By: Bob Henson , 5:50 PM GMT on March 03, 2017
As summer draws to a close across the Southern Hemisphere, the extent of sea ice ringing Antarctica has fallen to the lowest values ever observed in satellite records dating back to 1979. On Wednesday, March 1, the daily extent data from the National Snow and Ice Data Center (NSIDC) showed 2,109,000 square kilometers of Antarctic sea ice, its lowest value on record. That value nudged up slightly on Thursday, but a more useful measure, the five-day rolling average, hit its lowest value yet on Thursday (see Figure 1 below). Update: The five-day average fell even lower on Friday, March 3, dropping from 2,113,000 to 2,106,000 sq. km.
“It’s possible that we’ll look back in a decade and see this year as a turning point when the Antarctic sea ice finally started to feel the long-term global warming influence above the natural variability,” Meier told me. “But we may also look back and see this year as an unusual blip in the time series--an anomalous spike that is quickly gone.”