Interannual Sea Level Variability Along the U.S. East Coast During Satellite Altimetry Era: Local versus Remote Forcing
Event: 2023 Ocean Surface Topography Science Team Meeting
Session: Science II: Large Scale Ocean Circulation Variability and Change
Presentation type: Type Oral
Contribution: PDF file
The contributions of local and remote forcings to the interannual sea level anomalies (SLAs) along the U.S. east coast (USEC) during the satellite altimetry era from 1993-2019 are quantified with analytical models assisted by statistical method. The local forcings from alongshore wind stress, sea level pressure via inverted barometer (IB) effect, and river discharges together explain 47%, 60.4% and 66.8% of coastal sea level variance in the South Atlantic Bight (SAB), Mid-Atlantic Bight (MAB) and Gulf of Maine (GOM), respectively, with river discharges having the minimum contribution. The remote forcings associated with open-ocean signals from the east and from the northern boundary at the Scotian coast together with the Gulf Stream (GS) variability explain 45.7%, 28.5% and 37.7% of coastal sea level variance in the SAB, MAB and GOM, respectively, playing a comparable role as local forcings in the SAB. The open-ocean sea level signals from 35°N-38°N strongly influence coastal SLAs in the SAB. The coastal SLAs in the SAB are also affected by the upstream GS strength (28°-36°N) and by basin-scale wind stress curl anomaly, which is linked to the meridional shift in the downstream GS (74°-68°W). Remote forcings from the subpolar North Atlantic and wind stress curl from the Grand Banks to the Scotian coast influence coastal SLAs in the GOM and MAB via the northern boundary of the USEC at the Scotian coast.