Using Surface Measurements in the Validation and Analysis of the NASA/GEWEX SRB Release 3.0 Data

The NASA/GEWEX SRB (Global Energy and Water cycle Experiment Surface Radiation Budget) project has recently produced a 24.5-year continuous global record of shortwave and longwave radiation flux dataset at TOA and the Earth's surface. The data cover the period from July 1983 to December 2007, and the spatial resolution is 1 degree latitude by 1 degree longitude. The inputs of the current version (Release 3.0) include the GEOS Version 4.0.3 meteorological information and cloud properties derived from ISCCP DX data.

To validate the satellite-based radiation data, we have performed extensive comparisons against the BSRN (Baseline Surface Radiation Network) data. The BSRN data are ground-based measurement of shortwave and longwave radiation fluxes along with other meteorological variables. The original BSRN measurement is made at 1-minute, 2-minute, 3-minute or 5-minute intervals. To make it comparable with the GEWEX-SRB data which are provided as 3-hourly, 3-hourly-monthly, daily and monthly means, the BSRN data are processed to produce means on the same time scales. Prior to the processing, quality-check is performed on the original BSRN data to remove data points that are suspected to be in error. In addition to validation against the BSRN data, we have also compared the GEWEX-SRB data against the WRDC (World Radiation Data Centre) daily and derived monthly mean and GEBA (Global Energy Balance Archive Data) monthly mean fluxes.

In this paper, we present the comparisons between the GEWEX-SRB and BSRN as well as the WRDC and GEBA data on various time scales. Some BSRN sites have nearly continuous records, which enable us to make comparisons of time series and detect possible trend of signals of climate change during the period covered by the data. The results show that the NASA/GEWEX SRB (Release 3.0) data are in generally very good agreement with the BSRN data.