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Arctic Ice Hits Annual Max and it’s 6th Lowest on Record

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By Andrew Freedman and Michael D. Lemonick

The skin of sea ice that covers the Arctic Ocean has reached its maximum extent for 2013, the National Snow and Ice Data Center announced Monday, and the annual melt season has begun. As of March 15, ice covered 5.84 million square miles of ocean, the sixth-lowest since satellite observations began in the 1970’s, and 283,000 square miles lower than the 1979-2000 average. Reflecting the influence of global warming, the 10 lowest sea ice maximums have all occurred over the past 10 years.


Animation of the ice fracture using satellite AVHRR data.
Credit: Arctic Sea Ice blog via NSIDC.

Last summer’s ice minimum, moreover, was the lowest on record, with 2007 coming in a distant second. Taken together, it’s one more sign that the planet is warming under the influence of heat-trapping greenhouse gases.

The Arctic is warming especially quickly, however, thanks to a sort of vicious cycle that operates between ice, ocean and sunlight. When the sea is covered with bright, reflective ice, incoming sunlight bounces back into space. When the darker water underneath is exposed, some of the Sun’s energy is absorbed, heating the seawater. That warms the air in turn, increasing the melting and exposing even more dark seawater to the incoming sunlight, and so on.

This feedback cycle, known as Arctic amplification, triggered by warming temperatures, has been reducing ice cover more or less steadily for the past 40 years, at least. This sea ice decline may be impacting areas well outside the Arctic Circle, by setting in motion a chain of events that lead to altered weather patterns in the Northern Hemisphere, favoring some types of extreme weather events. 

The ice returns every winter — and in fact, this winter’s ice growth has been greater than ice experts have seen. But that’s only because last summer’s meltback was so drastic, leaving more open water to freeze. And unlike the thick, multi-year ice that once covered much of the Arctic, this new, seasonal ice cover is very thin, making it prone to rapid melting as the Sun emerges after the months-long winter night.

The thin sea ice is also more prone to cracking when under strain from strong winds or currents. In late February and early March, large fractures were observed in the sea ice cover off the north coast of Canada and Alaska, an event that experts called unusual given the area that was affected.

“That entire region is largely covered by seasonal ice, not multiyear ice, and that’s a real different ice pack than what we used to have,” said Walt Meier, a research scientist at the National Snow and Ice Data Center in Boulder, Colo.

Meier said that thin sea ice is now covering the North Pole itself, which is typically capped by thick ice that survives multiple melt seasons. This is only the second time in the 35-year satellite record that this has happened. The first time was in 2008, following the previous record-low ice extent.

“The amount of hard, thick ice has just collapsed. There are now just remnants of it,” said retired Rear Adm. David Titley, an expert in Arctic climate policy, during a conference call with reporters. “So far, we see no evidence that it’s coming back.”

In recent years, sea ice volume, which includes a measure of ice thickness, has been declining at an even faster rate than sea ice extent.

Average surface temperature anomalies during March 2013. It illustrates the influence of the very strong high pressure area over Greenland, with above average air temperatures there (orange and red) and colder than average conditions in the U.S. and Eurasia. 
Click on the image to enlarge.
Credit: Weatherbell.com.

Titley said the Arctic does not exist in a “vacuum,” and that changes in the Far North will affect countries far to the south. For example, some studies have shown that a warming Arctic has already had a ripple effect on the world’s weather, contributing to outbreaks of cold and stormy weather in parts of Eurasia and the Eastern U.S. in recent winters.

The snowstorms that have affected the U.S. and Europe this March may be an example of a growing Arctic influence in midlatitude weather. March has been an unusually cold and snowy month across a wide swath of the U.S. and Europe, thanks in part to a slow-moving, sprawling area of High pressure above Greenland. While surface air temperatures have been running well above average in Greenland and northeastern Canada, cold Arctic air has surged into the mid-latitudes, effectively delaying spring’s arrival by several weeks in the Midwest and East Coast. 

This type of weather pattern, with a sharp and persistent deviation in the west-to-east flow of air that steers weather systems across the Northern Hemisphere, may be an indication that Arctic warming is already altering the weather in the mid-latitudes, said Steven Vavrus, a senior scientist at the University of Wisconsin-Madison.

Along with Jennifer Francis, a professor at Rutgers University, Vavrus is one of the principal proponents of the hypothesis that rapid Arctic warming is paradoxically causing colder and snowier winters in the mid-latitudes, along with increased bouts of other extreme weather events. Other researchers have expressed different views about how Arctic climate change is affecting the global climate system.

Vavrus said it’s not yet clear if the recent unusual weather pattern can be attributed to the loss of summer sea ice. “One thing that I think is useful is we can use examples like this winter . . . to look at how the climate system behaves,” he said.

Ultimately, scientists believe, the Arctic Ocean could be largely ice-free for much of the summer, a phenomenon that could happen as early as a decade or two from now. That could be good news for shipping companies, which are already looking to save money by taking an Arctic shortcut from Asia to Europe and back; NOAA, meanwhile, is revising its charts of Alaskan waters to help ships and boats navigate newly ice-free waters.

While that may be good for commerce, the heat-absorbing open water in an ice-free Arctic is likely to keep warming the region, leading to changes on land as well. The most worrisome: if the permanently frozen soil, or permafrost, in northern Alaska, Siberia and Canada thaws substantially, it could release massive amounts of carbon that has been deep-frozen for tens of thousands of years, adding an extra burst of heat-trapping greenhouse gases to the atmosphere and turbo-charging the rate of global warming.

