Drivers of Coastal United States Relative Sea-Level Trends During the Satellite Altimeter-Era

Abstract:

Regional relative sea-level change is influenced by multiple physical processes that vary both in space and time, and which lead to large regional departures from the long-term rate of global mean sea-level rise. Identifying the different processes contributing to sea-level change at a particular location is important from a planning perspective, as understanding the drivers of local sea-level change could lead to improved projections and decision making. The modern sea-level observing network along with recent advances in process-based understanding of sea-level variability offer the opportunity to quantify contributions from the leading drivers of regional sea-level trends. In this study, relative sea-level trends from 1993 to 2019 observed by tide gauges and satellite altimeters along the Pacific, Atlantic, and Gulf of Mexico coastlines of the U.S. are interpreted in terms of water mass redistribution, sterodynamic variability, and vertical land motion. With closure of the relative sea-level budget in 41 of 49 locations within bounds of uncertainty, results from this work demonstrate the efficacy of the modern sea level observing network and highlight limitations in estimating the influence of vertical land motion and sterodynamic variability on sea-level trends.