Earth System Science Workbench: Global Surface Radiation Data Products

The 2001 program is a radiative transfer model that calculates solar
radiation flux to the surface. The model is based on simple, physical
modeling of the most important radiative processes occurring within
the atmosphere, namely scattering and absorption by clouds,
atmospheric gases and aerosols. Visible spectrum geostationary
satellite imagery is used to compute cloud albedo, the governing cloud
parameter. The repeat coverage of the geostationary satellite data
(approx. one obs. per hour) allows an adequate sampling of the diurnal
cloud variability. Furthermore the models simplicity allows it to be
applied to large data sets. Model results have been compared to
pyranometer measurements from the Dept. of Energy's Atmospheric
Radiation Measurement program and averages better than 7% accuracy for
daily integrated values of downwelling shortwave radiation.

Global surface radiation data products will be made available through
the Earth System Science Workbench (ESSW), specifically shortwave,
photosynthetically-active (PAR), and ultraviolet (UV) radiation
fields. These data are derived from GOES VISSR/VAS, AVHRR, and
TOMS/UARS measurements. In the future, the radiation products will
also be derived from MODIS, CERES, AIRS, and ARS/CHEM measurements, as
they become available.