The year ended with a dramatic meltdown in Antarctica. On Christmas Eve, about 15% of the surface ice on Antarctica melted. December 24th saw daytime temperatures between 33°F and 38°F at McMurdo Station in Antarctica. Keep in mind two facts: one is that 15% of the surface ice is not the same as 15% of the total volume of ice on the continent, and two is that much of this meltwater refroze during the night and did not drain into the ocean as meltwater. Still, it is an impressive record.
An added push for this melt award is that from November 2019 through December 27th, the Antarctic production of meltwater entering the ocean was 230% higher than average, and the melt season is not yet over. So, what gives with this balmy Antarctic weather?
Part of the answer to this question lies in the behavior of the southern hemisphere’s polar vortex. A significant weakening of the Antarctica polar vortex occurred before the beginning of this year’s melt season. For reference, a strong polar vortex traps cold air over the south pole and a weak polar vortex allows circumpolar air currents to meander and weaken. These weaker atmospheric circulation patterns then let warm air masses impinge on the continent. Warm air means more melting.
Northern hemisphere awards
On a particularly hot day this past August, temperatures rose above freezing at the highest point on Greenland’s ice sheet. It is believed this is the third time such an event has occurred in the past 700 years. The results were impressive. The island lost 12.5 billion tons of ice in a single day. Remember, there is enough ice in Greenland to raise global sea levels by about 6 meters (20 feet) if it all melts.
August in Greenland was proceeded by the warmest June and July on record for planet earth. This anomalous and erratic weather is again related to our friend, the polar vortex. In this case, the Arctic polar vortex.
Both of these ‘Melt Awards’ are a stern reminder that climate change occurs within a highly interactive web of life that involves the atmosphere, hydrosphere, geosphere, and biosphere. What happens in the remote polar regions spreads its effects outward to the rest of the planet.
Happy New Year – The next article will be on Thursday, January 2nd.
Record Hit for Most Ice to Melt in Antarctica in One Day, Data Suggests (Kashmira Gander – Newsweek) – https://www.newsweek.com/record-hit-ice-melt-antarctica-day-climate-emergency-1479326
Greenland’s Massive Ice Melt Wasn’t Supposed to Happen until 2070 – https://www.forbes.com/sites/scottsnowden/2019/08/16/greenlands-massive-ice-melt-wasnt-supposed-to-happen-until-2070/#5e1c065e4894
Feature Photo: Melting (204911155).jpeg (Photographer: Rob Oo) – This file is licensed under the Creative Commons Attribution 3.0 Unported license. – https://creativecommons.org/licenses/by/3.0/deed.en