Tag: sea ice

Watching The Arctic Change

NASA is on it, with satellite imagery and video:

The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this view of extensive sea-ice fracturing off the northern coast of Alaska. The event began in late-January and spread west towardBanks Island throughout February and March 2013.

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:

Arctic Ice Extent At Record Low In January

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.

From NASA:

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.

Enhanced by Zemanta
%d bloggers like this: