Global Land Data Assimilation System
North American (NLDAS) and Global (GLDAS) LDAS systems are being developed that will lead to 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. NLDAS is currently running retrospectively and in near real-time on a 1/8th-degree grid while GLDAS is running at 1/4 degree resolution. The systems are currently forced by terrestrial (NLDAS) and space based (GLDAS) precipitation data, space-based radiation data and numerical model output. In order to create an optimal scheme, the projects involve several LSMs, many sources of data, and several institutions. Data from the project can be accessed on the NLDAS and GLDAS forcing pages, the NLDAS and GLDAS model output pages, as well as on the NLDAS Realtime Image Generator page.
Summary Provided By: http://ldas.gsfc.nasa.gov/