LIS runs are driven by atmospheric forcing data. LIS uses two atmospheric data assimilation model outputs as the base forcing: one is the NCEP GDAS (Global Data Assimilation System) output, and the other is the NASA GEOS DAS output. The model forcing data are then superposed by optional observed datasets such as radiation and precipitation. Detailed information about these datasets and the links to access the data are shown in the table below.

Dataset	Description	Original Source	Processing Info
GDAS	The Global Data Assimilation System (GDAS) is the global operational weather forecast model of NCEP (Derber, et al, 1991).	NCEP	GLDAS
GEOS	Obtained from GSFC's Goddard Earth Observing System Data Assimilation System (GEOS).	NASA GMAO
AGRMET shortwave flux	LDAS estimates global, downward shortwave, and longwave radiation fluxes using a procedure from the Air Force Weather Agency's (AFWA) Agricultural Meterology modeling system (AGRMET).	AFWA AGRMET
AGRMET longwave flux
CMAP Precipitation	The Climate Prediction Center Merged Analysis Precipitation is a technique which produces pentad and monthly analyses of global precipitation.	Climate Prediction Center
EDAS	The NCEP ETA Data Assimilation System	NCEP
ECMWF	The European Centre for Medium-Range Weather Forecasts	ECMWF