other similar applications. In addition, this concept enables active measurements of column amounts from a geosynchronous orbit for a network of ground-based receivers/stations that would complement other current and planned space-based measurement capabilities.

  9. Investigation of atmospheric diffusion by immission measurements of xenon-133 from Fessenheim nuclear power station

    International Nuclear Information System (INIS)

    The atmospheric xenon radioactivity was measured from mid 1983 to the end of 1984 in the surroundings of Fessenheim nuclear power station on the right bank of the Rhine. The level of activity (annual mean at Hartheim 1.6 pCi/m3 against a background of about 0.2 pCi/m3) makes it possible to carry out a diffusion study. Using a one-dimensional Gauss model, expected values of immission were calculated, taking into account the average strength of the source. Radiation balance, degree of cover or global radiation/degree of cover and wind speed, were used as parameters for atmospheric stability. The agreement between the calculated and measured immission based on weekly averages is satisfactory: about 2/3 of all calculated immissions deviate by less than a factor of 3.5 from the measured values. The accuracy of prediction of the model rises for longer averaging periods; for three months averaging, there is a factor of 1.5 deviation. The drop in concentration between the stations at different distances from the source is predicted too steeply by a factor of 1.5 by the model. (orig.)

  10. Investigation of atmospheric diffusion by immission measurements of xenon-133 from Fessenheim nuclear power station

    International Nuclear Information System (INIS)

    The atmospheric xenon radioactivity was measured from mid 1983 to the end of 1984 in the surroundings of Fessenheim nuclear power station on the right bank of the Rhine. The level of activity (annual mean at Hartheim 1.6 pCi/m3 against a background of about 0.2 pCi/m3) makes it possible to carry out a diffusion study. Using a one-dimensional Gauss model, expected values of immission were calculated, taking into account the average strength of the source. Radiation balance, degree of cover or global radiation/ degree of cover and wind speed, were used as parameters for atmospheric stability. The agreement between the calculated and measured immission based on weekly averages is satisfactory: about 2/3 of all calculated immissions deviate by less than a factor of 3.5 from the measured values. The accuracy of prediction of the model rises for longer averaging periods; for three months averaging, there is a factor of 1.5 deviation. The drop in concentration between the stations at different distances from the source is predicted too steeply by a factor of 1.5 by the model. (orig./HP)

  11. Failure and Redemption of Multifilter Rotating Shadowband Radiometer (MFRSR/Normal Incidence Multifilter Radiometer (NIMFR Cloud Screening: Contrasting Algorithm Performance at Atmospheric Radiation Measurement (ARM North Slope of Alaska (NSA and Southern Great Plains (SGP Sites

    Directory of Open Access Journals (Sweden)

    James Barnard

    2013-09-01

    Full Text Available Well-known cloud-screening algorithms, which are designed to remove cloud-contaminated aerosol optical depths (AOD from Multifilter Rotating Shadowband Radiometer (MFRSR and Normal Incidence Multifilter Radiometer (NIMFR measurements, have exhibited excellent performance at many middle-to-low latitude sites around world. However, they may occasionally fail under challenging observational conditions, such as when the sun is low (near the horizon and when optically thin clouds with small spatial inhomogeneity occur. Such conditions have been observed quite frequently at the high-latitude Atmospheric Radiation Measurement (ARM North Slope of Alaska (NSA sites. A slightly modified cloud-screening version of the standard algorithm is proposed here with a focus on the ARM-supported MFRSR and NIMFR data. The modified version uses approximately the same techniques as the standard algorithm, but it additionally examines the magnitude of the slant-path line of sight transmittance and eliminates points when the observed magnitude is below a specified threshold. Substantial improvement of the multi-year (1999–2012 aerosol product (AOD and its Angstrom exponent is shown for the NSA sites when the modified version is applied. Moreover, this version reproduces the AOD product at the ARM Southern Great Plains (SGP site, which was originally generated by the standard cloud-screening algorithms. The proposed minor modification is easy to implement and its application to existing and future cloud-screening algorithms can be particularly beneficial for challenging observational conditions.

  12. Inversion of Atmospheric Tracer Measurements, Localization of Sources

    Science.gov (United States)

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

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

  13. Microdosimetric measurements for radiotherapy and radiation protection

    International Nuclear Information System (INIS)

    Neutrons produced by bombarding a 4 mm thick beryllium target with deuterons of 30 MeV and 70 MeV proton beams are used for a clinical trials of radiotherapy in NIRS cyclotron facility. Microdosimetric measurements for neutrons and protons were carried out using a tissue-equivalent (TE) proportional counters, and LET-1/2-SW counter and LET-5-SW counter. The TE gas employed is the propane based mixture, and pressure of 67.7 torr provided an effective sphere diameter of 2 μm for LET-1/2-SW counter. Alpha particles emitted from Cm-244 have an energy of approximatey 5.8 MeV, and the energy loss in a 2 μm path length of propane based TE gas was calculated to be 79.2 keV/μm. For the improvement of S/N ratio, a probetype charge sensitive pre-amplifier built in a first stage FET was used. Electronic signals were amplified and processed with a homemade spectroscopy logarithmic amplifier and a multichannel analyzer. The logarithmic amplifier made it possible to measure the dose distributions in lineal energy from less than 50 eV/μm to 2000 keV/μm at the same time. The number of pulse as a function of lineal energy in logarithm was stored and then processed with a personal computer (PC-9801). The measurement were also made on mixed radiation fields of neutron and proton and gamma-rays in order to investigate the variation of dose distribution in lineal energy. The differential distribution of dose in lineal energy, d(y) = y·n(y) was normalized to yield the fraction of dose deposited per unit of lineal energy. On the basis of these distributions, the dose-averaged LET and the average quality factor for radiations outside the primary beams was determined by using calculated with separately d(y)-distribution of a Photon fields. (author)

  14. 40 CFR Appendix D to Part 50 - Measurement Principle and Calibration Procedure for the Measurement of Ozone in the Atmosphere

    Science.gov (United States)

    2010-07-01

    ... Procedure for the Measurement of Ozone in the Atmosphere D Appendix D to Part 50 Protection of Environment... Measurement of Ozone in the Atmosphere Measurement Principle 1. Ambient air and ethylene are delivered... atmospheres l = optical path length in cm In practice, a stable O3 generator is used to produce...

  15. Gamma radiation measurements in Brazilian commercial granites

    International Nuclear Information System (INIS)

    Full text of publication follows: Gamma radiation from radionuclides which are characterized by half lives comparable to the age of the earth, such as 40 K and the radionuclides from the 238 U and 232 Th series, and their decay products, represent the main terrestrial source of irradiation to the human body. Their concentrations vary for different types of rocks, where high radiation levels are associated with igneous rocks such as granite. Thorium, uranium and potassium concentrations of granitic rocks are intimately related to their mineral compositions and general petrologic features. Then, these features associated with effects of weathering and metamorphism produce expressive alterations in the relationship between the natural radionuclides (Th, U, K, Th/U and Th/K). Consequently, the measurements of thorium, uranium, and potassium concentrations of different granite samples result on individual differentiation sequences. From the 232 Th, 238 U and 40 K activity concentrations obtained for each sample, it is possible to evaluate their respective dose rates in air, when these stones are used as tiling rocks. These results are of great interest in the environmental radiological protection study, since granites are widely used as building and ornamental materials, including as indoor covering. In this way, the Laboratory of Radioecology (L.A.R.A.) of the Physics Institute of the Universidade Federal Fluminense (I.F. -U.F.F.) has been performing analyzes on more than one hundred differ ent types of the main Brazilian commercial granites in last two years [1]. Using NaI and HP Ge gamma-ray spectrometers to determine the concentration of natural radionuclides in these samples, the annual effective dose rates and the gamma activity concentration index have been evaluated and compared to the limits proposed by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and European Commission (E.C.). In addition, the correlations between thorium

  16. Fourier Transform Spectrometer measurements of Atmospheric Carbon Dioxide and Methane

    Science.gov (United States)

    Kivi, Rigel; Heikkinen, Pauli; Chen, Huilin; Hatakka, Juha; Laurila, Tuomas

    2016-04-01

    Ground based remote sensing measurements of column CO2 and CH4 using Fourier Transform Spectrometers (FTS) within the Total Carbon Column Observing Network (TCCON) are known for high precision and accuracy. These measurements are performed at various locations globally and they have been widely used in carbon cycle studies and validation of space born measurements. The relevant satellite missions include the Orbiting Carbon Observatory-2 (OCO-2) by the National Aeronautics and Space Administration (NASA); the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) by the European Space Agency (ESA); the Greenhouse gases Observing SATellite (GOSAT) by the Japan Aerospace Exploration Agency (JAXA) and the upcoming Sentinel-5 Precursor mission, which is an ESA mission and scheduled for launch in 2016. Results of the column CO2 and CH4 measurements at Sodankylä in northern Finland (at 67.4° N, 26.6° E) are reported in this study. The measurements have been performed on regular basis since the beginning of the program in early 2009. We also present evaluation of the data quality of the ground based measurements and comparisons with the available satellite based retrievals. In case of comparisons between the GOSAT and ground based retrievals of CO2 and CH4 no significant biases were found. Sodankylä is one of the northernmost stations in the TCCON network. However, the data coverage has been relatively good thanks to the progress towards automation of the FTS measurement system. At Sodankylä the retrievals have been also compared with the balloon borne AirCore measurements at the site. AirCore sampling system is directly related to the World Meteorological Organization in situ trace gas measurement scales. The balloon platform allows sampling in both stratosphere and troposphere, which is a benefit, compared to the aircraft in situ measurements.

