On the key influence of remote climate variability from Tropical Cyclones, North and South Atlantic mid-latitude storms on the Senegalese coast (West Africa)

Abstract

The low-lying Senegalese sandy coast is extremely vulnerable to marine flooding and erosion. Using climate and wave reanalysis, we establish the remote connections between Atlantic climate modes and coastal wave variability in Senegal. We show that impacting swells come from the North Atlantic in boreal winter but also from the South and Tropical Atlantic in boreal summer. Near shore-normal tropical cyclones swells have a large impact on the sea level contribution at the coast but a limited influence on the longshore sediment transport. In contrast, boreal summer south swells have a large destabilizing coastal impact due to a reversal of the climatological southward sediment drift. They also induce large sea level anomalies on the southern Senegalese coast, the most exposed to flooding. This study emphasizes the importance of quantifying the influence of both the regional and remote climate variability on wave activity to better understand the drivers of coastal evolution and vulnerability.