What are the differences among LDAS, NLDAS, and GLDAS?
The Land Data Assimilation Systems (LDAS) are being developed to enable more accurate reanalysis and forecast simulations by numerical weather prediction (NWP) models. Specifically, these systems will reduce the errors in the stores of soil moisture and energy which are often present in NWP models and which degrade the accuracy of forecasts. The LDAS are being implemented at 1/8 degree (about 15 kilometer) resolution across North America (NLDAS) and at 1/4 degree resolution globally (GLDAS). The systems are currently forced by terrestrial (NLDAS) and space-based (GLDAS) precipitation data, space-based radiation data, and numerical model output. NLDAS is currently running retrospectively and in near real-time. For more information about LDAS, see http://ldas.gsfc.nasa.gov.
