The Role of the North Atlantic for Heat Wave Characteristics in Europe, an ECHAM6 Study

Abstract The recent severe European summer heat waves of 2015 and 2018 co‐occurred with cold subpolar North Atlantic (NA) sea surface temperatures (SSTs). However, a significant connection between this oceanic state and European heat waves was not yet established. We performed two AMIP‐like model ex...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Sabine Bischof, Robin Pilch Kedzierski, Martje Hänsch, Sebastian Wahl, Katja Matthes
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2023
Subjects:
Online Access:https://doi.org/10.1029/2023GL105280
https://doaj.org/article/9af959f92b324bfa8b692166a1c1941f
Description
Summary:Abstract The recent severe European summer heat waves of 2015 and 2018 co‐occurred with cold subpolar North Atlantic (NA) sea surface temperatures (SSTs). However, a significant connection between this oceanic state and European heat waves was not yet established. We performed two AMIP‐like model experiments: (a) employing daily 2018 SSTs as observed and (b) applying a novel approach to remove the negative NA SST anomaly, while keeping SST daily and small‐scale variability. Comparing these experiments, we find that cold subpolar NA SSTs significantly increase heat wave duration and magnitude downstream over the European continent. Surface temperature and circulation anomalies are connected by the upper‐tropospheric summer wave pattern of meridional winds over the North Atlantic European sector, which is enhanced with cold NA SSTs. Our results highlight the relevance of the subpolar NA region for European summer conditions, a region that is marked by large biases in current coupled climate model simulations.