Antarctic Ice Discussion

[knocker]

Back to basics.

 

The key to understanding simultaneous warming in the Antarctic region and increases sea ice extent is well explained in Zhang 2007:

 

The model shows that an increase in surface air temperature and downward longwave radiation results in an increase in the upper-ocean temperature and a decrease in sea ice growth, leading to a decrease in salt rejection from ice, in the upper-ocean salinity, and in the upper-ocean density. The reduced salt rejection and upper-ocean density and the enhanced thermohaline stratification tend to suppress convective overturning, leading to a decrease in the upward ocean heat transport and the ocean heat flux available to melt sea ice. The ice melting from ocean heat flux decreases faster than the ice growth does in the weakly stratified Southern Ocean, leading to an increase in the net ice production and hence an increase in ice mass. This mechanism is the main reason why the Antarctic sea ice has increased in spite of warming conditions both above and below during the period 1979–2004 and the extended period 1948–2004.

 

Generally, in SH winter, ice extent can grow more than usual, while in summer the overall satellite observations show that ice mass of Antarctica is decreasing.

 

With more snow precipitation in Antarctica one might expect that the ice mass would grow as well, but at this time the ice discharge (calving) rates are increasing.

 

Data confirms these three factors:

• Antarctica is warming
• Antarctic sea ice extent is increasing
• Antarctic land Ice mass is decreasing

A warmer world seems to translate to more snow but faster loss of that snow in the spring/summer months.

 

http://ossfoundation.us/projects/environment/global-warming/antarctic-ice-melt

Edited December 15, 2013 by knocker

[mikeworst]

Mmmm someone is telling porkies?  http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120013495_2012013235.pdf

[Gray-Wolf]

I think the work is just showing it's age and our increase in data from the continent Mike. 6 years ago we still thought the Arctic was safe until 2100 didn't we? As it is the research published from ESA over the past couple of days shows a continued increase in the mass loss from W.A,I,S, and the AGU saw us introduced to the concerns that P.I.G. could escape the bottleneck over the coming years massively increasing the losses again as the 'ice front' retreats into a wider melt basin. couple that with the News that Ted Scambos brought us about the imminent loss of the rest of Larsen B and you can see what 6 years does in climate science of the Antarctic continent these days? I guess a lot of the work folk engaged in through the noughties ( when we suddenly realised that things were a lot worse than we previously thought, remember the B.A.S. and their 'Waking the Sleeping giant' report from 2002?) is now showing results and they do nothing to allay our fears.

[4wd]

Mmmm someone is telling porkies?  http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120013495_2012013235.pdf

We need that pasting in I think:

SCAR ISMASS Workshop, July 14, 2012

 

Mass Gains of the Antarctic Ice Sheet Exceed Losses

H. Jay Zwally'. Jun Li', John Robbins2, Jack 1. Saba2, Donghui Yi', Anita Brenner', and David Bromwich4

Abstract

During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded

the mass loss from ice discharge by 49 Gtlyr (2.5% of input), as derived from ICESat laser

measurements of elevation change. The net gain (86 Gtlyr) over the West Antarctic (WA) and

East Antarctic ice sheets (W A and EA) is essentially unchanged from revised results for 1992 to

2001 from ERS radar altimetry. Imbalances in individual drainage systems (DS) are large

(-68% to +103% of input), as are temporal changes (-39% to +44%). The recent 90 Gtlyr loss

from three DS (Pine Island, Thwaites-Smith, and Marie-Bryd Coast) of WA exceeds the earlier

61 Gtlyr loss, consistent with reports of accelerating ice flow and dynamic thinning.  Similarly,

the recent 24 Gtlyr loss from three DS in the Antarctic Peninsula (AP) is consistent with glacier

accelerations following breakup of the Larsen B and other ice shelves. In contrast, net increases

in the five other DS ofWA and AP and three of the 16 DS in East Antarctica (EA) exceed the

increased losses.  Alternate interpretations of the mass changes driven by accumulation variations

are given using results from atmospheric-model re-analysis and a parameterization based on 5%

change in accumulation per degree of observed surface temperature change. A slow increase in

snowfall with climate wanning, consistent with model predictions, may be offsetting increased

dynamic losses.

[jonboy]

I think the work is just showing it's age and our increase in data from the continent Mike. 6 years ago we still thought the Arctic was safe until 2100 didn't we? As it is the research published from ESA over the past couple of days shows a continued increase in the mass loss from W.A,I,S, and the AGU saw us introduced to the concerns that P.I.G. could escape the bottleneck over the coming years massively increasing the losses again as the 'ice front' retreats into a wider melt basin. couple that with the News that Ted Scambos brought us about the imminent loss of the rest of Larsen B and you can see what 6 years does in climate science of the Antarctic continent these days? I guess a lot of the work folk engaged in through the noughties ( when we suddenly realised that things were a lot worse than we previously thought, remember the B.A.S. and their 'Waking the Sleeping giant' report from 2002?) is now showing results and they do nothing to allay our fears.

