NSIDC calls maximum Arctic sea ice extent
March 27th, 2012The National Snow and Ice Data Center says the Arctic sea ice melt season has finally begun:
On March 18, 2012, Arctic sea ice extent reached its annual maximum extent, marking the beginning of the melt season for Northern Hemisphere sea ice. This year’s maximum extent was the ninth lowest in the satellite record.
Sea ice appeared to have reached its maximum extent earlier in the month on March 6 – but an unexpected change in Arctic weather lead to a late-season surge.
The maximum this year was very late compared to recent years, occurring 12 days later than the 1979 to 2000 average date of March 6.
- March 6th 2005: 13.46
- March 11th 2006: 13.36
- February 26th 2007: 13.32
- March 11th 2008: 13.89
- March 2nd 2009: 13.85
- March 7th 2010: 13.81
- March 8th 2011: 13.14
- March 20th 2012: 13.70
This year’s maximum ice extent was 15.24 million square kilometers (5.88 million square miles), 614,000 square kilometers (237,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles). This year’s maximum was the ninth lowest in the satellite record. Last year (2011) was the lowest maximum on record at 14.64 million square kilometers (5.65 million square miles). Including this year, the nine years from 2004 to 2012 are the nine lowest maximums in the satellite record.
Sea ice extent in February and March tends to be quite variable, because ice near the edge is thin and often quite dispersed. The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks, as it has done this year. NSIDC’s call includes this caveat:
As of March 23, ice extent has declined for five days. However, there is still a chance that the ice extent could expand again.
Why should we care about what’s happening in the Arctic? Because the Arctic is the “canary in the coal mine”, warming faster than anyplace else on Earth.
The warming Arctic is already affecting Earth’s weather. The erratic weather and extreme weather events seen over last few years are merely a foretaste of what’s in store for the future. Jennifer A. Francis, a Rutgers University climate researcher, is quoted in the New York Times:
Climate mechanisms in the Arctic are a major driver of weather in the northern hemisphere, including not only “über-extreme” weather events but also the weird and unpredictable weather affecting crops and livelihoods at home, like here in Oregon. What happens in the Arctic directly impacts us in our daily lives.















