While Europe has been hard hit by global warming (floods, forest fires), with temperatures still abnormally high for October, the phenomenon is also being observed in Alaska, where 3 researchers from UCLouvain are currently pursuing their research on permafrost (or permafrost) during the summer-winter transition.
Permafrost on the wane
In permafrost zones, the surface layer of the ground thaws seasonally in summer and refreezes in winter. But with temperatures rising 4X faster in the Arctic than on a global scale, ground thawing is deeper in summer, and winter temperatures no longer allow the entire surface layer to refreeze in winter. The UCLouvain researchers are therefore witnessing an unprecedented phenomenon: part of Alaska’s soil remains thawed at depth throughout the winter. This phenomenon is invisible without the intervention of UCLouvain scientists, since it is hidden beneath the snow cover.
Consequences of thawing
The consequences of this thaw - It leads to the decomposition of organic matter previously protected by the frost, generating the formation of greenhouse gases. To study the extent of this phenomenon, this multidisciplinary UCLouvain team is collecting water samples in the soil (Maëlle Villani), data on snow characteristics (Cécile Osy) and data on soil temperature and humidity (Eléonore du Bois d’Aische).
This mission is an essential step towards quantifying what happens in the soil in winter," explains Sophie Opfergelt, professor at the Faculty of Bioengineering at UCLouvain and mission coordinator. Now that part of the soil remains thawed throughout the winter, it is necessary to consider this season in annual estimates of permafrost greenhouse gas emissions. "
Changes in the landscape in 5 years
Since 2018 and the start of this UCLouvain team’s research in Alaska, the researchers have been able to observe the extent of winter thawing and the resulting degradation of nature: " we’ve seen roads disappear and the landscape change irrevocably in just 5 years. "
The efforts made during this mission as part of the LandSense , LifThaw , and RESIST projects will enable us to take this phenomenon even further in the evolution of Arctic zones influenced by climate change.
