The surface shortwave net flux from the scanner for radiation budget (SCARAB)

Abstract

Shortwave surface net radiation is usually determined by combining the measurement of insolation with an independent estimate of surface albedo. However, uncertainties associated with each of these quantities may lead to large errors in the value of net surface solar radiation. An alternative approach is to deduce the net solar flux (the term flux is used here as the radiometric quantity flux density) at the surface directly from the budget at the top of the atmosphere, without explicit knowledge of surface albedo. The Satellite Application Facility on Climate Monitoring is a joint project of the German Meteorological Service and other European Meteorological Services dedicated to produce climate data sets using data from instruments onboard of METEOSAT Second Generation and polar orbiting satellites NOAA and METOP. In this context, it is planned to use the Li-Leighton algorithm as a validation tool for the independently derived solar incoming radiation at teh surface and the surface albedo. In the framework of the current development phase of the Satellite Application Facility on Climate Monitoring project, data from the well calibrated Scanner for Radiation Budget are used to apply the Li and Leighton algorithm to compute the shortwave surface net radiation.