Meltdown Alert: Greenland’s Ice Sheets, a cause for alarm!
Late June brought significant weather changes to Greenland, leading to a record pace of melting, especially in the southern part of the ice sheet known as the South Dome. Air temperatures have been above average, rising by 1.5 to 2 degrees Celsius (3 to 4 degrees Fahrenheit) in the south and over 3 degrees Celsius (5 degrees Fahrenheit) in the north-central area.
Changing air pressure patterns have led to higher-than-average pressure in both the southwest and the northeast of the island. This pattern has brought a series of warm air pulses across the island from the southwest, intensifying surface melting and runoff. During the first half of July, estimated daily melt totals reached 15 billion tons, with melt run-off at about 10 billion tons per day, both significantly higher than average. Throughout June 27, July 6 to 7, and July 11, there have been several widespread melting events, covering about 800,000 square kilometers (302,000 square miles) or up to 50 percent of the ice sheet. The total number of days with melting has surpassed the average, with the southern and southwestern portions experiencing 5 to 15 extra melting days and the northern flank experiencing about 10 additional days of melting. In terms of total melt-day extent, this season now ranks sixth highest overall, and the southern ice sheet is currently experiencing a record high for the 45-year satellite record.
“Heat domes such as what has been happening over northwest Africa and southern Europe can also happen over Greenland. During the first half of July, high pressure over Greenland brought in warm winds from the south and clear skies that have led to significant melting.” [Julienne Stroeve, Chief Scientist Officer at Arctic Basecamp and Arctic Climate Scientist].
Negative North Atlantic Oscillation (NAO) conditions are expected to persist until the end of July, resulting in even more melting. In fact, it is projected that the total runoff at the South Dome during July will surpass the previous record years of 2002, 2007, 2012, and 2019. The southern and northeastern areas experienced below-average snowfall and frequent rainfall, pre-conditioning the surface for further melting, especially near the coast with exposed ice-covered ablation areas.
The sudden shift to southern heat requires close monitoring, as this rapid melting will have serious implications for global sea levels and climate patterns. Let’s not forget that melting ice sheets mean higher seas and that the Greenland Ice Sheet contains the equivalent of 7.4 metres of sea level rise. It is now the largest contributor to global sea level rise at up to 1.4 mm per year and Greenland’s increased rate of ice melt will massively disrupt coastal communities and economies across the world.