Antarctic Ice Discussion

[BornFromTheVoid]

I wonder how this is explained away ? Maximum extension 'explained' by freshwater and/or winds. Is it the wind or is it something else that keeps the mins so high??. Obviously not much interest in the media and a few googles keep bringing up the Artic, what's the theory behind these highest mins being recorded year on year.

Can there not just be an explanation with it having to be "explained away"? There have not been "highest mins" recorded year on year.

Seems the general thinking at the moment, is that the fresh water run-off from the melting ice shelves is contributing to the trend for increased sea ice there, as you can read about in knockers posts just a few above yours. Other possible contributors are increased westerlies around the continent and freshening of the water from increased precipitation.

There seems to be no clear cut answer yet thought.

[stewfox]

Seems the general thinking at the moment, is that the fresh water run-off from the melting ice shelves is contributing to the trend for increased sea ice there, as you can read about in knockers posts just a few above yours. Other possible contributors are increased westerlies around the continent and freshening of the water from increased precipitation.

There seems to be no clear cut answer yet thought.

For max makes sense but for mins ? ,although current ice concentration anomalies do show a pattern.. Have submitted question NISDC

[stewfox]

For max makes sense but for mins ? ,although current ice concentration anomalies do show a pattern.. Have submitted question NISDC

NISDC have got back to me and send they have forwarded the question to their ice scientists, which is nice. Will let you know.

[keithlucky]

Antartic 500 days above normal

http://arctic.atmos.uiuc.edu/cryosphere/timeseries.south.anom.1979-2008

[stewfox]

NISDC have got back to me and send they have forwarded the question to their ice scientists, which is nice. Will let you know.

 

I can't seem to cut and paste on this site but this is a response from Walt Meier research scientist for NISDC

Here is a response from Walt Meier at NSIDC.docx

[knocker]

Press Release - New insight into accelerating summer ice melt on the Antarctic Peninsula

A new 1000-year Antarctic Peninsula climate reconstruction shows that summer ice melting has intensified almost ten-fold, and mostly since the mid 20th Century. Summer ice melt affects the stability of Antarctic ice shelves and glaciers.

 

 

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=2126

[knocker]

The Paper

 

Acceleration of snow melt in an Antarctic Peninsula ice core during the twentieth century

Abstract  

Over the past 50 years, warming of the Antarctic Peninsula has been accompanied by accelerating glacier mass loss and the retreat and collapse of ice shelves. A key driver of ice loss is summer melting; however, it is not usually possible to specifically reconstruct the summer conditions that are critical for determining ice melt in Antarctic. Here we reconstruct changes in ice-melt intensity and mean temperature on the northern Antarctic Peninsula since AD 1000 based on the identification of visible melt layers in the James Ross Island ice core and local mean annual temperature estimates from the deuterium content of the ice. During the past millennium, the coolest conditions and lowest melt occurred from about AD 1410 to 1460, when mean temperature was 1.6 °C lower than that of 1981–2000. Since the late 1400s, there has been a nearly tenfold increase in melt intensity from 0.5 to 4.9%. The warming has occurred in progressive phases since about AD 1460, but intensification of melt is nonlinear, and has largely occurred since the mid-twentieth century. Summer melting is now at a level that is unprecedented over the past 1,000 years. We conclude that ice on the Antarctic Peninsula is now particularly susceptible to rapid increases in melting and loss in response to relatively small increases in mean temperature.

 

 

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo1787.html

[keithlucky]

James Ross Island ice core data here.

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/james-ross-island/

As usual, the data tells a different story than the news releases.

http://s23.postimg.org/iy0h7iqqj/James_Ross_Island_Ice_Core.png

 

[knocker]

That actually proves nothing. If you have read the actual paper, I don't have access to Nature Geoscience, I would be interested in why you disagree. Also BAS are not renown for releasing false information.

[keithlucky]

Heading for the record ice growth this winter in the Antarctic  http://sunshinehours.wordpress.com/tag/antarctic-sea-ice/

 

[ANYWEATHER]

Heading for the record ice growth this winter in the Antarctic  http://sunshinehours.wordpress.com/tag/antarctic-sea-ice/

Thanks for that. !   Really goes to show that most warmist ignore the Antarctic, but why? Antartica is the place to go to find out if our planet is warming or cooling, its the biggest block of ice on the planet and im sure is a Barometer of the planets temps. Surely if the planet was so called warming why is the Antarctic gaining in ice?

Edited April 27, 2013 by ANYWEATHER

[UV-RAY]

Heading for the record ice growth this winter in the Antarctic  http://sunshinehours.wordpress.com/tag/antarctic-sea-ice/

Wait until the new adjusted figures come in, they'll paint a different picture Im sure.

[BornFromTheVoid]

Heading for the record ice growth this winter in the Antarctic  http://sunshinehours.wordpress.com/tag/antarctic-sea-ice/

 

Not sure if I see signs on heading for record growth, but it's looking pretty good down there.

