sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery
Sail-World.com : Planning a sail to the Antarctic any time soon? - check this out!
Planning a sail to the Antarctic any time soon? - check this out!


'Antarctic sea ice'    . ©    Click Here to view large photo

While global warming may be making it easier to sail the Northwest Passage and in Arctic regions generally, the same global warming might, paradoxically, make it more difficult to sail in Antarctic regions.

In an apparent polar paradox, global warming has led to more ice in the sea around Antarctica and could help insulate the southern hemisphere from atmospheric warming.


A Dutch study says that unlike in the Arctic region, sea ice around Antarctica has expanded at a significant rate since 1985.

Scientists have known for several years that meltwater from ice sheets can form a cold, fresh layer on the ocean surface that protects sea ice from the warmer waters below. But they were not sure whether that aided the observed expansion of Antarctic sea ice as the new study suggests.

Published online in Nature Geoscience, the article suggests cool freshwater from melt beneath the Antarctic ice shelves has insulated offshore sea ice from the warming ocean beneath.

Richard Bintanja of the Royal Netherlands Meteorological Institute and colleagues say the Antarctic sea ice expands during southern hemisphere autumn and winter in response to this fresh, cool surface layer that freezes easily.

'Against the background of global climate warming, the expansion of Antarctic sea ice is an exceptional feature, which seems to be associated with decreasing sea surface temperatures in the Southern Ocean,' they write.

'We predict that this mechanism will be a sizable contributor to the factors that regionally and seasonally offset greenhouse warming and the associated sea ice retreat.'

They say the expanding sea ice may constitute a 'feedback' that has the potential to oppose southern hemisphere atmospheric warming and amplify increases in global sea level.

Changes in sea ice can significantly modulate climate change because of its high reflective and strong insulating nature, the paper says.

There are other plausible explanations for Antarctic sea-ice expansion, however.

'The mechanism could be completely true, but this study does not demonstrate that increased melting has made a significant contribution to the increase in sea-ice cover,' says Paul Holland, an ocean modeller at the British Antarctic Survey in Cambridge, UK, who last year co-authored a study showing that the sea-ice expansion is caused in large part by regional wind patterns.

Winds change the extent of sea ice, both by physically moving the ice and by warming or cooling the sea surface. Using satellite data for sea-ice motion in 1992–2010, Holland and his colleague Ron Kwok, a climate researcher at NASA's Jet Propulsion Laboratory in Pasadena, California, showed that in certain regions of Antarctica, such as the Weddell Sea, sea-ice changes are almost entirely due to the physical force of the winds. In other areas, such as the King Håkon Sea, they result from the combined effects of wind force and temperature.

Bintanja says that wind effects are important locally but that meltwater influences sea-ice expansion regionally. Holland counters that ice melt is not uniform around the Antarctic coastline — as assumed by the authors of the latest study — but is concentrated in certain locations. Holland says that both wind patterns and meltwater may be expanding the sea-ice near the South Pole, but that remains to be seen.

More at http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1767.html


by Media Services

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=107995

6:17 AM Mon 1 Apr 2013GMT


Click here for printer friendly version
Click here to send us feedback or comments about this story.







News - USA and the World























International Moth Worlds: Rashley ahead as Aussies close in by Mark Jardine / YachtsandYachting.com,




















International Moth Worlds - Mothballed on day 4 + Video by Mark Jardine / YachtsandYachting.com,




Gladwell's Line: A change of direction needed in the America's Cup *Feature by Richard Gladwell/Sail-World.com/nz,




















PWA Pozo World Cup - Fantastic finale determines winners
Six Metre Class British Open Championship - Llanoria and Valhalla win
Anna Tunnicliffe set to compete at the CrossFit Games
America's Cup: Oracle Team USA holds foiling camp at Wangi SC
Volvo Ocean Race: Abu Dhabi OR completes double Atlantic crossing
Volvo Ocean Race: Team SCA has a 'pull through day' off the Canaries
No tiller sailing - how to steer using just the sails + Video
International Moth Worlds: Three bullets in a row for Greenhalgh
U.S. Junior Women’s Singlehanded Championship - Sophia Reineke wins
BIC Techno 293 Worlds 2014 - Day 0 Opening
Fuerteventura World Cup - Slalom action highlights day 2
2014 Governor's Cup - Sam Gilmour of RFBYC victorious again
Farr 40 West Coast Champ - Skipper Alberto Rossi leads Enfant Terrible
Flying Dutchman World Championships - Magyars are the Masters
Final day shakes up standings at Cape Panwa Hotel Phuket Raceweek
2014 -15 Volvo Ocean Race: Team Alvimedica pushing towards Southampton
NYYC Race Week - Saving the best for last
VX One North American Championship - Chris Alexander commands
2014 Cape Panwa Hotel Phuket Raceweek - Waiting game on Day 3
International Moth Worlds: Thunderstorms delay racing on Day 1
Fuerteventura World Cup - Impressive tricks on day 1   
2014 Governor's Cup - Two former winners in the finals   
America's Cup: Iain Murray explains reasons for Australian withdrawal *Feature   
Wilson and Roble remain number one match racers in U.S.   
2014 ISAF Youth Match Racing World Championship - Set to start   
PWA Pozo World Cup - Moreno twins dominate home spot   
ISAF Youth Worlds - Record breaking regatta in Tavira + Video   
Melges 32 European Championship - Robertissima remains out front   
Farr 40 West Coast Championship - Italians take one-point lead   
Melges 32 European Championship - Day 3 images by Carlo Borlenghi   
New York Yacht Club Race Week - Marstrom 32 fleet off to anxious start   
Melges 32 European Championship - Day 3 images by Max Ranchi   
CYC Race to Mackinac - Cruising fleet sets sail in 106th edition   
Team Alvimedica getting a touchup   
PWA Pozo World Cup - Plenty of drama on day 5   
ISAF Youth Sailing World Championship - Day 5 Videos   
NYYC Race Week - High performance classes put on shoreside show   
2014 Pacific Cup - 'Invisible Hand' the first boat to finish   
Clipper Round the World Yacht Race - B.C.'s Eric Holden skippers wins   
America's Cup: Updates on Team Australia withdraw   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL WAS US
LocalAds   DE  ES  FR  IT