 

Hang on Knocker presents a paper dated 2007 to justify your points yet you dismiss a 2012 paper that counters that presented by Mike so how does a 2012 paper show its age I would suggest its the 2007 paper showing its age so your argument seems a little lame 

[knocker]

Apologies this is a bit out of date being four days old.

 

East Antarctica is sliding sideways: Ice loss on West Antarctica affecting mantle flow below

 

Now that West Antarctica is losing weight—that is, billions of tons of ice per year—its softer mantle rock is being nudged westward by the harder mantle beneath East Antarctica.

The discovery comes from researchers led by The Ohio State University, who have recorded GPS measurements that show West Antarctic bedrock is being pushed sideways at rates up to about twelve millimeters—about half an inch—per year. This movement is important for understanding current ice loss on the continent, and predicting future ice loss.

Read more at: http://phys.org/news/2013-12-east-antarctica-sideways-ice-loss.html#jCp

 

 

The continent of Antarctica has been losing more than 100 cubic kilometers (24 cubic miles) of ice per year since 2002.

 

Source: http://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html

Edited December 15, 2013 by knocker

[Gray-Wolf]

The study period NASA quotes is 2003 to 2008 whereas the ESA data is the past 3 years jon, simplulls!

[BornFromTheVoid]

Just a question. If that Zwally et al presentation suggesting a net gain in Antarctic ice mass from 2003-08 is worthy of posting again and again here, what's wrong with the numerous studies suggesting the opposite?

What is different with the Zwally et al study that it wasn't influenced by (the AGW sceptic claims of) the drive for grant money, faulty peer review system, left wing anti-capitalist agenda, or whatever other excuses are used for dismissing most peer reviewed or conference data? Why is this study impervious to all that?

Edited December 15, 2013 by BornFromTheVoid

[UV-RAY]

Just a question. If that Zwally et al presentation suggesting a net gain in Antarctic ice mass from 2003-08 is worthy of posting again and again here, what's wrong with the numerous studies suggesting the opposite?

What is different with the Zwally et al study that it wasn't influenced by (the AGW sceptic claims of) the drive for grant money, faulty peer review system, left wing anti-capitalist agenda, or whatever other excuses are used for dismissing most peer reviewed or conference data? Why is this study impervious to all that?

Which study is that BFTV?

[BornFromTheVoid]

Which study is that BFTV?

 

The Zwally one (conference abstract) has been posted by Mikeworst, 4wd and was posted again by someone else in the last month, can't quite remember who.

 

The studies suggesting Antarctica is losing mass are numerous, would you like me to post some?

[UV-RAY]

The Zwally one (conference abstract) has been posted by Mikeworst, 4wd and was posted again by someone else in the last month, can't quite remember who.

 

The studies suggesting Antarctica is losing mass are numerous, would you like me to post some?

I haven't read any of it  so I can't comment so yes please.

[Methuselah]

 

The studies suggesting Antarctica is losing mass are numerous, would you like me to post some?

Which would be very useful. Because mass is the thing that really matters...

[knocker]

 

October 23, 2012Antarctica is shedding an average of 190 billion tonnes of ice everyday, according to a landmark study that used satellites to ''weigh''the vast landmass.Although parts of East Antarctica are growing, glaciers in WestAntarctica are melting faster, leading to a net loss of ice across thecontinent, according to the study published in the journal Nature.''We're confident that the ice cover is shrinking, and the rate alongthe Amundsen Sea coast is accelerating,'' said the lead researcherProfessor Matt King, of the University of Tasmania.Rapid melting in some parts of the continent is partially offset byheavy snowfalls elsewhere, meaning that the net loss of ice per yearis about 69 billion tonnes.Previous studies had struggled toaccurately map the land mass under most of Antarctica's huge iceshelves, and this knowledge is crucial to measuring the thickness ofthe ice.

 

https://groups.google.com/forum/#!topic/alt.global-warming/FBvoL8bg3fk

 

http://phys.org/news/2012-10-antarctic-weight-loss.html

Edited December 15, 2013 by knocker

[keithlucky]

https://groups.google.com/forum/#!topic/alt.global-warming/FBvoL8bg3fk

LOL defies all logic.Record ice growth and you still look for melt sad .For example the Emperor Penguin had to march a extra 25 k to reach the same breeding grounds .

Edited December 15, 2013 by keithlucky

[BornFromTheVoid]

Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE 2006

 

Measurements of Time-Variable Gravity Show Mass Loss in Antarctica 2006

 

Ice-sheet mass balance: assessment, attribution and prognosis 2007

 

Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets 2007

 

Role of Antarctic ice mass balance in present-day sea-level change 2008

 

Decadal Mass Balance of the Greenland and Antarctic Ice Sheets from High Resolution Elevation Change Analysis of ERS-2 and Envisat Radar Altimetry Measurements 2008

 

Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE 2009

 

Ice sheet mass balance and sea level 2009

 

 

I had intended to continue this on to 2013, but I'm running out of time! I might update the list later this evening.

A simple google scholar search of Antarctic Mass Balance yields a huge array of papers and conference abstracts though.

[knocker]

LOL defies all logic.Record ice growth and you still look for melt sad .For example the Emperor Penguin had to march a extra 25 k to reach the same breeding grounds .

