EGU26-7405, updated on 14 Mar 2026
https://doi.org/10.5194/egusphere-egu26-7405
EGU General Assembly 2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
Oral | Thursday, 07 May, 15:00–15:10 (CEST)
 
Room 0.49/50
Enhanced weather persistence due to amplified Arctic warming
Rune Grand Graversen1, Rachel White2, and Timo Vihma3
Rune Grand Graversen et al.
  • 1University of Tromsø, Department of Physics and Technology, Tromsø, Norway (rune.graversen@uit.no)
  • 2University of British Columbia, Canada
  • 3Finnish Meteorological Institute, Finland

Changing weather is an aspect of global warming potentially constituting a major challenge for humanity in the coming decades. Some climate models indicate that, due to global warming, future weather will become more persistent, as regard surface-air temperature anomalies lasting longer. However, to date, an observed change in weather persistence has not been robustly confirmed. Here we show that weather persistence in terms of temperature anomalies, across all weather types and seasons, has increased during recent decades in the Northern Hemisphere mid-latitudes.

This persistence increase is linked to Arctic temperature amplification – the Arctic warming faster than the global average – and hence global warming. The Arctic amplification weakens the meridional geopotential-height gradient at 500 hPa, which, through geostrophic balance and the thermal wind relation, leads to a reduction of the westerly zonal mass flow (density-weighted zonal winds integrated through the atmosphere) in the northern midlatitudes. The westerly atmospheric mass flow helps transport weather systems such as cyclones and other weather anomalies. Hence, when the background flow reduces, the transport of weather systems slows, and the local weather tends to become more persistent.

Persistent weather may lead to extreme weather, and for many plants such as crops, weather persistence can be devastating, as these plants often depend on weather variations. Hence, our results call for further investigation of weather-persistence impact on extreme weather, biodiversity, and the global food supply.

Graversen, R.G., White, R.H. & Vihma, T. Enhanced weather persistence due to amplified Arctic warming. Commun Earth Environ 6, 997 (2025). https://doi.org/10.1038/s43247-025-03050-1

How to cite: Graversen, R. G., White, R., and Vihma, T.: Enhanced weather persistence due to amplified Arctic warming, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-7405, https://doi.org/10.5194/egusphere-egu26-7405, 2026.