Atlantic meridional overturning circulation increases flood risk along the United States southeast coast

Denis L Volkov; Kate Zhang; William E Johns; Joshua K Willis; Will Hobbs; Marlos Goes; Hong Zhang; Dimitris Menemenlis

doi:10.1038/s41467-023-40848-z

Atlantic meridional overturning circulation increases flood risk along the United States southeast coast

Nat Commun. 2023 Aug 22;14(1):5095. doi: 10.1038/s41467-023-40848-z.

Authors

Denis L Volkov^{1

2}, Kate Zhang³, William E Johns⁴, Joshua K Willis⁵, Will Hobbs^{6

7}, Marlos Goes^{8

9}, Hong Zhang⁵, Dimitris Menemenlis⁵

Affiliations

¹ Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, USA. denis.volkov@noaa.gov.
² NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, FL, USA. denis.volkov@noaa.gov.
³ Joint Institute for Regional Earth System Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA.
⁴ Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, FL, USA.
⁵ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
⁶ Australian Research Council Centre of Excellence for Climate Extremes, Sydney, NSW, Australia.
⁷ Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia.
⁸ Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, USA.
⁹ NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, FL, USA.

Abstract

The system of oceanic flows constituting the Atlantic Meridional Overturning Circulation (AMOC) moves heat and other properties to the subpolar North Atlantic, controlling regional climate, weather, sea levels, and ecosystems. Climate models suggest a potential AMOC slowdown towards the end of this century due to anthropogenic forcing, accelerating coastal sea level rise along the western boundary and dramatically increasing flood risk. While direct observations of the AMOC are still too short to infer long-term trends, we show here that the AMOC-induced changes in gyre-scale heat content, superimposed on the global mean sea level rise, are already influencing the frequency of floods along the United States southeastern seaboard. We find that ocean heat convergence, being the primary driver for interannual sea level changes in the subtropical North Atlantic, has led to an exceptional gyre-scale warming and associated dynamic sea level rise since 2010, accounting for 30-50% of flood days in 2015-2020.

Abstract

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