Persistent positive anomalies in geopotential heights drive enhanced wildfire activity across Europe

Persistent positive anomalies (PPAs) in 500 hPa geopotential height are upper-air circulation patterns associated with surface heatwaves, drought and fuel aridity. We examined the association between PPA events and surface fire weather and burned area at a pan-European level. Europe-wide, extreme fire weather and wildfires were on average 3.5 and 2.3 times more likely to occur concurrently with a PPA, respectively. PPAs were associated with 45% of pan-European area burned between March and October 2001-2021, and there was a latitudinal increase of up to 63% in the percentage of area burned during or up to 7 days following PPAs over Northern Europe. The burned area was highest up to one week following PPA presence, and fuel moisture indices from the Canadian Fire Weather Index System lagged behind peak PPA strength, demonstrating the role of PPAs in pre-drying fuels. Our findings highlight opportunities for developing early warning systems of wildfire danger, having implications for wildfire awareness and preparedness, informing policy and wildfire management decisions like early mobilization and resource sharing initiatives across Europe.This article is part of the theme issue 'Novel fire regimes under climate changes and human influences: impacts, ecosystem responses and feedbacks'.