The impact of dynamic tropography on the intensification of hurricanes
Remko Scharroo(1) , Walter Smith(2) , and John Lillibridge(2)
330a Parsonage Road,
Cornish, NH 03745,
(2) NOAA/NESDIS, 1335 East-west Highway, Silver Spring, MD 20910, United States
Satellite altimeter data show the intensification of wind speed and wave heights associated with the recent hurricanes Katrina and Rita that ravaged the U.S. Gulf Coast. At the same time, wind surges of up to 90 cm were observed near the coast.
The correlation between the intensification and the crossing of regions of higher dynamic topography is evident. Those regions harbour more heat in the upper layer (with a thickness of approximately 100 m) than surrounding areas and can thus release more energy to the storm.
This perception is contrary to the general agreement that hot surface waters are responsible for the intensification. We will show that the intensification has a stronger correlation with dynamic topography (and thus total heat content) than with sea surface temperature (which applies only to the very top centimeter of the ocean).
Operational satellite altimeter data are therefore a more effective tools for hurricane forecasting by indicating pools of warm water than infrared sensors.
This presentation will highlight several examples of North Atlantic hurricanes, their intensification and the correlation with sea surface temperature and sea level anomaly.