  17. Four Numerical Approaches for Solving the Radiative Transfer Equation in Magnetized White-Dwarf Atmospheres

    OpenAIRE

    Jordan, Stefan; Schmidt, Holger

    2003-01-01

    We compare four different methods to calculate radiative transfer through a magnetized stellar atmosphere, and apply them to the case of magnetic white dwarfs. All methods are numerically stable enough to allow determination of the magnetic field structure, but distinctions between faster, simplifying, methods, and elaborate, but more CPU-time consuming, methods, can be made.

  18. Bayesian Atmospheric Radiative Transfer (BART) Code and Application to WASP-43b

    Science.gov (United States)

    Blecic, Jasmina; Harrington, Joseph; Cubillos, Patricio; Bowman, Oliver; Rojo, Patricio; Stemm, Madison; Lust, Nathaniel B.; Challener, Ryan; Foster, Austin James; Foster, Andrew S.; Blumenthal, Sarah D.; Bruce, Dylan

    2016-01-01

    We present a new open-source Bayesian radiative-transfer framework, Bayesian Atmospheric Radiative Transfer (BART, https://github.com/exosports/BART), and its application to WASP-43b. BART initializes a model for the atmospheric retrieval calculation, generates thousands of theoretical model spectra using parametrized pressure and temperature profiles and line-by-line radiative-transfer calculation, and employs a statistical package to compare the models with the observations. It consists of three self-sufficient modules available to the community under the reproducible-research license, the Thermochemical Equilibrium Abundances module (TEA, https://github.com/dzesmin/TEA, Blecic et al. 2015}, the radiative-transfer module (Transit, https://github.com/exosports/transit), and the Multi-core Markov-chain Monte Carlo statistical module (MCcubed, https://github.com/pcubillos/MCcubed, Cubillos et al. 2015). We applied BART on all available WASP-43b secondary eclipse data from the space- and ground-based observations constraining the temperature-pressure profile and molecular abundances of the dayside atmosphere of WASP-43b. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G. JB holds a NASA Earth and Space Science Fellowship.

  19. Atmospheric Aerosol Attenuation Measurements at the Pierre Auger Observatory

    CERN Document Server

    Valore, Laura

    2014-01-01

    The Fluorescence Detector (FD) of the Pierre Auger Observatory provides a nearly calorimetric measurement of the primary particle energy, since the fluorescence light produced is proportional to the energy dissipated by an Extensive Air Shower (EAS) in the atmosphere. The atmosphere therefore acts as a giant calorimeter, whose properties need to be well known during data taking. Aerosols play a key role in this scenario, since their effect on light transmission is highly variable even on a time scale of one hour, and the corresponding correction to EAS energy can range from a few percent to more than 40%. For this reason, hourly Vertical Aerosol Optical Depth (taer(h)) profiles are provided for each of the four FD stations. Starting from 2004, up to now 9 years of taer(h) profiles have been produced using data from the Central Laser Facility (CLF) and the eXtreme Laser Facility (XLF) of the Pierre Auger Observatory. The two laser facilities, the techniques developed to measure taer(h) profiles using laser dat...

  20. Radiation detection and measurement concepts, methods and devices

    CERN Document Server

    McGregor, Douglas

    2017-01-01

    This text on radiation detection and measurement is a response to numerous requests expressed by students at various universities, in which the most popularly used books do not provide adequate background material, nor explain matters in understandable terms. This work provides a modern overview of radiation detection devices and radiation measurement methods. The topics selected in the book have been selected on the basis of the author’s many years of experience designing radiation detectors and teaching radiation detection and measurement in a classroom environment.

  1. Further considerations of cosmic ray modulation of infra-red radiation in the atmosphere

    CERN Document Server

    Aplin, Karen

    2015-01-01

    Understanding effects of ionisation in the lower atmosphere is a new interdisciplinary area, crossing traditionally distinct scientific boundaries. Following the paper of Erlykin et al. (Astropart. Phys. 57--58 (2014) 26--29) we develop the interpretation of observed changes in long-wave (LW) radiation (Aplin and Lockwood, Env. Res. Letts. 8, 015026 (2013)), by taking account of cosmic ray ionisation yields and atmospheric radiative transfer. To demonstrate this, we show that the thermal structure of the whole atmosphere needs to be considered along with the vertical profile of ionisation. Allowing for ionisation by all components of a cosmic ray shower and not just by the muons, reveals that the effect we have detected is certainly not inconsistent with laboratory observations of the LW absorption cross section. The analysis presented here, although very different from that of Erlykin et al., does come to the same conclusion that the events detected were not caused by individual cosmic ray primaries -- not b...

  2. Analytical Models of Exoplanetary Atmospheres. II. Radiative Transfer via the Two-Stream Approximation

    CERN Document Server

    Heng, Kevin; Lee, Jaemin

    2014-01-01

    We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and solutions describing two-stream radiative transfer (which approximates the passage of radiation as a pair of outgoing and incoming fluxes), flux-limited diffusion (which describes radiative transfer in the deep interior) and solutions for the temperature-pressure profiles. Generally, the problem is mathematically under-determined unless a set of closures (Eddington coefficients) is specified. We demonstrate that the hemispheric (or hemi-isotropic) closure naturally derives from the radiative transfer equation if energy conservation is obeyed, while the Eddington closure produces spurious enhancements of both reflected light and thermal emission. We further demonstrate that traditional non-isothermal treatments of each atmospheric layer lead to unphysical contributions to the ...

  3. Non-linear Evolution of Rayleigh-Taylor Instability in a Radiation Supported Atmosphere

    CERN Document Server

    Jiang, Yan-Fei; Stone, James

    2012-01-01

    The non-linear regime of Rayleigh-Taylor instability (RTI) in a radiation supported atmosphere, consisting of two uniform fluids with different densities, is studied numerically. We perform simulations using our recently developed numerical algorithm for multi-dimensional radiation hydrodynamics based on a variable Eddington tensor as implemented in Athena, focusing on the regime where scattering opacity greatly exceeds absorption opacity. We find that the radiation field can reduce the growth and mixing rate of RTI, but this reduction is only significant when radiation pressure significantly exceeds gas pressure. Small scale structures are also suppressed in this case. In the non-linear regime, dense fingers sink faster than rarefied bubbles can rise, leading to asymmetric structures about the interface. By comparing the calculations that use a variable Eddington tensor (VET) versus the Eddington approximation, we demonstrate that anisotropy in the radiation field can affect the non-linear development of RTI...

  4. Atmospheric sulphuric acid and aerosol formation: implications from atmospheric measurements for nucleation and early growth mechanisms

    Directory of Open Access Journals (Sweden)

    S.-L. Sihto

    2006-01-01

    Full Text Available We have investigated the formation and early growth of atmospheric secondary aerosol particles building on atmospheric measurements. The measurements were part of the QUEST 2 campaign which took place in spring 2003 in Hyytiälä (Finland. During the campaign numerous aerosol particle formation events occurred of which 15 were accompanied by gaseous sulphuric acid measurements. Our detailed analysis of these 15 events is focussed on nucleation and early growth (to a diameter of 3 nm of fresh particles. It revealed that new particle formation seems to be a function of the gaseous sulphuric acid concentration to the power from one to two when the time delay between the sulphuric acid and particle number concentration is taken into account. From the time delay the growth rates of freshly nucleated particles from 1 nm to 3 nm were determined. The mean growth rate was 1.2 nm/h and it was clearly correlated with the gaseous sulphuric acid concentration. We tested two nucleation mechanisms – recently proposed cluster activation and kinetic type nucleation – as possible candidates to explain the observed dependences, and determined experimental nucleation coefficients. We found that some events are dominated by the activation mechanism and some by the kinetic mechanism. Inferred coefficients for the two nucleation mechanisms are the same order of magnitude as chemical reaction coefficients in the gas phase and they correlate with the product of gaseous sulphuric acid and ammonia concentrations. This indicates that besides gaseous sulphuric acid also ammonia has a role in nucleation.

  5. Radiation power measurement on the ADITYA tokamak

    Science.gov (United States)

    Tahiliani, Kumudni; Jha, Ratneshwar; Gopalkrishana, M. V.; Doshi, Kalpesh; Rathod, Vipal; Hansalia, Chandresh; ADITYA Team

    2009-08-01

    The radiation power loss and its variation with plasma density and current are studied in the ADITYA tokamak. The radiation power loss varies from 20% to 40% of the input power for different discharges. The radiation fraction decreases with increasing plasma current but it increases with increasing line-averaged central density. The radiated power behavior has also been studied in discharges with short pulses of molecular beam injection (MBI) and gas puff (GP). The increase in radiation loss is limited to the edge chords in the case of GP, but it extends to the core region for MBI fueling. The MBI seems to indicate reduction in the edge recycling. It is observed that during the density limit disruption, the radiated power loss is more in the current quench phase as compared with the thermal quench phase and comes mainly from the plasma edge.

  6. Evaluation and application of passive and active optical remote sensing methods for the measurement of atmospheric aerosol properties

    Energy Technology Data Exchange (ETDEWEB)

    Mielonen, T.

