Greenland Hit 75 Degrees June
TORONTO – According to a new data, 2015 was a record year for high temperatures and melting glaciers in western Greenland.
The rise in temperatures could lead to accelerated warming in the Arctic.
A new report from the Lamont-Doherty Earth Observatory at Columbia University attributes the warming to a shift in the jet stream that brought higher temperatures to much more northerly latitudes than normal last year.
The warmer air and melting ice magnify each other in a feedback loop called Arctic amplification.
“This is the sixth earliest onset of ice loss in our 27-year record, although there isn’t really a large difference from one year to the next in the top-ranking 17 years,” said climate scientist Peter Langen.
In the same way that white clothing feels cooler than black on a sunny summer day, white ice reflects sunlight, keeping temperatures at the surface low. When the ice melts, dark sea water and dark land are exposed. These absorb sunlight rather than reflecting it, thus raising temperatures and causing more melting. The cycle continues, and even speeds up, as the dark areas grow larger and white ice disappears.
This is one reason the Arctic is heating up faster than other parts of the globe.
“This study highlights how the many elements of the system are working together,” says Marco Tedesco, a glaciologist at Columbia University and the first author of the study, published today in Nature Communications. “It’s crucial we understand how the different parts are driving Greenland’s melting.”
The melt began in June when a ridge of high-pressure brought clear skies and warm weather to northern Greenland. This, in turn, set records for surface temperature in the region and meltwater runoff. Because of the warmer temperatures and runoff, this led to less reflectivity helping drive the warmer temperatures.
Records were also set when it came to winds. Typically, the winds blow west to east in the region. Instead, on average, they blew east to west.
Greenland’s ice sheet is the second-largest after that of Antarctica. If it were to completely melt it would rise the average sea level by six metres.
Photo of the south-east coast of greenland taken with a Canon Ixus II