Arctic Continues to Break Records in 2012

Ice concentration on Sept. 16, 2012, compared to previous record low (yellow line) and historic median extent (black line.) Credit: NOAA/ NAtional Snow and Ice Data Center

The Arctic region continued to break records in 2012—among them the loss of summer sea ice, spring snow cover, and melting of the Greenland ice sheet.

This was true even though air temperatures in the Arctic were unremarkable relative to the last decade, according to a new report released today.

“The Arctic is changing in both predictable and unpredictable ways, so we must expect surprises,” said Jane Lubchenco, Ph.D., under secretary of commerce for oceans and atmosphere and NOAA administrator, during a press briefing at the American Geophysical Union annual meeting in San Francisco, Calif. “The Arctic is an extremely sensitive part of the world and with the warming scientists have observed, we see the results with less snow and sea ice, greater ice sheet melt and changing vegetation.”

Lubchenco participated in a panel discussion that presented the annual update of the Arctic Report Card, which has, since 2006, summarized the quickly changing conditions in the Arctic. A record-breaking 141 authors from 15 countries contributed to the peer-reviewed report. Major findings of this year’s report include:

• Snow cover: A new record low snow extent for the Northern Hemisphere was set in June 2012, and a new record low was reached in May over Eurasia.
  
  
• Sea ice: Minimum Arctic sea ice extent in September 2012 set a new all-time record low, as measured by satellite since 1979.
  
  
• Greenland ice sheet: There was a rare, nearly ice sheet-wide melt event on the Greenland ice sheet in July, covering about 97 percent of the ice sheet on a single day.
  
  
• Vegetation: The tundra is getting greener and there’s more above-ground growth. During the period of 2003-2010, the length of the growing season increased through much of the Arctic.
  
  
• Wildlife & food chain: In northernmost Europe, the Arctic fox is close to extinction and vulnerable to the encroaching Red fox. Additionally, recent measurements of massive phytoplankton blooms below the summer sea ice suggest that earlier estimates of biological production at the bottom of the marine food chain may have been ten times lower than was occurring.
  
  
• Ocean: Sea surface temperatures in summer continue to be warmer than the long-term average at the growing ice-free margins, while upper ocean temperature and salinity show significant interannual variability with no clear trends.
  
  
• Weather: Most of the notable weather activity in fall and winter occurred in the sub-Arctic due to a strong positive North Atlantic Oscillation, expressed as the atmospheric pressure difference between weather stations in the Azores and Iceland. There were three extreme weather events including an unusual cold spell in late January to early February 2012 across Eurasia, and two record storms characterized by very low central pressures and strong winds near western Alaska in November 2011 and north of Alaska in August 2012.