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Sample records for airs infrared sounder

  1. AIRS - the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Lambrigsten, Bjorn H.; Fetzer, Eric; Fishbein, Evan; Lee, Sung-Yung; Paganao, Thomas

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched in 2002, along with two companion microwave sounders. This AIRS sounding suite is the most advanced atmospheric sounding system to date, with measurement accuracies far surpassing those of current weather satellites. From its sun synchronous polar orbit, the AIRS system provides more than 90% of the globe every 24 hours. Much of the post-launch period has been devoted to optimizing the 'retrieval' system used to derive atmospheric and other parameters from the observations and to validate those parameters. The geophysical parameters have been produced since the beginning of 2003 - the first data were released to the public in mid-2003, and future improved versions will be released periodically. The ongoing calibration/validation effort has confirmed that the system is very accurate and stable. There are a number of applications for the AIRS products, ranging from numerical weather prediction - where positive impact on forecast accuracy has already been demonstrated, to atmospheric research - where the AIRS water vapor products near the surface and in the mid and upper troposphere as well as in the stratosphere promise to make it possible to characterize and model phenomena that are key for short-term atmospheric processes, from weather patterns to long-term processes, such as interannual variability and climate change.

  2. Atmospheric Infrared Sounder (AIRS) Project Status

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2006-01-01

    This viewgraph presentation reviews the status of the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU). These instruments are on board the EOS Aqua Spacecraft that was launched May 4, 2002. The instruments are working normally. The objectives of the mission were to improve weather forecasting, assist in climate studies, and provide information as to the composition of Earth's atmosphere. The Aqua spacecraft is operating normally, the the primary life-limiting resource is fuel for maneuvers. The presentation also contains charts indicating who are using the data. There is information on the type of data available, and the propsal process. Also there is a few views of some of the planned instruments that were made possible in part due to the success of AIRS.

  3. Application of Atmospheric Infrared Sounder (AIRS) Data to Climate Research

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, David; Gaiser, Steve; Chahine, Moustafa T.

    2004-01-01

    The application of hyper spectral radiometric data to climate research requires very high absolute radiometric accuracy and stability. We use cloud-free tropical ocean data from the Atmospheric InfraRed Sounder (AIR) Calibration Data Subset (ADCS) to show that the radiometric precision and stability required climate applications has been achieved. The sea surface skin temperatures derived from the AIRS 2616cm-1 super window channel are stable relative to the RTG.SST at the better than 8 mK/year level, and the spectral calibration is stable at the 1 ppm/year level. The excellent stability and accuracy are the result of the implementation of AIRS as a grating array spectrometer, which is cooled and stabilized within 10 mK at 155 K. Analysis of daily measurements of the temperature gradient between the surface and 7 km altitude show that the AIRS Calibration Data Subset has applications which extend its original intent for calibration support to climate research. The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua satellite was launched into polar orbit in May 2002. AIRS covers the spectral region from 640 to 2700 cm-1 with 2378 independent channels and represents the first of a new generation of hyper spectral resolution sounders in support of global sounding data for weather forecasting and climate research.

  4. The Atmospheric Infrared Sounder (AIRS) on the Earth Observing System

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Pagano, Thomas S.; Strow, Larrabee

    2001-01-01

    AIRS, the Atmospheric Infrared Sounder on the EOS-Aqua, produces global high precision spectra from 3.7 - 15.4 micron with spectral resolving power mu/delta mu = 1200 twice each day from 708 km orbital altitude. AIRS is the first hyperspectral infrared spectrometer designed to support NOAA/NCEP's operational requirements for medium range weather forecasting during its nominal 7 year lifetime. AIRS, together with the AMSU and HSB microwave radiometers, will achieve global retrieval accuracy of better then 1K rms in the lower troposphere under clear and partly cloudy condition. Based on the excellent radiometric and spectral performance demonstrated during the pre-launch testing, the assimilation of AIRS data into the forecast model is expected to result in major forecast improvements. Launch of AIRS on the EOS AQUA is scheduled for May 2001.

  5. Sensitivity Analysis for Atmospheric Infrared Sounder (AIRS) CO2 Retrieval

    NASA Technical Reports Server (NTRS)

    Gat, Ilana

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a thermal infrared sensor able to retrieve the daily atmospheric state globally for clear as well as partially cloudy field-of-views. The AIRS spectrometer has 2378 channels sensing from 15.4 micrometers to 3.7 micrometers, of which a small subset in the 15 micrometers region has been selected, to date, for CO2 retrieval. To improve upon the current retrieval method, we extended the retrieval calculations to include a prior estimate component and developed a channel ranking system to optimize the channels and number of channels used. The channel ranking system uses a mathematical formalism to rapidly process and assess the retrieval potential of large numbers of channels. Implementing this system, we identifed a larger optimized subset of AIRS channels that can decrease retrieval errors and minimize the overall sensitivity to other iridescent contributors, such as water vapor, ozone, and atmospheric temperature. This methodology selects channels globally by accounting for the latitudinal, longitudinal, and seasonal dependencies of the subset. The new methodology increases accuracy in AIRS CO2 as well as other retrievals and enables the extension of retrieved CO2 vertical profiles to altitudes ranging from the lower troposphere to upper stratosphere. The extended retrieval method for CO2 vertical profile estimation using a maximum-likelihood estimation method. We use model data to demonstrate the beneficial impact of the extended retrieval method using the new channel ranking system on CO2 retrieval.

  6. Development and test of the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Morse, Paul G.; Bates, Jerry C.; Miller, Christopher R.; Chahine, Moustafa T.; O'Callaghan, Fred; Aumann, Hartmut H.; Karnik, Avinash R.

    1999-12-01

    The Atmospheric Infrared Sounder (AIRS) has been developed for the NASA Earth Observing System (EOS) program for a scheduled launch on the EOS PM-1 spacecraft in December 2000. AIRS, working in concert with complementary microwave instrumentation on EOS PM-1 is designed to provide both new and more accurate data about the atmosphere, land and oceans for application to NASA climate studies and NOAA and DOD weather prediction. Among the important parameters to be derived from AIRS observations are atmospheric temperature profiles with an average accuracy of 1 K in 1 kilometer (km) layers in the troposphere, humidity profiles to 10% accuracy and surface temperatures with an average accuracy of 0.5 K. The AIRS measurement technique is based on passive IR remote sensing using a precisely calibrated, high spectral resolution grating spectrometer operating in the 3.7 - 15.4 micrometer region. The instrument concept uses a passively cooled multi- aperture echelle array spectrometer approach in combination with advanced state of the art focal plane and cryogenic refrigerator technology to achieve unparalleled performance capability in a practical long life configuration. The AIRS instrument, which has been under development since 1991, has been fully integrated and has completed successfully a comprehensive performance verification program. Performance verification included thermal vacuum testing, environmental qualification and a full range of spatial, spectral and radiometric calibrations, which have demonstrated outstanding spectrometric performance. This paper provides a brief overview of the AIRS mission and instrument design along with key results from the test program.

  7. Ultraspectral Infrared Measurements from the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas

    2003-01-01

    Aqua measures the Earth's water cycle, energy fluxes, vegetation and temperatures. The Atmospheric Infrared Sounder (AIRS), Advanced Microwave Sounding Unit (AMSU) and Humidity Sounder for Brazil (HSB) were launched on the EOS Aqua spacecraft in May 2002. AIRS has had good radiometric and spectral sensitivity, stability, and accuracy and is suitable for climate studies. Temperature products compare well with radiosondes and models over the limited test range (|LAT| less than 40 degrees). Early trace gas products demonstrate the potential of AIRS. NASA is developing the next generation of hyperspectral IR imagers. JPL is ready to participate with US government agencies and US industry to transfer AIRS technology and science experience.

  8. Regional Assimilation of NASA Atmospheric Infrared Sounder (AIRS) Data

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Lapenta, William; Jediovec, Gary J.; McCarty, William; Mecikalski, John R.

    2004-01-01

    The NASA Short-term Prediction Research and Transition (SPORT) Center seeks to accelerate the infusion of NASA Earth Science Enterprise (ESE) observations, data assimilation and modeling research into NW S forecast operations and decision-making. The Atmospheric Infrared Sounder (AIRS), is expected to advance climate research and weather prediction into the 21 st century. It is one of six instruments onboard Aqua, a satellite that is part of NASA s Earth Observing System. AIRS, along with two partner microwave sounding instruments, represents the most advanced atmospheric sounding system ever deployed in space. The system is capable of measuring the atmospheric temperature in the troposphere with radiosonde accuracies of 1 K over 1 km-thick layers under both clear and cloudy conditions, while the accuracy of the derived moisture profiles will exceed that obtained by radiosondes. It is imperative that the scientific community is prepared to take full advantage of next-generation satellite data that will become available within the next decade. The purpose of this paper is to describe a procedure designed to optimally assimilate AIRS data at high spatial resolution over both land and ocean. The assimilation system used in this study is the Local Analysis and Prediction System (LAPS) developed at the Forecast System Laboratory used extensively around the globe. Results will focus on quality control issues associated with AIRS, optimal assimilation strategies, and the impact of the AIRS data on subsequent numerical forecasts at 12 km produced by the next generation Weather Research and Forecast (WRF) model.

  9. Atmospheric infrared sounder on AIRS with emphasis on level 2 products

    NASA Technical Reports Server (NTRS)

    Lee, Sung-Yung; Fetzer, Eric; Granger, Stephanie; Hearty, Thomas; Lambrigtsen, Bjorn; Manning, Evan M.; Olsen, Edward; Pagano, Thomas

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched aboard EOS Aqua in May of 2002. AIRS is a grating spectrometer with almost 2400 channels covering the 3.74 to 15.40 micron spectral region with a nominal spectral resolution ((nu)/(delta)(nu)) of 1200, with some gaps. In addition, AIRS has 4 channels in the NIR/VIS region. The AIRS operates in conjunction with the microwave sounders Advanced Microwave Sounding Unit (AMSU-A) and Humidity Sounder of Brazil (HSB). The microwave sounders are mainly used for cloud clearing of IR radiances, or to remove the effect of cloud on the IR radiances.

  10. Development of Level 3 (gridded) products for the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie L.; Leroy, Stephen S.; Manning, Evan M.; Fetzer, Eric J.; Oliphant, Robert B.; Braverman, Amy; Lee, Sung-Yung; Lambrigtsen, Bjom H.

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) sounding system is a suite of infrared and microwave instruments flown as part of NASA's Earth Observing System (EOS) onboard the Aqua platform. The AIRS dataset provides a daily, global view of Earth processes at a finer vertical resolution than ever before. However, analysis of the AIRS data is a daunting task given the sheer volume and complexity of the data. The volume of data produced by the EOS project is unprecedented; the AIRS project alone will produce many terabytes of data over the lifetime of the mission. This paper describes development of AIRS Level 3 data products that will help to alleviate problems of access and usability.

  11. Level 1B products from the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, H. H.; Overoye, Ken

    2003-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched May 4, 2002 on the EOS Aqua Spacecraft. A discussion is given of the objectives of the AIRS experiment, including requirements on the data products. We summarize the instrument characteristics, including sensitivity, noise, and spectral response, and preflight calibration results leading to the estimate of the calibration accuracy. The Level 1B calibration algorithm is presented as well as the results of in-flight stability and sensitivity measurements.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  13. Improved Products for Assimilation and Model Validation from the Atmospheric Infrared Sounder (AIRS) on Aqua

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2008-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 micrometer spectral region with spectral resolution of better than 1200. Key channels from the AIRS Level 1B calibrated radiance product are currently assimilated into operational weather forecasts at NCEP and other international agencies. Additional Level 2 products for assimilation include the AIRS cloud cleared radiances and the geophysical retrieved temperature and water vapor profiles. The AIRS products are also used to validate climate model vertical and horizontal biases and transport of water vapor and key trace gases including Carbon Dioxide and Ozone. The wide variety of products available from the AIRS make it well suited to study processes affecting the interaction of these products.

  14. Science Highlights and Lessons Learned from the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Fetzer, Eric J.; Suda, Jarrod; Licata, Steve

    2011-01-01

    The Atmospheric Infrared Sounder (AIRS) and companion instrument, the Advanced Microwave Sounding Unit (AMSU) on the NASA Earth Observing System Aqua spacecraft are facility instruments designed to support measurements of atmospheric temperature, water vapor and a wide range of atmospheric constituents in support of weather forecasting and scientific research in climate and atmospheric chemistry. This paper is an update to the science highlights from a paper by the authors released last year and also looks back at the lessons learned and future needs of the scientific community. These lessons not only include requirements on the measurements, but scientific shortfalls as well. Results from the NASA Science Community Workshop in IR and MW Sounders relating to AIRS and AMSU requirements and concerns are covered and reflect much of what has been learned and what is needed for future atmospheric sounding from Low Earth Orbit.

  15. Atmospheric Infrared Sounder (AIRS) High Spectral Resolution Radiance Climate-Quality Dataset for Validating Climate Analyses

    NASA Astrophysics Data System (ADS)

    Goldberg, M.; Zhou, L.; Liu, X.; Cheng, Z.

    2009-12-01

    There is growing consensus that persistent and increasing anthropogenic emissions, since the beginning of the industrial revolution in the 19th century, are increasing atmospheric temperatures, increasing sea levels, melting ice caps and glaciers, increasing the occurrence of severe weather, and causing regional shifts in precipitation patterns. Changes in these parameters or occurrences are responses to changes in climate forcing terms, notably greenhouse gases. The NASA Atmospheric InfraRed Sounder (AIRS), launched in May of 2002, is the first high spectral resolution infrared sounder with nearly complete global coverage on a daily basis. High spectral resolution in the infrared provides sensitivity to nearly all climate forcings, responses and feedbacks. The AIRS radiances are sensitive to changes in carbon dioxide, methane, carbon monoxide, ozone, water vapor, temperature, clouds, aerosols, and surface characteristics, and also have been demonstrated through intercomparisons with airborne interferometers and with the EUMETSAT Infrared Atmospheric Sounding Interferometer(IASI) to have excellent accuracy, stability and precision. Such "benchmark" attributes are important for validating climate models and analyses. The AIRS data are applied to generate the first ever spectrally resolved infrared radiance (SRIR) dataset (2002- 2006) for monitoring changes in atmospheric temperature and constituents and for assessing the accuracy of climate and weather model analyses and forecasts. The SRIR dataset is a very powerful climate application. Spectral signatures derived from the dataset confirmed the largest depletion of ozone over the Arctic in 2005, and also verified that the European Center for Medium Range Weather (ECMWF) model analysis water vapor fields are significantly more accurate than the analyses of the National Centers for Environmental Prediction (NCEP). The NCEP moisture fields are generally 20% more moist than those from ECMWF. Applications included

  16. Hurricane Katrina as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1: click on image for larger AIRS microwave image

    At 1:30 a.m. local time this morning, the remnants of (now Tropical Depression) Katrina were centered on the Mississippi-Tennessee border. This microwave image from the Atmospheric Infrared Sounder instrument on NASA's Aqua spacecrat shows that the area of most intense precipitation was concentrated to the north of the center of activity.

    The infrared image shows how the storms look through an AIRS Infrared window channel. Window channels measure the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures are associated with high, cold cloud tops that make up the top of the hurricane. The infrared signal does not penetrate through clouds, so the purple color indicates the cool cloud tops of the storm. In cloud-free areas, the infrared signal is retrieved at the Earth's surface, revealing warmer temperatures. Cooler areas are pushing to purple and warmer areas are pushing to red.

    The microwave image (figure 1) reveals where the heaviest precipitation in the hurricane is taking place. The blue areas within the storm show the location of this heavy precipitation. Blue areas outside of the storm where there are moderate or no clouds are where the cold (in the microwave sense) sea surface shines through.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard

  17. Improved Impact of Atmospheric Infrared Sounder (AIRS) Radiance Assimilation in Numerical Weather Prediction

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Chou, Shih-Hung; Jedlovec, Gary

    2012-01-01

    Improvements to global and regional numerical weather prediction (NWP) have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) that mimics the analysis methodology, domain, and observational datasets for the regional North American Mesoscale (NAM) model run at the National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC) are run to examine the impact of each type of AIRS data set. The first configuration will assimilate the AIRS radiance data along with other conventional and satellite data using techniques implemented within the operational system; the second configuration will assimilate AIRS retrieved profiles instead of AIRS radiances in the same manner. Preliminary results of this study will be presented and focus on the analysis impact of the radiances and profiles for selected cases.

  18. Validation of the Atmospheric Infrared Sounder (AIRS) over the Antarctic Plateau: Low Radiance, Low Humidity, and Thin Clouds

    NASA Technical Reports Server (NTRS)

    Tobin, David C.

    2005-01-01

    The main goal of the project has been to use specialized measurements collected at the Antarctic Plateau to provide validation of the Atmospheric InfraRed Sounder (AIRS) spectral radiances and some AIRS Level 2 products. As proposed, efforts conducted at the University of Wisconsin are focused on providing technical information, data, and software in support of the validation studies.

  19. Carbon Monoxide Distribution over Peninsular Malaysia from the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Rajab, Jaso M.; MatJafri, M. Z.; Lim, H. S.; Abdullah, K.

    2009-07-01

    The Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua satellite. It daily coverage of ˜70% of the planet represents a significant evolutionary advance in satellite traces gas remote sensing. AIRS, the part of a large international investment to upgrade the operational meteorological satellite systems, is first of the new generation of meteorological advanced sounders for operational and research use, Providing New Insights into Weather and Climate for the 21st Century. Carbon monoxide (CO) is a ubiquitous, an indoor and outdoor air pollutant, is not a significant greenhouse gas as it absorbs little infrared radiation from the Earth. However, it does have an influence on oxidization in the atmosphere through interaction with hydroxyl radicals (OH), which also react with methane, halocarbons and tropospheric ozone. It produced by the incomplete combustion of fossil fuels and biomass burning, and that it has a role as a smog. The aim of this investigation is to study the (CO) carbon monoxide distribution over Peninsular Malaysia. The land use map of the Peninsular Malaysia was conducted by using CO total column amount, obtained from AIRS data, the map & data was processed and analyzed by using Photoshop & SigmaPlot 11.0 programs and compared for timing of various (day time) (28 August 2005 & 29 August 2007) for both direct comparison and the comparison using the same a priori profile, the CO concentrations in 28/8/2005 higher. The CO maps were generated using Kriging Interpolation technique. This interpolation technique produced high correlation coefficient, R2 and low root mean square error, RMS for CO. This study provided useful information for influence change of CO concentration on varies temperature.

  20. Atmospheric Infrared Sounder (AIRS) sounding evaluation and analysis of the pre-convective environment

    NASA Astrophysics Data System (ADS)

    Botes, Danelle; Mecikalski, John R.; Jedlovec, Gary J.

    2012-05-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral instrument onboard the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS) Aqua satellite. This study investigates the performance of AIRS soundings in characterizing the stability in the pre-convective environment of the southeastern United States. AIRS soundings are collocated with radiosonde observations within ±1 degree and 2 h of the Aqua overpass. For each case, the AIRS sounding with maximum PBest quality indicator (signifying the pressure level above which the sounding is of best quality) is chosen for analysis. Rapid Update Cycle soundings from 1800 UTC analyses are used to evaluate the results from AIRS. Precipitable water and stability indices including convective available potential energy, convective inhibition, Lifted Index, K-Index, and Total Totals are derived from all soundings. Results indicate that AIRS underestimates instability due to a dry bias at the surface and roughly 900 hPa. A simple method is presented for reconstructing a RAOB-like inversion (in terms of magnitude and altitude) within AIRS soundings, hence developing more representative RAOB-like soundings that can benefit the operational forecaster.

  1. Improving Regional Forecast by Assimilating Atmospheric InfraRed Sounder (AIRS) Profiles into WRF Model

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and produce improved forecasts. One such source comes from the Atmospheric InfraRed Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The purpose of this paper is to describe a procedure to optimally assimilate high resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background type, and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics. The AIRS thermodynamic profiles are derived from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators were used to select the highest quality temperature and moisture data for each profile location and pressure level. The analyses were then used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impacts of AIRS profiles on forecast were assessed against verifying NAM analyses and stage IV precipitation data.

  2. Data Assimilation and Regional Forecasts Using Atmospheric InfraRed Sounder (AIRS) Profiles

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Bradley; Jedlovec, Gary

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radiosondes. The purpose of this paper is to describe a procedure to optimally assimilate AIRS thermodynamic profiles--obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm-into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses will be used to conduct a month-long series of regional forecasts over the continental U.S. The long-tern1 impact of AIRS profiles on forecast will be assessed against verifying radiosonde and stage IV precipitation data.

  3. Data Assimilation and Regional Forecasts using Atmospheric InfraRed Sounder (AIRS) Profiles

    NASA Technical Reports Server (NTRS)

    Zabodsky, Brad; Chou, Shih-Hung; Jedlovec, Gary J.

    2009-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses, which in turn should lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which, together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with an accuracy comparable to that of radionsondes. The purpose of this poster is to describe a procedure to optimally assimilate AIRS thermodynamic profiles, obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm, into a regional configuration of the Weather Research and Forecasting (WRF) model using WRF-Var. The poster focuses on development of background error covariances for the regional domain and background field type, a methodology for ingesting AIRS profiles as separate over-land and over-water retrievals with different error characteristics, and utilization of level-by-level quality indicators to select only the highest quality data. The assessment of the impact of the AIRS profiles on WRF-Var analyses will focus on intelligent use of the quality indicators, optimized tuning of the WRF-Var, and comparison of analysis soundings to radiosondes. The analyses are used to conduct a month-long series of regional forecasts over the continental U.S. The long-term impact of AIRS profiles on forecast will be assessed against NAM analyses and stage IV precipitation data.

  4. Local, regional, and global views of tropospheric carbon monoxide from the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    McMillan, W. Wallace; Yurganov, Leonid

    2008-04-01

    More than five years of CO retrievals from the Atmospheric InfraRed Sounder (AIRS) onboard NASA's Aqua satellite reveal variations in tropospheric CO on timescales from twelve hours to five years and on spatial scales from local to global. The shorter timescales are invaluable to monitor daily variations in CO emissions, to enable three-dimensional tracking of atmospheric motions, and to enhance insights into atmospheric mixing. Previous studies have utilized AIRS CO retrievals over the course of days to weeks to track plumes from large forest fires. On the local scale, we will present AIRS observations of pollution from several northern hemisphere Megacities. On the regional scale, we will present AIRS observations of the Mexico City pollution plume. We will illustrate global scale AIRS CO observations of interannual variations linked to the influence of large-scale atmospheric perturbations from the El Nino Southern Oscillation (ENSO). In particular, we observe a quasi-biennial variation in CO emissions from Indonesia with varying magnitudes in peak emission occurring in 2002, 2004, and 2006. Examining satellite rainfall measurements over Indonesia, we find the enhanced CO emission correlates with occasions of less rainfall during the month of October. Continuing this satellite record of tropospheric CO with measurements from the European IASI instrument will permit construction of a long time-series useful for further investigations of climatological variations in CO emissions and their impact on the health of the atmosphere.

  5. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) and SeaWinds

    NASA Technical Reports Server (NTRS)

    2004-01-01

    this combination image, the AIRS infrared data reveals the temperature of the atmosphere around the storm, but doesn't tell us about the wind direction or relative intensity. The directional vectors of the SeaWinds data set show how the air is circulating around the storm.

    Scatterometers measure surface wind speed and direction by bouncing microwave pulses off the ocean's surface. The SeaWinds instruments measure the backscattered radar energy from wind-generated ocean waves. By making multiple measurements from different looks at the same location, we can infer the vector wind averaged over each 25 km resolution cell. The primary mission objective of the SeaWinds and QuikSCAT scatterometers is to obtain long-term, global coverage of the ocean vector winds for oceanographic and climate research. While not specifically designed for detailed mapping and tracking of hurricanes, both instruments have been found to be useful resources for operational forecasters.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  6. Impact of Atmospheric Infrared Sounder (AIRS) Thermodynamic Profiles on Regional Weather Forecasting

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Bradley T.; Jedlovee, Gary J.

    2010-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles with accuracy comparable to that of radiosondes. The purpose of this paper is to describe a procedure to assimilate AIRS thermodynamic profile data into a regional configuration of the Advanced Research Weather Research and Forecasting (WRF-ARW) model using its three-dimension variational (3DVAR) analysis component (WRF-Var). Quality indicators are used to select only the highest quality temperature and moisture profiles for assimilation in both clear and partly cloudy regions. Separate error characteristics for land and water profiles are also used in the assimilation process. Assimilation results indicate that AIRS profiles produce an analysis closer to in situ observations than the background field. Forecasts from a 37-day case study period in the winter of 2007 show that AIRS profile data can lead to improvements in 6-h cumulative precipitation forecasts due to instability added in the forecast soundings by the AIRS profiles. Additionally, in a convective heavy rainfall event from February 2007, assimilation of AIRS profiles produces a more unstable boundary layer resulting in enhanced updrafts in the model. These updrafts produce a squall line and precipitation totals that more closely reflect ground-based observations than a no AIRS control forecast. The location of available high-quality AIRS profiles ahead of approaching storm systems is found to be of paramount importance to the amount of impact the observations will have on the resulting forecasts.

  7. The Impact of Atmospheric InfraRed Sounder (AIRS) Profiles on Short-term Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Chou, Shih-Hung; Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

    2007-01-01

    The Atmospheric Infrared Sounder (AIRS), together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced spacebased atmospheric sounding systems. The combined AlRS/AMSU system provides radiance measurements used to retrieve temperature profiles with an accuracy of 1 K over 1 km layers under both clear and partly cloudy conditions, while the accuracy of the derived humidity profiles is 15% in 2 km layers. Critical to the successful use of AIRS profiles for weather and climate studies is the use of profile quality indicators and error estimates provided with each profile Aside form monitoring changes in Earth's climate, one of the objectives of AIRS is to provide sounding information of sufficient accuracy such that the assimilation of the new observations, especially in data sparse region, will lead to an improvement in weather forecasts. The purpose of this paper is to describe a procedure to optimally assimilate highresolution AIRS profile data in a regional analysis/forecast model. The paper will focus on the impact of AIRS profiles on a rapidly developing east coast storm and will also discuss preliminary results for a 30-day forecast period, simulating a quasi-operation environment. Temperature and moisture profiles were obtained from the prototype version 5.0 EOS science team retrieval algorithm which includes explicit error information for each profile. The error profile information was used to select the highest quality temperature and moisture data for every profile location and pressure level for assimilation into the ARPS Data Analysis System (ADAS). The AIRS-enhanced analyses were used as initial fields for the Weather Research and Forecast (WRF) system used by the SPORT project for regional weather forecast studies. The ADASWRF system will be run on CONUS domain with an emphasis on the east coast. The preliminary assessment of the impact of the AIRS profiles will focus on quality control issues associated with AIRS

  8. Hurricane Frances as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS) - Total Water

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Born in the Atlantic, Hurricane Frances became a category 4 hurricane on August 31, 2004. Expectations are the hurricane will hit the Space Coast of Florida in Brevard County early Sunday morning.

    This movie is a time-series of maps that show AIRS observations of the total amount of water vapor present in the atmospheric column above each point of the Earth's surface. If all the water vapor in the column were forced to fall as rain, the depth of the resulting puddle on the surface at that point is equal to the value shown on the map. Fifty millimeters (mm) is about 2 inches. The large band of maximum water vapor in the neighborhood of the equator is the Intertropical Convergence Zone (ITCZ), a region of strong convection and powerful thunderstorms.

    This movie shows the total precipitable water vapor from August 23 through September 2, 2004. You can see Hurricane Frances as it moves through the Caribbean toward Florida, and the changes in intensity are visible. The eye has been marked with a red spot. The water vapor encompassed by the hurricane is also the result of the very strong convection which is an integral part of the formation and intensification of tropical storms. If you look at the last frame of the movie in the lower right corner, you can see the emergence of a new tropical storm. Ivan makes its debut in the Atlantic.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft

  9. Impact of Atmospheric Infrared Sounder (AIRS) Thermodynamic Profiles on Regional Precipitation Forecasting

    NASA Technical Reports Server (NTRS)

    Chou, S.-H.; Zavodsky, B. T.; Jedloved, G. J.

    2010-01-01

    In data sparse regions, remotely-sensed observations can be used to improve analyses and lead to better forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), provides temperature and moisture profiles in clear and cloudy regions with accuracy which approaches that of radiosondes. The purpose of this paper is to describe an approach to assimilate AIRS thermodynamic profile data into a regional configuration of the Advanced Research WRF (ARW) model using WRF-Var. Quality indicators are used to select only the highest quality temperature and moisture profiles for assimilation in clear and partly cloudy regions, and uncontaminated portions of retrievals above clouds in overcast regions. Separate error characteristics for land and water profiles are also used in the assimilation process. Assimilation results indicate that AIRS profiles produce an analysis closer to in situ observations than the background field. Forecasts from a 37-day case study period in the winter of 2007 show that AIRS profile data can lead to improvements in 6-h cumulative precipitation forecasts resulting from improved thermodynamic fields. Additionally, in a convective heavy rainfall event from February 2007, assimilation of AIRS profiles produces a more unstable boundary layer resulting in enhanced updrafts in the model. These updrafts produce a squall line and precipitation totals that more closely reflect ground-based observations than a no AIRS control forecast. The location of available high-quality AIRS profiles ahead of approaching storm systems is found to be of paramount importance to the amount of impact the observations will have on the resulting forecasts.

  10. Spaceborne Infrared Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas; Macenka, Steven; Kampe, Thomas

    2004-01-01

    A report describes the development of the spaceborne infrared atmospheric sounder (SIRAS) - a spectral imaging instrument, suitable for observing the atmosphere of the Earth from a spacecraft, that utilizes four spectrometers to cover the wavelength range of 12 to 15.4 m with a spectral resolution that ranges between 1 part per 900 and 1 part per 1,200 in wavelength. The spectrometers are operated in low orders to minimize filtering requirements. Focal planes receive the dispersed energy and provide a spectrum of the scene. The design of the SIRAS combines advanced, wide-field refractive optics with high-dispersion gratings in a solid-state (no moving parts), diffraction-limited optical system that is the smallest such system that can be constructed for the specified wavelength range and resolution. The primary structure of the SIRAS has dimensions of 10 by 10 by 14 cm and has a mass of only 2.03 kg

  11. The impact of atmospheric infrared sounder (AIRS) profiles on short-term weather forecasts

    NASA Astrophysics Data System (ADS)

    Zavodsky, Bradley T.; Chou, Shih-Hung; Jedlovec, Gary; Lapenta, William

    2007-04-01

    The Atmospheric Infrared Sounder (AIRS), together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. Aside from monitoring changes in Earth's climate, one of the objectives of AIRS is to provide sounding information with sufficient accuracy such that the assimilation of the new observations, especially in data sparse regions, will lead to an improvement in weather forecasts. The combined AIRS/AMSU system provides radiance measurements used as input to a sophisticated retrieval scheme which has been shown to produce temperature profiles with an accuracy of 1 K over 1 km layers and humidity profiles with accuracy of 10-15% in 2 km layers in both clear and partly cloudy conditions. The retrieval algorithm also provides estimates of the accuracy of the retrieved values at each pressure level, allowing the user to select profiles based on the required error tolerances of the application. The purpose of this paper is to describe a procedure to optimally assimilate high-resolution AIRS profile data in a regional analysis/forecast model. The paper focuses on a U.S. East-Coast cyclone from November 2005. Temperature and moisture profiles-containing information about the quality of each temperature layer-from the prototype version 5.0 Earth Observing System (EOS) science team retrieval algorithm are used in this study. The quality indicators are used to select the highest quality temperature and moisture data for each profile location and pressure level. AIRS data are assimilated into the Weather Research and Forecasting (WRF) numerical weather prediction model using the Advanced Regional Prediction System (ARPS) Data Analysis System (ADAS), to produce near-real-time regional weather forecasts over the continental U.S. The preliminary assessment of the impact of the AIRS profiles will focus on intelligent use of the quality indicators, analysis impact, and forecast verification against rawinsondes

  12. Estimation of Greenland's Ice Cover Melting Area Using the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Imbiriba, B.; Desouza-Machado, S. G.; Hannon, S.; Strow, L. L.

    2012-12-01

    Using the Atmospheric Infrared Sounder (AIRS), we are able to detect the melting of Greenland's ice cover for the July 12, 2012 warming event and estimate the corresponding fractional melted area. We collect all of AIRS' overpasses above Greenland, using the reflected solar radiation to avoid cloudy scenes. We perform a retrieval of the skin surface temperature in order to classify a scene as likely frozen (skin temperature well below the freezing point), likely melted (skin temperature well above freezing point), or thawing. Using empirical snow and water emissivity data we retrieve an effective scene snow/water fraction. For this day we estimate that 90% of the ice cover exhibits some thawing and that 53% of the ice cover area was effectivelly covered with liquid water. For contrast we also look at July 8, 2012, and verify that most of the island, 68%, was frozen at that date. We also see a correlation of the thawing area with the solar angle as the day progresses.

  13. Characterization and validation of methane products from the Atmospheric Infrared Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Xiong, Xiaozhen; Barnet, Chris; Maddy, Eric; Sweeney, Colm; Liu, Xingpin; Zhou, Lihang; Goldberg, Mitch

    2008-09-01

    This paper presents the characterization and validation of retrievals of atmospheric methane (CH4) vertical profiles by the Atmospheric Infrared Sounder (AIRS) on the EOS/Aqua platform. AIRS channels near 7.6 μm are used for CH4 retrieval, and they are most sensitive to the middle to upper troposphere, i.e., about 200-300 hPa in the tropics and 400-500 hPa in the polar region. The atmospheric temperature-humidity profiles, surface skin temperature, and emissivity required to derive CH4 are obtained from retrievals using separate AIRS channels and the Advanced Microwave Sounding Unit (AMSU). Comparison of AIRS retrieved profiles with some in situ aircraft CH4 profiles implied that the forward model used in the AIRS retrieval system V4.0 required a 2% increase in methane absorption coefficients for strong absorption channels, and this bias adjustment was implemented in the AIRS retrieval system V5.0. As a new operational product in V5.0, AIRS CH4 were validated using in situ aircraft observations at 22 sites of the NOAA Earth System Research Laboratory, Global Monitoring Division (NOAA/ESRL/GMD), ranging from the Arctic to the tropical South Pacific Ocean, but their altitudes are usually above 300 hPa. The results show the bias of the retrieved CH4 profiles for this version is -1.4˜0.1% and its RMS difference is about 0.5-1.6%, depending on altitude. These validation comparisons provide critical assessment of the retrieval algorithm and will continue using more in situ observations together with future improvement to the retrieval algorithm. AIRS CH4 products include not only the CH4 profile but also the information content. As examples, the products of AIRS CH4 in August 2004 and the difference of CH4 in May and September 2004 are shown. From these results a few features are evident: (1) a large AIRS CH4 plume southwest of the Tibetan plateau that may be associated with deep convection during the Asian summer monsoon; (2) high mixing ratios of AIRS CH4 in

  14. Comparison of Methane Data Products from the TES and AIRS Infrared Sounders

    NASA Astrophysics Data System (ADS)

    Pagano, T. J.; Pagano, T. S.; Worden, J. R.

    2015-12-01

    Methane is the second most powerful greenhouse gas with a highly positive radiative forcing of 0.48 W/m2 (IPCC 2013). Global concentrations of methane have been steadily increasing since 2007 (Bruhwiler 2014), raising concerns about methane's impact on the future global climate. For about the last decade, the Tropospheric Emission Spectrometer (TES) on the Earth Observing System (EOS) Aura spacecraft has been detecting several trace gas species in the troposphere including methane. The goal of this study is to compare TES methane retrievals to that of the Atmospheric Infrared Sounder (AIRS) on the EOS Aqua spacecraft so that scientific investigations may be transferred from TES to AIRS. The two instruments fly in the afternoon constellation (A-Train), providing numerous coincident measurements for comparison. In addition, they also have a similar spectral range, (3.3 to 15.4 µm) for TES (Beer, 2006) and (3.7 to 15.4 µm) for AIRS (Chahine, 2006), making both instruments sensitive to the mid and upper troposphere. This makes them ideal candidates to compare methane data products. However, because AIRS spectral resolution is lower than that of the TES, there may be a difference in vertical sensitivity. In addition, the retrieval techniques and error characteristics are different for the two data sets. The current state of validation for these data products will be presented. To identify conditions in which the data sets agree and dis agree, we present global maps of methane concentrations from monthly level 3 (L3) data products. We also investigate the temporal stability between the two datasets by comparing global zonal averages derived from L3 over the last decade. Finally, we compare L2 retrieval profiles from representative granules in the tropical, mid-latitude and northern latitudes.

  15. Regional Precipitation Forecast with Atmospheric InfraRed Sounder (AIRS) Profile Assimilation

    NASA Technical Reports Server (NTRS)

    Chou, S.-H.; Zavodsky, B. T.; Jedloved, G. J.

    2010-01-01

    Advanced technology in hyperspectral sensors such as the Atmospheric InfraRed Sounder (AIRS; Aumann et al. 2003) on NASA's polar orbiting Aqua satellite retrieve higher vertical resolution thermodynamic profiles than their predecessors due to increased spectral resolution. Although these capabilities do not replace the robust vertical resolution provided by radiosondes, they can serve as a complement to radiosondes in both space and time. These retrieved soundings can have a significant impact on weather forecasts if properly assimilated into prediction models. Several recent studies have evaluated the performance of specific operational weather forecast models when AIRS data are included in the assimilation process. LeMarshall et al. (2006) concluded that AIRS radiances significantly improved 500 hPa anomaly correlations in medium-range forecasts of the Global Forecast System (GFS) model. McCarty et al. (2009) demonstrated similar forecast improvement in 0-48 hour forecasts in an offline version of the operational North American Mesoscale (NAM) model when AIRS radiances were assimilated at the regional scale. Reale et al. (2008) showed improvements to Northern Hemisphere 500 hPa height anomaly correlations in NASA's Goddard Earth Observing System Model, Version 5 (GEOS-5) global system with the inclusion of partly cloudy AIRS temperature profiles. Singh et al. (2008) assimilated AIRS temperature and moisture profiles into a regional modeling system for a study of a heavy rainfall event during the summer monsoon season in Mumbai, India. This paper describes an approach to assimilate AIRS temperature and moisture profiles into a regional configuration of the Advanced Research Weather Research and Forecasting (WRF-ARW) model using its three-dimensional variational (3DVAR) assimilation system (WRF-Var; Barker et al. 2004). Section 2 describes the AIRS instrument and how the quality indicators are used to intelligently select the highest-quality data for assimilation

  16. Hurricane Ivan as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  17. Assimilation of Atmospheric InfraRed Sounder (AIRS) Profiles using WRF-Var

    NASA Technical Reports Server (NTRS)

    Zavodsky, Brad; Jedlovec, Gary J.; Lapenta, William

    2008-01-01

    The Weather Research and Forecasting (WRF) model contains a three-dimensional variational (3DVAR) assimilation system (WRF-Var), which allows a user to join data from multiple sources into one coherent analysis. WRF-Var combines observations with a background field traditionally generated using a previous model forecast through minimization of a cost function. In data sparse regions, remotely-sensed observations may be able to improve analyses and produce improved forecasts. One such source comes from the Atmospheric Infrared Sounder (AIRS), which together with the Advanced Microwave Sounding Unit (AMSU), represents one of the most advanced space-based atmospheric sounding systems. The combined AIRS/AMSU system provides radiance measurements used as input to a sophisticated retrieval scheme which has been shown to produce temperature profiles with an accuracy of 1 K over 1 km layers and humidity profiles with accuracy of 15% in 2 km layers in both clear and partly cloudy conditions. The retrieval algorithm also provides estimates of the accuracy of the retrieved values at each pressure level, allowing the user to select profiles based on the required error tolerances of the application. The purpose of this paper is to describe a procedure to optimally assimilate high-resolution AIRS profile data into a regional configuration of the Advanced Research WRF (ARW) version 2.2 using WRF-Var. The paper focuses on development of background error covariances for the regional domain and background field type using gen_be and an optimal methodology for ingesting AIRS temperature and moisture profiles as separate overland and overwater retrievals with different error characteristics in the WRF-Var. The AIRS thermodynamic profiles are obtained from the version 5.0 Earth Observing System (EOS) science team retrieval algorithm and contain information about the quality of each temperature layer. The quality indicators are used to select the highest quality temperature and moisture

  18. Evaluating the Impact of Atmospheric Infrared Sounder (AIRS) Data On Convective Forecasts

    NASA Technical Reports Server (NTRS)

    Kozlowski, Danielle; Zavodsky, Bradley

    2011-01-01

    The Short-term Prediction Research and Transition Center (SPoRT) is a collaborative partnership between NASA and operational forecasting partners, including a number of National Weather Service (NWS) offices. SPoRT provides real-time NASA products and capabilities to its partners to address specific operational forecast challenges. The mission of SPoRT is to transition observations and research capabilities into operations to help improve short-term weather forecasts on a regional scale. Two areas of focus are data assimilation and modeling, which can to help accomplish SPoRT's programmatic goals of transitioning NASA data to operational users. Forecasting convective weather is one challenge that faces operational forecasters. Current numerical weather prediction (NWP) models that operational forecasters use struggle to properly forecast location, timing, intensity and/or mode of convection. Given the proper atmospheric conditions, convection can lead to severe weather. SPoRT's partners in the National Oceanic and Atmospheric Administration (NOAA) have a mission to protect the life and property of American citizens. This mission has been tested as recently as this 2011 severe weather season, which has seen more than 300 fatalities and injuries and total damages exceeding $10 billion. In fact, during the three day period from 25-27 April, 1,265 storms reports (362 tornado reports) were collected making this three day period one of most active in American history. To address the forecast challenge of convective weather, SPoRT produces a real-time NWP model called the SPoRT Weather Research and Forecasting (SPoRT-WRF), which incorporates unique NASA data sets. One of the NASA assets used in this unique model configuration is retrieved profiles from the Atmospheric Infrared Sounder (AIRS).The goal of this project is to determine the impact that these AIRS profiles have on the SPoRT-WRF forecasts by comparing to a current operational model and a control SPoRT-WRF model

  19. Validation of the Atmospheric Infrared Sounder (AIRS) version 5 land surface emissivity product over the Namib and Kalahari deserts

    NASA Astrophysics Data System (ADS)

    Hulley, Glynn C.; Hook, Simon J.; Manning, Evan; Lee, Sung-Yung; Fetzer, Eric

    2009-10-01

    Hyperspectral infrared sounders require accurate knowledge of the land surface emissivity (LSE) to retrieve important climate variables such as surface temperature, air temperature, and total water vapor from space. This study provides a method for validating and assessing the Atmospheric Infrared Sounder (AIRS) version 5 LSE product using high-spatial resolution data (90 m) from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) which has five bands in the thermal infrared region (8-12 μm, 1250-833 cm-1) and high-spectral resolution laboratory measurements of sand samples collected over the Namib and Kalahari deserts in southern Africa. Results indicate that the mean, absolute daytime LSE difference between AIRS and the laboratory results for six wavelengths in window regions between 3.9 and 11.4 μm (2564-877 cm-1) was 2.3% over the Namib and 0.70% over the Kalahari, while the mean difference with ASTER was 2.3% over the Namib and 2.26% over the Kalahari for four bands between 8 and 12 μm. Systematic modeling and surface dependent AIRS LSE retrieval errors such as large discrepancies between day and nighttime shortwave LSE (up to 15%), unphysical values (LSE >1), and large daytime temporal variations in the shortwave region (up to 30%) are further discussed.

  20. Evaluation of the Impact of Atmospheric Infrared Sounder (AIRS) Radiance and Profile Data Assimilation in Partly Cloudy Regions

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

    2013-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of 6 weeks of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

  1. A multi-aperture spectrometer design for the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Pagano, Robert; Hatch, Marcus

    1990-01-01

    The baseline multiaperture echelle spectrometer for the Atmospheric IR Sounder (AIRS) is described in terms of design and applications. The functional requirements for the optical design are set forth including the 1-K measurement goal, the 3.4-15.4 spectral bandpass, and the full global coverage twice daily. The multiaperture spectrometer is compared to the cross-dispersed spectrometer, and the multiaperture model is found to permit specific adjustments to the signal-to-noise ratio. The optical design of the spectrometer is described in terms of the focal-plane constraints, the multiaperture pupil-imaging relay, the spectrometer collimator, and the grating format and efficiency. The multiaperture design is found to have a good spectral-response function, and a 1.2 percent signal change is noted for a 95-percent unpolarized scene. The AIRS instrument is illustrated in its deployment configuration and is concluded to be capable of fulfilling the performance requirements.

  2. Information-based mid-upper tropospheric methane derived from Atmospheric Infrared Sounder (AIRS) and its validation

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Barnet, C.; Wei, J.; Maddy, E.

    2009-07-01

    Atmospheric Infrared Sounder (AIRS) measurements of methane (CH4) generally contain about 1.0 degree of freedom and are therefore dependent on a priori assumptions about the vertical methane distribution as well as the temperature lapse rate and the amount of moisture. Thus it requires that interpretation and/or analysis of the CH4 spatial and temporal variation based on the AIRS retrievals need to use the averaging kernels (AK). To simplify the use of satellite retrieved products for scientific analysis, a method based on the information content of the retrievals is developed, in which the AIRS retrieved CH4 in the layer from 50 to 250 hPa below the tropopause is used to characterize the mid-upper tropospheric CH4 in the mid-high latitude regions. The basis of this method is that in the mid-high latitude regions the maximum sensitive layers of AIRS to CH4 have a good correlation with the tropopause heights, and these layers are usually between 50 and 250 hPa below the tropopause. Validation using the aircraft measurements from NOAA/ESRL/GMD and the campaigns INTEX-A and -B indicated that the correlation of AIRS mid-upper tropospheric CH4 with aircraft measurements is ~0.6-0.7, and its the bias and rms difference are less than ±1% and 1.2%, respectively. Further comparison of the CH4 seasonal cycle indicated that the cycle from AIRS mid-upper tropospheric CH4 is in a reasonable agreement with NOAA aircraft measurements. This method provides a simple way to use the thermal infrared sounders data to approximately analyze the spatial and temporal variation CH4 in the upper free tropospere without referring the AK. This method is applicable to derive tropospheric CH4 as well as other trace gases for any thermal infrared sensors.

  3. Global and Regional Seasonal Variability of Mid-Tropospheric CO2 as Measured by the Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.; Nguyen, Hai

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the Earth Observing System (EOS) Aqua Spacecraft, launched on May 4, 2002 into a near polar sun-synchronous orbit. AIRS has 2378 infrared channels ranging from 3.7 ?m to 15.4 ?m and a 13.5 km footprint at nadir. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy on a global scale, as well as water vapor profiles and trace gas amounts for CO2, CO, SO2, O3 and CH4. AIRS CO2 climatologies have been shown to be useful for identifying anomalies associated with geophysical events such as El Nino-Southern Oscillation or Madden-Julian oscillation. In this study, monthly representations of mid-tropospheric CO2 are constructed from 10 years of AIRS Version 5 monthly Level 3 data. We compare the AIRS mid-tropospheric CO2 representations to ground-based measurements from the Scripps and National Oceanic and Atmospheric Administration Climate Modeling and Diagnostics Laboratory (NOAA CMDL) ground networks to better understand the phase lag of the CO2 seasonal cycle between the surface and middle troposphere. Results show only a small phase lag in the tropics that grows to approximately two months in the northern latitudes.

  4. Radiometric consistency assessment of hyperspectral infrared sounders

    NASA Astrophysics Data System (ADS)

    Wang, L.; Han, Y.; Jin, X.; Chen, Y.; Tremblay, D. A.

    2015-07-01

    The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark datasets for both inter-calibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and -B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through one year of simultaneous nadir overpass (SNO) observations to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the longwave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1-0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both Polar and Tropical SNOs. The combined global SNO datasets indicate that, the CrIS-AIRS BT differences are less than or around 0.1 K among 21 of 25 comparison spectral regions and they range from 0.15 to 0.21 K in the remaining 4 spectral regions. CrIS-AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

  5. Radiometric consistency assessment of hyperspectral infrared sounders

    NASA Astrophysics Data System (ADS)

    Wang, L.; Han, Y.; Jin, X.; Chen, Y.; Tremblay, D. A.

    2015-11-01

    The radiometric and spectral consistency among the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared Sounder (CrIS) is fundamental for the creation of long-term infrared (IR) hyperspectral radiance benchmark data sets for both intercalibration and climate-related studies. In this study, the CrIS radiance measurements on Suomi National Polar-orbiting Partnership (SNPP) satellite are directly compared with IASI on MetOp-A and MetOp-B at the finest spectral scale and with AIRS on Aqua in 25 selected spectral regions through simultaneous nadir overpass (SNO) observations in 2013, to evaluate radiometric consistency of these four hyperspectral IR sounders. The spectra from different sounders are paired together through strict spatial and temporal collocation. The uniform scenes are selected by examining the collocated Visible Infrared Imaging Radiometer Suite (VIIRS) pixels. Their brightness temperature (BT) differences are then calculated by converting the spectra onto common spectral grids. The results indicate that CrIS agrees well with IASI on MetOp-A and IASI on MetOp-B at the long-wave IR (LWIR) and middle-wave IR (MWIR) bands with 0.1-0.2 K differences. There are no apparent scene-dependent patterns for BT differences between CrIS and IASI for individual spectral channels. CrIS and AIRS are compared at the 25 spectral regions for both polar and tropical SNOs. The combined global SNO data sets indicate that the CrIS-AIRS BT differences are less than or around 0.1 K among 21 of 25 spectral regions and they range from 0.15 to 0.21 K in the remaining four spectral regions. CrIS-AIRS BT differences in some comparison spectral regions show weak scene-dependent features.

  6. Retrieving dust aerosols properties (optical depth and altitude) from very high resolution infrared sounders : from AIRS to IASI.

    NASA Astrophysics Data System (ADS)

    Peyridieu, S.; Chédin, A.; Capelle, V.; Pierangelo, C.; Lamquin, N.; Armante, R.

    2009-04-01

    Observation from space, being global and quasi-continuous, is a first importance tool for aerosol studies. Remote sensing in the visible domain has been widely used to obtain better characterization of these particles and their effect on solar radiation. On the opposite, remote sensing of aerosols in the thermal infrared domain still remains marginal. However, knowledge of the effect of aerosols on terrestrial radiation is needed for the evaluation of their total radiative forcing. Infrared remote sensing provides a way to retrieve other aerosol characteristics, including their mean altitude. Moreover, observations are possible at night and day, over ocean and over land. In this context, six years (2003-2008) of the 2nd generation vertical sounder AIRS observations have been processed over the tropical belt (30°N-30°S). Aerosol properties (10 µm infrared optical depth and mean layer altitude) are retrieved using a Look-Up Table (LUT) approach. The forward radiative transfer model 4A (Automatized Atmospheric Absorption Atlas) coupled with the DISORT algorithm accounting for atmospheric diffusion is used to feed the LUTs with simulations of the brightness temperatures of AIRS channels selected for their sensitivity to dust aerosols. LUTs degrees of freedom are : instrument viewing angle, surface pressure and surface emissivity, a parameter particularly important for dust retrieval over bright surfaces, such as deserts. AODs (resp. altitude) are sampled over the range 0.0-0.8 (resp. 0-5800 m). The retrieval algorithm follows two main steps : (i) retrieval of the atmospheric situation observed (temperature and water vapour profiles) ; (ii) retrieval of aerosol properties. Results have been compared to instruments commonly used in aerosol studies and also part of the Aqua Train : MODIS/Aqua and CALIOP/CALIPSO. The agreement obtained from these comparisons is quite satisfactory, demonstrating that our algorithm effectively allows the simultaneous retrieval of dust AOD

  7. Hurricane Ivan as Observed by NASA's Spaceborne Atmospheric Infrared Sounder (AIRS)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Microwave 89Ghz imageFigure 2: Visible/near infrared sensor

    Hurricane Ivan is the most powerful hurricane to hit the Caribbean in 10 years. On September 7 and 8 it damaged 90 percent of the homes in Grenada and killed at least 16 people as it swept over Grenada, Barbados and the other islands in the area. By Thursday morning on September 9, Ivan's sustained winds reached 160 mph making it a rare category 5 hurricane on the Saffir-Simpson scale. By Monday September 13, Ivan is blamed for 67 deaths and skirts western Cuba with winds clocked at 156 mph. The National Hurricane Center predicted the eye of Ivan will make landfall across Mobile Bay in Alabama late Wednesday or early Thursday.

    These images of Hurricane Ivan were acquired by the AIRS infrared, microwave, and visible sensors on September 15 at 1:30 pm local time as the storm moves in to Alabama. Ivan at category 4 strength is about 150 miles south of Mobile, Alabama and is moving north at 14 mph. Maximum sustained winds are reported to be at 135 mph and extend 105 miles from the center, while tropical storm-force winds extend 290 miles from the center. Ivan pounded the Gulf coast all day Wednesday, and is expected to make landfall between midnight and 3am in Mobile Bay, Alabama.

    This image shows how the storm looks through an AIRS Infrared window channel, and reveals a very large eye - about 75 km (50 miles) across. Window channels measure the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures are associated with high, cold cloud tops that make up the top of the hurricane. The infrared signal does not penetrate through clouds, so the purple color indicates the cool cloud tops of the storm. In cloud-free areas, the infrared signal is retrieved at the Earth's surface, revealing warmer temperatures. Cooler areas are pushing to purple

  8. Atmospheric Infrared Sounder on the Earth Observing System

    SciTech Connect

    Aumann, H.H.; Pagano, R.J. . Jet Propulsion Lab.)

    1994-03-01

    Recent breakthroughs in IR detector array and cryocooler technology have made it possible to convert the concepts of optimum, passive, IR sounding to a practical satellite-borne instrument: the Atmospheric infrared Sounder (AIRS), a grating array IR spectrometer temperature sounder. AIRS, together with the Advanced Microwave Sounding Unit and the Microwave Humidity Sounder, will form a complementary sounding system for the Earth Observing System to be launched in the year 2000. The three instruments are expected to become the new operational sounding system for the National Oceanic and Atmospheric Administration.

  9. Operational readiness for the Atmospheric Infrared Sounder (AIRS) on the earth observing system aqua spacecraft

    NASA Technical Reports Server (NTRS)

    Pagano, T.; Aumann, H.; Chahine, M.; Karnik, A.; Goodson, G.; Schindler, R.; Elliot, D. A.; Hofstadter, M.

    2001-01-01

    This paper describes the AIRS science objectives, the instrument design and operation, the in-flight operational scenario, and the calibration plan. All aspects of the program are addressed here to demonstrate that the AIRS program is ready to transition to the flight segment of the program.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  11. The Atmospheric Infrared Sounder (AIRS) on Aqua: instrument stability and data products for climate observations

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, M.; Aumann, H.; Strow, L.; Broberg, S.; Gaiser, S.

    2003-01-01

    30th International Symposium on Remote Sensing of the Environment (ISRSE) NASA Honolulu, Hawaii, USAThis paper discusses the stability of the AIRS instrument as measured pre-flight and in-orbit. In order differentiate instrument related changes with true changes in climate observations, the instrument stability must be demonstrated.

  12. Atmospheric Infrared Sounder on the Earth Observing System

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.

    1995-01-01

    The Atmospheric Infrared Sounder (AIRS) is a high spectral resolution IR spectrometer. AIRS, together with the Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sounder (MHS), is designed to meet the operational weather prediction requirements of the National Oceanic and Atmospheric Administration (NOAA) and the global change research objectives of the National Aeronautics and Space Administration (NASA). The three instruments will be launched in the year 2000 on the EOS-PM spacecraft. Testing of the AIRS engineering model will start in 1996.

  13. The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua Spacecraft: A General Remote Sensing Tool for Understanding Atmospheric Structure, Dynamics and Composition

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Fetzer, Eric J.

    2010-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. Early in the mission, the AIRS instrument demonstrated its value to the weather forecasting community with better than 6 hours of improvement on the 5 day forecast. Now with over eight years of consistent and stable data from AIRS, scientists are able to examine processes governing weather and climate and look at seasonal and interannual trends from the AIRSdata with high statistical confidence. Naturally, long-term climate trends require a longer data set, but indications are that the Aqua spacecraft and the AIRS instrument should last beyond 2018. This paper briefly describes the AIRS data products and presents some of the most significant findings involving the use of AIRS data in the areas of weather forecast improvement, climate processes and model validation, cloud and polar processes, and atmospheric composition (chemistry and dust).

  14. The Atmospheric Infrared Sounder- An Overview

    NASA Technical Reports Server (NTRS)

    Larnbrigtsen, Bjorn; Fetzer, Eric; Lee, Sung-Yung; Irion, Fredrick; Hearty, Thomas; Gaiser, Steve; Pagano, Thomas; Aumann, Hartmut; Chahine, Moustafa

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) was launched in May 2002. Along with two companion microwave sensors, it forms the AIRS Sounding Suite. This system is the most advanced atmospheric sounding system to date, with measurement accuracies far surpassing those available on current weather satellites. The data products are calibrated radiances from all three sensors and a number of derived geophysical parameters, including vertical temperature and humidity profiles, surface temperature, cloud fraction, cIoud top pressure, and profiles of ozone. These products are generated under cloudy as well as clear conditions. An ongoing calibration validation effort has confirmed that the system is very accurate and stable, and many of the geophysical parameters have been validated. AIRS is in some cases more accurate than any other source and can therefore be difficult to validate, but this offers interesting new research opportunities. The applications for the AIRS products range from numerical weather prediction to atmospheric research - where the AIRS water vapor products near the surface and in the mid to upper troposphere will make it possible to characterize and model phenomena that are key for short-term atmospheric processes, such as weather patterns, to long-term processes, such as interannual cycles (e.g., El Nino) and climate change.

  15. On Cirrus Cloud Fields Measured by the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Eldering, Annmarie; Liou, Kuo Nan

    2006-01-01

    A viewgraph presentation showing trends in clouds measured by the Atmospheric Infrared Sounder (AIRS) is given. The topics include: 1) Trends in clouds measured by AIRS: Are they reasonable? 2) Single and multilayered cloud trends; 3) Retrievals of thin cirrus D(sub e) and tau: Single-layered cloud only; 4) Relationships between ECF, D(sub e), tau, and T(sub CLD); and 5) MODIS vs. AIRS retrievals.

  16. Large Scale Variability of Mid-Tropospheric Carbon Dioxide as Observed by the Atmospheric Infrared Sounder (AIRS) on the NASA EOS Aqua Platform

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 microns to 15.4 microns and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy, water vapor profiles (20%/2km), infrared cloud height and fraction, and trace gas amounts for CO2, CO, SO2, O3 and CH4 in the mid to upper troposphere. AIRS wide swath(cedilla) +/-49.5 deg , enables daily global daily coverage for over 95% of the Earth's surface. AIRS data are used for weather forecasting, validating climate model distribution and processes, and observing long-range transport of greenhouse gases. In this study, we examine the large scale and regional horizontal variability in the AIRS Mid-tropospheric Carbon Dioxide product as a function of season and associate the observed variability with known atmospheric transport processes, and sources and sinks of CO2.

  17. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Spackman, Ryan; Dickerson, Russell; Schoeberl, Mark; Bloom, Hal; Gordley, Larry; McHugh, Martin; Thompson, Anne; Burrows, John; Zeng, Ning; Marshall, Tom; Fish, Chad; Kim, Jhoon; Park, Rokjin; Warner, Juying; Bhartia, Pawan; Kollonige, Debra

    2013-04-01

    Climate change and air quality are the most pressing environmental issues of the 21st century for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  18. GRIPS - The Geostationary Remote Infrared Pollution Sounder

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Schoeberl, M. R.; Gordley, L. L.; McHugh, M. J.; Thompson, A. M.; Burrows, J. P.; Zeng, N.; Marshall, B. T.; Fish, C. S.; Spackman, J. R.; Kim, J.; Park, R.; Warner, J. X.; Bhartia, P. K.; Kollonige, D. E.

    2012-12-01

    Climate change and air quality are the most pressing environmental issues of the 21st century - for America and for the world as a whole. Despite decades of research, the sources and sinks of key greenhouse gases and other pollutants remain highly uncertain making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), and methane (CH4). By using measurements of nitrous oxide (N2O) and the O2 A-band to help correct for clouds and aerosols, GRIPS will achieve unprecedented precision. Together these gases account for about 85% of all climate forcing and they impact atmospheric ozone (O3). GRIPS, employing gas-filter correlation radiometry, uses the target gases themselves in place of dispersive elements to achieve outstanding throughput, sensitivity, and specificity. Because it uses a combination of reflected and thermal IR, GRIPS will detect trace gas concentrations right down to the Earth's surface. When flown in parallel to a UV/VIS sensor such as GEMS on GEO-KOMPSAT-2B over East Asia or the Sentinel 4 on MTG over Europe/Africa, the combination offers powerful finger-printing capabilities to distinguish and quantify diverse pollution sources such as electricity generation, biomass burning, and motor vehicles. From geostationary orbit, GRIPS will be able to focus on important targets to quantify sources, net flux, diurnal cycles, and long-range transport of these key components in the Earth's radiative balance and air quality.

  19. Remote Sensing of Atmospheric Climate Parameters from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Aumann, Hartmut H.; Tian, Baijun; Lee, Sung-Yung; Olsen, Ed; Lambrigtsen, Bjorn; Fetzer, Eric; Irion, F. W.; McMillan, Wallace; Strow, Larrabee; Fu, Xiouhua; Barnet, Chris; Goldberg, Mitch; Susskind, Joel; Blaisdell, John

    2006-01-01

    This paper presents the standard and research products from Atmospheric Infrared Sounder (AIRS) and their current accuracies as demonstrated through validation efforts. It also summarizes ongoing research using AIRS data for weather prediction and improving climate models.

  20. Global Daily Atmospheric State Profiles from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Chahine, Moustafa T.

    2008-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 (micro)m to 15.4 (micro)m and a 13.5 km footprint. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy on a global scale, as well as water vapor profiles, clouds, dust and trace gas amounts for CO2, CO, SO2, O3 and CH4.[1] AIRS data are used for weather forecasting and studies of global climate change. The AIRS is a 'facility' instrument developed by NASA as an experimental demonstration of advanced technology for remote sensing and the benefits of high resolution infrared spectra to science investigations.

  1. Geophysical Information from Advanced Sounder Infrared Spectral Radiance

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Zhou, Daniel K.; Liu, Xu; Smith, William L.

    2012-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Satisfying this type of improvement for inferred geophysical information from these observations requires optimal usage of data from current systems as well as enhancements to future sensors. This presentation addresses the information content present in infrared spectral radiance from advanced atmospheric sounders with an emphasis on knowledge of thermodynamic state and trace species. Results of trade-off studies conducted to evaluate the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content will be discussed. A focus is placed on information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument aboard the NPP and JPSS series of satellites which began 28 October 2011.

  2. A Simple Drought Product and Indicator Derived from Temperature and Relative Humidity Observed by the Atmospheric InfraRed Sounder (AIRS)

    NASA Astrophysics Data System (ADS)

    Granger, S. L.; Behrangi, A.

    2015-12-01

    In the United States, drought results in agricultural losses, impacts to industry, power and energy production, natural resources, municipal water supplies and human health making it one of the costliest natural hazards in the nation. Monitoring drought is therefore critical to help local governments, resource managers, and other groups make effective decisions, yet there is no single definition of drought, and because of the complex nature of drought there is no universal best drought indicator. Remote sensing applications in drought monitoring are advantageous due to the large spatial and temporal frequency of observations, leading to a better understanding of the spatial extent of drought and its duration, and in detecting the onset of drought and its intensity. NASA Earth Observing System (EOS)-era data have potential for monitoring and assessing drought and many are already used either directly or indirectly for drought monitoring. Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) observations from the Moderate Resolution Imaging Spectro-radiometer (MODIS) sensor are widely used for agricultural and environmental plant-stress monitoring via the USDM, the VegDRI project and FEWSNet. However there remain underutilized sources of information from NASA satellite observations that may have promise for characterizing and understanding meteorological drought. Once such sensor is NASA's Advanced Infra-Red Sounder (AIRS) aboard the Aqua satellite. AIRS and it's sister sensor the Advanced Microwave Sounding Unit (AMSU) that together provide meteorological information of high relevance to meteorological drought, e.g., profiles of water vapor, surface air temperature, and precipitation. Recent work undertaken to develop simple indicators of drought based on temperature and relative humidity from the AIRS suite of instruments is promising. Although there are more sophisticated indicators developed through the application of a variety of

  3. Channel alignment and radiometry in hyperspectral atmospheric infrared sounders

    NASA Technical Reports Server (NTRS)

    Elliott, Denis A.; Aumanna, H. H.; Pagano, Thomas S.; Overoye, Kenneth R.; Schindler, Rudolf A.

    2005-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyper-spectral infrared sounder which covers the 3.7 to 15,4 micron region with 2378 spectral channels. The AIRS instrument specification called for spatial co-registration of all channels to better than 2% of the field of view. Pre-launch testing confirmed that this requirement was met, since the standard deviations in the centroids was about 1% of the 13.5 km IFOV in scan and 3% in track. Detailed analysis of global AIRS data show that the typical scene gradient in 10 micron window channels is about I .3K/km rms. The way these gradients, which are predominantly caused by clouds, manifest themselves in the data depends on the details of the instrument design and the way the spectral channels are used in the data analysis, AIRS temperature and moisture retrievals use 328 of the 2378 channels from 17 independent arrays. As a result, the effect of the boresight misalignment averages to zero mean. Any increase in the effective noise is less than 0.2K. Also, there is no discernable performance degradation of products at the 45 km spatial resolution in the presence of partially cloudy scenes with up to 80% cloudiness. Single pixel radiometric differences between channels with boresight alignment differences can be appreciable and can affect scientific investigations on a single 15km footprint scale, particularly near coastlines, thunderstorms and surface emissivity inhomogeneities.

  4. Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

    PubMed

    Yu, Tianyan; Liu, Dingquan; Qin, Yang

    2014-10-01

    A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS. PMID:25322240

  5. Assimilation of thermodynamic information from advanced infrared sounders under partially cloudy skies for regional NWP

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Li, Jun; Goldberg, Mitchell D.; Schmit, Timothy J.; Lim, Agnes H. N.; Li, Zhenglong; Han, Hyojin; Li, Jinlong; Ackerman, Steve A.

    2015-06-01

    Generally, only clear-infrared spectral radiances (not affected by clouds) are assimilated in weather analysis systems. This is due to difficulties in modeling cloudy radiances as well as in observing their vertical structure from space. To take full advantage of the thermodynamic information in advanced infrared (IR) sounder observations requires assimilating radiances from cloud-contaminated regions. An optimal imager/sounder cloud-clearing technique has been developed by the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison. This technique can be used to retrieve clear column radiances through combining collocated multiband imager IR clear radiances and the sounder cloudy radiances; no background information is needed in this method. The imager/sounder cloud-clearing technique is similar to that of the microwave/IR cloud clearing in the derivation of the clear-sky equivalent radiances. However, it retains the original IR sounder resolution, which is critical for regional numerical weather prediction applications. In this study, we have investigated the assimilation of cloud-cleared IR sounder radiances using Atmospheric Infrared Sounder (AIRS)/Moderate Resolution Imaging Spectroradiometer for three hurricanes, Sandy (2012), Irene (2011), and Ike (2008). Results show that assimilating additional cloud-cleared AIRS radiances reduces the 48 and 72 h temperature forecast root-mean-square error by 0.1-0.3 K between 300 and 850 hPa. Substantial improvement in reducing track forecasts errors in the range of 10 km to 50 km was achieved.

  6. Cross-track infrared sounder FPAA performance

    NASA Astrophysics Data System (ADS)

    Masterjohn, Stacy A.; D'Souza, Arvind I.; Dawson, Larry C.; Dolan, Peter N.; Wijewarnasuriya, Priyalal S.; Ehlert, John C.

    2003-01-01

    ABSTRACT The Cross-track Infrared Sounder (CrIS) is one of many instruments that comprise the National Polar-orbiting Operational Environmental Satellite System (NPOESS). The CrIS instrument is a Michelson interferometer-based sensor that is sensitive to wavelengths between 3.5 and 16 microns. Three separate Focal Plane Array Assemblies (FPAAs) referred to as the Short Wave Infrared Assembly, the Mid Wave Infrared assembly, and the Long Wave Infrared assembly are used to span the spectral range. The CrIS instrument measures the earth radiance at high spectral resolution using the data to provide pressure, temperature and moisture profiles of the atmosphere. The CrIS instrument will help improve both global and regional predictions of weather patterns, storm tracks, and precipitation. The CrIS program selected photovoltaic (PV) detectors for use in all three spectral bands. PV technology outperforms photoconductive detectors in terms of high sensitivity and linearity. Each FPAA consists of a 3×3 detector-matrix that are used to form 9 fields of view (FOV). Each detector has a 1,000 mm active area diameter and has its own cold preamplifier, warm post amplifier and independent high pass filter. This paper describes the performance for all three assemblies that together form the basis of the CrIS Engineering Development Unit 2 (EDU2) Detector Preamp Module (DPM). Molecular Beam Epitaxy (MBE) is used to grow the appropriate bandgap n-type Hg1-xCdxTe on lattice matched CdZnTe. SWIR, MWIR and LWIR 1000 mm diameter detectors have been manufactured using the Lateral Collection Diode (LCD) architecture. Custom pre-amplifiers have been designed to interface with the large SWIR, MWIR and LWIR detectors. The operating temperature is above 78 K, permitting the use of passive radiators in spacecraft to cool the detectors. Recently, all three FPAAs were completed and tested. The tests performed on each assembly are listed.

