Antarctica has reached a new record high temperature of 18.3 degrees Celcius, new data has confirmed.
A Victoria University of Wellington researcher is part of the 12-person World Meteorological Organisation (WMO) evaluation team whose extensive review led to the confirmation today.
Climate change expert Professor James Renwick, who heads the University’s School of Geography, Environment and Earth Sciences, and colleagues from Brazil, Argentina, the United Kingdom, the United States and Spain verified the temperature of 18.3 degrees Celsius recorded at Argentina’s Esperanza station on February 6, 2020.
However, they rejected a temperature of 20.75 degrees reported at a Brazilian automated permafrost monitoring station on Seymour Island on 9 February 2020.
The previous record for the continent was 17.5 degrees recorded at Esperanza station on 24 March 2015. The record for the Antarctic region as a whole, including all ice and land south of 60° latitude, is 19.8 degrees, taken at the UK’s Signy Island station in January 1982.
“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,” WMO Secretary-General Professor Petteri Taalas said.
“The Antarctic Peninsula [the northwest tip near to South America] is among the fastest warming regions of the planet, almost 3 degrees over the last 50 years. This new temperature record is therefore consistent with the climate change we are observing."
The team of which Professor Renwick was a member was commissioned by WMO’s Weather and Climate Extremes Archive to review the weather situation on the Antarctic Peninsula at the time of the two latest reported records.
It determined that a large high-pressure system over the area created föhn conditions (downslope winds producing significant surface warming) and resulted in local warming at both Esperanza and Seymour Island stations. Past evaluations have demonstrated that such meteorological conditions are conducive for producing record temperature scenarios.
Professor Renwick said föhn conditions also caused Aotearoa New Zealand’s highest recorded temperatures.
“The hottest day ever recorded in Aotearoa is still 42°C in Rangiora and Christchurch, and other places in Canterbury, on 7 February 1973. That happened in a big nor’westerly event just like the one that caused the new record for the Antarctic.
“The Antarctic Peninsula has mountains running down its length, perpendicular to the flow of the north-west winds, so places on the eastern side of the Peninsula can experience very warm days, just like in Canterbury, which lies downwind of the Southern Alps.”