 

Thanks for that. !   Really goes to show that most warmist ignore the Antarctic, but why? Antartica is the place to go to find out if our planet is warming or cooling, its the biggest block of ice on the planet and im sure is a Barometer of the planets temps. Surely if the planet was so called warming why is the Antarctic gaining in ice?

 

I'd say you're thinking of the ice sheet, a very different beast to the sea ice. The biggest block of ice on this planet (the Antarctic Ice Sheet) is melting!

 

The barometer of the planet, as you called it, is melting. Does that change your opinion?

As for the sea ice, it's increasing despite warming. The main explanation is due to increased freshwater runoff from the ice sheet freshening the ocean water, which allows it to freeze at a higher temperature. Increased circumpolar westerlies, which drive the sea ice away from the coast. Either way, Antarctic sea ice growth is several times slower than Arctic sea ice loss.

 

Wait until the new adjusted figures come in, they'll paint a different picture Im sure.

 

I believe ye have a thread for yer conspiracy theories now. Best keep them in there

[knocker]

Thanks for that. !   Really goes to show that most warmist ignore the Antarctic, but why? Antartica is the place to go to find out if our planet is warming or cooling, its the biggest block of ice on the planet and im sure is a Barometer of the planets temps. Surely if the planet was so called warming why is the Antarctic gaining in ice?

 

Warmists ignore the Antarctic. What a ridiculous comment. BFTV has covered the runoff so I'll leave that.

 

Why Antarctic sea ice cover has increased under the effects of climate change

 

The first direct evidence that marked changes to Antarctic sea ice drift have occurred over the last 20 years, in response to changing winds, is published this week in the journal Nature Geoscience. Scientists from NERC's British Antarctic Survey (BAS) and NASA's Jet Propulsion Laboratory (JPL), Pasadena California explain why, unlike the dramatic losses reported in the Arctic, the Antarctic sea ice cover has increased under the effects of climate change.

 

Maps created by JPL using over 5 million individual daily ice motion measurements captured over a period of 19 years by four US Defense Meteorological satellites show, for the first time, the long-term changes in sea ice drift around Antarctica.

 

Lead author, Dr Paul Holland of BAS says: "Until now these changes in ice drift were only speculated upon, using computer models of Antarctic winds. This study of direct satellite observations shows the complexity of climate change. The total Antarctic sea-ice cover is increasing slowly, but individual regions are actually experiencing much larger gains and losses that are almost offsetting each other overall. We now know that these regional changes are caused by changes in the winds, which in turn affect the ice cover through changes in both ice drift and air temperature. The changes in ice drift also suggest large changes in the ocean surrounding Antarctica, which is very sensitive to the cold and salty water produced by sea-ice growth."

 

"Sea ice is constantly on the move; around Antarctica the ice is blown away from the continent by strong northward winds. Since 1992 this ice drift has changed. In some areas the export of ice away from Antarctica has doubled, while in others it has decreased significantly."

Sea ice plays a key role in the global environment – reflecting heat from the sun and providing a habitat for marine life. At both poles sea ice cover is at its minimum during late summer. However, during the winter freeze in Antarctica this ice cover expands to an area roughly twice the size of Europe. Ranging in thickness from less than a metre to several metres, the ice insulates the warm ocean from the frigid atmosphere above.

 

The new research also helps explain why observed changes in the amount of sea-ice cover are so different in the two Polar Regions. The Arctic has experienced dramatic ice losses in recent decades while the overall ice extent in the Antarctic has increased slightly. However, this small Antarctic increase is actually the result of much larger regional increases and decreases, which are now shown to be caused by wind-driven changes. In places, increased northward winds have caused the sea-ice cover to expand outwards from Antarctica. The Arctic Ocean is surrounded by land, so changed winds cannot cause Arctic ice to expand in the same way.

 

Dr Ron Kwok, JPL says, "The Antarctic sea ice cover interacts with the global climate system very differently than that of the Arctic, and these results highlight the sensitivity of the Antarctic ice coverage to changes in the strength of the winds around the continent."

There has been contrasting climate change observed across the Antarctic in recent decades. The Antarctic Peninsula has warmed as much as anywhere in the Southern Hemisphere, while East Antarctica has shown little change or even a small cooling around the coast. The new research improves understanding of present and future climate change. It is important to distinguish between the Antarctic Ice Sheet – glacial ice – which is losing volume, and Antarctic sea ice – frozen seawater – which is expanding.

 

 

http://www.eurekalert.org/pub_releases/2012-11/bas-was110912.php

Edited April 27, 2013 by knocker

[Methuselah]

I wish I knew who these so-called 'warmists' actually are? Other than (presumably) those who can interpret data...