  7. Investigations of the spatial and temporal resolution of retrievals of atmospheric carbon dioxide from the Atmospheric InfraRed Sounder (AIRS).

    NASA Astrophysics Data System (ADS)

    Maddy, Eric Sean

    As the dominant anthropogenic greenhouse gas, carbon dioxide (CO 2), represents an important component of climate change (IPCC 2007). Owing to burning of fossil fuels and deforestation, atmospheric CO2 concentrations have increased over 110 parts-per-million by volume (ppmv) from 270 ppmv to 380 ppmv since the dawn of the Industrial Revolution. Understanding of the spatial distribution of the sources and sinks of atmospheric CO 2 is necessary not only to predict the future atmospheric abundances but also their effect on future climate. Although designed for deriving high precision temperature and moisture profiles, NASA's Atmospheric InfraRed Sounder (AIRS) IR measurements include broad vertical sensitivity (between 3 and 10 km) to atmospheric CO2 variations. Coupled with AIRS' broad swath pattern and a technique referred to as "cloud-clearing" these measurements enable daily global spatial coverage. Nevertheless, AIRS' ability to determine the spatial distribution of carbon dioxide (CO2) is strongly dependent on its ability to separate the radiative effects of CO2 from temperature not to mention measurement uncertainties due to clouds and other geophysical variables such as moisture and ozone. This research presents a thorough investigation into the temporal and spatial scales that the AIRS can separate temperature (and other geophysical variables) from CO2. Through our detailed understanding of the way satellites view the Earth's atmosphere, we have developed an algorithm capable of retrieving global middle-to-upper tropospheric CO2 concentrations in all-weather conditions with total uncertainties ranging between 1 to 2 ppmv. From a radiative perspective, roughly equivalent to 30 mK to 60 mK, 1 to 2 ppmv, is an awesome feat for a space-borne sensor. Necessary for the remarkable performance of this algorithm, we developed methodologies capable of separating the radiative effect of CO2 variability from temperature, improved the fast rapid transmittance algorithm

  8. Dust aerosol optical depth and altitude retrieved from 7 years of infrared sounders observations (AIRS, IASI) and comparison with other aerosol datasets (MODIS, CALIOP, PARASOL)

    NASA Astrophysics Data System (ADS)

    Peyridieu, Sophie; Chédin, Alain; Tanré, Didier; Capelle, Virginie; Pierangelo, Clémence; Lamquin, Nicolas; Armante, Raymond

    2010-05-01

    Remote sensing of aerosol properties in the visible domain has been widely used for a better characterization of these particles and of their effect on solar radiation. On the opposite, remote sensing of aerosols in the thermal infrared domain still remains marginal. However, knowledge of the effect of aerosols on terrestrial radiation is needed for the evaluation of their total radiative forcing. A key point of infrared remote sensing is its ability to retrieve aerosol optical depth as well as mean dust layer altitude, a variable required for measuring their impact on climate. Moreover, observations are possible night and day, over ocean and over land. Our algorithm is specifically designed to retrieve simultaneously coarse mode dust aerosol 10 µm optical depth (AOD) and mean layer altitude from high spectral resolution infrared sounders observations. Thanks to IASI higher spectral resolution, the selection of finer channels for aerosol detection allows an even more accurate determination of aerosol properties. In this context, results obtained from 7 years (2003-2010) of AIRS/Aqua and more than 2 years (2007-2010) of IASI/Metop observations have been compared to other aerosol sensors. Compared to MODIS/Aqua optical depth product, 10 µm dust optical depth shows a very good agreement, particularly for tropical Atlantic regions downwind of the Sahara during the dust season. Comparisons with PARASOL non-spherical coarse mode product allows explaining small differences observed far from the sources. Time series of the mean aerosol layer altitude are compared to the CALIOP Level-2 products starting June 2006. For regions located downwind of the Sahara, the comparison again shows a good agreement with a mean standard deviation between the two products of about 400 m over the period processed, demonstrating that our algorithm effectively allows retrieving accurate mean dust layer altitude. A 7-year global climatology of the aerosol 10 µm dust optical depth and of the

  9. Cross-track infrared sounder FPAA performance

    NASA Astrophysics Data System (ADS)

    Masterjohn, Stacy A.; D'Souza, Arvind I.; Dawson, Larry C.; Dolan, Peter N.; Jefferson, Genae; Stapelbroek, Maryn G.; Willis, Richard W.; Wijewarnasuriya, Priyalal S.; Boehmer, Ellen; Ehlert, John C.; Andrews, James E.

    2005-01-01

    The Cross-track Infrared Sounder (CrIS), an interferometric sounder, is one of the instruments within the National Polar-orbiting Operational Environmental Satellite System (NPOESS) suite. CrIS measures earth radiances at high spectral resolution providing accurate and high-resolution pressure, temperature and moisture profiles of the atmosphere. These profiles are used in weather prediction models to track storms, predict levels of precipitation etc. Each CrIS instrument contains three Focal Plane Array Assemblies (FPAAs): SWIR [λc(98 K) ~ 5 mm], MWIR [λc(98 K) ~ 9 mm], and LWIR [λc(81 K) ~ 16 mm]. Each FPAA consists of nine large (850-mm-diameter) photovoltaic detectors arranged in a 3 x 3 pattern, with each detector having an accompanying cold preamplifier. This paper describes the selection methodology of the detectors that constitute the FPAAs and the performance of the CrIS SWIR, MWIR and LWIR proto-flight FPAAs. The appropriate bandgap n-type Hg1-xCdxTe was grown on lattice-matched CdZnTe. 850-mm-diameter photodiodes were manufactured using a Lateral Collection Diode (LCD) architecture. Custom pre-amplifiers were designed and built to interface with these large photodiodes. The LWIR, MWIR and SWIR detectors are operated at 81 K, 98 K and 98 K respectively. These relatively high operating temperatures permit the use of passive radiators on the instrument to cool the detectors. Performance goals are D* = 5.0 x 1010 cm-Hz1/2/W at 14.0 mm, 9.3 x 1010 cm-Hz1/2/W at 8.0 mm and 3.0 x 1011 cm-Hz1/2/W at 4.64 mm. Measured mean values for the nine photodiodes in each of the LWIR, MWIR and SWIR FPAAs are D* = 5.3 x 1010 cm-Hz1/2/W at 14.0 mm, 1.0 x 1011 cm-Hz1/2/W at 8.0 mm and 3.1 x 1011 cm-Hz1/2/W at 4.64 mm. These compare favorably with the following BLIP D* values calculated at the nominal flux condition: D* = 8.36 x 1010 cm Hz1/2/W at 14.0 mm, 1.4 x 1011 cm-Hz1/2/W at 8.0 mm and 4.1 x 1011 cm-Hz1/2/W at 4.64 mm.

  10. How Well Can Infrared Sounders Observe the Atmosphere and Surface Through Clouds?

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, L. Larrabee; Yang, Ping

    2010-01-01

    Infrared sounders, such as the Atmospheric Infrared Sounder (AIRS), the Infrared Atmospheric Sounding Interferometer (IASI), and the Cross-track Infrared sounder (CrIS), have a cloud-impenetrable disadvantage in observing the atmosphere and surface under opaque cloudy conditions. However, recent studies indicate that hyperspectral, infrared sounders have the ability to detect cloud effective-optical and microphysical properties and to penetrate optically thin clouds in observing the atmosphere and surface to a certain degree. We have developed a retrieval scheme dealing with atmospheric conditions with cloud presence. This scheme can be used to analyze the retrieval accuracy of atmospheric and surface parameters under clear and cloudy conditions. In this paper, we present the surface emissivity results derived from IASI global measurements under both clear and cloudy conditions. The accuracy of surface emissivity derived under cloudy conditions is statistically estimated in comparison with those derived under clear sky conditions. The retrieval error caused by the clouds is shown as a function of cloud optical depth, which helps us to understand how well infrared sounders can observe the atmosphere and surface through clouds.

  11. The Atmospheric Infrared Sounder Version 6 Cloud Products

    NASA Technical Reports Server (NTRS)

    Kahn, B. H.; Irion, F. W.; Dang, V. T.; Manning, E. M.; Nasiri, S. L.; Naud, C. M.; Blaisdell, J. M.; Schreier, M. M..; Yue, Q.; Bowman, K. W.; Fetzer, E. J.; Hulley, G. C.; Liou, K. N.; Lubin, D.; Ou, S. C.; Susskind, J.; Takano, Y.; Tian, B.; Worden, J. R.

    2014-01-01

    The version 6 cloud products of the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU) instrument suite are described. The cloud top temperature, pressure, and height and effective cloud fraction are now reported at the AIRS field-of-view (FOV) resolution. Significant improvements in cloud height assignment over version 5 are shown with FOV-scale comparisons to cloud vertical structure observed by the CloudSat 94 GHz radar and the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP). Cloud thermodynamic phase (ice, liquid, and unknown phase), ice cloud effective diameter D(sub e), and ice cloud optical thickness (t) are derived using an optimal estimation methodology for AIRS FOVs, and global distributions for 2007 are presented. The largest values of tau are found in the storm tracks and near convection in the tropics, while D(sub e) is largest on the equatorial side of the midlatitude storm tracks in both hemispheres, and lowest in tropical thin cirrus and the winter polar atmosphere. Over the Maritime Continent the diurnal variability of tau is significantly larger than for the total cloud fraction, ice cloud frequency, and D(sub e), and is anchored to the island archipelago morphology. Important differences are described between northern and southern hemispheric midlatitude cyclones using storm center composites. The infrared-based cloud retrievals of AIRS provide unique, decadal-scale and global observations of clouds over portions of the diurnal and annual cycles, and capture variability within the mesoscale and synoptic scales at all latitudes.

  12. The TIROS-N high resolution infrared radiation sounder

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1979-01-01

    The high-resolution infrared radiation sounder (HIRS/2) was developed and flown on the Television and Infrared Observation Satellite, N Series (TIROS-N) as one means of obtaining atmospheric vertical profile information. The HIRS/2 receives visible and infrared spectrum radiation through a single telescope and selects 20 narrow spectral channels by means of a rotating filter wheel. A passive radiant cooler provides an operating temperature of 106.7K for the HgCdTe and InSb detectors while the visible detector operates at instrument frame temperature. Low noise amplifiers and digital processing provide 13 bit data for spacecraft data multiplexing and transmission. The qualities of system performance that determine sounding capability are the dynamic range of data collection, the noise equivalent radiance of the system, the registration of the air columns sampled in each channel, and the ability to upgrade the calibration of the instrument to maintain the performance standard throughout life. The basic performance of the instrument in test is described. Early orbital information from the TIROS-N launched on October 13, 1978 are given and some observations on system quality are made.

  13. Validation of the Radiometric Stability of the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.; Elliott, D.; Strow, L. L.

    2012-01-01

    It has been widely accepted that an infrared sounder in low polar orbit is capable of producing climate quality data, if the spectral brightness temperatures have instrumental trends of less than 10 mK/yr. Achieving measurement stability at this level is not only very demanding of the design of the instrument, it is also pushes the state of art of measuring on orbit what stability is actually achieved. We discuss this using Atmospheric Infrared Sounder (AIRS) L1B data collected between 2002 and 2011. We compare the L1B brightness temperature observed in cloud filtered night tropical ocean spectra (obs) to the brightness temperature calculated based on the known surface emissivity, temperature and water vapor profiles from the ECMWF ReAnalysis (ERA) and the growth rates of CO2, N2O and Ozone. The trend in (obs-calc) is a powerful tool for the evaluation of the stability of the 2378 AIRS channels. We divided the channels into seven classes: All channels which sound in the stratosphere (at pressure levels below 150 hPa), 14 micron CO2 sounding, 4 micron CO2 P-branch sounding, 4 micron CO2 R-branch sounding, water vapor sounding, shortwave surface sounding and longwave surface sounding. The peak in the weighting function at 1050 hPa separates sounding and surface channels. The boundary between shortwave and longwave is 5 microns. Except for the stratosphere sounding channels, the remaining six groups have (obs-calc) trends of less than 20 mK/yr. The longwave surface channels have trends of 2 mK/yr, significantly less than the 8 mK/yr trend seem in the shortwave window channels. Based on the design of the instrument, trends within a group of channels should be the same. While the longwave and shortwave trends are less than the canonical 10 mK/yr, the larger trend in the shortwave channels could be an artifact of using the pre-launch determined calibration coefficients. This is currently under evaluation. The trend in (obs-calc) for the non-surface sounding channels, in

  14. Validation of the radiometric stability of the Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Aumann, H. H.; Elliott, D.; Strow, L. L.

    2012-09-01

    It has been widely accepted that an infrared sounder in low polar orbit is capable of producing climate quality data, if the spectral brightness temperatures have instrumental trends of less than 10 mK/yr. Achieving measurement stability at this level is not only very demanding of the design of the instrument, it is also pushes the state of art of measuring on orbit what stability is actually achieved. We discuss this using Atmospheric Infrared Sounder (AIRS) L1B data collected between 2002 and 2011. We compare the L1B brightness temperature observed in cloud filtered night tropical ocean spectra (obs) to the brightness temperature calculated based on the known surface emissivity, temperature and water vapor profiles from the ECMWF ReAnalysis (ERA) and the growth rates of CO2 , N2O and Ozone. The trend in (obscalc) is a powerful tool for the evaluation of the stability of the 2378 AIRS channels. We divided the channels into seven classes: All channels which sound in the stratosphere (at pressure levels below 150 hPa), 14 um CO2 sounding, 4 um CO2 P-branch sounding, 4um CO2 R-branch sounding, water vapor sounding, shortwave surface sounding and longwave surface sounding. The peak in the weighting function at 1050 hPa separates sounding and surface channels. The boundary between shortwave and longwave is 5 μm. Except for the stratosphere sounding channels, the remaining six groups have (obs-calc) trends of less than 20 mK/yr. The longwave surface channels have trends of 2 mK/yr, significantly less than the 8 mK/yr trend seem in the shortwave window channels. Based on the design of the instrument, trends within a group of channels should be the same. While the longwave and shortwave trends are less than the canonical 10 mK/yr, the larger trend in the shortwave channels could be an artifact of using the pre-launch determined calibration coefficients. This is currently under evaluation. The trend in (obs-calc) for the non-surface sounding channels, in particular for

  15. The Atmospheric Infrared Sounder on EOS

    NASA Technical Reports Server (NTRS)

    R., Aumann; Pagano, H. H.

    1993-01-01

    Recent breakthroughs in infrared detector array and cryocooler technology have made it possible to convert the concepts of optimum, passive, infrared sounding to a practical satellite-borne instrument.

  16. Small particle cirrus observed by the Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Kahn, B. H.; Eldering, A.; Fishbein, E. F.

    2003-04-01

    The high-resolution spectra of the Atmospheric Infrared Sounder (AIRS) have provided an opportunity to globally observe small particle-dominated cirrus clouds. The shape of the radiance spectra in the atmospheric windows is uniquely influenced by small ice crystals with an effective radius (reff) of a few 10s of microns and smaller. In some rare instances, minima in the AIRS brightness temperature (BT) spectra between 800 to 850 cm-1 are seen, consistent with the existence of ice particles with an reff smaller than 3 microns. Much more frequent occurences of small ice particle clouds with reff larger than 3 microns are observed through the large 998 to 811 cm-1 BT differences without minima. The small particle events are occasionally found in orographic cirrus clouds, in and around cumulonimbus towers, and in cirrus bands far removed from convection and orography. Several cases spanning the variety of small particle-dominated cirrus events will be presented. AIRS, located on the EOS-Aqua platform, is a high-resolution grating spectrometer that scans at angles 49.5 degrees on either side of nadir view, at both visible and infrared wavelengths. The surface footprint is 13.5 km at the nadir view, and coverage in the infrared is in three bandpasses (649-1136, 1265-1629, and 2169-2674 cm-1). Comparisons of observed spectra are made with simulated spectra generated by a plane-parallel scattering radiative transfer model using ice particle shapes and sizes calculated by the T-matrix method. These comparisons yield information on small particle cirrus cloud reff and optical depth. Aumann, H.H., and R.J. Pagano, Atmospheric Infrared Sounder on the Earth Observing System. Opt. Eng. 33, 776-784, 1994. Mishchenko, M.I., and L.D. Travis, Capabilities and limitations of a current Fortran implementation of the T-matrix method for randomly oriented, rotationally symmetric scatterers. J. Quant. Spectrosc. Radiat. Transfer, 60, 309-324, 1998. Moncet, J.L., and S.A. Clough

  17. Maiden flight of the infrared sounder GLORIA

    NASA Astrophysics Data System (ADS)

    Friedl-Vallon, Felix; Gloria-Team

    2013-05-01

    The Gimballed Limb Radiance Imager of the Atmosphere (GLORIA) instrument is an imaging Fourier transform spectrometer that is capable to operate on various high altitude research aircraft and on stratospheric balloons. The instrument is a joint development of the Helmholtz Centers Jülich and Karlsruhe Institute of Technology. GLORIA has flown for the first time in December 2011 on board the Russian Geophysica M55 research aircraft. Atmospheric measurements with GLORIA are possible in limb and nadir geometry. The scientific focus in limb sounding mode is on dynamics, tropopause region, TTL and polar UTLS. The nadir mode is tailored to processes in the troposphere such as biomass burning events and high precision methane measurements. The combination of limb and nadir will combine good spatial resolution in both the troposphere and lower stratosphere. In addition, GLORIA serves as a proof of concept instrument for the candidate ESA Earth explorer mission PREMIER. The GLORIA spectrometer consists of a classical Michelson interferometer combined with an infrared camera. The spectral range of the first instrument version extends from 780 cm-1 to 1400 cm-1 with a spectral resolution of up to 0.075 cm-1. The high speed HgCdTe focal plane array with 256×256 elements allows in the limb mode an extremely high spatial sampling of up to 100 m in the vertical domain. The spectrometer is mounted in a gimballed frame that permits agility in elevational and azimuthal direction, as well as image rotation. Scene acquisition and scene stabilisation are accomplished by a control system based on an inertial measurement unit. Limb scenes can be chosen within 45° and 132° to the flight direction of the aircraft allowing tomographic analysis of sampled air volumes.

  18. Calibration status of the Atmospheric Infrared Sounder after eleven years in operation

    NASA Astrophysics Data System (ADS)

    Elliott, Denis A.; Weiler, Margie; Manning, Evan M.; Pagano, Thomas S.; Broberg, Steven E.; Aumann, Hartmut H.

    2013-09-01

    The Atmospheric Infrared Sounder (AIRS) is a grating array infrared hyperspectral sounder with 2378 channels from 3.75 to 15.4 microns with spectral resolution 1200 to 1400 depending on the channel. AIRS was designed as an aid to weather prediction and for atmospheric process studies. It produces profiles of atmospheric temperature and water vapor. Because of its spectral coverage and spectral resolution it is sensitive to a number of trace atmospheric constituents including CO2, CO, SO2, O3, and CH4. The AIRS sensitivity, stability, and long life have led to its use in climate process studies and climate model validation, both of which place far more stringent requirements on calibration than weather forecasting does. This paper describes results from several special calibration sequences, originally developed for prelaunch testing, that have been used to monitor the AIRS calibration accuracy and instrument health on-orbit, including the scan mirror, space view response, and channel health. It also describes reanalyses of pre-launch calibration data used to determine calibration parameters. Finally, it shows comparisons of AIRS radiometry with two other hyperspectral infrared sounders presently in space—IASI and CrIS.

  19. Global dust infrared aerosol properties retrieved using hyperspectral sounders

    NASA Astrophysics Data System (ADS)

    Capelle, Virginie; Chédin, alain; Pondrom, Marc; Pierangelo, Clémence; Armante, Raymond; Crevoisier, Cyril; Crépeau, Laurent; Scott, Noëlle

    2015-04-01

    Observations from infrared hyperspectral sounders, here IASI and AIRS, are interpreted in terms of dust aerosol properties (AOD and mean altitude). The method is based on a "Look-Up-Table" (LUT) approach, where all radiative transfer computation is performed once for all and "off-line", for a large selection of atmospheric situations, of observing conditions, of surface characteristics (in particular the surface emissivity and temperature), and different aerosol refractive index models. The inversion scheme follows two main steps: first, determination of the observed atmospheric thermodynamic situation, second, simultaneous retrieval of the 10µm coarse-mode AOD and of the mean altitude. The method is here applied over sea and over land, at daily scale daytime and nighttime, and at the satellite pixel resolution (12 km at nadir). The geographical study area studied includes the northern tropics from west Atlantic to the Arabian peninsula and Indian ocean, and the Mediterranean basin, all of them characterized by strong, regular dust events. A special focus is given to the hourly variation of aerosol properties within a day. In this context, both IASI overpasses are processed, providing two measurements at 9:30AM and 9:30PM (equator local time) each day. First results obtained from AIRS observations, made at 1:30 AM and PM, open the way to the analysis of the aerosol diurnal cycle. For the AOD, comparisons are made with AERONET ground-based data , when available, in order to 1) evaluate our results, and 2) show the importance of a better knowledge of the aerosol diurnal cycle, especially close to the sources. Mean aerosol layer altitude obtained from IASI is compared at local scale with the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP/CALIPSO) aerosol altitude.

  20. Estimation of volcanic ash refractive index from satellite infrared sounder data

    NASA Astrophysics Data System (ADS)

    Ishimoto, H.; Masuda, K.

    2014-12-01

    The properties of volcanic ash clouds (cloud height, optical depth, and effective radius of the particles) are planned to estimate from the data of the next Japanese geostationary meteorological satellite, Himawari 8/9. The volcanic ash algorithms, such as those proposed by NOAA/NESDIS and by EUMETSAT, are based on the infrared absorption properties of the ash particles, and the refractive index of a typical volcanic rock (i.e. andesite) has been used in the forward radiative transfer calculations. Because of a variety of the absorption properties for real volcanic ash particles at infrared wavelengths (9-13 micron), a large retrieval error may occur if the refractive index of the observed ash particles was different from that assumed in the retrieval algorithm. Satellite infrared sounder provides spectral information for the volcanic ash clouds. If we can estimate the refractive index of the ash particles from the infrared sounder data, a dataset of the optical properties for similar rock type of the volcanic ash can be prepared for the ash retrieval algorithms of geostationary/polar-orbiting satellites in advance. Furthermore, the estimated refractive index can be used for a diagnostic and a correction of the ash particle model in the retrieval algorithm within a period of the volcanic activities. In this work, optimal estimation of the volcanic ash parameters was conducted through the radiative transfer calculations for the window channels of the atmospheric infrared sounder (AIRS). The estimated refractive indices are proposed for the volcanic ash particles of some eruption events.

  1. Requirements for a Moderate-Resolution Infrared Imaging Sounder (MIRIS)

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Gerber, Andrew J.; Kuai, Le; Gontijo, I.; DeLeon, Berta; Susskind, Joel; Iredell, Lena; Bajpai, Shyam

    2013-01-01

    The high cost of imaging and sounding from space warrants exploration of new methods for obtaining the required information, including changing the spectral band sets, employing new technologies and merging instruments. In some cases we must consider relaxation of the current capability. In others, we expect higher performance. In general our goal is to meet the VIIRS and CrIS requirements while providing the enhanced next generation capabilities: 1) Hyperspectral Imaging in the Vis/NIR bands, 2) High Spatial Resolution Sounding in the Infrared bands. The former will improve the accuracy of ocean color products, aerosols and water vapor, surface vegetation and geology. The latter will enable the high-impact achieved by the current suite of hyperspectral infrared sounders to be achieved by the next generation high resolution forecast models. We examine the spectral, spatial and radiometric requirements for a next generation system and technologies that can be applied from the available inventory within government and industry. A two-band grating spectrometer instrument called the Moderate-resolution Infrared Imaging Sounder (MIRIS) is conceived that, when used with the planned NASA PACE Ocean Color Instrument (OCI) will meet the vast majority of CrIS and VIIRS requirements in the all bands and provide the next generation capabilities desired. MIRIS resource requirements are modest and the Technology Readiness Level is high leading to the expectation that the cost and risk of MIRIS will be reasonable.

  2. Requirements for a Moderate-resolution Infrared Imaging Sounder (MIRIS)

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Gerber, Andrew J.; Kuai, Le; Gontijo, I.; DeLeon, Berta; Susskind, Joel; Iredell, Lena; Bajpai, Shyam

    2013-09-01

    The high cost of imaging and sounding from space warrants exploration of new methods for obtaining the required information, including changing the spectral band sets, employing new technologies and merging instruments. In some cases we must consider relaxation of the current capability. In others, we expect higher performance. In general our goal is to meet the VIIRS and CrIS requirements while providing the enhanced next generation capabilities: 1) Hyperspectral Imaging in the Vis/NIR bands, 2) High Spatial Resolution Sounding in the Infrared bands. The former will improve the accuracy of ocean color products, aerosols and water vapor, surface vegetation and geology. The latter will enable the high-impact achieved by the current suite of hyperspectral infrared sounders to be achieved by the next generation high resolution forecast models. We examine the spectral, spatial and radiometric requirements for a next generation system and technologies that can be applied from the available inventory within government and industry. A two-band grating spectrometer instrument called the Moderate-resolution Infrared Imaging Sounder (MIRIS) is conceived that, when used with the planned NASA PACE Ocean Color Instrument (OCI) will meet the vast majority of CrIS and VIIRS requirements in the all bands and provide the next generation capabilities desired. MIRIS resource requirements are modest and the Technology Readiness Level is high leading to the expectation that the cost and risk of MIRIS will be reasonable.

  3. The Atmospheric Infrared Sounder on the Earth Observing System - In-orbit spectral calibration

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.

    1991-01-01

    The Atmospheric Infrared Sounder (AIRS) is a facility instrument on the Earth Observing System (EOS). The ability of AIRS to provide accurate temperature and moisture soundings with high vertical resolution depends critically on a very accurate spectral calibration. The routine in-orbit spectral calibration is accomplished with a Fabry-Perot plate with a fixed spacing of 360 microns. This paper discusses design, Signal-to-Noise, and temperature and alignment stability constraints which have to be met to achieve the required spectral calibration accuracy.

  4. Determination of cloud parameters from infrared sounder data

    NASA Technical Reports Server (NTRS)

    Yeh, H.-Y. M.

    1984-01-01

    The World Climate Research Programme (WCRP) plan is concerned with the need to develop a uniform global cloud climatology as part of a broad research program on climate processes. The International Satellite Cloud Climatology Project (ISCCP) has been approved as the first project of the WCRP. The ISCCP has the basic objective to collect and analyze satellite radiance data to infer the global distribution of cloud radiative properties in order to improve the modeling of cloud effects on climate. Research is conducted to explore an algorithm for retrieving cloud properties by utilizing the available infrared sounder data from polar-orbiting satellites. A numerical method is developed for computing cloud top heights, amount, and emissivity on the basis of a parameterized infrared radiative transfer equation for cloudy atmospheres. Theoretical studies were carried out by considering a synthetic atmosphere.

  5. Performance status of the Atmospheric Infrared Sounder ten years after launch

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Broberg, Steve; Aumann, Hartmut H.; Elliott, Denis; Manning, Evan; Strow, Larrabee

    2012-11-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 μm to 15.4 μm and a 13.5 km footprint at nadir. The AIRS is a "facility" instrument developed by NASA as an experimental demonstration of advanced technology for remote sensing and the benefits of high resolution infrared spectra to science investigations. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy on a global scale, as well as water vapor profiles and trace gas amounts for CO2, CO, SO2, O3 and CH4. AIRS data are used for weather forecasting, climate process studies and validating climate models. The AIRS instrument has far exceeded its required design life of 5 years, with over 10 years of operations as of September 2012. While the instrument has performed exceptionally well, with little signs of wear, the AIRS Project continues to monitor and maintain the health of AIRS, characterize its behavior and improve performance where possible. Radiometric stability has been monitored and trending shows better than 16 mK/year stability. Spectral calibration stability is better than 1 ppm/year, and a new gain table was recently uploaded to recover 100 significantly degraded or dead channels by switching to their redundant counterpart. At this time we expect the AIRS to continue to perform well for the next decade.

  6. Daily global maps of carbon monoxide from NASA's Atmospheric Infrared Sounder

    NASA Astrophysics Data System (ADS)

    McMillan, W. W.; Barnet, C.; Strow, L.; Chahine, M. T.; McCourt, M. L.; Warner, J. X.; Novelli, P. C.; Korontzi, S.; Maddy, E. S.; Datta, S.

    2005-06-01

    We present the first observations of tropospheric carbon monoxide (CO) by the Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua satellite. AIRS daily coverage of ~70% of the planet represents a significant evolutionary advance in satellite trace gas remote sensing. Tropospheric CO abundances are retrieved from AIRS 4.55 μm spectral region using the full AIRS retrieval algorithm run in a research mode. The presented AIRS daily global CO maps from 22-29 September 2002 show large-scale, long-range transport of CO from anthropogenic and natural sources, most notably from biomass burning. The sequence of daily maps reveal CO advection from Brazil to the South Atlantic in qualitative agreement with previous observations. Forward trajectory analysis confirms this scenario and indicates much longer range transport into the southern Indian Ocean. Preliminary comparisons to in situ aircraft profiles indicate AIRS CO retrievals are approaching the 15% accuracy target set by pre-launch simulations.

  7. Assimilation of hyperspectral infrared sounder radiances under cloudy skies in a regional NWP model

    NASA Astrophysics Data System (ADS)

    Wang, Pei

    Satellite measurements are an important source of global observations in support of numerical weather prediction (NWP). The assimilation of satellite radiances under clear skies has greatly improved NWP forecast scores. Since most of the data assimilation models are used for the clear radiances assimilation, an important step for satellite radiances assimilation is the clear location detection. Good clear detection could effectively remove the cloud contamination and keep the clear observations for assimilation. In this dissertation, a new detection method uses collocated high spatial resolution imager data onboard the same platform as the satellite sounders to help IR sounders subpixel cloud detection, such as the Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS), the Crosstrack Infrared Sounder (CrIS) and Visible Infrared Imaging Radiometer Suite (VIIRS). The MODIS cloud mask provides a level of confidence for the observed skies to help AIRS Field-of-View (FOVs) cloud detection. By reducing the cloud contamination, a cold bias in the temperature field and a wet bias in the moisture field are corrected for the atmospheric analysis fields. These less cloud affected analysis fields further improve hurricane track and intensity forecast. The availability of satellite observations that can be assimilated in the model is limited if only the clear radiances are assimilation. An effective way to use the thermodynamic information under partially cloudy regions is to assimilate the "cloud-cleared" radiances (CCRs); CCRs are also called clear equivalent radiances. Because the CCRs are the equivalent clear radiances from the partially cloudy FOVs, they can be directly assimilated into the current data assimilation models without modifications. The AIRS CCRs are assimilated and compared with the AIRS using stand-alone cloud detection and collocated cloud detection. The assimilation of AIRS cloud-cleared radiances directly affects

  8. Three Years of Atmospheric Infrared Sounder Radiometric Calibration Validation using Sea Surface Temperatures

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.; Broberg, Steve; Elliott, Denis; Gaiser, Steve; Gregorich, Dave

    2006-01-01

    This paper evaluates the absolute accuracy and stability of the radiometric calibration of the Atmospheric Infrared Sounder (AIRS) by analyzing the difference between the brightness temperatures measured at 2616 cm(exp -1) and those calculated at the top of the atmosphere (TOA), using the Real-Time Global Sea Surface Temperature (RTGSST) for cloud-free night tropical oceans between +/- 30 degrees latitude. The TOA correction is based on radiative transfer. The analysis of the first 3 years of AIRS radiances verifies the absolute calibration at 2616 cm(exp -1) to better than 200 mK, with better than 16 mK/yr stability. The AIRS radiometric calibration uses an internal full aperture wedge blackbody with the National Institute of Standards and Technology (NIST) traceable prelaunch calibration coefficients. The calibration coefficients have been unchanged since launch. The analysis uses very tight cloud filtering, which selects about 7000 cloud-free tropical ocean spectra per day, about 0.5% of the data. The absolute accuracy and stability of the radiometry demonstrated at 2616 cm(sup -1) are direct consequences of the implementation of AIRS as a thermally controlled, cooled grating-array spectrometer and meticulous attention to details. Comparable radiometric performance is inferred from the AIRS design for all 2378 channels. AIRS performance sets the benchmark for what can be achieved with a state-of-the-art hyperspectral radiometer from polar orbit and what is expected from future hyperspectral sounders. AIRS was launched into a 705 km altitude polar orbit on NASA's Earth Observation System (EOS) Aqua spacecraft on 4 May 2002. AIRS covers the 3.7-15.4 micron region of the thermal infrared spectrum with a spectral resolution of nu/Delta nu = 1200 and has returned 3.7 million spectra of the upwelling radiance each day since the start of routine data gathering in September 2002.

  9. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  10. Application of Infrared Hyperspectral Sounder Data to Climate Research: Interannual Variability and climate trend evaluation.

    NASA Astrophysics Data System (ADS)

    Aumann, H. H.; Gregorich, D. T.

    2007-12-01

    Satellite measurements of the spectrally resolved upwelling infrared radiances have a unique role in the observation of climate and climate change: They give direct insight into the way the Earth Climate System responds to periodic and long term changes in forcing with changes in surface and atmospheric temperatures and changes in large scale atmospheric circulation patterns. The Atmospheric Infrared Sounder (AIRS), the first in a series of hyper-spectral polar orbiting sounders, was launch on the EOS Aqua into a 1:30 pm polar orbit at 705 km altitude in May 2002, with an anticipated lifetime of 12 years. The Infrared Atmospheric Sounding Interferometer (IASI) was launched in October 2006 into a 9:30 AM orbit, to be followed by the Crosstrack InfraRed Sounder (CRIS) in a 2 PM orbit in 2010. The AIRS radiometric stability since 2002 has been verified at the better than 0.01 K/year level. We report on observations of the oceans between 30S and 30N. The 0.05 K/year trend in co2 sensitive channels due to the 2 ppmv/year increase in the co2 column abundance is readily detectable and statistically reliable. The AIRS data show very consistent seasonal modulations of key surface, cloud, water vapor and atmospheric temperatures. After removing the seasonal variation, the anomaly shows interannual rms variability in the monthly means larger than 0.1 K. The rms variability in the monthly means in the mid- tropospheric temperature with peak excursions as large as 0.6 K are observed by the AIRS 2388 cm-1 channel and AMSU channel 5 at 57 GHz. The interannual variability is not obviously correlated with the Multivariate Enso Index (MEI). This variability places limits on the length of time required to measure global warming trends at the 0.1 K/decade level. These limits exceed the expected 12 year lifetime of AIRS and need to be taken into account in the design of space missions and instruments to measure climate change.

  11. Note on the Effect of Horizontal Gradients for Nadir-Viewing Microwave and Infrared Sounders

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Poli, P.

    2004-01-01

    Passive microwave and infrared nadir sounders such as the Advanced Microwave Sounding Unit A (AMSU-A) and the Atmospheric InfraRed Sounder (AIRS), both flying on NASA s EOS Aqua satellite, provide information about vertical temperature and humidity structure that is used in data assimilation systems for numerical weather prediction and climate applications. These instruments scan cross track so that at the satellite swath edges, the satellite zenith angles can reach approx. 60 deg. The emission path through the atmosphere as observed by the satellite is therefore slanted with respect to the satellite footprint s zenith. Although radiative transfer codes currently in use at operational centers use the appropriate satellite zenith angle to compute brightness temperature, the input atmospheric fields are those from the vertical profile above the center of the satellite footprint. If horizontal gradients are present in the atmospheric fields, the use of a vertical atmospheric profile may produce an error. This note attempts to quantify the effects of horizontal gradients on AIRS and AMSU-A channels by computing brightness temperatures with accurate slanted atmospheric profiles. We use slanted temperature, water vapor, and ozone fields from data assimilation systems. We compare the calculated slanted and vertical brightness temperatures with AIRS and AMSU-A observations. We show that the effects of horizontal gradients on these sounders are generally small and below instrument noise. However, there are cases where the effects are greater than the instrument noise and may produce erroneous increments in an assimilation system. The majority of the affected channels have weighting functions that peak in the upper troposphere (water vapor sensitive channels) and above (temperature sensitive channels) and are unlikely t o significantly impact tropospheric numerical weather prediction. However, the errors could be significant for other applications such as stratospheric

  12. Cloud retrieval using infrared sounder data - Error analysis

    NASA Technical Reports Server (NTRS)

    Wielicki, B. A.; Coakley, J. A., Jr.

    1981-01-01

    An error analysis is presented for cloud-top pressure and cloud-amount retrieval using infrared sounder data. Rms and bias errors are determined for instrument noise (typical of the HIRS-2 instrument on Tiros-N) and for uncertainties in the temperature profiles and water vapor profiles used to estimate clear-sky radiances. Errors are determined for a range of test cloud amounts (0.1-1.0) and cloud-top pressures (920-100 mb). Rms errors vary by an order of magnitude depending on the cloud height and cloud amount within the satellite's field of view. Large bias errors are found for low-altitude clouds. These bias errors are shown to result from physical constraints placed on retrieved cloud properties, i.e., cloud amounts between 0.0 and 1.0 and cloud-top pressures between the ground and tropopause levels. Middle-level and high-level clouds (above 3-4 km) are retrieved with low bias and rms errors.

  13. The Transition of Atmospheric Infrared Sounder Total Ozone Products to Operations

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.

    2014-01-01

    The National Aeronautics and Space Administration Short-term Prediction Research and Transition Center (NASA SPoRT) has transitioned a total column ozone product from the Atmospheric Infrared Sounder (AIRS) retrievals to the Weather Prediction Center and Ocean Prediction Center. The total column ozone product is used to diagnose regions of warm, dry, ozone-rich, stratospheric air capable of descending to the surface to create high-impact non-convective winds. Over the past year, forecasters have analyzed the Red, Green, Blue (RGB) Air Mass imagery in conjunction with the AIRS total column ozone to aid high wind forecasts. One of the limitations of the total ozone product is that it is difficult for forecasters to determine whether elevated ozone concentrations are related to stratospheric air or climatologically high values of ozone in certain regions. During the summer of 2013, SPoRT created an AIRS ozone anomaly product which calculates the percent of normal ozone based on a global stratospheric ozone mean climatology. With the knowledge that ozone values 125 percent of normal and greater typically represent stratospheric air; the anomaly product can be used with the total column ozone product to confirm regions of stratospheric air. This paper describes the generation of these products along with forecaster feedback concerning the use of the AIRS ozone products in conjunction with the RGB Air Mass product to access the utility and transition of the products.

  14. A multispectral hybrid HgCdTe FPA/dewar assembly for remote sensing in the Atmospheric Infrared Sounder (AIRS) instrument

    NASA Astrophysics Data System (ADS)

    Rutter, James H., Jr.; Jungkman, Dave; Stobie, James A.; Krueger, Eric E.; Garnett, James D.; Reine, Marion B.; Denley, Brian; Jasmin, Mark; Sofia, Anthony

    1996-10-01

    AIRS is a key instrument in NASA's Earth Observing System (EOS) Program. Passive IR remote sensing is performed using a high resolution grating spectrometer design with a wide spectral coverage focal plane assembly (FPA). The hybrid HgCdTe focal plane consists of twelve modules, ten photovoltaic (PV) and two photoconductive (PC), providing spectral response from 3.7 to 15.4 micrometers. The PV modules use silicon readout integrated circuits (ROICs) joined to the detector arrays as either direct or indirect hybrids. The PC modules are optically chopped and led out to warm electronics. Operating at 58 K, the sensitivity requirements approach BLIP in the critical 4.2 and 15.0 micrometer bands. The optical footprint coupled with the support and interface components of the focal plane make it a very large assembly, 53 mm multiplied by 66 mm. Dispersed energy from the grating is presented to the modules through 17 narrowband filters mounted 0.2 mm above the focal plane in a single, removable precision assembly. With PV and PC devices on the same focal plane operating simultaneously, shielding and lead routing as well as ROIC design have been optimized to minimize any interactions between them. Multilayer carriers have been designed to lead out the closely spaced PC arrays and the entire focal plane itself. Multilayer shielded flex cables are used to interconnect the focal plane to a very unique dewar. The tightly spaced optical pattern, along with more than 50 components in the focal plane, make this a highly complex assembly. The vacuum dewar, while providing approximately 600 leadouts, is directly coupled to the cold spectrometer and operates at 155 K while cooling the focal plane to 58 K via a sapphire rod interfaced to a pulse tube cooler. This paper discusses the key features of the FPA/dewar assembly, modeling/analyses done in support of the design, and results of design validation activities to date.

  15. Seven Years of Observations of Mid-Tropospheric CO2 from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Olsen, Edward T.

    2010-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 um spectral region with spectral resolution of better than 1200. The AIRS was designed to measure temperature and water vapor profiles and cloud properties for improvement in weather forecast and improved parameterization of climate processes. Currently the AIRS Level 1B Radiance Products are assimilated by NWP centers and have shown considerable forecast improvement. Scientists have also demonstrated accurate retrievals of minor gases from AIRS including Carbon Monoxide, Methane, and Ozone. The excellent sensitivity and stability of the AIRS instrument has recently allowed the AIRS team to successfully retrieve Carbon Dioxide (CO2) concentrations in the mid-troposphere (8-10 km) with a horizontal resolution of 100 km and accuracy of 1-2 ppm. The AIRS retrieves over 15,000 measurements per day and can achieve full global coverage in 30 days. The AIRS CO2 accuracy has been validated against a variety of aircraft measurements in the mid-troposphere and upward looking interferometers. Findings from the AIRS data include higher than expected variability in the mid-troposphere, the presence of a belt of CO2 in the southern hemisphere, and numerous observations of atmospheric circulation including the effects of El Nino/La Nina on the CO2 concentrations in the mid-troposphere. The full mid-tropospheric AIRS CO2 data set is now available at the NASA GES/DISC for almost eight years since AIRS has been operational.

  16. A global climatology of stratospheric gravity waves from Atmospheric Infrared Sounder observations

    NASA Astrophysics Data System (ADS)

    Hoffmann, Lars; Xue, Xianghui; Alexander, M. Joan

    2014-05-01

    We present the results of a new study that aims on the detection and classification of `hotspots' of stratospheric gravity waves on a global scale. The analysis is based on a nine-year record (2003 to 2011) of radiance measurements by the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. We detect the presence of stratospheric gravity waves based on 4.3 micron brightness temperature variances. Our method is optimized for peak events, i.e., strong gravity wave events for which the local variance considerably exceeds background levels. We estimated the occurrence frequencies of these peak events for different seasons and time of day and used the results to find local maxima of gravity wave activity. In addition, we use AIRS radiances at 8.1 micron to simultaneously detect convective events, including deep convection in the tropics and mesoscale convective systems at mid latitudes. We classified the gravity waves according to their sources, based on seasonal occurrence frequencies for convection and by means of topographic data. Our study reproduces well-known hotspots of gravity waves, e.g., the mountain wave hotspots at the Andes and the Antarctic Peninsula or the convective hotspot during the thunderstorm season over the North American Great Plains. However, the high horizontal resolution of the AIRS observations also helped us to locate several smaller hotspots, which were partly unknown or poorly studied so far. Most of these smaller hotspots are found near orographic features like small mountain ranges, in coastal regions, in desert areas, or near isolated islands. This new study will help to select the most promising regions and seasons for future observational studies of gravity waves. Reference: Hoffmann, L., X. Xue, and M. J. Alexander, A global view of stratospheric gravity wave hotspots located with Atmospheric Infrared Sounder observations, J. Geophys. Res., 118, 416-434, doi:10.1029/2012JD018658, 2013.

  17. Preface to Special Section: Validation of Atmospheric Infrared Sounder Observations

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.

    2006-01-01

    The papers described below demonstrate that the AIRS calibrated radiances and retrieved geophysical products generally meet or exceed the prelaunch specifications. The retrieved quantities show little variation in uncertainty as a function of cloud amount. However, AIRS retrieval yield is a rapidly decreasing function of cloud amount; at about 80% cloudiness essentially no infrared radiances are used in the retrieval processes. Also, AIRS performance has not been demonstrated for all conditions and products. Calibrated and forward calculated radiances meet performance specifications for conditions varying from the cold poles to warm tropics. The retrieval system performs well over extrapolar land in the free troposphere (2-15 km above the surface) and over extrapolar oceans at all tropospheric altitudes. The AIRS retrieval algorithms have not been optimized for polar winter conditions, so no such results are presented in these papers.

  18. Monthly Representations of Mid-Tropospheric Carbon Dioxide from the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Olsen, Edward T.; Chahine, Moustafa T.; Ruzmaikin, Alexander; Nguyen, Hai; Jiang, Xun

    2011-01-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Earth Observing System Aqua spacecraft was launched in May of 2002 and acquires hyperspectral infrared spectra used to generate a wide range of atmospheric products including temperature, water vapor, and trace gas species including carbon dioxide. Here we present monthly representations of global concentrations of mid-tropospheric carbon dioxide produced from 8 years of data obtained by AIRS between the years of 2003 and 2010. We define them as "representations" rather than "climatologies" to reflect that the files are produced over a relatively short time period and represent summaries of the Level 3 data. Finally, they have not yet been independently validated. The representations have a horizontal resolution of 2.0 deg x 2.5 deg (Latitude x Longitude) and faithfully reproduce the original 8 years of monthly L3 CO2 concentrations with a standard deviation of 1.48 ppm and less than 2% outliers. The representations are intended for use in studies of the global general circulation of CO2 and identification of anomalies in CO2 typically associated with atmospheric transport. The seasonal variability and trend found in the AIRS CO2 data are discussed.

  19. Value-added Impact from Future Geostationary Hyperspectral Infrared Sounder Observations on Hurricane Forecasts

    NASA Astrophysics Data System (ADS)

    Li, J.; Schmit, T. J.; Li, Z.; Zhu, F.; Lim, A.; Atlas, R. M.; John, P.

    2015-12-01

    Future geostationary (Geo) advanced InfraRed (IR) sounders have finer spatial, spectral, and temporal resolutions compared with the existing GOES sounders, providing much improved resolving power of atmospheric thermodynamic information. When quantitatively assessing the value-added impact from such instruments over the current sounding systems onboard the Low Earth Orbit (Leo) satellites, the real question is what is the optimal impact using the current assimilation/forecast systems. More specifically, will assimilation of more observations from Geo IR sounders with the current assimilation/forecast systems yield improved forecast as expected? And if so, how to assimilate the high temporal resolution Geo sounding information and what is the impact on forecasts? Taken tropical cyclone (TC) forecasting as an example, this study tries to address these questions through a quick regional Observing System Simulation Experiments (r-OSSE) study. The synthetic observations are simulated from the sample ECMWF T1279 nature run (NR) for Hurricane Sandy (2012), including RAOB, the Leo AIRS, and Geo AIRS. Various experiments were carried out using WRF 3.6.1 and GSI 3.3 to study the impact on Sandy track forecast. And the study shows that a) it is critical to assign an appropriate observational error (observation error covariance matrix - O matrix) in order to show improved positive impacts from Geo AIRS over Leo AIRS; b) cycling of 3/6-hourly shows improved positive impacts over none cycling, but hourly cycling does not show further improvement on forecasts among all experiments, and c) with thinning (120 ~ 240 km), the impacts have the following order: hourly > 3-hourly > 6-hourly > none cycling. These experiments indicate that while more observations may improve forecasts, much more observations are difficult to show further improvement with the current assimilation/forecast system configurations. There exists a tradeoff between the number of observations to be assimilated

  20. The spaceborne infrared atmospheric sounder for geosynchronous earth orbit (SIRAS-G): pathfinder to space

    NASA Astrophysics Data System (ADS)

    Kampe, Thomas U.; Chase, Holden

    2007-09-01

    The Spaceborne Infrared Sounder for Geosynchronous Earth Orbit (SIRAS-G) was developed by Ball Aerospace and Technologies Corp (BATC) under NASA's 2002 Instrument Incubator Program. SIRAS-G is a technology development program focused on next-generation IR imaging spectrometers for sounding of the atmosphere. SIRAS-G is ideally suited for measuring atmospheric temperature and water vapor profiles, trace gases concentrations, land and ocean surface temperatures and the IR mineral dust aerosol signature from satellite, providing high-spectral resolution imaging spectroscopy over a broad IR spectral range and extended field of view. Instrument concepts for future mission in LEO and GEO are discussed, including an instrument concept to be flown in low earth orbit having the potential to provide high spatial resolution, comparable to that of MODIS, along with the high spectral resolution currently being demonstrated by the Atmospheric Infrared Sounder (AIRS). This capability would dramatically improve the yield of cloud-free pixels scenes that can be assimilated into Numerical Weather Prediction (NWP) models. The SIRAS-G dispersive spectrometer module is readily adaptable for missions in LEO, GEO and MEO orbits and can be optimized for spectral resolution over subsets of the total spectral range. We have completed the 3-year SIRAS-G IIP development effort, including successful testing of the SIRAS-G laboratory demonstration spectrometer that utilized the Hawaii 1RG MWIR FPA. Performance testing was conducted at cryogenic temperatures and the performance of the demo instrument has been quantified including measurement of keystone distortion, spectral smile, MTF, and the spectral response function (SRF) to high accuracy. We present the results of the laboratory instrument development including characterization of the demonstration instrument performance. We discuss instrument concepts utilizing SIRAS-G technology for potential future missions including an anticipated

  1. Analysis of SO II point source emissions using NASA atmospheric infrared sounder data

    NASA Astrophysics Data System (ADS)

    Shen, Sylvia S.; Miller, David P.; Lewis, Paul E.

    2007-04-01

    Determining the extent to which large power plant emission sources interacting with atmospheric constituents affect the environment could play a significant role in future U.S. energy production policy. The effects on the environment caused by the interaction between power plant emissions and atmospheric constituents has not been investigated in depth due to the lack of calibrated spectral data on a suitable temporal and spatial scale. The availability of NASA's space-based Atmospheric Infrared Sounder (AIRS) data makes it possible to explore, and begin the first steps toward establishing, a correlation between known emission sources and environmental indicators. An exploratory study was conducted in which a time series of 26 cloud-free AIRS data containing two coal-fired power plants in northern New Mexico were selected, acquired, and analyzed for SO II emissions. A generic forward modeling process was also developed to derive an estimate of the expected AIRS pixel radiance containing the SO II emissions from the two power plants based on published combustion analysis data for coal and available power plant documentation. Analysis of the AIRS NEΔR calculated in this study and subsequent comparison with the radiance values for SO II calculated from the forward model provided essential information regarding the suitability and risk in the use of a modified AIRS configuration for monitoring anthropogenic point source emissions. The results of this study along with its conclusions and recommendations in conjunction with additional research collaboration in several specific topics will provide guidance for the development of the next generation infrared spectrometer system that NASA is considering building for environmental monitoring.

  2. Detection of Ice Polar Stratospheric Clouds from Assimilation of Atmospheric Infrared Sounder Data

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Benson, Craig; Liu, Hui-Chun; Pawson, Steven; Chang, Ping; Riishojgaard, Lars Peter

    2006-01-01

    A novel technique is presented for detection of ice polar stratospheric clouds (PSCs) that form at extremely low temperatures in the lower polar stratosphere during winter. Temperature is a major factor in determining abundance of PSCs, which in turn provide surfaces for heterogeneous chemical reactions leading to ozone loss and radiative cooling. The technique infers the presence of ice PSCs using radiances from the Atmospheric Infrared Sounder (AIRS) in the Goddard Earth Observing System version 5 (GEOS-5) data assimilation system. Brightness temperatures are computed from short-term GEOS-5 forecasts for several hundred AIRS channels, using a radiation transfer module. The differences between collocated AIRS observations and these computed values are the observed-minus-forecast (O-F) residuals in the assimilation system. Because the radiation model assumes clear-sky conditions, we hypothesize that these O-F residuals contain quantitative information about PSCs. This is confirmed using sparse data from the Polar Ozone and Aerosol Measurement (POAM) III occultation instrument. The analysis focuses on 0-F residuals for the 6.79pm AIRS moisture channel. At coincident locations, when POAM III detects ice clouds, the AIRS O-F residuals for this channel are lower than -2K. When no ice PSCs are evident in POAM III data, the AIRS 0-F residuals are larger. Given this relationship, the high spatial density of AIRS data is used to construct maps of regions where 0-F residuals are lower than -2K, as a proxy for ice PSCs. The spatial scales and spatio-temporal variations of these PSCs in the Antarctic and Arctic are discussed on the basis of these maps.

  3. The Radiative Consistency of Atmospheric Infrared Sounder and Moderate Resolution Imaging Spectroradiometer Cloud Retrievals

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Fishbein, Evan; Nasiri, Shaima L.; Eldering, Annmarie; Fetzer, Eric J.; Garay, Michael J.; Lee, Sung-Yung

    2007-01-01

    The consistency of cloud top temperature (Tc) and effective cloud fraction (f) retrieved by the Atmospheric Infrared Sounder (AIRS)/Advanced Microwave Sounding Unit (AMSU) observation suite and the Moderate Resolution Imaging Spectroradiometer (MODIS) on the EOS-Aqua platform are investigated. Collocated AIRS and MODIS TC and f are compared via an 'effective scene brightness temperature' (Tb,e). Tb,e is calculated with partial field of view (FOV) contributions from TC and surface temperature (TS), weighted by f and 1-f, respectively. AIRS reports up to two cloud layers while MODIS reports up to one. However, MODIS reports TC, TS, and f at a higher spatial resolution than AIRS. As a result, pixel-scale comparisons of TC and f are difficult to interpret, demonstrating the need for alternatives such as Tb,e. AIRS-MODIS Tb,e differences ((Delta)Tb,e) for identical observing scenes are useful as a diagnostic for cloud quantity comparisons. The smallest values of DTb,e are for high and opaque clouds, with increasing scatter in (Delta)Tb,e for clouds of smaller opacity and lower altitude. A persistent positive bias in DTb,e is observed in warmer and low-latitude scenes, characterized by a mixture of MODIS CO2 slicing and 11-mm window retrievals. These scenes contain heterogeneous cloud cover, including mixtures of multilayered cloudiness and misplaced MODIS cloud top pressure. The spatial patterns of (Delta)Tb,e are systematic and do not correlate well with collocated AIRS-MODIS radiance differences, which are more random in nature and smaller in magnitude than (Delta)Tb,e. This suggests that the observed inconsistencies in AIRS and MODIS cloud fields are dominated by retrieval algorithm differences, instead of differences in the observed radiances. The results presented here have implications for the validation of cloudy satellite retrieval algorithms, and use of cloud products in quantitative analyses.

  4. High Resolution Infrared Radiation Sounder (HIRS) for the Nimbus F Spacecraft

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1975-01-01

    Flown on Nimbus F in June 1975, the high resolution infrared radiation sounder (HIRS) scans with a geographical resolution of 23KM and samples radiance in seventeen selected spectral channels from visible (.7 micron) to far IR (15 micron). Vertical temperature profiles and atmospheric moisture content can be inferred from the output. System operation and test results are described.

  5. Performance of the HIRS/2 instrument on TIROS-N. [High Resolution Infrared Radiation Sounder

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1980-01-01

    The High Resolution Infrared Radiation Sounder (HIRS/2) was developed and flown on the TIROS-N satellite as one means of obtaining atmospheric vertical profile information. The HIRS/2 receives visible and infrared spectrum radiation through a single telescope and selects 20 narrow radiation channels by means of a rotating filter wheel. A passive radiant cooler provides an operating temperature of 106.7 K for the HgCdTe and InSb detectors while the visible detector operates at instrument frame temperature. Low noise amplifiers and digital processing provide 13 bit data for spacecraft data multiplexing and transmission. The qualities of system performance that determine sounding capability are the dynamic range of data collection, the noise equivalent radiance of the system, the registration of the air columns sampled in each channel and the ability to upgrade the calibration of the instrument to maintain the performance standard throughout life. The basic features, operating characteristics and performance of the instrument in test are described. Early orbital information from the TIROS-N launched on October 13, 1978 is given and some observations on system quality are made.

  6. Trade-off studies of a hyperspectral infrared sounder on a geostationary satellite.

    PubMed

    Wang, Fang; Li, Jun; Schmit, Timothy J; Ackerman, Steven A

    2007-01-10

    Trade-off studies on spectral coverage, signal-to-noise ratio (SNR), and spectral resolution for a hyperspectral infrared (IR) sounder on a geostationary satellite are summarized. The data density method is applied for the vertical resolution analysis, and the rms error between true and retrieved profiles is used to represent the retrieval accuracy. The effects of spectral coverage, SNR, and spectral resolution on vertical resolution and retrieval accuracy are investigated. The advantages of IR and microwave sounder synergy are also demonstrated. When focusing on instrument performance and data processing, the results from this study show that the preferred spectral coverage combines long-wave infrared (LWIR) with the shorter middle-wave IR (SMidW). Using the appropriate spectral coverage, a hyperspectral IR sounder with appropriate SNR can achieve the required science performance (1 km vertical resolution, 1 K temperature, and 10% relative humidity retrieval accuracy). The synergy of microwave and IR sounders can improve the vertical resolution and retrieval accuracy compared to either instrument alone. PMID:17268565

  7. Nighttime Cirrus Detection using Atmospheric Infrared Sounder Window Channels and Total Column Water Vapor

    NASA Technical Reports Server (NTRS)

    Kahn, Brian H.; Liou, Kuo Nan; Lee, Sung-Yung; Fishbein, Evan F.; DeSouza-Machado, Sergio; Eldering, Annmarie; Fetzer, Eric J.; Hannon, Scott E.; Strow, L. Larrabee

    2005-01-01

    A method of cirrus detection at nighttime is presented that utilizes 3.8 and 10.4 (micro)m infrared (IR) window brightness temperature differences (dBT) and total column precipitable water (PW) measurements. This technique is applied to the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit A (AMSU-A) instrument suite on board EOS-Aqua, where dBT is determined from sets of carefully selected AIRS window channels, while PW is derived from the synergistic AIRS and AMSU-A water vapor retrievals. Simulated and observed dBT for a particular value of PW are not constant; several physical factors impact dBT, including the variability in temperature and relative humidity profiles, surface emissivity, instrument noise, and skin/ near-surface air temperature differences. We simulate clear-sky dBT over a realistic range of PWs using 8350 radiosondes that have varying temperature and relative humidity profiles. Thresholds between cloudy and uncertain sky conditions are derived once the scatter in the clear-sky dBT is determined. Simulations of optically thin cirrus indicate that this technique is most sensitive to cirrus optical depth in the 10 (micro)m window of 0.1-0.15 or greater over the tropical and subtropical oceans, where surface emissivity and skin/near-surface air temperature impacts on the IR radiances are minimal. The method at present is generally valid over oceanic regions only, specifically, the tropics and subtropics. The detection of thin cirrus, and other cloud types, is validated using observations at the Atmospheric Radiation Measurement (ARM) program site located at Manus Island in the tropical western Pacific for 89 coincident EOS-Aqua overpasses. Even though the emphasis of this work is on the detection of thin cirrus at nighttime, this technique is sensitive to a broad cloud morphology. The cloud detection technique agrees with ARM-detected clouds 82-84% of the time, which include thin cirrus, as well as other cloud types. Most of

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  9. Field Tests of a Gas-Filter Imaging Radiometer for Methane, CH4,: A Prototype for Geostationary Remote Infrared Pollution Sounder, GRIPS

    NASA Astrophysics Data System (ADS)

    Dickerson, R. R.; Fish, C. S.; Brent, L. C.; Burrows, J. P.; Fuentes, J. D.; Gordley, L. L.; Jacob, D. J.; Schoeberl, M. R.; Salawitch, R. J.; Ren, X.; Thompson, A. M.

    2013-12-01

    Gas filter radiometry is a powerful tool for measuring infrared active trace gases. Methane (CH4) is the second most important greenhouse gas and is more potent molecule for molecule than carbon dioxide (CO2). Unconventional natural gas recovery has the potential to show great environmental benefits relative to coal, but only if fugitive leakage is held below 3% and leak rates remain highly uncertain. We present design specifications and initial field/aircraft test results for an imaging remote sensing device to measure column content of methane. The instrument is compared to in situ altitude profiles measured with cavity ring-down. This device is an airborne prototype for the Geostationary Remote Infrared Pollution Sounder, GRIPS, a satellite instrument designed to monitor CH4, CO2, CO, N2O and AOD from geostationary orbit, with capabilities for great advances in air quality and climate research. GRIPS: The Geostationary Remote Infrared Pollution Sounder

  10. HIRS-AMTS satellite sounding system test - Theoretical and empirical vertical resolving power. [High resolution Infrared Radiation Sounder - Advanced Moisture and Temperature Sounder

    NASA Technical Reports Server (NTRS)

    Thompson, O. E.

    1982-01-01

    The present investigation is concerned with the vertical resolving power of satellite-borne temperature sounding instruments. Information is presented on the capabilities of the High Resolution Infrared Radiation Sounder (HIRS) and a proposed sounding instrument called the Advanced Moisture and Temperature Sounder (AMTS). Two quite different methods for assessing the vertical resolving power of satellite sounders are discussed. The first is the theoretical method of Conrath (1972) which was patterned after the work of Backus and Gilbert (1968) The Backus-Gilbert-Conrath (BGC) approach includes a formalism for deriving a retrieval algorithm for optimizing the vertical resolving power. However, a retrieval algorithm constructed in the BGC optimal fashion is not necessarily optimal as far as actual temperature retrievals are concerned. Thus, an independent criterion for vertical resolving power is discussed. The criterion is based on actual retrievals of signal structure in the temperature field.

  11. Lessons from 18 Years of Hyperspectral Infrared Sounder Data

    NASA Technical Reports Server (NTRS)

    Aumann, H. H.; Manning, E. M.; Strow, L. L.

    2013-01-01

    By the end of 2013 NASA and EUMETSAT will have accumulated more than 11 years of AIRS, 6 years of IASI and one year of CrIS data. All three instruments were nominally specified to support the NWC for short term weather forecasting with a five year lifetime, but continue to exceed the accuracy requirement needed for weather forecasting alone. This allows use of their data for a much broader range of applications, including the calibration of broad-band instruments in space and climate research. We illustrate calibration aspects with examples from AIRS, IASI and CrIS using spatially uniform clear conditions, simultaneous nadir overpasses and random nadir samples. The differences between AIRS, IASI and CrIS for the purpose of weather forecasting are small and we expect that the excellent forecast impact demonstrated by the combination of AIRS and IASI will be continued by the combination of CrIS and IASI. Clear data are useful for calibration, but contain no climate signal. The analysis of random nadir samples from AIRS and CrIS identifies larger biases for observation of extreme conditions, represented by 1% and 99%tile data than for non-extreme observations. This is relevant for climate analysis. Resolution of these differences require further work, since they can complicate the continuation of trends established by AIRS with CrIS data, at least for extrema. The unequaled stability of the AIRS data allows us to evaluate trends using random nadir sampled data. We see an increasing frequency in severe storms over land, a decreasing frequency over ocean. The 11 years of AIRS data are too short to tell if these trends are significant from a climate change viewpoint, or if they are parts of multi-decadal oscillations.

  12. Case study of the March 24, 1976 Elton, Louisiana tornado using satellite infrared imagery, Doppler sounder, rawinsonde, and radar observations

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Smith, R. E.

    1983-01-01

    The Elton, Louisiana tornado on March 24, 1976 has been studied using GOES digital infrared data for the growth and collapse of the cloud top, the temperature-height relationship and air mass instability from rawinsonde data, gravity waves from Doppler sounder records, and radar summaries from storm activity during the three-hour time period immediately preceding the touchdown of the tornado. In this case, the overshooting turret collapsed 30 minutes before the tornado touchdown as the eastward moving cloud reached Elton, Louisiana. Results show that the gravity waves were excited by the enhanced convection of the storm penetrating through the tropopause in the 2.5 hour time period before the tornado touched down.

  13. Thermal Band Atmospheric Correction Using Atmospheric Profiles Derived from Global Positioning System Radio Occultation and the Atmospheric Infrared Sounder

    NASA Technical Reports Server (NTRS)

    Pagnutti, Mary; Holekamp, Kara; Stewart, Randy; Vaughan, Ronald D.

    2006-01-01

    This Rapid Prototyping Capability study explores the potential to use atmospheric profiles derived from GPS (Global Positioning System) radio occultation measurements and by AIRS (Atmospheric Infrared Sounder) onboard the Aqua satellite to improve surface temperature retrieval from remotely sensed thermal imagery. This study demonstrates an example of a cross-cutting decision support technology whereby NASA data or models are shown to improve a wide number of observation systems or models. The ability to use one data source to improve others will be critical to the GEOSS (Global Earth Observation System of Systems) where a large number of potentially useful systems will require auxiliary datasets as input for decision support. Atmospheric correction of thermal imagery decouples TOA radiance and separates surface emission from atmospheric emission and absorption. Surface temperature can then be estimated from the surface emission with knowledge of its emissivity. Traditionally, radiosonde sounders or atmospheric models based on radiosonde sounders, such as the NOAA (National Oceanic & Atmospheric Administration) ARL (Air Resources Laboratory) READY (Real-time Environmental Application and Display sYstem), provide the atmospheric profiles required to perform atmospheric correction. Unfortunately, these types of data are too spatially sparse and too infrequently taken. The advent of high accuracy, global coverage, atmospheric data using GPS radio occultation and AIRS may provide a new avenue for filling data input gaps. In this study, AIRS and GPS radio occultation derived atmospheric profiles from the German Aerospace Center CHAMP (CHAllenging Minisatellite Payload), the Argentinean Commission on Space Activities SAC-C (Satellite de Aplicaciones Cientificas-C), and the pair of NASA GRACE (Gravity Recovery and Climate Experiment) satellites are used as input data in atmospheric radiative transport modeling based on the MODTRAN (MODerate resolution atmospheric

  14. Temporal and zonal variability and of mid-tropospheric carbon dioxide from the Atmospheric Infrared Sounder compared to surface measurements

    NASA Astrophysics Data System (ADS)

    Pagano, T. S.; Olsen, E. T.; Nguyen, H. M.; Jiang, X.

    2012-12-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in the 3.7-15.4 um spectral region with spectral resolution of better than 1200, and spatial resolution of 13.5 km with global daily coverage. The AIRS was designed to measure temperature and water vapor profiles for improvement in weather forecast and improved parameterization of climate processes. Currently the AIRS Level 1B Radiance Products are assimilated by NWP centers worldwide and have shown considerable forecast improvement. AIRS L1 and L2 products are widely used for studying critical climate processes related to water vapor feedback, atmospheric transport and cloud properties. AIRS trace gas products include ozone profiles, carbon monoxide, and the first global maps of mid-tropospheric carbon dioxide. The global daily coverage of AIRS allows scientists to follow the transport of these gases to aid in validation of chemical/weather transport models. AIRS mid-tropospheric carbon dioxide has a peak sensitivity of about 450 mb and a width of about 500 mb. This broad mid-tropospheric sensitivity is useful for identifying global circulation patterns including ENSO (Jiang et al., 2010) and MJO (Li et al., 2010). Climatologies were developed that represent averages of AIRS Monthly L3 CO2 data detrended and averaged over the individual months for 12 maps on 2.0 x 2.5 degree grid scale (Pagano, 2011). The climatologies show a persistent low in the CO2 in the South Atlantic due to a constant downward flux from the Walker Circulation. The significantly reduced noise level in the climatologies also reveal that the horizontal variability in the AIRS CO2 measurements is not entirely driven by global circulation, but also the underlying global vegetation cycle. Further investigation into the seasonal behavior of the zonal averages of AIRS CO2, AIRS mid-troposphere and surface temperature data, MODIS derived GPP, and other ground

  15. NPOESS Preparatory Project Validation Program for the Cross-track Infrared Sounder

    NASA Astrophysics Data System (ADS)

    Barnet, C.; Gu, D.; Nalli, N. R.

    2009-12-01

    The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Program, in partnership with National Aeronautical Space Administration (NASA), will launch the NPOESS Preparatory Project (NPP), a risk reduction and data continuity mission, prior to the first operational NPOESS launch. The NPOESS Program, in partnership with Northrop Grumman Aerospace Systems, will execute the NPP Calibration and Validation (Cal/Val) program to ensure the data products comply with the requirements of the sponsoring agencies. The Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) are two of the instruments that make up the suite of sensors on NPP. Together, CrIS and ATMS will produce three Environmental Data Records (EDRs) including the Atmospheric Vertical Temperature Profile (AVTP), Atmospheric Vertical Moisture Profile (AVMP), and the Atmospheric Vertical Pressure Profile (AVPP). The AVTP and the AVMP are both NPOESS Key Performance Parameters (KPPs). The validation plans establish science and user community leadership and participation, and demonstrated, cost-effective Cal/Val approaches. This presentation will provide an overview of the collaborative data, techniques, and schedule for the validation of the NPP CrIS and ATMS environmental data products.

