An Examination of the Unique Tropical Cyclone Climatology near Hispaniola and the Factors Influencing It

• Other Authors: Sangster, Sam (author), Hart, Robert E. (Robert Edward), 1972- (professor directing thesis), Misra, Vasubandhu, 1970- (committee member), Wu, Zhaohua (committee member), Florida State University (degree granting institution), College of Arts and Sciences (degree granting college), Department of Earth, Ocean, and Atmospheric Science (degree granting department)
• Format: Master Thesis
• Language: English
• Published: Florida State University 2021
• Subjects: Meteorology; Sadler; North Atlantic
• Online Access: https://diginole.lib.fsu.edu/islandora/object/fsu%3A796857/datastream/TN/view/Examination%20of%20the%20Unique%20Tropical%20Cyclone%20Climatology%20near%20Hispaniola%20and%20the%20Factors%20Influencing%20It.jpg

Using data from the National Hurricane Center's (NHC's) Best Track archive, it is found that there are local minima and maxima of occurrence of tropical cyclone (TC) activity in the southwest North Atlantic basin where sea-surface temperatures (SSTs) are rarely an inhibiting factor for development for the majority of the TC season. One area with unique variability in frequency is near Hispaniola. This region is characterized by relatively random TC motion and unique spatial variability in TC frequency between the western and eastern parts of the region. In this study, Hispaniola's TC climatology will be investigated from a mesoscale, a synoptic dynamical, and a climate perspective. It is known that terrain has an impact to both the motion of the TCs in other regions and basins (Bender et al. 1987, Huang et al. 2011, Ito et al. 2020), but it has not been well examined for the areas adjacent to the Caribbean Islands. Using the historical data from NHC's Best Track, the effects of the terrain on TC motion are shown for Hispaniola to better understand this regional variability in TC occurrence and motion. Findings show that channeling effects, asymmetric mid-level flow, and terrain-induced blocking of environmental steering all play a role in the direction and speed of TCs approaching the southern part of the island and after landfall. Fitzpatrick et al. 1995, Sadler 1976a & 1976b, and Wang et al. 2016 have shown that the Tropical Upper Tropospheric Trough (TUTT) is present during the summer season across the western regions of each major ocean basin. Although there is considerable variability, this trough is climatologically located west of Hispaniola, putting the island in the most cyclonic region of the trough. Utilizing data from the European Centre for Medium-Range Weather Forecasts (ECMWF) 5th Generation Reanalysis (ERA-5), the effects of the TUTT on this regional variability of occurrence will be examined. Findings show that regions of enhanced TC activity are mostly located near favorable locations of TC ...