EGU21-7067
https://doi.org/10.5194/egusphere-egu21-7067
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Weakening Satellite Era and Future Tropical Atlantic Sea Surface Temperature Variability

Arthur Prigent1, Rodrigue Anicet Imbol Koungue1, Joke Lübbecke1,2, Peter Brandt1,2, Jan Harlaß1, and Mojib Latif1,2
Arthur Prigent et al.
  • 1GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Physical Oceanography, Kiel, Germany (aprigent@geomar.de)
  • 2Faculty of Mathematics and Natural Sciences, Christian Albrechts University, Kiel, Germany

Since 2000, a substantial weakening in the equatorial and southeastern tropical Atlantic sea surface temperature (SST) variability is observed. Observations and reanalysis products reveal, for example, that relative to 1982–1999, the March‐April‐May SST variability in the Angola‐Benguela area (ABA) has decreased by more than 30%. Both equatorial remote forcing and local forcing are known to play an important role in driving SST variability in the ABA. Here we show that compared to 1982–1999, since 2000, equatorial remote forcing had less influence on ABA SSTs, whereas local forcing has become more important. In particular, the robust correlation between the equatorial zonal wind stress and the ABA SSTs has substantially weakened, suggesting less influence of Kelvin waves on ABA SSTs. Moreover, the strong correlation linking the South Atlantic Anticyclone and the ABA SSTs has reduced. Multidecadal surface warming of the ABA could also have played a role in weakening the interannual SST variability.

To investigate future changes in tropical Atlantic SST variability, an ensemble of nested high-resolution coupled model simulations under the global warming scenario RCP8.5 is analyzed. SST variability in both the ABA and equatorial cold tongue is found to decrease along with reduced western equatorial Atlantic zonal wind variability.  

How to cite: Prigent, A., Imbol Koungue, R. A., Lübbecke, J., Brandt, P., Harlaß, J., and Latif, M.: Weakening Satellite Era and Future Tropical Atlantic Sea Surface Temperature Variability, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7067, https://doi.org/10.5194/egusphere-egu21-7067, 2021.

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