  16. Space-borne observation of methane from atmospheric infrared sounder version 6: validation and implications for data analysis

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Weng, F.; Liu, Q.; Olsen, E.

    2015-08-01

    Atmospheric Methane (CH4) is generated as a standard product in recent version of the hyperspectral Atmospheric Infrared Sounder (AIRS-V6) aboard NASA's Aqua satellite at the NASA Goddard Earth Sciences Data and Information Services Center (NASA/GES/DISC). Significant improvements in AIRS-V6 was expected but without a thorough validation. This paper first introduced the improvements of CH4 retrieval in AIRS-V6 and some characterizations, then presented the results of validation using ~ 1000 aircraft profiles from several campaigns spread over a couple of years and in different regions. It was found the mean biases of AIRS CH4 at layers 343-441 and 441-575 hPa are -0.76 and -0.05 % and the RMS errors are 1.56 and 1.16 %, respectively. Further analysis demonstrates that the errors in the spring and in the high northern latitudes are larger than in other seasons or regions. The error is correlated with Degree of Freedoms (DOFs), particularly in the tropics or in the summer, and cloud amount, suggesting that the "observed" spatiotemporal variation of CH4 by AIRS is imbedded with some artificial impact from the retrieval sensitivity in addition to its variation in reality, so the variation of information content in the retrievals needs to be taken into account in data analysis of the retrieval products. Some additional filtering (i.e. rejection of profiles with obvious oscillation as well as those deviating greatly from the norm) for quality control is recommended for the users to better utilize AIRS-V6 CH4, and their implementation in the future versions of the AIRS retrieval algorithm is under consideration.

  17. A Network of Direct Broadcast Antenna Systems to Provide Real-Time Infrared and Microwave Sounder Data for Numerical Weather Prediction

    NASA Astrophysics Data System (ADS)

    Gumley, L.

    2013-12-01

    The Space Science and Engineering Center at the University of Wisconsin-Madison is creating a network of direct broadcast satellite data reception stations to acquire and process infrared and microwave sounder data in real-time from polar orbiting meteorological satellites and deliver the resulting products to NOAA with low latency for assimilation in NCEP numerical weather prediction models. The network will include 4 antenna sites that will be operated directly by SSEC, including Madison WI, Honolulu HI, Miami FL, and Mayaguez PR. The network will also include partner antenna sites not directly controlled by SSEC, including Corvallis OR, Monterey CA, Suitland MD, Fairbanks AK, and Guam. All of the antenna sites will have a combined X/L-band reception system capable of receiving data via direct broadcast from polar orbiting satellites including Suomi NPP and JPSS-1, Metop-A/B, POES,Terra, and Aqua. Each site will collect raw data from these satellites locally, process it to Level 1 (SDR) and Level 2 (EDR) products, and transmit the products back to SSEC for delivery to NOAA/NCEP. The primary purpose of the antenna systems is to provide real-time infrared and microwave sounder data from Metop and Suomi-NPP to NOAA to support data assimilation for NOAA/NCEP operational numerical weather prediction models. At present, NOAA/NCEP use of advanced infrared (CrIS, IASI, AIRS) and microwave (ATMS, AMSU) sounder data over North America in NWP data assimilation is limited because of the latency of the products in relation to the cutoff times for assimilation runs. This network will deliver infrared and microwave sounder data to NCEP with the lowest latency possible, via the reception and processing of data received via direct broadcast. CIMSS/SSEC is managing the procurement and installation of the antenna systems at the two new sites, and will operate the stations remotely. NOAA will establish the reception priorities (Metop and SNPP will be at the highest priority) and

  18. Suomi NPP/JPSS Cross-track Infrared Sounder (CrIS): Calibration Validation With The Aircraft Based Scanning High-resolution Interferometer Sounder (S-HIS)

    NASA Astrophysics Data System (ADS)

    Taylor, J. K.; Revercomb, H. E.; Tobin, D.; Knuteson, R. O.; Best, F. A.; Adler, D. A.; Pettersen, C.; Garcia, R. K.; Gero, P.

    2013-12-01

    To better accommodate climate change monitoring and improved weather forecasting, there is an established need for higher accuracy and more refined error characterization of radiance measurements from space and the corresponding geophysical products. This need has led to emphasizing direct tests of on-orbit performance, referred to as validation. Currently, validation typically involves (1) collecting high quality reference data from airborne and/or ground-based instruments during the satellite overpass, and (2) a detailed comparison between the satellite-based radiance measurements and the corresponding high quality reference data. Additionally, for future missions technology advancements at the University of Wisconsin Space Science and Engineering Center (UW-SSEC) have led to the development of an on-orbit absolute radiance reference utilizing miniature phase change cells to provide direct on-orbit traceability to International Standards (SI). The detailed comparison between the satellite-based radiance measurements and the corresponding measurements made from a high-altitude aircraft must account for instrument noise and scene variations, as well as differences in instrument observation altitudes, view angles, spatial footprints, and spectral response. Most importantly, for the calibration validation process to be both accurate and repeatable the reference data instrument must be extremely well characterized and understood, carefully maintained, and accurately calibrated, with traceability to absolute standards. The Scanning High-resolution Interferometer Sounder (S-HIS) meets and exceeds these requirements and has proven to do so on multiple airborne platforms, each with significantly different instrument operating environments. The Cross-track Infrared Sounder (CrIS) on Suomi NPP, launched 28 October 2011, is designed to give scientists more refined information about Earth's atmosphere and improve weather forecasts and our understanding of climate. CrIS is an

  19. Atmospheric measurements of volcanic eruptions with the infrared sounder IASI (Arne Richter Award for Outstanding Young Scientists Lecture)

    NASA Astrophysics Data System (ADS)

    Clarisse, L.

    2012-04-01

    Due to their spatial coverage, satellite sounders are ideal for measuring volcanic emissions. They are able to monitor (dormant) volcanoes in remote parts of the world and measure large plumes from explosive eruptions. Currently over a dozen instruments (operating in the IR and UV spectral ranges) are capable of detecting volcanic ash and/or sulphur dioxide. Satellite measurements are highly relevant for hazard mitigation, locally but also on large scales for air traffic avoidance of volcanic clouds. Their coverage enables to establish an accurate time-record of global volcanic emissions. This is useful from a volcanology perspective, but also for assessing the global climate impact of volcanic emissions. In this talk we give an overview of four years of measurements of large eruptive plumes from the high resolution infrared atmospheric sounding interferometer (IASI). The focus is on the detection and measurement of volcanic aerosol (volcanic ash, ice and sulphuric acid). In the second part of this talk, we discuss sulphur dioxide measurements and the recent first observations of hydrogen sulphide. We conclude with a discussion of open problems and challenges which lie ahead for the remote sensing of volcanic products.

  20. AIRS Infrared Polarization Sensitivity and In-Flight Observations

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Elliott, Denis; Broberg, Steven E.

    2005-01-01

    The Atmospheric Infrared Sounder (AIRS) is a space-based instrument that measures the upwelling atmospheric spectrum in the infrared. AIRS is one of several instruments on the EOS-Aqua spacecraft launched on May 4, 2002: Typically, instrument polarization is not a concern in the infrared because the scene is usually not significantly polarized. A small amount of polarization is expected over ocean, which can be seen in the AIRS 3.7 (micro)m window channels. The polarization is seen as a signal difference between two channels with the same center frequency but different polarizations. The observations are compared to a model that relies on measurements of instrument polarization made pre-flight. A first look at a comparison of the observations of sea surface polarization to expectations is presented.

  1. SI traceable algorithm for characterizing hyperspectral infrared sounder CrIS noise.

    PubMed

    Chen, Yong; Weng, Fuzhong; Han, Yong

    2015-09-10

    The Cross-track Infrared Sounder (CrIS) on the Suomi National Polar-orbiting Partnership Satellite (S-NPP) is a Fourier transform spectrometer and provides the sensor data record (SDR) that can be used to retrieve atmospheric temperature and water vapor profiles and can also be directly assimilated in numerical weather prediction models. The noise equivalent differential radiance (NEdN) is part of CrIS SDR products and represents the amount of random noise in the interferometer data. It is a crucial parameter that affects the accuracy of retrieval and satellite radiance assimilation. In this study, we used the international system of units (SI) traceable method Allan deviation to estimate the CrIS NEdN because the internal calibration target (ICT) radiance was slowly varying with time. Compared to the current standard deviation method, this study shows that the NEdN calculated from Allan deviation is converged to a stable value when a number of samples or the average window size is set to 510. Thus, Allan deviation can result in CrIS NEdN SI traceable noise. An optimal averaging window size is 30 if the NEdN is calculated from the standard deviation. PMID:26368960

  2. Improved methodology for surface and atmospheric soundings, error estimates, and quality control procedures: the atmospheric infrared sounder science team version-6 retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Susskind, Joel; Blaisdell, John M.; Iredell, Lena

    2014-01-01

    The atmospheric infrared sounder (AIRS) science team version-6 AIRS/advanced microwave sounding unit (AMSU) retrieval algorithm is now operational at the Goddard Data and Information Services Center (DISC). AIRS version-6 level-2 products are generated near real time at the Goddard DISC and all level-2 and level-3 products are available starting from September 2002. Some of the significant improvements in retrieval methodology contained in the version-6 retrieval algorithm compared to that previously used in version-5 are described. In particular, the AIRS science team made major improvements with regard to the algorithms used to (1) derive surface skin temperature and surface spectral emissivity; (2) generate the initial state used to start the cloud clearing and retrieval procedures; and (3) derive error estimates and use them for quality control. Significant improvements have also been made in the generation of cloud parameters. In addition to the basic AIRS/AMSU mode, version-6 also operates in an AIRS only (AO) mode, which produces results almost as good as those of the full AIRS/AMSU mode. The improvements of some AIRS version-6 and version-6 AO products compared to those obtained using version-5 are also demonstrated.

  3. EOS Microwave Limb Sounder Observations of 'Frozen-in' Anticyclonic Air in Arctic Summer

    NASA Technical Reports Server (NTRS)

    Manney, G. L.; Livesey, N. J.; Jimenez, C. J.; Pumphrey, H. C.; Santee, M. L.; MacKenzie, I. A.; Waters, J. W.

    2006-01-01

    A previously unreported phenomenon, a 'frozen-in' anticyclone (FrIAC) after the 2005 Arctic spring vortex breakup, was discovered in Earth Observing System (EOS) Microwave Limb Sounder (MLS) long-lived trace gas data. A tongue of low-latitude (high-N2O, low-H2O) air was drawn into high latitudes and confined in a tight anticyclone, then advected intact in the summer easterlies through late August. A similar feature in O3 disappeared by early April as a result of chemical processes. The FrIAC was initially advected upright at nearly the same speed at all levels from approx.660 to 1300 K (approx.25-45 km); increasing vertical wind shear after early June tilted the FrIAC and weakened it at higher levels. The associated feature in PV disappeared by early June; transport calculations fail to reproduce the remarkable persistence of the FrIAC, suggesting deficiencies in summer high-latitude winds. The historical PV record suggests that this phenomenon may have occurred several times before. The lack of a persistent signature in O3 or PV, along with its small size and rapid motion, make it unlikely that a FrIAC could have been reliably identified without hemispheric daily longlived trace gas profiles such as those from EOS MLS.

  4. Cross-Track Infrared Sounder Science Data Record Pre-launch Calibration and On-Orbit Validation Plans

    NASA Astrophysics Data System (ADS)

    Hagan, D. E.; Bingham, G. E.; Predina, J.; Gu, D.; Sabet-Peyman, F.; Wang, C.; de Amici, G.; Plonski, M.; Farrow, S. V.; Hohn, J.; Esplin, M.; Zavyalov, V.; Fish, C. S.; Glumb, R.; Wells, S.; Suwinski, L.; Strong, J.; Behrens, C.; Kilcoyne, H.; Feeley, J.; Kratz, G.; Tremblay, D. A.

    2009-12-01

    The Cross-Track Infrared Sounder (CrIS) together with the Advanced Technology Microwave Sounder will provide retrievals of atmospheric moisture and temperature profiles for the National Polar-orbiting Operational Environmental Satellite System (NPOESS). The NPOESS is the next generation of low Earth orbiting weather and climate satellites managed by the tri-agency Integrated Program Office, which includes the Department of Commerce, Department of Defense and the National Aeronautics and Space Administration. The CrIS is a Fourier-transform Michelson interferometer covering the spectral range of 3.9 to 15.4 microns (650 to 2550 wavenumbers) developed by ITT under contract to Northrop Grumman Aerospace Systems. The first deployment of the CrIS (Flight Model 1) is scheduled for 2010 on the NPOESS Preparatory Project (NPP) satellite, an early instrument risk reduction component of the NPOESS mission. The analysis and data results from comprehensive TVAC testing of the CrIS FM1 sensor demonstrate a very accurate radiometric and spectral calibration system. We describe instrument performance parameters, and the end-to-end plans and analysis tools for on-orbit verification of sensor characteristics and validation of the SDR radiance products.

  5. Comparison of OLR Data Sets from AIRS, CERES and MERRA 2

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Susskind, Joel; Iredell, Lena; Loeb, Norman; Lim, Young-Kwon

    2015-01-01

    Organizers of the NASA Sounder Science Team Meeting would like to post the presentations to a the JPL Atmospheric Infrared Sounder (AIRS) publicly-available website. The meeting was held in Greenbelt, Maryland, October 13-16, 2015.

  6. Role of the advanced IR sounder in land surface remote sensing

    NASA Astrophysics Data System (ADS)

    Knuteson, Robert O.

    2005-09-01

    A new era of Earth remote sensing began with the launch of the NASA EOS Aqua platform with the Atmospheric InfraRed Sounder (AIRS) in May 2002. The EOS AIRS instrument is the first in a series of high spectral resolution infrared spectrometers that will allow improved characterization of the global atmospheric temperature and water vapor structure. Follow-on operational sensors with similar sounding capability include the Cross-track InfraRed Sounder (CrIS) on the NPP/NPOESS satellites and the Infrared Advanced Sounding Interferometer (IASI) on the European METOP series. These so-called advanced infrared sounders will have a vital role to play in the remote sensing of land ecosystems. This paper describes how the use of Advanced IR Sounder data can be used to improve the accuracy of atmospheric corrections in the thermal IR and provide detailed information on the spectral dependence of the infrared land surface emissivity. Radiance observations from AIRS have been obtained over a large, uniform sandy desert region in the Libyan Desert suitable for evaluation of the 15-km footprints of the NASA AIRS advanced sounder. Analysis of this data indicates a spectral contrast of more than 30% between 12 mm and 9 mm in the surface infrared emissivity due to the presence of the mineral quartz with somewhat smaller contrast at 4 mm. Results of a method for separation of infrared surface emissivity and effective surface skin temperature are presented also.

  7. Simultaneous physical retrieval of surface emissivity spectrum and atmospheric parameters from infrared atmospheric sounder interferometer spectral radiances.

    PubMed

    Masiello, Guido; Serio, Carmine

    2013-04-10

    The problem of simultaneous physical retrieval of surface emissivity, skin temperature, and temperature, water-vapor, and ozone atmospheric profiles from high-spectral-resolution observations in the infrared is formulated according to an inverse problem with multiple regularization parameters. A methodology has been set up, which seeks an effective solution to the inverse problem in a generalized L-curve criterion framework. The a priori information for the surface emissivity is obtained on the basis of laboratory data alone, and that for the atmospheric parameters by climatology or weather forecasts. To ensure that we deal with a problem of fewer unknowns than observations, the dimensionality of the emissivity is reduced through expansion in Fourier series. The main objective of this study is to demonstrate the simultaneous retrieval of emissivity, skin temperature, and atmospheric parameters with a two-dimensional L-curve criterion. The procedure has been demonstrated with spectra observed from the infrared atmospheric sounder interferometer, flying onboard the European Meteorological Operational satellite. To check the quality and reliability of the methodology, we have used spectra recorded over regions characterized by known or stable emissivity. These include sea surface, for which effective emissivity models are known, and arid lands (Sahara and Namib Deserts) that are known to exhibit the characteristic spectral signature of quartz-rich sand. PMID:23670773

  8. Application of Spaceborne Infrared Atmospheric Sounder for Geosynchronous Earth Orbit (SIRAS-G) technology to future Earth science missions

    NASA Astrophysics Data System (ADS)

    Kampe, Thomas U.

    2008-04-01

    The Spaceborne Infrared Sounder for Geosynchronous Earth Orbit (SIRAS-G) was developed by Ball Aerospace & Technologies Corp (BATC) under NASA's 2002 Instrument Incubator Program. SIRAS-G was a technology development program focused on next-generation IR imaging spectrometers for sounding of the atmosphere. SIRAS-G demonstrated that the dispersive grating spectrometer is a suitable instrument architecture for this application. In addition to providing atmospheric temperature and water vapor profiles, SIRAS-G can provide trace gases concentrations, land and ocean surface temperatures and the IR mineral dust aerosol signature from satellite. The 3-year SIRAS-G IIP development effort included the successful cryogenic testing of the SIRAS-G laboratory demonstration spectrometer operating in the 2083 to 2994 cm -1 frequency range. The performance of the demonstration instrument has been quantified including measurement of keystone distortion, spectral smile, MTF, and the spectral response function (SRF). Development efforts associated with this advanced infrared spectrometer technology provides the basis for instrumentation to support future Earth science missions.

  9. Impacts of field of view configuration of Cross-track Infrared Sounder on clear-sky observations.

    PubMed

    Wang, Likun; Chen, Yong; Han, Yong

    2016-09-01

    Hyperspectral infrared radiance measurements from satellite sensors contain valuable information on atmospheric temperature and humidity profiles and greenhouse gases, and therefore are directly assimilated into numerical weather prediction (NWP) models as inputs for weather forecasting. However, data assimilations in current operational NWP models still mainly rely on cloud-free observations due to the challenge of simulating cloud-contaminated radiances when using hyperspectral radiances. The limited spatial coverage of the 3×3 field of views (FOVs) in one field of regard (FOR) (i.e., spatial gap among FOVs) as well as relatively large footprint size (14 km) in current Cross-track Infrared Sounder (CrIS) instruments limits the amount of clear-sky observations. This study explores the potential impacts of future CrIS FOV configuration (including FOV size and spatial coverage) on the amount of clear-sky observations by simulation experiments. The radiance measurements and cloud mask products (VCM) from the Visible Infrared Imager Radiometer Suite (VIIRS) are used to simulate CrIS clear-sky observation under different FOV configurations. The results indicate that, given the same FOV coverage (e.g., 3×3), the percentage of clear-sky FOVs and the percentage of clear-sky FORs (that contain at least one clear-sky FOV) both increase as the FOV size decreases. In particular, if the CrIS FOV size were reduced from 14 km to 7 km, the percentage of clear-sky FOVs increases from 9.02% to 13.51% and the percentage of clear-sky FORs increases from 18.24% to 27.51%. Given the same FOV size but with increasing FOV coverage in each FOR, the clear-sky FOV observations increases proportionally with the increasing sampling FOVs. Both reducing FOV size and increasing FOV coverage can result in more clear-sky FORs, which benefit data utilization of NWP data assimilation. PMID:27607289

  10. Space View Issues for Hyperspectral Sounders

    NASA Technical Reports Server (NTRS)

    Manning, Evan M.; Aumann, Hartmut H.; Broberg, Steven E.

    2013-01-01

    The expectation for climate quality measurements from hyperspectral sounders is absolute calibration accuracy at the 100 mK level and stability at the < 40 mK/decade level. The Atmospheric InfraRed Sounder (AIRS)1, Cross-track Infrared Sounder (CrIS), and Infrared Atmospheric Sounding Interferometer (IASI) hyperspectral sounders currently in orbit have been shown to agree well over most of their brightness temperature range. Some larger discrepancies are seen, however, at the coldest scene temperatures, such as those seen in Antarctic winter and deep convective clouds. A key limiting factor for the calibrated scene radiance accuracy for cold scenes is how well the effective radiance of the cold space view pertains to the scene views. The space view signal is composed of external sources and instrument thermal emission at about 270 K from the scan mirror, external baffles, etc. Any difference in any of these contributions between space views and scene views will impact the absolute calibration accuracy, and the impact can be critical for cold scenes. Any change over time in these will show up as an apparent trend in calibrated radiances. We use AIRS data to investigate the validity of the space view assumption in view of the 100 mK accuracy and 40 mK/decade trend expectations. We show that the space views used for the cold calibration point for AIRS v5 Level-1B products meet these standards except under special circumstances and that AIRS v6 Level-1B products will meet them under all circumstances. This analysis also shows the value of having multiple distinct space views to give operational redundancy and analytic data, and that reaching climate quality requires continuing monitoring of aging instruments and adjustment of calibration.

  11. A Comparison of the Red Green Blue Air Mass Imagery and Hyperspectral Infrared Retrieved Profiles

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Folmer, Michael; Dunion, Jason

    2014-01-01

    The Red Green Blue (RGB) Air Mass imagery is derived from multiple channels or paired channel differences. Multiple channel products typically provide additional information than a single channel can provide alone. The RGB Air Mass imagery simplifies the interpretation of temperature and moisture characteristics of air masses surrounding synoptic and mesoscale features. Despite the ease of interpretation of multiple channel products, the combination of channels and channel differences means the resulting product does not represent a quantity or physical parameter such as brightness temperature in conventional single channel satellite imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles of temperature, moisture, and ozone can provide insight about the air mass represented on the RGB Air Mass product and provide confidence in the product and representation of air masses despite the lack of a quantity to reference for interpretation. This study focuses on RGB Air Mass analysis of Hurricane Sandy as it moved north along the U.S. East Coast, while transitioning to a hybrid extratropical storm. Soundings and total column ozone retrievals were analyzed using data from the Cross-track Infrared and Advanced Technology Microwave Sounder Suite (CrIMSS) on the Suomi National Polar Orbiting Partnership satellite and the Atmospheric Infrared Sounder (AIRS) on the National Aeronautics and Space Administration Aqua satellite along with dropsondes that were collected from National Oceanic and Atmospheric Administration and Air Force research aircraft. By comparing these datasets to the RGB Air Mass, it is possible to capture quantitative information that could help in analyzing the synoptic environment enough to diagnose the onset of extratropical transition. This was done by identifying any stratospheric air intrusions (SAIs) that existed in the vicinity of Sandy as the wind

  12. SAFIRE-A: An airborne far infra-red limb sounder

    SciTech Connect

    Dickinson, P.; Carli, B.; Ade, P.; Nolt, I.; Leotin, J.; Carlotti, M.

    1995-12-31

    The design and scientific objectives of the SAFIRE-A (Spectroscopy of the Atmosphere using Far Infra-Red Emissions-Airborne) instrument will be described. The instrument exploits technical developments achieved during the development of the SAFIRE concept for space. These include an interferometer of compact design with spectral resolution 0.004 cm{sup {minus}1}, and narrow-band filters (2 cm{sup {minus}1} wide) to reduce photon noise. The instrument is capable of detecting ozone and trace gases that affect ozone depletion, for example OH, HO{sub 2}, H{sub 2}O{sub 2}, HOCl, HCl, ClO, HF, HBr and also H{sub 2}O. The measurements will include column content above the aircraft (above 20 km) and height resolved abundances at lower altitudes.

  13. An Anomaly Correlation Skill Score for the Evaluation of the Performance of Hyperspectral Infrared Sounders

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Manning, Evan; Barnet, Chris; Maddy, Eric; Blackwell, William

    2009-01-01

    With the availability of very accurate forecasts, the metric of accuracy alone for the evaluation of the performance of a retrieval system can produce misleading results. A useful characterization of the quality of a retrieval system and its potential to contribute to an improved weather forecast is its skill, which we define as the ability to make retrievals of geophysical parameters which are closer to the truth than the six hour forecast, when the truth differs significantly from the forecast. We illustrate retrieval skill using one day of AMSU and AIRS data with three different retrieval algorithms, which result in retrievals for more than 90% of the potential retrievals under clear and cloudy conditions. Two of the three algorithms have better than 1 K rms "RAOB quality" accuracy on the troposphere, but only one has skill between 900 and 100 mb. AIRS was launched on the EOS Aqua spacecraft in May 2002 into a 705 km polar sun-synchronous orbit with accurately maintained 1:30 PM ascending node. Essentially uninterrupted data are freely available since September 2002.

  14. Visible infrared spin-scan radiometer atmospheric sounder radiometric calibration - An inflight evaluation from intercomparisons with HIRS and radiosonde measurements

    NASA Technical Reports Server (NTRS)

    Menzel, W. P.; Smith, W. L.; Herman, L. D.

    1981-01-01

    The ability to conduct soundings from a geostationary platform has been demonstrated with the Visible IR spin-scan radiometer Atmospheric Sounder (VAS) aboard GOES-4. While a negative offset reaching 2.0-3.0 C for the upper atmospheric CO2 bands of VAS was observed in comparisons with High Resolution IR Radiation Sounder (HIRS) measurements and analyses of radiosonde data, VAS radiances are consistent with that material. After removing the offset, the temperature profiles derived from VAS radiances agree very well with those observed by radiosondes. Time variations in the atmospheric state are discernible from VAS soundings at three-hour intervals, and were confirmed by radiosonde observations.

  15. Ammonia Measurements by the NASA Tropospheric Emission Spectrometer (TES) and the NPP Suomi Cross-Track Infrared Sounder (CrIS)

    NASA Astrophysics Data System (ADS)

    Cady-Pereira, K. E.; Shephard, M. W.; Henze, D. K.; Zhu, J.; Pinder, R. W.; Bash, J. O.; Walker, J. T.; Luo, M.

    2013-12-01

    models of the ammonia bi-directional exchange at the surface and we will show some preliminary ammonia retrievals from the Cross-track Infrared Sounder (CrIS) currently flying on the NASA NPP Suomi satellite.

  16. Three Years of Hyperspectral Data from AIRS: What Have We Learned

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut. H.; Chahine, Moustafa T.; Pagano, Thomas S.

    2006-01-01

    This viewgraph presentation reviews the Atmospheric Infrared Sounder (AIRS) that is on the Aqua satellite. The expectations that were had about AIRS have been exceeded. The lessons learned from AIRS are reviewed. These lessons are used to enhance the next generation hyperspectral sounder, being planned.

  17. AIRS Level 1b Algorithm Theoretical Basis Document

    NASA Technical Reports Server (NTRS)

    Aumann, H.; Gregorich, D.; Gaiser, S.; Hagan, D.; Pagano, T.; Ting, D.

    2000-01-01

    The level 1b Algorithm Theoretical Basis Document (ATBD) describes the theoretical bases of the algorithms used to convert the raw detector output (data numbers) from the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU) and Humidity Sounder Brazil (HSB) to physical radiance units and, in the case of AIRS, perform in-orbit spectral calibrations.

  18. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, Charles H.; Laux, C. O.

    2001-01-01

    This report summarizes the results obtained during a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University under the direction of Professor Charles H. Kruger, with Dr. Christophe O. Laux as Associate Investigator. The goal of this research was to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. To this end, spectral measurements and modeling were made of the radiation emitted between 2.4 and 5.5 micrometers by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3000 K. The objective was to examine the spectral emission of air species including nitric oxide, atomic oxygen and nitrogen lines, molecular and atomic continua, as well as secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million of CO2, which is the natural CO2 concentration in atmospheric air at room temperatures, and a small amount of water vapor with an estimated mole fraction of 3.8x10(exp -4).

  19. Full Spectral Resolution Data Generation from the Cross-track Infrared Sounder on S-NPP at NOAA and its Use to Investigate Uncertainty in Methane Absorption Band Near 7.66 µm

    NASA Astrophysics Data System (ADS)

    Xiong, X.; Peischl, J.; Ryerson, T. B.; Sasakawa, M.; Han, Y.; Chen, Y.; Wang, L.; Tremblay, D.; Jin, X.; Zhou, L.; Liu, Q.; Weng, F.; Machida, T.

    2015-12-01

    The Cross-track Infrared Sounder (CrIS) on Suomi National Polar-orbiting Partnership Satellite (S-NPP) is a Fourier transform spectrometer for atmospheric sounding. CrIS on S-NPP started to provide measurements in 1305 channels in its normal mode since its launch on November 2011 to December 4, 2014, and after that it was switched to the full spectral resolution (FSR) mode, in which the spectral resolutions are 0.625 cm-1 in all the MWIR (1210-1750 cm-1), SWIR (2155-2550 cm-1) and the LWIR bands (650-1095 cm-1) with a total of 2211 channels. While the NOAA operational Sensor Data Record (SDR) processing (IDPS) continues to produce the normal resolution SDRs by truncating full spectrum RDR data, NOAA STAR started to process the FSR SDRs data since December 4, 2014 to present, and the data is being delivered through NOAA STAR website (ftp://ftp2.star.nesdis.noaa.gov/smcd/xxiong/). The current FSR processing algorithm was developed on basis of the CrIS Algorithm Development Library (ADL), and is the baseline of J-1 CrIS SDR algorithm. One major benefit to use the FSR data is to improve the retrieval of atmospheric trace gases, such as CH4, CO and CO2 . From our previous studies to retrieve CH4 using Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI), it was found the uncertainty in the CH4 absorption band is up to 1-2%. So, in this study we computed the radiance using the community radiative transfer model (CRTM) and line-by-line model, with the inputs of "truth" of atmospheric temperature and moisture profiles from ECMWF model (and/or RAOB sounding) and CH4 profiles from in-situ aircraft measurements, then convoluted with the response function of CrIS. The difference between the simultaed radiance and the collocated CrIS FSR data is used to exam the uncertainty in these strong absorption channels.Through the improved fitting to the transmittance in these channels, it is expected to improve the retrieval of CH4 using CrIS on S

  20. Cloud characteristics over central Amazonia during GTE/ABLE 2B derived from multispectral visible and infrared spin scan radiometer atmospheric sounder observations

    SciTech Connect

    Menzel, W.P. ); Schmit, T.J.; Wylie, D.P. )

    1990-09-20

    Multispectral GOES/Visible and Infrared Spin Scan Radiometer Atmospheric Sounder (VAS) observations in the carbon dioxide absorption band at 15 {mu}m have been used to calculate diurnal cloud statistics over central Amazonia region for 4 days during the Global Tropospheric Experiment/Amazon Boundary Layer Experiment (GTE/ABLE IIB). The CO{sub 2} technique calculates both cloud top pressure and effective emissivity from radiative transfer principles. Transmissive clouds that are partially transparent to terrestrial radiation have been reliably separated from opaque clouds in the statistics of cloud cover. A high incidence of transmissive clouds (about 47%) was found on the average. Diurnal characteristics of cloud cover over Amazonia have been linked to convective activity over this region. On days with afternoon convection, an increase in low-altitude opaque clouds was followed by a subsequent increase in high-altitude transmissive clouds.

  1. Climate Change and Sounder Radiometric Stability

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Manning, Evan

    2009-01-01

    Satellite instrument radiometric stability is critical for climate studies. The Atmospheric Infrared Sounder (AIRS) radiances are of sufficient stability and accuracy to serve as a climate data record as evidenced by comparisons with the global network of buoys. In this paper we examine the sensitivity of derived geophysical products to potential instrument radiometric stability issues due to diurnal, orbital and seasonal variations. Our method is to perturb the AIRS radiances and examine the impact to retrieved parameters. Results show that instability in retrieved temperature products will be on the same order of the brightness temperature error in the radiances and follow the same time dependences. AIRS excellent stability makes it ideal for examining impacts of instabilities of future systems on geophysical parameter performance.

  2. Cirrus cloud optical and microphysical properties determined from AIRS infrared spectra

    NASA Astrophysics Data System (ADS)

    Yue, Qing; Liou, K. N.

    2009-03-01

    We developed an efficient thermal infrared radiative transfer model on the basis of the delta-four-stream approximation to facilitate high-spectral-resolution remote sensing applications under cirrus cloudy conditions in the Atmospheric Infrared Sounder (AIRS) data. Numerical experiments demonstrated that sensitivity in the 800-1130 cm-1 thermal infrared window spectral region is sufficiently distinct for the inference of cirrus optical depth and ice crystal mean effective size and shape factor. We analyzed 312 nighttime cirrus pixels in two AIRS granules over ARM TWP sites and applied the radiative transfer model to these cases to determine cirrus optical depth and ice crystal mean effective size, based on a look-up table approach. The retrieval program has been evaluated through an error budget analysis and validation effort by comparing AIRS-retrieved results with those determined from ground-based millimeter-wave cloud radar data at ARM TWP sites, for five AIRS pixels that were collocated and coincident with ground-based measurements.

  3. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    This report describes progress during the second year of our research program on Infrared Signature Masking by Air Plasmas at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Our previous annual report described spectral measurements and modeling of the radiation emitted between 3.2 and 5.5 microns by an atmospheric pressure air plasma in chemical and thermal equilibrium at a temperature of approximately 3100 K. One of our goals was to examine the spectral emission of secondary species such as water vapor or carbon dioxide. The cold air stream injected in the plasma torch contained approximately 330 parts per million Of CO2, which is the natural CO2 concentration in atmospheric air at room temperature, and a small amount of water vapor with an estimated mole fraction of 3.8 x 10(exp -4). As can be seen from Figure 1, it was found that the measured spectrum exhibited intense spectral features due to the fundamental rovibrational bands of NO at 4.9 - 5.5 microns and the V(3) band of CO2 (antisymmetric stretch) at 4.2-4.8 microns. These observations confirmed the well-known fact that infrared signatures between 4.15 - 5.5 microns can be masked by radiative emission in the interceptor's bow-shock. Figure I also suggested that the range 3.2 - 4.15 microns did not contain any significant emission features (lines or continuum) that could mask IR signatures. However, the signal-to-noise level, close to one in that range, precluded definite conclusions. Thus, in an effort to further investigate the spectral emission in the range of interest to signature masking problem, new measurements were made with a higher signal-to-noise ratio and an extended wavelength range.

  4. AIRS Infrared Radiance Validation Concept Using Earth Scene Observations

    NASA Astrophysics Data System (ADS)

    Hagan, D. E.; Aumann, H. H.; Pagano, T. S.; Strow, L. L.

    2001-05-01

    The Atmospheric Infrared Sounder (AIRS) will fly onboard the NASA Earth Observing Satellite (EOS)polar-orbiting Aqua spacecraft. AIRS, a high resolution infrared spectrometer with visible and near-infrared spectral channels, has been designed to provide atmospheric temperature and moisture profiles at least as accurate as those measured by standard radiosondes. Calibration studies of the response of each of the AIRS 4000+ detectors will begin as soon as the spacecraft orbit and instrument have stabilized. These studies are needed to help assess the contribution of instrument measurement errors to the spectral radiance determination. Some of the uncertainties will be determined from measurements of the onboard calibrators. Other sources of measurement uncertainty, such as scan mirror polarization and spectral response functions, require views of Earth at nadir and at oblique viewing angles, in cloud-free conditions. During early operation of the instrument, the blackbody radiance determination will rely on pre-launch measurements and models of the spectral response functions. During this phase of the operation, we have chosen an approach for initial assessment of the accuracy of the measured radiance that is not dependent on an exact knowledge of the spectral position of the detectors. Radiances will be evaluated in narrow regions that are well removed from spectral line features. There are potentially hundreds of detectors that can be used for this purpose. Our work to date has focused on a subset of these detectors located in atmospheric window regions between 2500-2700 cm-1 and 800-1200 cm-1. Pre-launch thermal-vacuum blackbody calibration results indicate that, using a reasonable cross-section of detectors, it should be possible to extrapolate the performance of a sparse set of detectors to the general state of the instrument calibration. In this paper we describe some initial results using a simple statistical methodology that compares outgoing radiances in

  5. Low-level water vapor fields from the VISSR atmospheric sounder (VAS) split window channels at 11 and 12 microns. [visible infrared spin scan radiometer

    NASA Technical Reports Server (NTRS)

    Chesters, D.; Uccellini, L.; Robinson, W.

    1982-01-01

    A series of high-resolution water vapor fields were derived from the 11 and 12 micron channels of the VISSR Atmospheric Sounder (VAS) on GOES-5. The low-level tropospheric moisture content was separated from the surface and atmospheric radiances by using the differential adsorption across the 'split window' along with the average air temperature from imbedded radiosondes. Fields of precipitable water are presented in a time sequence of five false color images taken over the United States at 3-hour intervals. Vivid subsynoptic and mesoscale patterns evolve at 15 km horizontal resolution over the 12-hour observing period. Convective cloud formations develop from several areas of enhanced low-level water vapor, especially where the vertical water vapor gradient relatively strong. Independent verification at radiosonde sites indicates fairly good absolute accuracy, and the spatial and temporal continuity of the water vapor features indicates very good relative accuracy. Residual errors are dominated by radiometer noise and unresolved clouds.

  6. Satellite-based Hyperspectral Sounder Retrievals in Real-time Weather Applications

    NASA Astrophysics Data System (ADS)

    Weisz, E.; Smith, N.; Smith, W. L.

    2015-12-01

    Real-time weather monitoring and forecasting abilities have significantly improved by the new generation of weather satellites, which provide routine access to observations and atmospheric data. In addition of providing visual images, satellite-based instrumentation also provide spectral radiance data that allow the computation of atmospheric temperature, moisture and trace gas profiles and other geophysical variables including cloud parameters. Hyperspectral sounders, AIRS (Atmospheric Infrared Sounder), IASI (Infrared Atmospheric Sounding Interferometer) and CrIS (Cross-track Infrared Sounder) on low-Earth orbiting satellites, provide atmospheric profiles on a global scale with the spatial and temporal resolution needed to complement traditional profile data sources such as that obtained by radiosondes. The goal of this paper is to describe the information that hyperspectral sounders are capable of adding to weather monitoring and short-term forecasting systems. Retrievals derived from all four operational sounders are used in time-series to describe the pre-convective environment (including moisture advection and stability tendencies) antecedent to the initiation of severe weather. Temporal and spatial consistency and continuity is achieved among different instruments on different platforms through the use of a single atmospheric profile retrieval algorithm. Our results demonstrate the utility of using hyperspectral sounding products from multiple satellites for the real-time weather monitoring/prediction operation.

  7. Trends in South American biomass burning detected with the GOES visible infrared spin scan radiometer atmospheric sounder from 1983 to 1991

    SciTech Connect

    Prins, E.M.; Menzel, W.P. |

    1994-08-01

    Previous work demonstrated the ability to manually detect subpixel fire activity in selected areas of the selva and cerrado regions in South America with shortwave and longwave infrared data available from the Geostationary Operational Environmental Satellite (GOES) visible infrared spin scan radiometer atmospheric sounder (VAS). This paper presents the GOES VAS automated biomass-burning algorithm (ABBA) which was developed to determine basin-wide trends in fire activity in South America utilizing the GOES VAS archive. Comparisons between the manual and automated techniques revealed that overall, the ABBA proved to be more consistent in identifying fires and better suited for trend analysis. The automated algorithm was applied daily to a study area extending from 5 deg S to 15 deg S and from 45 deg W to 70 deg W for 2 weeks at the peak of the burning seasons in South America in 1983, 1988, 1989, and 1991 in an effort to measure the areal extent of burning in South American during the past decade and to provide additional insight into the diurnal signature in satellite detection of biomass-burning activities. The expansion of the regions of burning are readily detected in a comparison of these 4 years. From 1983 to 1991 the amount of burning detected by the GOES VAS ABBA during these 2-week periods nearly doubled in the selva and mixed regions and tripled in the cerrado. Diurnal analyses confirmed earlier results indicating that the optimum time to monitor biomass burning is around 1530 UTC.

  8. Trends in South American biomass burning detected with the GOES visible infrared spin scan radiometer atmospheric sounder from 1983 to 1991

    NASA Technical Reports Server (NTRS)

    Prins, Elain M.; Menzel, W. Paul

    1994-01-01

    Previous work demonstrated the ability to manually detect subpixel fire activity in selected areas of the selva and cerrado regions in South America with shortwave and longwave infrared data available from the Geostationary Operational Environmental Satellite (GOES) visible infrared spin scan radiometer atmospheric sounder (VAS). This paper presents the GOES VAS automated biomass-burning algorithm (ABBA) which was developed to determine basin-wide trends in fire activity in South America utilizing the GOES VAS archive. Comparisons between the manual and automated techniques revealed that overall, the ABBA proved to be more consistent in identifying fires and better suited for trend analysis. The automated algorithm was applied daily to a study area extending from 5 deg S to 15 deg S and from 45 deg W to 70 deg W for 2 weeks at the peak of the burning seasons in South America in 1983, 1988, 1989, and 1991 in an effort to measure the areal extent of burning in South American during the past decade and to provide additional insight into the diurnal signature in satellite detection of biomass-burning activities. The expansion of the regions of burning are readily detected in a comparison of these 4 years. From 1983 to 1991 the amount of burning detected by the GOES VAS ABBA during these 2-week periods nearly doubled in the selva and mixed regions and tripled in the cerrado. Diurnal analyses confirmed earlier results indicating that the optimum time to monitor biomass burning is around 1530 UTC.

  9. NIRATAM-NATO infrared air target model

    NASA Astrophysics Data System (ADS)

    Noah, Meg A.; Kristl, Joseph; Schroeder, John W.; Sandford, B. P.

    1991-08-01

    NIRATAM (the NATO Infrared Air Target Model) was developed by the NATO AC 243, Panel IV, Research Study Group 6 (RSG-6). RSG-6 is composed of representatives from Denmark, France, Germany, Italy, the Netherlands, the United Kingdom, the United States of America, and Canada (as an observer). NIRATAM is based on theoretical studies, field measurements, and infrared data analysis performed over many years. The model encompasses all the major signature components required to simulate the infrared signature of an aircraft and the atmosphere. The vehicle fuselage, facet, model includes radiation due to aerodynamic heating, internal heat sources, reflected sky, earth, and solar radiation. Plume combustion gas emissions are calculated for H(subscript 2)O, CO(subscript 2), CO, and other gases as well as solid particles. Lowtran 7 is used for the atmospheric transmission and radiance. The software generates graphical outputs of the target wireframe, plume flowfield, atmospheric transmission, total signature, and plume signature. Imagery data can be used for system development and evaluation. NIRATAM can be used for many applications such as measurement planning, data analysis, systems design, and aircraft development. Ontar has agreed to assist the RSG-6 by being the NIRATAM distribution center in the United States for users approved by the national representatives. Arrangements have also been made to distribute a user-friendly NIRATAM interface. This paper describes the model, presents results, makes comparisons with measured field data, and describes the availability and procedure for obtaining the software.

  10. Assimilation of IASI and AIRS Data: Information Content and Quality Control

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) and Atmospheric Infrared Sounder (AIRS) instruments have two orders of magnitude more channels that the current operational infrared sounder (High Resolution Infra-Red Sounder (HIRS)). This data volume presents a technological challenge for using the data in a data assimilation system. Data reduction will be a necessary for assimilation. It is important to understand the information content of the radiance measurements for data reduction purposes. In this talk, I will discuss issues relating to information content and quality control for assimilation of the AIRS and IASI data.

  11. Assessment of error propagation in ultraspectral sounder data via JPEG2000 compression and turbo coding

    NASA Astrophysics Data System (ADS)

    Olsen, Donald P.; Wang, Charles C.; Sklar, Dean; Huang, Bormin; Ahuja, Alok

    2005-08-01

    Research has been undertaken to examine the robustness of JPEG2000 when corrupted by transmission bit errors in a satellite data stream. Contemporary and future ultraspectral sounders such as Atmospheric Infrared Sounder (AIRS), Cross-track Infrared Sounder (CrIS), Infrared Atmospheric Sounding Interferometer (IASI), Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS), and Hyperspectral Environmental Suite (HES) generate a large volume of three-dimensional data. Hence, compression of ultraspectral sounder data will facilitate data transmission and archiving. There is a need for lossless or near-lossless compression of ultraspectral sounder data to avoid potential retrieval degradation of geophysical parameters due to lossy compression. This paper investigates the simulated error propagation in AIRS ultraspectral sounder data with advanced source and channel coding in a satellite data stream. The source coding is done via JPEG2000, the latest International Organization for Standardization (ISO)/International Telecommunication Union (ITU) standard for image compression. After JPEG2000 compression the AIRS ultraspectral sounder data is then error correction encoded using a rate 0.954 turbo product code (TPC) for channel error control. Experimental results of error patterns on both channel and source decoding are presented. The error propagation effects are curbed via the block-based protection mechanism in the JPEG2000 codec as well as memory characteristics of the forward error correction (FEC) scheme to contain decoding errors within received blocks. A single nonheader bit error in a source code block tends to contaminate the bits until the end of the source code block before the inverse discrete wavelet transform (IDWT), and those erroneous bits propagate even further after the IDWT. Furthermore, a single header bit error may result in the corruption of almost the entire decompressed granule. JPEG2000 appears vulnerable to bit errors in a noisy channel of

  12. EMI Performance of the AIRS Cooler and Electronics

    NASA Technical Reports Server (NTRS)

    Johnson, D.; Collins, S.; Ross, R.

    1998-01-01

    The TRW pulse tube cryocooler for JPL's Atmospheric Infrared Sounder (AIRS) instrument is required to meet stringent requirements for radiated electric and magnetic fields, conducted emissions on the input power bus, and electromagnetic susceptivility.

  13. Performance expectations for future moderate resolution visible and infrared space instruments based on AIRS and MODIS in-flight experience

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Broberg, Steven E.; Aumann, Hartmut H.; Baron, Richard L.

    2005-01-01

    Lessons learned from the Atmospheric Infrared Sounder (AIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) projects highlight areas where further technology development is needed to address future land, ocean and atmospheric measurement needs. Although not established as requirements at this time, it is anticipated that scientists will expect improvements in the areas of spatial, spectral, radiometric, polarimetric, temporal and calibration performance for future instruments. This paper addresses each of these performance areas and provides lessons learned from MODIS and AIRS. We also present expectations in performance of a Medium Earth Orbit (MEO) Infrared Imaging Spectrometer based on information from the NASA Instrument Incubator Program and industry reports. Tradeoffs are presented vs orbit altitude (LEO, MEO and GEO) and provide a "systems" perspective to future measurement concepts.

  14. Retrieval of atmospheric temperature and moisture vertical profiles from satellite Advanced Infrared Sounder radiances with a new regularization parameter selecting method

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Wu, Chunqiang; Li, Jun

    2016-06-01

    Considering the characteristics of nonlinear problems, a new method based on the L-curve method and including the concept of entropy was designed to select the regularization parameter in the one-dimensional variational analysis-based sounding retrieval method. In the first iteration, this method uses an empirical regularization parameter derived by minimizing the entropy of variables. During subsequent iterations, it uses the L-curve method to select the regularization parameter in the vicinity of the regularization parameter selected in the last iteration. The new method was employed to select the regularization parameter in retrieving atmospheric temperature and moisture profiles from Atmospheric Infrared Sounder radiance measurements selected from the first day of each month in 2008. The results show that compared with the original L-curve method, the new method yields 5.5% and 2.5% improvements on temperature and relative humidity profiles, respectively. Compared with the discrepancy principle method, the improvements on temperature and relative humidity profiles are 1.6% and 2.0%, respectively.

  15. Potential Enhancements to the Cross-track Infrared Sounder (CrIS) Ground Test, Data Downlink and Processing for Climate Monitoring including Trace Gas Retrievals

    NASA Astrophysics Data System (ADS)

    Farrow, S. V.; Christensen, T.; Hagan, D. E.

    2009-12-01

    Together with ATMS, the Cross-track Infrared Sounder (CrIS) sensor is a critical payload for National Polar-orbiting Operational Environmental Satellite System (NPOESS) and will first fly on the NPOESS Preparatory Project (NPP) mission, the risk reduction flight for NPOESS. NPOESS is the next generation weather and climate monitoring system for the Department of Defense and National Oceanic and Atmospheric Administration (NOAA), being developed under contract by Northrop Grumman Aerospace Systems. The paper describes potential changes to the program baseline to make CrIS data useful for climate monitoring, including trace gas retrievals such as CO2. Specifically, these are changes to ground calibration tests, changes to the Sensor Data Record (SDR) algorithm, and changes in the spacecraft interface to downlink all of the spectral channels the sensor produces. These changes are presented to promote discussion in the science community of an alternative to achieving some of the key requirements of NASA's OCO mission, which was to monitor CO2, but was destroyed during launch.

  16. Validation of the GOSAT Thermal Infrared (TIR) Band using the University of Wisconsin airborne Scanning High-resolution Interferometer Sounder (S-HIS) and ground-based Atmospheric Emitted Radiance Interferometer (AERI) at Railroad Valley, Nevada

    NASA Astrophysics Data System (ADS)

    Knuteson, R.; kuze, A.; Shiomi, K.; Taylor, J. K.; Garms, E.; Roman, J.; Revercomb, H. E.; Tobin, D. C.; Gero, P.; Best, F. A.

    2011-12-01

    We provide a quantitative assessment of the calibration accuracy of the thermal infrared measurements from the Greenhouse Gases Observing SATellite (GOSAT), which was launched on January 23, 2009. Results will be presented comparing the observed emission spectra from the TANSO-FTS sensor onboard GOSAT to coincident observations from high altitude aircraft and ground-based spectrometers during the June 2011 Railroad Valley Vicarious Calibration and Validation campaign. The 2011 campaign was the third in a series of joint Japan/U.S. field measurements to assess the calibration of the GOSAT sensors and validate derived products of carbon dioxide and methane. As part of the 2011 campaign, the University of Wisconsin Scanning High-resolution Interferometer Sounder (S-HIS) successfully overflew Railroad Valley, Nevada onboard the high-altitude NASA ER-2 along with the Airborne Visible/InfraRed Imaging Spectrometer (AVIRIS) and the MODIS/ASTER Airborne Simulator (MASTER). The ER-2 overpass of Railroad Valley on June 20, 2011 was timed to coincide with an overpass of the GOSAT satellite at 21:19 UTC. A joint JPL/UWisc team provided coincident upper air observations of pressure, temperature, and water vapor using Vaisala radiosondes released from the center of the Railroad Valley dry lakebed (playa) for six GOSAT daytime overpasses and three nighttime overpasses between 19-26 June 2011. The University of Wisconsin also made ground-based measurements from the center of the playa during each GOSAT overpass with an Atmospheric Emitted Radiance Interferometer. The AERI was operated from a research vehicle with the capability to measure the upwelling surface radiance at three view angles and the downwelling atmospheric emission at two angles. The ground-based AERI provided accurate surface emissivity and surface temperature for use in forward model calculations of the satellite observed infrared emission between 6 and 17 microns.

  17. Trends in South American biomass burning detected with the GOES visible infrared spin scan radiometer atmospheric sounder from 1983 to 1991

    NASA Astrophysics Data System (ADS)

    Prins, Elaine M.; Menzel, W. Paul

    1994-08-01

    In an effort to get a better understanding of the extent and patterns of burning in South America, geostationary satellite data have been used to monitor active fires. Previous work demonstrated the ability to manually detect subpixel fire activity in selected areas of the selva and cerrado regions in South America with shortwave and longwave infrared data available from the Geostationary Operational Environmental Satellite (GOES) visible infrared spin scan radiometer atmospheric sounder (VAS) This paper presents the GOES VAS automated biomass-burning algorithm (ABBA) which was developed to determine basin-wide trends in fire activity in South America utilizing the GOES VAS archive. Comparisons between the manual and the automated techniques revealed that overall, the ABBA proved to be more consistent in identifying fires and better suited for trend analysis. The automated algorithm was applied daily to a study area extending from 5°S to 15°S and from 45°W to 70°W for 2 weeks at the peak of the burning seasons in South America in 1983, 1988, 1989, and 1991 in an effort to measure the areal extent of burning in South America during the past decade and to provide additional insight into the diurnal signature in satellite detection of biomass-burning activities. The expansion of the regions of burning are readily detected in a comparison of these 4 years. From 1983 to 1991 the amount of burning detected by the GOES VAS ABBA during these 2-week periods nearly doubled in the selva and mixed regions and tripled in the cerrado. Diurnal analyses confirmed earlier results indicating that the optimum time to monitor biomass burning is around 1530 UTC.

  18. Impact of Measurement System Characteristics on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Liu, Xu; Zhou, Daniel K.

    2011-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such an improvement in geophysical information inferred from these observations requires optimal usage of data from current systems as well as instrument system enhancements for future sensors. This presentation addresses results of tradeoff studies evaluating the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species information obtainable from advanced atmospheric sounders. Particular attention will be devoted toward information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument to fly aboard the NPP and JPSS series of satellites expected to begin in late 2011. While all of these systems cover nearly the same infrared spectral extent, they have very different number of channels, instrument line shapes, coverage continuity, and instrument noise. AIRS is a grating spectrometer having 2378 discrete spectral channels ranging from about 0.4 to 2.2/cm resolution; IASI is a Michelson interferometer with 8461 uniformly-spaced spectral channels of 0.5/cm (apodized) resolution; and CrIS is a Michelson interferometer having 1305 spectral channels of 0.625, 1.250, and 2.50/cm (unapodized) spectral resolution, respectively, over its three continuous but non-overlapping bands. Results of tradeoff studies showing information content sensitivity to assumed measurement system characteristics will be presented.

  19. Performance Expectations for Future Moderate Resolution Visible and Infrared Space Instruments Based on AIRS and MODIS In-Flight Experience

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Broberg, Steven E.; Aumann, Hartmut H.; Baron, Richard L.

    2004-01-01

    Lessons learned from the Atmospheric Infrared Sounder (AIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) projects highlight areas where further technology development is needed to address future land, ocean and atmospheric measurement needs. Although not established as requirements at this time, it is anticipated that scientists will expect improvements in the areas of spatial, spectral, radiometric, polarimetric, temporal and calibration performance for future sensors. This paper addresses each of these performance areas and provides lessons learned from MODIS and AIRS. We also present expectations in performance of the system based on information from NASA Instrument Incubator Program and industry reports. Tradeoffs are presented vs orbit altitude (LEO, ME0 and GEO) and provide a 'systems' perspective to future measurement concepts.

  20. Infrared Photography as an Air Pollution Surveillance Instrument

    ERIC Educational Resources Information Center

    Casalinuovo, Anthony F.; Sawan, Alan

    1976-01-01

    The purpose of this study was to determine the practicality of infrared photographic analysis to air pollution agencies, by the detection of plant damage from pollutants before they are visually identifiable. Results showed that photomicrographic imaging using infrared radiation should be considered a viable surveillance tool in similiar…

  1. Verification of mesoscale objective analyses of VAS and rawinsode data using the March 1982 AVE/VAS special network data. [Atmospheric Variability Experiment/Visible-infrared spin-scan radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Doyle, James D.; Warner, Thomas T.

    1988-01-01

    Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) Procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed.

  2. [Analysis of the Influence of Temperature on the Retrieval of Ozone Vertical Profiles Using the Thermal Infrared CrIS Sounder].

    PubMed

    Ma, Peng-fei; Chen, Liang-fu; Zou, Ming-min; Zhang, Ying; Tao, Ming-hui; Wang, Zi-leng; Su, Lin

    2015-12-01

    Ozone is a particularly critical trace gas in the Earth's atmosphere, since this molecule plays a key role in the photochemical reactions and climate change. The TIR measurements can capture the variability of ozone and are weakly sensitive to the lowermost tropospheric ozone content but can provide accurate measurements of tropospheric ozone and higher vertical resolution ozone profiles, with the additional advantage that measurements are also possible during the night. Because of the influence of atmospheric temperature, the ozone profile retrieval accuracy is severely limited. This paper analyze and discuss the ozone absorption spectra and weighting function sensitivity of temperature and its influence on ozone profile retrieval in detail. First, we simulate the change of atmospheric transmittance and radiance by importing 1 K temperature uncertainty, using line-by-line radiative transfer mode under 6 different atmosphere modes. The results show that the transmittance change ratio for 1 K temperature variation was consistent with the transmittance change ratio for 5%-6% change of ozone density variation in all layers of the profile. Then, we calculate the change of weighting function by a temperature error of 1 K, using the Community Radiative Transfer Model (CRTM) for the Cross-track Infrared Sounder (CrIS) on the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite and calculate the corresponding change of retrieval result. The results demonstrate that CrIS is sensitive to Ozone in the middle to upper stratosphere, with the peak vertical sensitivity between 10-100 hPa and the change of weighting function for 1 K temperature variation was consistent with 6% change in the ozone profile. Finally, the paper retrieves ozone profiles from the CrIS radiances with a nonlinear Newton iteration method and use the eigenvector regression algorithm to construct the a priori state. In order to resolve the problem of temperature uncertainty and get high accuracy

  3. AIRES: An Airborne Infra-Red Echelle Spectrometer for SOFIA

    NASA Technical Reports Server (NTRS)

    Dotson, Jessie J.; Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Telesco, Charles M.; Pina, Robert K.; Wolf, Juergen; Young, Erick T.

    1999-01-01

    SOFIA will enable astronomical observations with unprecedented angular resolution at infrared wavelengths obscured from the ground. To help open this new chapter in the exploration of the infrared universe, we are building AIRES, an Airborne Infra-Red Echelle Spectrometer. AIRES will be operated as a first generation, general purpose facility instrument by USRA, NASA's prime contractor for SOFIA. AIRES is a long slit spectrograph operating from 17 - 210 microns. In high resolution mode the spectral resolving power is approx. 10(exp 6) microns/A or approx. 10(exp 4) at 100 microns. Unfortunately, since the conference, a low resolution mode with resolving power about 100 times lower has been deleted due to budgetary constraints. AIRES includes a slit viewing camera which operates in broad bands at 18 and 25 microns.

  4. REMOTE FOURIER TRANSFORM INFRARED AIR POLLUTION STUDIES

    EPA Science Inventory

    A commercial Fourier transform infrared interferometer system has been installed in a van and used to make longpath absorption and single-ended emission measurements of gaseous pollutant concentrations at a variety of pollutant sources. The interferometer system is described and ...

  5. Infrared Signature Masking by Air Plasma Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, C. H.; Laux, C. O.

    1998-01-01

    Detailed measurements and modeling of the spectral emission of an atmospheric pressure air plasma at temperatures up to -3400 K have been made. The cold gas injected in the plasma torch contained an estimated mole fraction of water vapor of approximately 4.5 x 10(exp -3) and an estimated carbon dioxide mole fraction of approximately 3.3 x 10(exp -4). Under these conditions, the minimum level of air plasma emission is found to be between 3.9 and 4.15 microns. Outside this narrow region, significant spectral emission is detected that can be attributed to the fundamental and overtone bands of NO and OH, and to the v(sub 3) and the (v(sub 1)+v(sub 3)) bands Of CO2. Special attention was paid to the effects of ambient air absorption in the optical path between the plasma and the detector. Excellent quantitative agreement is obtained between the measured and simulated spectra, which are both on absolute intensity scales, thus lending confidence in the radiation models incorporated into NEQAIR2-IR over the course of this research program.

  6. Infrared propagation in the air-sea boundary layer

    NASA Astrophysics Data System (ADS)

    Larsen, R.; Preedy, K. A.; Drake, G.

    1990-03-01

    Over the oceans and other large bodies of water the structure of the lowest layers of the atmosphere is often strongly modified by evaporation of water vapor from the water surface. At radio wavelengths this layer will usually be strongly refracting or ducting, and the layer is commonly known as the evaporation duct. However, the refractive index of air at infrared wavelengths differs from that at radio wavelengths, and the effects of the marine boundary layer on the propagation of infrared radiation are examined. Meteorological models of the air-sea boundary layer are used to compute vertical profiles of temperature and water-vapor pressure. From these are derived profiles of atmospheric refractive index at radio wavelengths and at infrared wavelengths in the window regions of low absorption. For duct propagation to occur it is necessary that the refractivity of air decreases rapidly with increasing height above the surface. At radio wavelengths this usually occurs when there is a strong lapse of water vapor pressure with increasing height. By contrast, at infrared wavelengths the refractive index is almost independent of water vapor pressure, and it is found that an infrared duct is formed only when there is a temperature inversion.

  7. Investigation of Infra-red and Nonequilibrium Air Radiation

    NASA Technical Reports Server (NTRS)

    Kruger, Charles H.; Laux, Christophe O.

    1994-01-01

    This report summarizes the results obtained during a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University. This program was intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. Prior to this work, the radiative emission of air plasmas in the infrared had been the object of few experimental investigations, and although several infrared systems were already modeled in radiation codes such as NEQAIR, measurements were required to validate numerical predictions and indicate whether all transitions of importance were accounted for in the model. The program was further motivated by the fact that 9 excited states (A, B, C, D, B', F, H, and H') of NO radiate in the infrared, especially between 1 and 1.5 microns where at least 9 transitions involving can be observed. Because these IR transitions are relatively well separated from each other, excited NO states concentrations can be easily measured, thus providing essential information on excited-state chemistry for use in optical diagnostics or in electronic excitation model validation. Detailed comparisons between measured and simulated spectra are presented.

  8. Infrared Signatures of Laser Induced Plasma in Air

    NASA Astrophysics Data System (ADS)

    Hening, Alexandru; Lu, Ryan; Ramirez, Ayax; Advanced Technology Team

    2014-03-01

    Characterization of the temporal and spatial evolution of laser generated plasma in air is necessary for the development of potential applications which range from laser induced ionized micro channels and filaments able to transfer high electric pulses over few hundreds of meters, to the generation of plasma artifacts in air, far away from the laser source. This work is focused mainly on the infrared spectrum. The influence of laser parameters (energy per pulse, pulse duration, repetition rate, wavelength and etc.) on the plasma formation and evolution has been investigated. Laser transmission losses through the air as well as through the breakdown plasma as well as their effect on infrared plasma signature are to be presented.

  9. Technology Development for a Hyperspectral Microwave Atmospheric Sounder (HyMAS)

    NASA Technical Reports Server (NTRS)

    Blackwell, W.; Galbraith, C.; Hilliard, L.; Racette, P.; Thompson, E.

    2014-01-01

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term hyperspectral microwave is used to indicate an all-weather sounding instrument that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earths atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions.

  10. Variational assimilation of VAS data into a mesoscale model Assimilation method and sensitivity experiments. [Visible Infrared Spin-Scan Radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Cram, J. M.; Kaplan, M. L.

    1985-01-01

    The assimilation of temperature and moisture gradient information from the Visible IR Spin-Scan Radiometer's Atmospheric Sounder (VAS) into a mesoscale model is presently undertaken by means of a variational method and followed by tests of the sensitivity of both diabatic and adiabatic versions of the model to VAS data assimilations for the case of July 20-21, 1981. The synoptic scale effects of the assimilation of VAS data are noted to be negligible; the greatest impact was instead on mesoscale forecasts of convective instability patterns. The additional assimilation of relative humidity gradients did not significantly change the patterns of the forecast instabilities. The greatest improvements from assimilation resulted from the resolution of the strong mesoscale temperature gradients by the asynoptic VAS data.

  11. Hurricane Debby - An illustration of the complementary nature of VAS soundings and cloud and water vapor motion winds. [Visible Infrared Spin Scan Radiometer Atmospheric Sounder

    NASA Technical Reports Server (NTRS)

    Le Marshall, J. F.; Smith, W. L.; Callan, G. M.

    1985-01-01

    The utility of VISSR Atmospheric Sounder (VAS) temperature and moisture soundings and cloud and water vapor motion winds in defining a storm and its surroundings at subsynoptic scales has been examined using a numerical analysis and prognosis system. It is shown that the VAS temperature and moisture data, which specify temperature and moisture well in cloud-free areas, are complemented by cloud and water vapor motion data generated in the cloudy areas. The cloud and water vapor 'winds' provide thermal gradient information for interpolating the soundings across cloudy regions. The loss of analysis integrity due to the reduction of VAS sounding density in the cloudy regions associated with synoptic activity is ameliorated by using cloud and water vapor motion winds. The improvement in numerical forecasts resulting from the addition of these data to the numerical analysis is recorded.

  12. Infrared Laser System for Extended Area Monitoring of Air Pollution

    NASA Technical Reports Server (NTRS)

    Snowman, L. R.; Gillmeister, R. J.

    1971-01-01

    An atmospheric pollution monitoring system using a spectrally scanning laser has been developed by the General Electric Company. This paper will report on an evaluation of a breadboard model, and will discuss applications of the concept to various ambient air monitoring situations. The system is adaptable to other tunable lasers. Operating in the middle infrared region, the system uses retroreflectors to measure average concentrations over long paths at low, safe power levels. The concept shows promise of meeting operational needs in ambient air monitoring and providing new data for atmospheric research.

  13. How Strong is the Case for Geostationary Hyperspectral Sounders?

    NASA Astrophysics Data System (ADS)

    Kirk-Davidoff, D. B.; Liu, Z.; Jensen, S.; Housley, E.

    2014-12-01

    The NASA GIFTS program designed and constructed a flight-ready hyperspectral infrared sounder for geostationary orbit. Efforts are now underway to launch a constellation of similar instruments. Salient characteristics included 4 km spatial resolution at nadir and 0.6 cm-1 spectral resolution in two infrared bands. Observing system experiments have demonstrated the success of assimilated hyperspectral infrared radiances from IASI and AIRS in improving weather forecast skill. These results provide circumstantial evidence that additional observations at higher spatial and temporal resolution would likely improve forecast skill further. However, there is only limited work investigating the magnitude of this skill improvement in the literature. Here we present a systematic program to quantify the additional skill of a constellation of geostationary hyperspectral sounders through observing system simulation experiments (OSSEs) using the WRF model and the WRFDA data assimilation system. The OSSEs will focus first on high-impact events, such as the forecast for Typhoon Haiyun, but will also address quotidian synoptic forecast skill. The focus will be on short-term forecast skill (<24 hours lead time), in accord with WRF's mesoscale design, and with the view that high time frequency observations are likely to make the biggest impact on the skill of short-range forecasts. The experiments will use as their starting point the full existing observational suite, so that additionality can be addressed, but will also consider contingencies, such as the loss of particular elements of the existing system, as well as the degree to which a stand-alone system of hyperspectral sounds would be able to successfully initialize a regional forecast model. A variety of settings, tropical and extratropical, marine and continental will be considered.

  14. Investigation of infra-red and nonequilibrium air radiation

    NASA Technical Reports Server (NTRS)

    Kruger, Charles H.

    1995-01-01

    This report describes progress on the first year of a research program on the infrared radiation of air plasmas conducted in the High Temperature Gasdynamics Laboratory at Stanford University. This program is intended to investigate the masking of infrared signatures by the air plasma formed behind the bow shock of high velocity missiles. To this date, the radiative emission of air plasmas in the infrared has been the object of few experimental investigations, and although several infrared systems are already modeled in radiation codes such as NEQAIR, measurements are required to validate numerical predictions and indicate whether all transitions of importance are accounted for. The present program is motivated by the fact that 9 excited states (A, B, C, D, B', F, H, and H') of NO radiate in the infrared, especially between 1 and 1.5 microns where at least 9 transitions involving can be observed. Because these IR transitions are relatively well separated from each other, excited NO states concentrations can be easily measured, thus providing essential information on excited-state chemistry for use in optical diagnostics or in electronic excitation model validation. Developing accurate collisional-radiative models for these excited NO states is of importance as the UV-VUV transitions of NO (beta, gamma, epsilon, beta prime, gamma prime) produce a major, if not dominant, fraction of the radiation emitted by air plasmas. During the first year of the program, research has focused on the spectral range 1.0 to 1.5 microns, as detailed in Section 2 of this report. The measurements, conducted in a 50 kW radio-frequency inductively coupled plasma torch operating on air at atmospheric pressure, extend previous shock tube investigations by Wray to a wider spectral range (1.0 to 1.5 microns vs 0.9 to 1.2 microns) and higher temperatures (7600 K in the plasma torch versus 6700 K in the shock-tube). These higher temperatures in the present experiment have made it possible to

  15. AIRS PFM Pulse Tube Cooler System-level Performance

    NASA Technical Reports Server (NTRS)

    Ross, R.; Johnson, D.; Collins, S.; Green, K.; Wickman, H.

    1998-01-01

    JPL's Atmospheric Infrared Sounder (AIRS) instrument is being built to make precision measurements of air temperature over the surface of the Earth as a function of elevation; the flight instrument is in the final stages of assembly and checkout at this time, and uses a pair of TRW pulse tube cryocoolers operating at 55K to cool its sensitive IR focal plane.

  16. Cloud and Thermodynamic Parameters Retrieved from Satellite Ultraspectral Infrared Measurements

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Smith, William L.; Larar, Allen M.; Liu, Xu; Taylor, Jonathan P.; Schluessel, Peter; Strow, L. Larrabee; Mango, Stephen A.

