Tropical Cyclone Intensity Estimation Using the NOAA-KLM Series advanced microwave sounding unit (AMSU):Preliminary Results and future prospects

Satellite-based analysis and monitoring of Tropical Cyclones (TC) recently entered its second decade with the development and launch of the NOAA-15 Advanced Microwave Sounding Unit (AMSU) on May 13, 1998. The AMSU offers an unprecedented opportunity to characterize TC thermodynamic structure by virtue of its combined atmospheric temperature/moisture sounding capabilities (previous-generation Microwave Sounding Unit (MSU) only measured temperature), improved horizontal resolution (48km vs. 110km at nadir respectively), and relative insensitvity to clouds near 55GHz. Preliminary 1998/1999 results (108 cases) demonstrate moderate correlation between AMSU-A limb-corrected upper tropospheric brightness temperatures (AMSU-A Channels 7 (54.94GHz) and 8 (53.3GHz)) to storm-related mean sea level pressure (MSLP). More importantly, the results suggest that storm position/AMSU scan geometry issues (Merrill, 1995) must be resolved prior to development of a regression-based scheme relating AMSU-A thermal anomalies to MSLP. Several topics will be discussed including AMSU preliminary results from the 1998/1999 TC seasons, NOAA-15 AMSU vs. NOAA-14 MSU comparisons, as well as a preview of future work including the development of 1) a precipitation/scan geometry/antenna corrected temperature retrieval algorithm, 2) a TC intensity estimation scheme, and 3) near-real time, web-based AMSU resources.