83rd Annual

Thursday, 13 February 2003
Validation of Langley parameterized algorithms used to derive CERES/TRMM surface radiative fluxes
Shashi K. Gupta, AS&M, Hampton, VA; and D. P. Kratz, A. C. Wilber, and L. C. Nguyen
Poster PDF (1016.9 kB)
Parameterized shortwave (SW) and longwave (LW) algorithms developed at the Langley Research Center have been used for deriving surface radiative fluxes as a part of processing of the Clouds and the Earth’s Radiant Energy System (CERES) data obtained during the flight of the Tropical Rainfall Measuring Mission (TRMM) satellite. Retrieved fluxes were validated on an instantaneous/footprint basis using coincident surface measurements obtained from the ARM/SGP central facility, its network of extended facilities, and several BSRN, CMDL, and SURFRAD sites. Validation was carried out separately for clear-sky and all-sky conditions. For the SW, systematic errors were similar in magnitude for clear-sky and all-sky comparisons but random errors were much larger for all-sky (45-95 Wm-2) than for clear-sky (25-45 Wm-2). For the LW, systematic errors were consistently small for both clear-sky and all-sky ( -5 to -10 Wm-2) and random errors were within 20 Wm-2 for both conditions. In general, comparisons with surface data from the ARM/SGP site (especially the central facility) showed the best agreement. Large systematic errors in SW comparisons for some sites were identified with flaws in the site data. LW fluxes obtained with the present algorithm meet the stated accuracy requirements for climate research.

Supplementary URL: