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



































ISAF Sailing World Championships - Watch medal races live here by Dan Ibsen, Sail-World Europe & UK editor,








470 Men and Women Worlds - Vadlau and Ogar into pole position by 470 International Association Class,




ISAF Sailing Worlds, Santander - Strong competition for RS:X fleets by Olga Maslivets, International RS:X Class Assoc.,




















Volvo Ocean Race: Win a stopover trip by designing an ECsix T-Shirt
Red Bull 49erFX: On the eve of the Worlds in Santander
America's Cup: Ben Ainslie Racing launches partnership with Yamaha
2014 Chicago Match Cup - Starts tomorrow
Rio 2016 Daylight the issue for Olympic sailing regatta
ISAF Sailing World Championships - USA 470's and Lasers battle at top
ISAF Sailing World Championships - Santander - Day 5 video highlights
ISAF Sailing World Championships - Santander images by Jesús Renedo
PWA Cold Hawaii World Cup - No action on day 2
470 Men and Women Worlds - Game on for Olympic Qualification
ISAF Sailing World Championships: Finns off to slow start in Santander
ISAF Sailing World Championships - Seesaw Day 5 in Santander + Video
ISAF Sailing World Championships - 470 sailors shine in Santander
Royal Cup Marina Ibiza - Kiwi Ray Davies returns to TP52 fleet
Starboard Hatteras Wave Jam - No windsurfing action on day 1
A complete recap of the most successful Melges 20 World Championship
Rolex Big Boat Series - Prizegiving images by Chuck Lantz
ISAF Santander - Upwards path for Austrian women's 470 crew + video
18ft skiffs: Carnage compilation from the glory days of the Grand Prix
ISAF Worlds: Video from the British Sailing Team
Bart's Bash expected to set new records this weekend   
PWA Cold Hawaii World Cup - Marcilio Browne wins Super Session   
470 Men and Women World Championships - Racing abandoned on day 2   
ISAF Sailing World Championships - Day 4 images from Santander   
ISAF Sailing Worlds, Santander: Emerging Nations Program sailors shine   
ISAF Sailing Worlds, Santander - Teasing winds play havoc on day 4   
ISAF Sailing World Championships: Hot conditions in Santander on day 4   
Santander ISAF Sailing World Championships joins Bart’s Bash   
PWA Cold Hawaii World Cup - Grounded fishing boat creates problems   
Marseille One Design - GC32 Armin Strom Sailing Team emerge victorious   
Rolex Big Boat Series 2014 - Ready for another 50 years   
2014 Rolex Big Boat Series - Farr 40 Day 4   
2014 Rolex Swan Cup - Eleventh-hour victories   
Extreme Sailing Series - Kiwis clinch Act win in Istanbul + Video   
2014 Rolex Big Boat Series - Two long races today for the J70 fleet   
2014 Rolex Big Boat Series - Impressive to sail out of the Golden Gate   
Extreme Sailing Series - Istanbul delivers four days of great racing   
ISAF Sailing Worlds Santander - Day 3 images by Sail-World.com   
Extreme Sailing Series: Emirates Team NZ bounces back for series win   
Santander 2014 ISAF Worlds - Light winds and current test six classes   


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