A Global Agroclimatology Data Base: Thirty Plus Years of Satellite-Derived Solar Insolation and Assimilation Model Meteorological Parameters.

A primary objective of NASA’s Prediction of Worldwide Energy Resource (POWER) project is to facilitate the use of NASA Earth Science data holdings within the energy, agricultural, and architectural industries. To this end solar data from several NASA projects and metrological data from a NASA assimilation model have long been reformatted and made available on a global 1-degree latitude, longitude grid via a user friendly web based data portal (http://power.larc.nasa.gov).  Potential users can access solar and metrological data in a column formatted DSSAT ASCII format by entering single site specific coordinates or from an area by entering the appropriate area coordinates.

In this paper, upgrades to the POWER data portal and the merits of the resulting solar and meteorological data will be described and assessed.  Upgrades to the POWER data portal have been implemented to provide solar and meteorological data on a ½-degree global grid with Geographic Information System (GIS) capabilities for data visualization and delivery of data via open geospatial consortium (OGC) compliant web mapping services. The solar data in the upgraded POWER portal continues to be taken from The NASA/GEWEX Surface Radiation Budget (SRB) and Clouds and the Earth’s Radiant Energy System (CERES)/Fast Longwave and SHortwave radiative Fluxes (FLASHFlux) projects re-gridded to ½-degree. Meteorological parameters now are taken from the NASA Modern Era Retrospective-analysis for Research and Applications (MERRA) data set which provides higher resolution data products (hourly and 1/2 x 1/2 degree) covering the entire globe. More than 30 years daily time slices are included in the combined solar and meteorological data sets with the solar data spanning the time period from July 1983 to within about 1-week of current time and the meteorological data spanning the time period from January 1981 to within several days of current time.

The assessment of both the meteorological and the solar irradiance data are based upon comparisons with globally distributed surface observations – the meteorological observations from the National Climate Data Center’s “Global Summary of the Day” (GSOD) data files and solar data from NASA’s Baseline Solar Radiation Network (BSRN) and other high quality surface measurement networks.  Assessments of other parameters of interest such as heating, cooling, and growing degree-days are based upon MERRA vs. surface observations taken from the GSOD files.  Results from the uncertainty assessments demonstrates that the NASA’s meteorological and solar irradiance data can represent a viable alternative to surface observations, particularly in data sparse regions of the world.