Science&Tech Zero-degree isotherm over Alps is at the highest altitude recorded Posted on August 22, 2023 3 min read Share on Facebook Share on Twitter Share on Google+ A new altitude record has been set for the freezing point in Switzerland. In the northeastern part of the Alpine country, above Payerne, a weather balloon measured zero degrees Celsius at an altitude of 5,299 meters. The freezing level has never been so high since the beginning of measurements in 1954 as it was last night. The previous record dated back to the previous summer and was at 5,184 meters. This zero-degree isotherm – the line indicating a constant temperature of zero degrees Celsius on the weather map – has a significant impact on vegetation, snowfall, and the water cycle in the Alps. Exceptional warmth “The exceptional warmth currently present in the Alpine region has caused this new record. The high temperatures are the result of North African air descending due to the presence of a high-pressure area. As a result, the air warms up even more above the Alpine region,” explains Belgian glaciologist Lander Van Tricht. It seems that the heat will persist at least until Thursday. “The ongoing heatwave affecting the Alpine countries is quite extraordinary for the second half of August. Normally, the entire month of August in the Swiss lowlands experiences around three to six heatwave days, and in extreme cases like August 2003, even 12 to 18 heatwave days. But even in August 2003, most of these were recorded in the first half of the month. This shows that the current heatwave, which has been lasting for 8 days already, is rare for the second half of August,” says the scientist. Currently, there is only snow cover present on the highest peaks of the Alps. Although the situation is not as extreme as in 2022 when the glaciers lost a record amount of ice, we still seem to be on track for the second most negative year in history.
