Validation of Global LDAS Radiative Forcing
Jesse Meng, Paul Houser, Kenneth Mitchell, Matt Rodell, Jon Gottschalck, Urszula Jambor, Kristi Arsenault, Michael Bosilovich, Brian Cosgrove, Jared Entin, Jon Radakovich, Jeffrey Walker, Hua-Lu Pan and George Gayno,
In order to improve our understanding of the space-time structure of the land-atmosphere interaction on a global scale, a high-resolution, near-real-time, Global Land Data Assimilation System (GLDAS) has been developed at NASA's Goddard Space Flight Center and NOAA NCEP. GLDAS is running operationally on a daily basis, using the NOAA/NCEP/GDAS and NASA/DAO/GEOS global analysis as the baseline atmospheric conditions. Radiation and precipitation derived from satellite and in-situ observations are introduced to the system to provide accurate land surface forcing. The Air Force Weather Agency's RTNEPH realtime global cloud analysis is implemented to generate a more realistic surface radiative fluxes. In this paper we evaluate all the options of radiative forcing used in GLDAS. The accuracy, difference, and potential consequent impacts to land surface models will be studied. Ground observations from the SURFRAD and ARM sites, and GOES satellite estimates will be used. The analysis will be made on various temporal scales, from diurnal cycles to monthly averages.