A Cloud Mask for the Atmospheric Infrared Sounder (AIRS) PDF Download

Author: Nicole J. Brubaker
Publisher:
ISBN:
Category :
Languages : en
Pages : 176

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Author:
Publisher:
ISBN:
Category : Numerical weather forecasting
Languages : en
Pages : 0

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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 the atmospheric fields in the surroundings away from the hurricane center at the analysis time. With the improvement of the atmospheric fields, the assimilation of cloud-cleared AIRS gives the smallest root mean square error (RMSE) of hurricane tract 72-hour forecast compared to the AIRS radiances using stand-alone cloud detection and collocated cloud mask cloud detection

Author:
Publisher:
ISBN:
Category : Artificial satellites in earth sciences
Languages : en
Pages : 286

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Author: National Research Council
Publisher: National Academies Press
ISBN: 0309092353
Category : Science
Languages : en
Pages : 187

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The system of satellites in place to provide environmental data-data to monitor events such as forest fires and floods; to make weather predictions; and to assess crops, transportation impacts, fisheries, land-use patterns, sea temperature, and soil moisture, among other things- serves a wide and growing array of users. In the coming years as the next generation of operational environmental satellites in put in orbit, the will be a large expansion in data availability. To ensure that these data serve effectively this broad user community, a new vision for the future of operational environmental satellite data utilization is needed. To help develop approaches for handling this potential data overload, NASA, with technical support from NOAA, asked the NRC to conduct an end-to-end review of issues about the utilization of operational environmental satellite data for 2010 and beyond. This report presents the result of that review. It focuses on ensuring the value of environmental satellite data for addressing specific user needs, distribution of such data, and data access and utilization.

Author: Allen Hung-Lung Huang
Publisher: SPIE-International Society for Optical Engineering
ISBN:
Category : Science
Languages : en
Pages : 444

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Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

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Author:
Publisher: ScholarlyEditions
ISBN: 1464963398
Category : Science
Languages : en
Pages : 4306

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Issues in Earth Sciences, Geology, and Geophysics: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Earth Sciences, Geology, and Geophysics. The editors have built Issues in Earth Sciences, Geology, and Geophysics: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Earth Sciences, Geology, and Geophysics in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Earth Sciences, Geology, and Geophysics: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Author:
Publisher: Institute of Electrical & Electronics Engineers(IEEE)
ISBN:
Category : Science
Languages : en
Pages : 812

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Author: Robert E. Holz
Publisher:
ISBN:
Category :
Languages : en
Pages : 166

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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13

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To understand the radiative impact of tropical thin cirrus clouds, the frequency of occurrence and optical depths of these clouds have been derived. "Thin" cirrus clouds are defined here as being those that are not detected by the operational Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask, corresponding to an optical depth value of approximately 0.3 or smaller, but that are detectable in terms of the cirrus reflectance product based on the MODIS 1.375-micron channel. With such a definition, thin cirrus clouds were present in more than 40% of the pixels flagged as "clear sky" by the operational MODIS cloud mask algorithm. It is shown that these thin cirrus clouds are frequently observed in deep convective regions in the western Pacific. Thin cirrus optical depths were derived from the cirrus reflectance product. Regions of significant cloud fraction and large optical depths were observed in the Northern Hemisphere during the boreal spring and summer and moved southward during the boreal autumn and winter. The radiative effects of tropical thin cirrus clouds were studied on the basis of the retrieved cirrus optical depths, the atmospheric profiles derived from the Atmospheric Infrared Sounder (AIRS) observations, and a radiative transfer model in conjunction with a parameterization of ice cloud spectral optical properties. To understand how these clouds regulate the radiation field in the atmosphere, the instantaneous net fluxes at the top of the atmosphere (TOA) and at the surface were calculated. The present study shows positive and negative net forcings at the TOA and at the surface, respectively. The positive (negative) net forcing at the TOA (surface) is due to the dominance of longwave (shortwave) forcing. Both the TOA and surface forcings are in a range of 0-20 W/sq m, depending on the optical depths of thin cirrus clouds.