The United Nations’ World Meteorological Organization (WMO), on July 1, 2021 recognised a new record high temperature for Antarctica. On February 6, 2020, the Esperanza station (the Argentine research station in Trinity Peninsula) experienced 18.3 degrees Celsius.
Verification of this maximum temperature record is important because it helps us to build up a picture of the weather and climate in one of Earth’s final frontiers. Even more so than the Arctic, the Antarctic is poorly covered in terms of continuous and sustained weather and climate observations and forecasts, even though both play an important role in driving climate and ocean patterns and in sea-level rise.
The Antarctic Peninsula is among the fastest-warming regions of the planet, almost 3°C over the last 50 years. This new temperature record is therefore consistent with the climate change we are observing. The previous record for high temperature was 17.5 degrees Celsius, recorded on March 24, 2015, at the same station.
A WMO committee carried out extensive studies to understand the weather situation during the time of the reported records and noted that a large high-pressure system over the area has created Föhn conditions.
“Föhn or Foehn winds are generally categorised by warm dry air motion descending in the lee or downwind side of a mountain. When the wind hits the mountain in its way, it rises above and causes precipitation in the upwind side of the mountain, while the downwind side of the mountain becomes dry and warm. These winds can warm the surface air temperature in the downwind side by several degrees for a prolonged time”.
Rising global air and ocean temperature are posing a threat to ice sheets and glaciers in the polar regions. The warming temperature and increasing strength of westerly winds can enhance the Antarctic ice sheet melting even in winter due to the Foehn wind effect.