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

Estimating Tropical Cyclone Intensity from Infrared Image Data
Elizabeth A. Ritchie 1 , Miguel F. Piñeros 2 , J. Scott Tyo 2 , and Genevieve Valliere-Kelley 1
(ritchie@atmo.arizona.edu)
1 Department of Atmospheric Sciences, University of Arizona; 2 College of Optical Sciences,
University of Arizona
A near real-time objective technique for obtaining features associated with the shape and the
dynamics of cloud structures embedded in tropical cyclones from satellite infrared images is
described. As the tropical cyclone develops from an unstructured cloud cluster and intensifies
the cloud structures become more axisymmetric about an identified reference point. Using
variables derived from remotely-sensed IR data, the technique calculates the gradient of the
brightness temperatures to measure the level of symmetry of each structure and this level of
symmetry characterizes the degree of cloud organization of the tropical cyclone. Previous results
have shown that the technique provides a reasonable objective, independent measure of the
intensity of the tropical cyclone.
In this presentation, seventy-eight tropical cyclones from the 2004-2009 seasons are used to both
train and independently test the intensity estimation technique. Two independent tests are
performed to test the ability of the technique to accurately estimate tropical cyclone intensity.
Results from these tests will be presented.
Session 10 – Page 4