[Gray-Wolf]

Again I'd remind folk that every past warming has seen the West Antarctic ice sheet suffer more melt than Greenland and I, personally, can find no good reason why we should depart from this natural process of global melt?

 

We know that we have locked the Antarctic away from general warming for the past 30 odd years due to our putting another 'trace gas' into the atmosphere but that damage is now on the mend and the ozone hole is shrinking so the 'lost years' of warming can now start to find there way back into the continent and the rapid melt of West Antarctica can continue.

 

Should we see another year of record losses from Greenland then I would suggest we expect major melt from West Antarctica as, to act Naturally' it will have a lot of ice to lose over a very short period of time?

 

The other thing is that we get to a point (like we are seeing across Greenland) when the surface layer of ice/snow is so dirty with the dust from the melted out snow that we see albedo collapse and rapid acceleration in mass loss. Further on the margins melt out and bare earth is increasingly exposed leading to the real 'albedo Flip' and the spectre of Rapid warming it brings with it?

[knocker]

Temperature change on the Antarctic Peninsula linked to the tropical Pacific

Abstract

Significant summer warming over the eastern Antarctic Peninsula in the last 50 years has been attributed to a strengthening of the circumpolar westerlies, widely believed to be anthropogenic in origin. On the western side of the Peninsula, significant warming has occurred mainly in austral winter and has been attributed to the reduction of sea ice. We show that austral fall is the only season in which spatially extensive warming has occurred on the Antarctic Peninsula. This is accompanied by a significant reduction of sea ice cover off the west coast. In winter and spring, warming is mainly observed on the west side of the Peninsula. The most important large-scale forcing of the significant wide-spread warming trend in fall is the extratropical Rossby wave train associated with tropical Pacific sea surface temperature anomalies. Winter and spring warming on the western Peninsula reflects the persistence of sea ice anomalies arising from the tropically forced atmospheric circulation changes in austral fall.

 

 

http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00729.1

[knocker]

Tropical air circulation drives fall warming on Antarctic Peninsula

The eastern side of the Antarctic Peninsula, a finger of the southern polar continent that juts toward South America, has experienced summer warming of perhaps a half-degree per decade – a greater rate than possibly anywhere else on Earth – in the last 50 years, and that warming is largely attributed to human causes.

 

But new University of Washington research shows that the Southern Hemisphere’s fall months – March, April and May – are the only time when there has been extensive warming over the entire peninsula, and that is largely governed by atmospheric circulation patterns originating in the tropics.

 

 

http://www.washington.edu/news/2013/05/15/tropical-air-circulation-drives-fall-warming-on-antarctic-peninsula/

Edited May 15, 2013 by knocker

[keithlucky]

Antarctic ice record broken again by 66000 sq km

Year No of Records 2010 129 2008 126 2006 29 2012 24 2007 21 2013 9 2009 8 2000 5 2004 5 1998 4 2005 3 1979 2 1980 1 it"s now in 6th place for daily records set.

Edited May 22, 2013 by keithlucky

[Methuselah]

Any data on volume or mass, Keith?

[keithlucky]

Any data on volume or mass, Keith?

No i"m afraid not just area extent of sea ice .

[Methuselah]

No i"m afraid not just area extent of sea ice .

Okay, Keith. Thanks anyhow!

[knocker]

I don't think it has been accurately measured Pete.

"We have a good handle of the extent of the Antarctic sea ice, but the thickness has been the missing piece to monitor the sea ice mass balance," said Thorsten Markus, one of the authors of the study and Project Scientist for ICESat-2, a satellite mission designed to replace the now defunct ICESat. ICESat-2 is scheduled to launch in 2016. "The extent can be greater, but if the sea ice gets thinner, the volume could stay the same."

 

 

 There have been number of papers explaining this but forgetting fresh water runoff for the moment these are two.

 

Opposite behaviors? Arctic sea ice shrinks, Antarctic grows

 

http://www.eurekalert.org/pub_releases/2012-10/nsfc-oba102312.php

 

Why Antarctic sea ice cover has increased under the effects of climate change

 

http://www.eurekalert.org/pub_releases/2012-11/bas-was110912.php

Edited May 22, 2013 by knocker

[keithlucky]

I don't think it has been accurately measured Pete.

 

 There have been number of papers explaining this but forgetting fresh water runoff for the moment hese are two.

 

Opposite behaviors? Arctic sea ice shrinks, Antarctic grows

 

http://www.eurekalert.org/pub_releases/2012-10/nsfc-oba102312.php

 

Why Antarctic sea ice cover has increased under the effects of climate change

 

http://www.eurekalert.org/pub_releases/2012-11/bas-was110912.php

Absolutely brilliant how GW causes warming causing cooling ,talk about having your your cake and eating it !

[knocker]

Absolutely brilliant how GW causes warming causing cooling ,talk about having your your cake and eating it !

 

I know, it's deuced clever.