Two SPoRT datasets are available to initialize model runs in version 3.1 of the Weather Research and Forecasting Environmental Modeling System (WRF EMS):
(1) SPoRT’s enhanced Sea Surface Temperature (SST) composites, and
(2) a 3-km version of the NASA Land Information System (LIS) over the Southeastern U.S.
The enhanced SST product for model initialization features the full 1-km resolution SST grid in GRIB-2 format with reduced latency over the MODIS-only SSTs due to the inclusion of microwave SST data from AMSR-E. The enhanced SSTs also contain a special analysis over the Great Lakes, which includes a built-in ice-masking by setting SSTs to 270K at ice points. The product covers much of North and Central America on a 9000 x 6000 domain (Figure 1). As with the MODIS-only SSTs, the composites are generated 4 times per day at 0400, 0700, 1600, and 1900 UTC. To use the SPoRT SSTs in the WRF EMS v3.1, simply select “SFC = sportsst” in the ems_autorun.conf file. SPoRT also recommends setting “BESTHR = sstsport” to use the SST composite that most closely matches in time the model initialization hour. For a backup capability, one could also set “SFC = sportsst,ssthr” to give highest priority to the sportsst, but also use ssthr as a backup in case the sportsst data are not available.
The LIS land surface model (LSM) option is advantageous to initialize land surface fields at a representative high-resolution for local model runs. Instead of interpolating coarser resolution, less representative soil moisture/temperature/etc. from a large-scale model, the LIS output provides 3-km resolution land surface fields from the Noah LSM to initialize the WRF EMS over Southeastern U.S. domains (sample soil moisture field shown on the current LIS domain in Figure 2). The use of high-resolution LIS initialization data has been shown to improve the WRF predictions of 2-m temperatures and sea breezes (Case et al. 2008; Weather and Forecasting) and explicit summer convective precipitation over the Southeastern U.S. (Case et al. 2009, 2010). To use the LIS fields for initializing the WRF EMS v3.1, simply set “LSM = lis” in the ems_autorun.conf file. Similarly, a backup LSM dataset could be used in the event that the LIS data are missing (e.g. “LSM = lis,namptile” in ems_autorun.conf). SPoRT plans to expand the current 3-km LIS domain in the near future to cover a larger portion of the Continental U.S.