As for what the 2013 winter ice maximum means for this summer’s ice minimum, it’s hard to make a prediction. Sea ice extent declined to the 9th-lowest on record in 2012, and the all-time summer low followed six months later. This year’s maximum is lower — but the vagaries of prevailing winds and ocean currents don’t mean we’ll necessarily end the summer with less ice than we did last year. It’s always possible that summer melting will be more moderate than it was in 2012 — after all, it took 5 years after the previous record, set in 2007, for the ice to hit a new low.

But it’s equally possible that Arctic sea ice will shatter last summer’s record. And if it doesn’t happen this year, it will come soon enough.

Editor's Note: This article has been updated to correct an error in the original story. In 2012, the maximum Arctic sea ice extent was the 9th-lowest on record, not the largest amount on record as originally stated.

Related Content
It’s Official: Arctic Sea Ice Shatters Record Low
Arctic Sea Ice Sets Record Low, and it's Not Over Yet
Accelerated Warming Driving Arctic Into New Volatile State
Study Shows A Future In Trans-Arctic Shipping
Climate Change Places Unique Demands on US Naval Forces
NOAA to Map Alaska's Increasingly Ice-Free Arctic Waters
Nearing a Tipping Point on Melting Permafrost?
Warming Arctic May Be Causing Cooler Winters in Eastern U.S.

Comments

By Robert Marston
on March 26th, 2013

It’s worth noting that in most years since 2007, summer sea ice volume hit new record lows. Extent and area only measure what’s visible on the surface. Volume measures total ice.

Reply to this comment

By Lewis Cleverdon (Wales (frozen stiff, littered with dead lambs))
on March 27th, 2013

I note that you are careful to remark that
“Other researchers have expressed different views [than prof.s Francis & Vavrus] about how Arctic climate change is affecting the global climate system.”

Given the plausibility of the decline of arctic sea ice and NH snow cover causing the observed disruption of the NH Jetstream, and the 13-year track of rising occurrence, intensity and duration of the previously rare ‘Greenland Summer High’ alongside that decline, if there is a better hypothesis then perhaps you could describe it on its merits ?

Declaring that such changes “are just random” is not of course a scientific explanation but rather a mere blanket denial of scientists’ endeavours, and I’d hope that opponents of the Francis - Vavrus hypothesis can offer something more constructive.

Given that the Piomass record of the decline of arctic sea ice volume points to a probable total loss in summer occurring from 2016 onwards, then if the proposed explanation of Jetstream disruption is correct, we may face very early intensification of climate destabilization (particularly affecting NH agriculture) as well as the rapid additional acceleration of five mega-feedbacks - of which most are interactive directly as well as via eventual timelagged global warming.

From this perspective identifying the current outcomes of cryosphere decline can be argued to be the issue of supreme urgency, so if there is a cogent alternative hypothesis of the cause of Jetstream disruption it is surely time it was discussed in the public domain.

Regards,

Lewis

Reply to this comment

By Andrew
on March 27th, 2013

Lewis - Some mainstream climate scientists think the sharp fluctuations of the Arctic Oscillation and the jet stream seen in the past few years may not be connected to sea ice decline directly, but that other mechanisms may be at work. One hypothesis is that sea ice is mainly altering the lower atmosphere in the Arctic during the fall season, and is not having as much of an impact outside the Far North as Francis and Vavrus have put forward.

And I don’t think that most scientists would agree with you regarding the view that “random” chance is a “blanket denial.” There have been blocking patterns before, and in fact emerging research goes against the view that blocking is becoming more common/stronger over the N. Atlantic, and natural variability still plays the leading role in governing short-term weather and climate. One can recognize the role that natural variability plays while also holding the view that manmade climate change is a reality, and that the Arctic is transitioning into a new state. This story goes into some more detail: http://www.climatecentral.org/blogs/closer-look-at-arctic-sea-ice-melt-and-extreme-weather-15013 and the stories linked at the bottom of that one do too.

Reply to this comment

By Paul (Santa Monica, CA)
on March 28th, 2013

So, ~6 million square kilometers of sea ice in the north, and its declined by 300 thousand square kilometers from ‘averages’ measured in the 70’s? That equals right about ~5% total change. Ah but the volume the author says! Its the thickness to be alarmed about. OK.

Basic question: What was arctic sea ice coverage in 1960? How about 1860? Anyone wanna try 1960 B.C.? Nobody knows what arctic sea ice coverage was until 40 years ago when LANDSATs started measuring it. And, as is the case with just about anything we actually learn how to look at, we are amazed by what we see. Amazed at how dynamic supposedly ‘permanent’ things are when we actually watch them over any appreciable period of time.

We’ve been surprised that way by the macroscopic universe every time we find a new way to look at it, or a way to look at it at all. The universe in 1900 was a static place of shimmering stars. By 1950 and a couple of scientific revolutions, we were in a universe full of more galaxies of stars than people, stars being born and dying in spectacular ways every day. We do not understand these things, though we know more about them every day because we’ve actually learned how to look at them. That is the state of climate science today.

Reply to this comment

By Jim Hunt (Exeter/Devon/EX6 7YD/UK)
on March 29th, 2013

Hello again Andrew,

To put the record straight once again, the “ice fracture animation” shown above was first published on the Arctic Sea Ice blog on February 22nd, and discussions about those “cracks” had been going on there for a considerable time before that:

http://neven1.typepad.com/blog/2013/02/cryosat-2-reveals-major-arctic-sea-ice-loss/

Now the same area of Arctic sea ice is “fracturing” once again, well ahead of historical “schedule”. For the latest satellite images and photographs taken from a NASA low flying “airborne laboratory” currently in the area please see:

http://econnexus.org/bigger-cracks-than-ever-in-the-beaufort-sea-ice/

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