Acceleration of U.S. Southeast and Gulf coast sea-level rise amplified by internal climate variability

Sönke Dangendorf; Noah Hendricks; Qiang Sun; John Klinck; Tal Ezer; Thomas Frederikse; Francisco M Calafat; Thomas Wahl; Torbjörn E Törnqvist

doi:10.1038/s41467-023-37649-9

Acceleration of U.S. Southeast and Gulf coast sea-level rise amplified by internal climate variability

Nat Commun. 2023 Apr 10;14(1):1935. doi: 10.1038/s41467-023-37649-9.

Authors

Sönke Dangendorf¹, Noah Hendricks², Qiang Sun³, John Klinck², Tal Ezer², Thomas Frederikse⁴, Francisco M Calafat⁵, Thomas Wahl⁶, Torbjörn E Törnqvist⁷

Affiliations

¹ Department of River-Coastal Science and Engineering, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118, USA. sdangendorf1@tulane.edu.
² Center for Coastal Physical Oceanography, Department of Ocean and Earth Sciences, Old Dominion University, 4111 Monarch Way, Norfolk, VA, 23508, USA.
³ Department of River-Coastal Science and Engineering, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118, USA.
⁴ Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
⁵ National Oceanography Centre, 6 Brownlow Street, Liverpool, L3 5DA, UK.
⁶ Department of Civil, Environmental and Construction Engineering, University of Central Florida, Orlando, 32816, FL, USA.
⁷ Department of Earth and Environmental Sciences, Tulane University, 6823 St. Charles Avenue, New Orleans, LA, 70118, USA.

Abstract

While there is evidence for an acceleration in global mean sea level (MSL) since the 1960s, its detection at local levels has been hampered by the considerable influence of natural variability on the rate of MSL change. Here we report a MSL acceleration in tide gauge records along the U.S. Southeast and Gulf coasts that has led to rates (>10 mm yr^-1 since 2010) that are unprecedented in at least 120 years. We show that this acceleration is primarily induced by an ocean dynamic signal exceeding the externally forced response from historical climate model simulations. However, when the simulated forced response is removed from observations, the residuals are neither historically unprecedented nor inconsistent with internal variability in simulations. A large fraction of the residuals is consistent with wind driven Rossby waves in the tropical North Atlantic. This indicates that this ongoing acceleration represents the compounding effects of external forcing and internal climate variability.

Grants and funding

80NSSC20K1241/National Aeronautics and Space Administration (NASA)