Improved European heat event simulation in eddy-resolving climate models

Abstract Owing to the rapid increase of European heat event occurrences over the past decades, the understanding of their physical drivers has become increasingly important for the scientific community. Recently, it has been shown that cold North Atlantic sea surface temperatures are strongly linked to European heat events such as in summers of 2015 and 2018. Thereby, an accurate representation of this mechanism in climate models is crucial for a more realistic European heat event simulation. Here, we investigate the mechanism by employing seven global coupled climate models, of which six models are embedded in the High Resolution Model Intercomparison Project. Our results show that, compared to the models with low-resolution versions, high-resolution ones simulate a more realistic relationship between North Atlantic sea surface temperatures and European summer temperature extremes. This is attributable to a better reproduction of the North Atlantic trough and the downstream ridge anomalies over central Europe. Improvements in high-resolution ocean configurations reduce the North Atlantic surface biases and improves air-sea interactions, thus having implications for the prediction and projection of climate extremes in the North Atlantic-European region.