Connecting Marine and Terrestrial Extremes: Oceanic Drivers of Temperature and Precipitation in Europe

Weather extremes are becoming more frequent and intense across Europe, as climate change transforms once-rare events into more common and severe occurrences with major consequences for society, calling for revised adaptation and mitigation strategies. When extremes such as terrestrial heatwaves and droughts occur in combination (CDHWs), their compound effects may lead to amplified impacts, creating complex, multiscale challenges. At the same time, marine heatwaves (MHWs) are rising in intensity, duration, and frequency, profoundly affecting marine ecosystems and showing potential relationship to terrestrial extreme weather. In Europe, both oceanic and land-based heat extremes display parallel warming trends, underscoring the connectivity of Earth’s subsystems, yet the regional teleconnections that drive this connectivity remain insufficiently explored. Understanding the relationship among heatwaves, droughts, and MHWs requires robust detection and characterisation of compound events, drawing on statistical, empirical, high-dimensional, and network analysis methods. Within the ESA XHEAT project, we are leveraging Earth Observation data to expose common spatiotemporal signatures of these extremes and to test the hypothesis that North Atlantic MHWs modulate the persistence and intensity of terrestrial heatwaves and droughts, focusing on the Iberian Peninsula, the Mediterranean basin, and Scandinavia. Early results reveal coherent patterns that suggest strong linkages between oceanic heat extremes and concurrent atmospheric extremes, supporting improved probabilistic seasonal forecasting. In addition, we are integrating machine learning techniques into traditional MHWs detection workflows to develop a mechanistic, spatiotemporal approach that captures the connectivity of these anomalies. Our work aims to enhance the understanding of how ocean–atmosphere interactions contribute to interconnected risks, enabling better prediction of such events, anticipating their impacts and promoting timely response measures to mitigate them, and thus aiming to support improved preparedness and resilience in Europe.