Featured Research

from universities, journals, and other organizations

Arctic Ocean is on thin ice: European satellite confirms numbers

Date:
February 13, 2013
Source:
University of Washington
Summary:
The September 2012 record low in Arctic sea-ice extent was big news, but a missing piece of the puzzle was lurking below the ocean's surface. What volume of ice floats on Arctic waters? And how does that compare to previous summers? These are difficult but important questions, because how much ice actually remains suggests how vulnerable the ice pack will be to more warming. New satellite observations confirm an analysis that for the past three years has produced widely quoted estimates of Arctic sea-ice volume. Findings based on observations from a European Space Agency satellite show that the Arctic has lost more than a third of summer sea-ice volume since a decade ago, when a U.S. satellite collected similar data.

Seasonal ice on the Chuchki Sea, a marginal sea off the Arctic Ocean, in July 2010.
Credit: Bonnie Light, UW

The September 2012 record low in Arctic sea-ice extent was big news, but a missing piece of the puzzle was lurking below the ocean's surface. What volume of ice floats on Arctic waters? And how does that compare to previous summers? These are difficult but important questions, because how much ice actually remains suggests how vulnerable the ice pack will be to more warming.

New satellite observations confirm a University of Washington analysis that for the past three years has produced widely quoted estimates of Arctic sea-ice volume. Findings based on observations from a European Space Agency satellite, published online in Geophysical Research Letters, show that the Arctic has lost more than a third of summer sea-ice volume since a decade ago, when a U.S. satellite collected similar data.

Combining the UW model and the new satellite observations suggests the summer minimum in Arctic sea ice is one-fifth of what it was in 1980, when the model begins.

"Other people had argued that 75 to 80 percent ice volume loss was too aggressive," said co-author Axel Schweiger, a polar scientist in the UW Applied Physics Laboratory. "What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid."

The system developed at the UW provides a 34-year monthly picture of what's happening to the total volume of Arctic sea ice. The Pan-Arctic Ice Ocean Modeling and Assimilation System, or PIOMAS, combines weather records, sea-surface temperature and satellite pictures of ice coverage to compute ice volume. It then verifies the results with actual thickness measurements from individual moorings or submarines that cruise below the ice.

"Because the ice is so variable, you don't get a full picture of it from any of those observations," Schweiger said. "So this model is the only way to reconstruct a time series that spans multiple decades."

The UW system also checks its results against five years of precise ice thickness measurements collected by a specialized satellite launched by NASA in 2003. The Ice, Cloud, and Land Elevation Satellite, or ICESat, measured ice thickness across the Arctic to within 37 centimeters (15 inches) until spring of 2008.

The U.K.'s CryoSat-2 satellite resumed complete ice thickness measurements in 2010; this is the first scientific paper to share its findings about the recent years of record-low sea ice.

Between 2008 and now, the widely cited UW figures have generated some controversy because of the substantial ice loss they showed.

"The reanalysis relies on a model, so some people have, justifiably, questioned it," Schweiger said. "These data essentially confirm that in the last few years, for which we haven't really had data, the observations are very close to what we see in the model. So that increases our confidence for the overall time series from 1979 to the present."

Arctic sea ice is shrinking and thinning at the same time, Schweiger explained, so it's normal for the summer ice volume to drop faster than the area covered, which today is about half of what it was in 1980.

Schweiger cautioned that past trends may not necessarily continue at the same rate, and predicting when the Arctic might be largely ice-free in summer is a different question. But creating a reliable record of the past helps to understand changes in the Arctic and ultimately helps to better predict the future.

"One question we now need to ask, and can ask, is what are the processes that are driving these changes in the ice? To what degree is it ocean processes, to what degree is this in the atmosphere?" Schweiger said. "I don't think we have a good handle on that yet."

The UW system was created by co-author Jinlun Zhang, an oceanographer at the Applied Physics Laboratory. The UW portion of the research was funded by NASA and the Office of Naval Research.

Other co-authors are first author Seymour Laxon, Katharine Giles, Andy Ridout, Duncan Wingham and Rosemary Willatt at University College London; Robert Cullen and Malcolm Davidson at the European Space Agency; Ron Kwok at NASA's Jet Propulsion Laboratory; Christian Haas at York University in Canada; Stefan Hendricks at the Alfred Wegener Institute for Polar and Marine Research in Germany; Richard Krishfield at Woods Hole Oceanographic Institution; Sinead Farrell at the University of Maryland; and Nathan Kurtz at Morgan State University in Baltimore.


Story Source:

The above story is based on materials provided by University of Washington. The original article was written by Hannah Hickey. Note: Materials may be edited for content and length.


Journal Reference:

  1. Seymour W. Laxon, Katharine A. Giles, Andy L. Ridout, Duncan J. Wingham, Rosemary Willatt, Robert Cullen, Ron Kwok, Axel Schweiger, Jinlun Zhang, Christian Haas, Stefan Hendricks, Richard Krishfield, Nathan Kurtz, Sinead Farrell, Malcolm Davidson. CryoSat-2 estimates of Arctic sea ice thickness and volume. Geophysical Research Letters, 2013 DOI: 10.1002/grl.50193

Cite This Page:

University of Washington. "Arctic Ocean is on thin ice: European satellite confirms numbers." ScienceDaily. ScienceDaily, 13 February 2013. <www.sciencedaily.com/releases/2013/02/130213105009.htm>.
University of Washington. (2013, February 13). Arctic Ocean is on thin ice: European satellite confirms numbers. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2013/02/130213105009.htm
University of Washington. "Arctic Ocean is on thin ice: European satellite confirms numbers." ScienceDaily. www.sciencedaily.com/releases/2013/02/130213105009.htm (accessed September 23, 2014).

Share This



More Earth & Climate News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

Hundreds of Thousands Hit NYC Streets to Protest Climate Change

AFP (Sep. 22, 2014) Celebrities, political leaders and the masses rallied in New York and across the globe demanding urgent action on climate change, with organizers saying 600,000 people hit the streets. Duration: 01:19 Video provided by AFP
Powered by NewsLook.com
Raw: Protesters Stage Wall Street Climate Sit-in

Raw: Protesters Stage Wall Street Climate Sit-in

AP (Sep. 22, 2014) A day after over 100,000 people marched against climate change, more than 1,000 activists blocked parts of Manhattan's financial district. Over 100 people, including a person wearing a white polar bear suit, were arrested Monday night. (Sept. 22) Video provided by AP
Powered by NewsLook.com
French FM Urges 'powerful' Response to Global Warming

French FM Urges 'powerful' Response to Global Warming

AFP (Sep. 22, 2014) French Foreign Minister Laurent Fabius on Monday warned about the potential "catastrophe" if global warming was not dealt with in a "powerful" way. Duration: 01:08 Video provided by AFP
Powered by NewsLook.com
Ongoing Drought, Fighting Put Somalia at Risk of Famine

Ongoing Drought, Fighting Put Somalia at Risk of Famine

AFP (Sep. 22, 2014) After a year of poor rains and heavy fighting Somalia is again at risk of famine, just three years after food shortages killed 260,000 people. Duration: 01:10 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins