The 23rd Conference on Hurricanes and Tropical Meteorology

P7B.2
THE UW-CIMSS OBJECTIVE DVORAK TECHNIQUE (ODT)

Timothy Olander, CIMSS/University of Wisconsin, Madison, WI; and C. Velden

An experimental algorithm has been developed at UW-CIMSS to objectively determine tropical cyclone intensity utilizing infrared geostationary satellite data. The Objective Dvorak Technique (ODT) is based on earlier work by Dvorak and Zehr but has incorporated many new statistically-based routines, such as Fourier Transform and histogram analysis, to classify eye and surrounding cloud region properties. Selected "Dvorak Rules", scene identification, and time averaging schemes have also been integrated, significantly reducing many previously observed errors and biases. Statistical analysis of twelve Atlantic hurricanes between 1995 and 1997, compared with coincident aircraft reconnaissance pressure observations, resulted in an overall bias and RMSE less than 0.5 and 7.5 millibars, respectively.

Independent analysis of the ODT was performed by the Satellite Analysis Branch (SAB) of NOAA/NESDIS during the 1997 North Atlantic hurricane season, with continued analysis by SAB and the Tropical Prediction Center during the 1998 season. This presentation will summarize the ODT performance and outline future directions of study. Such areas will include the utilization of further statistical techniques such as EOF/PCA analysis, automated storm center determination, multispectral techniques, and application of the ODT to tropical cyclones outside of the North Atlantic

The 23rd Conference on Hurricanes and Tropical Meteorology