Featured Research

from universities, journals, and other organizations

Pondering A Climate Conundrum In Antarctica; Unique, Distinct Cooling Trend Discovered On Earth's Southernmost Continent

Date:
January 14, 2002
Source:
National Science Foundation
Summary:
Antarctica overall has cooled measurably during the last 35 years – despite a global average increase in air temperature of 0.06 degrees Celsius during the 20th century – making it unique among the Earth’s continental landmasses, according to a paper published in the online version of Nature.

Antarctica overall has cooled measurably during the last 35 years – despite a global average increase in air temperature of 0.06 degrees Celsius during the 20th century – making it unique among the Earth’s continental landmasses, according to a paper just published in the online version of Nature.

Researchers with the National Science Foundation (NSF) Longterm Ecological Research (LTER) site in Antarctica’s Dry Valleys – a perpetually snow-free, mountainous area adjacent to McMurdo Sound – argue in the paper that long-term data from weather stations across the continent, coupled with a separate set of measurements from the Dry Valleys, confirm each other and corroborate the continental cooling trend.

“Our 14-year continuous weather station record from the shore of Lake Hoare reveals that seasonally averaged surface air temperature has decreased by 0.7 degrees Celsius per decade,” they write. “The temperature decrease is most pronounced in summer and autumn. Continental cooling, especially the seasonality of cooling, poses challenges to models of climate and ecosystem change.”

The findings are puzzling because many climate models indicate that the Polar regions should serve as bellwethers for any global warming trend, responding first and most rapidly to an increase in temperatures. An ice sheet many kilometers thick in places perpetually covers almost all of Antarctica.

Temperature anomalies also exist in Greenland, the largest ice sheet in the Northern Hemisphere, with cooling in the interior concurrent with warming at the coast.

Peter Doran, of the University of Illinois at Chicago, the lead author of the paper, and his co-authors, acknowledge that other studies conducted in Antarctica have deduced a warming trend elsewhere in the continent. But they note that the data indicate that the warming occurred between 1958 and 1978. They also note that the previous claims that Antarctic is warming may have been skewed because the measurements were taken largely on the Antarctic Peninsula, which extends northwards toward South America. The Peninsula itself is warming dramatically, the authors note, and there are many more weather stations on the peninsula than elsewhere on the continent.

Averaging the temperature readings from the more numerous stations on the Peninsula has led to the misleading conclusion that there is a net warming continent-wide. “Our approach shows that if you remove the Peninsula from the dataset, and look at the spatial trend. The majority of the continent is cooling,” said Doran.

He added that documentation of the continental cooling presents a challenge to climate modelers. “Although some do predict areas of cooling, widespread cooling is a bit of a conundrum that the models need to start to account for,” he said."

The Dry Valleys are the largest ice-free area in Antarctica, a desert region that encompasses perennially ice-covered lakes, ephemeral streams, arid soils, exposed bedrock and alpine glaciers. All life there is microscopic.

The team argues that the cooling trend could adversely affect the unique ecosystems in the region, which live in a niche where a delicate balance between freezing and warmer temperatures allows them to survive and where liquid water is only available during the very brief summer. They argue that a net cooling of the continent could drastically upset that balance.

“We present data from the Dry Valleys representing the first evidence of rapid terrestrial ecosystem response to climate cooling in Antarctica, including decreased lake primary productivity and declining soil invertebrates,” they write.

Their data, they argue, are “the first to highlight the cascade of ecological consequences that result from the recent summer cooling.”


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Pondering A Climate Conundrum In Antarctica; Unique, Distinct Cooling Trend Discovered On Earth's Southernmost Continent." ScienceDaily. ScienceDaily, 14 January 2002. <www.sciencedaily.com/releases/2002/01/020114073549.htm>.
National Science Foundation. (2002, January 14). Pondering A Climate Conundrum In Antarctica; Unique, Distinct Cooling Trend Discovered On Earth's Southernmost Continent. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2002/01/020114073549.htm
National Science Foundation. "Pondering A Climate Conundrum In Antarctica; Unique, Distinct Cooling Trend Discovered On Earth's Southernmost Continent." ScienceDaily. www.sciencedaily.com/releases/2002/01/020114073549.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) 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