    2008-01-01

    Atmospheric-thermodynamic parameters and surface properties are basic meteorological parameters for weather forecasting. A physical geophysical parameter retrieval scheme dealing with cloudy and cloud-free radiance observed with satellite ultraspectral infrared sounders has been developed and applied to the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric InfraRed Sounder (AIRS). The retrieved parameters presented herein are from radiance data gathered during the Joint Airborne IASI Validation Experiment (JAIVEx). JAIVEx provided intensive aircraft observations obtained from airborne Fourier Transform Spectrometer (FTS) systems, in-situ measurements, and dedicated dropsonde and radiosonde measurements for the validation of the IASI products. Here, IASI atmospheric profile retrievals are compared with those obtained from dedicated dropsondes, radiosondes, and the airborne FTS system. The IASI examples presented here demonstrate the ability to retrieve fine-scale horizontal features with high vertical resolution from satellite ultraspectral sounder radiance spectra.

  17. Apollo lunar sounder experiment

    USGS Publications Warehouse

    Phillips, R.J.; Adams, G.F.; Brown, W.E., Jr.; Eggleton, R.E.; Jackson, P.; Jordan, R.; Linlor, W.I.; Peeples, W.J.; Porcello, L.J.; Ryu, J.; Schaber, G.; Sill, W.R.; Thompson, T.W.; Ward, S.H.; Zelenka, J.S.

    1973-01-01

    The scientific objectives of the Apollo lunar sounder experiment (ALSE) are (1) mapping of subsurface electrical conductivity structure to infer geological structure, (2) surface profiling to determine lunar topographic variations, (3) surface imaging, and (4) measuring galactic electromagnetic radiation in the lunar environment. The ALSE was a three-frequency, wide-band, coherent radar system operated from lunar orbit during the Apollo 17 mission.

  18. PREMIER's imaging IR limb sounder

    NASA Astrophysics Data System (ADS)

    Kraft, Stefan; Caron, Jerome; Bézy, Jean-Loup; Meynart, Roland; Langen, Jörg; Carnicero Dominguez, Bernardo; Bensi, Paolo; Silvestrin, Pierluigi

    2011-11-01

    The Imaging IR Limb Sounder (IRLS) is one of the two instruments planned on board of the candidate Earth Explorer Core Mission PREMIER. PREMIER stands for PRocess Exploration through Measurements of Infrared and Millimetrewave Emitted Radiation and is presently under feasibility study by ESA. Emerging from recent enhanced detector and processing technologies IRLS shall, next to a millimetre-wave limb sounder, explore the benefits of three-dimensional limb sounding with embedded cloud imaging capability. Such 3d imaging technology is expected to open a new era of limb sounding that will allow detailed studies of the link between atmospheric composition and climate, since it will map simultaneously fields of temperature and many trace gases in the mid/upper troposphere and stratosphere across a large vertical and horizontal field of view and with relatively high vertical and horizontal resolution. PREMIER shall fly in tandem formation looking backwards to METOP's swath and thereby explore the benefit of 3-dimensional information for meteorological/environmental analyses and climate forcing investigations. As currently planned and if implemented, IRLS will cover a total horizontal field of about 360 km and observe the limb at altitudes between 4 and 52 km. The vertical spatial sampling distance (SSD) will be well below 1 km. It will be run in two different exclusive modes to address scientific questions about atmospheric dynamics and chemistry at spectral samplings of ~1.2 cm-1 and ~0.2 cm-1, respectively. In such configuration IRLS will be composed of an imaging array with about 1800 macro pixels or sub-samples, thereby allowing cloud imaging and rejection at sufficient spatial resolution. We will present an overview of the instrument requirements as derived from the scientific requirements, the present status of the mission, and we will give an overview of the currently identified technology needs and instrument predevelopments.

  19. Community Radiative Transfer Model Applications - A Study of the Retrieval of Trace Gases in the Atmosphere from Cross-track Infrared Sounder (CrIS) Data of a Full-spectral Resolution

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Nalli, N. R.; Tan, C.; Zhang, K.; Iturbide, F.; Wilson, M.; Zhou, L.

    2015-12-01

    The Community Radiative Transfer Model (CRTM) [3] operationally supports satellite radiance assimilation for weather forecasting, sensor data verification, and the retrievals of satellite products. The CRTM has been applied to UV and visible sensors, infrared and microwave sensors. The paper will demonstrate the applications of the CRTM, in particular radiative transfer in the retrieva algorithm. The NOAA Unique CrIS/ATMS Processing System (NUCAPS) operationally generates vertical profiles of atmospheric temperature (AVTP) and moisture (AVMP) from Suomi NPP Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) measurements. Current operational CrIS data have reduced spectral resolution: 1.25 cm-1 for a middle wave band and 2.5 cm-1 for a short-wave wave band [1]. The reduced spectral data largely degraded the retrieval accuracy of trace gases. CrIS full spectral data are also available now which have single spectral resolution of 0.625 cm-1 for all of the three bands: long-wave band, middle wave band, and short-wave band. The CrIS full-spectral resolution data is critical to the retrieval of trace gases such as O3, CO [2], CO2, and CH4. In this paper, we use the Community Radiative Transfer Model (CRTM) to study the impact of the CrIS spectral resolution on the retrieval accuracy of trace gases. The newly released CRTM version 2.2.1 can simulates Hamming-apodized CrIS radiance of a full-spectral resolution. We developed a small utility that can convert the CRTM simulated radiance to un-apodized radiance. The latter has better spectral information which can be helpful to the retrievals of the trace gases. The retrievals will be validated using both NWP model data as well as the data collected during AEROSE expeditions [4]. We will also discuss the sensitivity on trace gases between apodized and un-apodized radiances. References[1] Gambacorta, A., et al.(2013), IEEE Lett., 11(9), doi:10.1109/LGRS.2014.230364, 1639-1643. [2] Han, Y., et

  20. Sensor System Performance Evaluation and Benefits from the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I)

    NASA Technical Reports Server (NTRS)

    Larar, A.; Zhou, D.; Smith, W.

    2009-01-01

    Advanced satellite sensors are tasked with improving global-scale measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring, and environmental change detection. Validation of the entire measurement system is crucial to achieving this goal and thus maximizing research and operational utility of resultant data. Field campaigns employing satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft are an essential part of this validation task. The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) has been a fundamental contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This paper focuses on some of the challenges associated with validating advanced atmospheric sounders and the benefits obtained from employing airborne interferometers such as the NAST-I. Select results from underflights of the Aqua Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) obtained during recent field campaigns will be presented.

  1. AIRS CO2 Retrievals Using the Method of Vanishing Partial Derivatives (VPD)

    NASA Technical Reports Server (NTRS)

    Chahine, Moustafa; Yung, Yuk; Li, Qinbin; Olsen, Ed; Chen, Luke; Krakauer, Nir

    2006-01-01

    This document consists of presentation slides that review the work being done with observations from the Atmospheric Infrared Sounder (AIRS) using the concept of Vanishing Partial Derivatives. The infrared region is where several minor gases such as CO2, O3, CO, CH4 and SO2 are radiatively active.

  2. Spectral Resolution and Coverage Impact on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Liu, Xu; Zhou, Daniel K.; Smith, William L.

    2010-01-01

    Advanced satellite sensors are tasked with improving global measurements of the Earth s atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such measurement improvements requires instrument system advancements. This presentation focuses on the impact of spectral resolution and coverage changes on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species variables obtainable from advanced atmospheric sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and Cross-track Infrared Sounder (CrIS) systems on the MetOp and NPP/NPOESS series of satellites. Key words: remote sensing, advanced sounders, information content, IASI, CrIS

  3. Fuzzy clustering of infrared images applied in air leak localization

    NASA Astrophysics Data System (ADS)

    Ge, Nan; Peng, Guang-zheng; Jiang, Mu-zhou

    2009-07-01

    Most current research into the localization of leaks is focused on leaks of petroleum and natural gas pipelines, while there is very little new work being done on the leakage of vessels. A novel air-leak diagnosis and localization method based on infrared thermography is described in this paper, which is developed in an attempt to overcome the disadvantages of low efficiency and poor anti-jamming ability associated with the traditional approaches to localization of leaks from a vessel. The method achieves leak positioning through a factor θ based kernelized fuzzy clustering segmentation done to weighted differential thermal images of the test objects. The temperature difference factor θ is inventively built as a parameter changed with temperature range of the target region, in order to enhance the robustness and the interference proof ability of the algorithm. Heat transfer simulation with air-leak flow is addressed by the finite element analysis. The experimental results indicate that the method proposed is effective and sensitive. The purpose of air-leak localization has been reached.

  4. New generation topside sounder

    NASA Astrophysics Data System (ADS)

    Ganguly, Suman; Wickwar, Vincent; Goodman, John M.

    2001-09-01

    Having ionospheric electron density distributions as a function of height, latitude, longitude, and time under different conditions is essential for scientific, technical, and operational purposes. A satellite-based, swept-frequency, HF sounder can obtain electron density profiles on a global scale. We are developing a new generation HF sounder that employs recent developments in technology, electronics, and processing capabilities. It will provide global-scale electron density distributions, contours of fixed densities, maps of ƒoF2, hmax, etc. It will allow us to map irregularities, estimate anomalous propagation and conditions for ducting, determine angles of arrival, etc. It will also be able to perform various plasma diagnostics and, because of new flexibility, will be programmable from the ground to perform a variety of experiments in space. Need for such a system exists through the Department of Defense and several civilian agencies. Some of the novel features of the system include software-based design, direction of arrival estimation and synthetic aperture radar-type operation, onboard processing, and reconfigurable and flexible architecture with multimission capabilities.

  5. A Microwave Pressure Sounder

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    An instrument to measure atmospheric pressure at the earth's surface from an orbiting satellite would be a valuable addition to the expanding inventory of remote sensors. The subject of this report is such an instrument - the Microwave Pressure Sounder (MPS). It is shown that global-ocean coverage is attainable with sufficient accuracy, resolution and observational frequency for meteorological, oceanographic and climate research applications. Surface pressure can be deduced from a measurement of the absorption by an atmospheric column at a frequency in the wing of the oxygen band centered on 60 GHz. An active multifrequency instrument is needed to make this measurement with sufficient accuracy. The selection of optimum operating frequencies is based upon accepted models of surface reflection, oxygen, water vapor and cloud absorption. Numerical simulation using a range of real atmospheres defined by radiosonde observations were used to validate the frequency selection procedure. Analyses are presented of alternative system configurations that define the balance between accuracy and achievable resolution.

  6. Lessons Learned from AIRS: Improved Determination of Surface and Atmospheric Temperatures Using Only Shortwave AIRS Channels

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2011-01-01

    This slide presentation reviews the use of shortwave channels available to the Atmospheric Infrared Sounder (AIRS) to improve the determination of surface and atmospheric temperatures. The AIRS instrument is compared with the Infrared Atmospheric Sounding Interferometer (IASI) on-board the MetOp-A satellite. The objectives of the AIRS/AMSU were to (1) provide real time observations to improve numerical weather prediction via data assimilation, (2) Provide observations to measure and explain interannual variability and trends and (3) Use of AIRS product error estimates allows for QC optimized for each application. Successive versions in the AIRS retrieval methodology have shown significant improvement.

  7. Characteristics of Monsoon inversions over Arabian Sea observed by satellite sounder and reanalysis data sets

    NASA Astrophysics Data System (ADS)

    Dwivedi, Sanjeev; Narayanan, M. S.; Venkat Ratnam, M.; Narayana Rao, D.

    2015-12-01

    Monsoon inversions (MIs) over Arabian Sea (AS) are an important characteristic associated with the monsoon activity over Indian region during summer monsoon season. In the present study, we have used five years (2009-2013) data of temperature and water vapor profiles obtained from satellite sounder instrument, Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp satellite, besides ERA-Interim data, to study their characteristics. The lower atmospheric data over the AS have been examined first to identify the areas where monsoon inversions are predominant and occur with higher strength. Based on this information, a detailed study has been made to investigate their characteristics separately in eastern AS (EAS) and western AS (WAS) to examine their contrasting features. The initiation and dissipation times of MI, their percentage occurrence, strength etc., has been examined using the huge data base. The relation with monsoon activity (rainfall) over Indian region during normal and poor monsoon years is also studied. WAS ΔT values are ~ 2 K less than those over the EAS, ΔT being temperature difference between 950 and 850 hPa. A much larger contrast between WAS and EAS in ΔT is noticed in ERA-Interim dataset Vis a Vis those observed by satellites. The possibility of detecting MI from another parameter, Refractivity N, obtained directly from another satellite constellation of GPS RO (COSMIC), has also been examined. MI detected from IASI and Atmospheric InfraRed Sounder (AIRS) sounder onboard NOAA satellite have been compared to see how far the two data sets can be combined to study the MI characteristics. We suggest MI could also be included as one of the semi-permanent features of southwest monsoon along with the presently accepted six parameters.

  8. Requirements for an Advanced Low Earth Orbit (LEO) Sounder (ALS) for improved regional weather prediction and monitoring of greenhouse gases

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Susskind, Joel

    2008-12-01

    Hyperspectral infrared atmospheric sounders (e.g. the Atmospheric Infrared Sounder (AIRS) on Aqua and the Infrared Atmospheric Sounding Interferometer (IASI) on MetOp) provide highly accurate temperature and water vapor profiles in the lower to upper troposphere. These systems are vital operational components of our National Weather Prediction system and the AIRS has demonstrated over 6 hrs of forecast improvement on the 5 day operational forecast1. Despite the success in the mid troposphere to lower stratosphere, a reduction in sensitivity and accuracy has been seen in these systems in the boundary layer over land. In this paper we demonstrate the potential improvement associated with higher spatial resolution (1km vs currently 13.5 km) on the accuracy of boundary layer products with an added consequence of higher yield of cloud free scenes. This latter feature is related to the number of samples that can be assimilated and has also shown to have a significant impact on improving forecast accuracy. We also present a set of frequencies and resolutions that will improve vertical resolution of temperature and water vapor and trace gas species throughout the atmosphere. Development of an Advanced Low Earth Orbit (LEO) Sounder (ALS) with these improvements will improve weather forecast at the regional scale and of tropical storms and hurricanes. Improvements are also expected in the accuracy of the water vapor and cloud properties products, enhancing process studies and providing a better match to the resolution of future climate models. The improvements of technology required for the ALS are consistent with the current state of technology as demonstrated in NASA Instrument Incubator Program and NOAA's Hyperspectral Environmental Suite (HES) formulation phase development programs.

  9. Requirements for an Advanced Low Earth Orbit (LEO) Sounder (ALS) for Improved Regional Weather Prediction and Monitoring of Greenhouse Gases

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Susskind, Joel

    2008-01-01

    Hyperspectral infrared atmospheric sounders (e.g., the Atmospheric Infrared Sounder (AIRS) on Aqua and the Infrared Atmospheric Sounding Interferometer (IASI) on Met Op) provide highly accurate temperature and water vapor profiles in the lower to upper troposphere. These systems are vital operational components of our National Weather Prediction system and the AIRS has demonstrated over 6 hrs of forecast improvement on the 5 day operational forecast. Despite the success in the mid troposphere to lower stratosphere, a reduction in sensitivity and accuracy has been seen in these systems in the boundary layer over land. In this paper we demonstrate the potential improvement associated with higher spatial resolution (1 km vs currently 13.5 km) on the accuracy of boundary layer products with an added consequence of higher yield of cloud free scenes. This latter feature is related to the number of samples that can be assimilated and has also shown to have a significant impact on improving forecast accuracy. We also present a set of frequencies and resolutions that will improve vertical resolution of temperature and water vapor and trace gas species throughout the atmosphere. Development of an Advanced Low Earth Orbit (LEO) Sounder (ALS) with these improvements will improve weather forecast at the regional scale and of tropical storms and hurricanes. Improvements are also expected in the accuracy of the water vapor and cloud properties products, enhancing process studies and providing a better match to the resolution of future climate models. The improvements of technology required for the ALS are consistent with the current state of technology as demonstrated in NASA Instrument Incubator Program and NOAA's Hyperspectral Environmental Suite (HES) formulation phase development programs.

  10. The Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Brendt. Emily; Zavodsky, Bradley; Jedlovec, Gary; Elmer, Nicholas

    2014-01-01

    Tropopause folds are identified by warm, dry, high-potential vorticity, ozone-rich air and are one explanation for damaging non-convective wind events. Could improved model representation of stratospheric air and associated tropopause folding improve non-convective wind forecasts and high wind warnings? The goal of this study is to assess the impact of assimilating Hyperspectral Infrared (IR) profiles on forecasting stratospheric air, tropopause folds, and associated non-convective winds: (1) AIRS: Atmospheric Infrared Sounder (2) IASI: Infrared Atmospheric Sounding Interferometer (3) CrIMSS: Cross-track Infrared and Microwave Sounding Suite

  11. GAS CHROMATOGRAPHY/MATRIX ISOLATION - INFRARED SPECTROMETRY FOR AIR SAMPLE ANALYSIS

    EPA Science Inventory

    This report describes the application of gas chromatography/matrix- solation infrared (GC/MI-IR) spectrometry to the analysIs of environmental air sample extracts. Samples that were analyzed include extracts from woodsmoke-impacted air, XAD-2 blanks, indoor air, and carpet sample...

  12. Neural network temperature and moisture retrieval algorithm validation for AIRS/AMSU and CrIS/ATMS

    NASA Astrophysics Data System (ADS)

    Milstein, Adam B.; Blackwell, William J.

    2016-02-01

    We present comprehensive validation results for the recently introduced neural network technique for retrieving vertical profiles of atmospheric temperature and water vapor from spaceborne microwave and hyperspectral infrared sounding instruments. This technique is currently in operational use as the first guess for the NASA Atmospheric Infrared Sounder (AIRS) Science Team Version 6 retrieval algorithm. The validation incorporates a variety of data sources, independent from the algorithm training set, as ground truth, including global numerical weather analyses generated by the European Center for Medium-Range Weather Forecasts, synoptic radiosonde measurements, and radiosondes dedicated for validation. The results demonstrate significant performance improvements over the previous AIRS/advanced microwave sounding unit (AMSU) operational sounding retrievals in both retrieval error and also show comparable vertical resolution. We also present initial neural network retrieval results using measurements from the Cross-Track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) currently flying on the Suomi National Polar-orbiting Partnership satellite.

  13. First Data from Mars Climate Sounder

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The Mars Climate Sounder, an instrument on NASA's Mars Reconnaissance Orbiter designed to monitor daily changes in the global atmosphere of Mars, made its first observations of Mars on March 24, 2006.

    These tests were conducted to demonstrate that the instrument could, if needed, support the mission's aerobraking maneuvers (dips into the atmosphere to change the shape of the orbit) by providing hemisphere-scale coverage of atmospheric activity. The instrument scanned nine arrays of detectors four times across the entire disc of the planet, including the north pole, from an altitude of about 45,000 kilometers (28,000 miles). This is about 150 times farther away than the spacecraft will be during its main science phase. At this great range, the planet appears only 40 pixels wide, as suggested by the pixilation of the images. However, this is sufficient to identify regional dust storms in the lower atmosphere. Regional dust storms could perturb atmospheric densities at the higher altitudes (about 100 kilometers or 60 miles) where the orbiter will conduct more than 500 aerobraking passes during the next six months. Such storms are rare in the current season on Mars, early northern spring, and no large storms are present as the orbiter prepares for the start of aerobraking.

    Each of the Mars Climate Sounder's arrays looks in a different wavelength band, and three of the resulting images are shown here. The view on the left is from data collected in a broad spectral band (wavelengths of 0.3 microns to 3 microns) for reflected sunlight. The view in the center is from data collected in the 12-micron thermal-infrared band. This band was chosen to sense infrared radiation from the surface when the atmosphere is clear and from dust clouds when it is not. The view on the right is from data collected at 15 microns, a longer-wavelength band still in the thermal-infrared part of the spectrum. At this wavelength, carbon dioxide, the main ingredient in Mars

  14. Regional Data Assimilation of AIRS Profiles and Radiances at the SPoRT Center

    NASA Technical Reports Server (NTRS)

    Zavodsky, Brad; Chou, Shih-hung; Jedlovec, Gary

    2009-01-01

    This slide presentation reviews the Short Term Prediction Research and Transition (SPoRT) Center's mission to improve short-term weather prediction at the regional and local scale. It includes information on the cold bias in Weather Research and Forcasting (WRF), troposphere recordings from the Atmospheric Infrared Sounder (AIRS), and vertical resolution of analysis grid.

  15. Full Spatial Resolution Infrared Sounding Application in the Preconvection Environment

    NASA Astrophysics Data System (ADS)

    Liu, C.; Liu, G.; Lin, T.

    2013-12-01

    Advanced infrared (IR) sounders such as the Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) provide atmospheric temperature and moisture profiles with high vertical resolution and high accuracy in preconvection environments. The derived atmospheric stability indices such as convective available potential energy (CAPE) and lifted index (LI) from advanced IR soundings can provide critical information 1 ; 6 h before the development of severe convective storms. Three convective storms are selected for the evaluation of applying AIRS full spatial resolution soundings and the derived products on providing warning information in the preconvection environments. In the first case, the AIRS full spatial resolution soundings revealed local extremely high atmospheric instability 3 h ahead of the convection on the leading edge of a frontal system, while the second case demonstrates that the extremely high atmospheric instability is associated with the local development of severe thunderstorm in the following hours. The third case is a local severe storm that occurred on 7-8 August 2010 in Zhou Qu, China, which caused more than 1400 deaths and left another 300 or more people missing. The AIRS full spatial resolution LI product shows the atmospheric instability 3.5 h before the storm genesis. The CAPE and LI from AIRS full spatial resolution and operational AIRS/AMSU soundings along with Geostationary Operational Environmental Satellite (GOES) Sounder derived product image (DPI) products were analyzed and compared. Case studies show that full spatial resolution AIRS retrievals provide more useful warning information in the preconvection environments for determining favorable locations for convective initiation (CI) than do the coarser spatial resolution operational soundings and lower spectral resolution GOES Sounder retrievals. The retrieved soundings are also tested in a regional data assimilation WRF 3D-var system to evaluate the

  16. MODTRAN5 analysis of clear-sky, co-located space- and ground-based infrared atmospheric measurements: AERI, AIRS, CERES, MODIS

    NASA Astrophysics Data System (ADS)

    Lewis, Paul E.; Anderson, Gail P.; Shen, Sylvia S.; Chetwynd, James; Roman, Miguel, III; Schaaf, Crystal; Turner, David D.; Rutan, David A.; Berk, Alexander; Miller, David P.; Kroutil, Robert

    2009-05-01

    A set of 26 clear-sky, co-located, infrared data from NASA's space-based, downward looking Atmospheric Infrared Sounder (AIRS)1 and its Clouds and the Earth's Radiant Energy System (CERES)2 have been paired with the DOE's Southern Great Plains (SGP)3 ground-based, upward looking Atmospheric Emitted Radiance Interferometer (AERI)4. These data sets have then been simulated using the MODTRAN®55 (MOD5) radiative transfer code with standard auxiliary 'truth' data as input. Of particular interest is the impact, if any, of the large Ground Sampling Distance (GSD) of AIRS and CERES (minimum radii of approximately 13 and 26 km, respectively) vs. the soda-straw up-looking mode of AERI. The smaller Moderate Resolution Imaging Spectroradiometer (MODIS)6 GSD (<1 km) provides estimated distributions of land-type and albedo within the larger footprints. The SGP's coincident vertical profile sondes and Aeronet7 retrievals, along with other satellite data [Ozone Monitoring Instrument (OMI)8] constrain the surface type, column ozone and aerosol optical depth that existed during the measurement events. Initial MOD5 calculations, using these ancillary data as input, have replicated the AERI and AIRS measurements to within an average difference of ~1% over their entire spectral range. Using MODIS visible albedo9 retrievals to extend the albedo into the long wave (LW) only slightly improved the statistical comparison between the CERES and MOD5 broadband LW radiances agreement, from 3% to ~1.5%, while increasing the variance. While these results are not sufficient for specific instrument inversion algorithms, they suggest some confidence in the generic use of MODTRAN®5 to help integrate and spectrally extend assorted data sets for sensitivity studies of Climate Change, where the estimated required sensitivity is <1%.

  17. AIRS Level 2 Data Products

    NASA Technical Reports Server (NTRS)

    Vicente, Gilberto

    2003-01-01

    The Atmospheric InfraRed Sounder (AIRS) Standard Retrieval Product consists of retrieved cloud and surface properties; profiles of retrieved temperature, water vapor, and ozone; and a flag indicating the presence of cloud ice or water. They contain quality assessment flags in addition to retrieved quantities and are generated for all locations where atmospheric soundings are taken. An AIRS granule consists of 6 minutes of data. This corresponds to approximately 1/15 of an orbit but exactly 45 scan lines of AMSU-A data or 135 scan lines of AIRS and HSB data.

  18. A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)

    NASA Technical Reports Server (NTRS)

    Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.

    1992-01-01

    Until recently, the scarcity of meteorological observations over polar areas has limited studies of high-latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data have been used successfully for delineating synoptic and subsynoptic systems, since they provide the vertical temperature structure of the atmosphere; SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted simultaneous analysis of TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.

  19. A cold air outbreak over the Norwegian Sea observed with the Tiros-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)

    NASA Technical Reports Server (NTRS)

    Claud, Chantal; Katsaros, Kristina B.; Petty, Grant W.; Chedin, Alain; Scott, Noelle A.

    1992-01-01

    Until recently, the scarcity of meteorological observations over polar areas has limited studies of high latitude weather systems, but now data from polar orbiting satellites offer a new opportunity to observe and describe these systems. TOVS data were used successfully for delineating synoptic and subsynoptic systems since they provide the vertical temperature structure of the atmosphere: SSM/I observations have proved valuable for analyzing storms through water vapor and rain determinations. These positive results prompted us to analyze simultaneous TOVS and SSM/I observations obtained during a cold air outbreak over the Norwegian Sea. After a description of the instruments and the retrieval schemes, the mutually supporting information from these two independent instruments is discussed. Implications for the monitoring of polar lows are presented.

  20. AIRS Detection of Dust: Global Map for July 2003

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The averaged brightness temperature differences between the 961 and 1231 cm-1 AIRS channels for July 2003, reveal long range transport of Sahara Dust across the Atlantic.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  1. An Emerging ESDR: Multi-Platform Hyperspectral Infrared Radiances fromEOS-AIRS, S-NPP/JPSS CrIS, and METOP IASI

    NASA Astrophysics Data System (ADS)

    Strow, L. L.; Desouza-Machado, S. G.; Motteler, H.; Hepplewhite, C. L.

    2014-12-01

    Space-based measurements of high-spectral resolution infrared (IR) radiances of the earth began in Sept. 2002 with the NASA EOS-AQUA AIRS instrument. The CrIS instrument on NASA's Suomi-NPP platform supplements this record in the 1:30 polar orbit, starting in 2012, and may continue for 15 years under the NOAA/NASA JPSS Program. The first of three IASI hyperspectral sounders on EUMETSAT's METOP platforms (9:30 orbit) started operation in July 2007, followed by the 2nd IASI on METOP-2 in early 2013. Development of a follow-on instrument (IASI-NG) for post METOP-3 is well underway. These instruments are sensitive to the atmospheric temperature and humidity profile, surface temperature and emissivity, and minor gases (CO2, O3, CO, CH4, N2O, CFCs, HNO3, etc.) They also have high sensitivity to clouds, especially long-wave cloud radiative forcing. The National Research Council has recommended the development of a hyperspectral IR radiance climate data set as a climate benchmark. We present here evidence that supports the use of the existing hyperspectral sounders for generation of these ESDRs and eventually CDRs. The large spatial and temporal overlap between these sensors has provided a rich data-set for inter-calibration studies that are used to characterize the accuracy of a combined ESDR radiance product. We will discuss the stability of each instrument, and inter-calibration differences (with error estimates). In addition, we have developed robust, non-statistical approaches for converting the AIRS spectral radiances into equivalent CrIS radiances, a key step in development of a long-term consistent radiance record. Finally, several examples of robust decadal changes in the earth's atmosphere using AIRS will be discussed and compared to ERA and MERRA re-analysis products (temperature, water vapor, cloud forcing). Finally, we will review the challenges involved in creating an ESDR from 3 different instruments and institutions/countries.

  2. Advanced atmospheric sounder and imaging radiometer /AASIR/ for STORMSAT

    NASA Technical Reports Server (NTRS)

    Chase, S. C.

    1976-01-01

    The principal mission of the three-axis stabilized STORMSAT spacecraft is to provide the necessary meteorological data for tracking, studying the detailed structure, and modeling mesoscale weather phenomena. In the area of mesoscale events, the following meteorological objectives are indicated: high-quality imagery, visible and infrared; wind velocity from cloud tracers (1 m/sec), atmospheric temperature profiles (1 K), and atmospheric humidity sounding. These objectives are reflected in the functional characteristics of the AASIR, which is a second generation meteorological sensor based on the Visible Infrared Spin-Scan Radiometer (VISSR) and the Atmospheric Sounder (VAS). The AASIR design and interface constraints with the STORMSAT spacecraft is discussed.

  3. Detecting Climate Signatures with High Spectral Resolution Infrared Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Deslover, D. H.; Tobin, D.; Knuteson, R. O.; Revercomb, H. E.

    2013-12-01

    Upwelling atmospheric infrared radiances can be accurately monitored from high spectral resolution satellite observations. The high spectral resolution nature of these measurements affords the ability to track various climate relevant parameters such as window channels sensitive to surface temperature and clouds, channels with higher sensitivity to trace gases including CO2, CH4, SO2, HNO3, as well as channels sensitive only to upper tropospheric or lower stratospheric temperature. NASA's Atmospheric Infrared Sounder (AIRS) provides a data record that extends from its 2002 launch to the present. The Infrared Atmospheric Sounding Interferometer (IASI) onboard Metop- (A launched in 2006, B in 2012), as well as the Joint Polar Satellite System (JPSS) Cross-track Infrared Sounder (CrIS) launched in 2011, complement this data record. Future infrared sounders with similar capabilities will augment these measurements into the distant future. We have created a global data set from the aforementioned satellite observations. Our analysis yields a channel dependent approach that can be further constrained in terms of diurnal, seasonal and geographic limits, with measurement accuracies of better than a few tenths of degree Kelvin. In this study, we have applied this concept to obtain a better understanding of long-term stratospheric temperature trends. We will present a survey of temperature trends for spectral channels that were chosen to be sensitive to stratospheric emission. Results will be shown for tropical, mid-latitude and polar stratospheric observations.

  4. Assimilation of the Microwave Limb Sounder Radiances

    NASA Technical Reports Server (NTRS)

    Wargan, K.; Read, W.; Livesey, N.; Wagner, P.; Nguyen. H.; Pawson, S.

    2012-01-01

    It has been shown that the assimilation of limb-sounder data can significantly improve the representation of ozone in NASA's GEOS Data Assimilation Systems (GEOS-DAS), particularly in the stratosphere. The studies conducted so far utilized retrieved data from the MIPAS, POAM, ILAS and EOS Microwave Limb Sounder (EOS MLS) instruments. Direct assimilation of the radiance data can be seen as the natural next step to those studies. The motivation behind working with radiances is twofold. First, retrieval algorithms use a priori data which are either climatological or are obtained from previous analyses. This introduces additional uncertainty and, in some cases, may lead to "self-contamination"- when the a priori is taken from the same assimilation system in which subsequently ingests the retrieved observations. Second, radiances can be available in near real time thus providing an opportunity for operational assimilation, which could help improve the use of infrared radiance instruments from operational satellite instruments. In this presentation we summarize our ongoing work on an implementation of the assimilation of EOS MLS radiances into the GEOS-5 DAS. This work focuses on assimilation of band 7 brightness temperatures which are sensitive to ozone. Our implementation uses the MLS Callable Forward Model developed by the MLS team at NASA JPL as the observation operator. We will describe our approach and recent results which are not yet final. In particular, we will demonstrate that this approach has a potential to improve the vertical structure of ozone in the lower tropical stratosphere as compared with the retrieved MLS product. We will discuss the computational efficiency of this implementation.

  5. Characteristics of monsoon inversions over the Arabian Sea observed by satellite sounder and reanalysis data sets

    NASA Astrophysics Data System (ADS)

    Dwivedi, Sanjeev; Narayanan, M. S.; Venkat Ratnam, M.; Narayana Rao, D.

    2016-04-01

    Monsoon inversion (MI) over the Arabian Sea (AS) is one of the important characteristics associated with the monsoon activity over Indian region during summer monsoon season. In the present study, we have used 5 years (2009-2013) of temperature and water vapour measurement data obtained from satellite sounder instrument, an Infrared Atmospheric Sounding Interferometer (IASI) onboard MetOp satellite, in addition to ERA-Interim data, to study their characteristics. The lower atmospheric data over the AS have been examined first to identify the areas where MIs are predominant and occur with higher strength. Based on this information, a detailed study has been made to investigate their characteristics separately in the eastern AS (EAS) and western AS (WAS) to examine their contrasting features. The initiation and dissipation times of MIs, their percentage occurrence, strength, etc., has been examined using the huge database. The relation with monsoon activity (rainfall) over Indian region during normal and poor monsoon years is also studied. WAS ΔT values are ˜ 2 K less than those over the EAS, ΔT being the temperature difference between 950 and 850 hPa. A much larger contrast between the WAS and EAS in ΔT is noticed in ERA-Interim data set vis-à-vis those observed by satellites. The possibility of detecting MI from another parameter, refractivity N, obtained directly from another satellite constellation of GPS Radio Occultation (RO) (COSMIC), has also been examined. MI detected from IASI and Atmospheric Infrared Sounder (AIRS) onboard the NOAA satellite have been compared to see how far the two data sets can be combined to study the MI characteristics. We suggest MI could also be included as one of the semipermanent features of southwest monsoon along with the presently accepted six parameters.

  6. Spatiotemporal Evaluation of Nocturnal Cold Air Drainage Over a Simple Slope Using Thermal Infrared Imagery

    NASA Astrophysics Data System (ADS)

    Ikani, V.; Chokmani, K.; Fathollahi, L.; Granberg, H.; Fournier, R.

    2016-06-01

    Measurements of climatic processes such as cold air drainage flows are problematic over mountainous areas. Observation of cold air drainage is not available in the existing observation network and it requires a special methodology. The main objective of this study was to characterize the cold air drainage over regions with a slope. A high resolution infrared camera, a meteorological station and Digital Elevation Model (DEM) were used. The specific objective was to derive nocturnal cold air drainage velocity over the slope. To address these objectives, a number of infrared measurement campaigns were conducted during calm and clear sky conditions over an agricultural zone (blackcurrant farm) in Canada. Using thermal infrared images, the nocturnal surface temperature gradient were computed in hourly basis. The largest gradient magnitudes were found between 17h -20h. The cooling rates at basin area were two times higher in comparison to the magnitudes observed within slope area. The image analysis illustrated this considerable temperature gradient of the basin may be partly due to transport of cold air drainage into the basin from the slope. The results show that thermal imagery can be used to characterize and understand the microclimate related to the occurrence of radiation frost in the agricultural field. This study provided the opportunity to track the cold air drainage flow and pooling of cold air in low lying areas. The infrared analysis demonstrated that nocturnal drainage flow displayed continuous variation in terms of space and time in response to microscale slope heterogeneities. In addition, the analysis highlighted the periodic aspect for cold air drainage flow.

  7. Improving the Air Force Infrared Stellar Calibration Network with High Spectral Resolution Data from the Infrared Space Observatory

    NASA Astrophysics Data System (ADS)

    Kraemer, K. E.; Engelke, C. W.; Price, S. D.

    2004-12-01

    We present preliminary results of a project to improve the spectral resolution of the Air Force Infrared Stellar Calibration Network by incorporating data from the Infrared Space Observatory (ISO). This network and its deriviatives were created by Cohen and colleagues to support infrared calibration for government and civilian ground- and space-based observatories, such as the Infrared Telescope Facility, Gemini, and the Maui Optical Site. The reduced 2.4 to 45 μ m spectra from the ISO Short Wavelength Spectrometer (SWS) are up to 100 times higher spectral resolution than the current network data. Appropriately substituting these spectra for the standard stars will improve the accuracy of the calibration network, particularly in spectral regions where the atmosphere limits ground-based data, and permit more accurate calibration of very narrow spectral bandpasses. The initial effort has photometrically calibrated the SWS spectra for the 9 stellar or secondary standards with composites. The model atmosphere spectrum for α Cen has been replaced by SWS data; the model spectra for α CMa and α Lyr have been retained in order to preserve the common calibration pedigree with the original Cohen et al. network (although see Price et al. 2004, AJ, 128, 889). Where available, high quality photometry from the Midcourse Space Experiment (MSX) are used, supplemented by photometry from the Diffuse Infrared Background Experment (DIRBE) and the photometry used by Cohen et al. used to create the original composite. The next steps are to 1) replace the 10-15 tertiary standard stars with template spectra with measured spectra for the cases in which the SWS observations have sufficiently high signal-to-noise ratios (this will double the number of secondary standards); 2) develop a set of high spectral resolution infrared templates based on the SWS observations for each MK spectral class of the secondary standards with which to upgrade the entire network; 3) create new templates for

  8. Modelling an infrared Man Portable Air Defence System

    NASA Astrophysics Data System (ADS)

    Birchenall, Richard P.; Richardson, Mark A.; Brian, Butters; Roy, Walmsley

    2010-09-01

    The global proliferation of shoulder launched IR Man Portable Air Defence Systems (ManPADS) has resulted in the existence of a serious threat to both civilian and military aircraft from terrorist attack. Some of the older generations of ManPADS can be defeated with modern countermeasures but even the most sophisticated protection still has vulnerabilities to the latest family of ManPADS. This paper describes the work undertaken by the authors to model a second generation ManPAD, based on the Russian SA-14, and assess the vulnerabilities of aircraft both with and without flare countermeasures from these systems. The conclusions are the results of over 11,000 simulated firings against targets of varying aspects, velocities and altitudes.

  9. Drying of chilli in a combined infrared and hot air rotary dryer.

    PubMed

    Mihindukulasuriya, Suramya D F; Jayasuriya, Hemantha P W

    2015-08-01

    The investigation of an economical and efficient drying method for chilli is beneficial because it could provide a means of overcoming the drawbacks of traditional drying methods: high operating power and long drying time, which result in a decrease in the quality of the chilli. This study involved the design and development of a combined infrared and hot air laboratory-scale rotary dryer, which consists of three operating modes: hot air, infrared, and combined infrared and hot air. Drying experiments were conducted at five different temperatures (50, 55, 60, 65, and 70 °C). The drying behavior produced with the three operating modes was evaluated. The best mode was determined based on the parameters for evaluating the quality of chilli, the power consumption, and the retention time. The results indicate that the optimal overall drying performance for chilli was achieved at 70, 65, 50 °C drying temperatures in hot air, combined, and IR mode, respectively. A positive correlation was observed between retention time and power consumption with the hot air and the combined modes, while a negative correlation was identified in the IR mode. PMID:26243909

  10. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zhang, X.; Zavodsky, B. T.; Heinrichs, T.; Broderson, D.

    2014-01-01

    A case study and monthly statistical analysis using sounder data assimilation to improve the Alaska regional weather forecast model are presented. Weather forecast in Alaska faces challenges as well as opportunities. Alaska has a large land with multiple types of topography and coastal area. Weather forecast models must be finely tuned in order to accurately predict weather in Alaska. Being in the high-latitudes provides Alaska greater coverage of polar orbiting satellites for integration into forecasting models than the lower 48. Forecasting marine low stratus clouds is critical to the Alaska aviation and oil industry and is the current focus of the case study. NASA AIRS/CrIS sounder profiles data are used to do data assimilation for the Alaska regional weather forecast model to improve Arctic marine stratus clouds forecast. Choosing physical options for the WRF model is discussed. Preprocess of AIRS/CrIS sounder data for data assimilation is described. Local observation data, satellite data, and global data assimilation data are used to verify and/or evaluate the forecast results by the MET tools Model Evaluation Tools (MET).

  11. Next Generation Grating Spectrometer Sounders for LEO and GEO

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2011-01-01

    AIRS and MODIS are widely used for weather, climate, composition, carbon cycle, cross-calibration, and applications. The community asking for new capability in the 2020 timeframe, capabilities desired: (1) Hyperspectral UV to LWIR, High Spatial ?1km IFOV (2) Maximize Synergies of Solar Reflected and IR. Synergies with OCO-2. We expect more users and applications of next gen LEO IR Sounder than GEO. These include: weather, climate, GHG monitoring, aviation, disaster response. There is a new direction for imagers and sounders: (1) Separate Vis/NIR/SWIR from MWIR/LWIR instruments reduces technology risk and complexity. (2) Expect Costs to be lower than CrIS & VIIRS Some additional ideas to reduce costs include: (1) minimum set of requirements (2) mini-grating spectrometers. supports constellation for higher revisit (3) new technology to reduce instrument size (large format fpa's) (4) hosted payloads

  12. GEO/SAMS - The Geostationary Synthetic Aperture Microwave Sounder

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn H.

    2008-01-01

    The National Oceanic and Atmospheric Administration (NOAA) has for many years operated two weather satellite systems, the Polar-orbiting Operational Environmental Satellite system (POES), using low-earth orbiting (LEO) satellites, and the Geostationary Operational Environmental Satellite system (GOES), using geostationary earth orbiting (GEO) satellites. (Similar systems are also operated by other nations.) The POES satellites have been equipped with both infrared (IR) and microwave (MW) atmospheric sounders, which makes it possible to determine the vertical distribution of temperature and humidity in the troposphere even under cloudy conditions. Such satellite observations have had a significant impact on weather forecasting accuracy, especially in regions where in situ observations are sparse. In contrast, the GOES satellites have only been equipped with IR sounders, since it has not been feasible to build a large enough antenna to achieve sufficient spatial resolution for a MW sounder in GEO. As a result, GOES soundings can only be obtained in cloud free areas and in the less important upper atmosphere, above the cloud tops. This has hindered the effective use of GOES data in numerical weather prediction. Full sounding capabilities with the GOES system is highly desirable because of the advantageous spatial and temporal coverage that is possible from GEO. While POES satellites provide coverage in relatively narrow swaths, and with a revisit time of 12-24 hours or more, GOES satellites can provide continuous hemispheric coverage, making it possible to monitor highly dynamic phenomena such as hurricanes.

  13. Average Tropical Relative Humidity from AIRS, Dec-Feb 2002-2005

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The average tropospheric relative humidity from AIRS for the four December-February periods during 2002 through 2005.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  14. Infrared Spectral Radiance Intercomparisons With Satellite and Aircraft Sensors

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Zhou, Daniel K.; Liu, Xu; Smith, William L.

    2014-01-01

    Measurement system validation is critical for advanced satellite sounders to reach their full potential of improving observations of the Earth's atmosphere, clouds, and surface for enabling enhancements in weather prediction, climate monitoring capability, and environmental change detection. Experimental field campaigns, focusing on satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft, are an essential part of the validation task. Airborne FTS systems can enable an independent, SI-traceable measurement system validation by directly measuring the same level-1 parameters spatially and temporally coincident with the satellite sensor of interest. Continuation of aircraft under-flights for multiple satellites during multiple field campaigns enables long-term monitoring of system performance and inter-satellite cross-validation. The NASA / NPOESS Airborne Sounder Testbed - Interferometer (NAST-I) has been a significant contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This presentation gives an overview of benefits achieved using airborne sensors such as NAST-I utilizing examples from recent field campaigns. The methodology implemented is not only beneficial to new sensors such as the Cross-track Infrared Sounder (CrIS) flying aboard the Suomi NPP and future JPSS satellites but also of significant benefit to sensors of longer flight heritage such as the Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) on the AQUA and METOP-A platforms, respectively, to ensure data quality continuity important for climate and other applications. Infrared spectral radiance inter-comparisons are discussed with a particular focus on usage of NAST-I data for enabling inter-platform cross-validation.

  15. Suspended Si/air high contrast subwavelength gratings for long-wavelength infrared reflectors

    NASA Astrophysics Data System (ADS)

    Foley, Justin M.; Phillips, Jamie D.

    2013-03-01

    We report broadband reflectance in the long-wavelength infrared (LWIR, 8-12 μm) utilizing suspended-Si, high-index-contrast subwavelength gratings (HCGs). Iterative design optimization using finite element analysis software has been performed accounting for silicon's wavelength-dependent index of refraction and extinction coefficient. Grating arrays were fabricated using commercial silicon-on-insulator (SOI) substrates, photolithography and reactive ion etching; subsequent selective wet etching of SiO2 was used to provide suspended Si/air gratings. Fourier transform infrared (FTIR) spectroscopy demonstrates broadband, polarization-dependent reflectance between 8.5 and 12 μm, which agrees with the simulated response.

  16. CfAIR2: Near-infrared Light Curves of 94 Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Friedman, Andrew S.; Wood-Vasey, W. M.; Marion, G. H.; Challis, Peter; Mandel, Kaisey S.; Bloom, Joshua S.; Modjaz, Maryam; Narayan, Gautham; Hicken, Malcolm; Foley, Ryan J.; Klein, Christopher R.; Starr, Dan L.; Morgan, Adam; Rest, Armin; Blake, Cullen H.; Miller, Adam A.; Falco, Emilio E.; Wyatt, William F.; Mink, Jessica; Skrutskie, Michael F.; Kirshner, Robert P.

    2015-09-01

    CfAIR2 is a large, homogeneously reduced set of near-infrared (NIR) light curves (LCs) for Type Ia supernovae (SNe Ia) obtained with the 1.3 m Peters Automated InfraRed Imaging TELescope. This data set includes 4637 measurements of 94 SNe Ia and 4 additional SNe Iax observed from 2005 to 2011 at the Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona. CfAIR2 includes {{JHK}}s photometric measurements for 88 normal and 6 spectroscopically peculiar SN Ia in the nearby universe, with a median redshift of z ˜ 0.021 for the normal SN Ia. CfAIR2 data span the range from -13 days to +127 days from B-band maximum. More than half of the LCs begin before the time of maximum, and the coverage typically contains ˜13-18 epochs of observation, depending on the filter. We present extensive tests that verify the fidelity of the CfAIR2 data pipeline, including comparison to the excellent data of the Carnegie Supernova Project. CfAIR2 contributes to a firm local anchor for SN cosmology studies in the NIR. Because SN Ia are more nearly standard candles in the NIR and are less vulnerable to the vexing problems of extinction by dust, CfAIR2 will help the SN cosmology community develop more precise and accurate extragalactic distance probes to improve our knowledge of cosmological parameters, including dark energy and its potential time variation.

  17. GEOSTAR - a microwave sounder for GOES-R

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn; Wilson, William; Tanner, Alan

    2005-01-01

    The National Oceanic and Atmospheric Administration (NOAA) has for many years operated two weather satellite systems, the Polar-orbiting Operational Environmental Satellite system (POES), using low-earth orbiting (LEO) satellites, and the Geostationary Operational Environmental Satellite system (GOES), using geostationary earth orbiting (GEO) satellites. Similar systems are also operated by other nations. The POES satellites have been equipped with both infrared (IR) and microwave (MW) atmospheric sounders, which together make it possible to determine the vertical distribution of temperature and humidity in the troposphere even under cloudy conditions.

  18. Current Sounding Capability From Satellite Meteorological Observation With Ultraspectral Infrared Instruments

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.

    2008-01-01

    Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. The intent of the measurement of tropospheric thermodynamic state and trace abundances is the initialization of climate models and the monitoring of air quality. The NPOESS Airborne Sounder Testbed-Interferometer (NAST-I), designed to support the development of future satellite temperature and moisture sounders, aboard high altitude aircraft has been collecting data throughout many field campaigns. An advanced retrieval algorithm developed with NAST-I is now applied to satellite data collected with the Atmospheric InfraRed Sounder (AIRS) on the Aqua satellite launched on 4 May 2002 and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite launched on October 19, 2006. These instruments possess an ultra-spectral resolution, for example, both IASI and NAST-I have 0.25 cm-1 and a spectral coverage from 645 to 2760 cm-1. The retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. The physical inversion scheme has been developed, dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders, to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A fast radiative transfer model, which applies to the clouded atmosphere, is used for atmospheric profile and cloud parameter retrieval. A one-dimensional (1-d) variational multi-variable inversion solution is used to improve an iterative background state defined by an eigenvector-regression-retrieval. The solution is iterated in order to account for non-linearity in the 1-d variational solution. It is shown that relatively accurate temperature and moisture retrievals can be achieved below optically thin clouds. For optically thick clouds, accurate temperature and moisture profiles down to

  19. AIRS Retrieval Validation During the EAQUATE

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Smith, William L.; Cuomo, Vincenzo; Taylor, Jonathan P.; Barnet, Christopher D.; DiGirolamo, Paolo; Pappalardo, Gelsomina; Larar, Allen M.; Liu, Xu; Newman, Stuart M.

    2006-01-01

    Atmospheric and surface thermodynamic parameters retrieved with advanced hyperspectral remote sensors of Earth observing satellites are critical for weather prediction and scientific research. The retrieval algorithms and retrieved parameters from satellite sounders must be validated to demonstrate the capability and accuracy of both observation and data processing systems. The European AQUA Thermodynamic Experiment (EAQUATE) was conducted mainly for validation of the Atmospheric InfraRed Sounder (AIRS) on the AQUA satellite, but also for assessment of validation systems of both ground-based and aircraft-based instruments which will be used for other satellite systems such as the Infrared Atmospheric Sounding Interferometer (IASI) on the European MetOp satellite, the Cross-track Infrared Sounder (CrIS) from the NPOESS Preparatory Project and the following NPOESS series of satellites. Detailed inter-comparisons were conducted and presented using different retrieval methodologies: measurements from airborne ultraspectral Fourier transform spectrometers, aircraft in-situ instruments, dedicated dropsondes and radiosondes, and ground based Raman Lidar, as well as from the European Center for Medium range Weather Forecasting (ECMWF) modeled thermal structures. The results of this study not only illustrate the quality of the measurements and retrieval products but also demonstrate the capability of these validation systems which are put in place to validate current and future hyperspectral sounding instruments and their scientific products.

  20. AIRS radiometric calibration validation for climate research

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Pagano, Thomas S.; Elliott, Denis; Gaiser, Steve; Gregorich, Dave; Broberg, Steve

    2005-01-01

    Climate research using data from satellite based radiometers makes extreme demands on the traceability and stability of the radiometric calibration. The selection of a cooled grating array spectrometer for the Atmospheric Infrared Sounder, AIRS, is key, but does not ensured that AIRS data will be of climate quality. Additional design features, plus additional pre-launch testing, and extensive on-orbit calibration subsystem monitoring beyond what would suffice for application of the data to weather forecasting were required to ensure the radiometric data quality required for climate research. Validation that climate data quality are being generated makes use of the sea surface skin temperatures (SST and (obs-calc).

  1. The validation of AIRS retrievals

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Olsen, Edward T.; Chen, Luke L.; Hagan, Denise E.; Fishbein, Evan; McMillin, Larry; Zhou, Jiang; McMillan, Wallace W.

    2003-01-01

    The initial validation of Atmospheric Infrared Sounder (SIRS) experiment retrievals were completed in August 2003 as part of public release of version 3.0 data. The associated analyses are reported at http://daac.gsfc.nasa.gov/atmodyn/airs/, where data may be accessed. Here we describe some of those analyses, with an emphasis on cloud cleared radiances, atmospheric temperature profiles, sea surface temperature, total water vapor and atmospheric water vapor profiles. The results are applicable over ocean in the latitude band +/-40 degrees.

  2. The temperature fields measurement of air in the car cabin by infrared camera

    NASA Astrophysics Data System (ADS)

    Pešek, M.

    2013-04-01

    The article deals with the temperature fields measurement of air using the Jenoptic Variocam infrared camera inside the car Škoda Octavia Combi II. The temperature fields with the use of auxiliary material with a high emissivity value were visualized. The measurements through the viewing window with a high transmissivity value were performed. The viewing windows on the side car door were placed. In the rear car area, the temperature fields of air on the spacious sheet of auxiliary material were visualized which is a suitable method for 2D airstreams. In the front car area, the temperature fields in the air were measured with the use of the measuring net which is suitable for 3D airstreams measuring.

  3. NASA GES DISC DAAC Data Holdings for AIRS/Aqua

    NASA Astrophysics Data System (ADS)

    Cho, S.; Phelps, C. S.; Sharma, A. K.; Qin, J.

    2002-12-01

    The Atmospheric Infrared Sounder (AIRS) is a high-resolution infrared sounder on the Earth Observing System polar-orbiting platform, EOS Aqua, which was successfully launched on May 4, 2002. AIRS is closely coupled with two microwave instruments, the Advanced Microwave Sounding Unit (AMSU-A) and the Humidity Sounder for Brazil (HSB). The data products from AIRS/AMSU-A/HSB are archived and distributed at the Distributed Active Archive Center (DAAC) located at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). AIRS has 2,378 channels measuring in the infrared range 3.74-15.4 μm and four channels measuring in the visible/near-infrared range 0.4-1.1 μm. AMSU-A is a temperature sounder that primarily provides atmospheric information in the presence of clouds, which is used to correct the AIRS infrared measurements for the effects of the clouds. Likewise, HSB provides information on snow/ice cover, precipitation, and the coarse distribution of moisture in the troposphere. Combined with simultaneous measurements from AIRS, the calibrated brightness temperature from AMSU-A and HSB is used to initialize the atmospheric moisture profile required for the retrieval of the final AIRS geophysical products. The data product suite includes level 1B combined, geolocated and calibrated radiances and will include level 2 final retrievals of surface skin temperature, surface albedo, integrated precipitable water, radiative fluxes, various cloud properties and trace gases (ozone, methane, carbon dioxide, and carbon monoxide). Furthermore, AIRS/AMSU-A/HSB will obtain atmospheric temperature profiles with an accuracy of 1K for every 1 km layer in the troposphere (1K for every 4 km layer in stratosphere) and humidity profiles with an accuracy 20% in 2 km layers from the surface up through the troposphere. Global coverage is obtained twice daily (day and night) on a 1:30 p.m. sun-synchronous orbit from a 705-km altitude. For processing convenience, the data

  4. Multiorder etalon sounder (MOES) development and test for balloon experiment

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.; Wnag, Jinxue; Wu, Jian

    1993-01-01

    The Fabry-Perot interferometer (FPI), with its high throughput and high spectral resolution has been used in the remote-sensing measurements of the earth's atmospheric composition, winds, and temperatures. The most recent satellite instruments include the Fabry-Perot interferometer flown on the Dynamics Explorer-2 (DE-2), the High Resolution Doppler Imager (HRDI), and the Cryogenic Limb Array Etalon Spectrometer (CLAES) flown on the Upper Atmosphere Research Satellite (UARS). These instruments measure the Doppler line profiles of the emission and absorption of certain atmospheric species (such as atomic oxygen) in the visible and infrared spectral region. The successful space flight of DE-FPI, HRDI, and CLAES on UARS demonstrated the extremely high spectral resolution and ruggedness of the etalon system for the remote sensing of earth and planetary atmospheres. Recently, an innovative FPI focal plane detection technique called the Circle-to-Line Interferometer Optical (CLIO) system was invented at the Space Physics Research Laboratory. The CLIO simplifies the FPI focal plane detection process by converting the circular rings or fringes into a linear pattern similar to that produced by a conventional spectrometer, while retaining the throughput advantage of the etalon interferometer. The combination of FPI and CLIO allows the development of more sensitive Fabry-Perot interferometers in the infrared for the remote sensing of the lower atmospheres of Earth and possibly other planets. The Multiorder Etalon Sounder (MOES), a combination of the rugged etalon and the CLIO, compares very favorably to other space-borne optical instruments in terms of performance versus complexity. The new instrument is expected to be rugged, compact, and very suitable for an operational temperature and moisture sounder. With this technique, the contamination of radiance measurements by emissions of other gases is also minimized. At the Space Physics Research Laboratory (SPRL), the MOES

  5. Cris-atms Retrievals Using an AIRS Science Team Version 6-like Retrieval Algorithm

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Kouvaris, Louis C.; Iredell, Lena

    2014-01-01

    CrIS is the infrared high spectral resolution atmospheric sounder launched on Suomi-NPP in 2011. CrISATMS comprise the IRMW Sounding Suite on Suomi-NPP. CrIS is functionally equivalent to AIRS, the high spectral resolution IR sounder launched on EOS Aqua in 2002 and ATMS is functionally equivalent to AMSU on EOS Aqua. CrIS is an interferometer and AIRS is a grating spectrometer. Spectral coverage, spectral resolution, and channel noise of CrIS is similar to AIRS. CrIS spectral sampling is roughly twice as coarse as AIRSAIRS has 2378 channels between 650 cm-1 and 2665 cm-1. CrIS has 1305 channels between 650 cm-1 and 2550 cm-1. Spatial resolution of CrIS is comparable to AIRS.

  6. AIRS First Light Data: Eastern Mediterranean, June 14, 2002

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2Figure 3

    Four images of the Mediterranean obtained concurrently on June 14, 2002 from the three instruments that make up the Atmospheric Infrared Sounder experiment system aboard NASA's Aqua spacecraft. The system features thousands of individual channels that observe Earth in the visible, infrared and microwave spectral regions. Each channel has a unique sensitivity to temperature, moisture, surface conditions and clouds.

    This visible light image from the AIRS instrument shows a band of white clouds extending from the Adriatic Sea over Greece to the Black Sea.

    The AIRS image (figure 1) at 900 cm-1 (11 micrometers) measures actual surface or cloud top temperatures. In it, land and ocean boundaries are well defined, with land appearing as warmer (darker red) than the ocean. The band of cold high cumulus clouds appears blue, with the darkest blue most likely a large thunderstorm.

    The 150 gigahertz channel from the Humidity Sounder for Brazil instrument (figure 2) is sensitive to moisture, ice particles and precipitation. The dry land temperature is comparable to the 11 micrometer temperatures, but over ocean this channel measures the temperature of moisture in the mid troposphere. The cold, blue areas off Sicily and in the Aegean Sea represent unusually dry areas over the ocean. There, clouds appear as green filaments--likely areas of precipitation.

    The 31.4 gigahertz channel from the Advanced Microwave Sounding Unit instrument (figure 3) is not affected by clouds.

    NASA's Atmospheric Infrared Sounder (AIRS) onboard NASA's Aqua spacecraft, began sending high quality data on June 12, 2002. This 'first light' data is exceeding the expectations of scientists, confirming that the AIRS experiment is well on its way to meeting its goals of improving weather forecasting, establishing the connection between severe weather and

  7. Air Force electronic warfare evaluation simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Shepherd, Seth D.

    2003-09-01

    The Air Force Electronic Warfare Evaluation Simulator (AFEWES) Infrared Countermeasures (IRCM) test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, point-source flares and lamp- and LASER-based jammer systems. The simulations of IR missiles in flight include missile seeker hardware mounted on a six degree-of-freedom flight simulation table. This paper will focus on recent developments and upgrades to the AFEWES IR capability.

  8. Optical Alignment and Diffraction Analysis for AIRES: An Airborne Infrared Echelle Spectrometer

    NASA Technical Reports Server (NTRS)

    Haas, Michael R.; Fonda, Mark (Technical Monitor)

    2002-01-01

    The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed.

  9. AIRS Data Mining Service at the Goddard Earth Sciences (GES) DISC DAAC

    NASA Astrophysics Data System (ADS)

    Vicente, G. A.; Qin, J.; Pham, L.; Lynnes, C.; Eng, E.; Li, J.

    2004-05-01

    The Atmospheric Infrared Sounder (AIRS) is a high-resolution infrared (IR) sounder with 2378 spectral channels flying on the EOS Aqua platform with two operational microwave sounders, the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB). Measurements from the three instruments are analyzed jointly to filter out the effects of clouds from the IR data in order to derive clear-column air-temperature profiles and surface temperatures with high vertical resolution and accuracy. Together, these three instruments constitute an advanced operational sounding data system that have contributed to improve global modeling efforts and numerical weather prediction; enhance studies of the global energy and water cycles, the effects of greenhouse gases, and atmosphere-surface interactions; and facilitate monitoring of climate variations and trends. The NASA Goddard Earth Sciences Data and Information Services Center/Distributed Active Archive Center (GES DISC DAAC) provides long-term archive and distribution services for AIRS/AMSU/HSB data products as well science support to assist users in understanding, accessing and using the AIRS data products. However, the high data volume generated by the AIRS/AMSU/HSB instruments and the complexity of its data format (Hierarchical Data Format, HDF) are barriers to AIRS data use. Although many researchers are interested in only a fraction of the data they receive or request, they are forced to run their algorithms on a much larger data set to extract the information of interest. In order to address this problem, the GES DAAC is expanding its data mining system to accept AIRS user's algorithms by providing online tools for spectral channels and value added product sub-settings, as well as spatial, temporal and user defined profile sub-settings. This presentation will show details of the AIRS components of the GES DAAC data mining system including technical description, input data and returning products

  10. Topside sounders as mobile ionospheric heaters

    NASA Technical Reports Server (NTRS)

    Benson, R. F.

    2006-01-01

    There is evidence that satellite-borne RF sounders can act as mobile ionospheric heaters in addition to performing topside sounding. The main objective of topside sounding is to use sounder-generated electromagnetic (em) waves to obtain ionospheric topside vertical electron-density (N(sub e) profiles. These profiles are obtained from mathematical inversions of the frequency vs. delay-time ionospheric reflection traces. In addition to these em reflection traces, a number of narrowband intense signals are observed starting at zero delay times after the transmitted pulses. Some of these signals, termed plasma resonances, appear at characteristic frequencies of the ambient medium such as at the electron cyclotron frequency f(sub ce), the harmonics nf(sub ce), the electron plasma frequency f(sub pe) and the upper-hybrid frequency f(sub uh), where (f(sub uh))(exp 2) = (f(sub ce))(exp 2) + (f(sub pe))(exp 2) . These signals have been attributed to the oblique echoes of sounder-generated electrostatic (es) waves. These resonances provide accurate in situ f(sub pe) and f(sub ce) values which, in turn, lead to accurate N(sub e) and [B] values where B is the ambient magnetic field. Resonances are also observed between the nf(sub ce) harmonics both above and below f(sub uh). The former, known as the Qn plasma resonances, are mainly attributed to the matching of the wave group velocity of sounder-generated (Bernstein-mode) es waves to the satellite velocity. The frequency spectrum of these waves in the magnetosphere can be used to detect non-Maxwellian electron velocity-distributions. In addition, these resonances also exhibit components that appear to be the result of plasma emissions stimulated by the sounder pulses. The plasma resonances observed between the nf(sub ce) harmonics and below f(sub uh), known as the Dn plasma resonances, are entirely attributed to such sounder-stimulated plasma emissions. There are other sounder-stimulated plasma phenomena that also fall into

  11. Infrared pulse characterization using four-wave mixing inside a few cycle pulse filament in air

    SciTech Connect

    Marceau, Claude Thomas, Steven; Kassimi, Yacine; Gingras, Guillaume; Witzel, Bernd

    2014-02-03

    We demonstrate a four-wave mixing (FWM) technique to measure near- and mid-infrared (IR) laser pulse shapes in time domain. Few cycle 800 nm laser pulses were synchronized with the IR pulse and focused colinearly to generate a plasma filament in air. Second harmonic radiation around 400 nm was generated through FWM, with a yield proportional to the IR pulse intensity. Excellent signal to noise ratio was observed from 2.1 μm to 18 μm. With proper phase stabilization of the IR beam, this technique is a promising step toward direct electric field sensing of near-IR pulses in air.

  12. Typhoon Saomai as seen by AIRS

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    This is an infrared image of Typhoon Saomai from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on August 10, 2006. This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the typhoon. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red).

    Figure 1 is created from microwave radiation emitted by Earth's atmosphere and received by the instrument. It shows where the heaviest rainfall is taking place (in blue) in the storm. Blue areas outside of the storm where there are either some clouds or no clouds, indicate where the sea surface shines through.

    In figure 3, Typhoon Saomai is captured by the visible light/near-infrared sensor on the AIRS instrument.

    At the time the data were taken from which these images were made, the Typhoon Saomai was nearly on-shore in China with winds of 130mph, and the storm has a well developed eye.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract

  13. Added value of a geostationary thermal infrared and visible instrument to monitor ozone for air quality

    NASA Astrophysics Data System (ADS)

    Hache, Emeric; Attié, Jean-Luc; Tourneur, Cyrille; Ricaud, Philippe; Coret, Laurent; Lahoz, William; El Amraoui, Laaziz; Josse, Béatrice; Hamer, Paul; Warner, Juying; Liu, Xiong; Chance, Kelly; Höpfner, Michael; Spurr, Robert; Natraj, Vijay; Kulawik, Susan; Eldering, Annmarie; Orphal, Johannes

    2014-05-01

    Air quality concerns the atmospheric composition of the lowermost troposphere between the ground and 500 m; it depends on chemical and transport processes and emissions. Air quality has a strong impact on human health, and protecting society from its adverse effects has a high cost (Lahoz et al., 2012). It is thus important to monitor species that are key for air quality - these include ozone, carbon monoxide, NOx and aerosols. In this study we focus on ozone, and compare the capability of two instrument configurations onboard a geostationary (GEO) satellite to sense ozone in the lowermost troposphere (surface and 0-1 km column): 1) in the thermal infrared (GEO TIR), and 2) in the thermal infrared and the visible (GEO TIR+VIS). We consider one week during the Northern Hemisphere summer simulated by the chemical transport model MOCAGE, and use the two GEO instrument configurations to measure ozone. The GEO TIR instrument is described in Claeyman et al. (2011a, b). The GEO TIR+VIS instrument is the GEO TIR instrument with an additional visible Chappuis band to improve the sensitivity of the instrument in the lowermost troposphere. We compare these configurations against each other, and against an ozone reference state and a priori ozone information, to evaluate the benefit of the TIR+VIS in comparison to the TIR in the lowermost troposphere. The results from this work will inform an Observing System Simulation Experiment (OSSE) performed to quantify the added value of the GEO TIR+VIS configuration for forecasting air quality conditions.

  14. Applications Using AIRS Data

    NASA Astrophysics Data System (ADS)

    Ray, S. E.; Pagano, T. S.; Fetzer, E. J.; Lambrigtsen, B.; Olsen, E. T.; Teixeira, J.; Licata, S. J.; Hall, J. R.; Thompson, C. K.

    2015-12-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. With a 12-year data record and daily, global observations in near real-time, AIRS data can play a role in applications that fall under many of the NASA Applied Sciences focus areas. For vector-borne disease, research is underway using AIRS near surface retrievals to assess outbreak risk, mosquito incubation periods and epidemic potential for dengue fever, malaria, and West Nile virus. For drought applications, AIRS temperature and humidity data are being used in the development of new drought indicators and improvement in the understanding of drought development. For volcanic hazards, new algorithms using AIRS data are in development to improve the reporting of sulfur dioxide concentration, the burden and height of volcanic ash and dust, all of which pose a safety threat to aircraft. In addition, anomaly maps of many of AIRS standard products are being produced to help highlight "hot spots" and illustrate trends. To distribute it's applications imagery, AIRS is leveraging existing NASA data frameworks and organizations to facilitate archiving, distribution and participation in the BEDI. This poster will communicate the status of the applications effort for the AIRS Project and provide examples of new maps designed to best communicate the AIRS data.

  15. Cloudy Sounding and Cloud-Top Height Retrieval From AIRS Alone Single Field-of-View Radiance Measurements

    NASA Technical Reports Server (NTRS)

    Weisz, Elisabeth; Li, Jun; Li, Jinlong; Zhou, Daniel K.; Huang, Hung-Lung; Goldberg, Mitchell D.; Yang, Ping

    2007-01-01

    High-spectral resolution measurements from the Atmospheric Infrared Sounder (AIRS) onboard the EOS (Earth Observing System) Aqua satellite provide unique information about atmospheric state, surface and cloud properties. This paper presents an AIRS alone single field-of-view (SFOV) retrieval algorithm to simultaneously retrieve temperature, humidity and ozone profiles under all weather conditions, as well as cloud top pressure (CTP) and cloud optical thickness (COT) under cloudy skies. For optically thick cloud conditions the above-cloud soundings are derived, whereas for clear skies and optically thin cloud conditions the profiles are retrieved from 0.005 hPa down to the earth's surface. Initial validation has been conducted by using the operational MODIS (Moderate Resolution Imaging Spectroradiometer) product, ECMWF (European Center of Medium range Weather Forecasts) analysis fields and radiosonde observations (RAOBs). These inter-comparisons clearly demonstrate the potential of this algorithm to process data from 38 high-spectral infrared (IR) sounder instruments.

  16. Mechanical Description of the Mars Climate Sounder Instrument

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.

    2008-01-01

    This paper introduces the Mars Climate Sounder (MCS) Instrument of the Mars Reconnaissance Orbiter (MRO) spacecraft. The instrument scans the Martian atmosphere almost continuously to systematically acquire weather and climate observations over time. Its primary components are an optical bench that houses dual telescopes with a total of nine channels for visible and infrared sensing, and a two axis gimbal that provides pointing capabilities. Both rotating joints consist of an integrated actuator with a hybrid planetary/harmonic transmission and a twist cap section that enables the electrical wiring to pass through the rotating joint. Micro stepping is used to reduce spacecraft disturbance torques to acceptable levels while driving the stepper motors. To ensure survivability over its four year life span, suitable mechanical components, lubrication, and an active temperature control system were incorporated. Some life test results and lessons learned are provided to serve as design guidelines for actuator parts and flex cables.

