sail-world.com
 
 
News Home Cruising Australia Cruising USA Cruising Canada Boats for Sale Sail-World Racing Photo Gallery FishingBoating
Video Gallery Newsletters
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



Flags at Sea, an infographic by John Tissott by Anna Parker and the Sail-World Team,














Lobster Thermidor - Making Julia proud by Greg Nicoll with Andy Adams and John Armstrong,




Our new Cruising Editor editor remembers his first offshore adventure by David Schmidt, Sail-World Cruising Editor, Seattle, WA








All Points Rally departs this November by Island Cruising Association New Zealand,


World ARC 2014 reaches Australia by World Cruising Club,


Venezuelan Port Control lift recent port restrictions. by Caribbean Safety and Security Net,


Seismic survey ship operating north of Aruba and Curacao by Caribbean Safety and Security Net,


A Mooring in Iceberg Alley by Rebecca Jackson,




Predictwind helps you pick the best time to depart by Richard Gladwell Sail-World.com/nz,






















4.8 million Legos all at sea by Adam Clark Estes,




Tranquil, colourful and funky, Genoa Bay is a must stop for West Coast *Feature
Scientist pioneered tracer to reveal hidden ocean flows
CYC Race to Mackinac - Cruising fleet sets sail in 106th edition
Dredging activity near corals can increase frequency of diseases
World ARC heading out of the Pacific
European Commission to take UK to court over red diesel
Understanding the Ocean's role in Greenland Glacier melt
Desolation Sound added to Salish Sea Pilot free cruising guides
Three Defensive Docking Strategies for Sailors
Revealing report on Search for American yacht Nina released *Feature
PredictWind's Weather Routing opens your navigation options - try it!
Sail-World Cruising Founding Editor Nancy Knudsen says farewell
Book review: Weather - you like it or not
Vaavud launches generation 2 wind meter
The drama begins - North West Passage sailors rescued from ice
Entering an unfamiliar bay - decision time
Baby Nemos finding their way home
High Latitude Sailing - Book of the Week
Will the Olympics make a difference to Rio pollution? *Feature
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   
Vestas Sailrocket 3 - Over the Horizon   
BoatUS speaks out about 'Ethanol-at-all-cost Agenda'   
Tidal current installations will increase boating hazards   
Eco-Sailboat of the future - Catherine Chabaud at work   
The final touch - which wax should I use on my boat?   
ARC Baltic sets sail to discover Europe's 'east sea'   
Another boom death. Australian sailor dies, hit by swinging boom   
Galley Guru vital to the life of the cruising sailor   
'Boat Handling in Marinas' by Rob Gibson - and how to get it reliably   
Heart-stopping moment as whale capsizes Zodiac   
If we stop killing parrotfish we can bring back Caribbean coral reefs   


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 NH
LocalAds   DE  ES  FR  IT