……

Abstract

In this study, a climatology analysis of the cyclonic activity in the North Atlantic (NATL) basin was performed to improve our understanding of how sea surface temperature (SST) and climate variability modes modulate tropical cyclones (TCs) activity. The information on the TCs was extracted from the International Best Track Archive for Climate Stewardship database, while the SST was obtained from the Centennial Time Scale dataset. The SST analysis reveals a warming trend of approximately 0.23 °C/decade for the NATL basin during the TC season between 1980 and 2019, while the TC activity shows an increase of ~1.4 TC/decade in the number of TCs that reach the tropical storm category. Nevertheless, the observed increase in the frequency of hurricanes is not significant. The increasing frequency of TCs after 2000 concerning the 1980-1999 period was probably caused by increasing favourable conditions for cyclonic development, such as positive SST anomalies. Moreover, the eastern regions of the NATL basin exhibit an increase in storm track density, which explains the observed decrease in track density near the Lesser Antilles Arc. In addition, the Atlantic meridional mode, the Atlantic multidecadal oscillation, and El Niño-Southern Oscillation have a significant influence on the TCs activity; however, they cannot fully explain the tendency to increase the TCs frequency in the last decades.

Keywords: tropical cyclones activity; climate variability modes; sea surface temperature