    2010-07-01

    Atmospheric aerosol particles affect the atmosphere's radiation balance by scattering and absorbing sunlight. Moreover, the particles act as condensation nuclei for clouds and affect their reflectivity. In addition, aerosols have negative health effects and they reduce visibility. Aerosols are emitted into the atmosphere from both natural and anthropogenic sources. Different types of aerosols have different effects on the radiation balance, thus global monitoring and typing of aerosols is of vital importance. In this thesis, several remote sensing methods used in the measurement of atmospheric aerosols are evaluated. Remote sensing of aerosols can be done with active and passive instruments. Passive instruments measure radiation emitted by the sun and the Earth while active instruments have their own radiation source, for example a black body radiator or laser. The instruments utilized in these studies were sun photometers (PFR, Cimel), lidars (POLLYXT, CALIOP), transmissiometer (OLAF) and a spectroradiometer (MODIS). Retrieval results from spaceborne instruments (MODIS, CALIOP) were evaluated with ground based measurements (PFR, Cimel). In addition, effects of indicative aerosol model assumptions on the calculated radiative transfer were studied. Finally, aerosol particle mass at the ground level was approximated from satellite measurements and vertical profiles of aerosols measured with a lidar were analyzed. For the evaluation part, these studies show that the calculation of aerosol induced attenuation of radiation based on aerosol size distribution measurements is not a trivial task. In addition to dry aerosol size distribution, the effect of ambient relative humidity on the size distribution and the optical properties of the aerosols need to be known in order to achieve correct results from the calculations. Furthermore, the results suggest that aerosol size parameters retrieved from passive spaceborne measurements depend heavily on surgace reflectance

  7. Modeling radiation from the atmosphere of Io with Monte Carlo methods

    Science.gov (United States)

    Gratiy, Sergey

    Conflicting observations regarding the dominance of either sublimation or volcanism as the source of the atmosphere on Io and disparate reports on the extent of its spatial distribution and the absolute column abundance invite the development of detailed computational models capable of improving our understanding of Io's unique atmospheric structure and origin. To validate a global numerical model of Io's atmosphere against astronomical observations requires a 3-D spherical-shell radiative transfer (RT) code to simulate disk-resolved images and disk-integrated spectra from the ultraviolet to the infrared spectral region. In addition, comparison of simulated and astronomical observations provides important information to improve existing atmospheric models. In order to achieve this goal, a new 3-D spherical-shell forward/backward photon Monte Carlo code capable of simulating radiation from absorbing/emitting and scattering atmospheres with an underlying emitting and reflecting surface was developed. A new implementation of calculating atmospheric brightness in scattered sunlight is presented utilizing the notion of an "effective emission source" function. This allows for the accumulation of the scattered contribution along the entire path of a ray and the calculation of the atmospheric radiation when both scattered sunlight and thermal emission contribute to the observed radiation---which was not possible in previous models. A "polychromatic" algorithm was developed for application with the backward Monte Carlo method and was implemented in the code. It allows one to calculate radiative intensity at several wavelengths simultaneously, even when the scattering properties of the atmosphere are a function of wavelength. The application of the "polychromatic" method improves the computational efficiency because it reduces the number of photon bundles traced during the simulation. A 3-D gas dynamics model of Io's atmosphere, including both sublimation and volcanic

  8. The role of VUV radiation in the inactivation of bacteria with an atmospheric pressure plasma jet

    CERN Document Server

    Schneider, Simon; Ellerweg, Dirk; Denis, Benjamin; Narberhaus, Franz; Bandow, Julia E; Benedikt, Jan

    2011-01-01

    A modified version of a micro scale atmospheric pressure plasma jet (\\mu-APPJ) source, so-called X-Jet, is used to study the role of plasma generated VUV photons in the inactivation of E. coli bacteria. The plasma is operated in He gas or a He/O2 mixture and the X-Jet modification of the jet geometry allows effective separation of heavy reactive particles (such as O atoms or ozone molecules) from the plasma-generated photons. The measurements of the evolution of zone of inhibitions formed in monolayers of vegetative E. coli bacteria, of VUV emission intensity and of positive ion spectra show that photochemistry in the gas phase followed by photochemistry products impacting on bacteria can result in bacterial inactivation. Interestingly, this process is more effective than direct inactivation by VUV radiation damage. Mainly protonated water cluster ions are detected by mass spectrometry indicating that water impurity has to be carefully considered. The measurements indicate that the combination of the presence...

  9. Electromagnetically driven radiative shocks and their measurements

    International Nuclear Information System (INIS)

    Experimental results on a generation of strong shocks in a compact pulse power device are reported. The characteristics of strong shocks are different from hydrodynamical shocks' because they depend on not only collisions but radiation processes. Radiative shocks are relevant to high energy density phenomena such as the explosions of supernovae. When initial pressure is lower than about 50 mtorr, an interesting structure is confirmed at the shock front, which might indicate a phenomenon proceeded by the radiative process. (author)

  10. Determination of the radiative heating rates of dust over West Africa and their impact on the atmospherical dynamics using satellite observations during the AMMA campaign

    OpenAIRE

    Lemaître, Cyndie

    2010-01-01

    The work carried out in this study is devoted to a better understanding of radiative properties for dust in the shortwave (SW) and in the longwave (LW), and also the consequence of this radiative forcing on the atmospheric dynamics. Such a characterization is indeed essential in particular over North of Africa, the main source of mineral aerosols. Our study is based on a synergy between different platforms : in situ ground-based or airborne measurements, together with remote sensing observati...

  11. Infrared measurements in the Arctic using two Atmospheric Emitted Radiance Interferometers

    Directory of Open Access Journals (Sweden)

    Z. Mariani

    2012-02-01

    Full Text Available The Extended-range Atmospheric Emitted Radiance Interferometer (E-AERI is a moderate resolution (1 cm−1 Fourier transform infrared spectrometer for measuring the absolute downwelling infrared spectral radiance from the atmosphere between 400 and 3000 cm−1. The extended spectral range of the instrument permits monitoring of the 400–550 cm−1 (20–25 μm region, where most of the infrared surface cooling currently occurs in the dry air of the Arctic. Spectra from the E-AERI have the potential to provide information about radiative balance, trace gases, and cloud properties in the Canadian high Arctic. Calibration, performance evaluation, and certification of the E-AERI were performed at the University of Wisconsin Space Science and Engineering Centre from September to October 2008. The instrument was then installed at the Polar Environment Atmospheric Research Laboratory (PEARL Ridge Lab (610 m altitude at Eureka, Nunavut, in October 2008, where it acquired one year of data. Measurements are taken every seven minutes year-round, including polar night when the solar-viewing spectrometers at PEARL are not operated. A similar instrument, the University of Idaho's Polar AERI (P-AERI, was installed at the Zero-altitude PEARL Auxiliary Laboratory (0PAL, 15 km away from the PEARL Ridge Lab, from March 2006 to June 2009. During the period of overlap, these two instruments provided calibrated radiance measurements from two altitudes. A fast line-by-line radiative transfer model is used to simulate the downwelling radiance at both altitudes; the largest differences (simulation-measurement occur in spectral regions strongly influenced by atmospheric temperature and/or water vapour. The two AERI instruments at close proximity but located at two different altitudes are well-suited for investigating cloud forcing. As an example, it is shown that a thin, low ice cloud resulted in a 6% increase in irradiance. The presence

  12. Analysis of atmospheric aerosols by PIXE: the importance of real time and complementary measurements

    International Nuclear Information System (INIS)

    Particle-Induced X-ray Emission (PIXE) has been used for more than 30 yr in many urban and background air pollution studies. The technique has certainly contributed to the understanding of source-receptor relationship for aerosol particles as well as to aerosol physics and chemistry. In the last few years, where aerosol issues were strongly linked to global climate change through the relationship between aerosol and atmospheric radiation points to new challenges in atmospheric sciences, where PIXE could play an important role. Also the recognition for the inter-relationship between aerosol and liquid and gas phases in the atmosphere makes important to integrate PIXE aerosol analysis with other complementary measurements. The use of Nephelometers and Aethalometers to measure scattering and absorption of radiation by aerosol particles can be done in parallel with particle filter collection for PIXE analysis. Parallel measurements of trace gases using traditional monitors as well as with new techniques such as Differential Optical Absorption Spectroscopy (DOAS) that can provide concentration of O3, SO2, NO3, NO2, HCHO, HNO3, Benzene, Toluene, and Xylene, is also important for both urban and remote aerosol studies. They provide information that allows a much richer interpretation of PIXE data. Recently developed instruments that provide real time aerosol data such as the Tapered Element Oscillating Microbalance (TEOM) PM10 monitor and automatic real time organic and elemental carbon analyzers provide extremely useful data to complement PIXE aerosol analysis. The concentrations of trace elements measured by PIXE comprise only 10-30% of the aerosol mass, leaving the organic aerosol characterization and measurement with an important role. The aerosol source apportionment provided by PIXE analysis can be extended with other aerosol measurements such as scattering and absorption, estimating for example, the radiative impact of each discriminated aerosol source. The aerosol

  13. Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Osterhuber, R. [Univ. of California, Soda Springs, CA (United States). Central Sierra Snow Lab.; Fehrke, F. [California Dept. of Water Resources, Sacramento, CA (United States); Condreva, K. [Sandia National Labs., Livermore, CA (United States)

    1998-05-01

    Incoming, background cosmic radiation constantly fluxes through the earth`s atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters` worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location.

