Changes in the impact of Tropical Basin Interactions on Cape Vert tropical cyclogenesis

Abstract The interannual variability of tropical Atlantic cyclones (TCs) has been linked to ENSO and the Atlantic Meridional Mode. Recent studies have also highlighted the role of the equatorial Atlantic in influencing Cape Verde TCs. However, the stationarity of these teleconnections has not yet been thoroughly examined. In this work, running correlations between the anomalous frequency of TCs originating in the Cape Verde region and tropical sea surface temperatures (SSTs), reveal a shift in recent decades. Although the overall frequency of Atlantic TCs has increased since the 2000s, changes in atmospheric and oceanic background conditions have weakened the influence of SSTs on Cape Verde TCs. Furthermore, our assessment of eddy kinetic energy as an indicator of East African wave activity suggests that, in the context of global warming, the predictive power of sea surface temperatures may be diminished. Tropical Atlantic cyclones (TCs) are a source of public hazards causing thousands of victims and considerable damages in the West African Coast, the United States and the Caribbean. Cyclone forecasting is thus essential for mitigating the impacts on populations directly exposed to hurricane landfalls, as well as for those in regions, like Senegal, where indirect impacts such as coastal flooding