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



Where in the world are our strongest corals? by Hanny Rivera - Cohen's Lab,






Barnacle Busting by Neil and Ley Langford,




Polar research: Six priorities for Antarctic science by Mahlon C. Kennicutt II and colleagues,




































Risks to penguin populations continues by British Antarctic Survey,






Follow these tips when anchoring by Alex and Daria Blackwell,








Galley Guys meet the Spice Lady by Greg Nicoll, Andy Adams and John Armstrong,




Baltic 4 Nations rally is now in full swing
Royal Prince Alfred Yacht Club’s Jack Gale training centre born
Multihull Central launches Aquila range at SIBS *Feature
If all else fails read the instructions!!
ARC Baltic fleet cruising and anchoring in the Finnish archipelago
Phuket Yacht Show: new kid on the block taking on PIMEX? *Feature
Endangered species are like Movie Stars - Charlie Sheens and Tom Hanks
Vanuatu Customs making life easier for visiting cruising yachts
Multihull Central - Covering all the bases *Feature
Flags at Sea, an infographic by John Tissott
Cruising lessons from ocean racers
Sydney International Boat Show - Day 2 *Feature
Marine Rescue volunteers celebrate new unit and $120,000 vessel
Procedures set out for waterborne visitors to Vanuatu
17-year-old RNLI volunteer saves child in first rescue mission + Video
Teen names latest RNLI Shannon class lifeboat in Poole + Video
Fascinating opportunity with OceansWatch
Pantaenius Insurance - being seen in yellow, green and orange *Feature
Fake GPS signals detected when cruising the high seas
Sydney International Boat Show - Changed conditions on Sydney Harbour
Our new Cruising Editor editor remembers his first offshore adventure   
World Odyssey Race - Bringing back the Corinthian spirit   
Blue Planet Odyssey Rally - Raising climate change awareness   
Pacific Circuit Rally - 2015   
All Points Rally departs this November   
Gold Coast Broadwater no closer to welcoming supermaxis *Feature   
2014 Magnetic Island Race Week Cruising North - One for Poppy? *Feature   
World ARC 2014 reaches Australia   
A Mooring in Iceberg Alley   
Marine Rescue volunteers called to rescue out of fuel vessel updates   
Marine Rescue volunteers called to rescue second vessel out of fuel   
Boaters urged to speak up on 15%ethanol proposal   
Predictwind helps you pick the best time to depart   
Silver Gull Creek host Marion Smart: Funeral and Wake   
IMB reports worrying trend of piracy hijacks in Southeast Asia   
Watch this whale lift a Kayak clear out of the water   
World ARC reaches half-way point in Australia   
Northern Scotland: Voyage to Orkney and Shetland Isles (Part 2) *Feature   
Vietnam Marina Development: ONE°15 Vung Ro Bay Marina Resort   
Marine Rescue volunteers praised for saving six from yacht   


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 Cru SH
LocalAds   DE  ES  FR  IT