Antarctic temperature record tumbles again
A weather research station on the Antarctic Peninsula has registered a temperature of 20.75 degrees Celsius, appearing to topple a record set just days earlier.
The new mark was recorded on Seymour Island on February 9, said Marcio Rocha Francelino, a professor at the Federal University of Vicosa in Brazil.
The temperature is significantly higher than the 18.3C reading taken on February 6 at the Esperanza Base on the Trinity Peninsula. The World Meteorological Organisation (WMO) is reviewing that reading to see whether it qualifies as the continent’s hottest temperature on record.
The new data came from a research station that has been in place for 12 years, used mainly for monitoring the layer of permanently frozen soil known as permafrost.
Randall Cerveny, a meteorologist at Arizona State University who verifies extremes for the WMO, previously called the Esperanza reading a ‘‘likely record’’.
He said the organisation was looking into the new report as well, but urged caution about the higher reading. ‘‘We will want to look very critically at the station’s metadata (how long was it in place, how good has its observations been, what type of instruments were used, when were they last calibrated etc),’’ he said in an email.
Francelino said the weather station in question was one of 26 that he and other researchers operated around Antarctica.
Jefferson C Simoes, a glaciologist at the Federal University of Rio Grande do Sul and a vicepresident of the Scientific Committee on Antarctic Research, who also confirmed the reading, said he did notbelieve it would meet the WMO’s criteria for an official record, ‘‘because it was not measured in [a] standard weather station with a long time record (of measurements)’’.
Nevertheless, he considered it important for confirming a ‘‘heatwave’’ in the northernmost part of Antarctica in the past week.
Both locations are located in the area of Antarctica that is closest to South America, whereas the continent’s interior reaches are the coldest parts.
According to Francelino, the Seymour Island station registered a temperature of 16.4C on February 6, when Argentina’s Esperanza Station reached 18.3C.
Then, on February 9, the Brazilian Antarctic Station on King George Island registered a temperature of 19.38C at the same time the permafrost research station soared closer to 21C.
‘‘I don’t know whether Esperanza’s or the Brazilian stations are registered or follow the WMO standard, but the mere recording of these values is something that should be better studied,’’ Francelino said.
Computer model forecasts had suggested that large parts of the Antarctic Peninsula would have temperatures above normal between February 7 and 9, as an unusually strong high-pressure zone was in the vicinity.
The average temperature in the first days of February at the Seymour Island research station was a more typical 3.9C.
‘‘In our sites, over a period of 13 years, the temperature of permafrost has been varying very little, remaining stable in most of them and in some showing a slight tendency of heating. Only one showed cooling,’’ Francelino said.
This is compared with the rapid warming in the vast permafrost of the Arctic, the melting of which may already constitute a major climate feedback that will accelerate global warming.
The Antarctic Peninsula is one of the fastest-warming parts of the world. Most of the glaciers in the region are retreating rapidly. According to a 2018 study, ice shelf collapse and the speeding up of glacier movement into the sea at the Antarctic Peninsula caused an increase of 25 billion tonnes of ice loss per year from the region between 1992 and 2017.
The region has most famously seen the sudden breakups of two large floating ice shelves: the Larsen B Ice Shelf in 2002, and the Wilkins Ice Shelf in 2008.
The rapid warming has led to more consistent scientific monitoring, as researchers’ concerns about ice loss shift to include virtually the entire continent.