  14. Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

    International Nuclear Information System (INIS)

    Incoming, background cosmic radiation constantly fluxes through the earth's atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters' worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location

  15. New standards for ionizing radiation measurements

    International Nuclear Information System (INIS)

    The Ionizing Radiation Division has developed new national standards for mammographic X rays and for brachytherapy sources, such as iodine-125. The Attix chamber, a variable volume free-air ionization chamber, has been established as the primary national standard for mammographic X rays. The Attix chamber resides in the newly developed NIST Mammography Calibration Range and will be used to perform routine calibrations. The wide-angle free-air ionization chamber utilizes a large volume and a novel electric field configuration in order to circumvent the limitations of conventional free-air chambers. Seventeen beam qualities for X rays from molybdenum (Mo) and rhodium (Rh) anodes have been parameterized for the calibration of mammographic ionization chambers. The beam qualities available include anode/filter combinations of Mo/Mo, Mo/Rh and Rh/Rh. The mammography range was developed in collaborations with the U.S. Food and Drug Administration's (FDA) Center for Devices and Radiological Health, the implementors of the Mammography Quality Standards Act (MQSA) of 1992. The wide-angle free-air ionization chamber has been used to measure the output of two types of iodine-125 seeds, those with resin balls and those with silver wire. Both free-air chambers have been intercompared with the Ritz parallel-plate free-air ionization chamber

  16. Radiation measurements on the ''Kosmos-900'' satellite

    International Nuclear Information System (INIS)

    Presented are the experiment description and preliminary results of measuring the differential proton spectra in the energy range from 30 keV up to 30 MeV in the Earth radiation belts performed on the ''Kosmos-900'' satellite. According to the data obtained in the morning sector of magnetosphere a comparative analysis of differential proton spectra is carried out in the magnetically calm period of large duration and during magnetic agitation. In the range of Mc Ilvine parameter L approximately 3-5 differential proton spectra have maximum at the energy Ep approximately 100-300 keV. Maximum values Esub(max)(L) are higher in magnetically calm period than during magnetic agitation. This difference increases at L decrease, reaches the largest value on L=4 and decreases at further decrease of α. In the depth of plasmosphere (L approximately 3). Esub(max)(L) positions coincide in magnetically calm period and during magnetic agitation. A relation between Esub(max)(L) position in differential proton spectra and the average space distribution of cold plasma is traced

  17. Absorption of solar radiation by atmospheric water vapour

    International Nuclear Information System (INIS)

    Solar spectra from 0.7 to 2.5 μm were studied under low resolution for different solar zenith angles. The band integrated absorbance for water vapour bands at 0.8, 0.9, 1.1, 1.4 and 1.9 μm were measured and compared with those obtained by Howard et al. and other workers. It was found that although the agreement was satisfactory at lower water-vapour contents, there was significant deviation at high water-vapour content. (author)

  18. The slant path atmospheric refraction calibrator - An instrument to measure the microwave propagation delays induced by atmospheric water vapor

    Science.gov (United States)

    Walter, Steven J.; Bender, Peter L.

    1992-01-01

    The water vapor-induced propagation delay experienced by a radio signal traversing the atmosphere is characterized by the Slant Path Atmospheric Refraction Calibrator (SPARC), which measures the difference in the travel times between an optical and a microwave signal propagating along the same atmospheric path with an accuracy of 15 picosec or better. Attention is given to the theoretical and experimental issues involved in measuring the delay induced by water vapor; SPARC measurements conducted along a 13.35-km ground-based path are presented, illustrating the instrument's stability, precision, and accuracy.

  19. Measurement of IR atmospheric band dayglow by S-520-4 rocket

    International Nuclear Information System (INIS)

    The measurement of IR atmospheric band dayglow was made by rocket S-520-4 flown from Uchinoura at 1000 JST on Sept. 5, 1981. The instrument loaded on the rocket was the same type as the one loaded on EXOS-C satellite which will be launched in 1984 in order to observe the mesospheric ozone. This rocket experiment was performed for the purpose of testing the functions of this instrument in flight. The 1.27 μm filter radiometer consisted of three plane mirros, a camera lens, a chopper and a PbS detector array. The PbS array (4x5=20 elements) was operated at about -40C with a thermoelectric cooler. We obtained the following results from the rocket experiment: (i) this instrument worked well during the flight, (ii) the intensities of the solar radiation scattered by the sea and clouds were obtained at 1.27 μm, and (iii) the baffle designed to permit the daytime measurement of the atmospheric emission could attenuate the off-axis radiation as weak as possible. The altitude distribution of the daytime mesospheric ozone density derived from the downleg data was in agreement with the previous profile obtained in twilight condition. (author)

  20. Modelled Black Carbon Radiative Forcing and Atmospheric Lifetime in AeroCom Phase II Constrained by Aircraft Observations

    Energy Technology Data Exchange (ETDEWEB)

    Samset, B. H.; Myhre, G.; Herber, Andreas; Kondo, Yutaka; Li, Shao-Meng; Moteki, N.; Koike, Makoto; Oshima, N.; Schwarz, Joshua P.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Berntsen, T.; Bian, Huisheng; Chin, M.; Diehl, Thomas; Easter, Richard C.; Ghan, Steven J.; Iversen, T.; Kirkevag, A.; Lamarque, Jean-Francois; Lin, Guang; Liu, Xiaohong; Penner, Joyce E.; Schulz, M.; Seland, O.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, Kostas; Zhang, Kai

    2014-11-27

    Black carbon (BC) aerosols absorb solar radiation, and are generally held to exacerbate global warming through exerting a positive radiative forcing1. However, the total contribution of BC to the ongoing changes in global climate is presently under debate2-8. Both anthropogenic BC emissions and the resulting spatial and temporal distribution of BC concentration are highly uncertain2,9. In particular, long range transport and processes affecting BC atmospheric lifetime are poorly understood, leading to large estimated uncertainty in BC concentration at high altitudes and far from emission sources10. These uncertainties limit our ability to quantify both the historical, present and future anthropogenic climate impact of BC. Here we compare vertical profiles of BC concentration from four recent aircraft measurement campaigns with 13 state of the art aerosol models, and show that recent assessments may have overestimated present day BC radiative forcing. Further, an atmospheric lifetime of BC of less than 5 days is shown to be essential for reproducing observations in transport dominated remote regions. Adjusting model results to measurements in remote regions, and at high altitudes, leads to a 25% reduction in the multi-model median direct BC forcing from fossil fuel and biofuel burning over the industrial era.

  1. Molecular radiation - Its application in physical measurements and analyses

    Science.gov (United States)

    1969-01-01

    Specialists Conference held at Marshall Space Flight Center reviewed work in molecular radiation to evaluate research possibilities in this field. Topics included spectral-line studies in the labortory, application to practical heat transfer calculations of radiative transfer models, and use of measured radiation properties of gases.

  2. Review of measures to control radiation

    International Nuclear Information System (INIS)

    Methods used in Canada and the U.S.A. to overcome problems in the control of radiation, to prescribe standards and to ensure that compliance with the standards is achieved are reviewed. The relevant Acts and Regulations are outlined. Options which could be applied in Australia for effecting better control of radiation are suggested

  3. An unheated permeation device for calibrating atmospheric VOC measurements

    Directory of Open Access Journals (Sweden)

    J. Brito

    2011-10-01

    Full Text Available The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as on board aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, so that the instantaneous permeation rate can be ascribed to a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii a water bath as heat buffer, and (iii a vacuum-panel based insulation, in which features (ii and (iii minimize temperature drifts to ~30 mK h−1 per Kelvin temperature difference to the environment. The respective uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1%. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 μm dominates.

  4. An unheated permeation device for calibrating atmospheric VOC measurements

    Science.gov (United States)

    Brito, J.; Zahn, A.

    2011-10-01

    The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs) is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as on board aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, so that the instantaneous permeation rate can be ascribed to a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i) a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii) a water bath as heat buffer, and (iii) a vacuum-panel based insulation, in which features (ii) and (iii) minimize temperature drifts to ~30 mK h-1 per Kelvin temperature difference to the environment. The respective uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1%. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 μm) dominates.

  5. Exposure to the atmospheric ionizing radiation environment: a study on Italian civilian aviation flight personnel

    International Nuclear Information System (INIS)

    A study of the effects of high-LET, low-dose and low-dose-rate ionizing radiation and associated risk analysis is underway. This study involves analyzing the atmospheric ionizing radiation exposure (including high-energy neutrons) and associated effects for members of civilian aviation flight personnel, in an attempt to better understand low-dose long-term radiation effects on human subjects. The study population includes all Italian civilian airline flight personnel, both cockpit and cabin crew members, whose work history records and actual flights (route, aircraft type, and date for each individual flight for each person where possible) are available. The dose calculations are performed along specific flight legs, taking into account the actual flight profiles for all different routes and the variations with time of solar and geomagnetic parameters. Dose values for each flight are applied to the flight history of study participants in order to estimate the individual annual and lifetime occupational radiation dose. An update of the study of the physical atmospheric ionizing radiation exposure is given here, in terms of environmental modeling, flight routes, radiation dose evaluation along different flight paths, and exposure matrix construction. The exposure analysis is still in progress, and the first results are expected soon

  6. Comparisons of the MANTRA Balloon Campaign Measurements of Stratospheric Constituents with the Canadian Middle Atmospheric Model.