  17. Near-infrared Laser-induced Temperature Elevation in Optically-trapped Aqueous Droplets in Air.

    PubMed

    Ishizaka, Shoji; Ma, Jiang; Fujiwara, Terufumi; Yamauchi, Kunihiro; Kitamura, Noboru

    2016-01-01

    Near-infrared laser-induced temperature elevation in single aqueous ammonium sulfate droplets levitated in air were evaluated by means of laser trapping and Raman spectroscopy. Since the vapor pressure in an aqueous solution droplet should be thermodynamically in equilibrium with that of water in air, the equilibrium size of the droplet varies sensitively through evaporation/condensation of water in accordance with the temperature change of the droplet. In this study, we demonstrated that the changes in the size of an optically levitated aqueous ammonium sulfate droplet were induced by irradiation of a 1064-nm laser beam as a heat source under an optical microscope. Temperature elevation in the droplet was evaluated successfully by means of Raman spectroscopy, and the values determined were shown to be in good agreement with those by the theoretical calculations based on the absorption coefficient of water at 1064-nm and the thermal conductivity of air. To the best of our knowledge, this is the first experimental demonstration showing that the absorption coefficient evaluated from changes in the size of optically-trapped aqueous droplets is consistent with that of pure water. PMID:27063715

  18. AIRS Maps from Space Processing Software

    NASA Technical Reports Server (NTRS)

    Thompson, Charles K.; Licata, Stephen J.

    2012-01-01

    This software package processes Atmospheric Infrared Sounder (AIRS) Level 2 swath standard product geophysical parameters, and generates global, colorized, annotated maps. It automatically generates daily and multi-day averaged colorized and annotated maps of various AIRS Level 2 swath geophysical parameters. It also generates AIRS input data sets for Eyes on Earth, Puffer-sphere, and Magic Planet. This program is tailored to AIRS Level 2 data products. It re-projects data into 1/4-degree grids that can be combined and averaged for any number of days. The software scales and colorizes global grids utilizing AIRS-specific color tables, and annotates images with title and color bar. This software can be tailored for use with other swath data products for the purposes of visualization.

  19. Evaluation of Vertically Resolved Water Winds from AIRS using Hurricane Katrina

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Dobkowski, Edwin C.; Gregorich, David T.

    2005-01-01

    The knowledge of wind velocity as a function of altitude is key to weather forecast improvements. The ability of hyperspectral sounders in principle to measure vertically resolved water winds, which has long been recognized, has been tested with Atmospheric Infrared Sounder (AIRS) data. AIRS retrievals of total column water above 300 mb have been correlated with the radiosonde upper-tropospheric wind velocity and moisture data. The excellent correlation is illustrated with results obtained from hurricane Katrina and from the western United States. AIRS is a hyperspectral infrared sounder in low Earth orbit. It was launched in May 2002. We illustrate the use of AIRS data for the measurement of upper tropospheric water by using the 2387/cm CO2 R-branch channel and the 1551/cm water vapor channel. The 2387/cm channel measures the temperature at 300 mb totally independent of water vapor. The weighting function of the 1551/cm channel peaks at 300 mb only under moist conditions; the peak shifts downward (higher temperature) for less water and upward (lower temperature) for more water. The difference between the brightness temperatures bt2387 and bt1551 cancels the local several degree weather related variability of the temperature and measures the component due to the water vapor at 300 mb.

  20. Advanced Atmospheric Sounder and Imaging Radiometer (AASIR)

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Design information for the Advanced Atmospheric Sounder and Imaging Radiometer is reported, which was developed to determine the configuration of a sensor for IR and visible imaging. The areas of technology reported include: systems design, optics, mechanics, electronics, detectors, radiative cooler, and radiometric calibration.

  1. Variability in AIRS-retrieved cloud amount and thermodynamic phase over west versus east Antarctica influenced by the SAM

    NASA Astrophysics Data System (ADS)

    Lubin, Dan; Kahn, Brian H.; Lazzara, Matthew A.; Rowe, Penny; Walden, Von P.

    2015-02-01

    In a sample of summertime cloud retrievals from the NASA Atmospheric Infrared Sounder (AIRS), a positive Southern Annular Mode (SAM) index polarity is associated with greater cloud frequency and larger effective cloud fraction over West Antarctica compared with a negative SAM index polarity. The opposite result appears over the high East Antarctic Plateau. Comparing AIRS-retrieved cloud fraction with Antarctic Automatic Weather Station 2 m air temperature data, a positive and significant correlation is found over most of West Antarctica, signifying a longwave heating effect of clouds. Over East Antarctica correlations between Sun elevation and 2 m air temperature are strongest, consistent with lower cloud amount.

  2. Two-photon vibrational excitation of air by long-wave infrared laser pulses

    NASA Astrophysics Data System (ADS)

    Palastro, J. P.; Peñano, J.; Johnson, L. A.; Hafizi, B.; Wahlstrand, J. K.; Milchberg, H. M.

    2016-08-01

    Ultrashort long-wave infrared (LWIR) laser pulses can resonantly excite vibrations in N2 and O2 through a two-photon transition. The absorptive vibrational component of the ultrafast optical nonlinearity grows in time, starting smaller than but quickly surpassing the electronic, rotational, and vibrational refractive components. The growth of the vibrational component results in a novel mechanism of third-harmonic generation, providing an additional two-photon excitation channel, fundamental + third harmonic. The original and emergent two-photon excitations drive the resonance exactly out of phase, causing spatial decay of the absorptive vibrational nonlinearity. This nearly eliminates two-photon vibrational absorption. Here we present simulations and analytical calculations demonstrating how these processes modify the ultrafast optical nonlinearity in air. The results reveal nonlinear optical phenomena unique to the LWIR regime of ultrashort pulse propagation in the atmosphere.

  3. Air Force electronic warfare evaluation simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Shepherd, Seth D.

    2001-08-01

    The Air Force Electronic Warfare Evaluation Simulator Infrared Countermeasures (IRCM) lab currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, LASERs, flares, and lamp-based jammer systems. The simulations of IR missiles in flight include real missile seeker hardware mounted in a six degree-of-freedom flight simulation table. The simulations of aircraft signatures and IR countermeasures are accomplished by using eight xenon arc lamps, located in 9' X 3' cylindrical housings, in the presentation foreground. A mirror system keeps the high intensity IR sources in the missile field of view. Range closure is simulated in the background by zooming in on the scene and in the foreground by separating and controlling the irises of the arc lamp sources for proper spatial and intensity characteristics. All relative motion and range closure is controlled by missile flyout software and aircraft flight-profile software models.

  4. Air Force Electronic Warfare Evaluation Simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Jackson, Hank D., II; Shepherd, Seth D.

    2004-08-01

    The Air Force Electronic Warfare Evaluation Simulator (AFEWES) Infrared Countermeasures (IRCM) test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, point-source flares and lamp- and LASER-based jammer systems. The simulations of IR missiles in flight include missile seeker hardware mounted on a six degree-of-freedom flight simulation table. This paper will focus on recent developments and upgrades to the AFEWES IR capability. In particular, current developments in IR scene generation/projection and efforts to optically combining the IR image produced by a resistive array with existing foreground lamp sources.

  5. Air Force electronic warfare evaluation simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Jackson, Hank D., II; Blair, Tommy L.; Ensor, Bruce A.; Deyo, Charles R.; Longbottom, Jeff A.; White, Jason C.

    2005-05-01

    The Air Force Electronic Warfare Evaluation Simulator (AFEWES) Infrared Countermeasures (IRCM) test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, point-source flares, and lamp- and LASER-based jammer systems. The simulations of IR missiles in flight include missile seeker hardware mounted on a six degree-of-freedom flight simulation table. This paper will focus on recent developments and upgrades to the AFEWES IR capability. In particular, current developments in IR scene generation/projection and efforts to optically combining the IR image produced by a resistive array with existing foreground lamp sources.

  6. Air Force electronic warfare evaluation simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Jackson, Hank D., II; Grauvogel, Nathanael L.; Blair, Tommy L.; Ensor, Bruce A.

    2006-05-01

    The Air Force Electronic Warfare Evaluation Simulator (AFEWES) infrared countermeasures (IRCM) test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, point-source flares, and lamp- and LASER-based jammer systems. The simulations of IR missiles in flight include missile seeker hardware mounted on a six degree-of-freedom flight simulation table. This paper will focus on recent developments and upgrades to the AFEWES IR capability. In particular, current developments in IR scene generation/projection and efforts to optically combine the IR image produced by a resistive array with existing foreground lamp sources.

  7. Air Force Electronic Warfare Evaluation Simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Jackson, Hank D., II; Blair, Tommy L.; Ensor, Bruce A.

    2007-04-01

    The Air Force Electronic Warfare Evaluation Simulator (AFEWES) Infrared Countermeasures (IRCM) test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, point-source flares and lamp- and LASER-based jammer systems. The simulations of IR missiles in flight include missile seeker hardware mounted on a six degree-of-freedom flight simulation table. This paper will focus on recent developments and upgrades to the AFEWES IR capability. In particular, current developments in IR scene generation/projection and efforts to optically combining the IR image produced by a resistive array with existing foreground lamp sources.

  8. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R. ); Schmalz, H. Thermal Surveys, Inc., Rockford, IL )

    1992-01-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

  9. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R.; Schmalz, H. |

    1992-11-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

  10. Improving Weather and Climate Prediction with the AIRS on Aqua

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.

    2009-01-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. Early in the mission, the AIRS instrument demonstrated its value to the weather forecasting community with better than 6 hours of improvement on the 5 day forecast. Now with over six years of consistent and stable data from AIRS, scientists are able to examine processes governing weather and climate and look at seasonal and interannual trends from the AIRS data with high statistical confidence. Naturally, long-term climate trends require a longer data set, but indications are that the Aqua spacecraft and the AIRS instrument should last beyond 2016. This paper briefly describes the AIRS products, reviews past science and weather accomplishments from AIRS data product users and highlights recent findings in these areas.

  11. Evidence of Convective Redistribution of Carbon Monoxide in Aura Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) Observations

    NASA Technical Reports Server (NTRS)

    Manyin, Michael; Douglass, Anne; Schoeberl, Mark

    2010-01-01

    Vertical convective transport is a key element of the tropospheric circulation. Convection lofts air from the boundary layer into the free troposphere, allowing surface emissions to travel much further, and altering the rate of chemical processes such as ozone production. This study uses satellite observations to focus on the convective transport of CO from the boundary layer to the mid and upper troposphere. Our hypothesis is that strong convection associated with high rain rate regions leads to a correlation between mid level and upper level CO amounts. We first test this hypothesis using the Global Modeling Initiative (GMI) chemistry and transport model. We find the correlation is robust and increases as the precipitation rate (the strength of convection) increases. We next examine three years of CO profiles from the Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) instruments aboard EOS Aura. Rain rates are taken from the Tropical Rainfall Measuring Mission (TRMM) 3B-42 multi-satellite product. Again we find a correlation between mid-level and upper tropospheric CO, which increases with rain rate. Our result shows the critical importance of tropical convection in coupling vertical levels of the troposphere in the transport of trace gases. The effect is seen most clearly in strong convective regions such as the Inter-tropical Convergence Zone.

  12. Advanced Remote-Sensing Imaging Emission Spectrometer (ARIES): AIRS Spectral Resolution with MODIS Spatial Resolution

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Chahine, Moustafa T.; Aumann, Hartmut H.; OCallaghan, Fred

    2006-01-01

    The Advanced Remote-sensing Imaging Emission Spectrometer (ARIES) will measure a wide range of earth quantities fundamental to the study of global climate change. It will build upon the success of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) instruments currently flying on the EOS Aqua Spacecraft. Both instruments are facility instruments for NASA providing data to thousands of scientists investigating land, ocean and atmospheric Earth System processes. ARIES will meet all the requirements of AIRS and MODIS in a single compact instrument, while providing the next-generation capability of improved spatial resolution for AIRS and improved spectral resolution for MODIS.

  13. Lessons Learned from Previous Space-Borne Sounders as a Guide to Future Sounder Development

    NASA Technical Reports Server (NTRS)

    Benson, Robert F.; Deshpande, Manohar D.; Farrell,William M.; Fung, Shing F.; Osherovich, Vladimir A.; Pfaff, Rovert E.; Rowland, Douglas E.; Adrian, Mark L.

    2008-01-01

    Space-borne radio sounding is considered to be the gold standard for electron-density (N(sub e)) measurements compared to other techniques even under low-density conditions, such as N(sub e) < 1/cu cm, when other techniques are known to experience difficulties. These reliable measurements are not restricted to in-situ N(sub e) determinations since a spaceborne sounder can provide vertical N(sub e) profiles (N(sub e)(h)) from the spacecraft altitude to the altitude of maximum N(sub e). Near-conjunction studies involving the International Satellites for Ionospheric Studies (ISIS) satellites in the topside ionosphere and Dynamics Explorer 2 (DE 2) near the altitude of the F-region peak density have verified that, even at the greatest distance from the sounder, the ISIS-derived N(sub e)(h) profiles agree with the DE-2 Langmuir-probe measurements to within about 30% over a density range of more than two decades. Space-borne sounders can also provide N(sub e) profiles along the magnetic-field B, by inverting echoes that are ducted along field-aligned irregularities (FAI), and can provide information about the terrain beneath the satellite by examining surface reflections in the frequency range above the ionospheric penetration frequency. Many nations have launched rocket and satellite radio sounders in geospace over more than 4 decades and there have been sounders on space-probes and in orbit around other planets. Here we will summarize some of the lessons learned from these accomplishments by analyzing data from radio sounders on the Alouette and ISIS satellites and the OEDIPUS and other rockets in the terrestrial ionosphere, the IMAGE satellite in the terrestrial magnetosphere, the Ulysses space probe in Jupiter's 10 plasma torus and the MARSIS satellite in orbit around Mars. The emphasis will be on information deduced concerning (1) fundamental plasma processes and gradients in N, and B in the vicinity of the sounders from sounder-stimulated plasma resonances and

  14. A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra

    NASA Technical Reports Server (NTRS)

    McMillian, W. Wallace; Strow, L. Larrabee; Revercomb, H.; Knuteson, R.; Thompson, A.

    2003-01-01

    This final report summarizes all research activities and publications undertaken as part of NASA Atmospheric Chemistry and Modeling Analysis Program (ACMAP) Grant NAG-1-2022, 'A Climatology of Tropospheric CO over the Central and Southeastern United States and the Southwestern Pacific Ocean Derived from Space, Air, and Ground-based Infrared Interferometer Spectra'. Major project accomplishments include: (1) analysis of more than 300,000 AERI spectra from the ARM SGP site yielding a 5-year (1998-2002) timeseries of CO retrievals from the Lamont, OK AERI; (2) development of a prototype CO profile retrieval algorithm for AERI spectra; (3) validation and publication of the first CO retrievals from the Scanning High-resolution Interferometer Sounder (SHIS); and (4) development of a prototype AERI tropospheric O3 retrieval algorithm. Compilation and publication of the 5-year Lamont, OK timeseries is underway including a new collaboration with scientists at the Lawrence Berkeley National Laboratory. Public access to this data will be provided upon article submission. A comprehensive CO analysis of the archive of HIS spectra of remains as the only originally proposed activity with little progress. The greatest challenge faced in this project was motivating the University of Wisconsin Co-Investigators to deliver their archived HIS and AERIOO data along with the requisite temperature and water vapor profiles in a timely manner. Part of the supplied HIS dataset from ASHOE may be analyzed as part of a Master s Thesis under a separate project. Our success with the SAFARI 2000 SHIS CO analysis demonstrates the utility of such aircraft remote sensing data given the proper support from the instrument investigators. In addition to the PI and Co-I s, personnel involved in this CO climatology project include one Post Doctoral Fellow, one Research Scientist, two graduate students, and two undergraduate students. A total of fifteen presentations regarding research related to this

  15. EVALUATION OF GAS CHROMATOGRAPHY/MATRIX ISOLATION INFRARED SPECTROMETRY FOR THE DETERMINATION OF SEMIVOLATILE ORGANIC COMPOUNDS IN AIR SAMPLE EXTRACTS

    EPA Science Inventory

    The capabilities of gas chromatography/matrix isolation-infrared (GC/MI-IR) spectrometry for determination of semivolatile organic compounds (SVOCs) in air sample extracts were evaluated. ystematic experiment, using xylene isomers as test compounds, were conducted to determine th...

  16. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  17. Satellite Sounder Data Assimilation for Improving Alaska Region Weather Forecast

    NASA Technical Reports Server (NTRS)

    Zhu, Jiang; Stevens, E.; Zavodsky, B. T.; Zhang, X.; Heinrichs, T.; Broderson, D.

    2014-01-01

    Data assimilation has been demonstrated very useful in improving both global and regional numerical weather prediction. Alaska has very coarser surface observation sites. On the other hand, it gets much more satellite overpass than lower 48 states. How to utilize satellite data to improve numerical prediction is one of hot topics among weather forecast community in Alaska. The Geographic Information Network of Alaska (GINA) at University of Alaska is conducting study on satellite data assimilation for WRF model. AIRS/CRIS sounder profile data are used to assimilate the initial condition for the customized regional WRF model (GINA-WRF model). Normalized standard deviation, RMSE, and correlation statistic analysis methods are applied to analyze one case of 48 hours forecasts and one month of 24-hour forecasts in order to evaluate the improvement of regional numerical model from Data assimilation. The final goal of the research is to provide improved real-time short-time forecast for Alaska regions.

  18. Performance status of the AIRS instrument thirteen years after launch

    NASA Astrophysics Data System (ADS)

    Elliott, Denis A.; Pagano, Thomas S.; Aumann, Hartmut H.; Broberg, Steven E.

    2015-09-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral infrared instrument on the EOS Aqua Spacecraft, launched on May 4, 2002. AIRS has 2378 infrared channels ranging from 3.7 μm to 15.4 μm and a 13.5 km footprint at nadir. AIRS is a "facility" instrument developed by NASA as an experimental demonstration of advanced technology for remote sensing and the benefits of high resolution infrared spectra to science investigations. AIRS, in conjunction with the Advanced Microwave Sounding Unit (AMSU), produces temperature profiles with 1K/km accuracy on a global scale, as well as water vapor profiles and trace gas amounts for CO2 , CO, SO2 , O3 and CH4. AIRS data are used for weather forecasting, climate process studies and validating climate models. The AIRS instrument has far exceeded its required design life of 5 years, with nearly 13 years of routine science operations that began on August 31, 2002. While the instrument has performed exceptionally well, with little sign of wear, the AIRS Project continues to monitor and maintain the health of AIRS, characterize its behavior and improve performance where possible. Radiometric stability has been monitored and trending shows better than 16 mK/year stability. Spectral calibration stability is better than 1 ppm/year. At this time we expect the AIRS to continue to perform well into the next decade. This paper contains updates to previous instrument status reports, with emphasis on the last three years.

  19. AIRS/AMSU-A/HSB Data On-demand Subsetting and Visualization Services at NASA GES DISC DAAC

    NASA Astrophysics Data System (ADS)

    Li, J.; Cho, S.; Sun, D.; Qin, J.; Sharma, A. K.

    2002-12-01

    The Atmospheric Infrared Sounder (AIRS) is a high-resolution infrared sounder closely coupled with AMSU-A (Advanced Microwave Sounding Unit-A) and HSB (Humidity Sounder for Brazil) on EOS Aqua spacecraft launched on May 4, 2002. The data products from AIRS/AMSU-A/HSB will be archived and distributed at the Goddard Distributed Active Archive Center (GDAAC) located in the NASA Goddard Earth Sciences Data and Information Services Center (GES DAAC). The ADDST is developing tools to read, visualize, analyze and reformat AIRS/AMSU-A/HSB data. The web-based AIRS on-the-fly/on-demand subsetter will be available to perform channel/variable subsetting and restructuring for Level1B (Calibrated Radiances) and Level2 (Atmospheric Retrievals) data products. One can narrow down criteria to subset data files with desired channels and variables and then download the subsetted file. AIRS QuickLook allows users to view AIRS/HSB/AMSU Level-1B data online for a specific channel prior to ordering or downloading data. Global map is also provided along with image to show geographic coverage of the granule and flight direction of the spacecraft. The Atmospheric Dynamics Data Support Team (ADDST) at the GES DISC/DAAC is providing various services to assist users in understanding, accessing, and using AIRS data product. Information on AIRS data and data analysis tools can be found at AIRS data support informational web site (http://daac.gsfc.nasa.gov/atmodyn/airs/ ) that provides access to various technical online documents, such as, readmes, user's guides, instrument guides, images from AIRS/AMSU-A/HSB data, product search and ordering interfaces, HDF-EOS format information, format conversion software, online data analysis tools, other AIRS related web links and more. Other data support services provided by the ADDST are assist with data mining, helpdesk for user questions on data and information, data ordering, and educational resources.

  20. VAS demonstration: (VISSR Atmospheric Sounder) description

    NASA Technical Reports Server (NTRS)

    Montgomery, H. E.; Uccellini, L. W.

    1985-01-01

    The VAS Demonstration (VISSR Atmospheric Sounder) is a project designed to evaluate the VAS instrument as a remote sensor of the Earth's atmosphere and surface. This report describes the instrument and ground processing system, the instrument performance, the valiation as a temperature and moisture profiler compared with ground truth and other satellites, and assesses its performance as a valuable meteorological tool. The report also addresses the availability of data for scientific research.

  1. Topside Ionospheric Sounder for CubeSats

    NASA Astrophysics Data System (ADS)

    Swenson, C.; Pratt, J.; Fish, C. S.; Winkler, C.; Pilinski, M.; Azeem, I.; Crowley, G.; Jeppesen, M.; Martineau, R.

    2014-12-01

    This presentation will outline the design of a Topside Ionospheric Sounder (TIS) for CubeSats. In the same way that an ionosonde measures the ionospheric profile from the ground, a Topside Sounder measures the ionospheric profile from a location above the F-region peak. The TIS will address the need for increased space situational awareness and environmental monitoring by estimating electron density profiles in the topside of the ionosphere. The TIS will measure topside electron density profiles for plasma frequencies ranging from 0.89 MHz to 28.4 MHz below the satellite altitude. The precision of the measurement will be 5% or 10,000 p/cm^3. The TIS average power consumption will be below 10 W and a mass of less than 10 kg, so it is appropriate for a 6U Cubesat (or multiple of that size). The sounder will operate via a transmitted frequency sweep across the desired plasma frequencies which, upon reception, can be differenced to determine range and density information of the topside ionosphere. The velocity of the spacecraft necessitates careful balancing of range resolution and frequency knowledge requirements as well as novel processing techniques to correctly associate the return signal with the correct plasma frequency. TIS is being designed to provide a low cost, low mass spacecraft that can provide accurate topside profiles of the ionospheric electron density in order to further understanding of ionospheric structure and dynamic processes in the ionosphere.

  2. Hurricane Isabel, AIRS Infrared and SeaWinds Scatterometer Data Combined

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    These two images show Hurricane Isabel as viewed by AIRS and each of the two SeaWinds scatterometers on the ADEOS-2 and QuikScat satellites, all JPL-managed experiments. AIRS data are used to create global three-dimensional maps of temperature, humidity and clouds, while scatterometers measure surface wind speed and direction.

    Figure 1 shows Isabel on September 13, 2003, when it was a Category 5 storm threatening the Caribbean and southern United States. At the time Isabel was the strongest Atlantic storm since hurricane Mitch killed thousands in central America in 1997. The red vectors in the image show Isabel's surface winds as measured by SeaWinds on ADEOS-2, and the background colors show the temperature of clouds and surface, as viewed in the infrared by AIRS. The hurricane's powerful swirling winds are apparent. These winds circle the hurricane's eye, seen as the red dot near the middle top of the image. Light blue areas shows adjacent cold clouds tops associated with strong thunderstorms embedded within the storm.

    Figure 2 shows Isabel as it approached landfall on the outer banks of North Carolina on September 18. The hurricane weakened in the five days since the earlier image was observed, as indicated by a less clearly defined eye. Nevertheless, it was still a powerful storm. The winds blowing onshore north of the eye knocked over trees, blew roofs off buildings, and drove large waves that breached the coastal barrier islands in many places. Water, transportation and power are still not fully restored to many of the areas in the image. The winds apparently blowing away from the eye of the storm are an artifact of one of the hurricane's other destructive phenomena: rain. The darkest blue clouds observed by AIRS show the most intense thunderstorms, and hence the heaviest rains. Hard rain fools the the SeaWinds on Quik

  3. Performance of greenhouse gas profiling by infrared-laser and microwave occultation in cloudy air

    NASA Astrophysics Data System (ADS)

    Proschek, V.; Kirchengast, G.; Emde, C.; Schweitzer, S.

    2012-12-01

    ACCURATE is a proposed future satellite mission enabling simultaneous measurements of greenhouse gases (GHGs), wind and thermodynamic variables from Low Earth Orbit (LEO). The measurement principle is a combination of LEO-LEO infrared-laser occultation (LIO) and microwave occultation (LMO), the LMIO method, where the LIO signals are very sensitive to clouds. The GHG retrieval will therefore be strongly influenced by clouds in parts of the troposphere. The IR-laser signals, at wavelengths within 2--2.5μ m, are chosen to measure six GHGs (H2O, CO2, CH4, N2O, O3, CO; incl.~key isotopes 13CO2, C18OO, HDO). The LMO signals enable to co-measure the thermodynamic variables. In this presentation we introduce the algorithm to retrieve GHG profiles under cloudy-air conditions by using quasi-realistic forward simulations, including also influence of Rayleigh scattering, scintillations and aerosols. Data from CALIPSO--Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations--with highest vertical resolution of about 60 m and horizontal resolution of about 330 m were used for simulation of clouds. The IR-laser signals consist for each GHG of a GHG-sensitive and a close-by reference signal. The key process, ``differencing'' of these two signals, removes the atmospheric ``broadband'' effects, resulting in a pure GHG transmission profile. Very thin ice clouds, like sub-visible cirrus, are fairly transparent to the IR-laser signals, thicker and liquid water clouds block the signals. The reference signal is used to produce a cloud layering profile from zero to blocking clouds and is smoothed in a preprocess to suppress scintillations. Sufficiently small gaps, of width <2 km in the cloud layering profile, are found to enable a decent retrieval of entire GHG profiles over the UTLS under broken cloudiness and are therefore bridged by interpolation. Otherwise in case of essentially continuous cloudiness the profiles are found to terminate at cloud top level. The accuracy of

  4. Processing AIRS Scientific Data Through Level 3

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie; Oliphant, Robert; Manning, Evan

    2010-01-01

    The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA's Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: Initial Processing of Infrared Spectral Data (NPO-35243), Vol. 28, No. 11 (November 2004), page 39. In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multiday products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.

  5. The Stratospheric Wind Ingrared Limb Sounder: Investigation of atmospheric dynamics and transport from Eos

    NASA Technical Reports Server (NTRS)

    Mccleese, D. J.

    1992-01-01

    The Stratospheric Wind Infrared Limb Sounder (SWIRLS) is one of the instruments in the atmospheric sounder package to be flown by NASA on the Earth Observing System (EOS) B platform in the late 1990's. SWIRLS is designed to measure the horizontal vector wind field, atmospheric temperature, and the abundances and distributions of ozone and nitrous oxide in the middle atmosphere. These measurements will constitute a dynamical climatology of the stratosphere covering time scales ranging from diurnal to interannual. In addition, the SWIRLS investigation will quantify the physical mechanisms responsible for the structure and variations of stratospheric circulation and temperature fields, including the transport of species, particularly ozone, heat and momentum. Existing data sets lack the combination of accuracy, global and temporal coverage, spatial resoultion and simultaneity required to distinguish unambiguosly between the roles of dynamical and chemical processes in determining the current distribution of ozone and its evolution in the future. The measurement objectives, measurement approach, and instrumentation of SWIRLS is described.

  6. Development of the Advanced Technology Microwave Sounder (ATMS) for NPOESS C1

    NASA Astrophysics Data System (ADS)

    Brann, C.; Kunkee, D.

    2008-12-01

    The National Polar-orbiting Operational Environmental Satellite System's Advanced Technology Microwave Sounder (ATMS) is planned for flight on the first NPOESS mission (C1) in 2013. The C1 ATMS will be the second instrument of the ATMS series and will provide along with the companion Cross-track Infrared Sounder (CrIS), atmospheric temperature and moisture profiles for NPOESS. The first flight of the ATMS is scheduled in 2010 on the NPOESS Preparatory Project (NPP) satellite, which is an early instrument risk reduction component of the NPOESS mission. This poster will focus on the development of the ATMS for C1 including aspects of the sensor calibration, antenna beam and RF characteristics and scanning. New design aspects of the C1 ATMS, required primarily by parts obsolescence, will also be addressed in this poster.

  7. Hyperspectral Microwave Atmospheric Sounder (HyMAS) Architecture and Design Accommodations

    NASA Technical Reports Server (NTRS)

    Hilliard, Lawrence; Racette, Paul; Blackwell, William; Galbraith, Christopher; Thompson, Erik

    2013-01-01

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term "hyperspectral microwave" is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth s atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4-9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the scan head computer

  8. Hyperspectral Microwave Atmospheric Sounder (HyMAS) architecture and design accommodations

    NASA Astrophysics Data System (ADS)

    Hilliard, L.; Racette, P.; Blackwell, W.; Galbraith, C.; Thompson, E.

    The Hyperspectral Microwave Atmospheric Sounder (HyMAS) is being developed at Lincoln Laboratories and accommodated by the Goddard Space Flight Center for a flight opportunity on a NASA research aircraft. The term “ hyperspectral microwave” is used to indicate an all-weather sounding that performs equivalent to hyperspectral infrared sounders in clear air with vertical resolution of approximately 1 km. Deploying the HyMAS equipped scanhead with the existing Conical Scanning Microwave Imaging Radiometer (CoSMIR) shortens the path to a flight demonstration. Hyperspectral microwave is achieved through the use of independent RF antennas that sample the volume of the Earth's atmosphere through various levels of frequencies, thereby producing a set of dense, spaced vertical weighting functions. The simulations proposed for HyMAS 118/183-GHz system should yield surface precipitation rate and water path retrievals for small hail, soft hail, or snow pellets, snow, rainwater, etc. with accuracies comparable to those of the Advanced Technology Microwave Sounder. Further improvements in retrieval methodology (for example, polarization exploitation) are expected. The CoSMIR instrument is a packaging concept re-used on HyMAS to ease the integration features of the scanhead. The HyMAS scanhead will include an ultra-compact Intermediate Frequency Processor (IFP) module that is mounted inside the door to improve thermal management. The IFP is fabricated with materials made of Low-Temperature Co-fired Ceramic (LTCC) technology integrated with detectors, amplifiers, A/D conversion and data aggregation. The IFP will put out 52 channels of 16 bit data comprised of 4 - 9 channel data streams for temperature profiles and 2-8 channel streams for water vapor. With the limited volume of the existing CoSMIR scanhead and new HyMAS front end components, the HyMAS team at Goddard began preliminary layout work inside the new drum. Importing and re-using models of the shell, the s- an head

  9. Middle Atmosphere Sounder and Thermal Emission Radiometer - Master

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Scott, D. K.; Esplin, R. W.; Bailey, S. M.; Randall, C. E.

    2014-12-01

    The Middle Atmosphere Sounder and Thermal Emission Radiometer (MASTER) instrument is an advanced infrared limb-scanning instrument designed to measure the thermal structure, chemical composition, and energy balance from the stratosphere to the lower thermosphere. MASTER builds on NASA's long and successful heritage of infrared limb scanners including the LIMS, HIRDLS, and SABER instruments. MASTER has exceptional radiometric sensitivity with a more efficient, compact, and lightweight design. An updated focal plane enables critical new science in the areas of the carbon budget closure, geomagnetically-driven ozone destruction, and auroral energy deposition, while virtually eliminating out of band contributions via dual filtering. MASTER will continue the SABER-TIMED and EOS-Aura records of temperature, lower stratospheric water vapor, ozone, methane, and thermospheric cooling by nitric oxide and carbon dioxide. MASTER's size and mass are specifically designed to allow flexibility in the choice of small satellite buses and low cost launch vehicles. The expanded focal plane enables a choice of channels applicable to science objectives in NASA's Earth Science and Heliophysics enterprises. Due to the long and successful heritage the MASTER instrument is at an exceptionally high technology readiness level. No new technologies are required to build the MASTER flight instrument.

  10. Ultrabroadband conical emission generated from the ultraviolet up to the far-infrared during the optical filamentation in air.

    PubMed

    Théberge, Francis; Châteauneuf, Marc; Ross, Vincent; Mathieu, Pierre; Dubois, Jacques

    2008-11-01

    Ultraviolet and infrared conical emissions were observed during the filamentation in air of powerful femtosecond laser pulses produced by a portable terawatt laser system. The broadband spectrum was measured from 200 nm up to 14 microm and covered the complete optical transmission window of the atmosphere. The angularly resolved spectrum showed some X-wave structure across the frequency range analyzed. However, we demonstrated that the strong conical emission observed in the mid- and far-infrared is mainly owing to the four-wave mixing between the pump pulse and its blueshifted conical emission. PMID:18978905

  11. The roles of vibration analysis and infrared thermography in monitoring air-handling equipment

    NASA Astrophysics Data System (ADS)

    Wurzbach, Richard N.

    2003-04-01

    Industrial and commercial building equipment maintenance has not historically been targeted for implementation of PdM programs. The focus instead has been on manufacturing, aerospace and energy industries where production interruption has significant cost implications. As cost-effectiveness becomes more pervasive in corporate culture, even office space and labor activities housed in large facilities are being scrutinized for cost-cutting measures. When the maintenance costs for these facilities are reviewed, PdM can be considered for improving the reliability of the building temperature regulation, and reduction of maintenance repair costs. An optimized program to direct maintenance resources toward a cost effective and pro-active management of the facility can result in reduced operating budgets, and greater occupant satisfaction. A large majority of the significant rotating machinery in a large building environment are belt-driven air handling units. These machines are often poorly designed or utilized within the facility. As a result, the maintenance staff typically find themselves scrambling to replace belts and bearings, going from one failure to another. Instead of the reactive-mode maintenance, some progressive and critical institutions are adopting predictive and proactive technologies of infrared thermography and vibration analysis. Together, these technologies can be used to identify design and installation problems, that when corrected, significantly reduce maintenance and increase reliability. For critical building use, such as laboratories, research facilities, and other high value non-industrial settings, the cost-benefits of more reliable machinery can contribute significantly to the operational success.

  12. High Resolution Infrared Radiation Sounder/mod 2 (HIRS/2)

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1979-01-01

    The HIRS/2 is provided for the TIROS-N series of operational meteorological satellites. The instrument features 20 spectral channels, including visible (.7 micron), shortwave (3.7 to 4.6 micron), and longwave (6.7 to 15 micron). Radiance data aids determination of vertical temperature profiles, water vapor, and ozone distribution. System performance and test results are described.

  13. Long-wave infrared 1 × 2 MMI based on air-gap beneath silicon rib waveguides.

    PubMed

    Wei, Yuxin; Li, Guoyi; Hao, Yinlei; Li, Yubo; Yang, Jianyi; Wang, Minghua; Jiang, Xiaoqing

    2011-08-15

    The undercut long-wave infrared (LWIR) waveguide components with air-gap beneath are analyzed and fabricated on the Si-wafer with simple manufacturing process. A 1 × 2 multimode interference (MMI) splitter based on this structure is presented and measured under the 10.6 μm wavelength experimental setup. The uniformity of the MMI fabricated is 0.76 dB. The relationship among the output power, slab thickness and air-gap width is also fully discussed. Furthermore, undercut straight waveguides based on SOI platform are fabricated for propagation loss evaluation. Ways to reduce the loss are discussed either. PMID:21934942

  14. Laser Atmospheric Wind Sounder (LAWS) performance analysis

    NASA Technical Reports Server (NTRS)

    Kenyon, D.; Petheram, J.

    1991-01-01

    The science objectives of the NASA's Laser Atmospheric Sounder (LAWS) are discussed, and results of the performance analysis of the LAWS system are presented together with the instrument configuration used for these performance analyses. The results of analyses show that the science requirements for the wind-velocity accuracies of m/sec in the lower troposphere and 5 m/sec in the upper troposphere will be met by the present design of the LAWS system. The paper presents the performance estimates of the LAWS in terms of the global coverage, spatial resolution, signal-to-noise ratio, line-of-sight velocity error, and horizontal inversion accuracy.

  15. AIRS Ozone Burden During Antarctic Winter: Time Series from 8/1/2005 to 9/30/2005

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of AIRS Ozone Burden During Antarctic Winter

    AIRS provides a daily global 3-dimensional view of Earth's ozone layer. Since AIRS observes in the thermal infrared spectral range, it also allows scientists to view from space the Antarctic ozone hole for the first time continuously during polar winter. This image sequence captures the intensification of the annual ozone hole in the Antarctic Polar Vortex.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  16. View to the south with the Two Sounder Antennas on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the south with the Two Sounder Antennas on the left - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Four Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  17. Inter-Comparison of GOES-8 Imager and Sounder Skin Temperature Retrievals

    NASA Technical Reports Server (NTRS)

    Haines, Stephanie L.; Suggs, Ronnie J.; Jedlovec, Gary J.; Arnold, James E. (Technical Monitor)

    2001-01-01

    Skin temperature (ST) retrievals derived from geostationary satellite observations have both high temporal and spatial resolutions and are therefore useful for applications such as assimilation into mesoscale forecast models, nowcasting, and diagnostic studies. Our retrieval method uses a Physical Split Window technique requiring at least two channels within the longwave infrared window. On current GOES satellites, including GOES-11, there are two Imager channels within the required spectral interval. However, beginning with the GOES-M satellite the 12-um channel will be removed, leaving only one longwave channel. The Sounder instrument will continue to have three channels within the longwave window, and therefore ST retrievals will be derived from Sounder measurements. This research compares retrievals from the two instruments and evaluates the effects of the spatial resolution and sensor calibration differences on the retrievals. Both Imager and Sounder retrievals are compared to ground-truth data to evaluate the overall accuracy of the technique. An analysis of GOES-8 and GOES-11 intercomparisons is also presented.

  18. A comparison of measured radiances from AIRS and HIRS across different cloud types

    NASA Astrophysics Data System (ADS)

    Schreier, M. M.; Kahn, B. H.; Staten, P.

    2015-12-01

    The observation of Earth's atmosphere with passive remote sensing instruments is ongoing for decades and resulting in a long-term global dataset. Two prominent examples are operational satellite platforms from the National Oceanic and Atmospheric Administration (NOAA) or research platforms like NASA's Earth Observing System (EOS). The observed spectral ranges of these observations are often similar among the different platforms, but have large differences when it comes to resolution, accuracy and quality control. Our approach is to combine different kinds of instruments at the pixel-scale to improve the characterization of infrared radiances. We focus on data from the High-resolution Infrared Radiation Sounder (HIRS) and compare the observations to radiances from the Atmospheric Infrared Sounder (AIRS) on Aqua. The high spectral resolution of AIRS is used to characterize and possibly recalibrate the observed radiances from HIRS. Our approach is unique in that we use additional information from other passive instruments on the same platforms including the Advanced Very High Resolution Radiometer (AVHRR) and the MODerate resolution Imaging Spectroradiometer (MODIS). We will present comparisons of radiances from HIRS and AIRS within different types of clouds that are determined from the imagers. In this way, we can analyze and select the most homogeneous conditions for radiance comparisons and a possible re-calibration of HIRS. We hope to achieve a cloud-type-dependent calibration and quality control for HIRS, which can be extrapolated into the past via inter-calibration of the different HIRS instruments beyond the time of AIRS.

  19. Topside sounder observations of equatorial bubbles

    NASA Technical Reports Server (NTRS)

    Dyson, P. L.; Benson, R. F.

    1978-01-01

    Large scale regions of depleted equatorial ionospheric plasma, called equatorial bubbles, are investigated using topside sounder data. The sounder's unique remote measuring capability enables the magnetic field-aligned nature of the bubbles to be investigated. A search of all available Alouette 2 and ISIS 1 ionograms during nighttime perigee passes near the magnetic equator has revealed a variety of echo signatures associated with bubbles. In addition to a sudden drop in electron density, these signatures usually include in situ spread F and ducted traces. The ducted traces have been used to determine the electron density distribution and to infer changes in ion composition along the magnetic field line within the duct associated with the bubble. In some cases it can be determined that the bubble is asymmetric with respect to the magnetic equator. Even though such features require 3 dimensional models for their explanation, the great field-aligned extent of the bubbles (relative to their cross section) suggests that current theories, which ignore variations along the magnetic field, are still applicable.

  20. Eight Year Climatologies from Observational (AIRS) and Model (MERRA) Data

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas; Savtchenko, Andrey; Won, Young-In; Theobalk, Mike; Vollmer, Bruce; Manning, Evan; Smith, Peter; Ostrenga, Dana; Leptoukh, Greg

    2010-01-01

    We examine climatologies derived from eight years of temperature, water vapor, cloud, and trace gas observations made by the Atmospheric Infrared Sounder (AIRS) instrument flying on the Aqua satellite and compare them to similar climatologies constructed with data from a global assimilation model, the Modern Era Retrospective-Analysis for Research and Applications (MERRA). We use the AIRS climatologies to examine anomalies and trends in the AIRS data record. Since sampling can be an issue for infrared satellites in low earth orbit, we also use the MERRA data to examine the AIRS sampling biases. By sampling the MERRA data at the AIRS space-time locations both with and without the AIRS quality control we estimate the sampling bias of the AIRS climatology and the atmospheric conditions where AIRS has a lower sampling rate. While the AIRS temperature and water vapor sampling biases are small at low latitudes, they can be more than a few degrees in temperature or 10 percent in water vapor at higher latitudes. The largest sampling biases are over desert. The AIRS and MERRA data are available from the Goddard Earth Sciences Data and Information Services Center (GES DISC). The AIRS climatologies we used are available for analysis with the GIOVANNI data exploration tool. (see, http://disc.gsfc.nasa.gov).

  1. Microwave Limb Sounder/El Nino Watch - December, 1997

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image shows differences in atmospheric water vapor relative to a normal (average) year in the Earth's upper troposphere about 10 kilometers (6 miles) above the surface. The measurements were taken by the Microwave Limb Sounder (MLS) instrument aboard NASA's Upper Atmosphere Research Satellite (UARS). These data, collected in late December 1997, show higher than normal levels of water vapor (red) over the central and eastern Pacific which indicates the presence of an El Nino condition. At the same time, the western Pacific (blue) is much drier than normal. The unusually moist air above the central and eastern Pacific is a consequence of the much warmer-than-normal ocean waters which occur during El Nino. Warmer water evaporates at a higher rate and the resulting warm moist air rises and forms tall cloud towers. In the tropics, the warm water and the resulting tall cloud towers typically produce large amounts of rain. These data show significant increases in the amount of atmospheric moisture off the coast of Peru and Ecuador since measurements were made in November 1997. The maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal and these high ocean temperatures are likely responsible for an increase in evaporation and the subsequent rise in humidity.

  2. Physical Retrieval of Surface Emissivity Spectrum from Hyperspectral Infrared Radiances

    NASA Technical Reports Server (NTRS)

    Li, Jun; Weisz, Elisabeth; Zhou, Daniel K.

    2007-01-01

    Retrieval of temperature, moisture profiles and surface skin temperature from hyperspectral infrared (IR) radiances requires spectral information about the surface emissivity. Using constant or inaccurate surface emissivities typically results in large retrieval errors, particularly over semi-arid or arid areas where the variation in emissivity spectrum is large both spectrally and spatially. In this study, a physically based algorithm has been developed to retrieve a hyperspectral IR emissivity spectrum simultaneously with the temperature and moisture profiles, as well as the surface skin temperature. To make the solution stable and efficient, the hyperspectral emissivity spectrum is represented by eigenvectors, derived from the laboratory measured hyperspectral emissivity database, in the retrieval process. Experience with AIRS (Atmospheric InfraRed Sounder) radiances shows that a simultaneous retrieval of the emissivity spectrum and the sounding improves the surface skin temperature as well as temperature and moisture profiles, particularly in the near surface layer.

  3. The Advanced Technology Microwave Sounder (ATMS): First Year On-Orbit

    NASA Astrophysics Data System (ADS)

    Kim, E. J.; Lyu, C.; Blackwell, W. J.; Leslie, V.; Baker, N.; Mo, T.; Sun, N.; Bi, L.; Anderson, K.; Landrum, M.; De Amici, G.; Gu, D.; Foo, A.; Ibrahim, W.; Robinson, K.

    2012-12-01

    The Advanced Technology Microwave Sounder (ATMS) is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. ATMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first ATMS was launched October 28, 2011 on board the Suomi-NPOESS Preparatory Project (S-NPP) satellite and has just finished its first year on orbit. Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction (NWP) models; and ATMS, when combined with the Cross-track Infrared Sounder (CrIS), forms the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The microwave soundings help meet NWP sounding requirements under cloudy sky conditions and provide key profile information near the surface. Designed & built by Aerojet Corporation in Azusa, California, (now Northrop Grumman Electronic Systems), ATMS has 22 channels spanning 23—183 GHz, closely following the channel set of the MSU, AMSU-A1 and A2, AMSU-B, Microwave Humidity Sounder (MHS), and Humidity Sounder for Brazil (HSB). It continues their cross-track scanning geometry, but for the first time, provides Nyquist sample spacing. All this is accomplished with approximately one quarter the volume, one half the mass, and one half the power of the three AMSUs. A summary description of the ATMS design will be presented. Post-launch calibration/validation activities include geolocation determination, radiometric calibration using the on-board warm targets and cold space views, simultaneous observations by microwave sounders on other satellites, comparison vs. pre-launch thermovacuum test performance; observations vs. atmospheric model predicted radiances, and comparisons of soundings vs. radiosondes. Brief descriptions of these

  4. Sulfur Dioxide Plume from Mt. Etna Eruption 2002 as Detected with AIRS Data

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Mt. Etna, a volcano on the island of Sicily, erupted on October 26, 2002. Preliminary analysis of data taken by the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on October 28 shows the instrument can provide an excellent means to study the evolution and structure of the sulfur dioxide plume emitted from volcanoes. These data also demonstrate that AIRS can be used to obtain the total mass of sulfur dioxide injected into the atmosphere during a volcanic event, information that may help us to better understand these dangerous natural occurrences in the future.

    The image clearly shows the sulfur dioxide plume. This image was created by comparing data taken at two different frequencies, or channels, and creating one image that highlights the differences between these two channels. Both channels are sensitive to water vapor, but one of the channels is also sensitive to sulfur dioxide. By subtracting out the common water vapor signal in both channels, the sulfur dioxide feature remains and shows up as an enhancement in the difference image.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  5. Error Consistency Analysis Scheme for Infrared Ultraspectral Sounding Retrieval Error Budget Estimation

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Strow, Larry, L.

    2013-01-01

    Great effort has been devoted towards validating geophysical parameters retrieved from ultraspectral infrared radiances obtained from satellite remote sensors. An error consistency analysis scheme (ECAS), utilizing fast radiative transfer model (RTM) forward and inverse calculations, has been developed to estimate the error budget in terms of mean difference and standard deviation of error in both spectral radiance and retrieval domains. The retrieval error is assessed through ECAS without relying on other independent measurements such as radiosonde data. ECAS establishes a link between the accuracies of radiances and retrieved geophysical parameters. ECAS can be applied to measurements from any ultraspectral instrument and any retrieval scheme with its associated RTM. In this manuscript, ECAS is described and demonstrated with measurements from the MetOp-A satellite Infrared Atmospheric Sounding Interferometer (IASI). This scheme can be used together with other validation methodologies to give a more definitive characterization of the error and/or uncertainty of geophysical parameters retrieved from ultraspectral radiances observed from current and future satellite remote sensors such as IASI, the Atmospheric Infrared Sounder (AIRS), and the Cross-track Infrared Sounder (CrIS).

  6. Evaluation of the Impact of AIRS Radiance and Profile Data Assimilation in Partly Cloudy Regions

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

    2013-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of a long-term series of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

  7. Global Carbon Monoxide Products from Combined AIRS, TES and MLS Measurements on A-Train Satellites

    NASA Technical Reports Server (NTRS)

    Warner, Juying X.; Yang, R.; Wei, Z.; Carminati, F.; Tangborn, A.; Sun, Z.; Lahoz, W.; Attie, J. L.; El Amraoui, L.; Duncan, B.

    2014-01-01

    This study tests a novel methodology to add value to satellite data sets. This methodology, data fusion, is similar to data assimilation, except that the background modelbased field is replaced by a satellite data set, in this case AIRS (Atmospheric Infrared Sounder) carbon monoxide (CO) measurements. The observational information comes from CO measurements with lower spatial coverage than AIRS, namely, from TES (Tropospheric Emission Spectrometer) and MLS (Microwave Limb Sounder). We show that combining these data sets with data fusion uses the higher spectral resolution of TES to extend AIRS CO observational sensitivity to the lower troposphere, a region especially important for air quality studies. We also show that combined CO measurements from AIRS and MLS provide enhanced information in the UTLS (upper troposphere/lower stratosphere) region compared to each product individually. The combined AIRS-TES and AIRS-MLS CO products are validated against DACOM (differential absorption mid-IR diode laser spectrometer) in situ CO measurements from the INTEX-B (Intercontinental Chemical Transport Experiment: MILAGRO and Pacific phases) field campaign and in situ data from HIPPO (HIAPER Pole-to-Pole Observations) flights. The data fusion results show improved sensitivities in the lower and upper troposphere (20-30% and above 20%, respectively) as compared with AIRS-only version 5 CO retrievals, and improved daily coverage compared with TES and MLS CO data.

  8. Intercomparison of stratospheric gravity wave observations with AIRS and IASI

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Alexander, M. J.; Clerbaux, C.; Grimsdell, A. W.; Meyer, C. I.; Rößler, T.; Tournier, B.

    2014-12-01

    Gravity waves are an important driver for the atmospheric circulation and have substantial impact on weather and climate. Satellite instruments offer excellent opportunities to study gravity waves on a global scale. This study focuses on observations from the Atmospheric Infrared Sounder (AIRS) onboard the National Aeronautics and Space Administration Aqua satellite and the Infrared Atmospheric Sounding Interferometer (IASI) onboard the European MetOp satellites. The main aim of this study is an intercomparison of stratospheric gravity wave observations of both instruments. In particular, we analyzed AIRS and IASI 4.3 μm brightness temperature measurements, which directly relate to stratospheric temperature. Three case studies showed that AIRS and IASI provide a clear and consistent picture of the temporal development of individual gravity wave events. Statistical comparisons based on a 5-year period of measurements (2008-2012) showed similar spatial and temporal patterns of gravity wave activity. However, the statistical comparisons also revealed systematic differences of variances between AIRS and IASI that we attribute to the different spatial measurement characteristics of both instruments. We also found differences between day- and nighttime data that are partly due to the local time variations of the gravity wave sources. While AIRS has been used successfully in many previous gravity wave studies, IASI data are applied here for the first time for that purpose. Our study shows that gravity wave observations from different hyperspectral infrared sounders such as AIRS and IASI can be directly related to each other, if instrument-specific characteristics such as different noise levels and spatial resolution and sampling are carefully considered. The ability to combine observations from different satellites provides an opportunity to create a long-term record, which is an exciting prospect for future climatological studies of stratospheric gravity wave activity.

  9. Determination of methyl radical concentrations in a methane/air flame by infrared cavity ringdown laser absorption spectroscopy

    SciTech Connect

    Scherer, J.J.; Aniolek, K.W.; Cernansky, N.P.; Rakestraw, D.J.

    1997-10-01

    Infrared cavity ringdown laser absorption spectroscopy (IR-CRLAS) is employed to determine absolute methyl radical concentrations in a 37.5 Torr laminar methane/air flame. IR-CRLAS rovibrational absorption spectra of the {nu}{sub 3} fundamental band system near 3200thinspcm{sup {minus}1} are combined with N{sub 2}-CARS temperature measurements to obtain methyl radical concentrations as a function of height above the burner surface. These data are compared with flame chemistry simulations under both stoichiometric and rich flame conditions. Issues regarding the applicability of IR-CRLAS for combustion studies are discussed, including the uncertainties present for the specific case of methyl radical. These IR-CRLAS measurements indicate the ability to monitor reactants, intermediates, and products within a narrow spectral window, and, to our knowledge, constitute the first infrared detection of a polyatomic radical in a flame. {copyright} {ital 1997 American Institute of Physics.}

  10. RAWS: The spaceborne radar wind sounder

    NASA Astrophysics Data System (ADS)

    Moore, Richard K.

    1991-09-01

    The concept of the Radar Wind Sounder (RAWS) is discussed. The goals of the RAWS is to estimate the following three qualities: the echo power, to determine rain rate and surface wind velocity; the mean Doppler frequency, to determine the wind velocity in hydrometers; and the spread of the Doppler frequency, to determine the turbulent spread of the wind velocity. Researchers made significant progress during the first year. The feasibility of the concept seems certain. Studies indicate that a reasonably sized system can measure in the presence of ice clouds and dense water clouds. No sensitivity problems exist in rainy environments. More research is needed on the application of the radar to the measurement of rain rates and winds at the sea surface.

  11. Microwave limb sounder for stratospheric measurements

    NASA Astrophysics Data System (ADS)

    Waters, J. W.; Hardy, J. C.; Jarnot, R. F.; Pickett, H. M.; Zimmerman, P.

    1985-06-01

    The balloon-borne Microwave Limb Sounder (BMLS) measures atmospheric thermal emission from millimeter wavelength spectral lines to determine vertical profiles of stratospheric species. The instrument flown to data operates at 205 BHz to measure ClO, O3, and H2O2. A 63 GHz radiometer is added to test the technique for determining tangent point pressure from the MLS experiment on the Upper Atmosphere Research Satellite (UARS). Many additional species is also measured by the BLMS. A radiometer at 270 GHz would provide measurements of HO2, NO2, HNO3, N2O, 16O18O16O, and HCN. With this addition the BMLS can test the current theory of O3 heavy ozone photochemical balance in the upper stratosphere.

  12. EOS Laser Atmosphere Wind Sounder (LAWS) investigation

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In this final report, the set of tasks that evolved from the Laser Atmosphere Wind Sounder (LAWS) Science Team are reviewed, the major accomplishments are summarized, and a complete set of resulting references provided. The tasks included preparation of a plan for the LAWS Algorithm Development and Evolution Laboratory (LADEL); participation in the preparation of a joint CNES/NASA proposal to build a space-based DWL; involvement in the Global Backscatter Experiments (GLOBE); evaluation of several DWL concepts including 'Quick-LAWS', SPNDL and several direct detection technologies; and an extensive series of system trade studies and Observing System Simulation Experiments (OSSE's). In this report, some of the key accomplishments are briefly summarized with reference to interim reports, special reports, conference/workshop presentations, and publications.

  13. RAWS: The spaceborne radar wind sounder

    NASA Technical Reports Server (NTRS)

    Moore, Richard K.

    1991-01-01

    The concept of the Radar Wind Sounder (RAWS) is discussed. The goals of the RAWS is to estimate the following three qualities: the echo power, to determine rain rate and surface wind velocity; the mean Doppler frequency, to determine the wind velocity in hydrometers; and the spread of the Doppler frequency, to determine the turbulent spread of the wind velocity. Researchers made significant progress during the first year. The feasibility of the concept seems certain. Studies indicate that a reasonably sized system can measure in the presence of ice clouds and dense water clouds. No sensitivity problems exist in rainy environments. More research is needed on the application of the radar to the measurement of rain rates and winds at the sea surface.

  14. AIRS Storm Front Approaching California (animation)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for the AIRS Storm Front Approaching California Animation

    NASA's Atmospheric Infrared Sounder instrument is able to peel back cloud cover to reveal 3-D structure of a storm's water vapor content, information that can be used to improve weather forecast models.

    In this animation the initial visible cloud image series shows a front moving toward the West Coast of the United States as a low pressure area moves into the Pacific Northwest. The 'Pineapple Express,' a stream of moisture that originates in the tropics South of Hawaii and usually crosses Mexico to enter New Mexico and Texas, has shifted Westward and is also visible moving into Baja California. The area preceding the front appears to be relatively clear in the visible images.

    As the view shifts from the visible to the infrared wavelengths which highlight water vapor, we see both cloud areas contain heavy burdens of moisture. The area which appears clear in the visible images is seen to contain water vapor near the coastline as well. The viewpoint then rotates so that we can see the vertical cross section of the fronts. The variability of the vertical extent of water vapor and the amount is now clearly visible. The storm moving in from the Gulf of Alaska is more heavily laden with water vapor than that moving in from the Southwest. The moisture is concentrated in the lower atmosphere. The colors indicate the amount of water vapor present. Blue areas denote low water vapor content; green areas are medium water vapor content; red areas signify high water vapor content. The vertical grid for the final frame ranges from 250 millibar pressure at the top to 1000 millibar pressure at the bottom. The top is about 10 km (6.2 miles) above the surface of the Earth.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in

  15. Ground-based infrared solar spectroscopic measurements of carbon monoxide during 1994 Measurement of Air Pollution From Space flights

    NASA Astrophysics Data System (ADS)

    Pougatchev, N. S.; Sen, B.; Steele, L. P.; Toon, G. C.; Yurganov, L. N.; Zander, R.; Zhao, Y.

    1998-08-01

    Results of the comparison of carbon monoxide ground-based infrared solar spectroscopic measurements with data obtained during 1994 Measurement of Air Pollution From Space (MAPS) flights are presented. Spectroscopic measurements were performed correlatively with April and October MAPS flights by nine research groups from Belgium, Canada, Germany, Japan, New Zealand, Russia, and the United States. Characterization of the techniques and error analysis were performed. The role of the CO a priori profile used in the retrieval was estimated. In most cases an agreement between spectroscopic and MAPS data is within estimated MAPS accuracy of +/-10%.

  16. Investigating In-cloud Relative Humidity and Thin Cirrus in the Upper Tropical Atmosphere Using AIRS, CALIPSO, and MLS

    NASA Astrophysics Data System (ADS)

    Liang, C. K.; Kahn, B. H.; Eldering, A.; Fetzer, E. J.

    2007-12-01

    We investigate vertical and horizontal distributions of tropical oceanic thin cirrus optical and microphysical properties observed by the Atmospheric Infrared Sounder (AIRS). These properties are related to thermodynamic quantities, i.e., relative humidity with respect to ice (RHi), and cloud top temperature derived from the AIRS Level 2 operational soundings. Differences between all sky and in-cloud RHi are explored and possible mechanisms that explain these anomalies are discussed. Furthermore, we evaluate the hypothesis that many of the observed clouds are physically much thinner than the nominal resolution of AIRS, which may lead to dry biases of in-cloud RHi. To test this we exploit the co-located AIRS RHi and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) cloud thickness. Finally, we diagnose the ability of AIRS to measure water vapor in the Tropical Tropopause Layer (TTL) using co- located observations from the Microwave Limb Sounder (MLS). From this, a combined AIRS-MLS RHi product is used to investigate joint distributions of cirrus microphysical and optical properties, and RHi in the TTL.

  17. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  18. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L.; Kroutil, R.T.

    1992-07-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  19. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L. ); Kroutil, R.T. )

    1992-01-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  20. Performance assessment of future thermal infrared geostationary instruments to monitor air quality

    NASA Astrophysics Data System (ADS)

    Sellitto, P.; Dauphin, P.; Dufour, G.; Eremenko, M.; Cuesta, J.; Coman, A.; Forêt, G.; Beekmann, M.; Gaubert, B.; Flaud, J.-M.

    2012-04-01

    Air quality (AQ) has a recognized onerous impact on human health and the environment, and then on society. It is more and more clear that constantly and efficiently monitoring AQ from space is a valuable step forward towards a more thorough comprehension of pollution processes that can have a relevant impact on the biosphere. In recent years, important progresses in this field have been made, e.g., reliable observations of several pollutants have been obtained, proving the feasibility of monitoring atmospheric composition from space. In this sense, low Earth orbit (LEO) thermal infrared (TIR) space-borne instruments are widely regarded as a useful tool to observe targeted AQ parameters like tropospheric ozone concentrations [1]. However, limitations remain with the current observation systems in particular to observe ozone in the lowermost troposphere (LmT) with a spatial and temporal resolution relevant for monitoring pollution processes at the regional scale. Indeed, LEO instruments are not well adapted to monitor small scale and short term phenomena, owing to their unsatisfactory revisit time. From this point of view, a more satisfactory concept might be based on geostationary (GEO) platforms. Current and planned GEO missions are mainly tailored on meteorological parameters retrieval and do not have sufficient spectral resolutions and signal to noise ratios (SNR) to infer information on trace gases in the LmT. New satellite missions are currently proposed that can partly overcome these limitations. Here we present a group of simulation exercises and sensitivity analyses to set-up future TIR GEO missions adapted to monitor and forecast AQ over Europe, and to evaluate their technical requirements. At this aim, we have developed a general simulator to produce pseudo-observations for different platform/instrument configurations. The core of this simulator is the KOPRA radiative transfer model, including the KOPRAfit inversion module [2]. Note that to assess the

  1. Profiling Wind and Greenhouse Gases by Infrared-laser Occultation: Algorithm and Results from Simulations in Windy Air

    NASA Astrophysics Data System (ADS)

    Plach, Andreas; Proschek, Veronika; Kirchengast, Gottfried

    2014-05-01

    We employ the Low Earth Orbit (LEO-LEO) microwave and infrared-laser occultation (LMIO) method to derive a full set of thermodynamic state variables from microwave signals and climate benchmark profiling of greenhouse gases (GHGs) and line-of-sight (l.o.s.) wind using infrared-laser signals. The focus lies on the upper troposphere/lower stratosphere region (UTLS - 5 km to 35 km). The GHG retrieval errors are generally smaller than 1% to 3% r.m.s., at a vertical resolution of about 1 km. In this study we focus on the infrared-laser part of LMIO, where we introduce a new, advanced wind retrieval algorithm to derive accurate l.o.s. wind profiles. The wind retrieval uses the reasonable assumption of the wind blowing along spherical shells (horizontal winds) and therefore the l.o.s. wind speed can be retrieved by using an Abel integral transform. A 'delta-differential transmission' principle is applied to two thoroughly selected infrared-laser signals placed at the wings of the highly symmetric C18OO absorption line (nominally ±0.004 cm-1 from the line center near 4767 cm-1) plus a related 'off-line' reference signal. The delta-differential transmission obtained by differencing these signals is clear from atmospheric broadband effects and is proportional to the wind-induced Doppler shift; it serves as the integrand of the Abel transform. The Doppler frequency shift calculated along with the wind retrieval is in turn also used in the GHG retrieval to correct the frequency of GHG-sensitive infrared-laser signals for the wind-induced Doppler shift, which enables improved GHG estimation. This step therefore provides the capability to correct potential wind-induced residual errors of the GHG retrieval in case of strong winds. We performed end-to-end simulations to test the performance of the new retrieval in windy air. The simulations used realistic atmospheric conditions (thermodynamic state variables and wind profiles) from an analysis field of the European Centre for

  2. Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs)

    NASA Astrophysics Data System (ADS)

    Hatfield, M. C.; Webley, P.; Saiet, E., II

    2014-12-01

    Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs) Numerous scientific and logistical applications exist in Alaska and other arctic regions requiring analysis of expansive, remote areas in the near infrared (NIR) and thermal infrared (TIR) bands. These include characterization of wild land fire plumes and volcanic ejecta, detailed mapping of lava flows, and inspection of lengthy segments of critical infrastructure, such as the Alaska pipeline and railroad system. Obtaining timely, repeatable, calibrated measurements of these extensive features and infrastructure networks requires localized, taskable assets such as UAVs. The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) provides practical solutions to these problem sets by pairing various IR sensors with a combination of fixed-wing and multi-rotor air vehicles. Fixed-wing assets, such as the Insitu ScanEagle, offer long reach and extended duration capabilities to quickly access remote locations and provide enduring surveillance of the target of interest. Rotary-wing assets, such as the Aeryon Scout or the ACUASI-built Ptarmigan hexcopter, provide a precision capability for detailed horizontal mapping or vertical stratification of atmospheric phenomena. When included with other ground capabilities, we will show how they can assist in decision support and hazard assessment as well as giving those in emergency management a new ability to increase knowledge of the event at hand while reducing the risk to all involved. Here, in this presentation, we illustrate how UAV's can provide the ideal tool to map and analyze the hazardous events and critical infrastructure under extreme environmental conditions.

  3. Work of PZT ceramics sounder for sound source artificial larynx

    NASA Astrophysics Data System (ADS)

    Sugio, Yuuichi; Kanetake, Ryota; Tanaka, Akimitsu; Ooe, Katsutoshi

    2007-04-01

    We aim to develop the easy-to-use artificial larynx with high tone quality. We focus on using a PZT ceramics sounder as its sound source, because it is small size, low power consumption, and harmless to humans. But conventional PZT ceramics sounder have the problem that it cannot generate an enough sound in the low frequency range, thus they cannot be used for artificial larynx. Then, we aim to develop the PZT ceramics sounder which can generate enough volume in the low frequency range. If we can lower the resonance frequency of the sounder, it can generate low pitch sound easily. Therefore I created the new diaphragm with low resonance frequency. In addition, we could obtain the high amplitude by changing method of driving. This time, we report on the characteristic comparison of this new PZT ceramics sounder and conventional one. Furthermore, for this new one, we analyzed the best alignment of PZT ceramics and the shape of the diaphragm to obtain low resonance frequency and big amplitude. In fact we analyzed the optimization of the structure. The analysis is done by computer simulation of ANSYS and Laser Doppler Vibrometer. In the future, we will add intonation to the generated sound by input wave form which is developed concurrently, and implant the sounder inside of the body by the method of fixing metal to biomolecule which is done too. And so high tone quality and convenient artificial larynx will be completed.

  4. The Advanced Technology Microwave Sounder (ATMS): A New Operational Sensor Series

    NASA Technical Reports Server (NTRS)

    Kim, Edward; Lyu, Cheng-H Joseph; Leslie, R. Vince; Baker, Neal; Mo, Tsan; Sun, Ninghai; Bi, Li; Anderson, Mike; Landrum, Mike; DeAmici, Giovanni; Gu, Degui; Foo, Alex; Ibrahim, Wael; Robinson, Kris; Chidester, Lynn; Shiue, James

    2012-01-01

    ATMS is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. ATMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first ATMS was launched October 28, 2011 on board the Suomi National Polar-orbiting Partnership (S-NPP) satellite. Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction (NWP) models; and ATMS, when combined with the Cross-track Infrared Sounder (CrIS), forms the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The microwave soundings help meet NWP sounding requirements under cloudy sky conditions and provide key profile information near the surface

  5. Transition of AIRS Products to the National Weather Service

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley

    2012-01-01

    Short-term Prediction Research and Transition Center (SPoRT) is a proven community leader for transitioning satellite products to operational end users and is working hard to bring data from Atmospheric Infrared Sounder (AIRS) to forecasters. SPoRT products using AIRS data are currently or will soon be evaluated at WFOs and National Centers (1) T and q profiles: HWT, Alaska WFOs, HRD/OPC, HMT (2) Ozone profiles: HPC/OPC (3) Carbon Monoxide: Southern and Western Region WFOs SPoRT is actively evaluating differences between V5 and V6 profiles for selected cases and will continue to provide feedback to the AIRS team as V6 development efforts conclude.

  6. The Advanced Technology Microwave Sounder (ATMS): First Year On-Orbit

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.

