Balancing the coastal sea-level budget is currently hampered by the interplay of a variety of processes that particularly affect the quantification of sterodynamic (the combination of steric variations and ocean circulation changes) effects. Here we use a global set of tide-gauge records to determine linkages between coastal sea-level variability and open-ocean steric height changes that broadly reflect our understanding of sea-level anomaly propagation pathways at inter-annual to decadal scales. We subsequently extract their common modes of variability with multivariate models and reconstruct coastal sterodynamic sea level solely based on steric height observations from the open ocean. Our reconstruction, tested in historical Earth system models, explains up to 89% of coastal sea-level variability and provides linear trends, which are, once combined with barystatic mass changes (ice-sheets, glaciers, land water storage) and vertical land motion, in close agreement to those from tide gauge records since 1960. Evaluating the individual processes contributing to the coastal budgets further reveals a dominant role of ocean-circulation on coastal sea level over the past six decades.

Sönke Dangendorf is Assistant Professor at the Center for Coastal Physical Oceanography (CCPO) and the Department of Ocean, Earth and Atmospheric Sciences (OEAS) at Old Dominion University in Norfolk, Virginia. He has more than 10 years of professional experience with a research background in understanding the causes and impacts of global and regional sea level change and coastal engineering. He is Co-Leader of an International Team investigating the performance of different reconstruction approaches to global mean sea level from tide gauge and proxy data at the International Space Science Institute in Bern, Switzerland ( https://www.issibern.ch/teams/unifysealevel/) and member of the the expert group JWG C.4: Sea level and vertical land motion ( https://iccc.iag-aig.org/joint-work-groups/218) of the International Association of Geodesy. He was also Contributing Co-Author of the recent Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) Chapter 4.

CCPO Innovation Research Park Building I 4111 Monarch Way, 3rd Floor Old Dominion University Norfolk, VA 23508 757-683-4940