The beginning of February 2020, marked the hottest days on record for Antarctica. Thermometers at the Esperanza Base on the northern tip of the Antarctic Peninsula reached 18.3°C (64.9°F) resulting in melting on glaciers.
The heatwave lasted over a week. NASA's Operational Land Imager (OLI) on Landsat 8 caught images of the melting on February 4 and February 13, 2020, and they are worrisome, to say the least.
"I haven't seen melt ponds develop this quickly in Antarctica," said Mauri Pelto, a glaciologist at Nichols College.
"You see these kinds of melt events in Alaska and Greenland, but not usually in Antarctica."
Sustained high temperatures
Pelto also added that such shockingly rapid melting can only be caused by sustained high temperatures. Such weather patterns were not seen in Antarctica until the 21st century, but they have become more common in the past few years.
Several elements contributed to this rise in temperature. A ridge of high pressure over Cape Horn allowed warm temperatures to build while the strong winds called the Southern Hemisphere westerlies were in weak condition.
Without the winds there to impede its development, the heatwave crossed the Southern Ocean and made it all the way to the ice sheet. In the meantime, sea surface temperatures did not help as they were higher than average.
Finally, foehn winds, known for bringing warm air with them, ran into the Antarctic Peninsula Cordillera creating blasts of heat. The winds also caused drier air which in turn impeded the formation of low-lying clouds and potentially allowed for more direct heating sunlight.
More worrisome is that this heatwave is not the only one this past year. In fact, it was the third major melt event of the summer. With researchers pointing out that many more heatwaves are to come, the temperatures keep rising in Antarctica.
“If you think about this event in February, it isn’t that significant,” said Pelto. Also stating that“It’s more significant that these events are coming more frequently."