Angular corrections to satellite data for estimating earth radiation budget

Abstract

Monitoring the spatial and temporal variations of the earth's radiation budget (ERB) is essential for our understanding of climate change. Estimating the ERB using satellite data has proven to be a promising avenue for research in recent years. One of the key issues is to convert radiance that is observed at a specific direction to flux, an integrated quantity over all viewing directions. In many cases it is also desirable to convert the derived flux at one specific illumination angle to the daily average value that is integrated over all illumination angles. This article begins with reviewing several representative angular distribution models (ADMs) for converting top-of-atmosphere (TOA) radiance to flux in both shortwave and longwave spectrum. In the surface radiation budget part, we primarily focus on land surface albedo, including narrowband to broadband conversion, diurnal cycle and snow albedo. Research issues are also discussed.