Publication Date:
2022-05-25
Description:
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Proceedings of the National Academy of Sciences.of the United States of America 115 (2018): 7729-7734, doi:10.1073/pnas.1805428115.
Description:
Identifying physical processes responsible for historical coastal sea-level changes is important for anticipating future impacts. Recent studies sought to understand the drivers of interannual to multidecadal sea-level changes on the United States Atlantic and Gulf coasts. Ocean dynamics, terrestrial water storage, vertical land motion, and melting of land ice were highlighted as important mechanisms of sea-level change along this densely populated coast on these time scales. While known to exert an important control on coastal ocean circulation, variable river discharge has been absent from recent discussions of drivers of sea-level change. We update calculations from the 1970s, comparing annual river-discharge and coastal sea-level data along the Gulf of Maine, Mid-Atlantic Bight, South Atlantic Bight, and Gulf of Mexico during 1910–2017. We show that river-discharge and sea-level changes are significantly correlated (p〈0.01), such that sea level rises between 0.01 and 0.08 cm for a 1 km3 annual river-discharge increase, depending on region. We formulate a theory that describes the relation between river-discharge and halosteric sea-level changes (i.e., changes in sea level related to salinity) as a function of river discharge, Earth’s rotation, and density stratification. This theory correctly predicts the order of observed increment sea-level change per unit river-discharge anomaly, suggesting a causal relation. Our results have implications for remote sensing, climate modeling, interpreting Common Era proxy sea-level reconstructions, and projecting coastal flood risk.
Description:
C.G.P. and R.M.P. acknowledge support from NASA Contract NNH16CT01C (which also supported C.M.L.), NASA Jet Propulsion Laboratory Subcontract 1569246, and National Science Foundation Award 1558966. C.G.P. also acknowledges support from The Investment in Science Fund at Woods Hole Oceanographic Institution. A.C.K. and S.E.E. acknowledge NSF Awards OCE-1458921 and OCE-1458903, respectively.
Keywords:
Coastal sea level
;
Coastal river plumes
;
Coastal flood risk
;
Climate modeling
;
Physical oceanography
Repository Name:
Woods Hole Open Access Server
Type:
Article
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