    Science.gov (United States)

    Melo, S. M.; McLandress, C.; Nowlan, C.; Farahani, E.; Shepherd, T.; Strong, K.; Wu, H.; McElroy, C. T.; McLinden, C.; Davies, J.; Goutail, F.; Fogal, P.; Blatherwick, R.

    2004-05-01

    MANTRA (Middle Atmosphere Nitrogen TRend Assessment) is a series of high-altitude balloon campaigns conducted in late summer over Saskatchewan to measure stratospheric trace gases from a float altitude of about 35 km. Previous flights have occurred in late August or early September of 1998, 2000 and 2002. By launching in late summer, dynamical variability is minimized and the changing chemical balance of the stratosphere can be studied, with an emphasis on the nitrogen partitioning. In this talk these MANTRA measurements are compared with the Canadian Middle Atmosphere Model (CMAM), a fully interactive chemistry climate model. Such comparison of model with measurements has many benefits: it helps to validate the model under conditions where the stratosphere is largely under photochemical and radiative control, but at the same time aids in the interpretation of the measurements. In particular, the model can help assess the representativeness of the measurements and the possible impact of dynamical variability. For example, we show that the model appears to simulate a realistic 5-day wave which has an impact on the chemical fields.

  7. Rotational Raman scattering of polarized light in the Earth atmosphere: a vector radiative transfer model using the radiative transfer perturbation theory approach

    International Nuclear Information System (INIS)

    A plane parallel vector radiative transfer model is presented to simulate the effect of rotational Raman scattering on radiance and polarization properties of sunlight reflected by the Earth atmosphere in the ultraviolet and visible part of the solar spectrum. The model employs the radiative transfer perturbation theory, which treats inelastic rotational Raman scattering as a perturbation to elastic Rayleigh scattering. The approach provides a perturbation series expansion for a simulated radiation quantity, where each term describes the effect of one additional order of Raman scattering. The model is worked out in detail to first order. Here, the adjoint formulation of radiative transfer reduces significantly the numerical effort of computational applications. Numerical simulations are presented for the ultraviolet part of the solar spectrum and the effect of Raman scattering on the Stokes parameters I,Q and U of the reflected sunlight is studied. Furthermore, the accuracy of both the single scattering approximation and the scalar radiative transfer approach is considered for the simulation of Ring structures. The use of these approximation techniques is investigated for the simulation of Ring structures in polarization sensitive GOME measurements

  8. Analysis of a Kalman filter based method for on-line estimation of atmospheric dispersion parameters using radiation monitoring data

    International Nuclear Information System (INIS)

    A Kalman filter method is discussed for on-line estimation of radioactive release and atmospheric dispersion from a time series of off-site radiation monitoring data. The method is based on a state space approach, where a stochastic system equation describes the dynamics of the plume model parameters, and the observables are linked to the state variables through a static measurement equation. The method is analysed for three simple state space models using experimental data obtained at a nuclear research reactor. Compared to direct measurements of the atmospheric dispersion, the Kalman filter estimates are found to agree well with the measured parameters, provided that the radiation measurements are spread out in the cross-wind direction. For less optimal detector placement it proves difficult to distinguish variations in the source term and plume height; yet the Kalman filter yields consistent parameter estimates with large associated uncertainties. Improved source term assessment results, when independent estimates of the plume height can be used. Perspectives for using the method in the context of nuclear emergency management are discussed, and possible extensions to the present modelling scheme are outlined, to account for realistic accident scenarios. (authors)

  9. Long term atmospheric radioxenon measurements and iodine-131 detections over Europe in 2011 and 2012

    International Nuclear Information System (INIS)

    The German Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz, BfS) continuously monitors the activity concentration of 133Xe in ground level air in Germany since 1976. Since 2004, Xenon is measured at Schauinsland in samples with 24 hours sampling time with the automated system SPALAX as part of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Furthermore the BfS operates two high air volume samplers, one in Freiburg and one at the monitoring station Schauinsland. The surveillance of radioactive traces in the atmosphere is part of the German monitoring program of the Integrated Measurement and Information System (IMIS). The available data set allow the study of trends over long time periods and therefore the influence of different sources. Possible sources and their contribution could be investigated by the methods of Atmospheric Transport Modelling (ATM). Beside radioactive xenon isotopes also the medical isotope 131I is released in traces into the atmosphere and the detection at single trace analysis stations is not exceptional. However, in autumn 2011 and spring 2012 traces of this radioisotope were detected over longer periods over Europe. These events clearly showed the importance of a fast, transboundary and comprehensive data exchange between institutions to identify and localize the source.

  10. On the marine atmospheric boundary layer characteristics over Bay of Bengal and Arabian Sea during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB)

    Indian Academy of Sciences (India)

    Denny P Alappattu; D Bala Subrahamanyam; P K Kunhikrishnan; K M Somayaji; G S Bhat; R Venkatesan; C B S Dutt; A Bagavath Singh; V K Soni; A S Tripathi

    2008-07-01

    Detailed measurements were carried out in the Marine Atmospheric Boundary Layer (MABL) during the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB) which covered both Arabian Sea and Bay of Bengal during March to May 2006. In this paper, we present the meteorological observations made during this campaign. The latitudinal variation of the surface layer turbulent fluxes is also described in detail.

  11. A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy

    International Nuclear Information System (INIS)

    We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0 mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5 × 1017 cm−3 and peak N atom densities of 9.9 × 1017 cm−3 are observed within the first ∼1.0 mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0 nm band of the vacuum ultraviolet spectrum

  12. Measurement of atmospheric neutrino oscillations and matter effects with PINGU

    International Nuclear Information System (INIS)

    With IceCube's low-energy extension DeepCore the first significant effects of atmospheric neutrino oscillations have been observed. The planned ''Precision Icecube Next Generation Upgrade'' (PINGU) inside DeepCore will lower the energy threshold to a few GeV, where matter effects of neutrino oscillations have to be taken into account. The Mikheyev-Smirnov-Wolfenstein (MSW) effect modifies the mixing between flavor and mass eigenstates of the neutrinos, resulting in stronger oscillations. Furthermore, neutrinos when passing through the Earth core experience parametric enhancement due to multiple discontinuities in the electron density. In this talk the effects of matter oscillations and the capabilities to measure these effects with PINGU are investigated.

  13. Measurement of atmospheric contamination by double mandarin (1961)

    International Nuclear Information System (INIS)

    - To check the radioactivity of the air in laboratories where plutonium is handled, an apparatus known as 'Double Mandarin' was devised. This instrument distinguishes plutonium dusts from those which carry natural active deposits, by making use of the granulometric difference between these two types of particle. The separation is based on the use of selective filters placed in series. An electronic unit enables the activities of the dusts collected on the two filters to be measured continuously and immediately. This apparatus is simple in design and should provide a means of checking atmospheric contamination. Its performance is particularly satisfactory in the case of laboratories where the air is filtered. Under these conditions it is possible to detect 70 times the CMA after one minute and 7 times this concentration in 10 minutes. (authors)

  14. Measurement of Radiation Pressure in an Ambient Environment

    Science.gov (United States)

    Ma, Dakang; Garrett, Joseph; Munday, Jeremy

    2015-03-01

    Light has momentum and thus exerts ``radiation pressure'' when it is reflected or absorbed due to the conservation of momentum. Micromechanical transducers and oscillators are suitable for measurement and utilization of radiation pressure due to their high sensitivities. However, other light-induced mechanical deformations such as photothermal effects often obscure accurate measurements of radiation pressure in these systems. In this work, we investigate the radiation pressure and photothermal force on an uncoated silicon nitride microcantilever under illumination by a 660 nm laser in an ambient environment. To magnify the mechanical effects, the cantilever is driven optically from dc across its resonance frequency, and the amplitude and phase of its oscillation are acquired by an optical beam deflection method and a lockin amplifier. We show that radiation pressure and photothermal effects can be distinguished through the cantilever's frequency response. Furthermore, in a radiation pressure dominant regime, our measurement of the radiation force agrees quantitatively with the theoretical calculation.

  15. Effects of hydrodynamics and thermal radiation in the atmosphere after comet impacts

    Science.gov (United States)

    Nemchinov, I. V.; Popova, M. P.; Shubadeeva, L. P.; Shuvalov, V. V.; Svetsov, V. V.

    1993-01-01

    Radiation phenomena in the atmosphere after impacts of cosmic bodies have special features in comparison with the surface nuclear explosions. First, initial concentration of energy after the impact is lower, and second, a wake after the passage of the meteoroid through the atmosphere has a dramatic effect on the atmospheric flow and radiation transfer. Consequently, scaling laws can not be employed for prediction of the flow in the atmosphere and the light flux on the Earth's surface. If a density of high-velocity impactor is low relative to the ground, as in a case of a comet impact on rocks, a major part of the kinetic energy is converted to internal energy of dense hot vapors. But radiation effects can be essential even for fairly low velocities of the impactor. To clarify this issue we have undertaken calculations of 100-Mt explosions at the Earth's surface caused by small comets with velocities from 10 to 70 km/sec. That is, the initial concentration of energy has been varied. The calculations have shown that for velocities of the comet greater or about 20 km/sec a portion of energy emitted from the fireball exceeds 20% of the total energy of the explosion and this quantity does not change very much with the velocity. Other aspects of this investigation are discussed.

