Moisture recycling and the potential role of forests as moisture source during European heatwaves
Heatwaves are extreme weather events that have become more frequent and intense in Europe over the past decades. Heatwaves are often coupled to droughts. The combination of them lead to severe ecological and socio-economic impacts. Heatwaves can self-amplify through internal climatic feedback that reduces local precipitation.
Understanding the terrestrial sources of local precipitation during heatwaves might help identify mitigation strategies on land management and change that alleviate impacts. Moisture recycling of local water sources through evaporation allows a region to maintain precipitation in the same region or, by being transported by winds, in adjacent regions. To understand the role of terrestrial moisture sources for sustaining precipitation during heatwaves, we backtrack and analyse the precipitation sources of Northern, Western, and Southern sub-regions across Europe during 20 heatwave periods between 1979 and 2018 using the moisture tracking model Water Accounting Model-2layers (WAM-2layers).
In Northern and Western Europe, we find that stabilizing anticyclonic patterns reduce the climatological westerly supply of moisture, mainly from the North Atlantic Ocean, and enhances the moisture flow from the eastern Euro-Asian continent and from within their own regions—suggesting over 10% shift of moisture supply from oceanic to terrestrial sources. In Southern Europe, limited local moisture sources result in a dramatic decrease in the local moisture recycling rate. Forests uniformly supply additional moisture to all regions during heatwaves and thus contribute to buffer local impacts.
This study suggests that terrestrial moisture sources, especially forests, may potentially be important to mitigate moisture scarcity during heatwaves in Europe.
Research news | 2022-09-23
Civil society could be the gamechanger for climate policymaking
To make climate policies fair and effective we need to harness the power of civil society, argues centre researcher Thomas Hahn
Research news | 2022-09-19
Turning food by-products into fodder could feed a billion people
Using waste from food production to feed livestock and aquaculture could help feed more people with less
Research news | 2022-09-13
Mutual interests and benefits are no guarantee for increased collaboration
Awareness of interdependencies may not promote, but instead even inhibit, exchange and dialogue between different policy actors
Research news | 2022-09-08
World at risk of passing multiple climate tipping points above 1.5°C global warming
Human emissions have already pushed Earth into the danger zone. Five of sixteen identified tipping point may be triggered at today’s temperatures
Research news | 2022-09-08
To value the environment means acknowledging pluralism
Acknowledging a diversity of values is an absolute necessity for good decision-making
Research news | 2022-09-01
New book “Earth For All: a survival guide to humanity”
Landmark global analysis sets out survival pathways for humanity