Featured Research

from universities, journals, and other organizations

New Study Shows Early Signals Of Climate Change In Earth's Cold Regions

Date:
December 17, 2001
Source:
University Of Colorado At Boulder
Summary:
Global mean temperatures have risen one degree Fahrenheit over the past 100 years, with more than half of the increase occurring in the last 25 years, according to University of Colorado at Boulder Senior Researcher Richard Armstrong.

Global mean temperatures have risen one degree Fahrenheit over the past 100 years, with more than half of the increase occurring in the last 25 years, according to University of Colorado at Boulder Senior Researcher Richard Armstrong.

"As slight as that may seem, it’s enough to make a difference," said Armstrong, who is affiliated with the National Snow and Ice Data Center headquartered at CU-Boulder. "Now, long-term monitoring of a series of cold region, or cryospheric, parameters shows that for several decades the amounts of snow and ice around the world have been decreasing."

To assemble the big picture, the NSIDC, commemorating 25 years of service, has organized a special session at the 2001 Fall Meeting of AGU, "Monitoring an Evolving Cryosphere." The session begins Tuesday, Dec. 11, and extends through Thursday afternoon, with 75 contributions from all areas of cryospheric study. Papers and posters include examinations of lake and river ice, glacier dynamics and mass ice balance studies in polar and continental glaciers, regional and polar snow cover trends and variations of Canadian ice cap elevation changes.

In the world of climate change, trends are most readily observed in the Earth’s cold regions, where the sensitivity of ice and snow to temperature changes serves as an early indicator of even relatively small differences, he said. Today’s receding and thinning sea ice, mountain glacier mass losses, decreasing snow extent, melting permafrost and rising sea level are all consistent with warming.

Although Arctic sea ice extent is decreasing by about 3 percent per decade, the trends are not uniform. While recent studies have indicated that the ice thickness also had decreased over several decades, new information shows that the ice may have thinned rapidly, Armstrong said.

Examination of springtime ice thickness in the Arctic Ocean indicates that the mean ice thickness decreased 1.5 meters between the mid-1980s and early 1990s.

"We attribute at least some of the thinning to changes in Arctic atmosphere and ice circulation patterns. While no similar trend was evident in ice thickness near the North Pole, the data unquestionably indicate a decrease in total ice volume in the western Arctic Ocean," said Walter B. Tucker, of the Army Cold Regions Research and Engineering Laboratory in Hanover, N.H.

"At low latitudes, glacial changes are pronounced, uncontested and solid evidence of climate warming," said Eric Rignot, a researcher at the Radar Science and Engineering Section of NASA’s Jet Propulsion Laboratory. "But what is happening in the polar ice sheets is less clear.

"My study shows that a number of areas previously believed to be gaining mass in the Antarctic are in fact close to being balanced or even losing mass. The only area which stands out as clearly out of balance is the Amundsen Sea sector of Antarctica drained by the Pine Island and Thwaites glaciers."

There are other lines of evidence - besides the mass budget calculations - that the region is undergoing rapid changes. These include where the ice leaves the continent and begins to float, as well as ice thinning and flow acceleration. In the remainder of Antarctica, it is too soon to say, said Rignot.

"We now know that the retreat of the Pine Island, Thwaites and Smith glaciers was due to a widespread thinning of ice that extended from their termini to over 200 kilometers inland," said Andrew Shepherd of the Centre for Polar Observation and Modeling at University College London.

These glaciers are the principal ice drainage channels for the Amundsen Sea sector of the West Antarctic Ice Sheet. According to Shepherd, between 1991 and 2001 the Pine Island, Thwaites and Smith glaciers thinned by more than 15, 25 and 45 meters respectively where they leave the continent and begin to float, losing a total of 157 cubic kilometers of ice to the ocean. At that rate, Shepherd projects that the glaciers could begin to float within 150 years.

Besides these observations, changes within other cryospheric areas will be reported on at the meeting. They include papers on mountain glacier monitoring, Canadian snow cover, results of river ice monitoring, changes in onset of Arctic snow melt dates, and variations in snow accumulation over northern Eurasia and their connections to the Atlantic and Pacific Oceans.

The NSIDC welcomes members of the press to its 25th Anniversary Icebreaker Reception, Tuesday, Dec. 11, from 5 p.m. to 8 p.m. in Room 220 on the east side of the Mezzanine Level. The evening is hosted by the Arctic Institute of North America, the Arctic Research Consortium of the United States and the NSIDC and Permafrost Section of AGU.

For more information, see State of the Cryosphere on the Web at: http://nsidc.org/sotc/. NSIDC is part of the Cooperative Institute for Research in Environmental Sciences, a joint venture of CU-Boulder and the National Oceanic and Atmospheric Administration.


Story Source:

The above story is based on materials provided by University Of Colorado At Boulder. Note: Materials may be edited for content and length.


Cite This Page:

University Of Colorado At Boulder. "New Study Shows Early Signals Of Climate Change In Earth's Cold Regions." ScienceDaily. ScienceDaily, 17 December 2001. <www.sciencedaily.com/releases/2001/12/011210163124.htm>.
University Of Colorado At Boulder. (2001, December 17). New Study Shows Early Signals Of Climate Change In Earth's Cold Regions. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2001/12/011210163124.htm
University Of Colorado At Boulder. "New Study Shows Early Signals Of Climate Change In Earth's Cold Regions." ScienceDaily. www.sciencedaily.com/releases/2001/12/011210163124.htm (accessed August 21, 2014).

Share This




More Earth & Climate News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California Drought Stings Honeybees, Beekeepers

California Drought Stings Honeybees, Beekeepers

AP (Aug. 21, 2014) — California's record drought is hurting honey supplies and raising prices for consumers. The lack of rainfall means fewer crops and wildflowers that provide the nectar bees need to make honey. (Aug. 21) Video provided by AP
Powered by NewsLook.com
Thousands Of Species Found In Lake Under Antarctic Ice

Thousands Of Species Found In Lake Under Antarctic Ice

Newsy (Aug. 20, 2014) — A U.S. team found nearly 4,000 species in a subglacial lake that hasn't seen sunlight in millennia, showing life can thrive even under the ice. Video provided by Newsy
Powered by NewsLook.com
Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) — Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) — Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
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:
from the past week

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