 

What is sad is that you don't seem able to differentiate between sea ice and land ice sheets.

Edited December 15, 2013 by No-Time Toulouse

[BornFromTheVoid]

LOL defies all logic.Record ice growth and you still look for melt sad .For example the Emperor Penguin had to march a extra 25 k to reach the same breeding grounds .

 

Keith, you're referring to sea ice, which forms on the Southern Ocean, which is experiencing record levels, nobody is denying that.

What knocker linked to was data on the ice sheet, which is sitting on the Antarctic continental land mass. Most studies suggest that the ice sheet is losing mass. This doesn't contradict that record levels of sea ice are currently being observed.

 

What Knocker posted was neither illogical or sad, so I suggest you edit your post.

[UV-RAY]

Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE 2006

 

Measurements of Time-Variable Gravity Show Mass Loss in Antarctica 2006

 

Ice-sheet mass balance: assessment, attribution and prognosis 2007

 

Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets 2007

 

Role of Antarctic ice mass balance in present-day sea-level change 2008

 

Decadal Mass Balance of the Greenland and Antarctic Ice Sheets from High Resolution Elevation Change Analysis of ERS-2 and Envisat Radar Altimetry Measurements 2008

 

Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE 2009

 

Ice sheet mass balance and sea level 2009

 

 

I had intended to continue this on to 2013, but I'm running out of time! I might update the list later this evening.

A simple google scholar search of Antarctic Mass Balance yields a huge array of papers and conference abstracts though.

Thanks BFTV, I'll have to catch up on all of this tomorrow as there is far too much to take in for this old man.

[stewfox]

What is sad is that you don't seem able to differentiate between sea ice and land ice sheets.

 

Global sea ice remains above the long term average.

 

So GPS measurements that show West Antarctic bedrock is being pushed sideways at rates up to about twelve millimeters—about half an inch—per year. This movement is important for understanding current ice loss on the continent, and predicting future ice loss. 

One footbal field = 100 metres or 10,000 millmetres

 

So in just under a thousand years the whole of the western antartic bed rock will move about 1 football field or 0.0000001% of its length. Natural varibility would be 100 times greater then this.Such headlines belong in the Daily Express. 

Edited December 15, 2013 by stewfox

[Gray-Wolf]

Stew. were talking about the plastic deformation of rock here? does the fact that the change in mass balance is having such an impact on solid rock escape you or is it me that is missing something. What do you know of that could squash similar rock to see such deformation so we can quantify the forces at work here?

 

The sad reality is that the isostatic rebound is so slow, compared to the mass loss, that W.A.I.S and Greenland bedrock ,pushed below sea level by the weight of ice above, will not rebound in time to stop the inundation of those basins ( and float off of the remaining ice) before the rock 'rebounds' enough to rise above sea level. This means the rapid degradation of the ice sheet rather than a slow ,drip,drip melt. to me such things are significant ( even if in my great grandchildrens life experience and not mine but then I do care about such....).

Edited December 15, 2013 by Gray-Wolf

[Methuselah]

Global sea ice remains above the long term average.

 

So GPS measurements that show West Antarctic bedrock is being pushed sideways at rates up to about twelve millimeters—about half an inch—per year. This movement is important for understanding current ice loss on the continent, and predicting future ice loss. 

One footbal field = 100 metres or 10,000 millmetres

 

So in just under a thousand years the whole of the western antartic bed rock will move about 1 football field or 0.0000001% of its length. Natural varibility would be 100 times greater then this.Such headlines belong in the Daily Express. 

But it's the mass of melting ice that raises sea-levels, not its spatial extent...

[Gray-Wolf]

And the sad part of this is the outflow ( increasing ) of freshwater melt may well be helping extend the sea ice in the Weddell area? We already know that the ozone hole has brought it's own impacts with it and that we have seen both the circumpolar winds and current increase over the same period that we have seen this slow extension in sea ice cover ( and let us remember that we see declining sea ice area around the Continent as well and this in areas that should raise concerns?).

 

Anyhow the 'majik shield' the circumpolars have helped maintain will not remain for ever and the general warming will push into the continent. In the same way we ought expect 'cool natural drivers' to move back toward warm drivers we should 'expect' this force for isolation to show us it's other face.

 

EDIT: Hey BFTV what are the odds, if we hit the lead Climate misleader outlets for info, that the Zwally paper will show up over the past 4 weeks? I kinda think that the only way they 'link' to stuff is if the 'link' appears there for them ( " go on my minions! spread the word...fly my pretty's !  Fly!!!) as when we normally ask them for links to their statements we are met with blanks?

Edited December 15, 2013 by Gray-Wolf

[mikeworst]

Facts are simple, the antarctic is not warming and therefore the ice cannot be melting. Simples.

[Methuselah]

Facts are simple, the antarctic is not warming and therefore the ice cannot be melting. Simples.

Some parts are, some parts are not...

[BornFromTheVoid]

Facts are simple, the antarctic is not warming and therefore the ice cannot be melting. Simples.

 

Can you back up those facts with evidence Mike?

Also, are air temperatures the only thing that matters?