Advisor: Ron Smith
Tropical cyclones often undergo rapid and unpredicted changes in intensity that surprise forecasters and the public alike. For example, Hurricane Wilma strengthened from a tropical storm to a category 5 hurricane in one day! Often rapid intensifications can be linked to one of three causes: positive ocean feedback, storm restructuring, or removal of an external hindrance. In the cases of Hurricanes Katrina and Rita, both systems crossed over the same warm-core ocean ring in the Gulf of Mexico which provided a sudden burst of energy to the hurricanes. Hurricane Charley, however, is an example of a storm that underwent rapid intensification due to a reorganization of the eyewall after passing over Cuba. I hope to use remote sensing information to create a climatology of rapid fluctuations, especially increases, in hurricane intensity.
Sea-surface temperatures from AVHRR data will provide me with a good indications at to the sea's ability to support fast-moving tropical cyclones. Sea-height data will provide an insight into the depth of the warm water and associated heat potential. Passive and active microwave imagery can also be used to examine storm structure. Analysis of 37 GHz imagery shows liquid water droplet concentration whereas 85 GHz imagery shows upper-level ice crystals. By examining the polarization at these frequencies, convective bands and eyewalls can clearly be seen. When storms approach land, ground based radars become an essential tool. Using reflectivity and Doppler velocity scans, banding and storm structure can easily be examined.