sail-world.com
 
 
News Home Boats for Sale MarineBusiness-World Sail-World Racing Cruising Int Magnetic Is RW Photo Gallery FishingBoating
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.







Sail-World Cruising News - local and the World













4.8 million Legos all at sea by Adam Clark Estes,












In search of the Duroc by Jack Binder, Coral Sea




Dredging activity near corals can increase frequency of diseases by ARC Centre of Excellence Coral Reef Studies,




Understanding the Ocean's role in Greenland Glacier melt by Woods Hole Oceanographic Institution (WHOI),


Dangerous conditions for boating on entire NSW Coast by Transport Roads and Maritme Services,


Three Defensive Docking Strategies for Sailors by Captain John Jamieson, Florida


Revealing report on Search for American yacht Nina released *Feature by Rob Kothe and the Sail-World team,








AYSS PacificNet/Tahiti voted a success! by Asia Pacific Superyachts,














Baby Nemos finding their way home by ARC Centre of Excellence Coral Reef Studies,






Blue Planet Odyssey, around world rally, begins
Africa Europe Cruising Challenge now open for entries
The real ‘Supermoon’ story
Warm and noisy welcome for Oceans of Hope in La Rochelle
Sailor rescued after Facebook call for rescue
Solo sailing star's passion = busy environmental schedule
El Niño (Part 2). Effects on the Pacific Ocean
Northern Scotland: Voyage to Orkney and Shetland Isles (Part 1)
Northern Scotland: Voyage to Orkney and Shetland Isles, photos
The Galley Guys' favourite shrimp recipe
Dangerous conditions forecast for NSW boaters
Vestas Sailrocket 3 - Over the Horizon
Rescued sailors reach shore after dramatic ocean rescue
Yacht abandoned 170nm north of New Zealand, navigation warning out
Tidal current installations will increase boating hazards
Abell Point Marina looking shipshape
Dangerous conditions for NSW coastal boaters from Thursday
Oceanis 48 at the Sydney International Boat Show
Eco-Sailboat of the future - Catherine Chabaud at work
Calling yachts in the South Pacific - rally to New Zealand
The final touch - which wax should I use on my boat?   
ARC Baltic sets sail to discover Europe's 'east sea'   
Auckland On Water Boat Show to hold world record attempt   
Another boom death. Australian sailor dies, hit by swinging boom   
Galley Guru vital to the life of the cruising sailor   
Auckland Cruisers - seminar on cruising sails   
'Boat Handling in Marinas' by Rob Gibson - and how to get it reliably   
Heart-stopping moment as whale capsizes Zodiac   
Lessons from the West: Great Barrier Reef in danger   
Climate change could stop fish finding their friends   
Vanuatu ups their welcome to cruising sailors with new approach   
Criminal charges mooted for owners of sunk HMS Bounty   
Yachting Australia announces resignation of CEO Phil Jones   
Red faces after authorities inadvertently aid boat thief to get away   
Mobiles drive traffic - 72% increase in Sail-World.com page view *Feature   
New import permit for Mexico resolves impound problems   
Captain Phillips and Obama admin wants pirates' nests eradicated   
Sail Estonia: a VERY new idea   
Tie This 'Lifesaving' Bowline in Seconds - the easy way!   
A Beer Bummel on the Thames River   


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 NEW Cru SH
LocalAds   DE  ES  FR  IT