A satellite approach for estimating regional land surface energy budget for GCIP/GAPP

Abstract

Conventional observations cannot provide information on land surface energy fluxes, or information for land surface parameterizations, on a global or regional scale. In this paper, a satellite approach for estimating regional land surface energy budget is developed and implemented to the Mississippi River Basin, which serves as the focus of the World Climate Research Program Global Energy and Water cycles Experiment (GEWEX) Continental Scale International Project (GCIP) and GEWEX Americas Prediction Project (GAPP). The objective of this study is to evaluate the potential of using recently available satellite information to advance current capabilities in determining regional land surface energy budget. The primary forcing parameters in this approach, namely, surface shortwave radiation and skin temperature, are derived from the Geostationary Operational Environmental Satellite (GOES) observations, using inference schemes that are operationally executed at the National Oceanic and Atmospheric Administration National Environmental Satellite Data and Information Service (NESDIS). Shortwave radiation is used to define the absorbed energy at the surface. Diurnal variation of skin temperature is used to define the surface energy partitioning. The real‐time NESDIS GOES product covers the continental United States (25°–53°N, 67°–125°W), at a 0.5° spatial resolution and an hourly temporal resolution. Atmospheric conditions of near‐surface air temperature, humidity, and wind speed are obtained from the NOAA National Centers for Environmental Prediction (NCEP) Eta model output. A 1‐year simulation (May 1997 to May 1998) of the Mississippi River Basin surface energy budget is performed. Model inputs of shortwave radiation and skin temperature, and resulting latent and sensible heat fluxes, are evaluated on various spatial and temporal scales. On a local scale, over the 1‐year study period, the RMS difference between estimated and observed monthly shortwave fluxes and latent and sensible heat fluxes are 32, 21, and 20 Wm−2, respectively. On a regional scale the estimated summertime energy fluxes are of similar pattern and same order of magnitude as the corresponding reanalysis results from NCEP and National Center for Atmospheric Research.