Environmental Changes - In Switzerland, permafrost will not recover from being too warm.
After a span of two years with minor snowfall and sweltering summers, the permafrost in Switzerland is receding significantly in numerous locations. The spell between October 2022 and September 2023 held the title of the warmest year-long period since the first measurements in 1864, as revealed by the Swiss Academy of Sciences, situated in Bern.
Dating back to October 2022, the weather patterns have been excessively warm--the temperatures were approximately 1.5 to 1.9 degrees higher than the mean of 1991-2010. Furthermore, the onset of winter was delayed in elevated regions, and snowfall was less than the average amount in past years. Permafrost encompasses rock or gravel that has remained below freezing temperatures for several years.
Alarmingly, the current year is proceding towards breaking negative records as well.
When we take these facts into account, we must focus on the " hydrological" year, which endures from October to September of the subsequent year. This approach provides a more balanced look at rainfall and snowfall. Precipitation that falls between October and winter often melts away as runoff during the following year. At the moment, no equilibrium has been reached for the current hydrological year that lasts up until September 2024. Nonetheless, it is evident that the thaw depth in permafrost regions throughout Switzerland touched or nearly reached historical highs during the summer of 2023.
For instance, at the Schilthorn in the Bernese Alps, the thaw depth was roughly three times thicker than it was two decades ago--clocking in at over 13 meters in 2023. Such extensive thawing was also discovered at various other locations. At the Schafberg block glacier situated near Pontresina, the permafrost subsided by several decimeters, and at the Stockhorn above Zermatt, it plunged by a couple of meters.
A paucity of snow early in winter is a fortunate occurrence for the permafrost.
Following the scorching summer of 2022, record-breaking surface temperatures were documented at several stations within the Swiss Permafrost Monitoring Network (PERMOS). These highs surpassed the readings from the years 2003, 2015, and 2019, mentioned. Consequently, since the surface lacked the insulating snow cover during winter, deeper layers warmed up only a few months later, diluting the earlier high temperatures.
In this regard, Jeannette Nötzli, a scientific staff member at the Institute for Snow and Avalanche Research (SLF) in Davos, conveyed to the German Press Agency, "The absence of snow cover at the beginning of winter proves advantageous for the permafrost. Then, the ground is able to cool more efficiently." Furthermore, during the autumn of 2023, an early snow cover in elevated areas stockpiled heat in the soil. "This caused extremely high temperatures in the upper meters of the ground, which will migrate deeper in the next few months," according to the Academy.
