Antarctic Ice Discussion

[Gray-Wolf]

The Southern ocean is one of our largest carbon sinks . Any slowing in subduction will reduce the effectiveness of this sink and allow more CO2 to remain in in the atmosphere and hasten the collapse in the subduction.

 

And what of the rest of the ocean warming? without 'normal services' will the tropical oceans just turn into one great Nino-esque heat generator?

[knocker]

Purvis Glacier Retreat, South Georgia Island

 

Purvis Glacier is on the norteastern coast of the island, terminating on land near Possession Bay. The British Antarctic Survey (BAS) has mapped many aspects of the island including glacier front changes. Their mapping indicated below shows that the Purvis Glacier terminus was on the coastline in 1974. Here we examine Landsat imagery from 1999 to 2014 to identify more recent changes. Cook et al (2010) quantified the change in these maps noting that 97% of the 102 coastal glacier retreated between the 1950′s and today.

 

http://glacierchange.wordpress.com/2014/03/09/purvis-glacier-retreat-south-georgia-island/?utm_source=dlvr.it&utm_medium=twitter

[knocker]

The Tasmania-based Antarctic Climate and Ecosystems Cooperative Research Centre has just released a new "position analysis" of the brain-achingly complex issue of southern hemisphere sea ice.

 

It's got a lot of science in it.

[stewfox]

Satellites Confirm Antarctic Is Getting Colder

 

http://notalotofpeopleknowthat.wordpress.com/2013/09/09/satellites-confirm-antarctic-is-getting-

 

Extent greatest its ever been for time of year

 

http://sunshinehours.files.wordpress.com/2014/04/antarctic_sea_ice_extent_2014_day_92_1981-2010.png

Edited April 6, 2014 by stewfox

[knocker]

Wrong thread.

Edited April 7, 2014 by knocker

[keithlucky]

Antarctic ice regrowth smashes all previous records 220,000sq km above previous day 34 record

Edited April 12, 2014 by keithlucky

[Tasboy]

The current sea ice AREA is even more impressive. Predominantly stemming from the Weddell Sea where there have been anomalously cold SSTs.

[BornFromTheVoid]

The current sea ice AREA is even more impressive. Predominantly stemming from the Weddell Sea where there have been anomalously cold SSTs.

Yup, sea ice around Antarctica looking pretty impressive, maintaining the record/near record high levels of recent months. I'd say there's an awful lot of head scratching going on at the moment!

[Tasboy]

Just a message about NSIDC updating their data...

 

NSIDC have updated their January-September 2013 Southern Hemisphere sea ice concentrations (from "near-real-time" to "final") and some of the 2013 records have changed marginally. New sea ice extent maximum was achieved on 30 Sep 2013 (previously 1 Oct 2013 with near-real-time data), and has increased ever so slightly from the near-real-time value.

Compare:

- http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent.html

with

- http://www.cawcr.gov.au/staff/preid/seaice/sea_ice_table_extent_old.html

 

Edit...

Ok, I've just noticed that the old sea ice table has been overwritten by the new one. A quirk of our web setup I'm afraid. Sorry.

Edited April 14, 2014 by Tasboy

[stewfox]

Yup, sea ice around Antarctica looking pretty impressive, maintaining the record/near record high levels of recent months. I'd say there's an awful lot of head scratching going on at the moment!

 

Whats your theory ? , is it enough to say its just a different set up ? More records being broken down there

 

https://sunshinehours.files.wordpress.com/2014/04/antarctic_sea_ice_extent_2014_day_105_1981-2010.png

Edited April 18, 2014 by stewfox

[BornFromTheVoid]

Whats your theory ? , is it enough to say its just a different set up ? More records being broken down there

 

https://sunshinehours.files.wordpress.com/2014/04/antarctic_sea_ice_extent_2014_day_105_1981-2010.png

 

Hard to say, but with all things climate related, there's probably a number of factors causing it. Personally, just on gut feeling, I think the freshening and cooling of the surface water from glacial melt is a big factor, more so than the winds.

Either way I think more research and hopefully a reasonable explanation is needed.

