Development of a 30-Year Soil Moisture Climatology for Situational Awareness and Public Health Applications

The NASA Short-term Prediction Research and Transition (SPoRT) Center has been running a real-time configuration of the Noah land surface model (LSM) within the NASA Land Information System (LIS) framework. The LIS-Noah is run at 0.03-degree resolution for local numerical weather prediction (NWP) and situational awareness applications at NOAA National Weather Service (NWS) forecast offices over the southern and eastern Continental U.S. (CONUS). To enhance the practicality of the LIS-Noah output for drought monitoring and assessing flood potential, a 30-year soil moisture climatology is being developed over the full CONUS to place near real-time soil moisture values in historical context. The 0.03-degree LIS-Noah climatology is intended to help capture county- and watershed-scale soil moisture heterogeneity, thereby providing a higher-resolution complement to the current North American Land Data Assimilation System phase 2 (NLDAS-2) products, which are generated on a coarser 0.125-degree grid. Additionally, the soil moisture climatology and subsequent near real-time anomalies will be applied to the Center for Disease Control's (CDC) National Environmental Public Health Tracking Network to help monitor soil conditions favoring the development of certain vector-borne illnesses such as Valley Fever.

To construct the soil moisture climatology, LIS-Noah is configured for a 32+ year run, with the first two years used as a model spin-up. The climatology run is driven by NLDAS-2 forcing data and uses a new 30-arcsecond green vegetation fraction (GVF) monthly climatology found in version 3.5+ of the community Weather Research and Forecasting model, derived from fraction of photosynthetically active radiation data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The LIS-Noah spin-up occurs from 1979-1980, with the soil moisture climatology spanning 1 January 1981 to 31 December 2010, consistent with the official National Climate Data Center's most recent 30-year climate averages. LIS-Noah fields are output once daily at 0000 UTC on the CONUS grid, and soil moisture histogram climatologies are then developed on a county-by-county basis for each day of the year. The LIS-Noah simulation is extended to near real-time using the same NLDAS-2 forcing, but with real-time MODIS GVF data. The daily soil moisture histograms will then be used to identify the real-time soil moisture percentiles at each grid point according to the county in which the grid point resides. Output will be compared to similar NLDAS-2 products at http://www.emc.ncep.noaa.gov/mmb/nldas/drought/, with soil moisture validated against in situ observations as found in Texas A&M's North American Soil Moisture Database. This presentation will highlight preliminary results from the 30-year LIS-Noah soil moisture climatology and present proposed applications at partnering NOAA/NWS forecast offices and in the CDC Public Health Tracking Network.