Understanding Regional Sea Level Rise Acceleration Along the North American Eastern Seaboard

Sea level rise continues to be one of the most costly and complex consequences of global warming in the recent decades. The East Coast of the United States has experienced higher rates of sea level rise acceleration compared to the global average, leading to increased coastal flooding in this region. Building on previous studies of North Atlantic Ocean climate variability, we investigate subtropical North Atlantic oceanic and atmospehric influences on East Coast sea level. Regression anlaysis between NOAA tide gauge sea surface height measurements and multiple reanlaysis products reveal a consistent positive sea surface height trend in recent decades, however the magnitude and spatial distribution of the trends vary across datasets. The Gulf Stream's influence on hot spots of sea level rise along the East Coast, which has been previously documented, was also investigated. Discrepancies in the magnitude of Gulf Stream strength and position between observational and reanalysis products was also shown raising questions about the role of basin-wide and local wind forcing in modulating the Gulf Stream strength, position, and coastal sea level. To explore this, we apply anomalous wind stress forcing in the Community Earth System Model Version 1 (CESM1) demonstrating that local winds significantly impact sea surface height in both the south Atlantic Bight (Key West, FL to Cape Hatteras, NC) and Mid-Atlantic Bight (Cape Hatteras, NC to Cape Cod, MA). With future projections of oceanic and atmospheric warming due to anthropogenic CO₂ emissions, these findings highlight the need for improved representation of steric height trends, mass flux, and GS variabliity in reanlaysis datasets. Additionally, the importance of evolving atmospheric circulation dirving hot spots of sea level rise in conjunction with thermohaline and steric contributions.