Extended Abstract (1.8M)P6.6
The NASA/GEWEX Surface Radiation Budget Dataset
Shashi K. Gupta, AS&M, Hampton, VA; and P. W. Stackhouse, S. J. Cox, J. C. Mikovitz, and M. Chiacchio
A twelve-year-plus (July 1983 to October 1995) global dataset of surface shortwave (SW) and longwave (LW) radiative parameters on a 1°x1° grid has been developed under the NASA/GEWEX Surface Radiation Budget (SRB) Project at the NASA Langley Research Center (LaRC). Both SW and LW fluxes were computed with two algorithms: a primary algorithm and a quality-check algorithm. Cloud properties used in the project were derived on a 1°-resolution using ISCCP pixel-level (DX) datasets. Other meteorological inputs, namely, the temperature and humidity profiles, were taken from the GEOS-1 reanalysis product of the Global Modeling and Assimilation Office at NASA/GSFC. Ozone data were obtained from the TOMS archives. The time-series, limited to October 1995 by the availability of GEOS-1 meteorological products, is being extended to September 2001 with the use of GEOS-4 datasets. Three of the four algorithms provide results on a 3-hourly temporal resolution. The quality-check SW algorithm provides daily values only. All datasets were processed into daily and monthly averages for use in scientific studies. All except quality-check SW data were also processed into monthly/3-hourly averages. Zonal, hemispheric, and global averages were derived for individual months as well as on a climatological basis. The entire dataset is available to the worldwide science community from LaRC Atmospheric Sciences Data Center (ASDC) at http://eosweb.larc.nasa.gov/.
Model derived fluxes were validated at all time resolutions by comparison with ground-based observations obtained from a number of Global Energy Balance Archive (GEBA) and Baseline Surface Radiation Network (BSRN) sites. Longwave fluxes showed good agreement for most sites though SW fluxes exhibited large random errors at some. Analysis of the time series showed occurrence of strong surface flux anomalies during the El Nino episodes in May 1987 and March 1992, and the La Nina episode of July 1988. For later part of the time series, fluxes were compared with those derived from satellite observations under NASA’s Clouds and the Earth’s Radiant Energy System (CERES) project. One set of common algorithms but different input datasets between GEWEX/SRB and CERES processing provided a unique assessment of the effects of meteorological inputs on radiative fluxes. For the May 1987 and July 1988 episodes, surface flux anomalies exhibited strong similarities with corresponding TOA flux anomalies derived from ERBE data. Anomalies related to the Mt. Pinatubo eruption of 1991-92 were also apparent. Global annual averages from this dataset compared well with those from other satellite-derived, GCM-based, and observational datasets. Work is underway to extend the time series to the present and to use improved reanalysis products that are now becoming available.
Poster Session 6, Climatology and Long-Term Studies
Wednesday, 22 September 2004, 2:30 PM-4:30 PM
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