TERRA Validation:Saudi Arabian Solar Radiation FluxGround Measurements

OVERVIEW:

The validation data sets consist of measured surface radiation fluxes, ambient air temperature, and relative humidity at twelve stations distributed over the Arabian Peninsula within the Kingdom of Saudi Arabia. The measurements are made with radiometers calibrated on at least an annual basis against an Absolute Cavity Radiometer traceable to the World Radiometric Reference (WRR) of the World Meteorological Organization (WMO). Measurement sample rate 10 seconds, with 5 minute averages of the 10 second samples reported.

One station, the Solar Village, serves as the Network Operations Center, calibration facility, and data retrieval and quality assessment center. The Solar Village station 5-minute data set is complemented by a suite of instruments compatible with the WMO World Climate Research Programme (WCRP) Baseline Surface Radiation Network (BSRN) specifications, including upwelling and downwelling longwave and shortwave fluxes, an absolute cavity radiometer for direct beam measurements, and 1-minute average (of 2 second samples) data.

An AErosol RObotic NETwork (AERONET) CIMEL sunphotometer, on loan from the NASA AERONET network co-ordinator is deployed (as of 24 Feb 1999) at the Solar Village site for aerosol optical depth measurements. A micropulse Lidar (Science and Engineering Services, Inc.) on loan from the NASA Clouds and Earth Radiant Energy Systems (CERES) project team is also programmed to be deployed at the Solar Village site to complement the BSRN and CIMEL instrumentation.

Network Data will be posted on a monthly basis for each station on an NREL developed and maintained Satellite Validation world wide web home page. BSRN data will also be posted on a monthly basis as well on the NREL validation home page, as well as submitted to the BSRN archive in Zurich, Switzerland. CIMEL AERONET data will be available on a near real-time basis from the AERONET world wide web home page maintained by NASA Langley. Micropulse Lidar data will be processed and archived by the CERES NASA/Langley team.

The data will be available to 1) evaluate (compare) surface flux estimates derived from satellite data products at various levels 2) assess radiation climatologies of representative areas examined by the satellite instrumentation 3) assess the accuracy of derived measurement parameters (optical depth, total column water vapor, cloud properties) used in deriving surface fluxes 4) evaluate the sources and magnitudes of bias and random components of error, and thus the total uncertainty in satellite derived products at various stages of the production process.

BSRN Cavity Pyrheliometer Downwelling Longwave Pyrgeometer	The Arabian Peninsula from Space	Network and BSRN Radiation Platform and Data Logger at Solar Village

Solar Village BSRN data will posted at this site; as well as submitted to the BSRN data archive in Zurich Switzerland