The North American Land Data Assimilation System Phase 2 (NLDAS-2) 0.125o
hourly Noah model data (NLDAS_NOAH0125_H.002) are accessible via the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) Hydrology Data Holdings
page. The data set contains a series of land surface parameters and has temporal coverage from 01Z January 02, 1979 to present, with latency about four days. More information about the data set can be found in the NLDAS-2 README document
NLDAS, with high spatial and temporal resolutions (0.125° x 0.125° hourly) and various water- and energy-related variables (precipitation, soil moisture, evapotranspiration, heat fluxes, etc.) is an excellent data source for supporting water and energy cycle investigations.
Figures 1–4 below show example NLDAS data as displayed via the Giovanni NLDAS hourly portal, for studying the effects of 2011's Tropical Storm Lee and model inter-comparison. The unit kg/m2 is equivalent to mm/hour.
Figure 1. NLDAS-2 Noah rainfall, averaged over the time period of 08Z September 2 -12Z September 9, 2011, showing heavy rain brought by Tropical Storm Lee.
Figure 2. NLDAS-2 Noah layer 1(0-10 cm) soil moisture, averaged over the time period of 08Z September 2 -12Z September 9, 2011. The high soil moisture regions coincide with the heavy rain regions in Figure 1.
Figure 3. Time series (08Z September 2 – 12Z September 12, 2011) of NLDAS-2 Noah hourly rainfall (blue line) and layer 1 (0-10 cm) soil moisture (red line) for a heavy rain region (77W ~ 75W, 39N ~ 42N, corresponding to a region in Pennsylvania). The time series show high soil moisture peaks corresponding with rainfall peaks, with the characteristic slight time lags.
Figure 4. Time series (08Z Sep. 2 – 12Z Sep. 12, 2011) of NLDAS-2 hourly layer 1 (0-10 cm) soil moisture inter-comparison, red line for Noah model data and black line for Mosaic model data, for Tropical Storm Lee heavy rain region (77W ~ 75W, 39N ~ 42N, corresponding to a region of Pennsylvania).
NLDAS is a collaborative effort of NOAA, NASA, Princeton University, the University of Washington, and others.
The GES DISC is a NASA earth science data center, part of the NASA Earth Science Data and Information System (ESDIS) Project.
Questions or comments? Email the NASA GES DISC Help Desk, email@example.com