Featured Research

from universities, journals, and other organizations

Rising Antarctic snowmelt forcast

Date:
December 3, 2009
Source:
City College of New York
Summary:
The 30-year record low in Antarctic snowmelt that occurred during the 2008-09 austral summer was likely due to concurrent strong positive phases for two main climate drivers, ENSO (El Nino, Southern Oscillation) and SAM (Southern Hemisphere Annular Mode), according to earth and atmospheric scientists.

The 30-year record low in Antarctic snowmelt that occurred during the 2008-09 austral summer was likely due to concurrent strong positive phases for two main climate drivers, ENSO (El Niño -- Southern Oscillation) and SAM (Southern Hemisphere Annular Mode), according to Dr. Marco Tedesco, Assistant Professor of Earth & Atmospheric Sciences at The City College of New York.

Professor Tedesco, who is also on the doctoral faculty at the CUNY Graduate Center, added that Antarctic snowmelt levels should revert to higher norms as one of the drivers, the SAM, subsides as the damage to the ozone layer is repaired. His conclusions, which are based on space-borne microwave observations between 1979 and 2009, were reported in Geophysical Research Letters earlier this fall.

"The study's goal was not only to report on melting but also on the relationship between melting and the climate drivers, El Niño and the SAM," he explained. Low melt years during the 1979-2009 satellite record are related to the strength of the westerly winds that encircle Antarctica, known as the Southern Hemisphere Annular Mode (SAM).

"When the SAM is in a positive phase -- meaning that the belt of winds is stronger than average -- it has a cooling effect on Antarctic surface temperatures," he explained. "The SAM was especially strong in austral spring and summer 2008-2009, and subsequently the 2008-2009 snowmelt was lower than normal."

During the past 30-40 years, the SAM has gradually strengthened during austral summer, due mainly to human-caused stratospheric ozone depletion, he continued. However, as the hole is repaired as a result of compliance with the Montreal protocol, the winds will weaken and Antarctica will be subject to more warming air.

The increasing summer SAM trends are projected to subside, he added. "It is likely that summer temperature increases over Antarctica will become stronger and more widespread because the warming effect from greenhouse gas increases will no longer be kept by the weakened circumpolar winds. The bottom line is as the ozone layer recovers we'll likely have more melting on Antarctica."

According to Professor Tedesco, variability in El Niño and the SAM account for up to 50 percent of the variations in Antarctic snowmelt. However, the melting trends over the whole continent derived from satellite data are not statistically significant, he noted.

"If you add one year of data, the trend could shift from positive to negative or vice versa. Thirty years is not enough to tell the overall trend for Antarctica." However, he noted that studies based on land observations with data going back to the 1950s support a warming trend, especially on the Antarctic Peninsula.


Story Source:

The above story is based on materials provided by City College of New York. Note: Materials may be edited for content and length.


Cite This Page:

City College of New York. "Rising Antarctic snowmelt forcast." ScienceDaily. ScienceDaily, 3 December 2009. <www.sciencedaily.com/releases/2009/12/091203101420.htm>.
City College of New York. (2009, December 3). Rising Antarctic snowmelt forcast. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2009/12/091203101420.htm
City College of New York. "Rising Antarctic snowmelt forcast." ScienceDaily. www.sciencedaily.com/releases/2009/12/091203101420.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

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
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) — A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 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:
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