EGU24-15292, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Unravelling the impact of subpolar gyre variability on climate extremes and variability:  Insights from an ensemble atmospheric model study

Mehdi Pasha Karami1, Torben Koenigk1,3, and Frederik Schenk2,3,4
Mehdi Pasha Karami et al.
  • 1Swedish Meteorological and Hydrological Institute, Rossby Centre, Norrköping, Sweden (
  • 2Department of Geological Sciences, Stockholm University, Stockholm, Sweden
  • 3Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
  • 4Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland

The North Atlantic Subpolar Gyre (SPG) plays an important role in climate predictability and influences climate variability due to its complex coupling with the atmospheric circulation in the North Atlantic and the Atlantic Meridional Overturning Circulation (AMOC). In this study, we investigate the impact of sea surface temperature (SST) variability in the SPG on atmospheric circulation patterns and climate extremes. We use the EC-Earth3 model (T255~80 km) and perform four sets of AMIP-type ensemble experiments with four different prescribed SST anomalies, each with 10 members and spanning 35 years from 1980 to 2014. The experimental design allows the climatic impact of SPG SST variability to be isolated from other global SST modes. Our results show that SPG SST anomalies directly influence atmospheric circulation between 30-75°N, causing zonally oriented wave-like anomalies. Notably, a warm SST anomaly in the subpolar gyre causes strong low-pressure anomalies over the North Atlantic and North Pacific, leading to warming of regions mainly between 45-60°N and cooling of regions mainly between 60-75°N. We find that the anomalous temperatures are particularly pronounced over the North American continent. We also investigate the indirect effects of SPG variability through its synergy with the North Atlantic and North Pacific SSTs, as well as the atmospheric teleconnections and extreme events associated with SPG variability. The results underline the importance of the SPG for the atmospheric circulation, the teleconnections, the regional climate and the extreme events.

How to cite: Karami, M. P., Koenigk, T., and Schenk, F.: Unravelling the impact of subpolar gyre variability on climate extremes and variability:  Insights from an ensemble atmospheric model study, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15292,, 2024.