Extremely warm European summers preceded by sub-decadal North Atlantic ocean heat accumulation
Open access
Date
2024-01-09Type
- Journal Article
ETH Bibliography
yes
Altmetrics
Abstract
The internal variability of European summer temperatures has been linked to various mechanisms on seasonal to sub-and multi-decadal timescales. We find that sub-decadal timescales dominate summer temperature variability over large parts of the continent and determine mechanisms controlling extremely warm summers on sub-decadal timescales. We show that the sub-decadal warm phases of bandpass-filtered European summer temperatures, hereinafter referred to as extremely warm European summers, are related to a strengthening of the North Atlantic Ocean subtropical gyre, an increase in meridional heat transport, and an accumulation of ocean heat content in the North Atlantic several years prior to the extreme summer. This ocean warming affects the ocean-Atmosphere heat fluxes, leading to a weakening and northward displacement of the jet stream and increased probability of occurrence of high-pressure systems over Scandinavia. Thus, our findings link the occurrence of extremely warm European summers to the accumulation of heat in the North Atlantic Ocean and provide the potential to improve the predictability of extremely warm summers several years ahead, which is of great societal interest. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000659608Publication status
publishedExternal links
Journal / series
Earth System DynamicsVolume
Pages / Article No.
Publisher
CopernicusOrganisational unit
03777 - Knutti, Reto / Knutti, Reto
More
Show all metadata
ETH Bibliography
yes
Altmetrics