65th IHC Booklet/Program (pdf - 4.9MB) - Office of the Federal ...

Improved Hurricane-force Surface Winds and Rain Rate Retrievals
with the Step Frequency Microwave Radiometer
J Carswell 1 , P. Chang 2 , Z. Jelenak 2 and S. Frasier 3
(carswell@remotesensingsolutions.com)
1 Remote Sensing Solutions, 2 NOAA/NESDIS/STAR, 3 University of Massachusetts
With the operational deployment of the Stepped Frequency Microwave Radiometer (SFMR),
hurricane reconnaissance and research aircraft provide near real-time observations of the 10-m
ocean surface wind speed both within and around tropical storms and cyclones. These data are
used by hurricane specialists to assist in determining wind radii and maximum sustained winds -
critical parameters for determining and issuing watches and warnings. These observations are
also used for post storm analysis, model validation, and even ground truth for future satellitebased
wind sensors. It is therefore imperative that any errors in these observations be understood
and reduced as much as possible.
In previous studies, SFMR rain retrievals have been shown to exhibit a bias of 5 mm/hr and to
under report the rain rate, suggesting that the SFMR rain absorption model requires
improvement. To address this, we present further studies documenting the problem, as well as a
new rain absorption model. Using this new model in the SFMR retrieval process, significant
improvements in both the wind speed and rain rate retrievals are achieved.
Poster Session – Page 3