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Modeling & Data Assimilation Projects
MODIS SST/MIA project
An experiment to test the impact of MODIS SSTs on short-term forecasts is underway with the Miami WFO. WRF forecasts, using the identical model configuration as those produced operationally at Miami, will be both verified against surface observations and subjectively compared.
AIRS Radiance Assimilation
Recently, SPoRT has begun to investigate radiance assimilation within the regional modeling framework. SPoRT, in cooperation with the NASA/NOAA/DoD JCSDA and NCEP/EMC, has begun to utilize the Gridpoint Statistical Interpolation (GSI) 3D-VAR analysis system, which is used operationally by NCEP for the NAM data assimilation system and will shortly be the operational GFS data assimilation system. This system, as well as access to NCEP resources, has allowed for the ability to reproduce an operational run-time environment. The GSI system is a sophisticated 3D-VAR scheme supported by NASA and NOAA. This united effort allows for the accelerated transition of improvements among agencies.
AIRS Profile Assimilation
The SPoRT center seeks to improve short-term weather forecast, especially in the data-sparse region, by the use of satellite-based observations. The Atmospheric InfraRed Sounder (AIRS), aboard the EOS polar-orbiting Aqua satellite, provides near-rawinsonde-quality atmospheric temperature profiles with the ability to resolve some small-scale vertical features. The SPoRT forecast/assimilation system consists of the Weather Research and Forecasting (WRF) model and ARPS Data Assimilation System (ADAS). The forecast/assimilation cycle starts at 00 UTC and runs several hours until the AIRS overpass time is reached (usually around 07-09Z for the morning pass). The WRF forecast is then used as the background field for ADAS to assimilate AIRS data.
Land-Atmosphere Interactions
SPoRT is conducting land-atmosphere interaction experiments using a version of the Weather Research and Forecasting (WRF) model coupled to the NASA Land Information System (LIS) software. The LIS is a tool that can run a variety of land surface models in isolation, or coupled to the WRF model in order to optimize land and soil states for regional to global modeling applications. SPoRT’s goal is to develop an optimized configuration of LIS/WRF for regional short-term forecasting, and quantify any improvements that may result from running LIS in conjunction with WRF.
Lightning Threat
Research into lightning forecasting at SPoRT has relied on recent global observational findings from the TRMM-LIS satellite platform that show strong correlations between storm flash rates and other storm characteristics, such as the amount of large precipitating ice lofted by updrafts above the -15C level, and the shape of the reflectivity profile. Aware of these findings, SPoRT researchers have performed high-resolution (2-km) simulations of a number of North Alabama storm cases using the WRF model, and have generated model-derived time- and space-dependent proxy fields expected to be proportional to total storm flash rate.
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