European mega-heatwaves linked to drought

Heatwaves are the deadliest natural disaster in Europe and have become increasingly frequent and intense in recent years. This summer, Western Europe has already been hit by two severe heatwaves. Researchers from Ghent University and Wageningen University & Research have found a common ingredient of such European mega-heatwaves: drought conditions in the regions the wind blows from. Relying on satellite observations and modelling techniques, the researchers quantify the degree to which air masses warm up in drought locations to then contribute to the escalation of temperatures in the regions downwind. This implies a sequence of natural disasters, in which upwind droughts help unleash downwind heatwaves. Sudden changes in wind direction, transporting heat from these arid locations, can lead to abrupt temperature increases. These 'heat torrents' fuelled by upwind droughts were responsible for about 30% of the heat anomaly during the 2003 and 2010 European mega-heatwaves.