Interannual Sea Level Variability Along the Southeastern Seaboard of the United States in Relation to the Gyre-Scale Heat Divergence in the North Atlantic

The low-amplitude, large-scale, interannual, and longer-term sea level changes are linked to the variations of ocean heat and freshwater content and strongly controlled by ocean dynamics. Near the coast, especially in low-lying and flood-vulnerable regions, these changes can provide background conditions favorable for the occurrence of extreme sea levels that represent a threat for coastal communities and ecosystems. In this study, we identify a tripole mode of the ocean gyre-scale sea surface height variability in the North Atlantic and show that this mode is responsible for most of the interannual-to-decadal sea surface height changes along the southeast coast of the United States, including the Gulf of Mexico. We also show that these changes are largely driven by the large-scale heat divergence related to the Atlantic Meridional Overturning Circulation and linked to the low-frequency North Atlantic Oscillation.