  16. Atmospheric extinction in solar tower plants: absorption and broadband correction for MOR measurements

    Directory of Open Access Journals (Sweden)

    N. Hanrieder

    2015-08-01

    Full Text Available Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrated solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in ray-tracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested, and more than 19 months of measurements were collected and compared at the Plataforma Solar de Almería. Both instruments are primarily used to determine the meteorological optical range (MOR. The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for concentrated solar power (CSP, a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the time-dependent solar spectrum which is reflected by the collector. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the absorption and broadband correction (ABC procedure

  17. Atmospheric extinction in solar tower plants: absorption and broadband correction for MOR measurements

    Science.gov (United States)

    Hanrieder, N.; Wilbert, S.; Pitz-Paal, R.; Emde, C.; Gasteiger, J.; Mayer, B.; Polo, J.

    2015-08-01

    Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrated solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in ray-tracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested, and more than 19 months of measurements were collected and compared at the Plataforma Solar de Almería. Both instruments are primarily used to determine the meteorological optical range (MOR). The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED) light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for concentrated solar power (CSP), a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the time-dependent solar spectrum which is reflected by the collector. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the absorption and broadband correction (ABC) procedure, additional

  18. Mobile non ionizing radiation measurement system

    International Nuclear Information System (INIS)

    Most regulations ask for levels of EM radiation in an area surrounding telecommunications installations. These might interest close neighbors but does not help in the risk perception of population at large. That is what makes interesting measurements on a geographic basis, that is, covering an area with certain minimum resolution. Until now this has been done statically, that is on fixed positions such as city road intersections. That equals one measurement each city block or a spatial resolution of 100 points/km2. On our experience, with an acquisition time of 6 minutes/point we do from 6 to 10 points/h or 10 to 17 h/km2. On a dynamic or mobile system we acquire simultaneously the signal from a GPS and synchronize it with the NIR measuring equipment in a portable computer. This way each measurement can be associated with a position and time. Now speed of acquisition will depend on sampling time at the meter, selectable from 0.4 to 2 sec, and displacement velocity. During acquisition we simply get a table of values. To display them in convenient form for the public at large, we utilized commercial mapping software and satellite images. We found that 4 measurements for each city block is the maximum acceptable for a reasonably meaningful display of results. A scale of colors will indicate value, where green will indicate low ones, yellow for intermediates and red for values above permitted levels. Nevertheless, since actual values are mostly well below limits, we use a scale of greens to remark small differences as we move. The system was tested on selected areas of Cordoba, population 1,3 million. With an average ''cruising speed'' of 36 km at the transport vehicle, acceptable for normal traffic conditions, we achieved 440 points/m2 in less than 20 min. Since common GPS receivers have systematic static errors on the order of +/- 6 meters plus a drift with time, our mapping must be corrected after acquisition, typically adjusted to the city streets where we

  19. Measuring atmospheric naphthalene with laser-induced fluorescence

    Directory of Open Access Journals (Sweden)

    M. Martinez

    2004-01-01

    Full Text Available A new method for measuring gas-phase naphthalene in the atmosphere is based on laser-induced fluorescence at low pressure. The fluorescence spectrum of naphthalene near 308 nm was identified. Naphthalene fluorescence quenching by N2, O2 and H2O was investigated in the laboratory. No significant quenching was found for H2O with mixing ratio up to 2.5%. The quenching rate of naphthalene fluorescence is (1.98±0.18×10−11 cm3 molecule−1 s−1 for N2, and (2.48±0.08×10−10 cm3 molecule−1 s−1 for O2 at 297 K. Instrument calibrations were performed with a range of naphthalene mixing ratios between 5 and 80 parts per billion by volume (ppbv, 10−9. In the current instrument configuration, the detection limit is estimated to be about 20 parts per trillion by volume (pptv, 10−12 with 2σ confidence and a 1-min integration time. Measurement of atmospheric naphthalene in three cities, Nashville, TN, Houston, TX, and New York City, NY, are presented. Good correlation between naphthalene and major anthropogenic pollutants is found.

  20. Using a simple apparatus to measure direct and diffuse photosynthetically active radiation at remote locations.

    Directory of Open Access Journals (Sweden)

    Michael J Cruse

    Full Text Available Plant canopy interception of photosynthetically active radiation (PAR drives carbon dioxide (CO2, water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the

  1. Effect of ambient pressure and radiation reabsorption of atmosphere on the flame spreading over thermally thin combustibles in microgravity

    Institute of Scientific and Technical Information of China (English)

    DU; Wenfeng; (杜文峰); HU; Wenrui; (胡文瑞)

    2003-01-01

    For the flame spread over thermally thin combustibles in an atmosphere, if the atmosphere cannot emit and absorb the thermal radiation (e.g. for atmosphere of O2-N2), the conductive heat transfer from the flame to the fuel surface dominates the flame spread at lower ambient atmosphere. As the ambient pressure increases, the flame spread rate increases, and the radiant heat transfer from the flame to the fuel surface gradually becomes the dominant driving force for the flame spread. In contrast, if the atmosphere is able to emit and absorb the thermal radiation (e.g. for atmosphere of O2-CO2), at lower pressure, the heat transfer from flame to the fuel surface is enhanced by the radiation reabsorption of the atmosphere at the leading edge of the flame, and both conduction and thermal radiation play important roles in the mechanism of flame spread. With the increase in ambient pressure, the oxygen diffuses more quickly from ambient atmosphere into the flame, the chemical reaction in the flame is enhanced, and the flame spread rate increases. When the ambient pressure is greater than a critical value, the thermal radiation from the flame to the solid surface is hampered by the radiation reabsorption of ambient atmosphere with the further increase in ambient pressure. As a result, with the increase in ambient pressure, the flame spread rate decreases and the heat conduction gradually dominates the flame spread over the fuel surface.

  2. The efficiency of propagation of radiation from different lasers through the turbulent Earth's atmosphere

    International Nuclear Information System (INIS)

    A simplified model of the propagation of intense laser beams in the turbulent Earth's atmosphere along horizontal and oblique paths is improved. The model takes into account the basic mechanisms of interaction of laser radiation with the Earth's atmosphere (molecular absorption, aerosol extinction, turbulence-induced beam spread and wander). The application of this model demonstrates a general approach to determining the optimal radiation wavelengths for attaining the maximum intensity of focused laser radiation at a stationary object depending on the path length, angle of the path inclination, weather conditions, and diameter of the laser output beam. A simple physical interpretation of the dependences obtained is presented. The efficiencies of propagation of various high-power laser beams through the turbulent Earth's atmosphere are compared. Specific features of the energy transfer from various lasers to moving objects are analysed. It is shown that, when weather conditions change over a wide range, it is expedient to use radiation from a cw chemical DF laser. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  3. SPARTA - Solver for Polarized Atmospheric Radiative Transfer Applications: Introduction and application to Saharan dust fields

    Science.gov (United States)

    Barlakas, Vasileios; Macke, Andreas; Wendisch, Manfred

    2016-07-01

    Non-spherical particles in the atmosphere absorb and scatter solar radiation. They change the polarization state of solar radiation depending on their shape, size, chemical composition and orientation. To quantify polarization effects, a new three-dimensional (3D) vector radiative transfer model, SPARTA (Solver for Polarized Atmospheric Radiative Transfer Applications) is introduced and validated against benchmark results. SPARTA employs the statistical forward Monte Carlo technique for efficient column-response pixel-based radiance calculations including polarization for 3D inhomogeneous cloudless and cloudy atmospheres. A sensitivity study has been carried out and exemplarily results are presented for two lidar-based mineral dust fields. The scattering and absorption properties of the dust particles have been computed for spheroids and irregular shaped particles. Polarized radiance fields in two-dimensional (2D) and one-dimensional (1D) inhomogeneous Saharan dust fields have been calculated at 532 nm wavelength. The domain-averaged results of the normalized reflected radiance are almost identical for the 1D and 2D modes. In the areas with large spatial gradient in optical thickness with expected significant horizontal photon transport, the radiance fields of the 2D mode differ by about ±12% for the first Stokes component (radiance, I) and ±8% for the second Stokes component (linear polarization, Q) from the fields of the 1D mode.

