North American Land Data Assimiliation (NLDAS) Data: 30 Years of Hourly Gridded Precipitation, Surface Meteorology and Fluxes, Soil Moisture, Runoff, and Snow Cover Available at the NASA Goddard GES DISC

The North American Land Data Assimilation System (NLDAS) has produced 30-years (1979 to present in near real-time) of hourly 1/8th-degree surface meteorology and hydrology datasets over CONUS and parts of Canada and Mexico. The NLDAS project has many government and university partners involved in producing and using these datasets, many funded under the Climate Prediction Program of the Americas (CPPA). NLDAS combines observations from many different sources (rain gauges, radar, satellite, model reanalysis) to generate a surface forcing dataset, which is used to drive several different land-surface models. Hourly datasets of gridded precipitation, surface meteorology and surface fluxes, soil moisture at multiple depths, surface runoff and baseflow, and snow cover are produced and available to users. This presentation will describe NLDAS forcing and land-surface model output datasets, and provide an example or two of the many applications of NLDAS data already in use. One such application is the NLDAS Drought Monitor, which updates in near real-time using several different drought indices. All 30-plus years of hourly data are now available at the NASA Goddard Earth Science Data and Information Services Center (GES DISC). Users can access the data by searching and downloading via anonymous ftp or Mirador. Mirador, a Spanish word for a window offering an extensive view, uses keywords to find data quickly in a Google-like interface. The NLDAS data are also provided via a GrADS Data Server (GDS). GDS users can access the data and perform subsetting and analysis operations online. More advanced tools will be provided in later releases, such as spatial and parameter subsetting, data format transformation, and an online visualization and analysis tool (Giovanni). Giovanni is a Web-based application developed by the GES DISC that provides a simple and intuitive way to visualize, analyze, and access vast amounts of Earth science remote sensing data without having to download the data. This presentation will also describe the services provided by the GES DISC for users to obtain and use NLDAS datasets in their applications.