Changes to Sea Surface Temperatures and Vertical Wind Shear and their Influence on Tropical Cyclone Activity in the Caribbean and the Main Developing Region

Tropical cyclone (TC) activity in the North Atlantic has been changing during recent years. There is great debate on the role that warming climate plays with changes to hurricane activity. This work focuses on researching how changes to sea surface temperatures (SSTs) and vertical wind shear (VWS) are affecting changes in TC intensity and frequency in a warming climate in the Mid and Northern Atlantic. SSTs and VWS are essential to tropical cyclone formation and invigoration. Changes to SSTs and VWS influence storm development, subsurface warming is critical to the sudden intensification of high-impact cyclones. This work analyzes SST and VWS trends for the Caribbean, surrounding region, and the Atlantic hurricane main developing region (MDR) from 1982-2020 (SST & VWS), and storm activity from 1955-2020 is also analyzed for intensity and frequency changes over time. It is observed that storm intensity increases significantly during this period, potentially due to warming SSTs and low wind shear in the region. Annual and seasonal trends show regional SSTs in the MDR are warming annually (0.0219°C yr^-1) and per season (0.0280°C yr^-1); (0.020°C yr^-1) annually and (0.024°C yr^-1) per season for the Caribbean and surrounding area. Simultaneously, the Atlantic Warm Pool is expanding at a rate of 0.51km² per decade. Coincidently, VWS decreases during the late rainfall season at 0.0556m/s yr^-1 in the MDR and 0.0167m/s yr^-1 in the Caribbean and surrounding area. Increased upper atmospheric winds are driving VWS changes. Correlations of large-area averages do not establish substantial relationships between TC intensity, frequency, and SSTs/VWS during the LRS. Additionally, the relationship between the AMO and warming SSTs were explored, results suggest that the AMO explains a small percentage of SST variance, therefore, SST warming appears to be mostly independent of the AMO. TC changes appear to be associated with regionally warming SSTs.