[Gray-Wolf]

Sadly no matter what the causes of the Sea ice growth warmth will win out in the end. If , as BFTV thinks, it is a combination of factors ( freshening with cold glacial melt water from ice sheet melt, circumpolar wind/current abnormalities driven by ozone issues, long cycle natural forcings etc) then we can see that some of them will not always be present? The ozone hole is set to mend, long cycle naturals will reverse and warmer oceans will deal faster with Ice sheet run off.

 

As it is a recent paper looked at La Ninas impacts on P.I.G. losses and so any Nino may see an increase in losses from there liberating a lot of ice into one of the 'sea ice growth' areas.

 

Maybe we need to be looking at the make up of the ice that remains at summers end to see if it is 'sea ice' or glacial debris ( as we saw with the 'stuck Ship' earlier this year?) as maybe Sea ice is being impacted by ever increasing land ice collapsing into the Southern Ocean?

[knocker]

But will it reverse?

 

Study projects big thaw for Antarctic sea ice

http://www.vims.edu/newsandevents/topstories/ross_sea_thaw.php

[BARRY]

but there is over 3 million sq km more ice now than there was in 1980

[stewfox]

Hard to say, but with all things climate related, there's probably a number of factors causing it. Personally, just on gut feeling, I think the freshening and cooling of the surface water from glacial melt is a big factor, more so than the winds.

Either way I think more research and hopefully a reasonable explanation is needed.

 

Can one not check for a reduction in surface salinity ?

[knocker]

Can one not check for a reduction in surface salinity ?

 

Measurements of temperature and salinity with useful accuracy have only been available for the past 60 years or so, and there are few place where high quality measurement have been made over several decades, This severely limits the ability to directly measure climate-scale change in the ocean.

[keithlucky]

Another daily record for Antarctic sea ice http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.antarctic.png http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

But will it reverse?

 

Study projects big thaw for Antarctic sea ice

http://www.vims.edu/newsandevents/topstories/ross_sea_thaw.php

LOL

Edited April 24, 2014 by keithlucky

[Gray-Wolf]

Just how removed from reality are you KL? Is there a warming trend on our planet ( ocean and atmosphere) ? 

 

If we see 'warming' then what is the end result for all the ice on our planet? 

 

Your delight in seeing these small increases reminds me of the delight of the Deniers at the reversal of natural warm drivers over the past 15yrs when we all know full well that we will see a resumption in the warming rates ( and more!) that we saw from the 70's to the late 90's. Worse than that only a full suite of negative drivers appears capable now of impacting the rises in temperature across the lower latitudes ( the poles appear to be in runaway warming regardless of the cool drivers???) and any combination not giving full negative forcing allows blips in global temps ( like 2010's record warm year due to a very short Nino).

 

The worst impact of the ozone hole are past and the climate forcing we see over antarctica has been in sway for over 30yrs. how long before nature gives us the reverse of this? ( this year?)

[knocker]

Yes GW and I was thinking in many ways the sudden reduction in stratospheric ozone and the advent of the satellite era was a little unfortunate.

 

Just been reading a paper:

 

Stratospheric Polar Vortices

 

Darryn W. Waugh

 

Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland, USA

 

Lorenzo M. Polvani

 

Department of Applied Physics and Applied Mathematics and Department of Earth and Environmental SciencesColumbia University, New York, New York, USA

 

 

Finally, and perhaps most importantly, the recovery of Antarctic ozone is predicted to cause a positive trend in lower stratospheric temperatures and vortex strength in late spring to summer. As discussed in section 5, changes in the Antarctic lower stratospheric temperatures over the last 2 decades have been linked to changes in Southern Hemisphere climate. The ozone recovery over the next 4 to 5 decades is predicted to reverse these changes [e.g., Son et al., 2008; Perlwitz et al., 2008]. It is important to note that in the latter part of the 20th century, the impact of ozone depletion on the tropospheric circulation has been in the same sense as the impact of increasing GHGs. However, as ozone recovers, the stratospheric impact will oppose, and even reverse, some of the expected changes to increases in GHGs.

[knocker]

This has to be a worry. Is this "collapse"?

