While much of the world is focused on the Arctic during this Northern Hemisphere’s summer, my own polar region is once again in the scientific news. Apparently, dramatic year-to-year temperature swings, as well as a century-long warming trend across West Antarctica, are not solely the fault of humans. Granted, we haven’t helped matters.
And while our getting let off the hook a little is and of itself intriguing, the source for West Antarctica’s mysterious temperature swings makes its home in the tropical Pacific Ocean.
“As the tropics warm, so too will West Antarctica,” said the National Center for Atmospheric Research’s (NCAR) David Schneider, who conducted the research with the University of Washington’s (UW) Eric Steig. “These ice cores reveal that West Antarctica’s climate is influenced by atmospheric and oceanic changes thousands of miles to the north.”
While Al Gore may have been the first layman to bring it to public attention, scientists have long been interested in West Antarctica’s reactions to the supposed planetary warming. If the West Antarctic ice-sheet were to melt – whether it would be over a period of decades or centuries – it would raise sea levels globally by approximately 2.5 to 5 meters.
Scientists once determined that Antarctica warmed overall by about .2 degrees Celsius over the last century. However it hasn’t been obvious until recently, with advances in scientific research, that West Antarctica is more responsive to global warming trends than its brother. This could be because West Antarctica is heavier, and thus has weighed heavily upon its land mass, making it more susceptible to warming waters. East Antarctica also is shielded by wind patterns which keep out the comparatively warm air.
So instead of the .2 degrees that was once estimated, Schneider and Steig estimate that West Antarctica has warmed about .9 degrees Celsius over the last century.
In fact, the Antarctic climate as a whole is very especially susceptible to changes in the Pacific. Using a new set of cores that Schneider and Steig retrieved from a snowy part of the continent, the pair were able to acquire details to infer year-to-year temperature changes. For example, during a major El Niño event that took place between 1939 and 1942, temperatures in the West Antarctic shot up 3-6 degrees Celsius before then dropping by an estimated 5-7 degrees Celsius over the following two years.
“These results help put Antarctica’s recent climate trends into a global context,” says Schneider.