The NASA GEWEX surface radiation budget project: Dataset validation and climatic signal identification
The NASA GEWEX-SRB (Global Energy and Water cycle Experiment - Surface Radiation Budget) project has produced and archived shortwave and longwave radiative fluxes at the top of atmosphere (TOA) and the Earth's surface at a 1° × 1° resolution continuously for a time span of 24.5 years from July 1983 to December 2007. The latest version of the data in archive is Release 3.0 and is available as 3-hourly, daily and monthly means. Through August, 2011, the Baseline Surface Radiation Network (BSRN) archive has 5969 site-months of ground-measured data from 52 sites around the globe. We first performed quality-check on the original BSRN data and, then processed the data to produce 3-hourly, 3-hourly-monthly, daily and monthly means. The SRB-BSRN comparisons show generally good agreement for both the shortwave and longwave downward fluxes at the Earth's surface. It is found that signals of large-scale climatic variation, such as El Niño Southern Oscillation, can be identified through EOF analysis. Polynomial fitting of order 3 for Southern and Northern Hemispheric and global mean downward shortwave fluxes from 1984 to 2007 shows variability consistent with global dimming through 1980s and brightening thereafter.