  4. A proposed reference set of scenarios for radiatively active atmospheric constituents

    International Nuclear Information System (INIS)

    Over the last few decades, advances in observation techniques coupled with an improved understanding of atmospheric chemical and physical processes have demonstrated that concentrations are changing for a number of radiatively and chemically active trace gases. Theoretical model calculations suggest that increasing concentrations of radiatively important atmospheric trace gases such as methane, nitrous oxide and several chlorofluorocarbons may add to the climatic warming expected from increasing CO2 concentrations alone by approximately 50%. Because of complex nonlinear interactions, numerical models of the chemical and climate systems are required to predict the CICECC. Except for studies of the effect of increasing CO2 concentrations on climate, most model studies of potential CICECC have focused on the chemical effects and have used relatively simple one-dimensional radiative-convective-kinetics models. As a first step in improving coordination, the goal of the present study is to develop a set of scenarios for past and future concentrations of radiatively active atmospheric constituents. These scenarios are intended to promote discussion leading to generally accepted sets of scenarios that can serve not as a forecast but as a reference for all research groups studying the continental and global-scale chemical interactions and climatic effects of these concentration changes. No attempt is made here to give detailed budgets for each of the gases discussed. Instead, existing budget analyses and correspondingly recognized uncertainties in the budgets are cited and discussed in the scenarios developed here

  5. Effect Analysis on the Radiation Dose Rate of Nagasaki Atomic Bomb Survivors by Atmospheric Condition

    International Nuclear Information System (INIS)

    The Dosimetry System 2002 (DS02) had been established to evaluate the radiation doses for the atomic bomb survivors in Hiroshima and Nagasaki. The radiation effects of neutrons and gamma-rays emitted from the atomic bombs detonated at both cities were analyzed, and two types of radiation transport codes (i.e., MCNP4C and DORT) were employed in their studies. It was specifically investigated for contribution of each type of radiations to total dose. However, it is insufficient to examine the effects by various environmental factors such as weather conditions, because their calculations were only performed under certain condition at the times of the bombings. In addition, the scope of them does not include acute radiation injury of the atomic bomb survivors in spite of important information for investigating hazard of unexpected radiation accident. Therefore, this study analyzed the contribution of primary and secondary effects (i.e., skyshine and groundshine) of neutrons emitted from the Nagasaki atomic bomb. These analyses were performed through a series of radiation transport calculations by using MCNPX 2.6.0 code with variations of atmospheric density. The acute radiation injury by prompt neutrons was also evaluated as a function of distance from the hypocenter, where hypocenter is the point on the ground directly beneath the epicenter which is the burst point of the bomb in air

  6. Radiation detection and measurement student solutions manual

    CERN Document Server

    Wehe, David K

    2012-01-01

    This is the resource that engineers turn to in the study of radiation detection. The fourth edition takes into account the technical developments that continue to enhance the instruments and techniques available for the detection and spectroscopy of ionizing radiation. New coverage is presented on ROC curves, micropattern gas detectors, new sensors for scintillation light, and the excess noise factor. Revised discussions are also included on TLDs and cryogenic spectrometers, radiation backgrounds, and the VME standard. Engineers will gain a strong understanding of the field with this updated book.

  7. Optical radiation measurements II; Proceedings of the Meeting, Orlando, FL, Mar. 27, 28, 1989

    Science.gov (United States)

    Palmer, James M. (Editor)

    1989-01-01

    The present conference discusses topics in the characterization of imaging radiometers, laboratory instrumentation, field and spacecraft instrumentation, and quantum and thermal standard detectors. Attention is given to UV radiometric imaging, dual-color radiometer imagery, a novel diode-array radiometer, a novel reference spectrophotometer, radiance calibration of spherical integrators, instrumentation for measurement of spectral goniometric reflectance, and a real-time IR background discrimination radiometer. Also discussed are a multichannel radiometer for atmosphere optical property measurements, the UV spectroradiometric output of a turbojet, characterizations of the Earth Radiation Budget Experiment scanning radiometers, total-radiation thermometry, future directions in Si photodiode self-calibration, and radiometric quality Ge photodiodes.

  8. Comparison of free radicals formation induced by cold atmospheric plasma, ultrasound, and ionizing radiation.

    Science.gov (United States)

    Rehman, Mati Ur; Jawaid, Paras; Uchiyama, Hidefumi; Kondo, Takashi

    2016-09-01

    Plasma medicine is increasingly recognized interdisciplinary field combining engineering, physics, biochemistry and life sciences. Plasma is classified into two categories based on the temperature applied, namely "thermal" and "non-thermal" (i.e., cold atmospheric plasma). Non-thermal or cold atmospheric plasma (CAP) is produced by applying high voltage electric field at low pressures and power. The chemical effects of cold atmospheric plasma in aqueous solution are attributed to high voltage discharge and gas flow, which is transported rapidly on the liquid surface. The argon-cold atmospheric plasma (Ar-CAP) induces efficient reactive oxygen species (ROS) in aqueous solutions without thermal decomposition. Their formation has been confirmed by electron paramagnetic resonance (EPR) spin trapping, which is reviewed here. The similarities and differences between the plasma chemistry, sonochemistry, and radiation chemistry are explained. Further, the evidence for free radical formation in the liquid phase and their role in the biological effects induced by cold atmospheric plasma, ultrasound and ionizing radiation are discussed. PMID:27085689

  9. Consistent sets of atmospheric lifetimes and radiative forcings on climate for CFC replacements: HCFCs and HFCs

    Science.gov (United States)

    Naik, Vaishali; Jain, Atul K.; Patten, Kenneth O.; Wuebbles, Donald J.

    2000-03-01

    Recognition of deleterious effects of chlorine and bromine on ozone and climate over the last several decades has resulted in international accords to halt the production of chlorine-containing chlorofluorocarbons (CFCs) and bromine-containing halons. It is well recognized, however, that these chemicals have had important uses to society, particularly as refrigerants, as solvents, as plastic blowing agents, as fire retardants and as aerosol propellants. This has led to an extensive search for substitute chemicals with appropriate properties to be used in place of the CFCs and halons. The purpose of this study is to evaluate in a consistent manner the atmospheric lifetime and radiative forcing on climate for a number of replacement compounds. The unique aspect of this study is its attempt to resolve inconsistencies in previous evaluations of atmospheric lifetimes and radiative forcings for these compounds by adopting a uniform approach. Using the latest version of our two-dimensional chemical-radiative-transport model of the global atmosphere, we have determined the atmospheric lifetimes of 28 hydrohalocarbons (HCFCs and HFCs). Through the comparison of the model-calculated lifetimes with lifetimes derived using a simple scaling method, our study adds to earlier findings that consideration of stratospheric losses is important in determining the lifetimes of gases. Discrepancies were found in the reported lifetimes of several replacement compounds reported in the international assessment of stratospheric ozone published by the World Meteorological Organization [Granier et al., 1999] and have been resolved. We have also derived the adjusted and instantaneous radiative forcings for CFC-11 and 20 other halocarbons using our radiative transfer model. The sensitivity of radiative forcings to the vertical distribution of these gases is investigated in this study and is shown to be significant. The difference in the global radiative forcing arising from the assumption of a

  10. Measurement of viscosity of gaseous mixtures at atmospheric pressure

    Science.gov (United States)

    Singh, J. J.; Mall, G. H.; Chegini, H.

    1986-01-01

    Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model.

  11. Calculating isotopic fractionation from atmospheric measurements at various scales

    International Nuclear Information System (INIS)

    In this paper we describe some new approaches for calculating isotopic discrimination from atmospheric measurements of CO2 and 13C. We introduce a framework that is more flexible than the traditional 'Keeling plot' two end-member mixing model, because it allows for the explicit specification of the background values of both CO2 and 13C. This approach is necessary for evaluating time series for which one can be certain that the Keeling plot requirement of stable background is violated. We also discuss a robust method for curve fitting and for estimating uncertainty of the fitting parameters. In addition to accounting for the uncertainty associated with measurements, we also account for the uncertainty associated with the appropriateness of the analytical model to the data. Our analysis suggests that uncertainty in calculated source signatures is more strongly related to the appropriateness of the model to the data than to the analytical precision of CO2 and 13C measurements. Relative to our approach, other approaches tend to underestimate the uncertainty in the fitted parameters. There can be substantial uncertainty in slopes and intercepts (two per mil or more) even if R2 is greater than 0.98. In addition, we note that fitting methods not accounting for uncertainty in both x and y result in systematic biases in the fitted parameters. Finally, we discuss the interpretation of the apparent isotopic source signature when this is a composite of several sources

  12. McSCIA: application of the Equivalence Theorem in a Monte Carlo radiative transfer model for spherical shell atmospheres

    Directory of Open Access Journals (Sweden)

    F. Spada

    2006-02-01

    Full Text Available A new multiple-scattering Monte Carlo 3-D radiative transfer model named McSCIA (Monte Carlo for SCIAmachy is presented. The backward technique is used to efficiently simulate narrow field of view instruments. The McSCIA algorithm has been formulated as a function of the Earth's radius, and can thus perform simulations for both plane-parallel and spherical atmospheres. The latter geometry is essential for the interpretation of limb satellite measurements, as performed by SCIAMACHY on board of ESA's Envisat. The model can simulate UV-vis-NIR radiation.

    First the ray-tracing algorithm is presented in detail, and then successfully validated against literature references, both in plane-parallel and in spherical geometry. A simple 1-D model is used to explain two different ways of treating absorption. One method uses the single scattering albedo while the other uses the equivalence theorem. The equivalence theorem is based on a separation of absorption and scattering. It is shown that both methods give, in a statistical way, identical results for a wide variety of scenarios. Both absorption methods are included in McSCIA, and it is shown that also for a 3-D case both formulations give identical results. McSCIA limb profiles for atmospheres with and without absorption compare well with the one of the state of the art Monte Carlo radiative transfer model MCC++.

    A simplification of the photon statistics may lead to very fast calculations of absorption features in the atmosphere. However, these simplifications potentially introduce biases in the results. McSCIA does not use simplifications and is therefore a relatively slow implementation of the equivalence theorem. For the first time, however, the validity of the equivalence theorem is demonstrated in a spherical 3-D radiative transfer model.

  13. Atmospheres and radiating surfaces of neutron stars with strong magnetic fields

    CERN Document Server

    Potekhin, A Y; Chabrier, G

    2016-01-01

    We review the current status of the theory of thermal emission from the surface layers of neutron stars with strong magnetic fields $B\\sim 10^{10}-10^{15}$ G, including formation of the spectrum in a partially ionized atmosphere and at a condensed surface. In particular, we describe recent progress in modeling partially ionized atmospheres of central compact objects in supernova remnants, which may have moderately strong fields $B\\sim 10^{10}-10^{11}$ G. Special attention is given to polarization of thermal radiation emitted by a neutron star surface. Finally, we briefly describe applications of the theory to observations of thermally emitting isolated neutron stars.

