2.5
Assimilation of MODIS temperature and water vapor profiles into a mesoscale analysis system
Bradley T. Zavodsky, Florida Institute of Technology, Melbourne, FL; and S. M. Lazarus, P. F. Blottman, and D. W. Sharp
The Florida peninsula is unique in that the domain over which the coupled Advanced Regional Prediction System (ARPS) and its analysis component, the ARPS Data Analysis System (ADAS), are run (at the Melbourne NWS) is dominated by the Atlantic and Gulf of Mexico. The dearth of over ocean observations is apparent over the extended domain east of the peninsula where there are just two buoys in the open water east of the Kennedy Space Center, the siting of a relatively new buoy (June 2002, #41012) east of St. Augustine, and some along-shore C-MAN buoys in the Florida Keys and one on the western tip of Grand Bahama Island. Hence, the mesoscale analyses while populated by land surface observations (which modify the analysis first guess field obtained from the RUC), have little in the way of 'over ocean' data. Because of this, the analyses converge toward the background or first-guess field off-shore. This is potentially problematic, especially during the summer months when the magnitude and depth of the easterly flow determines the extent to which the sea breeze penetrates inland and subsequently impacts the convective cycle. Additionally, cool season (Fall) precipitation along the east coast of Florida (often referred to as coastal showers), ostensibly driven by fluxes of heat and moisture associated with strong low-level easterly flow, remains a forecast challenge.
We present results for which the ADAS is configured to ingest satellite observations of temperature and moisture from the relatively new MODerate resolution Imaging Spectrometer (MODIS) Atmospheric Profile Level 2 products retrieved from instruments on board the Terra and Aqua satellites. The profiles are produced day and night for Level 2 at 5×5 1-km pixel resolution when at least 9 FOVs are cloud free. The MODIS temperature and moisture profiles are produced at 20 vertical levels - providing atmospheric column data over ocean regions that are otherwise sparsely populated by observations. We examine the spatial correlation characteristics of the satellite swaths within the Florida ADAS domain, compare the retrieved profiles with the 20 km Rapid Update Cycle (i.e. the ADAS background field), and evaluate the retrieved profiles by comparing against available synchronous upper air data at Key West, Tampa, Kennedy Space Center, Miami, and Jacksonville.
Session 2, Analysis Techniques (ROOM 605/606)
Monday, 12 January 2004, 10:45 AM-12:00 PM, Room 605/606
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