Visualizations of the Arctic often give the impression that the ice cap is a continuous sheet of stationary, floating ice. In fact, it is a collection of smaller pieces that constantly shift, crack, and grind against one another as they are jostled by winds and ocean currents. Especially during the summer—but even during the height of winter—cracks—or leads—open up between pieces of ice.
That was what was happening on the left side of the animation (below) in late January. A high-pressure weather system was parked over the region, producing warmer temperatures and winds that flowed in a southwesterly direction. That fueled the Beaufort Gyre, a wind-driven ocean current that flows clockwise. The gyre was the key force pulling pieces of ice west past Point Barrow, the northern nub of Alaska that protrudes into the Beaufort Sea.
Scientist Ken Dunton is on it, too, and he captures the challenge of change in much more human terms:
To complete today’s infographic trifecta, below is a graphic representation of land and ocean temperatures for Sept. 2012. All that red is enough to make tie it for the warmest September ever, according to NOAA.
September 2012 was tied with 2005 as the globe’s warmest September on record, according to the National Oceanic and Atmospheric Administration’s National Climatic Data Center (NCDC). Global temperature records begin in 1880. NASA rated September 2012 the 4th warmest September on record. September 2012 global land temperatures were the 3rd warmest on record, and global ocean temperatures were the 2nd warmest on record. September 2012 was the 331st consecutive month with global temperatures warmer than the 20th century average. The last time Earth had a below-average September global temperature was in 1976, and the last below-average month of any kind was February 1985. Global satellite-measured temperatures in September 2012 for the lowest 8 km of the atmosphere were 5th or 3rd warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). Wunderground’s weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of September 2012 in his September 2012 Global Weather Extremes Summary.
It seems that government agencies can’t agree on everything. But I think it is safe to conclude they are all saying September was pretty darn warm. And what really jumps out at me are the two sentences I boldfaced.
It’s insane that we are having a debate about whether warming is really occurring instead of what we should be doing about it (ahem–carbon tax). That is an epic failure of leadership, and the triumph of self-interested denialism. History will not be kind to this willful ignorance.
It felt pretty cold down here at latitude 37 degrees, which gave the climate deniers on Capitol Hill plenty of grist for superficial cracks about global warming. But perhaps they should take a look at the top of the world, where January saw the lowest ever recorded extent of Arctic sea ice.
This image shows the average Arctic sea ice concentration for January 2011, based on observations from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA’s Aqua satellite. Blue indicates open water; white indicates high sea ice concentrations; and turquoise indicates loosely packed sea ice. The yellow line shows the average sea ice extent for January from 1979 through 2000.
NSIDC reported that ice extent was unusually low in Hudson Bay, Hudson Strait, and Davis Strait in the early winter. Normally frozen over by late November, these areas did not completely freeze until mid-January 2011. The Labrador Sea was also unusually ice-free.
The shrinking of the polar ice cap is a fascinating story, with untold implications for species, the environment, and human culture and economies. I’m hoping to do some reporting on it very soon.