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The European heatwave has definitely reached Greenland. Nearly 60% of Greenland's surface was melting on July 30th. If today is no higher than that, it will still be the 6th most extensive melt event since satellites began observing in 1979.
nsidc.org/greenland-toda…
nsidc.org/greenland-toda…
Significantly, Summit station at the highest point in Greenland recorded above freezing temperatures. The last melt event at summit was in 2012.
However, we can say much more than that.
When ice sheets melt, some of the water seeps down and refreezes. This creates a distinctive visual layer in an ice core. Because the GISP2 ice core was collected at Summit, we have a record of melt events going back thousands of years.
When ice sheets melt, some of the water seeps down and refreezes. This creates a distinctive visual layer in an ice core. Because the GISP2 ice core was collected at Summit, we have a record of melt events going back thousands of years.
Before 2012, the last time melting occurred at Summit, based on the ice core evidence, was 1889. Before that the next most recent was around the year 1200.
In fact over the last 4,000 years, the average occurrence in the ice core is about one Summit melt event every 250 years.
In fact over the last 4,000 years, the average occurrence in the ice core is about one Summit melt event every 250 years.
Suffice it to say that having melting at Summit, Greenland in both 2012 and 2019 is pretty unexpected if the natural occurrence rate is once every 250 years.
However, recent rapid warming in the Arctic is clearly making such rare melt events much more likely.
However, recent rapid warming in the Arctic is clearly making such rare melt events much more likely.
The July 31st Greenland melt extent data from NSIDC has come in as just slightly higher than the July 30th data, reaching just over 60% of the surface.
Still the 6th most extensive melt event since satellite observations began in 1979.
Still the 6th most extensive melt event since satellite observations began in 1979.
Based on prevailing weather conditions, July 31st should be the peak of this event as colder conditions are now returning to Greenland.
