Monday, 12 January 2009
Retrieving Cloud and Radiation Parameters in Near-Real-Time from Global Geostationary Satellite Data
Hall 5 (Phoenix Convention Center)
Cloud property retrievals from passive satellite measurements have been vital to understanding cloud processes and for characterizing clouds and their roles in climate. With the increased use of high-resolution numerical weather prediction models and the need for more quantitative weather information for forecasting and nowcasting, timely delivery of cloud and radiation information is becoming more important. This paper describes a prototype system to provide first 3-hourly, then higher resolution retrievals of cloud properties from full-disk geostationary satellites (GEOSat) around the globe. The GEOSat data, from GOES-11/12, Meteosat-9, MTSAT, and FY-2C, are all calibrated to MODIS radiances and analyzed with the same algorithms to produce a relatively consistent set of retrievals. The derived products include a cloud mask (fractional coverage), cloud phase, cloud base and top heights and pressures, optical depth, ice and liquid water paths and effective particle sizes, an aircraft icing index, surface skin temperature, shortwave and visible albedos, outgoing longwave radiation, and surface radiative fluxes. Similar properties for multilayered clouds are also being generated for data from Meteosat, GOES-12, and MODIS. The Aqua and Terra MODIS data are also being analyzed to provide data in polar regions. Active and passive remote sensing data from the surface, CALIPSO, ICESat, and CloudSat are being used to validate the products. The challenges of producing a reliable dataset, from intercalibration of the satellites to accounting for day-night transitions, are discussed along with presentations of product examples These data products are being used in air safety nowcasting products and are undergoing testing for assimilation into numerical weather prediction models. They should many other uses for weather and energy applications.
Supplementary URL: http://www-angler.larc.nasa.gov/