Effect of Anthropogenic Forcing on Anomalous Hydroclimate Events in Europe Detected by an Autoencoder

Large-scale precipitation events and record heat waves have occurred more frequently across Europe in recent years than before. However, the mechanism driving these anomalous climate events remains elusive, making it difficult to adequately describe such events and separate anthropogenic effects from natural variability. In this study, we identify anomalous hydroclimate events, specifically daily maximum surface air temperature and daily precipitation in Europe using a deep learning autoencoder. We examine the relationship between temperature and precipitation extremes and whether these events are increasing due to climate change. The deep learning technique allows us to detect anomalous temperature extremes, precipitation events, and compound events in both observations and simulations. We find that anomalous events–both precipitation and compound events– have been increasing in Europe during 1971-2023, with anthropogenic forcing playing an important role. Additionally, we find an increasing number of heavy precipitation events occurring at lower local maximum temperatures in Central Europe, but relatively dry events at higher temperatures in the surrounding regions. Anomalous events are projected to continue increasing toward the end of this century with more frequent anomalous events under higher greenhouse gas concentrations, according to different Socioeconomic Shared Pathways (SSPs) emission scenarios. These results highlight the impact of anthropogenic forcing on the increase in anomalous precipitation and temperature events, as well as their compound occurrences, in Europe.