Master’s Defense – Sherry Young

Candidate: Sherry Young

Master of Science in Earth Systems Sciences 

Department of Geography and Geoinformation Science

Date:   Monday, April 29th, 2019

Time:   1:30 – 4:15 PM

Place:  Research Hall 161

 

TITLE: POSSIBLE EFFECTS OF THE LOOP CURRENT ON INTENSITY AND RAPID INTENSIFICATION OF HURRICANES IN THE GULF OF MEXICO

Committee:

Thesis Director: Dr. Randy McBride

Committee Members: Dr. Barry Klinger and Dr. Celso Ferreira

ABSTRACT

Increasing population in coastal communities is putting more lives and property at risk from hurricanes. A great need exists for a better understanding of hurricane intensity and rapid intensification; especially if frequency and intensity could increase because of warming oceans. Eleven Gulf of Mexico hurricanes and their fluctuations in intensity relative to proximity to the Loop Current, ocean heat content, depth to the 26°C isotherm, and SST were investigated. ESRI ArcMap was utilized to map and relate hurricane and ocean surface layer data obtained by satellite, reanalysis products, and NHC observations. 164 data points were binned to sort by proximity to the Loop Current and to isolate other factors such as eyewall replacement cycles and wind shear. Linear regression was used to calculate correlations between variables and intensity, percent of maximum potential intensity (MPI), and to calculate probability of rapid intensification. Katrina had the best correlation between sustained wind speed and ocean heat content at 91% during rapid intensification episodes. During favorable conditions, data points with the highest sustained wind speeds of 250 km/hr or more and that reached 100% of MPI occurred where SST was 29.75°C or greater, depth to the 26°C isotherm was 50 m or more, and TCHP was 90 kJ/cm² or more. During favorable conditions hurricanes were more likely to rapidly intensify at 57.1% over the LC than GCW at 40%. Results suggest that increased ocean heat content and depth to the 26°C isotherm in the Loop Current limits surface cooling due to mixing permitting additional intensification during favorable conditions.