Investigations of improvements to an operational GOES-satellite-data-based insolation system using pyranometer data from the U.S. Climate Reference Network (USCRN)

Incident solar radiation at the earth's surface (insolation) is the driving force for the earth's atmospheric and surface systems, including biochemical processes such as photosynthesis and the hydrologic cycle for land. This study details insolation estimates over four continuous seasons from a simple radiative transfer model, employing imager visible data from the geostationary GOES series of satellites, a model developed in the 1980s that has undergone continual upgrades and tests since that time. After an introduction explaining the physics and physical assumptions of this model, recent improvements in spatial and temporal resolution and other model modifications are detailed. Initially a set of current satellite insolation results from years 2014-2015 are compared to those produced for a set of 11 pyranometer measurement locations of the United States Climate Research Network (USCRN) for the years 2003-2004 (Otkin et al., 2005). It is found that the model improvements and modifications on average increase the accuracy of the satellite insolation estimates. Subsequently, insolation estimates from this satellite system are compared to USCRN pyranometer measurements from years 2014 and 2015 at an additional 34 USCRN measurement locations across the conterminous U.S. When satellite data are available for a USCRN location using data from both GOES-East and GOES-West, error statistics from the two satellite sources are compared. Distinctions are made between USCRN locations with differing topography and other relevant physical characteristics. Finally, plans for additional improvements and enhancements of the model are discussed.