Tuesday, September 24, 2013

Antarctic Sea Ice Sets Modern Era Record On Saturday

The extent of sea ice surrounding Antarctica has set a record for the second consecutive year in the modern era of measurement as the peak of Antarctic ice extent is reached at the end of their winter and as the sun rises at the South Pole for a six month day.

Ice extent in the Southern Hemisphere reached 19.51 million square kilometers according to data posted on the National Snow and Ice Data web site. The old record of 19.48 million was set earlier this month, equaling the 2012 mark.

Modern record keeping dates back into the late 1970's.

Sea ice extent on Saturday compared to median from 1981-2010 (orange line).

The Antarctic, which is seeing record ice is contrasting with the Arctic, which has dealt with years of below average sea ice in its summer. Coming off of a record for lowest sea ice in 2012, this year was a bit less bad in the sea ice standpoint, with the sixth lowest sea ice minimum since the 1970's.

While the Antarctic news is a bit of a surprise for those who are thinking warming planet equals less ice, it comes on the heels of a study that was released on September 13th that shows the potential impacts of how the Antarctic glacier beginning to melt from underneath the glacier could have on ice extent, thickness, and sea level change.  This is due to oceanic temperatures below the sea ice trending above average, sufficient enough to melt the ice from below.  The study measured temperatures during height of the Antarctic summer (December through the end of January) and measures a scale of ice retreat at the bottom of the glacier.  Water temperatures in the Southern Ocean, surrounding Antarctica, were generally above average this past January...which may help in the warming of that subsurface water.

One possible theory that some scientists are kicking around comes regarding the larger extent of the ice near Antarctica is due to a stronger polar vortex in winter, which increases winds around the periphery of the polar jet and helps increase the expanse of ice in winter.

In any event, the sea ice theories in the Antarctic are intriguing and show how much we have to go in fully understanding climate, its continual evolution, and our actual role in shaping that.