  14. Calibration of personnel radiation measurement instruments

    International Nuclear Information System (INIS)

    Thermoluminescent analyzer (TLA) calibration procedures were used to estimate personnel radiation exposure levels at the Idaho National Engineering Laboratory (INEL). A statistical analysis is presented herein based on data collected over a six-month period in 1979 on four TLA's located in the Department of Energy Radiological and Environmental Sciences Laboratory at the INEL. Both gamma and beta radiation models are developed. Observed TLA readings of thermoluminescent dosimeters are correlated with known radiation levels. This correlation is then used to predict unknown radiation doses from future analyzer readings of personnel thermoluminescent dosimeters. The statistical techniques applied in this analysis include weighted linear regression, estimation of systematic and random error variances, prediction interval estimation using Scheffe's theory of calibration, the estimation of the ratio of the means of two normal bivariate distributed random variables and their corresponding confidence limits according to Kendall and Stuart, tests of normality, experimental design, a comparison between instruments, and quality control

  15. About Solar Radiation Intensity Measurements and Data Processing

    Directory of Open Access Journals (Sweden)

    MICH-VANCEA Claudiu

    2012-10-01

    Full Text Available Measuring the intensity of solar radiation is one of the directions of investigation necessary for the implementation of photovoltaic systems in a particular geographical area. This can be done by using specific measuring equipment (pyranometer sensors based onthermal or photovoltaic principle. In this paper it is presented a method for measuring solar radiation (which has two main components - direct radiation and diffuse radiation with sensors based on photovoltaic principle. Such data are processed for positioning solarpanels, in order their efficiency to be maximized.

  16. Measurements of Physical and Gas Exchanges between the Atmosphere and Surface at the Tiksi Hydrometeorological Observatory

    Science.gov (United States)

    Uttal, T.; Grachev, A. A.; Makshtas, A. P.; Repina, I.; Persson, O. P.; Laurila, T. J.; Crepinsek, S.

    2013-12-01

    In recent years a number of Arctic stations have installed micro-meteorological towers in recognition of the need to explicitly quantify the detailed exchanges between the surface and the atmosphere. One of the newer installations is a 20 meter tower in Tiksi, Russia that is located at 71.58N, 128.92E in the Russian Far East. The Tiksi tower is equipped with temperature, humidity and wind sensors at several levels (allowing the calculation of turbulent heat fluxes and fine scale characterization of the near-surface boundary layer) and H2O/CO2 sensors, It is located in near proximity to measurements of incoming and outgoing solar radiation (allowing energy balance calculations), and CH4 sensors, surface O3 measurements (allowing detection of ozone depletion events), and ancillary measurements of snow depth and permafrost active layer temperature profiles. An integrated analysis will look at the variability of these physical and chemical exchanges and variations over one annual cycle with an emphasis on detecting connections and linkages. This network of measurements supports the International Arctic Systems for Observing the Atmosphere (www.iasoa.org) and Global Cryosphere Watch (http://globalcryospherewatch.org/)

  17. Aerosol hygroscopicity and its impact on atmospheric visibility and radiative forcing in Guangzhou during the 2006 PRIDE-PRD campaign

    Science.gov (United States)

    Liu, Xingang; Zhang, Yuanhang; Cheng, Yafang; Hu, Min; Han, Tingting

    2012-12-01

    The objective of this study is to quantify the relation of aerosol chemical compositions and optical properties, and to assess the impact of relative humidity (RH) on atmospheric visibility and aerosol direct radiative forcing (ADRF). Mass concentration and size distribution of aerosol chemical compositions as well as aerosol optical properties were concurrently measured at Guangzhou urban site during the PRD (Pearl River Delta) campaign from 1 to 31 July, 2006. Gaseous pollutant NO2 and meteorological parameter were simultaneously monitored. Compared with its dry condition, atmospheric ambient extinction coefficient σext(RH) averagely increased about 51% and atmospheric visibility deceased about 35%, among which RH played an important role on the optical properties of water soluble inorganic salts. (NH4)2SO4 is the most important component responsible for visibility degradation at Guangzhou. In addition, the asymmetry factor g increased from 0.64 to 0.74 with the up-scatter fraction β decreasing from 0.24 to 0.19 when RH increasing from 40% to 90%. At 80% RH, the ADRF increased about 280% compared to that at dry condition and it averagely increased about 100% during the campaign under ambient conditions. It can be inferred that aerosol water content is a key factor and could not be ignored in assessing the role of aerosols in visibility impairment and radiative forcing, especially in the regions with high RH.

  18. Climate variability and relationships between top-of-atmosphere radiation and temperatures on Earth

    Science.gov (United States)

    Trenberth, Kevin E.; Zhang, Yongxin; Fasullo, John T.; Taguchi, Shoichi

    2015-05-01

    The monthly global and regional variability in Earth's radiation balance is examined using correlations and regressions between atmospheric temperatures and water vapor with top-of-atmosphere outgoing longwave (OLR), absorbed shortwave (ASR), and net radiation (RT = ASR - OLR). Anomalous global mean monthly variability in the net radiation is surprisingly large, often more than ±1 W m-2, and arises mainly from clouds and transient weather systems. Relationships are strongest and positive between OLR and temperatures, especially over land for tropospheric temperatures, except in the deep tropics where high sea surface temperatures are associated with deep convection, high cold cloud tops and thus less OLR but also less ASR. Tropospheric vertically averaged temperatures (surface = 150 hPa) are thus negatively correlated globally with net radiation (-0.57), implying 2.18 ± 0.10 W m-2 extra net radiation to space for 1°C increase in temperature. Water vapor is positively correlated with tropospheric temperatures and thus also negatively correlated with net radiation; however, when the temperature dependency of water vapor is statistically removed, a significant positive feedback between water vapor and net radiation is revealed globally with 0.87 W m-2 less OLR to space per millimeter of total column water vapor. The regression coefficient between global RT and tropospheric temperature becomes -2.98 W m-2 K-1 if water vapor effects are removed, slightly less than expected from blackbody radiation (-3.2 W m-2 K-1), suggesting a positive feedback from clouds and other processes. Robust regional structures provide additional physical insights. The observational record is too short, weather noise too great, and forcing too small to make reliable estimates of climate sensitivity.

  19. Comparative Experimental Investigation of Titan's Atmospheric Chemistry Driven by Solar EUV Radiation and Energetic Electron Precipitation

    Science.gov (United States)

    Imanaka, Hiroshi; Lavvas, P.; Yelle, R. V.; Smith, M. A.

    2010-10-01

    The observations by the Cassini Ion Neutral Mass Spectrometer (INMS) and the Cassini Plasma Spectrometer (CAPS) clearly demonstrate the importance of complex organic chemistry in the upper atmosphere of Titan; a complex coupling of neutral and ion chemistry for organic aerosol generation induced by EUV photons and Saturn's magnetospheric charged particles. To understand the dominant energy source for aerosol formation and its formation chemistry, we comparatively investigate the chemical mechanism in N2/CH4 gas mixtures resulting from EUV-VUV synchrotron radiation (50-150 nm) and tunable mono-energetic electron beam irradiation (5 eV - 2000 eV). These excitation energy sources cover the dominant energy source available in Titan's upper atmosphere. Our previous study of the EUV-VUV photolysis of N2/CH4 gas mixtures revealed the unique role of nitrogen photoionization in the catalytic formation of complex hydrocarbons and in the major nitrogen fixation process in Titan's upper atmosphere (Imanaka and Smith, 2007, 2009, 2010). However, relative roles of ion-molecule reactions and radical/neutral reactions in such complex chemistry remain to be determined. We characterized the electron energy distribution by conducting the Langmuir probe measurements. Degradation of the primary photoelectron from N2 photoionization at 20.6 eV photons is clearly observed, and the electron density rapidly decreases down to 109-10 cm-3, which suggests the complex coupling of ion-molecular reactions and dissociative ion-electron recombination reactions for the observed development of complex organic molecules. The electron beam irradiation experiments at energy larger than 200 eV shows distinct gaseous product distribution with nitrogenated gaseous species from those with EUV irradiation products. The generation of secondary electrons and multiple inelastic collisions of fast electrons might increases the nitrogen fixation efficiency. The much less stringent spin selection rules could

  20. Open-Path FTIR Spectral Radiation Intensity Of Hot Combustion Gases – Measurement And Interpretation

    Directory of Open Access Journals (Sweden)

    Cięszczyk Sławomir

    2015-06-01

    Full Text Available Spectral remote sensing is a very popular method in atmospheric monitoring. The paper presents an approach that involves mid-infrared spectral measurements of combustion processes. The dominant feature in this spectral range is CO2 radiation, which is used to determine the maximum temperature of nonluminous flames. Efforts are also made to determine the temperature profile of hot CO2, but they are limited to the laboratory conditions. The paper presents an analysis of the radiation spectrum of a non-uniform-temperature gas environment using a radiative transfer equation. Particularly important are the presented experimental measurements of various stages of the combustion process. They allow for a qualitative description of the physical phenomena involved in the process and therefore permit diagnostics. The next step is determination of a non-uniform-temperature profile based on the spectral radiation intensity with the 8 m optical path length.