    2012-01-01

    The Advanced Technology Microwave Sounder (ATMS) is a new satellite microwave sounding sensor designed to provide operational weather agencies with atmospheric temperature and moisture profile information for global weather forecasting and climate applications. A TMS will continue the microwave sounding capabilities first provided by its predecessors, the Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU). The first flight unit was launched a year ago in October, 2011 aboard the Suomi-National Polar-Orbiting Partnership (S-NPP) satellite, part of the new Joint Polar-Orbiting Satellite System (JPSS). Microwave soundings by themselves are the highest-impact input data used by Numerical Weather Prediction models; and A TMS, when combined with the Cross-track Infrared Sounder (CrIS), forms the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The microwave soundings help meet sounding requirements under cloudy sky conditions and provide key profile information near the surface. ATMS was designed & built by Aerojet Corporation in Azusa, California, (now Northrop Grumman Electronic Systems). It has 22 channels spanning 23-183 GHz, closely following the channel set of the MSU, AMSU-AI/2, AMSU-B, Microwave Humidity Sounder (MHS), and Humidity Sounder for Brazil (HSB). It continues their cross-track scanning geometry, but for the first time, provides Nyquist sample spacing. All this is accomplished with approximately V. the volume, Y, the mass, and Y, the power of the three AMSUs. A description will be given of its performance from its first year of operation as determined by post-launch calibration activities. These activities include radiometric calibration using the on-board warm targets and cold space views, and geolocation determination. Example imagery and zooms of specific weather events will be shown. The second ATMS flight model is currently under construction and planned for launch on the "Jl" satellite of the JPSS program in

  7. Submillimeter Planetary Atmospheric Chemistry Exploration Sounder

    NASA Technical Reports Server (NTRS)

    Schlecht, Erich T.; Allen, Mark A.; Gill, John J.; Choonsup, Lee; Lin, Robert H.; Sin, Seth; Mehdi, Imran; Siegel, Peter H.; Maestrini, Alain

    2013-01-01

    Planetary Atmospheric Chemistry Exploration Sounder (SPACES), a high-sensitivity laboratory breadboard for a spectrometer targeted at orbital planetary atmospheric analysis. The frequency range is 520 to 590 GHz, with a target noise temperature sensitivity of 2,500 K for detecting water, sulfur compounds, carbon compounds, and other atmospheric constituents. SPACES is a prototype for a powerful tool for the exploration of the chemistry and dynamics of any planetary atmosphere. It is fundamentally a single-pixel receiver for spectral signals emitted by the relevant constituents, intended to be fed by a fixed or movable telescope/antenna. Its front-end sensor translates the received signal down to the 100-MHz range where it can be digitized and the data transferred to a spectrum analyzer for processing, spectrum generation, and accumulation. The individual microwave and submillimeter wave components (mixers, LO high-powered amplifiers, and multipliers) of SPACES were developed in cooperation with other programs, although with this type of instrument in mind. Compared to previous planetary and Earth science instruments, its broad bandwidth (approx. =.13%) and rapid tunability (approx. =.10 ms) are new developments only made possible recently by the advancement in submillimeter circuit design and processing at JPL.

  8. Planetary protection for Europa radar sounder antenna

    NASA Astrophysics Data System (ADS)

    Aaron, Kim M.; Moussessian, Alina; Newlin, Laura E.; Willis, Paul B.; Chen, Fei; Harcke, Leif J.; Chapin, Elaine; Jun, Insoo; Gim, Yonggyu; McEachen, Michael; Allen, Scotty; Kirchner, Donald; Blankenship, Donald

    2016-05-01

    The potential for habitability puts stringent requirements on planetary protection for a mission to Europa. A long-wavelength radar sounder with a large antenna is one of the proposed instruments for a future Europa mission. The size and construction of radar sounding antennas make the usual methods of meeting planetary protection requirements challenging. This paper discusses a viable planetary protection scheme for an antenna optimized for Europa radar sounding. The preferred methodology for this antenna is exposure to 100 kGy (10 Mrad) in water of gamma radiation using a Cobalt-60 source for both bulk and surface sterilization and exposure to vapor hydrogen peroxide for surface treatment for possible recontamination due to subsequent handling. For the boom-supported antenna design, selected tests were performed to confirm the suitability of these treatment methods. A portion of a coilable boom residual from an earlier mission was irradiated and its deployment repeatability confirmed with no degradation. Elasticity was measured of several fiberglass samples using a four-point bending test to confirm that there was no degradation due to radiation exposure. Vapor hydrogen peroxide treatment was applied to the silver-coated braid used as the antenna radiating element as it was the material most likely to be susceptible to oxidative attack under the treatment conditions. There was no discernable effect. These tests confirm that the radar sounding antenna for a Europa mission should be able tolerate the proposed sterilization methods.

  9. DUst Sounder and Temperature Imager Experiment (DUSTIE)

    NASA Astrophysics Data System (ADS)

    McHugh, M. J.; Fish, C. S.; Taylor, M. J.; Gordley, L. L.; Hervig, M. E.; Summers, M. E.; Siskind, D. E.

    2009-12-01

    The Dust Sounder and Temperature Imager Experiment (DUSTIE) is a proposed CubeSat mission to determine the global distribution of cosmic smoke in the atmosphere. The Earth is under continual bombardment by comets and meteoroids. Over the last 5 billion years they have brought water and the basics of life to our planet. Today they are vaporized during atmospheric entry and deposited as microscopic smoke particles in the upper atmosphere. These cosmic particles are known to be important in a host of atmospheric processes, including nucleation of ice particles, ion chemistry in the thermosphere and heterogeneous chemistry in the mesosphere. Despite this, our current understanding is based on scant observations and theory. The successful deployment of DUSTIE will offer a major advance in this important emerging area of research. DUSTIE will use a digital camera to image the Sun at 0.420 µm during spacecraft sunrise and sunset. This will provide measurements to characterize the smoke distribution over the altitude range of ~40 to 90 km. A high-inclination orbit will provide near-global coverage monthly. Simultaneous refraction measurements will yield atmospheric density profiles up to 75 km. Measured smoke extinctions will be used to derive smoke particle volume and surface area densities. DUSTIE will utilize a 3U form factor CubeSat and rely heavily upon commercial-off-the-shelf (COTS) components and proven technologies.

  10. Pioneer Venus Sounder Probe Solar Flux Radiometer

    NASA Technical Reports Server (NTRS)

    Tomasko, M. G.; Doose, L. R.; Palmer, J. M.; Holmes, A.; Wolfe, W. L.; Debell, A. G.; Brod, L. G.; Sholes, R. R.

    1980-01-01

    The Solar Flux Radiometer aboard the Pioneer Venus Sounder Probe operated successfully during its descent through the atmosphere of Venus. The instrument measured atmospheric radiance over the spectral range from 400 to 1800 nm as a function of altitude. Elevation and azimuthal measurements on the radiation field were made with five optical channels. Twelve filtered Si and Ge photovoltaic detectors were maintained near 30 C with a phase-change material. The detector output currents were processed with logarithmic transimpedance converters and digitized with an 11-bit A/D converter. Atmospheric sampling in both elevation and azimuth was done according to a Gaussian integration scheme. The serial output data averaged 20 bits/sec, including housekeeping (sync, spin period, sample timing and mode). The data were used to determine the deposition of solar energy in the atmosphere of Venus between 67 km and the surface along with upward and downward fluxes and radiances with an altitude resolution of several hundred meters. The results allow for more accurate modeling of the radiation balance of the atmosphere than previously possible.

  11. The revised AFGL (Air Force Geophysics Laboratory) Infrared Sky Survey Catalog

    NASA Astrophysics Data System (ADS)

    Price, S. D.; Murdock, T. L.

    1983-06-01

    Infrared survey measurements obtained from two probe-borne experiments flown in 1982 combined with extensive ground-based observations on AFGL sources are incorporated into a revised AFGL Four Color Infrared Survey catalog. Over 92 percent of the sky has been covered at 11 and 20 micron, 71 percent at 4 micron and 47 percent at high sensitivity at 27 micron. There are 2970 entries in the main catalog, most of which are multicolor observations. The catalog contents are resolved into two general groups: a disk population (slope= 0.4) with means colors m (11)-m(20)=2.0 and m(20)-m(27)=0.9 corresponding to color temperatures of 270K and 185K, respectively, and a spherical distribution (slope = 0.6) with a mean color difference of m(11)-m(20)=1.0 corresponding to Tc approx = 10 480K.

  12. Infrared remote sensing of cometary parent volatiles from the ground, air, and space

    NASA Technical Reports Server (NTRS)

    Mumma, Michael J.; Disanti, Michael A.; Hoban, Susan; Reuter, Dennis C.

    1991-01-01

    A balanced view of the present generation of infrared instruments for cometary compositional studies is presented. Ground-based instruments are compared with airborne and spaceborne capabilities. An attempt to give examples of the unique science achievable with each is made, and particular emphasis is on the unique aspects of a dedicated Cometary Composition Telescope in earth orbit for investigating the chemical and structural heterogeneity of the cometary nucleus.

  13. AIRS Map of Carbon Monoxide Draped on Globe: Time Series from 8/1/2005 to 9/30/2005

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of AIRS Map of Carbon Monoxide Draped on Globe

    Forest fires and agricultural burning create large amounts of carbon monoxide. AIRS provides daily global maps of carbon monoxide from space, allowing scientists to follow the global transport of this gas day-to-day. In this image sequence, carbon monoxide pollution from agricultural burning blooms repeatedly over the Amazonian basin. The gas is then transported across the Atlantic Ocean. Carbon monoxide pollution from fires in sub-Saharan Africa is also apparent.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric phenomena. The AIRS Infrared Sounder Experiment flies onboard NASA's Aqua spacecraft and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.

  14. Real-time monitoring of ozone in air using substrate-integrated hollow waveguide mid-infrared sensors.

    PubMed

    da Silveira Petruci, João Flávio; Fortes, Paula Regina; Kokoric, Vjekoslav; Wilk, Andreas; Raimundo, Ivo Milton; Cardoso, Arnaldo Alves; Mizaikoff, Boris

    2013-01-01

    Ozone is a strong oxidant that is globally used as disinfection agent for many purposes including indoor building air cleaning, during food preparation procedures, and for control and killing of bacteria such as E. coli and S. aureus. However, it has been shown that effective ozone concentrations for controlling e.g., microbial growth need to be higher than 5 ppm, thereby exceeding the recommended U.S. EPA threshold more than 10 times. Consequently, real-time monitoring of such ozone concentration levels is essential. Here, we describe the first online gas sensing system combining a compact Fourier transform infrared (FTIR) spectrometer with a new generation of gas cells, a so-called substrate-integrated hollow waveguide (iHWG). The sensor was calibrated using an UV lamp for the controlled generation of ozone in synthetic air. A calibration function was established in the concentration range of 0.3-5.4 mmol m⁻³ enabling a calculated limit of detection (LOD) at 0.14 mmol m⁻³ (3.5 ppm) of ozone. Given the adaptability of the developed IR sensing device toward a series of relevant air pollutants, and considering the potential for miniaturization e.g., in combination with tunable quantum cascade lasers in lieu of the FTIR spectrometer, a wide range of sensing and monitoring applications of beyond ozone analysis are anticipated. PMID:24213678

  15. Application of tunable infrared lasers for diagnosis of diseases by analysis of expired lung air

    NASA Astrophysics Data System (ADS)

    Chugunov, A. V.; Novoderezhkin, Vladimir I.; Panchenko, Vladislav Y.; Solomatin, Vladimir S.; Krasnikov, Victor V.; Razumikhina, T. B.

    1994-06-01

    The using of laser spectroscopy methods are proposed for diagnosis of diabetes through the measurements of acetone concentration in respiratory air. Detection of acetone concentration was performed with laser spectrometer operating in the 3 microns spectral range. Minimal detectable concentrations were found. Acetone components in expired lung air of diabetics (for adult as well as juvenile patients) are detectable by absorption spectra measurements in single pass 1m-length cell. Digital smoothing and other methods were used to improve signal to noise ratio.

  16. Continuous multichannel monitoring of cave air carbon dioxide using a pumped non-dispersive infrared analyser

    NASA Astrophysics Data System (ADS)

    Mattey, D.

    2012-04-01

    The concentration of CO2 in cave air is one of the main controls on the rate of degassing of dripwater and on the kinetics of calcite precipitation forming speleothem deposits. Measurements of cave air CO2reveal great complexity in the spatial distribution among interconnected cave chambers and temporal changes on synoptic to seasonal time scales. The rock of Gibraltar hosts a large number of caves distributed over a 300 meter range in altitude and monthly sampling and analysis of air and water combined with continuous logging of temperature, humidity and drip discharge rates since 2004 reveals the importance of density-driven seasonal ventilation which drives large-scale advection of CO2-rich air though the cave systems. Since 2008 we have deployed automatic CO2 monitoring systems that regularly sample cave air from up to 8 locations distributed laterally and vertically in St Michaels Cave located near the top of the rock at 275m asl and Ragged Staff Cave located in the heart of the rock near sea level. The logging system is controlled by a Campbell Scientific CR1000 programmable datalogger which controls an 8 port manifold connected to sampling lines leading to different parts of the cave over a distance of up to 250 meters. The manifold is pumped at a rate of 5l per minute drawing air through 6mm or 8mm id polythene tubing via a 1m Nafion loop to reduce humidity to local ambient conditions. The outlet of the primary pump leads to an open split which is sampled by a second low flow pump which delivers air at 100ml/minute to a Licor 820 CO2 analyser. The software selects the port to be sampled, flushes the line for 2 minutes and CO2 analysed as a set of 5 measurements averaged over 10 second intervals. The system then switches to the next port and when complete shuts down to conserve power after using 20 watts over a 30 minute period of analysis. In the absence of local mains power (eg from the show cave lighting system) two 12v car batteries will power the system

  17. Vertical profiling of the Martian atmosphere with the Mars Climate Sounder

    NASA Astrophysics Data System (ADS)

    McCleese, Daniel

    The Mars Climate Sounder (MCS) onboard the Mars Reconnaissance Orbiter (MRO) began observing the Martian atmosphere and surface on October 11, 2006. This paper describes investigations we are pursuing that build upon the nearly decade-long climatology of the planet acquired by TES and MOC on MGS and THEMIS on Odyssey. The MCS instrument is unique in that it is designed to acquire high vertical resolution (one-half scale height) profiles of temperature, dust, condensates and water vapor. MCS measurements are made in nine spectral intervals in the visible and infrared between 0.3 and 50 µm. The observing geometry places nine 21-element linear detector-arrays on the limb extending from just below the surface to above 80 km altitude at the tangent point. MCS observations by began on Ls=110° , southern winter, and much of our early work has focused on the South Polar Region. This location at this season is particularly attractive as a starting point for interpreting MCS data because the small amount of dust in the atmosphere makes for successful retrievals of geophysical quantities from limb radiances. MCS observations reveal new details of the intense warming of the winter middle atmosphere over CO2 ice cap. The polar warming is understood, from published numerical modeling experiments, to be a consequence of the descending branch of the Hadley cell; the intensity of which is sensitive to the amount and distribution of dust in the atmosphere at low latitudes. However, the observed intensity of the warming is underestimated in models and the location of the descending branch is poleward of that predicted. Another observed feature of the region is circumpolar very clear middle and upper atmosphere surrounding a vertically extended cloud which MCS data suggests is composed of water ice. The appearance of water ice in the cold dry air associated with the CO2 ice cap has yet to be explained. This paper describes these and other atmospheric phenomena, as well as aspects of

  18. AIRS Data Service at NASA Goddard Earth Sciences Data and Information Services (GES DISC) and Its Application to Climate Change Study

    NASA Technical Reports Server (NTRS)

    Won, Young-In; Vollimer, Bruce; Theobald, Mike; Hua, Xin-Min

    2008-01-01

    The Atmospheric Infrared Sounder (AIRS) instrument suite is designed to observe and characterize the entire atmospheric column from the surface to the top of the atmosphere in terms of surface emissivity and temperature, atmospheric temperature and humidity profiles, cloud amount and height, and the spectral outgoing infrared radiation on a global scale. The AIRS Data Support Team at the GES DISC provides data support to assist others in understanding, retrieving and extracting information from the AIRS/AMSU/HSB data products. Because a number of years has passed since its operation started, the amount of data has reached a certain level of maturity where we can address the climate change study utilizing AIRS data, In this presentation we will list various service we provide and to demonstrate how to utilize/apply the existing service to long-term and short-term variability study.

  19. FEASIBILITY STUDY TO DEMONSTRATE APPLICABILITY OF TUNABLE INFRARED LASER EMISSION SPECTROSCOPY TECHNOLOGY TO MEASURE AIR POLLUTION

    EPA Science Inventory

    This project involves the real-time measurement of air quality using open-path IR spectroscopy. A prototype open-path tunable laser absorption spectroscopy instrument was designed, built, and successfully operated for several hundred hours between October and December 2000. The...

  20. The Exomars Climate Sounder (EMCS) Investigation

    NASA Astrophysics Data System (ADS)

    Forget, F.; Schofield, J. T.; Kass, D. M.; Kleinböhl, A.; McCleese, D. J.; Allen, M. A.; Foote, M. C.; Millour, E.; Spiga, A.; Talagrand, O.; Calcutt, S. B.; Irwin, P. G. J.; Read, P. L.; Lewis, S. R.; Fouchet, T.; Lefèvre, F.; Määttänen, A.; Barnes, J. R.; Bougher, S. W.; Haberle, R. M.; Jeganathan, M.; Bowles, N.

    2011-10-01

    The ExoMars Climate Sounder (EMCS) investigation is developed at the Jet Propulsion Laboratory (Principal Investigator J. T. Schofield) in collaboration with an international scientific team from France, the United Kingdom and the USA. EMCS plans to map daily, global, pole-to-pole profiles of temperature, dust, water and CO2 ices, and water vapor from the proposed 2016 ExoMars Trace Gas Orbiter (EMTGO). These profiles are to be assimilated into Mars General Circulation Models (MGCMs) to generate global, interpolated fields of measured and derived parameters such as wind. Sciences objectives of EMCS are to: Enhance understanding of Mars photochemistry by providing daily, global, high vertical resolution fields of atmospheric state, aerosol distribution, and water vapor concentration. EMCS atmospheric state measurements, combined with data assimilation, characterize the transport, sources and sinks of trace gases measured by the proposed EMTGO. The aerosol measurements reveal the heterogeneous photochemical pathways of trace gases. EMCS plans to map water vapor, the key source gas for odd hydrogen, known to be important in Martian photochemistry. Extend the MRO/MCS climatology of high vertical resolution measurements of the lower and middle atmosphere of Mars, with the improved coverage of local time provided by the proposed EMTGO. EMCS will determine the diurnal, seasonal & long-term variability of temperature and aerosol, and its impact on photochemistry. EMCS climatology, combined with earlier data, would relate EMTGO observations to earlier trace gas measurements. Support future Mars missions with measured climatology and near real-time density profile retrievals for landing and aerocapture, in the same way that MRO/MCS supported the Phoenix landing and is supporting the Mars Science Laboratory (MSL) landing. EMCS could be the only instrument in orbit able to support Entry, Descent and Landing (EDL) for the proposed ExoMars 2018 Rover Mission.

  1. Open-air, broad-bandwidth trace gas sensing with a mid-infrared optical frequency comb

    NASA Astrophysics Data System (ADS)

    Nugent-Glandorf, Lora; Giorgetta, Fabrizio R.; Diddams, Scott A.

    2015-05-01

    A mid-infrared frequency comb is produced via an optical parametric oscillator pumped by an amplified 100 MHz Yb:fiber mode-locked laser. We use this source to make measurements of the concentration of the atmospherically relevant species of CH4 and H2O over a bandwidth of 100 nm centered at 3.25 μm. Multiple absorption lines for each species are detected with millisecond acquisition time using a virtual-image phased array spectrometer. The measured wavelength-dependent absorption profile is compared to and fitted by a model, yielding quantitative values of the atmospheric concentration of both CH4 and H2O in a controlled indoor environment, as well as over a 26-m open-air outdoor path.

  2. AIRS Data Distribution at NASA GES DISC DAAC

    NASA Astrophysics Data System (ADS)

    Qin, J. C.; Cho, S.; Li, J. Y.; Phelps, C.

    2003-04-01

    The Atmospheric Infrared Sounder (AIRS) data product suite is now available at the Distributed Active Archive Center (DAAC) located at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) in Greenbelt, Maryland, USA. The Atmospheric Dynamics Data Support Team (atmdyn-dst@daac.gsfc.nasa.gov) is providing user services to help with understanding, accessing and utilizing AIRS data. These services include assistance with product ordering and distribution, access to online technical documentation and HDF-EOS format information, development of online data analysis tools, data mining, and educational resources. The AIRS data is available via the DAAC Search and Order interface (http://daac.gsfc.nasa.gov/data/), the EOS Data Gateway (http://eos.nasa.gov/imswelcome/) or the EOS Core System Datapool (ftp://g0dps01u.ecs.nasa.gov/). The AIRS data support website is located at http://daac.gsfc.nasa.gov/atmodyn/airs/. AIRS data products are a combination of AIRS, Advanced Microwave Sounding Unit (AMSU-A) and Humidity Sounder for Brazil (HSB) measurements. Global coverage by the instruments is obtained twice daily (day and night) and the data along the orbit is processed into 6-minute granules. AIRS alone has 2,378 channels measuring in the infrared range 3.74-15.4 mm and four channels measuring in the visible/near-infrared range 0.4-1.1mm. A web-based AIRS data subsetter is among the tools available to perform channel subsetting for geolocated calibrated radiances (Level 1B) as well as variable subsetting for atmospheric final retrievals (Level 2). Also useful is AIRS QuickLook, a data visualization application which allows users to view AIRS Level 1B data online for a specific channel prior to ordering or downloading data. Global map is also provided along with image to show geographic coverage of the granule and flight direction of the Aqua spacecraft. AIRS Level 1B data was released in March 2003 and Level 2 products are available May 2003.

  3. The added value of a visible channel to a geostationary thermal infrared instrument to monitor ozone for air quality

    NASA Astrophysics Data System (ADS)

    Hache, E.; Attié, J.-L.; Tourneur, C.; Ricaud, P.; Coret, L.; Lahoz, W. A.; El Amraoui, L.; Josse, B.; Hamer, P.; Warner, J.; Liu, X.; Chance, K.; Höpfner, M.; Spurr, R.; Natraj, V.; Kulawik, S.; Eldering, A.; Orphal, J.

    2014-02-01

    Ozone is a tropospheric pollutant and plays a key role in determining the air quality that affects human wellbeing. In this study, we compare the capability of two hypothetical grating spectrometers onboard a geostationary (GEO) satellite to sense ozone in the lowermost troposphere (surface and the 0-1 km column). We consider one week during the Northern Hemisphere summer simulated by a chemical transport model, and use the two GEO instrument configurations to measure ozone concentration (1) in the thermal infrared (GEO TIR) and (2) in the thermal infrared and the visible (GEO TIR+VIS). These configurations are compared against each other, and also against an ozone reference state and a priori ozone information. In a first approximation, we assume clear sky conditions neglecting the influence of aerosols and clouds. A number of statistical tests are used to assess the performance of the two GEO configurations. We consider land and sea pixels and whether differences between the two in the performance are significant. Results show that the GEO TIR+VIS configuration provides a better representation of the ozone field both for surface ozone and the 0-1 km ozone column during the daytime especially over land.

  4. The added value of a visible channel to a geostationary thermal infrared instrument to monitor ozone for air quality

    NASA Astrophysics Data System (ADS)

    Hache, E.; Attié, J.-L.; Tourneur, C.; Ricaud, P.; Coret, L.; Lahoz, W. A.; El Amraoui, L.; Josse, B.; Hamer, P.; Warner, J.; Liu, X.; Chance, K.; Höpfner, M.; Spurr, R.; Natraj, V.; Kulawik, S.; Eldering, A.; Orphal, J.

    2014-07-01

    Ozone is a tropospheric pollutant and plays a key role in determining the air quality that affects human wellbeing. In this study, we compare the capability of two hypothetical grating spectrometers onboard a geostationary (GEO) satellite to sense ozone in the lowermost troposphere (surface and the 0-1 km column). We consider 1 week during the Northern Hemisphere summer simulated by a chemical transport model, and use the two GEO instrument configurations to measure ozone concentration (1) in the thermal infrared (GEO TIR) and (2) in the thermal infrared and the visible (GEO TIR+VIS). These configurations are compared against each other, and also against an ozone reference state and a priori ozone information. In a first approximation, we assume clear sky conditions neglecting the influence of aerosols and clouds. A number of statistical tests are used to assess the performance of the two GEO configurations. We consider land and sea pixels and whether differences between the two in the performance are significant. Results show that the GEO TIR+VIS configuration provides a better representation of the ozone field both for surface ozone and the 0-1 km ozone column during the daytime especially over land.

  5. Latest developments of geostationary microwave sounder technologies for NOAA's mission

    NASA Astrophysics Data System (ADS)

    Bajpai, Shyam; Madden, Michael; Chu, Donald; Yapur, Martin

    2006-12-01

    The National Oceanic and Atmospheric Administration (NOAA) have been flying microwave sounders since 1975 on Polar Operational Environmental Satellites (POES). Microwave observations have made significant contributions to the understanding of the atmosphere and earth surface. This has helped in improving weather and storm tracking forecasts. However, NOAA's Geostationary Operational Environmental Satellites (GOES) have microwave requirements that can not be met due to the unavailability of proven technologies. Several studies of a Geostationary Microwave Sounder (GMS) have been conducted. Among those, are the Geostationary Microwave Sounder (GEM) that uses a mechanically steered solid dish antenna and the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) that utilizes a sparse aperture array. Both designs take advantage of the latest developments in sensor technology. NASA/Jet Propulsion Lab (JPL) has recently successfully built and tested a prototype ground-based GeoSTAR at 50 GHz frequency with promising test results. Current GOES IR Sounders are limited to cloud top observations. Therefore, a sounding suite of IR and Microwave should be able to provide observations under clear as well as cloudy conditions all the time. This paper presents the results of the Geostationary Microwave Sounder studies, user requirements, frequencies, technologies, limitations, and implementation strategies.

  6. The Precision and Accuracy of AIRS Level 1B Radiances for Climate Studies

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas J.; Gaiser, Steve; Pagano, Tom; Aumann, Hartmut

    2004-01-01

    We investigate uncertainties in the Atmospheric Infrared Sounder (AIRS) radiances based on in-flight and preflight calibration algorithms and observations. The global coverage and spectra1 resolution ((lamda)/(Delta)(lamda) 1200) of AIRS enable it to produce a data set that can be used as a climate data record over the lifetime of the instrument. Therefore, we examine the effects of the uncertainties in the calibration and the detector stability on future climate studies. The uncertainties of the parameters that go into the AIRS radiometric calibration are propagated to estimate the accuracy of the radiances and any climate data record created from AIRS measurements. The calculated radiance uncertainties are consistent with observations. Algorithm enhancements may be able to reduce the radiance uncertainties by as much as 7%. We find that the orbital variation of the gain contributes a brightness temperature bias of < 0.01 K.

  7. Validating AIRS upper atmosphere water vapor retrievals using aircraft and balloon in situ measurements

    NASA Astrophysics Data System (ADS)

    Hagan, D. E.; Webster, C. R.; Farmer, C. B.; May, R. D.; Herman, R. L.; Weinstock, E. M.; Christensen, L. E.; Lait, L. R.; Newman, P. A.

    2004-11-01

    This paper provides an initial assessment of the accuracy of the Atmospheric Infrared Sounder (AIRS) water vapor retrievals from 500 to 100 mbar. AIRS satellite measurements are compared with accurate aircraft (NASA WB57) and balloon in situ water vapor measurements obtained during the NASA Pre-Aura Validation Experiment (Pre-AVE) in Costa Rica during Jan. 2004. AIRS retrieval (each pressure level of a single footprint) of water vapor amount agrees with the in situ measurements to ~25% or better if matched closely in time (1 hr) and space (50-100 km). Both AIRS and in situ measurements observe similar significant variation in moisture amount over a two-day period, associated with large-scale changes in weather patterns.

  8. Atmospheric profile retrieval with AIRS data and validation at the ARM CART site

    NASA Astrophysics Data System (ADS)

    Wu, Xuebao; Li, Jun; Zhang, Wenjian; Wang, Fang

    2005-09-01

    The physical retrieval algorithm of atmospheric temperature and moisture distribution from the Atmospheric InfraRed Sounder (AIRS) radiances is presented. The retrieval algorithm is applied to AIRS clearsky radiance measurements. The algorithm employs a statistical retrieval followed by a subsequent nonlinear physical retrieval. The regression coefficients for the statistical retrieval are derived from a dataset of global radiosonde observations (RAOBs) comprising atmospheric temperature, moisture, and ozone profiles. Evaluation of the retrieved profiles is performed by a comparison with RAOBs from the Atmospheric Radiation Measurement (ARM) Program Cloud And Radiation Testbed (CART) in Oklahoma, U. S. A. Comparisons show that the physicallybased AIRS retrievals agree with the RAOBs from the ARM CART site with a Root Mean Square Error (RMSE) of 1 K on average for temperature profiles above 850 hPa, and approximately 10% on average for relative humidity profiles. With its improved spectral resolution, AIRS depicts more detailed structure than the current Geostationary Operational Environmental Satellite (GOES) sounder when comparing AIRS sounding retrievals with the operational GOES sounding products.

  9. Gravity Wave Variances and Propagation Derived from AIRS Radiances

    NASA Technical Reports Server (NTRS)

    Gong, Jie; Wu, Dong L.; Eckermann, S. D.

    2012-01-01

    As the first gravity wave (GW) climatology study using nadir-viewing infrared sounders, 50 Atmospheric Infrared Sounder (AIRS) radiance channels are selected to estimate GW variances at pressure levels between 2-100 hPa. The GW variance for each scan in the cross-track direction is derived from radiance perturbations in the scan, independently of adjacent scans along the orbit. Since the scanning swaths are perpendicular to the satellite orbits, which are inclined meridionally at most latitudes, the zonal component of GW propagation can be inferred by differencing the variances derived between the westmost and the eastmost viewing angles. Consistent with previous GW studies using various satellite instruments, monthly mean AIRS variance shows large enhancements over meridionally oriented mountain ranges as well as some islands at winter hemisphere high latitudes. Enhanced wave activities are also found above tropical deep convective regions. GWs prefer to propagate westward above mountain ranges, and eastward above deep convection. AIRS 90 field-of-views (FOVs), ranging from +48 deg. to -48 deg. off nadir, can detect large-amplitude GWs with a phase velocity propagating preferentially at steep angles (e.g., those from orographic and convective sources). The annual cycle dominates the GW variances and the preferred propagation directions for all latitudes. Indication of a weak two-year variation in the tropics is found, which is presumably related to the Quasi-biennial oscillation (QBO). AIRS geometry makes its out-tracks capable of detecting GWs with vertical wavelengths substantially shorter than the thickness of instrument weighting functions. The novel discovery of AIRS capability of observing shallow inertia GWs will expand the potential of satellite GW remote sensing and provide further constraints on the GW drag parameterization schemes in the general circulation models (GCMs).

  10. Stratospheric and mesospheric HO2 observations from the Aura Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Millán, L.; Wang, S.; Livesey, N.; Kinnison, D.; Sagawa, H.; Kasai, Y.

    2014-09-01

    This study introduces stratospheric and mesospheric hydroperoxyl radical (HO2) estimates from the Aura Microwave Limb Sounder (MLS) using an offline retrieval (i.e. run separately from the standard MLS algorithm). This new dataset provides two daily zonal averages, one during daytime and one during nighttime, with a varying vertical resolution from about 4 km at 10 hPa to around 14 km at 0.0032 hPa. A description of the methodology and an error analysis are presented. Comparisons against the Whole Atmosphere Community Climate Model (WACCM), the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Far Infrared Spectrometer (FIRS-2) measurements, as well as, photochemical simulations demonstrate the robustness of the retrieval and indicate that the retrieval is sensitive enough to detect mesospheric HO2 layers during both day and night. This new dataset is the first long-term HO2 stratospheric and mesospheric satellite record and it provides needed constraints to help resolve the O3 deficit problem and the "HOx dilemma".

  11. Stratospheric and mesospheric HO2 observations from the Aura Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Millán, L.; Wang, S.; Livesey, N.; Kinnison, D.; Sagawa, H.; Kasai, Y.

    2015-03-01

    This study introduces stratospheric and mesospheric hydroperoxyl radical (HO2) estimates from the Aura Microwave Limb Sounder (MLS) using an offline retrieval (i.e. run separately from the standard MLS algorithm). This new data set provides two daily zonal averages, one during daytime from 10 to 0.0032 hPa (using day-minus-night differences between 10 and 1 hPa to ameliorate systematic biases) and one during nighttime from 1 to 0.0032 hPa. The vertical resolution of this new data set varies from about 4 km at 10 hPa to around 14 km at 0.0032 hPa. A description of the methodology and an error analysis are presented. Comparisons against the Whole Atmosphere Community Climate Model (WACCM), the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) and the Far Infrared Spectrometer (FIRS-2) measurements, as well as photochemical simulations, demonstrate the robustness of the retrieval and indicate that the retrieval is sensitive enough to detect mesospheric HO2 layers during both day and night. This new data set is the first long-term HO2 stratospheric and mesospheric satellite record and it provides needed constraints to help resolve the O3 deficit problem and the "HOx dilemma".

  12. View to the eastnortheast of the Sounder Antenna OvertheHorizon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the east-northeast of the Sounder Antenna - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Five Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  13. View to the northeast of the Sounder Antenna OvertheHorizon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View to the northeast of the Sounder Antenna - Over-the-Horizon Backscatter Radar Network, Christmas Valley Radar Site Transmit Sector Five Sounder Antennas, On unnamed road west of Lost Forest Road, Christmas Valley, Lake County, OR

  14. Accuracy of Geophysical Parameters Derived from AIRS/AMSU as a Function of Fractional Cloud Cover

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Barnet, Chris; Blaisdell, John; Iredell, Lena; Keita, Fricky; Kouvaris, Lou; Molnar, Gyula; Chahine, Moustafa

    2006-01-01

    AIRS was launched on EOS Aqua on May 4,2002, together with AMSU A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The sounding goals of AIRS are to produce 1 km tropospheric layer mean temperatures with an rms error of lK, and layer precipitable water with an rms error of 20 percent, in cases with up to 80 percent effective cloud cover. The basic theory used to analyze Atmospheric InfraRed Sounder/Advanced Microwave Sounding Unit/Humidity Sounder Brazil (AIRS/AMSU/HSB) data in the presence of clouds, called the at-launch algorithm, was described previously. Pre-launch simulation studies using this algorithm indicated that these results should be achievable. Some modifications have been made to the at-launch retrieval algorithm as described in this paper. Sample fields of parameters retrieved from AIRS/AMSU/HSB data are presented and validated as a function of retrieved fractional cloud cover. As in simulation, the degradation of retrieval accuracy with increasing cloud cover is small and the RMS accuracy of lower tropospheric temperature retrieved with 80 percent cloud cover is about 0.5 K poorer than for clear cases. HSB failed in February 2003, and consequently HSB channel radiances are not used in the results shown in this paper. The AIRS/AMSU retrieval algorithm described in this paper, called Version 4, become operational at the Goddard DAAC (Distributed Active Archive Center) in April 2003 and is being used to analyze near-real time AIRS/AMSU data. Historical AIRS/AMSU data, going backwards from March 2005 through September 2002, is also being analyzed by the DAAC using the Version 4 algorithm.

  15. A Comparison of the Red Green Blue (RGB) Air Mass Imagery and Hyperspectral Infrared Retrieved Profiles and NOAA G-IV Dropsondes

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Folmer, Michael; Dunion, Jason

    2014-01-01

    RGB air mass imagery is derived from multiple channels or paired channel differences. The combination of channels and channel differences means the resulting imagery does not represent a quantity or physical parameter such as brightness temperature in conventional single channel imagery. Without a specific quantity to reference, forecasters are often confused as to what RGB products represent. Hyperspectral infrared retrieved profiles and NOAA G-IV dropsondes provide insight about the vertical structure of the air mass represented on the RGB air mass imagery and are a first step to validating the imagery.

  16. Lessons Learned from the AIRS Pre-Flight Radiometric Calibration

    NASA Technical Reports Server (NTRS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Weiler, Margie

    2013-01-01

    The Atmospheric Infrared Sounder (AIRS) instrument flies on the NASA Aqua satellite and measures the upwelling hyperspectral earth radiance in the spectral range of 3.7-15.4 micron with a nominal ground resolution at nadir of 13.5 km. The AIRS spectra are achieved using a temperature controlled grating spectrometer and HgCdTe infrared linear arrays providing 2378 channels with a nominal spectral resolution of approximately 1200. The AIRS pre-flight tests that impact the radiometric calibration include a full system radiometric response (linearity), polarization response, and response vs scan angle (RVS). We re-derive the AIRS instrument radiometric calibration coefficients from the pre-flight polarization measurements, the response vs scan (RVS) angle tests as well as the linearity tests, and a recent lunar roll test that allowed the AIRS to view the moon. The data and method for deriving the coefficients is discussed in detail and the resulting values compared amongst the different tests. Finally, we examine the residual errors in the reconstruction of the external calibrator blackbody radiances and the efficacy of a new radiometric uncertainty model. Results show the radiometric calibration of AIRS to be excellent and the radiometric uncertainty model does a reasonable job of characterizing the errors.

  17. Microwave Limb Sounder/El Nino Watch - February thru December, 1997

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This series of six images shows the movement of atmospheric water vapor over the Pacific Ocean during the formation of the 1997 El Nino condition. Higher than normal ocean water temperatures increase the rate of evaporation and the resulting warm moist air rises into the atmosphere altering global weather patterns. Data obtained by the Microwave Limb Sounder (MLS) on NASA's Upper Atmosphere Research Satellite (UARS), from late February 1997 to late December 1997, show the movement from the western Pacific to the eastern Pacific of high levels of water vapor (red) at 10 kilometers (6 miles) above the surface. Areas of unusually drier air (blue) appear over Indonesia. December 1997 data also show a rapid increase of water vapor off the coast of South America, the result of very high water temperatures in that region.

  18. A Comprehensive Analysis of AIRS Near Surface Air Temperature and Water Vapor Over Land and Tropical Ocean

    NASA Astrophysics Data System (ADS)

    Dang, H. V. T.; Lambrigtsen, B.; Manning, E. M.; Fetzer, E. J.; Wong, S.; Teixeira, J.

    2015-12-01

    Version 6 (V6) of the Atmospheric Infrared Sounder's (AIRS) combined infrared and microwave (IR+MW) retrieval of near surface air temperature (NSAT) and water vapor (NSWV) is validated over the United States with the densely populated MESONET data. MESONET data is a collection of surface/near surface meteorological data from many federal and state agencies. The ones used for this analysis are measured from instruments maintained by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Interagency Remote Automatic Weather Stations (RAWS), resulting in a little more than four thousand locations throughout the US. Over the Tropical oceans, NSAT and NSWV are compared to a network of moored buoys from the Tropical Atmosphere Ocean/Triangle Trans-Ocean Buoy Network (TAO/TRITON), and the Pilot Research Moored Array in the Tropical Atlantic (PIRATA). With the analysis of AIRS surface and near surface products over ocean, we glean information on how retrieval of NSAT and NSWV over land can be improved and why it needs some adjustments. We also compare AIRS initial guess of near surface products that are trained on fifty days of ECMWF along with AIRS calibrated radiances, to ECMWF analysis data. The comparison is done to show the differing characteristics of AIRS initial guesses from ECMWF.

  19. The high resoultion dynamics limb sounder (HIRDLS): An instrument for the study of global change

    NASA Technical Reports Server (NTRS)

    Gille, J. C.; Barnett, J. J.

    1992-01-01

    Two groups, in the Unites States and the United Kingdom, proposed to further develop and use infrared limb scanning instruments in atmospheric studies from Earth Observing System (EOS). Subsequent review showed that the scientific objectives and basic measurement approaches were very similar, although there were differences in the proposed instrumentation. Their teams agreed to merge the two investigations into the High Resolution Dynamics Limb Sounder (HIRDLS). Under the resulting understanding, the two teams have combined, and will produce a single design to satisfy the scientific requirements of their investigations. The characteristics of limb scanning and earlier experiments are reviewed. The HIRDLS scientific objectives and requirements on the derived geophysical quantities are presented, and the way in which they drive the design of HIRDLS is indicated. A brief description of the HIRDLS instrument and a summary of HIRDLS capabilities follow.

  20. Tropical stratospheric water vapor measured by the microwave limb sounder (MLS)

    NASA Technical Reports Server (NTRS)

    Carr, E. S.; Harwood, R. S.; Mote, P. W.; Peckham, G. E.; Suttie, R. A.; Lahoz, W. A.; O'Neill, A.; Froidevaux, L.; Jarnot, R. F.; Read, W. G.

    1995-01-01

    The lower stratospheric variability of equatorial water vapor, measured by the Microwave Limb Sounder (MLS), follows an annual cycle modulated by the quasi-biennial oscillation. At levels higher in the stratosphere, water vapor measurements exhibit a semi-annual oscillatory signal with the largest amplitudes at 2.2 and 1hPa. Zonal-mean cross sections of MLS water vapor are consistent with previous satellite measurements from the limb infrared monitor of the stratosphere (LIMS) and the stratospheric Aerosol and Gas Experiment 2 (SAGE 2) instruments in that they show water vapor increasing upwards and the polewards from a well defined minimum in the tropics. The minimum values vary in height between the retrieved 46 and 22hPa pressure levels.

  1. Quality control of AIRS total column ozone data within tropical cyclones

    NASA Astrophysics Data System (ADS)

    Liu, Yin; Zou, Xiaolei

    2016-06-01

    The Atmospheric Infrared Sounder (AIRS) provides infrared radiance observations twice daily, which can be used to retrieve total column ozone with high spatial resolution. However, it was found that almost all of the ozone data within typhoons and hurricanes were flagged to be of bad quality by the AIRS original quality control (QC) scheme. This determination was based on the ratio of total precipitable water (TPW) error divided by TPW value, where TPW was an AIRS retrieval product. It was found that the difficulty in finding total column ozone data that could pass AIRS QC was related to the low TPWemployed in the AIRS QC algorithm. In this paper, a new two-step QC scheme for AIRS total column ozone is developed. A new ratio is defined which replaces the AIRS TPW with the zonal mean TPW retrieved from the Advanced Microwave Sounding Unit. The first QC step is to remove outliers when the new ratio exceeds 33%. Linear regression models between total column ozone and mean potential vorticity are subsequently developed with daily updates, which are required for future applications of the proposed total ozone QC algorithm to vortex initialization and assimilation of AIRS data. In the second QC step, observations that significantly deviate from the models are further removed using a biweighting algorithm. Numerical results for two typhoon cases and two hurricane cases show that a large amount of good quality AIRS total ozone data is kept within Tropical Cyclones after implementing the proposed QC algorithm.

  2. Air Force electronic warfare evaluation simulator (AFEWES) infrared test and evaluation capabilities

    NASA Astrophysics Data System (ADS)

    Shepherd, Seth D.

    2002-07-01

    The Air Force Electronic Warfare Evaluation Simulator IR Countermeasures test facility currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, LASERs, flares and lamp-based jammer systems. The simulations of IR missiles in flight include real missile seeker hardware mounted in a six degree-of-freedom flight simulation table. The simulations of aircraft signatures and IR countermeasures are accomplished by using up to eight xenon arc lamps, located in 9 inch X 3 inch cylindrical housings, in the presentation foreground. A mirror system keeps the high intensity IR sources in the missile field of view. Range closure is simulated in the background by zooming in on the scene and int eh foreground by separating and controlling the irises of the arc lamp sources for property spatial and intensity characteristics. Al relative motion and range closure is controlled by missile flyout software and aircraft flight-profile software models.

  3. Film handling procedures for Apollo 17 lunar sounder

    NASA Technical Reports Server (NTRS)

    Weinstein, M. S.

    1972-01-01

    Film handling procedures for the Apollo 17 Lunar Sounder are itemized, including purchase of flight film, establishment of processing standards, transportation of flight films, flight film certification, application of pre- and post-sensitometry, film loading and downloading, film processing, titling, and duplication.

  4. Results of the international ionospheric Doppler sounder network

    NASA Astrophysics Data System (ADS)

    Lastovicka, Jan; Chum, Jaroslav

    2016-07-01

    This paper summarizes main recent results reached by the Czech-lead international network of ionospheric Doppler sounders. The network consists of Doppler sounders in the western half of Czechia (5 measuring paths, 3 frequencies with central receivers in Prague), northern Taiwan (3 transmitters, two separated receivers, 1 frequency), and three similar systems (3 measuring paths with 1 receiver and 1 frequency) in Tucuman (north-western Argentina), Hermanus (the southernmost South Africa) and Luisville (northern South Africa). Three main areas of research have been (1) statistical properties of gravity waves, (2) ionospheric effects of earthquakes, and (3) low latitude/equatorial phenomena. Some results: (1) the theoretically expected dominance of gravity wave propagation against wind has been confirmed; (2) impact of the Tohoku 2001 M9.0 earthquake was registered in the ionosphere over the Czech Republic as long-period infrasound on the distance of about 9000 km from epicenter; analysis of ionospheric infrasound excited by the Nepal 2015 M7.8 earthquake observed by the Czech and Taiwan Doppler sounders showed that the intensity of ionospheric signal is significantly height dependent and that the Doppler shift depends not only on the advection (up and down motion) of the reflecting layer but also on the compression/rarefaction of the electron gas; (3) spread F structures observed by Doppler sounders in Tucuman and Taiwan (both under the crest of equatorial ionization anomaly) provide results consistent with S4 scintillation data and with previous optical, GPS and satellite measurements.

  5. EVALUATION OF A PORTABLE FOURIER TRANSFORM INFRARED GAS ANALYZER FOR MEASUREMENTS OF AIR TOXICS IN POLLUTION PREVENTION RESEARCH

    EPA Science Inventory

    A portable Fourier transform infrared gas analyzer with a photoacoustic detector performed reliably during pollution prevention research at two industrial facilities. It exhibited good agreement (within approximately 6%) with other analytical instruments (dispersive infrared and ...

  6. Estimation of planetary surface roughness by HF sounder observation

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ono, T.

    Japanese Martian exploration project "Nozomi" was to carry out several science missions. Plasma Wave Sounder, one of those onboard missions, was an HF sounder to study Martian plasma environment, and Martian surface with the altimetry mode (Oya and Ono, 1998) as well. The altimetry mode observation was studied by means of computer simulations utilizing the KiSS code which had been originally designed to simulate the SELENE Lunar Radar Sounder, a spaceborne HF GPR, based on Kirchhoff approximation theory (Kobayashi, Oya and Ono, 2002). We found an empirical power law for the standard deviation of observed altitudes over Gaussian random rough surfaces: it varies in proportion to the square of the RMS gradient of the surface √{2} hRMS{λ_0, where hRMS and λ_0 are the RMS height of the surface and the correlation distance of the surface, respectively. We applied Geometrical optics to understand this empirical power law, and derived a square power law for the standard deviation of the observed altitude. Our Geometrical optics model assumed the followings: 1) the observed surface is a Gaussian random rough surface, 2) the mean surface is a flat horizontal plane, 3) the observed surface echo is the back scattering echoes, 4) the observed altitude is the mean value of the apparent range of those back scattering echoes. These results imply that HF sounder may be utilized to measure the surface roughness of planetary bodies in terms of the RMS gradient of the surface. Refrence: H. Oya and T. Ono, A new altimeter for Mars land shape observations utilizing the ionospheric sounder system onboard the Planet-B spacecraft, Earth Planets Space, Vol. 50, pp.229-234, 1998 T. Kobayashi, H. Oya, and T. Ono, A-scope analysis of subsurface radar sounding of lunar mare region, Earth Planets Space, Vol. 54, pp.973-982, 2002

  7. Rotational infrared polarization modulator using a MEMS-based air turbine with different types of journal bearing

    NASA Astrophysics Data System (ADS)

    Hara, Motoaki; Tanaka, Shuji; Esashi, Masayoshi

    2003-03-01

    This paper describes rotational infrared polarization modulators using a micro-electromechanical-system-based (MEMS-based) air turbine with different types of journal bearing. Three types of journal bearing, circular, symmetrical two-lobed and asymmetrical seven-lobed journal bearing, were compared. Using an optical displacement meter and a high speed camera, it was confirmed that all turbines exhibit three modes of rotation: (a) low speed mode, (b) intermediate mode and (c) high speed mode in this order, when decreasing N2 flow rate to an aerostatic thrust bearing. In the low speed mode, the rotor is lifted up by excess flow to the thrust bearing, making a contact with an upper layer. In the high speed mode, the rotor is levitated without any contact to the upper and lower layers by balanced flow to the thrust bearing, and the maximum rotational speed of 74000 rpm was achieved using the asymmetrical seven-lobed bearing. The rotation in this mode is, however, discontinuous due to the collision between the rotor and the journal bearing. It was concluded that a journal bearing with sufficient load capacity is necessary for continuous high speed rotation.

  8. Operating distance calculation of ground-based and air-based infrared system based on Lowtran7

    NASA Astrophysics Data System (ADS)

    Ren, Kan; Tian, Jie; Gu, Guohua; Chen, Qian

    2016-07-01

    In this paper, the infrared system operating distance model of point target based on the contrast is used, starting from the target radiance and atmospheric transmission parameters in the operating distance formula. The radiance of different point targets detected by ground-based and air-based detector are analyzed, and the spectral division method is used for the integration of target and background radiance, the databases of atmospheric spectral radiance and transmittance are established by calling Lowtran7. A new method for solving the operating distance formula is proposed. And the operating distance calculation system is established, which improves the efficiency and accuracy of calculation. The databases of atmospheric spectral radiance and transmittance of five meteorological conditions are generated, and the variations of them with wavelength and range are given. The atmospheric radiance of infinite transmission range can be considered as the atmospheric radiance of 100 km by calculating the integration of wavelength. The targets and detectors parameters are set to be simulated by using the generated database. The operating distance of each zenith angle is calculated, and spatial distribution of operating distance is given in the meteorological condition of mid latitude summer.

  9. Countermeasure effectiveness against a man-portable air-defense system containing a two-color spinscan infrared seeker

    NASA Astrophysics Data System (ADS)

    Jackman, James; Richardson, Mark; Butters, Brian; Walmsley, Roy

    2011-12-01

    Man-portable air-defense (MANPAD) systems have developed sophisticated counter-countermeasures (CCM) to try and defeat any expendable countermeasure that is deployed by an aircraft. One of these is a seeker that is able to detect in two different parts of the electromagnetic spectrum. Termed two-color, the seeker can compare the emissions from the target and a countermeasure in different wavebands and reject the countermeasure. In this paper we describe the modeling process of a two-color infrared seeker using COUNTERSIM, a missile engagement and countermeasure software simulation tool. First, the simulations model a MANPAD with a two-color CCM which is fired against a fast jet model and a transport aircraft model releasing reactive countermeasures. This is then compared to when the aircraft releases countermeasures throughout an engagement up to the hit point to investigate the optimum flare firing time. The results show that the release time of expendable decoys as a countermeasure against a MANPAD with a two-color CCM is critical.

  10. Comparison of Upper Tropospheric Water Vapor from AIRS and Cryogenic Frostpoint Hygrometers

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Vomel, Holger

    2004-01-01

    Upper tropospheric water vapor (UTWV) from the Atmospheric Infrared Sounder (AIRS) experiment on NASA's Aqua spacecraft has the potential of addressing several important climate questions. The specified AIRS system measurement uncertainty for water vapor is 20 percent absolute averaged over 2 km layers. Cryogenic frostpoint hygrometers (CFH) are balloon-borne water vapor sensors responsive from the surface into the lower stratosphere. Several dozen coincident, collocated CFH profiles have been obtained for AlRS validation. The combination of CFH sensitivity and sample size offers a statistically compelling picture of AIRS UTWV measurement capability. We present a comparison between CFH observations and AlRS retrievals. We focus on the altitude range from the middle troposphere up to heights at the limits of AlRS sensitivity to water vapor, believed to be around 100-1 50 hPa.

  11. Evaluating the Impact of AIRS Observations on Regional Forecasts at the SPoRT Center

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley

    2011-01-01

    NASA Short-term Prediction Research and Transition (SPoRT) Center collaborates with operational partners of different sizes and operational goals to improve forecasts using targeted projects and data sets. Modeling and DA activities focus on demonstrating utility of NASA data sets and capabilities within operational systems. SPoRT has successfully assimilated the Atmospheric Infrared Sounder (AIRS) radiance and profile data. A collaborative project is underway with the Joint Center for Satellite Data Assimilation (JCSDA) to use AIRS profiles to better understand the impact of AIRS radiances assimilated within Gridpoint Statistical Interpolation (GSI) in hopes of engaging the operational DA community in a reassessment of assimilation methodologies to more effectively assimilate hyperspectral radiances.

  12. First continuous measurements of δ18O-CO2 in air with a Fourier transform infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Vardag, S. N.; Hammer, S.; Sabasch, M.; Griffith, D. W. T.; Levin, I.

    2015-02-01

    The continuous in situ measurement of δ18O in atmospheric CO2 opens a new door to differentiating between CO2 source and sink components with high temporal resolution. Continuous 13C-CO2 measurement systems have already been commercially available for some time, but until now, only few instruments have been able to provide a continuous measurement of the oxygen isotope ratio in CO2. Besides precise 13C/12C observations, the Fourier transform infrared (FTIR) spectrometer is also able to measure the 18O / 16O ratio in CO2, but the precision and accuracy of the measurements have not yet been evaluated. Here we present a first analysis of δ18O-CO2 (and δ13C-CO2) measurements with the FTIR analyser in Heidelberg. We used Allan deviation to determine the repeatability of δ18O-CO2 measurements and found that it decreases from 0.25‰ for 10 min averages to about 0.1‰ after 2 h and remains at that value up to 24 h. We evaluated the measurement precision over a 10-month period (intermediate measurement precision) using daily working gas measurements and found that our spectrometer measured δ18O-CO2 to better than 0.3‰ at a temporal resolution of less than 10 min. The compatibility of our FTIR-spectrometric measurements to isotope-ratio mass-spectrometric (IRMS) measurements was determined by comparing FTIR measurements of cylinder gases and ambient air with IRMS measurements of flask samples, filled with gases of the same cylinders or collected from the same ambient air intake. Two-sample t tests revealed that, at the 0.01 significance level, the FTIR and the IRMS measurements do not differ significantly from each other and are thus compatible. We describe two weekly episodes of ambient air measurements, one in winter and one in summer, and discuss what potential insights and new challenges combined highly resolved CO2, δ13C-CO2 and δ18O-CO2 records may provide in terms of better understanding regional scale continental carbon exchange processes.

  13. High Lapse Rates in AIRS Retrieved Temperatures in Cold Air Outbreaks

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Kahn, Brian; Olsen, Edward T.; Fishbein, Evan

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) experiment, on NASA's Aqua spacecraft, uses a combination of infrared and microwave observations to retrieve cloud and surface properties, plus temperature and water vapor profiles comparable to radiosondes throughout the troposphere, for cloud cover up to 70%. The high spectral resolution of AIRS provides sensitivity to important information about the near-surface atmosphere and underlying surface. A preliminary analysis of AIRS temperature retrievals taken during January 2003 reveals extensive areas of superadiabatic lapse rates in the lowest kilometer of the atmosphere. These areas are found predominantly east of North America over the Gulf Stream, and, off East Asia over the Kuroshio Current. Accompanying the high lapse rates are low air temperatures, large sea-air temperature differences, and low relative humidities. Imagery from a Visible / Near Infrared instrument on the AIRS experiment shows accompanying clouds. These lines of evidence all point to shallow convection in the bottom layer of a cold air mass overlying warm water, with overturning driven by heat flow from ocean to atmosphere. An examination of operational radiosondes at six coastal stations in Japan shows AIRS to be oversensitive to lower tropospheric lapse rates due to systematically warm near-surface air temperatures. The bias in near-surface air temperature is seen to be independent of sea surface temperature, however. AIRS is therefore sensitive to air-sea temperature difference, but with a warm atmospheric bias. A regression fit to radiosondes is used to correct AIRS near-surface retrieved temperatures, and thereby obtain an estimate of the true atmosphere-ocean thermal contrast in five subtropical regions across the north Pacific. Moving eastward, we show a systematic shift in this air-sea temperature differences toward more isothermal conditions. These results, while preliminary, have implications for our understanding of heat flow from ocean to

  14. Application of infrared radiometers for airborne detection of clear air turbulence and low level wind shear, airborne infrared low level wind shear detection test

    NASA Technical Reports Server (NTRS)

    Kuhn, P. M.

    1985-01-01

    The feasibility of infrared optical techniques for the advance detection and avoidance of low level wind shear (LLWS) or low altitude wind shear hazardous to aircraft operations was investigated. A primary feasibility research effort was conducted with infrared detectors and instrumentation aboard the NASA Ames Research Center Learjet. The main field effort was flown on the NASA-Ames Dryden B57B aircraft. The original approach visualized a forward-looking, infrared transmitting (KRS-5) window through which signals would reach the detector. The present concept of a one inch diameter light pipe with a 45 deg angled mirror enables a much simpler installation virtually anywhere on the aircraft coupled with the possibility of horizontal scanning via rotation of the forward directed mirror. Present infrared detectors and filters would certainly permit ranging and horizontal scanning in a variety of methods. CRT display technology could provide a contoured picture with possible shear intensity levels from the infrared detection system on the weather radar or a small adjunct display. This procedure shoud be further developed and pilot evaluated in a light aircraft such as a Cessna 207 or equivalent.

  15. Neural network estimation of atmospheric profiles using AIRS/IASI/AMSU data in the presence of clouds

    NASA Astrophysics Data System (ADS)

    Blackwell, William J.; Pieper, Michael; Jairam, Laura G.

    2008-12-01

    As the forthcoming launch of the NPOESS Preparatory Project (NPP) nears, pre-launch predictions of onorbit performance are of critical importance to illuminate possible emphasis areas for the intensive calibration/ validation (cal/val) period to follow launch. During this period of intensive cal/val (ICV), quick-look performance assessment tools that can analyze global data over a variety of observing conditions will also play an important role in verifying and potentially improving environmental data record (EDR) quality. In this paper, we present recent work on a fast and accurate sounding algorithm based on neural networks for use with the Cross-track Infrared Sounder (CrIS) and the Advanced Technology Microwave Sounder (ATMS) to be flown on the NPP satellite. The algorithm is being used to assess pre-launch sounding performance using proxy data (where observations from current satellite sensors are transformed spectrally and spatially to resemble CrIS and ATMS) from the Atmospheric InfraRed Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU) on the NASA Aqua satellite and the Infrared Atmospheric Sounding Interferometer (IASI) and AMSU/MHS (Microwave Humidity Sounder) on the EUMETSAT MetOp-A satellite. The algorithm is also being developed to provide a highly-accurate quick-look capability during the NPP ICV period. The present work focuses on the cloud impact on the infrared (AIRS/IASI/CrIS) radiances and explores the use of stochastic cloud clearing (SCC) mechanisms together with neural network (NN) estimation. A stand-alone statistical algorithm will be presented that operates directly on cloud-impacted AIRS/AMSU, IASI/AMSU, and CrIS/ATMS (collectively CrIMSS) data, with no need for a physical cloud clearing process. The algorithm is implemented in three stages. First, the infrared radiance perturbations due to clouds are estimated and corrected by combined processing of the infrared and microwave data using the SCC approach. The cloud clearing of

  16. AIRS Data Subsetting Service at the Goddard Earth Sciences (GES) DISC/DAAC

    NASA Technical Reports Server (NTRS)

    Vicente, Gilberto A.; Qin, Jianchun; Li, Jason; Gerasimov, Irina; Savtchenko, Andrey

    2004-01-01

    The AIRS mission, as a combination of the Atmospheric Infrared Sounder (AIRS), the Advanced Microwave Sounding Unit (AMSU) and the Humidity Sounder for Brazil (HSB), brings climate research and weather prediction into 21st century. From NASA' Aqua spacecraft, the AIRS/AMSU/HSB instruments measure humidity, temperature, cloud properties and the amounts of greenhouse gases. The AIRS also reveals land and sea- surface temperatures. Measurements from these three instruments are analyzed . jointly to filter out the effects of clouds from the IR data in order to derive clear-column air-temperature profiles and surface temperatures with high vertical resolution and accuracy. Together, they constitute an advanced operational sounding data system that have contributed to improve global modeling efforts and numerical weather prediction; enhance studies of the global energy and water cycles, the effects of greenhouse gases, and atmosphere-surface interactions; and facilitate monitoring of climate variations and trends. The high data volume generated by the AIRS/AMSU/HSB instruments and the complexity of its data format (Hierarchical Data Format, HDF) are barriers to AIRS data use. Although many researchers are interested in only a fraction of the data they receive or request, they are forced to run their algorithms on a much larger data set to extract the information of interest. In order to better server its users, the GES DISC/DAAC, provider of long-term archives and distribution services as well science support for the AIRS/AMSU/HSB data products, has developed various tools for performing channels, variables, parameter, spatial and derived products subsetting, resampling and reformatting operations. This presentation mainly describes the web-enabled subsetting services currently available at the GES DISC/DAAC that provide subsetting functions for all the Level 1B and Level 2 data products from the AIRS/AMSU/HSB instruments.

  17. The DST group ionospheric sounder replacement for JORN

    NASA Astrophysics Data System (ADS)

    Harris, T. J.; Quinn, A. D.; Pederick, L. H.

    2016-06-01

    The Jindalee Over-the-horizon Radar Network (JORN) is an integral part of Australia's national defense capability. JORN uses a real-time ionospheric model as part of its operations. The primary source of data for this model is a set of 13 vertical-incidence sounders (VIS) scattered around the Australian coast and inland locations. These sounders are a mix of Lowell digisonde portable sounder (DPS)-1 and DPS-4. Both of these sounders, the DPS-1 in particular, are near the end of their maintainable life. A replacement for these aging sounders was required as part of the ongoing sustainment program for JORN. Over the last few years the High-Frequency Radar Branch (HFRB) of the Defence Science and Technology (DST) Group, Australian Department of Defence, has been developing its own sounders based on its successful radar hardware technology. The DST Group VIS solution known as PRIME (Portable Remote Ionospheric Monitoring Equipment) is a 100% duty cycle, continuous wave system that receives the returned ionospheric signal while it is still transmitting and operates the receiver in the near field of the transmitter. Of considerable importance to a successful VIS is the autoscaling software, which takes the ionogram data and produces an ionogram trace (group delay as a function of frequency), and from that produces a set of ionospheric parameters that represent the (bottomside) overhead electron density profile. HFRB has developed its own robust autoscaling software. The performance of DST Group's PRIME under a multitude of challenging ionospheric conditions has been studied. In December 2014, PRIME was trialed at a JORN VIS site collocated with the existing Lowell Digisonde DPS-1. This side-by-side testing determined that PRIME was fit for purpose. A summary of the results of this comparison and example PRIME output will be discussed. Note that this paper compares PRIME with the 25 year old Lowell Digisonde DPS-1, which is planned to be replaced. Our future plans include

  18. Investigating Langmuir films at the air-water interface using a planar array infrared reflection-absorption spectrograph

    NASA Astrophysics Data System (ADS)

    Kim, Young Shin

    In this work, a new planar array infrared reflection-absorption spectrograph (PA-IRRAS) was developed to investigate a broad range of Langmuir films at the air-water interface. This instrument is capable of recording sample and reference spectra simultaneously with an optical setup that is the same as that of a single-beam instrument but splits the incident infrared beam into two sections on a plane mirror (H) or a water trough. With this design, the instrument could accommodate large infrared accessories, such as a water trough. In addition, water bands were subtracted to obtain a high quality spectrum for a poly(lactic acid) (PLA) Langmuir film on the water subphase with a resolution of about 8 cm-1 in 10.8 sec. With this instrument, two types of monolayer systems were studied; polymeric and lipid Langmuir films at the air-water interface. For the polymeric monolayer system, PA-IRRAS was used as a probe to follow the real-time conformational changes associated with intermolecular interactions of the polymer chains during the compression of the monolayers. It was found that the mixture of poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) (D/L) formed a stereocomplex when the mixed solution developed the two-dimensional monolayer at the air-water interface. The stereocomplexation occurred before film compression, indicating that there is no direct correlation between film compression and stereocomplexation. For the lipid monolayer system, PA-IRRAS was also used as a probe to investigate the origin of the disruption of a lipid monolayer upon protein adsorption at the air-water interface. Analysis of the time-resolved PA-IRRAS spectra revealed that Cu(II) ion-chelated DSIDA lipid monolayer (Cu 2+-DSIDA) was readily disrupted by myoglobin adsorption as demonstrated by a blue shift of 1.7 cm-1 and a lower intensity in the vas(CH2) stretch mode of the lipid monolayer over a period of five hours. To find the origin of the disruption of the lipid monolayer, a

  19. Multi-instrument gravity-wave measurements over Tierra del Fuego and the Drake Passage - Part 1: Potential energies and vertical wavelengths from AIRS, COSMIC, HIRDLS, MLS-Aura, SAAMER, SABER and radiosondes

    NASA Astrophysics Data System (ADS)

    Wright, Corwin J.; Hindley, Neil P.; Moss, Andrew C.; Mitchell, Nicholas J.

    2016-03-01

    Gravity waves in the terrestrial atmosphere are a vital geophysical process, acting to transport energy and momentum on a wide range of scales and to couple the various atmospheric layers. Despite the importance of these waves, the many studies to date have often exhibited very dissimilar results, and it remains unclear whether these differences are primarily instrumental or methodological. Here, we address this problem by comparing observations made by a diverse range of the most widely used gravity-wave-resolving instruments in a common geographic region around the southern Andes and Drake Passage, an area known to exhibit strong wave activity. Specifically, we use data from three limb-sounding radiometers (Microwave Limb Sounder, MLS-Aura; HIgh Resolution Dynamics Limb Sounder, HIRDLS; Sounding of the Atmosphere using Broadband Emission Radiometry, SABER), the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) GPS-RO constellation, a ground-based meteor radar, the Advanced Infrared Sounder (AIRS) infrared nadir sounder and radiosondes to examine the gravity wave potential energy (GWPE) and vertical wavelengths (λz) of individual gravity-wave packets from the lower troposphere to the edge of the lower thermosphere ( ˜ 100 km). Our results show important similarities and differences. Limb sounder measurements show high intercorrelation, typically > 0.80 between any instrument pair. Meteor radar observations agree in form with the limb sounders, despite vast technical differences. AIRS and radiosonde observations tend to be uncorrelated or anticorrelated with the other data sets, suggesting very different behaviour of the wave field in the different spectral regimes accessed by each instrument. Evidence of wave dissipation is seen, and varies strongly with season. Observed GWPE for individual wave packets exhibits a log-normal distribution, with short-timescale intermittency dominating over a well-repeated monthly-median seasonal

  20. AIRS Data Service at NASA Goddard Earth Sciences Data and Information Services (GES DISC) and Its Application to Climate Change Study

    NASA Astrophysics Data System (ADS)

    Won, Y.; Vollmer, B.; Theobald, M.; Hua, X.

    2008-12-01

    The Atmospheric Infrared Sounder (AIRS) instrument suite is designed to observe and characterize the entire atmospheric column from the surface to the top of the atmosphere in terms of surface emissivity and temperature, atmospheric temperature and humidity profiles, cloud amount and height, and the spectral outgoing infrared radiation on a global scale. It is comprised of a space-based hyperspectral infrared instrument (AIRS) and two multichannel microwave instruments, the Advanced Microwave Sounding Unit (AMSU-A) and the Humidity Sounder for Brazil (HSB). The AIRS instrument suite is one of several instruments onboard the Earth Observing System (EOS) Aqua spacecraft launched May 4, 2002 and has been providing global coverage ever since. A six-year record of these data are available from the GES DISC. The AIRS Data Support Team at the GES DISC provides data support to assist others in understanding, retrieving, and extracting information from the AIRS/AMSU/HSB data products. Various AIRS data products (Level-1B, Level-2 and Level-3) are available from the GES DISC. In addition, the GES DISC provides a range of value added services such as data search and access services, subsetting and format conversion services, online data visualization and analysis services. Because number of years has passed since its operation started, the amount of data has reached a certain level of maturity where we can address the climate change study utilizing the AIRS data. In this presentation, we would like to list various services we provide and to demonstrate how to utilize/apply the existing service to long-term and short term variability study.

  1. The Use of Red Green Blue Air Mass Imagery to Investigate the Role of Stratospheric Air in a Non-convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.; Molthan, A. L.

    2013-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and Rapid Refresh analyses.

  2. Organization of T-shaped facial amphiphiles at the air/water interface studied by infrared reflection absorption spectroscopy.