 

Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013

 

We combine measurements of ice velocity from Landsat feature tracking and satellite radar interferometry, and ice thickness from existing compilations to document 41 years of mass flux from the Amundsen Sea Embayment (ASE) of West Antarctica. The total ice discharge has increased by 77% since 1973. Half of the increase occurred between 2003 and 2009. Grounding-line ice speeds of Pine Island Glacier stabilized between 2009 and 2013, following a decade of rapid acceleration, but that acceleration reached far inland and occurred at a rate faster than predicted by advective processes. Flow speeds across Thwaites Glacier increased rapidly after 2006, following a decade of near-stability, leading to a 33% increase in flux between 2006 and 2013. Haynes, Smith, Pope, and Kohler Glaciers all accelerated during the entire study period. The sustained increase in ice discharge is a possible indicator of the development of a marine ice sheet instability in this part of Antarctica.

 

http://onlinelibrary.wiley.com/doi/10.1002/2013GL059069/abstract

Edited April 24, 2014 by knocker

[stewfox]

Just how removed from reality are you KL? Is there a warming trend on our planet ( ocean and atmosphere) ? 

 

If we see 'warming' then what is the end result for all the ice on our planet? 

 

Your delight in seeing these small increases reminds me of the delight of the Deniers at the reversal of natural warm drivers over the past 15yrs when we all know full well that we will see a resumption in the warming rates ( and more!) that we saw from the 70's to the late 90's. Worse than that only a full suite of negative drivers appears capable now of impacting the rises in temperature across the lower latitudes ( the poles appear to be in runaway warming regardless of the cool drivers???) and any combination not giving full negative forcing allows blips in global temps ( like 2010's record warm year due to a very short Nino).

 

The worst impact of the ozone hole are past and the climate forcing we see over antarctica has been in sway for over 30yrs. how long before nature gives us the reverse of this? ( this year?)

 

At the end of the day we can only got on the facts not changing theories

 

We have had no significant warming since 1997 and a cooling Antarctica (some parts) with increasing sea ice levels

 

Maybe in 2100 things will be very different but I think most folk want evidence

[Polar Maritime]

At the end of the day we can only got on the facts not changing theories

 

We have had no significant warming since 1997 

 

And theories change to get the facts, that's Science is it not?

[knocker]

At the end of the day we can only got on the facts not changing theories

 

 

I take it then you are disputing this fact? Your reasons for so doing are of interest.

 

 

We combine measurements of ice velocity from Landsat feature tracking and satellite radar interferometry, and ice thickness from existing compilations to document 41 years of mass flux from the Amundsen Sea Embayment (ASE) of West Antarctica. The total ice discharge has increased by 77% since 1973. Half of the increase occurred between 2003 and 2009. Grounding-line ice speeds of Pine Island Glacier stabilized between 2009 and 2013, following a decade of rapid acceleration, but that acceleration reached far inland and occurred at a rate faster than predicted by advective processes. Flow speeds across Thwaites Glacier increased rapidly after 2006, following a decade of near-stability, leading to a 33% increase in flux between 2006 and 2013. Haynes, Smith, Pope, and Kohler Glaciers all accelerated during the entire study period. The sustained increase in ice discharge is a possible indicator of the development of a marine ice sheet instability in this part of Antarctica.

 

And this

 

Previous rapid thinning of Pine Island Glacier sheds light on future Antarctic ice loss

 

New research, published this week in Science, suggests that the largest single contributor to global sea level rise, a glacier of the West Antarctic Ice Sheet, may continue thinning for decades to come. Geologists from the UK, USA and Germany found that Pine Island Glacier (PIG), which is rapidly accelerating, thinning and retreating, has thinned rapidly before. The team say their findings demonstrate the potential for current ice loss to continue for several decades yet.

 

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=2514

Edited April 24, 2014 by knocker

[stewfox]

One of your more offensive contributions GW totally unnecessary and adding absolutley nothing to the debate and only goes to debase your point

 

 

NO worries I think its in the year 3535 we tend to agree ?? year 9595 one to watch see if the Antarctic is still growing

 

Edited April 25, 2014 by stewfox

[Tasboy]

but there is over 3 million sq km more ice now than there was in 1980

Um, how do you come to this value?

For Antarctica:

2014 annual day maximum = 19.58 million square kms (30 September)

1980 annual day maximum = 19.09 million square kms (23 September)