The Danish Meteorological Institute, which has a key role in monitoring Greenland's climate, last week reported a shocking August temperature of between 2.7C and 4.7C at the Summit weather station, which is located 3,202m above sea level at the the centre of the Greenland ice sheet, generating a spate of global headlines.
But on Wednesday it posted a tweet saying that a closer look had shown that monitoring equipment had been giving erroneous results.
“Was there record-level warmth on the inland ice on Friday?” it said. “No! A quality check has confirmed out suspicion that the measurement was too high.”
?️Var der rekordvarmt på indlandsisen i fredags? Nej! Kvalitetstjek har bekræftet vores formodning om, at målingen var for høj?
Temperaturen på Summit var ikke over 0 grader hverken torsdag 1. aug. eller fredag 2. aug.
— DMI (@dmidk) August 8, 2019
By combining measurements with observations from other weather stations, the DMI has now estimated that the temperature was closer to -2C.
“You could say that this is good news from a climate perspective,” Herdis Damberg, one of the Institute's meteorologists told Danish state broadcaster DR. “There are probably a lot of people wiping their foreheads saying that it's pretty good that it wasn't four degrees.”
The institute believes that snow had caused poor ventilation around the thermometers at the site, wrongly boosting the temperature.
The record temperature ever recorded at Summit is 2.2C, which was reached in both 2012 and 2017. But -2C is still unusual at the station.
“It's not a record, but -2C is still warm,” Damberg said. “It was the heat that lay around Europe that moved up to Iceland and on to Greenland.”
Ruth Mottram, a climate scientist at the institute, told The Local that the revised temperature figure did not affect the institute's estimate that the ice cap lost a record 12.5bn tons of ice in just 24 hours last week, which triggered headlines across the world.
“This does not alter our ice melt figures at all,” she said in an email to The Local, pointing out that while the temperature measurement was taken at about 2m above the ice, her group was “largely interested in the surface temperature”.
The ice melt estimates also did not use the temperature measurements at all, she explained, but was instead based on a “surface energy balance model” which takes into account “all of the sources of incoming and outgoing energy”.