    PubMed

    Schwieger, Christian; Chen, Bin; Tschierske, Carsten; Kressler, Jörg; Blume, Alfred

    2012-10-11

    We studied the behavior of monolayers at the air/water interface of T-shaped facial amphiphiles which show liquid-crystalline mesophases in the bulk. The compounds are composed of a rigid p-terphenyl core (TP) with two terminal hydrophobic ether linked alkyl chains of equal length and one facial hydrophilic tri(ethylene oxide) chain with a carboxylic acid end group. Due to their amphiphilic nature they form stable Langmuir films at the air/water interface. Depending on the alkyl chain length they show markedly different compression isotherms. We used infrared reflection absorption spectroscopy (IRRAS) to study the changes in molecular organization of the TP films upon compression. We could retrieve information on layer thickness, alkyl chain crystallization, and the orientation of the TP cores within the films. Films of TPs with long (16 carbon atoms: TP 16/3) and short (10 carbon atoms: TP 10/3) alkyl chains were compared. Compression of TP 16/3 leads to crystallization of the terminal alkyl chains, whereas the alkyl chains of TP 10/3 stay fluid over the complete compression range. TP 10/3 shows an extended plateau in the compression isotherm which is due to a layering transition. The mechanism of this layering transition is discussed. Special attention was paid to the question of whether a so-called roll-over collapse occurs during compression. From the beginning to the end of the plateau, the layer thickness is increased from 15 to 38 Å and the orientation of the TP cores changes from parallel to the water surface to isotropic. We conclude that the plateau in the compression isotherm reflects the transition of a TP monolayer to a TP multilayer. The monolayer consists of a sublayer of well-organized TP cores underneath a sublayer of fluid alkyl chains whereas the multilayer consists of a well oriented bottom layer and a disordered top layer. Our findings do not support the model of a roll-over collapse. This study demonstrates how the IRRA band intensity of OH

  3. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Radiances from hyperspectral sounders such as the Atmospheric Infrared Sounder (AIRS) are routinely assimilated both globally and regionally in operational numerical weather prediction (NWP) systems using the Gridpoint Statistical Interpolation (GSI) data assimilation system. However, only thinned, cloud-free radiances from a 281-channel subset are used, so the overall percentage of these observations that are assimilated is somewhere on the order of 5%. Cloud checks are performed within GSI to determine which channels peak above cloud top; inaccuracies may lead to less assimilated radiances or introduction of biases from cloud-contaminated radiances.Relatively large footprint from AIRS may not optimally represent small-scale cloud features that might be better resolved by higher-resolution imagers like the Moderate Resolution Imaging Spectroradiometer (MODIS). Objective of this project is to "swap" the MODIS-derived cloud top pressure (CTP) for that designated by the AIRS-only quality control within GSI to test the hypothesis that better representation of cloud features will result in higher assimilated radiance yields and improved forecasts.

  4. Sensitivity of Short-Term Weather Forecasts to Assimilated AIRS Data: Implications for NPOESS Applications

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; McCarty, Will; Chou, Shih-Hung; Jedlovec, Gary

    2009-01-01

    The Atmospheric Infrared Sounder (AIRS) is acting as a heritage and risk reduction instrument for the Cross-track lnfrared Sounder (CrIS) to be flown aboard the NPP and NPOESS satellites. The hyperspectral nature of AIRS and CrIS provides high-quality soundings that, along with their asynoptic observation time over North America, make them attractive sources to fill the spatial and temporal data voids in upper air temperature and moisture measurements for use in data assimilation and numerical weather prediction. Observations from AlRS can be assimilated either as direct radiances or retrieved thermodynamic profiles, and the Short-Term Prediction Research and Transition (SPORT) Center at NASA's Marshall Space Flight Center has used both data types to improve short-term (0-48h), regional forecasts. The purpose of this paper is to share SPORT'S experiences using AlRS radiances and retrieved profiles in regional data assimilation activities by showing that proper handling of issues-including cloud contamination and land emissivity characterization-are necessary to produce optimal analyses and forecasts.

  5. Ultraspectral sounder data compression using the Tunstall coding

    NASA Astrophysics Data System (ADS)

    Wei, Shih-Chieh; Huang, Bormin; Gu, Lingjia

    2007-09-01

    In an error-prone environment the compression of ultraspectral sounder data is vulnerable to error propagation. The Tungstall coding is a variable-to-fixed length code which compresses data by mapping a variable number of source symbols to a fixed number of codewords. It avoids the resynchronization difficulty encountered in fixed-to-variable length codes such as Huffman coding and arithmetic coding. This paper explores the use of the Tungstall coding in reducing the error propagation for ultraspectral sounder data compression. The results show that our Tunstall approach has a favorable compression ratio compared with JPEG-2000, 3D SPIHT, JPEG-LS, CALIC and CCSDS IDC 5/3. It also has less error propagation compared with JPEG-2000.

  6. SAR/InSAR observation by an HF sounder

    NASA Astrophysics Data System (ADS)

    Kobayashi, T.; Ono, T.

    2007-03-01

    Application of SAR imaging algorithm to spaceborne HF sounder observation was studied. Two types of image ambiguity problems were addressed in the application. One is surface/subsurface image ambiguity arising from deep penetration of HF wave, and another is mirror image ambiguity that is inherent to dipole antenna SAR. A numerical model demonstrated that the surface/subsurface ambiguity can be mitigated by taking a synthetic aperture large enough to defocus subsurface objects. In order to resolve the mirror image ambiguity problem, an image superposition technique was proposed. The performance of the technique was demonstrated by using simulation data of the HF sounder observation to confirm the feasibility of HF SAR and HF InSAR observation.

  7. The topside sounder database - Data screening and systematic biases

    NASA Astrophysics Data System (ADS)

    Verhulst, Tobias; Stankov, Stanimir M.

    2013-06-01

    The ionospheric topside sounder measurement database developed at the US National Space Science Data Center (NSSDC) is a valuable source of information when investigating the composition and complex dynamics of the upper ionosphere. The database is increasingly used by many scientists around the world for both research and development of empirical models. However, there is always a danger of indiscriminately using the data without properly assessing the data quality and applicability for a given purpose. This paper is concerned with the issue of data screening and pre-processing of the Alouette/ISIS topside sounder database. An overview of the original database availability and formatting is given and the use of solar and geomagnetic indices is discussed. Data screening procedures, concerning detection and handling of erroneous profiles, are also presented. Special attention is drawn to the systematic biases observed in the database and the possibilities for their removal.

  8. HIS analyses of mesoscale phenomena. [High resolution Interferometer Sounder

    NASA Technical Reports Server (NTRS)

    Bradshaw, John T.; Fuelberg, Henry E.

    1990-01-01

    Results are presented from two sets of measurements made by the High-resolution Interferometer Sounder (HIS) during two aircraft flights over the Cooperative-Huntsville-Meteorological-Experiment region on June 15 and 19, 1986. It is shown that the temperature and the dew-point field retrieved from HIS spectra contain distinct mesoscale structures. The features in the HIS dew-point fields agreed well with the cloud and moisture structures observed in visible and 6.7 micron GOES imagery.

  9. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 1

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) an instrument overview; (2) an instrument description; (3) the instrument's conceptual design; (4) technical risks and offsets; (5) instrument reliability; (6) commands and telemetry; (7) mass and power budgets; (8) integration and test program; (9) program implementation; and (10) phase CD schedule.

  10. The Apollo 17 Lunar Sounder. [lunar orbit coherent radar experiment

    NASA Technical Reports Server (NTRS)

    Phillips, R. J.; Brown, W. E., Jr.; Jordan, R.; Adams, G. F.; Jackson, P.; Peeples, W. J.; Porcello, L. J.; Ryu, J.; Eggleton, R. E.; Schaber, G.

    1973-01-01

    The Apollo Lunar Sounder Experiment, a coherent radar operated from lunar orbit during the Apollo 17 mission, has scientific objectives of mapping lunar subsurface structure, surface profiling, surface imaging, and galactic noise measurement. Representative results from each of the four disciplines are presented. Subsurface reflections have been interpreted in both optically and digitally processed data. Images and profiles yield detailed selenomorphological information. The preliminary galactic noise results are consistent with earlier measurements by other workers.

  11. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) preliminary program plans; (2) contract end item (CEI) specification; and (3) the instrument interface description document. Under the preliminary program plans section, plans dealing with the following subject areas are discussed: spares, performance assurance, configuration management, software implementation, contamination, calibration management, and verification.

  12. Intercomparison of stratospheric gravity wave observations with AIRS and IASI

    NASA Astrophysics Data System (ADS)

    Hoffmann, Lars; Alexander, M. Joan; Clerbaux, Cathy; Grimsdell, Alison W.; Meyer, Catrin I.; Rößler, Thomas; Tournier, Bernard

    2015-04-01

    Gravity waves are an important driver for the atmospheric circulation and have substantial impact on weather and climate. Satellite instruments offer excellent opportunities to study gravity waves on a global scale. This study focuses on observations from the Atmospheric Infrared Sounder (AIRS) onboard the National Aeronautics and Space Administration's Aqua satellite and the Infrared Atmospheric Sounding Interferometer (IASI) onboard the European MetOp satellites. The main aim of this study is an intercomparison of stratospheric gravity wave observations of both instruments. In particular, we analyzed AIRS and IASI 4.3 μm brightness temperature measurements, which directly relate to stratospheric temperature. Three case studies showed that AIRS and IASI provide a clear and consistent picture of the temporal development of individual gravity wave events. Statistical comparisons based on a five-year period of measurements (2008 - 2012) showed similar spatial and temporal patterns of gravity wave activity. However, the statistical comparisons also revealed systematic differences of variances between AIRS and IASI that we attribute to the different spatial measurement characteristics of both instruments. We also found differences between day- and nighttime data that are partly due to the local time variations of the gravity wave sources. While AIRS has been used successfully in many previous gravity wave studies, IASI data are applied here for the first time for that purpose. Our study shows that gravity wave observations from different hyperspectral infrared sounders such as AIRS and IASI can be directly related to each other, if instrument-specific characteristics such as different noise levels and spatial resolution and sampling are carefully considered. The ability to combine observations from different satellites provides an opportunity to create a long-term record, which is an exciting prospect for future climatological studies of stratospheric gravity wave

  13. Observational Sensitivity to Climate Variability using AIRS/Aqua and MERRA

    NASA Astrophysics Data System (ADS)

    Hearty, T. J.; Fetzer, E.; Tian, B.; Yung, Y. L.; Vollmer, B.; Savtchenko, A. K.; Smith, P. M.; Theobald, M.; Ostrenga, D.

    2011-12-01

    The El Nino Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) are two of the largest climate variabilities seen in AIRS observations of temperature, water vapor, and clouds. Numerous climate feedbacks are involved in these oscillations. We examine these oscillations using observations from the Atmospheric Infrared Sounder (AIRS) and the Modern Era Retrospective-Analysis for Research and Applications (MERRA). Since sampling can be an issue for infrared satellites in low earth orbit, we examine the MERRA data sampled at the AIRS space-time locations both with and without the AIRS quality control. We estimate the sampling bias of an AIRS climatology and the atmospheric conditions where AIRS has a lower sampling rate and examine the apparent differences in the ENSO and NAO based on the different sampling. While the AIRS temperature and water vapor sampling biases are small at low latitudes, they can be more than a few degrees in temperature and 10 percent in water vapor at higher latitudes. While these numbers are small they can be important for understanding climate variability.

  14. A Module for Assimilating Hyperspectral Infrared Retrieved Profiles into the Gridpoint Statistical Interpolation System for Unique Forecasting Applications

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Srikishen, Jayanthi; Blankenship, Clay

    2015-01-01

    Hyperspectral infrared sounder radiance data are assimilated into operational modeling systems however the process is computationally expensive and only approximately 1% of available data are assimilated due to data thinning as well as the fact that radiances are restricted to cloud-free fields of view. In contrast, the number of hyperspectral infrared profiles assimilated is much higher since the retrieved profiles can be assimilated in some partly cloudy scenes due to profile coupling other data, such as microwave or neural networks, as first guesses to the retrieval process. As the operational data assimilation community attempts to assimilate cloud-affected radiances, it is possible that the use of retrieved profiles might offer an alternative methodology that is less complex and more computationally efficient to solve this problem. The NASA Short-term Prediction Research and Transition (SPoRT) Center has assimilated hyperspectral infrared retrieved profiles into Weather Research and Forecasting Model (WRF) simulations using the Gridpoint Statistical Interpolation (GSI) System. Early research at SPoRT demonstrated improved initial conditions when assimilating Atmospheric Infrared Sounder (AIRS) thermodynamic profiles into WRF (using WRF-Var and assigning more appropriate error weighting to the profiles) to improve regional analysis and heavy precipitation forecasts. Successful early work has led to more recent research utilizing WRF and GSI for applications including the assimilation of AIRS profiles to improve WRF forecasts of atmospheric rivers and assimilation of AIRS, Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI) profiles to improve model representation of tropopause folds and associated non-convective wind events. Although more hyperspectral infrared retrieved profiles can be assimilated into model forecasts, one disadvantage is the retrieved profiles have traditionally been assigned the

  15. Comparison of Gravity Wave Temperature Variances from Ray-Based Spectral Parameterization of Convective Gravity Wave Drag with AIRS Observations

    NASA Technical Reports Server (NTRS)

    Choi, Hyun-Joo; Chun, Hye-Yeong; Gong, Jie; Wu, Dong L.

    2012-01-01

    The realism of ray-based spectral parameterization of convective gravity wave drag, which considers the updated moving speed of the convective source and multiple wave propagation directions, is tested against the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. Offline parameterization calculations are performed using the global reanalysis data for January and July 2005, and gravity wave temperature variances (GWTVs) are calculated at z = 2.5 hPa (unfiltered GWTV). AIRS-filtered GWTV, which is directly compared with AIRS, is calculated by applying the AIRS visibility function to the unfiltered GWTV. A comparison between the parameterization calculations and AIRS observations shows that the spatial distribution of the AIRS-filtered GWTV agrees well with that of the AIRS GWTV. However, the magnitude of the AIRS-filtered GWTV is smaller than that of the AIRS GWTV. When an additional cloud top gravity wave momentum flux spectrum with longer horizontal wavelength components that were obtained from the mesoscale simulations is included in the parameterization, both the magnitude and spatial distribution of the AIRS-filtered GWTVs from the parameterization are in good agreement with those of the AIRS GWTVs. The AIRS GWTV can be reproduced reasonably well by the parameterization not only with multiple wave propagation directions but also with two wave propagation directions of 45 degrees (northeast-southwest) and 135 degrees (northwest-southeast), which are optimally chosen for computational efficiency.

  16. Ambient formic acid in southern California air: A comparison of two methods, Fourier transform infrared spectroscopy and alkaline trap-liquid chromatography with UV detection

    SciTech Connect

    Grosjean, D. ); Tuazon, E.C. ); Fujita, E. )

    1990-01-01

    Formic acid is an ubiquitous component of urban smog. Sources of formic acid in urban air include direct emissions from vehicles and in situ reaction of ozone with olefins. Ambient levels of formic acid in southern California air were first measured some 15 years ago by Hanst et al. using long-path Fourier transform infrared spectroscopy (FTIR). All subsequent studies of formic acid in the Los Angeles area have involved the use of two methods, either FTIR or collection on alkaline traps followed by gas chromatography, ion chromatography, or liquid chromatography analysis with UV detection, ATLC-UV. The Carbon Species Methods Comparison Study (CSMCS), a multilaboratory air quality study carried out in August 1986 at a southern California smog receptor site, provided an opportunity for direct field comparison of the FTIR and alkaline trap methods. The results of the comparison are presented in this brief report.

  17. Subminiature infrared detector translation stage

    NASA Technical Reports Server (NTRS)

    Bell, Alan D.

    1989-01-01

    This paper describes a precision subminiature three-axis translation stage used in the GOES Sounder to provide positional adjustment of 12 cooled infrared detectors. Four separate translation stages and detectors are packaged into a detector mechanism which has an overall size of 0.850 x 1.230 x 0.600 inches. Each translation stage is capable of + or - 0.015 inch motion in the X and Y axes and +0.050/-0.025 inch motion in the Z axis with a sensitivity of 0.0002 inches. The function of the detector translation stage allows real time detector signal peaking during Sounder alignment. The translation stage operates in a cryogenic environment under a 10 to the -6th torr vacuum.

  18. Sounder updates for statistical model predictions of maximum usable frequencies on HF sky wave paths

    NASA Astrophysics Data System (ADS)

    Reilly, Michael H.; Daehler, Mark

    1986-12-01

    A method is presented for the short-term prediction of maximum usable frequencies (MUFs) in a large communications region. It is shown how ionospheric measurements from a network of ionospheric sounders can be used to update sunspot number or solar 10.7 cm flux inputs to a climatological MUF prediction model. MINIMUF in this case, which is then used to predict MUFs on paths throughout the region. Analysis of mid-latitude oblique-incidence sounder data sets indicates the advantage gained from single-path sounder updates of flux for MUF predictions on adjacent paths. Under specified conditions a further dramatic improvement in MUF prediction accuracy is found from spatial interpolation of sounder-updated flux values. MUF prediction accuracies within 0.5 MHz are obtained for fairly modest sounder network deployments, in which the sounder midpath point distributions and updating frequency satisfy particular requirements.

  19. Compressive Earth observatory: An insight from AIRS/AMSU retrievals

    NASA Astrophysics Data System (ADS)

    Ebtehaj, Ardeshir M.; Foufoula-Georgiou, Efi; Lerman, Gilad; Bras, Rafael L.

    2015-01-01

    We demonstrate that the global fields of temperature, humidity, and geopotential heights admit a nearly sparse representation in the wavelet domain, offering a viable path forward to explore new paradigms of sparsity-promoting data assimilation and compressive recovery of land surface-atmospheric states from space. We illustrate this idea using retrieval products of the Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU) on board the Aqua satellite. The results reveal that the sparsity of the fields of temperature is relatively pressure independent, while atmospheric humidity and geopotential heights are typically sparser at lower and higher pressure levels, respectively. We provide evidence that these land-atmospheric states can be accurately estimated using a small set of measurements by taking advantage of their sparsity prior.

  20. The Impact of the AIRS Spatial Response on Channel-to-Channel and Multi-Instrument Data Analyses

    NASA Technical Reports Server (NTRS)

    Elliott, Denis A.; Pagano, Thomas S.; Aumann, H. H.

    2006-01-01

    The Atmospheric Infrared Sounder (AIRS) measures the infrared spectrum in 2378 channels between 3.7 and 15.4 microns with a very high spectral resolution of approximately 1200. AIRS footprints are approximately 1.1 by 0.6 degrees. Because AIRS is a grating spectrometer, each channel has a unique spatial response. Image rotation due to the scan mirror causes these spatial responses to rotate. In effect, each channel has 90 spatial responses, one for each scene footprint in the scan line. Although the spatial response for most channels is symmetric and nearly uniform, some channels have significantly asymmetric response. This paper reviews and describes the prelaunch measurements that characterized the spatial response functions. Next, it describes the conversion of the ground-based results into footprint-specific response functions valid in flight. Then we describe the postlaunch validation of the measurements, including centroid location, axes orientations, and a check on the full two-dimensional response functions. This latter check involves comparison of AIRS data with that of the Moderate Resolution Imaging Spectrometer (MODIS), which flies on the same platform as AIRS. An important result is that AIRS/MODIS brightness temperature comparisons are significantly improved (scatter reduced) when the AIRS spatial response is explicitly taken into account. Finally, a status report is given on attempts to fully verify the prelaunch measurements by deriving the AIRS spatial response from flight data alone.

  1. Analysis of test data film generated by the lunar sounder (S-209)

    NASA Technical Reports Server (NTRS)

    Massey, N.

    1973-01-01

    The analysis of test films pertaining to the readiness of the Apollo 17 radar equipment is discussed. Emphasis is placed on the evaluation of the lunar sounder equipment. The lunar sounder experiment was to examine the lunar surface at three different radar frequencies of 2 meters, 60 meters, and 20 meters. Test films were made on the lunar sounder system to describe the purpose of the test, to describe the experiments used for analysis, and to provide conclusions reached after analysis.

  2. Retrieval of the Nitrous Oxide Profiles using the AIRS Data in China

    NASA Astrophysics Data System (ADS)

    Chen, L.; Ma, P.; Tao, J.; Li, X.; Zhang, Y.; Wang, Z.; Li, S.; Xiong, X.

    2014-12-01

    As an important greenhouse gas and ozone-depleting substance, the 100-year global warming potential of Nitrous Oxide (N2O) is almost 300 times higher than that of carbon dioxide. However, there are still large uncertainties about the quantitative N2O emission and its feedback to climate change due to the coarse ground-based network. This approach attempts to retrieve the N2O profiles from the Atmospheric InfraRed Sounder (AIRS) data. First, the sensitivity of atmospheric temperature and humidity profiles and surface parameters between two spectral absorption bands were simulated by using the radiative transfer model. Second, the eigenvector regression algorithm is used to construct a priori state. Third, an optimal estimate method was developed based on the band selection of N2O. Finally, we compared our retrieved AIRS profiles with HIPPO data, and analyzed the seasonal and annual N2O distribution in China from 2004 to 2013.

  3. Midtropospheric CO2 concentration retrieval from AIRS observations in the tropics

    NASA Astrophysics Data System (ADS)

    Crevoisier, C.; Heilliette, S.; Chédin, A.; Serrar, S.; Armante, R.; Scott, N. A.

    2004-09-01

    Midtropospheric carbon dioxide (CO2) concentration is retrieved in the tropics [20S:20N], over sea, at night, for the period April to October 2003 from the Atmospheric Infrared Sounder (AIRS) observations. The method relies on a non-linear regression inference scheme using neural networks. A rough estimate of the mean precision of the method is about 2.5 ppmv (0.7%). The retrieved seasonal cycle and its latitudinal dependence agree well with aircraft CO2 in situ measurements made at the same altitude range. Maps produced on a monthly basis at a resolution of 15° × 15°, although not yet fully understood, show good agreement with known characteristics of CO2 distribution reflecting both atmospheric transport and surface fluxes (fossil fuel emissions, biomass burning, air-surface gas exchanges).

  4. Synergistic use of AIRS and MODIS for dust top height retrieval over land

    NASA Astrophysics Data System (ADS)

    Yao, Zhigang; Li, Jun; Zhao, Zengliang

    2015-04-01

    It is nontrivial to extract the dust top height (DTH) accurately from passive instruments over land due to the complexity of the surface conditions. The Moderate Resolution Imaging Spectroradiometer (MODIS) deep blue (DB) algorithm can be used to infer the aerosol optical depth (AOD) over high-reflective surfaces. The Atmospheric Infrared Sounder (AIRS) can simultaneously obtain the DTH and optical depth information. This study focuses on the synergistic use of AIRS observations and MODIS DB results for improving the DTH by using a stable relationship between the AIRS infrared and MODIS DB AODs. A one-dimensional variational (1DVAR) algorithm is applied to extract the DTH from AIRS. Simulation experiments indicate that when the uncertainty of the dust optical depth decreases from 50% to 20%, the improvement of the DTH retrieval accuracy from AIRS reaches 200 m for most of the assumed dust conditions. For two cases over the Taklimakan Desert, the results are compared against Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements. The results confirm that the MODIS DB product could help extract the DTH over land from AIRS.

  5. Improving forecast skill by assimilation of quality-controlled AIRS temperature retrievals under partially cloudy conditions

    NASA Astrophysics Data System (ADS)

    Reale, O.; Susskind, J.; Rosenberg, R.; Brin, E.; Liu, E.; Riishojgaard, L. P.; Terry, J.; Jusem, J. C.

    2008-04-01

    The National Aeronautics and Space Administration (NASA) Atmospheric Infrared Sounder (AIRS) on board the Aqua satellite is now recognized as an important contributor towards the improvement of weather forecasts. At this time only a small fraction of the total data produced by AIRS is being used by operational weather systems. In fact, in addition to effects of thinning and quality control, the only AIRS data assimilated are radiance observations of channels unaffected by clouds. Observations in mid-lower tropospheric sounding AIRS channels are assimilated primarily under completely clear-sky conditions, thus imposing a very severe limitation on the horizontal distribution of the AIRS-derived information. In this work it is shown that the ability to derive accurate temperature profiles from AIRS observations in partially cloud-contaminated areas can be utilized to further improve the impact of AIRS observations in a global model and forecasting system. The analyses produced by assimilating AIRS temperature profiles obtained under partial cloud cover result in a substantially colder representation of the northern hemisphere lower midtroposphere at higher latitudes. This temperature difference has a strong impact, through hydrostatic adjustment, in the midtropospheric geopotential heights, which causes a different representation of the polar vortex especially over northeastern Siberia and Alaska. The AIRS-induced anomaly propagates through the model's dynamics producing improved 5-day forecasts.

  6. Improving Forecast Skill by Assimilation of Quality-controlled AIRS Temperature Retrievals under Partially Cloudy Conditions

    NASA Technical Reports Server (NTRS)

    Reale, O.; Susskind, J.; Rosenberg, R.; Brin, E.; Riishojgaard, L.; Liu, E.; Terry, J.; Jusem, J. C.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Atmospheric Infrared Sounder (AIRS) on board the Aqua satellite has been long recognized as an important contributor towards the improvement of weather forecasts. At this time only a small fraction of the total data produced by AIRS is being used by operational weather systems. In fact, in addition to effects of thinning and quality control, the only AIRS data assimilated are radiance observations of channels unaffected by clouds. Observations in mid-lower tropospheric sounding AIRS channels are assimilated primarily under completely clear-sky conditions, thus imposing a very severe limitation on the horizontal distribution of the AIRS-derived information. In this work it is shown that the ability to derive accurate temperature profiles from AIRS observations in partially cloud-contaminated areas can be utilized to further improve the impact of AIRS observations in a global model and forecasting system. The analyses produced by assimilating AIRS temperature profiles obtained under partial cloud cover result in a substantially colder representation of the northern hemisphere lower midtroposphere at higher latitudes. This temperature difference has a strong impact, through hydrostatic adjustment, in the midtropospheric geopotential heights, which causes a different representation of the polar vortex especially over northeastern Siberia and Alaska. The AIRS-induced anomaly propagates through the model's dynamics producing improved 5-day forecasts.

  7. ABOVE03, The 2003 AIRS BBAERI Ocean Validation Experiment: AIRS Validation and Aerosols

    NASA Astrophysics Data System (ADS)

    McMillan, W. W.; Hoff, R.; Strow, L. L.; Desouza-Machado, S.; Lightner, K.; McCourt, M. L.; Maddy, E.; Kolb, N.; McCann, K.; Comer, J.; Russo, F.; Rutledge, C. K.

    2003-12-01

    From May 28 to July 9, 2003, a complementary set of instruments was deployed to the United States Coast Guard (USCG) Chesapeake Light lighthouse platform to provide correlative measurements characterizing the atmosphere and sea surface over the ocean for validation of NASA's Atmospheric InfraRed Sounder (AIRS) onboard the Aqua satellite. Located 25 km due east of Virginia Beach, VA, Chesapeake Light offers a relatively convenient site for measurements over the ocean while being far enough offshore for water only AIRS fields of view. In addition to the UMBC Baltimore Bomem Atmospheric Emitted Radiance Interferometer (BBAERI), the UMBC Elastic Lidar Facility (ELF), and Vaisala RS-90 rawinsondes used during ABOVE02, we deployed in situ O3 and CO gas analyzers and during the first three weeks, flew 18 ozonesondes in collaboration with Dr. Mike Newchurch, UAH. A total of 140 Vaisala RS-90 radiosondes were launched covering 61 Aqua and 12 Terra overpasses. Preliminary comparisons of ABOVE03 data products to AIRS observations and retrievals will be presented. Particular attention will be paid to both AIRS and ground-based aerosol observations.

  8. Low Cost Upper Atmosphere Sounder (LOCUS)

    NASA Astrophysics Data System (ADS)

    Gerber, Daniel; Swinyard, Bruce M.; Ellison, Brian N.; Aylward, Alan D.; Aruliah, Anasuya; Plane, John M. C.; Feng, Wuhu; Saunders, Christopher; Friend, Jonathan; Bird, Rachel; Linfield, Edmund H.; Davies, A. Giles; Parkes, Steve

    2014-05-01

    The Mesosphere - Lower Thermosphere region (MLT) is often quoted as being the least well known region of the atmosphere, meaning that measurements of this altitude range are sparser than for the neighbouring layers. The reason for this apparent lack of observations can be traced back to a combination of two facts - A) the MLT is ill suited for in-situ sampling on a global scale because the residual air drag is prohibitive for suborbital vehicles (rockets are traditionally used to sample the MLT region, but they only provide snapshot measurements both geographically, as well as temporally), and B) Some of the most important trace gases in the MLT have spectral emission lines in the THz range, a frequency band which has only just become accessible to conventional remote sensing technologies (i.e. passive heterodyne detection) thanks to ongoing technology development, but which still poses massive - often prohibitive - demands on the complexity, weight and power consumption of satellite borne remote sensing detectors. To mitigate the substantial power requirements of a Local Oscillator (LO) able to pump a heterodyne receiver at THZ frequencies, we are suggesting the use of Quantum Cascade Laser diodes (QCL). Combining a QCL LO with a sub-harmonic Schottky mixer in an integrated receiver system would allow us to build a THz passive heterodyne detector for atmospheric remote sensing that is both very compact and power efficient, and could therefore be built and launched much more cheaply than competitive systems. Many of the technologies required for such an instrument already exist at technology readiness levels (TRL) of 3-5. A consortium of RAL Space, University College London (UCL), University of Leeds, Surrey Satellite Technology Ltd (SSTL) and STAR-Dundee have been awarded a grant through the ESA In Orbit Demonstration Programme (IOD) to start developing an integrated, sub-harmonic heterodyne receiver with a QCL LO up to a TRL that would allow IOD hopefully in the

  9. Observations and trends of clouds based on GOES sounder data

    NASA Astrophysics Data System (ADS)

    Schreiner, Anthony J.; Schmit, Timothy J.; Menzel, W. Paul

    2001-01-01

    A 26 month (November 1997 through December 1999) data set of Geostationary Operational Environmental Satellite (GOES) sounder-derived cloud parameters has been analyzed to discern annual and monthly trends. An important outcome of this study is the identification of diurnal trends made possible by the geostationary satellite frequent observations over specific locations. The area of coverage is 20°N to 50°N and 60°W to 160°W, which corresponds to the continental United States and the surrounding waters. The satellite cloud observations were compared to manually observed Pilot Reports (PIREPs) and were found to be, on average, 35 hPa lower. Comparing the frequency of GOES sounder observations of high cloudiness with observations from the National Oceanic and Atmospheric Administration (NOAA) series of polar orbiting weather satellites reveals a correlation coefficient of 0.79 and a bias of 3.4% for the frequency of occurrence (GOES with a mean higher height). The frequency of occurrence and distribution of clouds, cloud top pressure (CTOP), and effective cloud amount are based on a spatial resolution of ˜40 km (3×3 field of view box) and are shown for eight regions. High clouds (CTOP ≤300 hPa) are found to be more prevalent during the Northern Hemisphere summer than winter for all regions. High clouds for 1998 comprise 8.5% of all observations. Also, in 1998 clear conditions are observed ˜34% of the time. Focusing on the strength of the hourly GOES sounder data, it is found that thin high clouds are most prevalent during the summer and fall seasons, occurring most frequently in the late morning and early afternoon.

  10. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA's Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Previously, it has been shown that cloud top designation associated with quality control procedures within the Gridpoint Statistical Interpolation (GSI) system used operationally by a number of Joint Center for Satellite Data Assimilation (JCSDA) partners may not provide the best representation of cloud top pressure (CTP). Because this designated CTP determines which channels are cloud-free and, thus, available for assimilation, ensuring the most accurate representation of this value is imperative to obtaining the greatest impact from satellite radiances. This paper examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing analysis increments and numerical forecasts generated using operational techniques with a research technique that swaps CTP from the Moderate-resolution Imaging Spectroradiometer (MODIS) for the value of CTP calculated from the radiances within GSI.

  11. Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Folmer, M. J.; Jedlovec, G. J.

    2014-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), 32-km North American Regional Reanalysis (NARR) interpolated to a 12-km grid, and 13-km Rapid Refresh analyses.

  12. Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, E. B.; Zavodsky, B. T.; Jedlovec, G. J.

    2014-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and Rapid Refresh analyses.

  13. Impact of the Assimilation of Hyperspectral Infrared Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, Emily B.; Zavodsky, Bradley T; Jedlovec, Gary J.; Elmer, Nicholas J.

    2013-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), North American Regional Reanalysis (NARR) reanalysis, and Rapid Refresh analyses.

  14. The Impact of the Assimilation of Hyperspectral Infrared Retrieved Profiles on Advanced Weather and Research Model Simulations of a Non-Convective Wind Event

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary; Elmer, Nicholas

    2013-01-01

    Non-convective wind events commonly occur with passing extratropical cyclones and have significant societal and economic impacts. Since non-convective winds often occur in the absence of specific phenomena such as a thunderstorm, tornado, or hurricane, the public are less likely to heed high wind warnings and continue daily activities. Thus non-convective wind events result in as many fatalities as straight line thunderstorm winds. One physical explanation for non-convective winds includes tropopause folds. Improved model representation of stratospheric air and associated non-convective wind events could improve non-convective wind forecasts and associated warnings. In recent years, satellite data assimilation has improved skill in forecasting extratropical cyclones; however errors still remain in forecasting the position and strength of extratropical cyclones as well as the tropopause folding process. The goal of this study is to determine the impact of assimilating satellite temperature and moisture retrieved profiles from hyperspectral infrared (IR) sounders (i.e. Atmospheric Infrared Sounder (AIRS), Cross-track Infrared and Microwave Sounding Suite (CrIMSS), and Infrared Atmospheric Sounding Interferometer (IASI)) on the model representation of the tropopause fold and an associated high wind event that impacted the Northeast United States on 09 February 2013. Model simulations using the Advanced Research Weather Research and Forecasting Model (ARW) were conducted on a 12-km grid with cycled data assimilation mimicking the operational North American Model (NAM). The results from the satellite assimilation run are compared to a control experiment (without hyperspectral IR retrievals), Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis, and Rapid Refresh analyses.

  15. Terahertz sensor for air pollution monitoring from spacecraft

    NASA Astrophysics Data System (ADS)

    You, Rui; Guo, Aiyan

    2016-07-01

    Terahertz wave is a radio wave which wavelength between infrared and microwave, substantial is from 0.1-1mm that is 300-3000GHz(0.3-3THz). Compare to microwave and visible/infrared it is advantage of resolution and better penetration in atmosphere respectively, and because of wavelength is similar to scale of micro-particle of air pollution, the absorption coefficient due to the many relevant molecules have a maximum signature in the THz region, such as SO2、CH4、H2S、NH3、CO、O3 etc. of molecules of polluted atmosphere . This paper present a conceptional solution of THz sensor for air pollution sounder which using of large aperture antenna and FSS with 15 channels in 0.183-1.5THz region, each channel with 2MHz by extreme narrow band filter for detecting signature of polluted air. Analysis data show that 2Km spatial resolution at 700km altitude orbit. Sensitive is about 10-12W/Hz1/2 level at cryogenic temp.

  16. AIRS Data Support at NASA Goddard Earth Science DISC DAAC

    NASA Astrophysics Data System (ADS)

    Cho, S.; Qin, J.; Sharma, A.

    2002-05-01

    The Atmospheric Infrared Sounder (AIRS) is selected by NASA to fly on the second Earth Observing System (EOS) polar orbiting platform, EOS Aqua, which is launched in April 2002. AIRS, together with Advanced Microwave Sounding Unit (AMSU) and Humidity Sounder for Brazil (HSB), is designed to meet the requirements of the NASA Earth Science Enterprise climate research program and the NOAA operational weather forecasting The data products from the AIRS/AMSU/HSB will be archived and distributed at the Goddard Distributed Active Archive Center (GDAAC) located in the NASA Goddard Earth Sciences Data and Information Services Center (GES DAAC) in later 2002. This new dataset consists of radiances, geo-locations and atmospheric products, such as, temperature, humidity, cloud and ozone, providing measurements for temperature at an accuracy of 1 o C in layers 1 km thick and humidity with an accuracy of 20 % in layers 2 km thick in the troposphere. The data will be freely available via WWW interfaces, or an FTP containing subsetted and reformatted data products. The GES DISC DAAC Search and Order allows users to search for data by following particular paths down the hierarchy. This simple point-and- click navigational web interface shows temporal and spatial coverage, item size, description and browse images for AIRS data and one can customize search using spatial,temporal, attribute and parameter search. The EOS Data Gateway (EDG) is another user interface for searching and ordering the AIRS data together with other data products obtained from EOS instruments. The Atmospheric Dynamics Data Support Team (ADDST) at the GES DISC/DAAC will provide various services to assist users in understanding, accessing, and using AIRS data product. The ADDST has been developing tools to read, visualize and analyze the AIRS data, channel/parameter subsetting of AIRS HDF-EOS data products and supplying documentation and readme et al. Other services provided by the ADDST will contain assistance

  17. The AIRS Applications Pipeline, from Identification to Visualization to Distribution

    NASA Astrophysics Data System (ADS)

    Ray, S. E.; Pagano, T. S.; Fetzer, E. J.; Lambrigtsen, B.; Teixeira, J.

    2014-12-01

    The Atmospheric Infrared Sounder (AIRS) on NASA's Aqua spacecraft has been returning daily global observations of Earth's atmospheric constituents and properties since 2002. AIRS provides observations of temperature and water vapor along the atmospheric column and is sensitive to many atmospheric constituents in the mid-troposphere, including carbon monoxide, carbon dioxide and ozone. With a 12-year data record and daily, global observations in near real-time, we are finding that AIRS data can play a role in applications that fall under most of the NASA Applied Sciences focus areas. Currently in development are temperature inversion maps that can potentially correlate to respiratory health problems, dengue fever and West Nile virus outbreak prediction maps, maps that can be used to make assessments of air quality, and maps of volcanic ash burden. This poster will communicate the Project's approach and efforts to date of its applications pipeline, which includes identifying applications, utilizing science expertise, hiring outside experts to assist with development and dissemination, visualization along application themes, and leveraging existing NASA data frameworks and organizations to facilitate archiving and distribution. In addition, a new web-based browse tool being developed by the AIRS Project for easy access to application product imagery will also be described.

  18. The Behm Acoustic Sounder for Airplanes with Reference to Its Accuracy

    NASA Technical Reports Server (NTRS)

    Schreiber, Ernest

    1930-01-01

    Relative altimetry is of great importance for increasing the safety in aerial transportation, because it makes possible safe flying at night, by poor visibility, and when landing. Among the instruments of this type is the Behm sounder, which operates on an acoustic principle. Acoustic altimetry in general and the Behn sounder, in particular, are covered in this report.

  19. Collaborative Testing of Methods to Measure Air Pollutants, II. The Non-Dispersive Infrared Method for Carbon Monoxide

    ERIC Educational Resources Information Center

    McKee, Herbert C.; And Others

    1973-01-01

    The Methods Standardization Branch of the Environmental Protection Agency, National Environmental Research Center, has undertaken a program to standardize methods used in measuring air pollutants covered by the national primary and secondary air quality standards. This paper presents the results of a collective test of the method specified for…

  20. LAWS (Laser Atmospheric Wind Sounder) earth observing system

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Wind profiles can be measured from space using current technology. These wind profiles are essential for answering many of the interdisciplinary scientific questions to be addressed by EOS, the Earth Observing System. This report provides guidance for the development of a spaceborne wind sounder, the Laser Atmospheric Wind Sounder (LAWS), discussing the current state of the technology and reviewing the scientific rationale for the instrument. Whether obtained globally from the EOS polar platform or in the tropics and subtropics from the Space Station, wind profiles from space will provide essential information for advancing the skill of numerical weather prediction, furthering knowledge of large-scale atmospheric circulation and climate dynamics, and improving understanding of the global biogeochemical and hydrologic cycles. The LAWS Instrument Panel recommends that it be given high priority for new instrument development because of the pressing scientific need and the availability of the necessary technology. LAWS is to measure wind profiles with an accuracy of a few meters per second and to sample at intervals of 100 km horizontally for layers km thick.

  1. Spectral Cloud-Filtering of AIRS Data: Non-Polar Ocean

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, David; Barron, Diana

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) is a grating array spectrometer which covers the thermal infrared spectral range between 640 and 1700/cm. In order to retain the maximum radiometric accuracy of the AIRS data, the effects of cloud contamination have to be minimized. We discuss cloud filtering which uses the high spectral resolution of AIRS to identify about 100,000 of 500,000 non-polar ocean spectra per day as relatively "cloud-free". Based on the comparison of surface channels with the NCEP provided global real time sst (rtg.sst), AIRS surface sensitive channels have a cold bias ranging from O.5K during the day to 0.8K during the night. Day and night spatial coherence tests show that the cold bias is due to cloud contamination. During the day the cloud contamination is due to a 2-3% broken cloud cover at the 1-2 km altitude, characteristic of low stratus clouds. The cloud-contamination effects surface sensitive channels only. Cloud contamination can be reduced to 0.2K by combining the spectral filter with a spatial coherence threshold, but the yield drops to 16,000 spectra per day. AIRS was launched in May 2002 on the Earth Observing System (EOS) Aqua satellite. Since September 2002 it has returned 4 million spectra of the globe each day.

  2. Surface Temperature variability from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Dang, V. T.; Aumann, H. H.

    2015-12-01

    To address the existence and possible causes of the climate hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014for the day and night conditions. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We compare the satellite data with the new surface data produced by Karl et al. (2015) who denies the reality of the climate hiatus. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The day-night difference is an indicator of the anthropogenic trend. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  3. The Evolution of Spaceborne Microwave Sounders for the U.S. Polar-Orbiting Weather Satellites

    NASA Technical Reports Server (NTRS)

    Shiue, James C.; Krimschansky, Sergey; Patel, Probodh; Hildebrand, Peter (Technical Monitor)

    2002-01-01

    The Advanced Technology Microwave Sounder (ATMS) is the next generation space-borne microwave sounder. It is the latest and most advanced version of a series of satellite-based microwave sounders, currently under development by NASA for the future U.S. operational polar-orbiting weather satellite system, called the NPOESS (National Polar-orbiting Operational Environment Satellite System), slated to begin orbiting around the end of this decade. This paper will present a brief history of the evolution of the space-borne microwave sounders, from its early-day scientific experiments, through the operational sounder aboard today's polar orbiting weather satellites, and ending in the ATMS development. It will also describe the evolution of microwave radiometer technology that enabled the space-borne microwave radiometry, from its early versions with simple, nadir-viewing, fixed-horn antennas to the present-day scanning reflector antennas with broad-band MMIC Low Noise Amplifiers, plus on-board calibrations.

  4. Dynamic real-time monitoring of chloroform in an indoor swimming pool air using open-path Fourier transform infrared spectroscopy.

    PubMed

    Chen, M-J; Duh, J-M; Shie, R-H; Weng, J-H; Hsu, H-T

    2016-06-01

    This study used open-path Fourier transform infrared (OP-FTIR) spectroscopy to continuously assess the variation in chloroform concentrations in the air of an indoor swimming pool. Variables affecting the concentrations of chloroform in air were also monitored. The results showed that chloroform concentrations in air varied significantly during the time of operation of the swimming pool and that there were two peaks in chloroform concentration during the time of operation of the pool. The highest concentration was at 17:30, which is coincident with the time with the highest number of swimmers in the pool in a day. The swimmer load was one of the most important factors influencing the chloroform concentration in the air. When the number of swimmers surpassed 40, the concentrations of chloroform were on average 4.4 times higher than the concentration measured without swimmers in the pool. According to the results of this study, we suggest that those who swim regularly should avoid times with highest number of swimmers, in order to decrease the risk of exposure to high concentrations of chloroform. It is also recommended that an automatic mechanical ventilation system is installed to increase the ventilation rate during times of high swimmer load. PMID:25916255

  5. Conditions for the use of infrared camera diagnostics in energy auditing of the objects exposed to open air space at isothermal sky

    NASA Astrophysics Data System (ADS)

    Kruczek, Tadeusz

    2015-03-01

    Convective and radiation heat transfer take place between various objects placed in open air space and their surroundings. These phenomena bring about heat losses from pipelines, building walls, roofs and other objects. One of the main tasks in energy auditing is the reduction of excessive heat losses. In the case of a low sky temperature, the radiation heat exchange is very intensive and the temperature of the top part of the horizontal pipelines or walls is lower than the temperature of their bottom parts. Quite often this temperature is also lower than the temperature of the surrounding atmospheric air. In the case of overhead heat pipelines placed in open air space, it is the ground and sky that constitute the surroundings. The aforementioned elements of surroundings usually have different values of temperature. Thus, these circumstances bring about difficulties during infrared inspections because only one ambient temperature which represents radiation of all surrounding elements must be known during the thermovision measurements. This work is aimed at the development of a method for determination of an equivalent ambient temperature representing the thermal radiation of the surrounding elements of the object under consideration placed in open air space, which could be applied at a fairly uniform temperature of the sky during the thermovision measurements as well as for the calculation of radiative heat losses.

  6. Workplace and environmental air contaminant concentrations measured by open path Fourier transform infrared spectroscopy: a statistical process control technique to detect changes from normal operating conditions.

    PubMed

    Malachowski, M S; Levine, S P; Herrin, G; Spear, R C; Yost, M; Yi, Z

    1994-05-01

    Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions. Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control. PMID:8012765

  7. Apperception of Clouds in AIRS Data

    NASA Technical Reports Server (NTRS)

    Huang, Hung-Lung; Smith, William L.

    2005-01-01

    Our capacity to simulate the radiative characteristics of the Earth system has advanced greatly over the past decade. However, new space based measurements show that idealized simulations might not adequately represent the complexity of nature. For example, AIRS simulated multi-layer cloud clearing research provides an excellent groundwork for early Atmospheric Infra-Red Sounder (AIRS) operational cloud clearing and atmospheric profile retrieval. However, it doesn't reflect the complicated reality of clouds over land and coastal areas. Thus far, operational AIRS/AMSU (Advanced Microwave Sounding Unit) cloud clearing is not only of low yield but also of unsatisfying quality. This is not an argument for avoiding this challenging task, rather a powerful argument for exploring other synergistic approaches, and for adapting these strategies toward improving both indirect and direct use of cloudy infrared sounding data. Ample evidence is shown in this paper that the indirect use of cloudy sounding data by way of cloud clearing is sub-optimal for data assimilation. Improvements are needed in quality control, retrieval yield, and overall cloud clearing retrieval performance. For example, cloud clearing over land, especially over the desert surface, has led to much degraded retrieval quality and often a very low yield of quality controlled cloud cleared radiances. If these indirect cloud cleared radiances are instead to be directly assimilated into NWP models, great caution must be used. Our limited and preliminary cloud clearing results from AIRS/AMSU (with the use of MODIS data) and an AIRS/MODIS synergistic approach have, however, shown that higher spatial resolution multispectral imagery data can provide much needed quality control of the AIRS/AMSU cloud clearing retrieval. When AIRS and Moderate Resolution Imaging Spectroradiometer (MODIS) are used synergistically, a higher spatial resolution over difficult terrain (especially desert areas) can be achieved and with a

  8. Accurate, practical simulation of satellite infrared radiometer spectral data

    SciTech Connect

    Sullivan, T.J.

    1982-09-01

    This study's purpose is to determine whether a relatively simple random band model formulation of atmospheric radiation transfer in the infrared region can provide valid simulations of narrow interval satellite-borne infrared sounder system data. Detailed ozonesondes provide the pertinent atmospheric information and sets of calibrated satellite measurements provide the validation. High resolution line-by-line model calculations are included to complete the evaluation.

  9. Nimbus-7 Stratospheric and Mesospheric Sounder (SAMS) experiment data user's guide

    NASA Technical Reports Server (NTRS)

    Taylor, F. W.; Rodgers, C. D.; Nutter, S. T.; Oslik, N.

    1989-01-01

    The Stratospheric and Mesospheric Sounder (SAMS) aboard Nimbus-7 observes infrared radiation from the atmospheric limb. Global upper atmosphere temperature profiles and vertical concentrations of H2O, NO, N2O, CH4 and CO2 are derived from these measurements. The status of all channels was carefully monitored. Temperature and composition were retrieved from the measurements by linearizing the direct equation about an a priori profile and using an optimum statistical estimator to find the most likely solution. The derived temperature and composition profiles are archived on two tape products whose file structure and record formats are described in detail. The gridded retrieved temperature tape (GRID-T) contains daily day and night average temperatures at 62 pressure levels in a 2.5 degree latitude by 10 degree longitude grid extending from 67.5 degrees N to 50 degrees S. The zonal mean methane and nitrous oxide composition tape (ZMT-G) contains zonal mean day and night average CH4 and N2O mixing ratios at 31 pressure levels for 2.5 degrees latitude zones extending from 67.5 degrees N to 50 degrees S.

  10. AIRS Impact on the Analysis and Forecast Track of Tropical Cyclone Nargis in a Global Data Assimilation and Forecasting System

    NASA Technical Reports Server (NTRS)

    Reale, O.; Lau, W.K.; Susskind, J.; Brin, E.; Liu, E.; Riishojgaard, L. P.; Rosenburg, R.; Fuentes, M.

    2009-01-01

    Tropical cyclones in the northern Indian Ocean pose serious challenges to operational weather forecasting systems, partly due to their shorter lifespan and more erratic track, compared to those in the Atlantic and the Pacific. Moreover, the automated analyses of cyclones over the northern Indian Ocean, produced by operational global data assimilation systems (DASs), are generally of inferior quality than in other basins. In this work it is shown that the assimilation of Atmospheric Infrared Sounder (AIRS) temperature retrievals under partial cloudy conditions can significantly impact the representation of the cyclone Nargis (which caused devastating loss of life in Myanmar in May 2008) in a global DAS. Forecasts produced from these improved analyses by a global model produce substantially smaller track errors. The impact of the assimilation of clear-sky radiances on the same DAS and forecasting system is positive, but smaller than the one obtained by ingestion of AIRS retrievals, possibly due to poorer coverage.

  11. Thermal infrared nadir observations of 24 atmospheric gases

    NASA Astrophysics Data System (ADS)

    Clarisse, Lieven; R'Honi, Yasmina; Coheur, Pierre-François; Hurtmans, Daniel; Clerbaux, Cathy

    2011-05-01

    Thermal infrared nadir sounders are ideal for observing total columns or vertical profiles of atmospheric gases such as water, carbon dioxide and ozone. High resolution sounders with a spectral resolution below 5 cm-1 can distinguish fine spectral features of trace gases. Forty years after the launch of the first hyperspectral sounder IRIS, we have now several state of the art instruments in orbit, with improved instrumental specifications. In this letter we give an overview of the trace gases which have been observed by infrared nadir sounders, focusing on new observations of the Infrared Atmospheric Sounding Interferometer (IASI). We present typical observations of 14 rare reactive trace gas species. Several species are reported here for the first time in nadir view, including nitrous acid, furan, acetylene, propylene, acetic acid, formaldehyde and hydrogen cyanide, observations which were made in a pyrocumulus cloud from the Australian bush fires of February 2009. Being able to observe this large number of reactive trace gases will likely improve our knowledge of source emissions and their impact on the environment and climate.

  12. GeoSTAR: a geostationary microwave sounder for the future

    NASA Astrophysics Data System (ADS)

    Lambrigtsen, B. H.; Brown, S. T.; Dinardo, S. J.; Gaier, T. C.; Kangaslahti, P. P.; Tanner, A. B.

    2007-09-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new Earth remote sensing instrument concept that has been under development at the Jet Propulsion Laboratory. First conceived in 1998 as a NASA New Millennium Program mission and subsequently developed in 2003-2006 as a proof-of-concept prototype under the NASA Instrument Incubator Program, it is intended to fill a serious gap in our Earth remote sensing capabilities - namely the lack of a microwave atmospheric sounder in geostationary orbit. The importance of such observations have been recognized by the National Academy of Sciences National Research Council, which recently released its report on a "Decadal Survey" of NASA Earth Science activities. One of the recommended missions for the next decade is a geostationary microwave sounder. GeoSTAR is well positioned to meet the requirements of such a mission, and because of the substantial investment NASA has already made in GeoSTAR technology development, this concept is fast approaching the necessary maturity for implementation in the next decade. NOAA is also keenly interested in GeoSTAR as a potential payload on its next series of geostationary weather satellites, the GOES-R series. GeoSTAR, with its ability to map out the three-dimensional structure of temperature, water vapor, clouds, precipitation and convective parameters on a continual basis, will significantly enhance our ability to observe hurricanes and other severe storms. In addition, with performance matching that of current and next generation of low-earth-orbiting microwave sounders, GeoSTAR will also provide observations important to the study of the hydrologic cycle, atmospheric processes and climate variability and trends. In particular, with GeoSTAR it will be possible to fully resolve the diurnal cycle. We discuss the GeoSTAR concept and basic design, the performance of the prototype, and a number of science applications that will be possible with GeoSTAR. The work reported

  13. Geo-STAR: A Geostationary Microwave Sounder for the Future

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn H.; Brown, S. T.; Dinardo, S. J.; Gaier, T. C.; Kangaslahti, P. P.; Tanner, A. B.

    2007-01-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a new Earth remote sensing instrument concept that has been under development at the Jet Propulsion Laboratory. First conceived in 1998 as a NASA New Millennium Program mission and subsequently developed in 2003-2006 as a proof-of-concept prototype under the NASA Instrument Incubator Program, it is intended to fill a serious gap in our Earth remote sensing capabilities - namely the lack of a microwave atmospheric sounder in geostationary orbit. The importance of such observations have been recognized by the National Academy of Sciences National Research Council, which recently released its report on a 'Decadal Survey' of NASA Earth Science activities1. One of the recommended missions for the next decade is a geostationary microwave sounder. GeoSTAR is well positioned to meet the requirements of such a mission, and because of the substantial investment NASA has already made in GeoSTAR technology development, this concept is fast approaching the necessary maturity for implementation in the next decade. NOAA is also keenly interested in GeoSTAR as a potential payload on its next series of geostationary weather satellites, the GOES-R series. GeoSTAR, with its ability to map out the three-dimensional structure of temperature, water vapor, clouds, precipitation and convective parameters on a continual basis, will significantly enhance our ability to observe hurricanes and other severe storms. In addition, with performance matching that of current and next generation of low-earth-orbiting microwave sounders, GeoSTAR will also provide observations important to the study of the hydrologic cycle, atmospheric processes and climate variability and trends. In particular, with GeoSTAR it will be possible to fully resolve the diurnal cycle. We discuss the GeoSTAR concept and basic design, the performance of the prototype, and a number of science applications that will be possible with GeoSTAR. The work reported

  14. Using Open and Interoperable Ways to Publish and Access LANCE AIRS Near-Real Time Data

    NASA Astrophysics Data System (ADS)

    Zhao, P.; Lynnes, C.; Vollmer, B.; Savtchenko, A. K.; Yang, W.

    2011-12-01

    Atmospheric Infrared Sounder (AIRS) Near-Real Time (NRT) data from the Land Atmosphere Near real time Capability for EOS (LANCE) provide the information on the global and regional atmospheric state with very low latency. An open and interoperable platform is useful to facilitate access to and integration of LANCE AIRS NRT data. This paper discusses the use of open-source software components to build Web services for publishing and accessing AIRS NRT data in the context of Service Oriented Architecture (SOA). The AIRS NRT data have also been made available through an OPeNDAP server. OPeNDAP allows several open-source netCDF-based tools such as Integrated Data Viewer, Ferret and Panoply to directly display the Level 2 data over the network. To enable users to locate swath data files in the OPeNDAP server that lie within a certain geographical area, graphical "granule maps" are being added to show the outline of each file on a map of the Earth. The metadata of AIRS NRT data and services is then explored to implement information advertisement and discovery in catalogue systems. Datacasting, an RSS-based technology for accessing Earth Science data and information to facilitate the subscriptions to AIRS NRT data availability, filtering, downloading and viewing data, is also discussed. To provide an easy entry point to AIRS NRT data and services, a Web portal designed for customized data downloading and visualization is introduced.

  15. Validation of AIRS Cloud Cleared Radiances Using MODIS and its Affect on QualityControl

    NASA Astrophysics Data System (ADS)

    Wilson, R. C.; Schreier, M. M.

    2015-12-01

    The Atmospheric Infrared Sounder (AIRS) was launched aboard the AQUA satellite to provide measurements of temperature, humidity, and various trace gases in support of climate research and weather prediction. Only clear sky measurements of the outgoing radiance are used in the AIRS physical retrieval of temperature, water vapor, and certain trace gases. To overcome cloud contamination the clear sky radiance is estimated using an iterative procedure that combines an initial estimate of the clear state from a neural network along with a three by three grid of AIRS measurements. The radiance error estimate, a component critical to the AIRS physical retrieval, must include contributions from all assumed parameters input to the forward model on top of instrument noise and amplification from cloud clearing. When the error estimate is too large the AIRS physical retrieval becomes over-constrained to the first guess profile. Therefore quantifying the cloud cleared error estimate is essential to an effective physical retrieval. We will validate the cloud-cleared radiances through the use of nearby clear ocean scenes and with comparisons to clear pixels from the Moderate Resolution Imaging Spectro-radiometer (MODIS). AIRS cloud cleared radiances are spectrally convolved to MODIS channels for this comparison. This analysis quantifies error due to cloud-clearing and demonstrates that clear MODIS pixels can be used with the standard AIRS quality control procedure to improve identification poor retrievals.

  16. Assessing the Potential of the AIRS Retrieved Surface Temperature for 6-Hour Average Temperature Forecast in River Forecast Centers

    NASA Astrophysics Data System (ADS)

    Ding, F.; Theobald, M.; Vollmer, B.; Savtchenko, A. K.; Hearty, T. J.; Esfandiari, A. E.

    2012-12-01

    Producing timely and accurate water forecast and information is the mission of National Weather Service River Forecast Centers (NWS RFCs) of National Oceanic and Atmospheric Administration (NOAA). The river forecast system in RFCs requires average surface temperature in the fixed 6-hour period 000-0600, 0600-1200, 1200-1800, and 1200-0000 UTC. The current logic of RFC temperature forecast relies on ingest of point values of daytime maximum and nighttime minimum temperature. Meanwhile, the mean temperature for the 6-hour period is estimated from a weighted average of daytime maximum and nighttime minimum temperature. The Atmospheric Infrared Sounder (AIRS) in the first high spectral resolution infrared sounder on board the Aqua satellite which was launched in May 2002 and follows a Sun-synchronous polar orbit. It is aimed to produce high resolution atmospheric profile and surface atmospheric parameters. As Aqua crosses the equator at about 1330 and 0130 local time, the AIRS retrieved surface temperature may represent daytime maximum and nighttime minimum value. Comparing to point observation from surface weather stations which are often sparse over the less-populated area and are unevenly distributed, satellite may obtain better area averaged observation. This test study assesses the potential of using AIRS retrieved surface temperature to forecast 6-hour average temperature for NWS RFCs. The California Nevada RFC is selected due to the poor coverage of surface observation in the mountainous region and spring snow melting. The study focuses on the March to May spring season when water from snowpack melting often plays important role in flood. AIRS retrieved temperature and surface weather station data set will be used to derive statistical weighting coefficient for 6-hour average temperature forecast. The resulting forecast biases and errors will be the main indicators of the potential usage. All study results will be presented in the meeting.

  17. No widespread dust in the upper atmosphere of Mars from Mars Climate Sounder observations

    NASA Astrophysics Data System (ADS)

    Kleinboehl, Armin; Schofield, John T.; Kass, David M.; Abdou, Wedad A.; McCleese, Daniel J.

    2015-04-01

    The vertical distribution of dust in the Martian atmosphere has been a topic of discussion in the recent years. Measurements by limb sounding instruments like the Mars Climate Sounder (MCS) and the Thermal Emission Spectrometer (TES) indicate that atmospheric dust is not homogeneously distributed in the vertical but exhibits layering in the lower atmosphere. Recent retrievals from TES measurements also suggest a dust maximum higher in the atmosphere that predominantly occurs at 50-60 km altitude on the daytime hemisphere. We use new retrievals from MCS measurements to investigate this deduction. MCS is a mid- and far-infrared thermal emission radiometer on board the Mars Reconnaissance Orbiter. It measures radiances in limb and on-planet viewing geometries. From these radiance measurements, profiles of atmospheric temperature, dust and water ice are retrieved from the surface to ~80 km with a vertical resolution of ~5 km. Updates to the retrieval algorithm yield improved representations of aerosols above ~40 km altitude. With a few notable exceptions, retrieved dust extinctions in the upper atmosphere do not exceed 1e-5 km-1 at mid-infrared wavelengths, which is close to the limit of the MCS sensitivity. The sensitivity of an MCS limb measurement to aerosols at these altitudes is typically not limited by signal-to-noise but rather by the uncertainties in the representation of the instrument's vertical field-of-view, the far wings of which can provide radiance contributions from the lower atmosphere and the surface. Sensitivity studies suggest that low radiances measured at high altitudes are not caused by widespread dust but can be explained by these radiance contributions. Thus MCS measurements do not support the existence of widespread dust in the upper atmosphere of Mars.

  18. Validation of nitrogen dioxide measurements from the Improved Stratospheric and Mesospheric Sounder

    NASA Astrophysics Data System (ADS)

    Reburn, W. J.; Remedios, J. J.; Morris, P. E.; Rodgers, C. D.; Taylor, F. W.; Kerridge, B. J.; Knight, R. J.; Ballard, J.; Kumer, J. B.; Massie, S. T.

    1996-04-01

    Measurements of nitrogen dioxide (NO2) from the Improved Stratospheric and Mesospheric Sounder (ISAMS) on the Upper Atmosphere Research Satellite (UARS) are assessed. Channel 5 of the instrument was dedicated to observations of nitrogen dioxide and employed pressure-modulation and wideband radiometry to make measurements at 6.2 μm. This dual technique allows simultaneous determination of nitrogen dioxide mixing ratio and the aerosol extinction coefficient at this wavelength and therefore provides nitrogen dioxide data even in the presence of heavy aerosol loading. Approximately 180 days of data, in the period from September 1991 to July 1992, were obtained with, typically, over 2600 profiles per day for each retrieved species, covering an altitude range of 100-0.01 mbar. In this paper the version 10 data are assessed and a full error analysis is described. Comparisons with the Cryogenic Limb Array Etalon Spectrometer (CLAES) on UARS and the Limb Infrared Monitor of the Stratosphere (LIMS) on Nimbus 7 are also presented. It is concluded that the morphology of the retrieved ISAMS fields is robust and consistent with concurrent as well as previous infrared satellite measurements. Random errors are estimated to be of the order of 10% for nighttime and 15% for daytime NO2 near the maxima of the distributions, and systematic errors are estimated to be of a similar size. However, there remains an unresolved systematic difference of about a factor of 2 between ISAMS and CLAES. Both random and systematic errors are likely to be reduced in future versions of the processing.

  19. A submillimeter sounder for the Titan Saturn System Mission (TSSM)

    NASA Astrophysics Data System (ADS)

    Lellouch, E.; Vinatier, S.; Moreno, R.; Allen, M.; Gulkis, S.; Hartogh, P.; Mehdi, I.; Maestrini, A.; Krieg, J.-M.

    2008-09-01

    A submillimeter sounder (SMS) onboard the TSSM mission and operating mostly in limb viewing is a powerful instrument to study Titan's atmosphere from ~50 to 1200 km, and especially the largely unexplored "agnostophere" from 500 to 1000 km. Unique capabilities of such an instrument include (i) measurement of temperature field up to 1200 km, using rotational lines of CH4, CO, and HCN (ii) direct, absolute and accurate wind measurements from Doppler shifts (iii) high sensitivity to trace minor compounds, particularly nitriles and rare isotope species. Altogether, SMS can provide a new characterization of the couplings between stratospheric/mesospheric chemistry and dynamics, and of their relationships with the complex thermospheric chemistry observed by Cassini. At Enceladus, SMS can provide detailed measurements of temperature, composition and gas plume dynamics.

  20. Stratospheric CH3CN from the UARS Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Livesey, Nathaniel J.; Waters, Joe W.; Khosravi, Rashid; Brasseur, Guy P.; Tyndall, Geoffrey S.; Read, William G.

    CH3CN in the stratosphere has been measured by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS), providing the first global CH3CN dataset. The MLS observations are in broad agreement with past high and midlatitude observations of CH3CN, although concentrations are a little larger than previously observed. In the tropics, where CH3CN has not up to now been measured, a persistent ‘peak’ in the profiles is seen around 22 hPa, which may be evidence of a tropical stratospheric CH3CN source. Comparisons are made with the NCAR SOCRATES model, including runs having an artificial tropical stratospheric CH3CN source.

  1. Development and application of an optical sensor for ethene in ambient air using near infra-red cavity ring down spectroscopy and sample preconcentration.

    PubMed

    Aziz, M S I; Orr-Ewing, Andrew J

    2012-12-01

    An automated near infra-red (IR) continuous wave cavity ring down spectrometer with sample preconcentration has been developed for the measurement of ethene (C₂H₄) in air. The spectrometer incorporated a distributed feedback diode laser operating at wavelengths λ∼ 1.6 μm and a pre-concentration system containing an adsorbent, molecular sieve 4A (MS4A). An absorption line located at 6148.58 cm⁻¹, and free from spectral overlap with other atmospheric molecules, was used for ethene detection. The spectrometer has a capacity for determination of atmospheric ethene mixing ratios at half hour time intervals, with a detection limit (2 SD above baseline noise) of 280 ppt. Both weekday and weekend measurements were performed in ambient air for periods of up to 30 hours. Average daytime mixing ratios of ethene were observed to be 2 ppbv and 1 ppbv during weekdays and weekends respectively. The mixing ratios of ethene varied from 0.6 ppbv to 1.2 ppbv in Bristol air during the weekend, with influence of meteorological conditions. The observed variations are discussed with consideration of probable sources and various meteorological parameters. A correlation is observed in the mixing ratio of ethene and nitrogen dioxide. PMID:23132283

  2. Lidar measurements of the column CO2 mixing ratio made by NASA Goddard's CO2 Sounder during the NASA ASCENDS 2014 Airborne campaign.

    NASA Astrophysics Data System (ADS)

    Ramanathan, A. K.; Mao, J.; Abshire, J. B.; Kawa, S. R.

    2015-12-01

    Remote sensing measurements of CO2 from space can help improve our understanding of the carbon cycle and help constrain the global carbon budget. However, such measurements need to be sufficiently accurate to detect small (1 ppm) changes in the CO2 mixing ratio (XCO2) against a large background (~ 400 ppm). Satellite measurements of XCO2 using passive spectrometers, such as those from the Japanese GOSAT (Greenhouse gas Observing Satellite) and the NASA OCO-2 (Orbiting Carbon Observatory-2) are limited to daytime sunlit portions of the Earth and are susceptible to biases from clouds and aerosols. For this reason, NASA commissioned the formulation study of ASCENDS a space-based lidar mission. NASA Goddard Space Flight Center's CO2 Sounder lidar is one candidate approach for the ASCENDS mission. The NASA GSFC CO2 Sounder measures the CO2 mixing ratio using a pulsed multi-wavelength integrated path differential absorption (IPDA) approach. The CO2 Sounder has flown in the 2011, 2013 and 2014 ASCENDS airborne campaigns over the continental US, and has produced measurements in close agreement with in situ measurements of the CO2 column. In 2014, the CO2 Sounder upgraded its laser with a precision step-locked diode laser source to improve the lidar wavelength position accuracy. It also improved its optical receiver with a low-noise, high efficiency, HgCdTe avalanche photo diode detector. The combination of these two technologies enabled lidar XCO2 measurements with unprecedented accuracy. In this presentation, we show analysis from the ASCENDS 2014 field campaign, exploring: (1) Horizontal XCO2 gradients measured by the lidar, (2) Comparisons of lidar XCO2 measurements against the Parameterized Chemistry Transport Model (PCTM), and (3) Lidar column water vapor measurements using a HDO absorption line that occurs next to the CO2 absorption line. This can reduce the uncertainty in the dry air column used in XCO2 retrievals.

  3. Use of INSAT-3D sounder and imager radiances in the 4D-VAR data assimilation system and its implications in the analyses and forecasts

    NASA Astrophysics Data System (ADS)

    Indira Rani, S.; Taylor, Ruth; George, John P.; Rajagopal, E. N.

    2016-05-01

    INSAT-3D, the first Indian geostationary satellite with sounding capability, provides valuable information over India and the surrounding oceanic regions which are pivotal to Numerical Weather Prediction. In collaboration with UK Met Office, NCMRWF developed the assimilation capability of INSAT-3D Clear Sky Brightness Temperature (CSBT), both from the sounder and imager, in the 4D-Var assimilation system being used at NCMRWF. Out of the 18 sounder channels, radiances from 9 channels are selected for assimilation depending on relevance of the information in each channel. The first three high peaking channels, the CO2 absorption channels and the three water vapor channels (channel no. 10, 11, and 12) are assimilated both over land and Ocean, whereas the window channels (channel no. 6, 7, and 8) are assimilated only over the Ocean. Measured satellite radiances are compared with that from short range forecasts to monitor the data quality. This is based on the assumption that the observed satellite radiances are free from calibration errors and the short range forecast provided by NWP model is free from systematic errors. Innovations (Observation - Forecast) before and after the bias correction are indicative of how well the bias correction works. Since the biases vary with air-masses, time, scan angle and also due to instrument degradation, an accurate bias correction algorithm for the assimilation of INSAT-3D sounder radiance is important. This paper discusses the bias correction methods and other quality controls used for the selected INSAT-3D sounder channels and the impact of bias corrected radiance in the data assimilation system particularly over India and surrounding oceanic regions.

  4. Intercomparison of three microwave/infrared high resolution line-by-line radiative transfer codes

    NASA Astrophysics Data System (ADS)

    Schreier, F.; Garcia, S. Gimeno; Milz, M.; Kottayil, A.; Höpfner, M.; von Clarmann, T.; Stiller, G.

    2013-05-01

    An intercomparison of three line-by-line (lbl) codes developed independently for atmospheric sounding - ARTS, GARLIC, and KOPRA - has been performed for a thermal infrared nadir sounding application assuming a HIRS-like (High resolution Infrared Radiation Sounder) setup. Radiances for the HIRS infrared channels and a set of 42 atmospheric profiles from the "Garand dataset" have been computed. Results of this intercomparison and a discussion of reasons of the observed differences are presented.

