A New Global Geostationary Satellite-Based Cloud and Surface Temperature Climate Data Record for CERES

The Clouds and the Earth’s Radiant Energy System (CERES) Project has been monitoring the Earth’s radiation budget since 2000 using 20-km resolution broadband scanning radiometers on the Terra, Aqua, and Suomi NPOESS Preparatory Project (SNPP) Rad polar orbiting satellites. Cloud properties are also determined from the MODIS and VIIRS imagers on those same platforms using the CERES cloud property retrieval system. The cloud properties are used to interpret the top-of-atmosphere (TOA) radiances and to compute shortwave and longwave fluxes at the surface and in the atmosphere. Although the instantaneous retrievals of TOA and surface fluxes can be quite accurate, the radiation budget changes over the course of the day, influenced by solar geometry and changing meteorology, particularly semi-regular diurnal cloud variations, can introduce biases in the daily radiation budget. Because the equatorial crossing times for Terra and Aqua (and SNPP) are 10:30 and 13:30 LT, the extremes of the daily cycle are not observed. To account for the missing hours, a combination of directional models and geostationary satellite (GEOSat) imager data are employed to provide a more accurate estimate of the fluxes at those times. In addition to normalization of the GEOSat-estimated fluxes at the Terra and Aqua overpass times, cloud properties are retrieved hourly at an 8-km resolution between 60°N and 60°S from each GEOSat. The radiances from each satellite are normalized to Aqua MODIS and analyzed with the NASA Langley Satellite ClOud and Radiation Property retrieval System (SatCORPS), which is a version of the CERES cloud retrieval system adapted to non-CERES satellites. The retrieved cloud properties are used to compute the surface and atmospheric radiative fluxes at each hour and provide more accurate estimates of the TOA fluxes before normalization to CERES. Since these retrieved properties are based on a fixed version of the SatCORPS processing and on intercalibrated radiances, they form a climate data record complementary to the CERES polar orbiting cloud data set. This paper provides a description of the retrieved properties, their validation, and availability as well as examples of their consistency and trends