Unprecedented and Extreme Surface Melt of Greenland in September

News Briefing: NSIDC Greenland Ice Sheet Today, September 2022

An early September heat wave swept across Greenland during the first week of September, causing a melt event unprecedented in the satellite record, with more than one-third of the ice sheet (600,000 square kilometers) experiencing surface melting. Such spikes in surface melt are primarily seen in July, with occasional melt events in June and August. This is the first recorded major melt event in September, when the the setting sun gives little heat to Greenland’s surface. This year however, a narrow band of high-moisture air carried a pulse of warmth across the ice sheet, pushing temperatures above freezing even at Greenland’s highest point, Summit Station, for the time ever in September. A smaller but similarly unprecedented melt event, involving 10-15% of the ice sheet even occurred towards the end of September. The intense melt and subsequent hard freeze during September has also created a hard surface that may increase meltwater run-off and mass loss next spring, as snow meltwater will not be able to percolate down into the ice sheet to the same degree. This melt event suggests that rising temperatures are increasing the likelihood of extreme and unprecedented ice loss across Greenland. Graphs showing these extreme September melting spikes, in comparison to previous years in the satellite record; and a fuller explanation of the early September event are in the link below.

https://nsidc.org/greenland-today/