Featured Research

from universities, journals, and other organizations

Miniature Lab Ice Spikes May Hold Clues To Warming Impacts On Glaciers

Date:
March 6, 2007
Source:
University of Colorado at Boulder
Summary:
Tiny lab versions of 12-foot tall snow spikes that form naturally on some high mountain glaciers may someday help scientists mitigate the effects of global warming in the Andes, according to a University of Colorado at Boulder professor.

Ice penitentes in Andes.
Credit: Image courtesy Javier Corripio, Federal Institute of Technology, Zurich

Tiny lab versions of 12-foot tall snow spikes that form naturally on some high mountain glaciers may someday help scientists mitigate the effects of global warming in the Andes, according to a University of Colorado at Boulder professor.

CU-Boulder physics Assistant Professor Meredith Betterton said the spikes, known as penitentes, are shaped when concentrated rays of sunlight evaporate snow from low spots on glacier fields in a process known as sublimation. The lab studies confirm that the low spots, or troughs, deepen as intense sunlight strikes them, sculpting penitentes by the hundreds of thousands on some glaciers, she said.

Some scientists have predicted that penitentes might help put the brakes on shrinking glaciers in a warming climate by blocking sunlight that might otherwise be absorbed by glacial surfaces, said Betterton. She gave a presentation on penitentes at the March Meeting of the American Physical Society in Denver March 5-9, which hosted more than 7,000 scientists.

"The key piece of physics here is that the dips in the snow absorb more reflected light, which drops the snow height and helps to form the penitentes," she said. "One big question is how penitentes will fare in a warming world."

Betterton, along with colleagues Vance Bergeron and Charles Berger from Ecole Normale Superieure research laboratories in Paris, sprouted miniature penitentes in the lab to better understand the physics behind their formation. Penitentes -- named for their resemblance to a procession of white-hooded monks -- were first described by naturalist Charles Darwin during an expedition to South America he and his crew made in 1835 aboard his ship, the Beagle.

The research team put a block of snow in a horizontal freezer in Paris filled with water vapor and chilled with liquid nitrogen, covered it with a clear Plexiglas lid, and shined a spotlight on the snow to simulate sunlight, Betterton said. Tiny snow spikes up to two inches high formed within a few hours, apparently by the same process through which penitentes form naturally on alpine glaciers, she said.

The study confirmed previous theories that penitentes grow when sunlight in cold, dry air in the high mountains strikes snow patches and transforms them directly into water vapor, she said. Mathematical models developed by Betterton indicate microscopic penitentes begin merging with each other, or "coarsening," early in the sublimation process, growing both taller and wider over time.

The research has applications for understanding and even mitigating global warming, since Andean penitentes shade large areas of glacial surfaces, possibly cooling them and slowing the rate of ice loss, she said. Some scientists believe warming temperatures could trigger the eventual destruction of vast fields of penitentes and hasten glacier melting, "which would be disastrous for Argentinean and Chilean regions that depend on runoff for water supplies," said Betterton.

Betterton and her colleagues took the research a step further, sprinkling the sprouting lab penitentes with a fine layer of carbon soot to simulate pollutants known to be accumulating on some glaciers around the globe. Such carbon-based pollutants have been found to increase melting rates on glaciers by causing the ice to absorb more sunlight and heat up, she said.

The team found that small amounts of soot sprinkled on the snow in the lab appeared to accelerate penitente formation. "One worry that scientists have is that without penitentes, some of these Andean glaciers will melt more quickly," she said. "It may well be that adding a small layer of dirt to the surface of these glaciers could help to preserve them."

The penitente research effort also has implications for the microelectronic industry, she said. Precisely shaped micro-penitentes formed by laser beams could lead to the development of solar energy cells that trap light more efficiently.

Betterton's research has been funded in part by the Alfred P. Sloan Foundation.


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. "Miniature Lab Ice Spikes May Hold Clues To Warming Impacts On Glaciers." ScienceDaily. ScienceDaily, 6 March 2007. <www.sciencedaily.com/releases/2007/03/070305140922.htm>.
University of Colorado at Boulder. (2007, March 6). Miniature Lab Ice Spikes May Hold Clues To Warming Impacts On Glaciers. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2007/03/070305140922.htm
University of Colorado at Boulder. "Miniature Lab Ice Spikes May Hold Clues To Warming Impacts On Glaciers." ScienceDaily. www.sciencedaily.com/releases/2007/03/070305140922.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