  5. Source fingerprint monitoring of air pollutants from petrochemical industry and the determination of their annual emission flux using open path Fourier transform infrared spectroscopy

    SciTech Connect

    Yih-Shiaw Huang; Shih-Yi Chang; Tai-Ly Tso

    1996-12-31

    Toxic air pollutants were investigated in several petrochemical industrial park in Taiwan using a movable open-path Fourier-transform infrared spectroscopy (FTIR). The results show the qualitative and quantitative analysis of emission gases from plants, and also provide the emission rates of various compounds. More than twenty compounds under usual operation were found from these industrial park. The concentration variation with time could be correlated exactly with the distances from the emission source along the wind direction. This means that by changing the measuring points the source of emission could be unambiguously identified. The point, area and line source (PAL) plume dispersion model has been applied to estimate the emission rate of either a point or an area source. The local atmospheric stability was determined by releasing an SF{sub 6} tracer. The origin of errors came mainly from the uncertainty of the source configuration and the variation of the meteorological condition. Through continuous measurement using a portable open-path Fourier transform infrared (POP-FTIR) spectrometer, the maximum value of the emission rate and the annual amount of emission could be derived. The emission rate of the measured toxic gases was derived by the model technique, and the results show that the emission amount is on the order of ten to hundred tons per year.

  6. Direct measurements of HONO and NO2 by tunable infrared differential absorption spectroscopy; Results from two field campaigns sampling aircraft exhaust and ambient urban air

    NASA Astrophysics Data System (ADS)

    Lee, B. H.; Santoni, G.; Herndon, S. C.; Wood, E. C.; Miake-Lye, R. C.; Munger, J. W.; Wofsy, S. C.; Zahniser, M. S.; McManus, J. B.; Nelson, D. D.

    2009-12-01

    Nitrous acid (HONO) is an important source of hydroxyl radicals (OH), the main oxidizing agent in the atmosphere. However, gaseous HONO has historically proven difficult to measure accurately and to date there is no standard technique. We describe a new instrument capable of high-frequency measurements of HONO and nitrogen dioxide (NO2) mixing ratios by tunable infrared differential absorption spectrometry. Mid-infrared light from two continuous-wave mode quantum cascade lasers traverse a 210 m path through a multi-pass astigmatic cell at reduced pressures for the direct detection of HONO (1660 cm-1) and NO2 (1604 cm-1). We achieve an absorbance precision less than 3×10-6 Hz-1 in one second, which translates to detection limits (S/N=3) of 300 and 30 ppt for HONO and NO2, respectively, in one second. Both lasers and the detector are thermoelectrically cooled, facilitating long-term unattended measurements. We also report preliminary results from two field campaigns; the Alternative Aviation Fuels Experiment (AAFEX) and the Study of Houston Air Radical Precursors (SHARP). At AAFEX, HONO emission ratios relative to CO2 and NOy observed in commercial aircraft exhaust are larger than in most other combustion sources and likely to play a significant role in regional HOx chemistry. Preliminary analysis from the SHARP campaign shows good agreement in HONO and NO2 levels between various measurement techniques.

  7. Low level water vapor fields from the VISSR Atmospheric Sounder (VAS) 'split window' channels

    NASA Technical Reports Server (NTRS)

    Robinson, W. D.; Chesters, D.; Uccellini, L. W.

    1983-01-01

    The use of the 11 and 12-micron IR-radiometer channels of the VISSR Atmosphere Sounder (VAS) on the GOES to detect water vapor in the lowest 300-400 mb of the troposphere is reported. An algorithm is developed to eliminate the background temperature, allowing the calculation of precipitable water (PW) over both land and water via a single-layer radiative model. This 'split-window' method is demonstrated in a case study, covering the US on July 13, 1981. PW values were calculated from five VAS images and compared with those from radiosonde data and surface measurements. It is shown that the VAS PW images have good resolution (15 km), reveal vivid, continuously evolving details, and differentiate deep, convection-supporting layers from shallow ones. PW ranged from 1.7 to 5.5 g/sq cm (+ or - 1.0 g/sq cm), in good agreement with other measurements. Since this method can detect mesoscale water-vapor fields in relatively clear air, it is considered of great potential value for numerical forecasting.

  8. Microwave Limb Sounder/El Nino Watch - Water Vapor Measurement, October, 1997

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image shows atmospheric water vapor in Earth's upper troposphere, about 10 kilometers (6 miles) above the surface, as measured by the Microwave Limb Sounder (MLS) instrument flying aboard the Upper Atmosphere Research Satellite. These data collected in early October 1997 indicate the presence of El Nino by showing a shift of humidity from west to east (blue and red areas) along the equatorial Pacific Ocean. El Nino is the term used when the warmest equatorial Pacific Ocean water is displaced toward the east. The areas of high atmospheric moisture correspond to areas of very warm ocean water. Warmer water evaporates at a higher rate and the resulting warm moist air then rises, forming tall cloud towers. In the tropics, the warm water and the resulting tall cloud towers typically produce large amounts of rain. The MLS instrument, developed at NASA's Jet Propulsion Laboratory, measures humidity at the top of these clouds, which are very moist. This rain is now occurring in the eastern Pacific Ocean and has left Indonesia (deep blue region) unusually dry, resulting in the current drought in that region. This image also shows moisture moving north into Mexico, an effect of several hurricanes spawned by the warm waters of El Nino.

  9. MJO-related intraseasonal variation of gravity waves in the Southern Hemisphere tropical stratosphere revealed by high-resolution AIRS observations

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Chikara; Sato, Kaoru; Alexander, M. Joan; Hoffmann, Lars

    2016-07-01

    The intraseasonal variability of gravity waves (GWs) in the austral summer middle stratosphere was examined using dedicated high-resolution temperature retrieval from the Atmospheric Infrared Sounder data. Composite maps were made of stratospheric GW temperature variances, large-scale zonal winds around the tropopause, and precipitation based on the real-time multivariate Madden-Julian Oscillation (MJO) index. Regional distributions of these quantities are synchronized with the MJO: The GW variances are larger for stronger precipitation and for more strongly westward wind around the tropopause at a given precipitation. These results suggest that the GWs observed by Atmospheric Infrared Sounder (AIRS) in the stratosphere originate from convection. Moreover, it is shown that the zonal wind around the tropopause likely controls the GW propagation into the stratosphere by a critical level filtering mechanism and/or the GW generation by an obstacle source effect. This means that the MJO can modulate the middle atmospheric circulation by regulating the GWs in two ways, namely, generation and propagation.

  10. Satellite observation of atmospheric methane: intercomparison between AIRS and GOSAT TANSO-FTS retrievals

    NASA Astrophysics Data System (ADS)

    Zou, M.; Xiong, X.; Saitoh, N.; Warner, J.; Zhang, Y.; Chen, L.; Weng, F.

    2015-10-01

    Space-borne observations of atmospheric methane (CH4) have been made using the Atmospheric Infrared Sounder (AIRS) on the EOS/Aqua satellite since August 2002 and the Thermal and Near-infrared Sensor for Carbon Observation Fourier Transform Spectrometer (TANSO-FTS) on the Greenhouse Gases Observing Satellite (GOSAT) since April 2009. This study compared the GOSAT TANSO-FTS thermal infrared (TIR) version 1.0 CH4 product with the collocated AIRS version 6 CH4 product using data from 1 August 2010 to 30 June 2012, including the CH4 mixing ratios and the total column amounts. The results show that at 300-600 hPa, where both AIRS and GOSAT-TIR CH4 have peak sensitivities, they agree very well, but GOSAT-TIR retrievals tend to be higher than AIRS in layer 200-300 hPa. At 300 hPa the CH4 mixing ratio from GOSAT-TIR is, on average, 10.3 ± 31.8 ppbv higher than that from AIRS, and at 600 hPa GOSAT-TIR retrieved CH4 is -16.2 ± 25.7 ppbv lower than AIRS CH4. Comparison of the total column amount of CH4 shows that GOSAT-TIR agrees with AIRS to within 1 % in the mid-latitude regions of Southern Hemisphere and in tropics. In the mid to high latitudes in the Northern Hemisphere, GOSAT-TIR is ~ 1-2 % lower than AIRS, and in the high-latitude regions of Southern Hemisphere the difference of GOSAT from AIRS varies from -3 % in October to +2 % in July. The difference between AIRS and GOSAT TANSO-FTS retrievals is mainly due to the difference in retrieval algorithms and instruments itself, and the larger difference in the high latitude regions is associated with the low information content and small degree of freedoms of the retrieval. The degree of freedom of GOSAT-TIR retrievals is lower than that of AIRS also indicates that the constraint in GOSAT-TIR retrieval may be too strong. From the good correlation between AIRS and GOSAT-TIR retrievals and the seasonal variation they observed we are confident that the thermal infrared measurements from AIRS and GOSAT-TIR can provide

  11. Satellite observation of atmospheric methane: intercomparison between AIRS and GOSAT TANSO-FTS retrievals

    NASA Astrophysics Data System (ADS)

    Zou, Mingmin; Xiong, Xiaozhen; Saitoh, Naoko; Warner, Juying; Zhang, Ying; Chen, Liangfu; Weng, Fuzhong; Fan, Meng

    2016-08-01

    Space-borne observations of atmospheric methane (CH4) have been made using the Atmospheric Infrared Sounder (AIRS) on the EOS/Aqua satellite since August 2002 and the Thermal and Near-infrared Sensor for Carbon Observation Fourier Transform Spectrometer (TANSO-FTS) on the Greenhouse Gases Observing Satellite (GOSAT) since April 2009. This study compared the GOSAT TANSO-FTS thermal infrared (TIR) version 1.0 CH4 product with the collocated AIRS version 6 CH4 product using data from 1 August 2010 to 30 June 2012, including the CH4 mixing ratios and the total column amounts. The results show that at 300-600 hPa, where both AIRS and GOSAT-TIR CH4 have peak sensitivities, they agree very well, but GOSAT-TIR retrievals tend to be higher than AIRS in layer 200-300 hPa. At 300 hPa the CH4 mixing ratio from GOSAT-TIR is, on average, 10.3 ± 31.8 ppbv higher than that from AIRS, and at 600 hPa GOSAT-TIR retrieved CH4 is -16.2 ± 25.7 ppbv lower than AIRS CH4. Comparison of the total column amount of CH4 shows that GOSAT-TIR agrees with AIRS to within 1 % in the mid-latitude regions of the Southern Hemisphere and in the tropics. In the mid to high latitudes in the Northern Hemisphere, comparison shows that GOSAT-TIR is ˜ 1-2 % lower than AIRS, and in the high-latitude regions of the Southern Hemisphere the difference of GOSAT from AIRS varies from -3 % in October to +2 % in July. The difference between AIRS and GOSAT TANSO-FTS retrievals is mainly due to the difference in retrieval algorithms and instruments themselves, and the larger difference in the high-latitude regions is associated with the low information content and small degrees of freedom of the retrieval. The degrees of freedom of GOSAT-TIR retrievals are lower than that of AIRS, which also indicates that the constraint in GOSAT-TIR retrievals may be too strong. From the good correlation between AIRS and GOSAT-TIR retrievals and the seasonal variation they observed, we are confident that the thermal infrared

  12. Aura's Microwave Limb Sounder Estimates of Ozone Loss, 2004/2005 Arctic Winter

    NASA Technical Reports Server (NTRS)

    2005-01-01

    These data maps from Aura's Microwave Limb Sounder depict levels of hydrogen chloride (top), chlorine monoxide (center), and ozone (bottom) at an altitude of approximately 19 kilometers (490,000 feet) on selected days during the 2004-05 Arctic winter. White contours demark the boundary of the winter polar vortex.

    The maps from December 23, 2004, illustrate vortex conditions shortly before significant chemical ozone destruction began. By January 23, 2005, chlorine is substantially converted from the 'safe' form of hydrogen chloride, which is depleted throughout the vortex, to the 'unsafe' form of chlorine monoxide, which is enhanced in the portions of the region that receive sunlight at that time of year. Ozone increased over the month as a result of dynamical effects, and chemical ozone destruction is just beginning at this time. A brief period of intense cold a few days later promotes further chlorine activation and consequent changes in hydrogen chloride and chlorine monoxide levels on January 27, 2005. Peak chlorine monoxide enhancement occurs in early February.

    By February 24, 2005, chlorine deactivation is well underway, with chlorine monoxide abundances dropping and hydrogen chloride abundances rising. Almost all chlorine monoxide has been quenched by March 10, 2005. The fact that hydrogen chloride has not fully rebounded to December abundances suggests that some of that chemical was recovered into another chlorine reservoir species.

    Ozone maps for January 27, 2005, through March 10, 2005, show indications of mixing of air from outside the polar vortex into it. Such occurrences throughout this winter, especially in late February and early March, complicate analyses, and detailed calculations are required to rigorously disentangle chemical and dynamical effects and accurately diagnose chemical ozone destruction.

    Based on various analyses of Microwave Limb Sounder data, we estimate that maximum local ozone loss of approximately 2 parts

  13. Validation of AIRS V6 Surface Temperature over Greenland with GCN and NOAA Stations

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Hearty, Thomas; Cullather, Richard; Nowicki, Sophie; Susskind, Joel

    2016-01-01

    This work compares the temporal and spatial characteristics of the AIRSAMSU (Atmospheric Infrared Sounder Advanced Microwave Sounding Unit A) Version 6 and MODIS (Moderate resolution Imaging Spectroradiometer) Collection 5 derived surface temperatures over Greenland. To estimate uncertainties in space-based surface temperature measurements, we re-projected the MODIS Ice Surface Temperature (IST) to 0.5 by 0.5 degree spatial resolution. We also re-gridded AIRS Skin Temperature (Ts) into the same grid but classified with different cloud conditions and surface types. These co-located data sets make intercomparison between the two instruments relatively straightforward. Using this approach, the spatial comparison between the monthly mean AIRS Ts and MODIS IST is in good agreement with RMS 2K for May 2012. This approach also allows the detection of any long-term calibration drift and the careful examination of calibration consistency in the MODIS and AIRS temperature data record. The temporal correlations between temperature data are also compared with those from in-situ measurements from GC-Net (GCN) and NOAA stations. The coherent time series of surface temperature evident in the correlation between AIRS Ts and GCN temperatures suggest that at monthly time scales both observations capture the same climate signal over Greenland. It is also suggested that AIRS surface air temperature (Ta) can be used to estimate the boundary layer inversion.

  14. View-angle-dependent AIRS Cloudiness and Radiance Variance: Analysis and Interpretation

    NASA Technical Reports Server (NTRS)

    Gong, Jie; Wu, Dong L.

    2013-01-01

    Upper tropospheric clouds play an important role in the global energy budget and hydrological cycle. Significant view-angle asymmetry has been observed in upper-level tropical clouds derived from eight years of Atmospheric Infrared Sounder (AIRS) 15 um radiances. Here, we find that the asymmetry also exists in the extra-tropics. It is larger during day than that during night, more prominent near elevated terrain, and closely associated with deep convection and wind shear. The cloud radiance variance, a proxy for cloud inhomogeneity, has consistent characteristics of the asymmetry to those in the AIRS cloudiness. The leading causes of the view-dependent cloudiness asymmetry are the local time difference and small-scale organized cloud structures. The local time difference (1-1.5 hr) of upper-level (UL) clouds between two AIRS outermost views can create parts of the observed asymmetry. On the other hand, small-scale tilted and banded structures of the UL clouds can induce about half of the observed view-angle dependent differences in the AIRS cloud radiances and their variances. This estimate is inferred from analogous study using Microwave Humidity Sounder (MHS) radiances observed during the period of time when there were simultaneous measurements at two different view-angles from NOAA-18 and -19 satellites. The existence of tilted cloud structures and asymmetric 15 um and 6.7 um cloud radiances implies that cloud statistics would be view-angle dependent, and should be taken into account in radiative transfer calculations, measurement uncertainty evaluations and cloud climatology investigations. In addition, the momentum forcing in the upper troposphere from tilted clouds is also likely asymmetric, which can affect atmospheric circulation anisotropically.

  15. Detection of a tropospheric ozone anomaly using a newly developed ozone retrieval algorithm for an up-looking infrared interferometer

    NASA Astrophysics Data System (ADS)

    Lightner, K. J.; McMillan, W. W.; McCann, K. J.; Hoff, R. M.; Newchurch, M. J.; Hintsa, E. J.; Barnet, C. D.

    2009-03-01

    On 2 June 2003, the Baltimore Bomem Atmospheric Emitted Radiance Interferometer (BBAERI) recorded an infrared spectral time series indicating the presence of a tropospheric ozone anomaly. The measurements were collected during an Atmospheric Infrared Sounder (AIRS) validation campaign called the 2003 AIRS BBAERI Ocean Validation Experiment (ABOVE03) conducted at the United States Coast Guard Chesapeake Light station located 14 miles due east of Virginia Beach, Virginia (36.91°N, 75.71°W). Ozone retrievals were performed with the Kurt Lightner Ozone BBAERI Retrieval (KLOBBER) algorithm, which retrieves tropospheric column ozone, surface to 300 mbar, from zenith-viewing atmospheric thermal emission spectra. KLOBBER is modeled after the AIRS retrieval algorithm consisting of a synthetic statistical regression followed by a physical retrieval. The physical retrieval is implemented using the k-Compressed Atmospheric Radiative Transfer Algorithm (kCARTA) to compute spectra. The time series of retrieved integrated ozone column on 2 June 2003 displays spikes of about 10 Dobson units, well above the error of the KLOBBER algorithm. Using instrumentation at Chesapeake Light, satellite imaging, trace gas retrievals from satellites, and Potential Vorticity (PV) computations, it was determined that these sudden increases in column ozone likely were caused by a combination of midtropospheric biomass burning products from forest fires in Siberia, Russia, and stratospheric intrusion by a tropopause fold occurring over central Canada and the midwestern United States.

  16. Supercontinuum emission and enhanced self-guiding of infrared femtosecond filaments sustained by third-harmonic generation in air

    SciTech Connect

    Berge, L.; Mejean, G.; Kasparian, J.; Yu, J.; Frey, S.; Salmon, E.; Wolf, J.P.

    2005-01-01

    The long-range propagation of two-colored femtosecond filaments produced by an infrared (IR) ultrashort pulse exciting third harmonics (TH) in the atmosphere is investigated, both theoretically and experimentally. First, it is shown that the coupling between the pump and TH components is responsible for a wide spectral broadening, extending from ultraviolet (UV) wavelengths (220 nm) to the mid-IR (4.5 {mu}m). Supercontinuum generation takes place continuously as the laser beam propagates, while TH emission occurs with a conversion efficiency as high as 0.5%. Second, the TH pulse is proven to stabilize the IR filament like a saturable quintic nonlinearity through four-wave mixing and cross-phase modulation. Third, the filamentation is accompanied by a conical emission of the beam, which becomes enlarged at UV wavelengths. These properties are revealed by numerical simulations and direct experimental observations performed from the Teramobile laser facility.

  17. Progress in developing GeoSTAR - Microwave Sounder for GOES-R

    NASA Technical Reports Server (NTRS)

    Lambrigtsen, Bjorn H.; Brown, S. T.; Dinardo, S. J.; Kangaslahti, P. P.; Tanner, A. B.; Wilson, W. J.

    2005-01-01

    The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR)is a new concept for a microwave sounder, intended to be deployed at the Jet Propulsion Laboratory under NASA Instrument Incubator Program sponsorship, and is currently undergoing tests and performance characterization.

  18. Data Assimilation of AIRS Water Vapor Profiles: Impact on Precipitation Forecasts for Atmospheric River Cases Affecting the Western of the United States

    NASA Technical Reports Server (NTRS)

    Blankenship, Clay; Zavodsky, Bradley; Jedlovec, Gary; Wick, Gary; Neiman, Paul

    2013-01-01

    Atmospheric rivers are transient, narrow regions in the atmosphere responsible for the transport of large amounts of water vapor. These phenomena can have a large impact on precipitation. In particular, they can be responsible for intense rain events on the western coast of North America during the winter season. This paper focuses on attempts to improve forecasts of heavy precipitation events in the Western US due to atmospheric rivers. Profiles of water vapor derived from from Atmospheric Infrared Sounder (AIRS) observations are combined with GFS forecasts by a three-dimensional variational data assimilation in the Gridpoint Statistical Interpolation (GSI). Weather Research and Forecasting (WRF) forecasts initialized from the combined field are compared to forecasts initialized from the GFS forecast only for 3 test cases in the winter of 2011. Results will be presented showing the impact of the AIRS profile data on water vapor and temperature fields, and on the resultant precipitation forecasts.

  19. AIRS First Light Data: Typhoon Ramasun, July 3, 2002

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2Figure 3

    Four images of Tropical Cyclone Ramasun were obtained July 3, 2002 by the Atmospheric Infrared Sounder experiment system onboard NASA's Aqua spacecraft. The AIRS experiment, with its wide spectral coverage in four diverse bands, provides the ability to obtain complete 3-D observations of severe weather, from the surface, through clouds to the top of the atmosphere with unprecedented accuracy. This accuracy is the key to understanding weather patterns and improving weather predictions.

    Viewed separately, none of these images can provide accurate 3-D descriptions of the state of the atmosphere because of interference from clouds. However, the ability to make simultaneous observations at a wide range of wavelengths allows the AIRS experiment to 'see' through clouds.

    This visible light picture from the AIRS instrument provides important information about the location of the cyclone, cloud structure and distribution.

    The AIRS instrument image at 900 cm-1 (Figure 1) is from a 10 micron transparent 'window channel' that is little affected by water vapor but still cannot see through clouds. In clear areas (like the eye of the cyclone and over northwest Australia) it measures a surface temperature of about 300K (color encoded red). In cloudy areas it measures the cloud top temperature, about 200K for the cyclone, which translates to a cloud top height of about 50,000 feet.

    On the other hand, most clouds are relatively transparent in microwave, and the Advanced Microwave Sounding Instrument channel image (Figure 2) can see through all but the densest clouds. For example, Taiwan, which is covered by clouds, is clearly visible.

    The Humidity Sounder for Brazil instrument channel (Figure 3), also in the microwave, is more sensitive to both clouds and humidity. Only in clear, dry regions, such as the eye of the cyclone or the

  20. Operational use of the AIRS Total Column Ozone Retrievals along with the RGB Airmass Product as Part of the GOES-R Proving Ground

    NASA Technical Reports Server (NTRS)

    Folmer, M.; Zavodsky, Bradley; Molthan, Andrew

    2012-01-01

    The Red, Green, Blue (RGB) Air Mass product has been demonstrated in the GOES ]R Proving Ground as a possible decision aid. Forecasters have been trained on the usefulness of identifying stratospheric intrusions and potential vorticity (PV) anomalies that can lead to explosive cyclogenesis, genesis of mesoscale convective systems (MCSs), or the transition of tropical cyclones to extratropical cyclones. It has also been demonstrated to distinguish different air mass types from warm, low ozone air masses to cool, high ozone air masses and the various interactions with the PV anomalies. To assist the forecasters in understanding the stratospheric contribution to high impact weather systems, the Atmospheric Infrared Sounder (AIRS) Total Column Ozone Retrievals have been made available as an operational tool. These AIRS retrievals provide additional information on the amount of ozone that is associated with the red coloring seen in the RGB Air Mass product. This paper discusses how the AIRS retrievals can be used to quantify the red coloring in RGB Air Mass product. These retrievals can be used to diagnose the depth of the stratospheric intrusions associated with different types of weather systems and provide the forecasters decision aid tools that can improve the quality of forecast products.

  1. IBuoy: Expendable Echo Sounder Buoy with Satellite Data Telemetry

    NASA Astrophysics Data System (ADS)

    Greenspan, D. G.; Porter, D. L.; Chayes, D. N.

    2012-12-01

    The IBuoy is a small expendable buoy platform with satellite data telemetry that can be deployed for different measurements, such as a wave spectrum (Porter and Keller, 2012). The IBuoy in its wave measuring version allows a user to deploy a small float, (25 cm high, 30 cm in diameter, 2.8 kg), which measures the instrument's motion for 20 minutes, processes the data for 5 minutes, and telemeters the processed data via Iridium modem to the user. In the spring of 2012 this system was modified by replacing the internal motion sensor with a connection to the Lamont-Doherty Earth Observatory's (LDEO) prototype Seafloor Sounding in Polar and Remote (SSPARR) echo sounder (Anderson et. al, 2005). From May 3 through May 19, 2012, this prototype was deployed nine times during the NSF-funded Switchyard field program at thin hole rosette sites (Smethie et. al, 2011). At three sites it was deployed in the beacon-mode, and at six other sites in the SSPARR mode with one of the sites being within ~400 km of the North Pole. In beacon-mode the IBuoy reports positions over time allowing accurate estimates of true ice motion. When it is in the beacon- and depth-mode, an acoustic transducer is deployed through a 12 inch hole in the ice and connected to the SSPARR sounder with the IBuoy on the ice surface. In this configuration it measures the water depth from the submerged transducer to the ocean floor below. Now that the concept has successfully been tested, the goal is to deploy similar IBuoy/SSPARRs at a number of sites for a season and collect positional data and depth soundings as the ice moves. The IBuoy concept provides a highly capable inexpensive platform that can be configured for a variety of measurements. References: Porter, D. L. and K. H. Keller, "IBuoy: Expendable Short Time Duration Wave Buoy with Satellite Data Telemetry," OCEANS '12, Hampton Roads, VA, 14-19 October, 2012. Smethie, W.M. Jr., D. Chayes, R. Perry, and P. Schlosser. 2011. A lightweight vertical rosette

  2. Development and Application of Hyperspectral Infrared Ozone Retrieval Products for Operational Meteorology

    NASA Technical Reports Server (NTRS)

    Berndt, Emily; Zavodsky, Bradley; Jedlovec, Gary

    2015-01-01

    Cyclogenesis is a key forecast challenge at operational forecasting centers such as WPC and OPC, so these centers have a particular interest in unique products that can identify key storm features. In some cases, explosively developing extratropical cyclones can produce hurricane force, non-convective winds along the East Coast and north Atlantic as well as the Pacific Ocean, with the potential to cause significant damage to life and property. Therefore, anticipating cyclogenesis for these types of storms is crucial for furthering the NOAA goal of a "Weather Ready Nation". Over the last few years, multispectral imagery (i.e. RGB) products have gained popularity among forecasters. The GOES-R satellite champion at WPC/OPC has regularly evaluated the Air Mass RGB products from GOES Sounder, MODIS, and SEVIRI to aid in forecasting cyclogenesis as part of ongoing collaborations with SPoRT within the framework of the GOES-R Proving Ground. WPC/OPC has used these products to identify regions of stratospheric air associated with tropopause folds that can lead to cyclogenesis and hurricane force winds. RGB products combine multiple channels or channel differences into multi-color imagery in which different colors represent a particular cloud or air mass type. Initial interaction and feedback from forecasters evaluating the legacy Air Mass RGBs revealed some uncertainty regarding what physical processes the qualitative RGB products represent and color interpretation. To enhance forecaster confidence and interpretation of the Air Mass RGB, NASA SPoRT has transitioned a total column ozone product from AIRS retrievals to the WPC/OPC. The use of legacy AIRS demonstrates future JPSS capabilities possible with CrIS or OMPS. Since stratospheric air can be identified by anomalous potential vorticity and warm, dry, ozone-rich air, hyperspectral infrared sounder ozone products can be used in conjunction with the Air Mass RGB for identifying the role of stratospheric air in explosive

  3. Real-time Data Processing and Visualization for the Airborne Scanning High-resolution Interferometer Sounder (S-HIS)

    NASA Astrophysics Data System (ADS)

    Taylor, J. K.; Revercomb, H. E.; Hoese, D.; Garcia, R. K.; Smith, W. L.; Weisz, E.; Tobin, D. C.; Best, F. A.; Knuteson, R. O.; Sullivan, D. V.; Barnes, C. M.; Van Gilst, D. P.

    2015-12-01

    The Hurricane and Severe Storm Sentinel (HS3) is a five-year NASA mission targeted to enhance the understanding of the formation and evolution of hurricanes in the Atlantic basin. Measurements were made from two NASA Global Hawk Unmanned Aircraft Systems (UAS) during the 2012 through 2014 hurricane seasons, with flights conducted from the NASA Wallops Flight Facility. The Global Hawk aircraft are capable of high altitude flights with durations of up to 30 hours, which allow extensive observations over distant storms, not typically possible with manned aircraft. The two NASA Global Hawks were equipped with instrument suites to study the storm environment, and inner core structure and processes, respectively. The Scanning High-resolution Interferometer Sounder (S-HIS), designed and built by the University of Wisconsin (UW) Space Science and Engineering Center (SSEC), measures emitted thermal radiation at high spectral resolution between 3.3 and 18 microns. The radiance measurements are used to obtain temperature and water vapor profiles of the Earth's atmosphere. The S-HIS spatial resolution is 2 km at nadir, across a 40 km ground swath from a nominal altitude of 20 kilometers. Since 1998, the S-HIS has participated in 33 field campaigns and has proven to be extremely dependable, effective, and highly accurate. It has flown on the NASA ER-2, DC-8, Proteus, WB-57, and Global Hawk airborne platforms. The UW S-HIS infrared sounder instrument is equipped with a real-time ground data processing system capable of delivering atmospheric profiles, radiance data, and engineering status to mission support scientists - all within less than one minute from the time of observation. This ground data processing system was assembled by a small team using existing software and proven practical techniques similar to a satellite ground system architecture. This summary outlines the design overview for the system and illustrates the data path, content, and outcomes.

  4. Step-Scan T-Cell Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) for Monitoring Environmental Air Pollutants

    NASA Astrophysics Data System (ADS)

    Liu, Lixian; Mandelis, Andreas; Melnikov, Alexander; Michaelian, Kirk; Huan, Huiting; Haisch, Christoph

    2016-07-01

    Air pollutants have adverse effects on the Earth's climate system. There is an urgent need for cost-effective devices capable of recognizing and detecting various ambient pollutants. An FTIR photoacoustic spectroscopy (FTIR-PAS) method based on a commercial FTIR spectrometer developed for air contamination monitoring will be presented. A resonant T-cell was determined to be the most appropriate resonator in view of the low-frequency requirement and space limitations in the sample compartment. Step-scan FTIR-PAS theory for regular cylinder resonator has been described as a reference for prediction of T-cell vibration principles. Both simulated amplitude and phase responses of the T-cell show good agreement with measurement data Carbon dioxide IR absorption spectra were used to demonstrate the capacity of the FTIR-PAS method to detect ambient pollutants. The theoretical detection limit for carbon dioxide was found to be 4 ppmv. A linear response to carbon dioxide concentration was found in the range from 2500 ppmv to 5000 ppmv. The results indicate that it is possible to use step-scan FTIR-PAS with a T-cell as a quantitative method for analysis of ambient contaminants.

  5. Infrared radiant burner

    SciTech Connect

    Vigneau, D.L.

    1984-03-06

    An infrared radiant burner uses a porous, fibrous refractory board matrix supported by two pairs of frame members, forming a gas-air mixture chamber between a flat sheet, the frame supports, and the matrix. The hollow frame members receive a noncombustible gas that is directed out through a narrow path along the sides of the matrix. The burner's air knife construction grips the matrix edge so as to prevent gas leakage while delivering air through the air knives around the burner periphery.

  6. Temperature and dust profiles in Martian dust storm conditions retrieved from Mars Climate Sounder measurements

    NASA Astrophysics Data System (ADS)

    Kleinboehl, A.; Kass, D. M.; Schofield, J. T.; McCleese, D. J.

    2013-12-01

    Mars Climate Sounder (MCS) is a mid- and far-infrared thermal emission radiometer on board the Mars Reconnaissance Orbiter. It measures radiances in limb and nadir/on-planet geometry from which vertical profiles of atmospheric temperature, water vapor, dust and condensates can be retrieved in an altitude range from 0 to 80 km and with a vertical resolution of ~5 km. Due to the limb geometry used as the MCS primary observation mode, retrievals in conditions with high aerosol loading are challenging. We have developed several modifications to the MCS retrieval algorithm that will facilitate profile retrievals in high-dust conditions. Key modifications include a retrieval option that uses a surface pressure climatology if a pressure retrieval is not possible in high dust conditions, an extension of aerosol retrievals to higher altitudes, and a correction to the surface temperature climatology. In conditions of a global dust storm, surface temperatures tend to be lower compared to standard conditions. Taking this into account using an adaptive value based on atmospheric opacity leads to improved fits to the radiances measured by MCS and improves the retrieval success rate. We present first results of these improved retrievals during the global dust storm in 2007. Based on the limb opacities observed during the storm, retrievals are typically possible above ~30 km altitude. Temperatures around 240 K are observed in the middle atmosphere at mid- and high southern latitudes after the onset of the storm. Dust appears to be nearly homogeneously mixed at lower altitudes. Significant dust opacities are detected at least up to 70 km altitude. During much of the storm, in particular at higher altitudes, the retrieved dust profiles closely resemble a Conrath-profile.

  7. Thermal Inertia Mapping Using Mars Climate Sounder Measurements.

    NASA Astrophysics Data System (ADS)

    Piqueux, S.; Kleinboehl, A.; Golombek, M. P.

    2014-12-01

    Previous work has shown inter-seasonal variations of the apparent thermal inertia at virtually all Martian latitudes. Because thermal inertia is mainly controlled by low variability parameters (e.g., grain sizes, degree of induration, rock abundance), these variations are usually interpreted in terms of subsurface layering and atmospheric contributions. Using atmospherically corrected surface temperatures at 32 μm wavelength (channel B1) from the Mars Climate Sounder (MCS) onboard Mars Reconnaissance Orbiter, we analyze the inter-seasonal variations of the apparent thermal inertia. We show that most of the previously observed inertia variations are eliminated, indicating that a simple homogeneous regolith structure is sufficient to explain most of the measurements. Also, as expected, a fraction of the observed variations remain, especially at high latitudes. This is consistent with subsurface layering involving water ice below dry regolith inferred from other measurement techniques and modeling. This work strengthens our ability to identify and characterize surface/subsurface material thermal inertias, layering and physical heterogeneities in the Martian surface layer, and will help eliminate seasonal striping on high-resolution inertia maps. In addition to a global scale analysis, we will discuss observations in western Elysium Planitia where the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander is planned to land in September 2016. We will provide predictions of the surface layer thermophysical properties, which are required for safe landing and successful scientific operations on the ground.

  8. Coherent launch-site atmospheric wind sounder: theory and experiment.

    PubMed

    Hawley, J G; Targ, R; Henderson, S W; Hale, C P; Kavaya, M J; Moerder, D

    1993-08-20

    The coherent launch-site atmospheric wind sounder (CLAWS) is a lidar atmospheric wind sensor designed to measure the winds above space launch facilities to an altitude of 20 km. In our development studies, lidar sensor requirements are defined, a system to meet those requirements is defined and built, and the concept is evaluated, with recommendations for the most feasible and cost-effective lidar system for use as an input to a guidance and control system for missile or spacecraft launches. The ability of CLAWS to meet NASA goals for increased safety and launch/mission flexibility is evaluated in a field test program at Kennedy Space Center (KSC) in which we investigate maximum detection range, refractive turbulence, and aerosol backscattering efficiency. The Nd:YAG coherent lidar operating at 1.06 µm with 1-J energy per pulse is able to make real-time measurements of the three-dimensional wind field at KSC to an altitude of 26 km, in good agreement with our performance simulations. It also shows the height and thickness of the volcanic layer caused by the volcanic eruption of Mount Pinatubo in the Philippines. PMID:20830118

  9. Validation of UARS Microwave Limb Sounder ClO Measurements

    NASA Technical Reports Server (NTRS)

    Waters, J. W.; Read, W. G.; Froidevaux, L.; Lungu, T. A.; Perun, V. S.; Stachnik, R. A.; Jarnot, R. F.; Cofield, R. E.; Fishbein, E. F.; Flower, D. A.; Burke, J. R.; Hardy, J. C.; Nakamura, L. L.; Ridenoure, B. P.; Shippony, Z.; Thurstans, R. P.; Thurstans, R. P.; Avallone, L. M.; Toohey, D. W.; deZafra, R. L.; Shindell, D. T.

    1996-01-01

    Validation of stratospheric ClO measurements by the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is described. Credibility of the measurements is established by (1) the consistency of the measured ClO spectral emission line with the retrieved ClO profiles and (2) comparisons of ClO from MLS with that from correlative measurements by balloon-based, ground-based, and aircraft-based instruments. Values of "noise" (random), "scaling" (multiplicative), and "bias" (additive) uncertainties are determined for the Version 3 data, in the first version public release of the known artifacts in these data are identified. Comparisons with correlative measurements indicate agreement to within the combined uncertainties expected for MLS and the other measurements being compared. It is concluded that MLS Version 3 ClO data, with proper consideration of the uncertainties and "quality" parameters produced with these data, can be used for scientific analyses at retrieval surfaces between 46 and 1 hPa (approximately 20-50 km in height). Future work is planned to correct known problems in the data and improve their quality.

  10. The Upper Atmosphere Research Satellite microwave limb sounder instrument

    NASA Technical Reports Server (NTRS)

    Barath, F. T.; Chavez, M. C.; Cofield, R. E.; Flower, D. A.; Frerking, M. A.; Gram, M. B.; Harris, W. M.; Holden, J. R.; Jarnot, R. F.; Kloezeman, W. G.

    1993-01-01

    The microwave limb sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is the first satellite experiment using limb sounding techniques at microwave frequencies. Primary measurement objectives are stratospheric ClO, O3, H2O, temperature, and pressure. Measurements are of thermal emission: all are performed simultaneously and continuously and are not degraded by ice clouds or volcanic aerosols. The instrument has a 1.6-m mechanically scanning antenna system and contains heterodyne radiometers in spectral bands centred near 63, 183, and 205 GHz. The radiometers operate at ambient temperature and use Schottky-diode mixers with local oscillators derived from phase-locked Gunn oscillators. Frequency tripling by varactor multipliers generates the 183- and 205-GHz local oscillators, and quasi-optical techniques inject these into the mixers. Six 15-channel filter banks spectrally resolve stratospheric thermal emission lines and produce an output spectrum every 2 s. Thermal stability is sufficient for 'total power' measurements which do not require fast chopping. Radiometric calibration, consisting of measurements of cold space and an internal target, is performed every 65-s limb scan. Instrument in-orbit performance has been excellent, and all objectives are being met.

  11. Scanning Mechanism of the FY-3 Microwave Humidity Sounder

    NASA Technical Reports Server (NTRS)

    Schmid, Manfred; Jing, Li; Hehr, Christian

    2010-01-01

    Astrium GmbH Germany, developed the scanning equipment for the instrument package of the MicroWave Humidity Sounder (MWHS) flying on the FY-3 meteorological satellite (FY means Feng Yun, Wind and Cloud) in a sun-synchronized orbit of 850-km altitude and at an inclination of 98.8 . The scanning mechanism rotates at variable velocity comprising several acceleration / deceleration phases during each revolution. The Scanning Mechanism contains two output shafts, each rotating a parabolic offset Antenna Reflector. The mechanism is operated in closed loop by means of redundant control electronics. MWHS is a sounding radiometer for measurement of global atmospheric water vapour profiles. An Engineering Qualification Model was developed and qualified and a first Flight Model was launched early 2008. The system is now working for more than two years successful in orbit. A second Flight Model of the Antenna Scanning Mechanism and of its associated control electronics was built and delivered to the customer for application on the follow-on spacecraft that will be launched by the end of 2010.

  12. The Mars Climate Sounder In-Flight Positioning Anomaly

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.; Kass, David

    2008-01-01

    The paper discusses the Mars Climate Sounder (MCS) instrument s in-flight positioning errors and presents background material about it. A short overview of the instrument s science objectives and data acquisition techniques is provided. The brief mechanical description familiarizes the reader with the MCS instrument. Several key items of the flight qualification program, which had a rigorous joint drive test program but some limitations in overall system testing, are discussed. Implications this might have had for the flight anomaly, which began after several months of flawless space operation, are mentioned. The detection, interpretation, and instrument response to the errors is discussed. The anomaly prompted engineering reviews, renewed ground, and some in-flight testing. A summary of these events, including a timeline, is included. Several items of concern were uncovered during the anomaly investigation, the root cause, however, was never found. The instrument is now used with two operational constraints that work around the anomaly. It continues science gathering at an only slightly diminished pace that will yield approximately 90% of the originally intended science.

  13. Evaluating AIRS Radiometric Error in Non-uniform Scenes using MODIS

    NASA Astrophysics Data System (ADS)

    Pagano, T. S.; Aumann, H. H.

    2014-12-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in 2378 channels ranging in wavelength from 3.7-15.4 um with spectral resolution of better than 1200, and spatial resolution of 13.5 km with global daily coverage. The AIRS was designed to measure temperature and water vapor profiles for improvement in weather forecast and improved parameterization of climate processes. Currently the AIRS Level 1B Radiance Products are assimilated by NWP centers worldwide and have shown considerable forecast improvement. AIRS L1 and L2 products are widely used for studying critical climate processes related to water vapor feedback, atmospheric transport and cloud properties. AIRS trace gas products include ozone profiles, carbon monoxide, and the first global maps of mid-tropospheric carbon dioxide. The AIRS radiances are calibrated using a uniform on-board blackbody and full aperture space view. For this reason, all radiometric measurements assume a uniform scene. As with most instruments, the AIRS 2D spatial response functions (tophat functions) are not flat for all channels, nor are they the same. When viewing a non-uniform scene, this causes a radiometric error that is scene dependent and cannot be removed without knowledge of the scene response. The magnitude of the error depends on the non-uniformity of the AIRS spatial response and the non-uniformity of the scene, but typically only affects about 1% of the data. In this effort we use data from the MODIS instrument to provide information on the scene uniformity that can be used to correct the AIRS data. Early results show we can match the AIRS and MODIS radiances to about 0.6K when we include the AIRS tophat functions in the normalization of the MODIS data (Elliott, Proc SPIE 6296, 2006). The method requires use of different infrared bands in MODIS depending on the channels of AIRS being corrected. Resulting improvement in noise and

  14. Investigation of AIRS and AMSU sounding products in regional numerical weather simulation

    NASA Astrophysics Data System (ADS)

    Hsu, Shen-Cha; Liu, Chian-Yi; Kuo, Szu-Chen

    2016-05-01

    The initial and boundary conditions are critical to the numerical weather prediction (NWP) model. It is known that satellite observations can overcome the limitations of the terrain, especially over the oceans where conventional observations are difficult to obtain. Therefore, the use of satellite data will expect to improve those regions where lack of traditional observation. The Advanced Microwave Sounding Unit (AMSU) and Atmospheric InfraRed Sounder (AIRS) onboard NASA's EOS Aqua satellite, represent microwave and hyperspectral infrared observations, respectively. Both of them may provide atmospheric temperature and moisture soundings with complementary characteristics. For example, AMSU has the advantage to give cloudy retrievals while AIRS may retain the atmospheric gradient due to its finer high spatial resolution. Both data could estimate atmospheric thermodynamic state with substantial accuracy to improve high impact weather forecast In this study, we adopt the Weather Research and Forecasting (WRF) model and the community Gridpoint Statistical Interpolation (GSI) data assimilation system to evaluate the use of AMSU/AIRS retrievals for severe precipitation at Taiwan. The front, UTC 2016/01/05 22Z, is selected to demonstrate the benefit of using sounding data. The preliminary results shows a positive impact on total precipitable water while the time slope may need further investigation.

  15. Reconciling biases and uncertainties of AIRS and MODIS ice cloud properties

    NASA Astrophysics Data System (ADS)

    Kahn, B. H.; Gettelman, A.

    2015-12-01

    We will discuss comparisons of collocated Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) ice cloud optical thickness (COT), effective radius (CER), and cloud thermodynamic phase retrievals. The ice cloud comparisons are stratified by retrieval uncertainty estimates, horizontal inhomogeneity at the pixel-scale, vertical cloud structure, and other key parameters. Although an estimated 27% globally of all AIRS pixels contain ice cloud, only 7% of them are spatially uniform ice according to MODIS. We find that the correlations of COT and CER between the two instruments are strong functions of horizontal cloud heterogeneity and vertical cloud structure. The best correlations are found in single-layer, horizontally homogeneous clouds over the low-latitude tropical oceans with biases and scatter that increase with scene complexity. While the COT comparisons are unbiased in homogeneous ice clouds, a bias of 5-10 microns remains in CER within the most homogeneous scenes identified. This behavior is entirely consistent with known sensitivity differences in the visible and infrared bands. We will use AIRS and MODIS ice cloud properties to evaluate ice hydrometeor output from climate model output, such as the CAM5, with comparisons sorted into different dynamical regimes. The results of the regime-dependent comparisons will be described and implications for model evaluation and future satellite observational needs will be discussed.

  16. Visible and infrared spin scan radiometer atmospheric sounder water vapor and wind fields over Amazonia

    SciTech Connect

    Schmit, T.J.; Brueske, K.F.; Smith, W.L. ); Menzel, W.P. )

    1990-09-20

    Both the mass and motion fields for Amazonia have been depicted using almost exclusively geostationary satellite data. Derived parameters include satellite retrievals of atmospheric temperature and dewpoint temperature, total precipitable water vapor, and cloud and water vapor winds. The capabilities of geostationary satellite data have been demonstrated at least four times a day for the period of May 5-8, 1987, during the Global Tropospheric Experiment/Amazon Boundary Layer Experiment. The satellite-derived information is able to resolve synoptic-scale atmospheric trends in space and time.

  17. Ethane pollution in the UTLS observed with the imaging infrared limb sounder GLORIA

    NASA Astrophysics Data System (ADS)

    Sumińska-Ebersoldt, Olga

    2015-04-01

    Ethane (C2H6) in the atmosphere results from the production and transmission of fossil fuels, biofuel use and biomass burning. Due to its lifetime of 2 - 3 months, ethane is a significant indicator and tracer of industrial pollution and enables investigation of transport and mixing in the UTLS region. During the TACTS/ESMVal flight over Arabian Sea and Arabian Peninsula in summer 2012, GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) detected two layers (at 10-12 km and 12-14 km altitude) and two vertical plums of enhanced ethane with mixing ratios of about 1000 ppt. The spatial distribution cross sections of ethane retrieved from GLORIA chemistry mode measurements show good correlation with numerous trace gases sampled with in-situ instruments during the flight. Based on the data and the climatology, we evaluate here the sources of the ethane mixing ratio enhancements with backward trajectory calculations and investigate an impact of outflow of pollutants from the Asian summer monsoon on the composition of the UTLS in the flight region.

  18. High resolution infrared radiation sounder for the Nimbus F spacecraft. [design and fabrication of protoflight unit

    NASA Technical Reports Server (NTRS)

    Koenig, E. W.

    1973-01-01

    The activities on the HIRS program are described for the period of July through September, 1973. Completion of design activity and early fabrication effort on the protoflight unit were the major efforts. Operation of the engineering model in spacecraft integration tests was completed during July and August, after which the unit was returned for added test and evaluation.

  19. Regression analysis in modeling of air surface temperature and factors affecting its value in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Rajab, Jasim Mohammed; Jafri, Mohd. Zubir Mat; Lim, Hwee San; Abdullah, Khiruddin

    2012-10-01

    This study encompasses air surface temperature (AST) modeling in the lower atmosphere. Data of four atmosphere pollutant gases (CO, O3, CH4, and H2O) dataset, retrieved from the National Aeronautics and Space Administration Atmospheric Infrared Sounder (AIRS), from 2003 to 2008 was employed to develop a model to predict AST value in the Malaysian peninsula using the multiple regression method. For the entire period, the pollutants were highly correlated (R=0.821) with predicted AST. Comparisons among five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the southwest monsoon (SWM) season, within 1.3 K, and for in situ data, within 1 to 2 K. The validation results of AST with AST from AIRS showed high correlation coefficient (R=0.845 to 0.918), indicating the model's efficiency and accuracy. Statistical analysis in terms of β showed that H2O (0.565 to 1.746) tended to contribute significantly to high AST values during the northeast monsoon season. Generally, these results clearly indicate the advantage of using the satellite AIRS data and a correlation analysis study to investigate the impact of atmospheric greenhouse gases on AST over the Malaysian peninsula. A model was developed that is capable of retrieving the Malaysian peninsulan AST in all weather conditions, with total uncertainties ranging between 1 and 2 K.

  20. Performance of the AIRS Pulse Tube Coolers and Instrument—A First Year in Space

    NASA Astrophysics Data System (ADS)

    Ross, R. G.; Rodriguez, J. I.

    2004-06-01

    Launched on NASA's Aqua platform on May 4, 2002, JPL's Atmospheric Infrared Sounder (AIRS) instrument has completed a successful first year in space and captured a number of important lessons. AIRS is designed to make precision measurements of air temperature over the surface of the Earth and uses a redundant pair of TRW 55 K pulse tube cryocoolers to cool its sensitive IR focal plane. Soon after the instrument went cold, contamination of cryogenic surfaces led to increased cooler loads and the need for decontamination cycles. In addition, single event transients occurred while passing through the South Atlantic Anomaly (SAA) necessitating corrective actions. In November 2002 the fundamental operating strategy of the AIRS instrument was changed from the original strategy of running a single cooler and having the second cooler as a non-operating backup. Instead, based on a new system-level reliability analysis, both coolers began operation simultaneously. This change resolved the contamination and SAA driven interruptions and has enabled unprecedented levels of continuous science measurements. A review of the AIRS instrument cryogenic performance over the past year is presented including its contamination buildup and interrupt history. The reliability analysis conducted to justify two-cooler operation is also reviewed.

  1. Validation of AIRS/AMSU Cloud Retrievals Using MODIS Cloud Analyses

    NASA Technical Reports Server (NTRS)

    Molnar, Gyula I.; Susskind, Joel

    2005-01-01

    The AIRS/AMSU (flying on the EOS-AQUA satellite) sounding retrieval methodology allows for the retrieval of key atmospheric/surface parameters under partially cloudy conditions (Susskind et al.). In addition, cloud parameters are also derived from the AIRS/AMSU observations. Within each AIRS footprint, cloud parameters at up to 2 cloud layers are determined with differing cloud top pressures and effective (product of infrared emissivity at 11 microns and physical cloud fraction) cloud fractions. However, so far the AIRS cloud product has not been rigorously evaluated/validated. Fortunately, collocated/coincident radiances measured by MODIS/AQUA (at a much lower spectral resolution but roughly an order of-magnitude higher spatial resolution than that of AIRS) are used to determine analogous cloud products from MODIS. This allows us for a rather rare and interesting possibility: the intercomparisons and mutual validation of imager vs. sounder-based cloud products obtained from the same satellite positions. First, we present results of small-scale (granules) instantaneous intercomparisons. Next, we will evaluate differences of temporally averaged (monthly) means as well as the representation of inter-annual variability of cloud parameters as presented by the two cloud data sets. In particular, we present statistical differences in the retrieved parameters of cloud fraction and cloud top pressure. We will investigate what type of cloud systems are retrieved most consistently (if any) with both retrieval schemes, and attempt to assess reasons behind statistically significant differences.

  2. Validation of AIRS version 6 temperature profiles and surface-based inversions over Antarctica using Concordiasi dropsonde data

    NASA Astrophysics Data System (ADS)

    Boylan, Patrick; Wang, Junhong; Cohn, Stephen A.; Fetzer, Eric; Maddy, Eric S.; Wong, Sun

    2015-02-01

    During the 2010 Concordiasi field experiment, 635 dropsondes were released from the lower stratosphere providing in situ atmospheric profiles from the release height (~60 hPa) to the surface over Antarctica. They provide a unique data set of high vertical resolution temperature profiles over the entire Antarctic continent and surrounding ocean. This study uses temperature profiles and derived surface-based inversion (SBI) properties from the sonde data set to evaluate Atmospheric Infrared Sounder (AIRS) versions 5 (v5) and 6 (v6) temperature profiles. A total of 1486 matched pairs of profiles are available for analysis. The AIRS averaging kernel, representing the AIRS measurement sensitivity, is applied to the dropsonde profiles. The AIRS data are compared to kernel-averaged dropsonde profiles and found, on average, to have a small cold bias (~0.5°C) (for v6) in the troposphere. AIRS v6 is improved over v5 with both profile-averaged bias and root-mean-square errors reduced by over 25%. Compared to the kernel-averaged dropsonde profiles, AIRS v6 accurately detects the existence of SBIs in 79% of the profiles and agrees on the inversion depth 79% of the time. AIRS correctly identifies SBIs in 59% of cases when compared to the full-resolution sonde. AIRS systematically underestimates the SBI intensity. This is due to warmer reported AIRS surface air temperatures (Ta) than Ta measured with the dropsonde. Replacement of AIRS Ta with that measured by the dropsonde improves the agreement in both SBI detection and intensity. If AIRS Ta could be improved, AIRS has the potential to be a stand-alone SBI detection tool over Antarctica.

  3. Trends in Surface Temperature from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Aumann, H. H.

    2014-12-01

    To address possible causes of the current hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We find a monotonic positive trend for the land temperature but not for the ocean temperature. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The results are compared with the model studies. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  4. Validation of Aura Microwave Limb Sounder HCl Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Jiang, Y. B.; Lambert, A.; Livesey, N. J.; Read, W. G.; Waters, J. W.; Fuller, R. A.; Marcy, T. P.; Popp, P. J.; Gao, R. S.; Fahey, D. W.; Jucks, K. W.; Stachnik, R. A.; Toon, G. C.; Christensen, L. E.; Webster, C. R.; Bernath, P. F.; Boone, C. D.; Walker, K. A.; Pumphrey, H. C.; Harwood, R. S.; Manney, G. L.; Schwartz, M. J.; Daffer, W. H.; Drouin, B. J.

    2008-01-01

    The Earth Observing System (EOS) Microwave Limb Sounder (MLS) aboard the Aura satellite has provided daily global HCl profiles since August 2004. We provide a characterization of the resolution, random and systematic uncertainties, and known issues for the version 2.2 MLS HCl data. The MLS sampling allows for comparisons with many (1500 to more than 3000) closely matched profiles from the Halogen Occultation Experiment (HALOE) and Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). These data sets provide HCl latitudinal distributions that are, overall, very similar to those from (coincident) MLS profiles, although there are some discrepancies in the upper stratosphere between the MLS and HALOE gradients. As found in previous work, MLS and ACE HCl profiles agree very well (within approximately 5%, on average), but the MLS HCl abundances are generally larger (by 10-20%) than HALOE HCl. The bias versus HALOE is unlikely to arise mostly from MLS, as a similar systematic bias (of order 15%) is not observed between average MLS and balloon-borne measurements of HCl, obtained over Fort Sumner, New Mexico, in 2004 and 2005. At the largest pressure (147 hPa) for MLS HCl, a high bias (approximately 0.2 ppbv) is apparent in analyses of low to midlatitude data versus in situ aircraft chemical ionization mass spectrometry (CIMS) HCl measurements from the Aura Validation Experiment (AVE) campaigns in 2004, 2005, and 2006; this bias is also observed in comparisons of MLS and aircraftHCl/O3 correlations. Good agreement between MLS and CIMS HCl is obtained at 100 to 68 hPa. The recommended pressure range for MLS HCl is from 100 to 0.15 hPa.

  5. The UARS and EOS Microwave Limb Sounder (MLS) Experiments.

    NASA Astrophysics Data System (ADS)

    Waters, J. W.; Read, W. G.; Froidevaux, L.; Jarnot, R. F.; Cofield, R. E.; Flower, D. A.; Lau, G. K.; Pickett, H. M.; Santee, M. L.; Wu, D. L.; Boyles, M. A.; Burke, J. R.; Lay, R. R.; Loo, M. S.; Livesey, N. J.; Lungu, T. A.; Manney, G. L.; Nakamura, L. L.;  Perun, V. S.;  Ridenoure, B. P.;  Shippony, Z.;  Siegel, P. H.;  Thurstans, R. P.;  Harwood, R. S.;  Pumphrey, H. C.;  Filipiak, M. J.

    1999-01-01

    The Microwave Limb Sounder (MLS) experiments obtain measurements of atmospheric composition, temperature, and pressure by observations of millimeter- and submillimeter-wavelength thermal emission as the instrument field of view is scanned through the atmospheric limb. Features of the measurement technique include the ability to measure many atmospheric gases as well as temperature and pressure, to obtain measurements even in the presence of dense aerosol and cirrus, and to provide near-global coverage on a daily basis at all times of day and night from an orbiting platform. The composition measurements are relatively insensitive to uncertainties in atmospheric temperature. An accurate spectroscopic database is available, and the instrument calibration is also very accurate and stable. The first MLS experiment in space, launched on the (NASA) Upper Atmosphere Research Satellite (UARS) in September 1991, was designed primarily to measure stratospheric profiles of ClO, O3, H2O, and atmospheric pressure as a vertical reference. Global measurement of ClO, the predominant radical in chlorine destruction of ozone, was an especially important objective of UARS MLS. All objectives of UARS MLS have been accomplished and additional geophysical products beyond those for which the experiment was designed have been obtained, including measurement of upper-tropospheric water vapor, which is important for climate change studies. A follow-on MLS experiment is being developed for NASA's Earth Observing System (EOS) and is scheduled to be launched on the EOS CHEMISTRY platform in late 2002. EOS MLS is designed for many stratospheric measurements, including HOx radicals, which could not be measured by UARS because adequate technology was not available, and better and more extensive upper-tropospheric and lower-stratospheric measurements.

  6. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This report summarizes and documents the results of the 12-month phase 1 work effort. The objective of phase 1 was to establish the conceptional definition of the laser atmospheric wind sounder (LAWS) sensor system, including accommodations analyses to ensure compatibility with the Space Station Freedom (SSF) and the Earth Observing System (EOS) Polar Orbiting Platform (POP). Various concepts were investigated with trade studies performed to select the configuration to be carried forward to the phase 2 Preliminary Design Definition. A summary of the LAWS system and subsystem trade studies that were performed leading to the baseline design configuration is presented in the appendix. The overall objective of the LAWS Project is to define, design, and implement an operational space based facility, LAWS, for accurate measurement of Earth wind profiles. Phase 1 addressed three major areas: (1) requirements definition; (2) instrument concepts and configurations; and (3) performance analysis. For the LAWS instrument concepts and configurations, the issues which press the technological state of the art are reliable detector lifetime and laser performance and lifetime. Lag angle compensation, pointing accuracy, satellite navigation, and telescope design are significant technical issues, but they are considered to be currently state of the art. The primary issues for performance analysis concern interaction with the atmosphere in terms of backscatter and attenuation, wind variance, and cloud blockage. The phase 1 tasks were formulated to address these significant technical issues and demonstrate the technical feasibility of the LAWS concept. Primary emphasis was placed on analysis/trade and identification of candidate concepts. Promising configurations were evaluated for performance, sensitivities, risks, and budgetary costs. Lockheed's baseline LAWS configuration is presented.

  7. Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 2

    NASA Astrophysics Data System (ADS)

    1990-04-01

    This report summarizes and documents the results of the 12-month phase 1 work effort. The objective of phase 1 was to establish the conceptional definition of the laser atmospheric wind sounder (LAWS) sensor system, including accommodations analyses to ensure compatibility with the Space Station Freedom (SSF) and the Earth Observing System (EOS) Polar Orbiting Platform (POP). Various concepts were investigated with trade studies performed to select the configuration to be carried forward to the phase 2 Preliminary Design Definition. A summary of the LAWS system and subsystem trade studies that were performed leading to the baseline design configuration is presented in the appendix. The overall objective of the LAWS Project is to define, design, and implement an operational space based facility, LAWS, for accurate measurement of Earth wind profiles. Phase 1 addressed three major areas: (1) requirements definition; (2) instrument concepts and configurations; and (3) performance analysis. For the LAWS instrument concepts and configurations, the issues which press the technological state of the art are reliable detector lifetime and laser performance and lifetime. Lag angle compensation, pointing accuracy, satellite navigation, and telescope design are significant technical issues, but they are considered to be currently state of the art. The primary issues for performance analysis concern interaction with the atmosphere in terms of backscatter and attenuation, wind variance, and cloud blockage. The phase 1 tasks were formulated to address these significant technical issues and demonstrate the technical feasibility of the LAWS concept. Primary emphasis was placed on analysis/trade and identification of candidate concepts. Promising configurations were evaluated for performance, sensitivities, risks, and budgetary costs. Lockheed's baseline LAWS configuration is presented.

  8. Validation of UARS Microwave Limb Sounder Ozone Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Read, W. G.; Lungu, T. A.; Cofield, R. E.; Fishbein, E. F.; Flower, D. A.; Jarnot, R. F.; Ridenoure, B. P.; Shippony, Z.; Waters, J. W.; Margitan, J. J.; McDermid, I. S.; Stachnik, R. A.; Peckham, G. E.; Braathen, G.; Deshler, T.; Fishman, J.; Hofmann, D. J.; Oltmans, S. J.

    1996-01-01

    This paper describes the validation of ozone data from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS). The MLS ozone retrievals are obtained from the calibrated microwave radiances (emission spectra) in two separate bands, at frequencies near 205 and 183 GHz. Analyses described here focus on the MLS Version 3 data (the first set of files made publicly available). We describe results of simulations performed to assess the quality of the retrieval algorithms, in terms of both mixing ratio and radiance closure. From actual MLS observations, the 205-GHz ozone retrievals give better closure (smaller radiance residuals) than that from the 183-GHz measurements and should be considered more accurate from the calibration aspects. However, the 183-GHz data are less noise limited in the mesosphere and can provide the most useful scientific results in that region. We compare the retrieved 205-GHz ozone profiles in the middle-to lower stratosphere to ozonesonde measurements at a wide range of latitudes and seasons. Ground-based lidar data from Table Mountain, California, provide a good reference for comparisons at higher altitudes. Based on these analyses, comparisons with balloon-borne measurements and others, as well as a detailed budget of estimated uncertainties, MLS results appear to be generally of high quality, with some biases worth mentioning. Results for the lowermost stratosphere (approx. 50 to 100 bPa) are still in need of improvement. A set of estimated precision and accuracy values is derived for the MLS ozone data sets. We also comment on recent updates in the retrieval algorithms and their impact on ozone values.

  9. Mare volcanism: Reinterpretation based on Kaguya Lunar Radar Sounder data

    NASA Astrophysics Data System (ADS)

    Oshigami, Shoko; Watanabe, Shiho; Yamaguchi, Yasushi; Yamaji, Atsushi; Kobayashi, Takao; Kumamoto, Atsushi; Ishiyama, Ken; Ono, Takayuki

    2014-05-01

    The Lunar Radar Sounder (LRS) onboard Kaguya (SELENE) detected widespread horizontal reflectors under some nearside maria. Previous studies estimated that the depths of the subsurface reflectors were up to several hundreds of meters and suggested that the reflectors were interfaces between mare basalt units. The comparison between the reflectors detected in the LRS data and surface age maps indicating the formation age of each basalt unit allows us to discuss the lower limit volume of each basalt unit and its space and time variation. We estimated volumes of basalt units in the ages of 2.7 Ga to 3.8 Ga in the nearside maria including Mare Crisium, Mare Humorum, Mare Imbrium, Mare Nectaris, Mare Serenitatis, Mare Smythii, and Oceanus Procellarum. The lower limit volumes of the geologic units estimated in this study were on the order of 103 to 104 km3. This volume range is consistent with the total amount of erupted lava flows derived from numerical simulations of thermal erosion models of lunar sinuous rille formation and is also comparable to the average flow volumes of continental flood basalt units formed after the Paleozoic and calculated flow volumes of Archean komatiite flows on the Earth. The lower limits of average eruption rates estimated from the unit volumes were on the order of 10-5 to 10-3 km3/yr. The estimated volumes of the geologic mare units and average eruption rate showed clear positive correlations with their ages within the same mare basin, while they vary among different maria compared within the same age range.

  10. Improving AIRS radiance spectra in high contrast scenes using MODIS

    NASA Astrophysics Data System (ADS)

    Pagano, Thomas S.; Aumann, Hartmut H.; Manning, Evan M.; Elliott, Denis A.; Broberg, Steven E.

    2015-09-01

    The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. AIRS acquires hyperspectral infrared radiances in 2378 channels ranging in wavelength from 3.7-15.4 um with spectral resolution of better than 1200, and spatial resolution of 13.5 km with global daily coverage. The AIRS is designed to measure temperature and water vapor profiles for improvement in weather forecast accuracy and improved understanding of climate processes. As with most instruments, the AIRS Point Spread Functions (PSFs) are not the same for all detectors. When viewing a non-uniform scene, this causes a significant radiometric error in some channels that is scene dependent and cannot be removed without knowledge of the underlying scene. The magnitude of the error depends on the combination of non-uniformity of the AIRS spatial response for a given channel and the non-uniformity of the scene, but is typically only noticeable in about 1% of the scenes and about 10% of the channels. The current solution is to avoid those channels when performing geophysical retrievals. In this effort we use data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument to provide information on the scene uniformity that is used to correct the AIRS data. For the vast majority of channels and footprints the technique works extremely well when compared to a Principal Component (PC) reconstruction of the AIRS channels. In some cases where the scene has high inhomogeneity in an irregular pattern, and in some channels, the method can actually degrade the spectrum. Most of the degraded channels appear to be slightly affected by random noise introduced in the process, but those with larger degradation may be affected by alignment errors in the AIRS relative to MODIS or uncertainties in the PSF. Despite these errors, the methodology shows the ability to correct AIRS radiances in non-uniform scenes under some of the worst case conditions and improves the ability to match

  11. AIRS Products Confirm and Explain Recent Negative Trends of OLR as Observed by CERES

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2010-01-01

    Anomalies and trends of OLR serve as important indicators of climate change. Several satellite based instruments currently provide information related to OLR. CERES, on board the EOS Aqua and Terra satellites, contains broad band radiometers that measure total flux and short-wave flux, from which OLR is determined. AIRS is a high spectral resolution IR sounder on EOS Aqua that measures IR radiances covering most of the spectral interval 650/cm to 2670/cm. These observations enable the determination of detailed information about atmospheric temperature, moisture, and ozone profiles, as well as surface skin temperatures and cloud parameters. The AIRS OLR product is the total flux over the spectral interval 2/cm to 2750/cm computed for the surface and atmospheric state determined from AIRS observations. We compared spatial anomalies and trends of OLR, over the seven year period September 2002 through August 2009, as observed by CERES and computed using Version-5 AIRS products. These two sets of OLR anomalies and trends, obtained in very different ways, agree with each other almost perfectly in essentially every detail. This important finding shows that a very stable high spectral infra-red sounder such as AIRS corroborates the anomalies and trends of OLR obtained from CERES. More significantly, anomalies and trends of the individual geophysical parameters derived from AIRS explain the detailed causes of the anomalies and trends of CERES OLR. Both sets of results show that global mean OLR has been decreasing at a rate of 0.12 W/sq m/yr over the seven year time period under study. Both also confirm that the primary cause of this is due to changes in the tropics, in which OLR has been decreasing at a rate of 0.27 W/sq m/yr. AIRS products show that the decrease of tropical OLR is a result of increasing tropical atmospheric water vapor and cloud cover over that time period studied, which in turn is responding to a very strong La Nina; a event starting in late 2007

  12. Modelling a man-portable air-defence (MANPAD) system with a rosette scan two-colour infrared (IR) and ultraviolet (UV) seeker

    NASA Astrophysics Data System (ADS)

    Kumar, Devinder; Smith, Leon; Richardson, Mark A.; Ayling, Richard; Barlow, Nick

    2014-10-01

    The Ultraviolet (UV) band of the electromagnetic (EM) spectrum has the potential to be used as the host medium for the operation of guided weapons. Unlike in the Infrared (IR), a target propelled by an air breathing jet engine produces no detectable radiation in the UV band, and is opaque to the background UV produced by the Sun. Successful engineering of spectral airborne IR countermeasures (CM) against existing two colour IR seekers has encouraged missile counter-countermeasure (CCM) designers to utilise the silhouette signature of an aircraft in the UV as a means of distinguishing between a true target and a flare CM. In this paper we describe the modelling process of a dual band IR and UV rosette scan seeker using CounterSim, a missile engagement and countermeasure simulation software package developed by Chemring Countermeasures Ltd. Results are shown from various simulated engagements of the dual band MANPAD with a C-130 Hercules modelled by Chemring Countermeasures. These results have been used to estimate the aircrafts' vulnerability to this MANPAD threat. A discussion on possible future optical countermeasures against dual band IR-UV seekers is given in conclusion to the simulation results.

  13. Using Regional Validation from SuomiNet, AMSR-e, and NWP Re-analysis to Assess the Precipitable Water Vapor from AIRS and CrIS for Detecting Extreme Weather Events

    NASA Astrophysics Data System (ADS)

    Roman, J.; Knuteson, R. O.; Ackerman, S. A.; Revercomb, H. E.; Smith, W.; Weisz, E.

    2012-12-01

    The IPCC 4th Assessment found that changes in extreme events, such as droughts, heat waves, and flooding, has occurred and the frequency of such