Antarctic Ice Discussion

[Gray-Wolf]

What are we looking at here exactly?

i see a graph with a timeline but am not seeing what the vertical axis is for?

Edited August 5, 2012 by Gray-Wolf

[stewfox]

Vague memories of there being a seesaw action with Arctic/Antarctic ice - historically as one declined, the other expanded. Anyone know if this is still holding true today?

Its about 1m above the long term average at present

http://arctic.atmos....y.antarctic.png

Re Seesaw I dont know if records go back that far to support that.

Seems to be little quickly avaiible research on Antartica but i guess its not head line news.

e.g how much additional ice has melted globally cf summer 79 to summer 2012 . 2 or 3% ?? maybe 0% ??

Edited August 8, 2012 by stewfox

[Methuselah]

If increased precipitation can lead to increasing ice-thicknesses on Antarctica, then that can only be a good thing for mankind - so long as we don't fritter away the extra-time we might have on fossil fuel-based squabbling!

[Waterspout]

There's some new research just published in Nature "Antarctic Peninsula warming relative to Holocene climate and ice shelf history" - which reconstructs temperatures for the past 15,000 years.

I havn't been able to see the paper, or indeed a graph, but I'm a little confused.

The BAS report on it as follows: http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=1892

Their summary being: "The first comprehensive reconstruction of a 15,000 year climate history from an ice core collected from James Ross Island in the Antarctic Peninsula region is reported this week in the journal Nature. The scientists reveal that the rapid warming of this region over the last 100 years has been unprecedented and came on top of a slower natural climate warming that began around 600 years ago."

Note the use of "rapid warming of this region over the last 100 years has been unprecedented"

So, I tried to search for more information, again couldn't actually find the paper itself or a graph! But The Australian reports as follows: http://www.theaustralian.com.au/news/health-science/ice-core-warming-within-bounds/story-e6frg8y6-1226456144974

"RECENT warming of the Antarctic peninsula is unusual but not unprecedented relative to natural variation, according to research published today in Nature.

The Antarctic is currently one of the most rapidly warming regions on Earth but an analysis of ice-core records has found the rise in temperatures is "within the bounds of natural climate variability over the past 600 years"."

LOL! This paper is only just trickling through the media, so may be a clearer picture will emerge!

[BornFromTheVoid]

There's some new research just published in Nature "Antarctic Peninsula warming relative to Holocene climate and ice shelf history" - which reconstructs temperatures for the past 15,000 years...

...LOL! This paper is only just trickling through the media, so may be a clearer picture will emerge!

From the paper's abstract.

Although warming of the northeastern Antarctic Peninsula began around 600 years ago, the high rate of warming over the past century is unusual (but not unprecedented) in the context of natural climate variability over the past two millennia

That was easy enough to clear up!

http://www.nature.co...ature11391.html

[4wd]

They all seem to be stating their pre-conceived positions on what they think ought to be happening.

I was under the impression that Antarctica isn't warming and Antarctic sea ice has been consistently above long term averages for some time.

There was a program on the other night with the long haired Scottish bloke informing us that penguins were under threat because Antarctic sea-ice had retreated so much, I thought "?"

[Waterspout]

From the paper's abstract.

That was easy enough to clear up!

http://www.nature.co...ature11391.html

Oh yes! I must email the BAS, as their press release is rather misleading and not the same as to what the Paper abstract clearly says.

Edited August 23, 2012 by Waterspout

[Waterspout]

Oh yes! I must email the BAS, as their press release is rather misleading and not the same as to what the Paper abstract clearly says.

They've now changed it:

"This is very well spotted and is an error on our part. The press release has now been amended to ‘very unusual’ rather than ‘unprecedented’. Many thanks for bringing my attention to this.

Kind regards,"

[Gray-Wolf]

I was under the impression that Antarctica isn't warming and Antarctic sea ice has been consistently above long term averages for some time.

I think the data clearly shows we are losing 'ice mass' across continental Antarctic and that 'increased precipitation', in the form of snow, is 'seeding' the edges of the pack and allowing expansion there? As we saw last year with the 'million drop' storm this is peripheral ice and not up to the rough seas conditions that the winter southern ocean throws at it.

You appear well placed to answer this question Four. What is the fascination that the 'Faux Sceptic' has with the seasonal sea ice around Antarctica? I only know what the Arctic sea ice 'extent' is like and that any 'extension' (like this springs 'average extent') to it is fleeting and does not appear to have any influence on the Polar melt over the following summer season?

Can it really be seen as some kind of 'counterbalence' to the terrible loss of sea ice volume we are seeing occurring across the Arctic or ,indeed, the mass loss inside Antarctica itself?

Edited August 23, 2012 by Gray-Wolf

[knocker]

Antarctic Climate Change and the Environment

Full report.

http://www.scar.org/publications/occasionals/acce.html

[knocker]

ENSO-related impacts on Antarctic sea ice: a synthesis of phenomenon and mechanisms

http://www.ldeo.columbia.edu/res/div/ocp/pub/yuan/enso.pdf

[Methuselah]

Why is anything that is consistent with the AGW theory labeled as 'pre-conceived'?

[Gray-Wolf]

I think it is only viewed so by folk who do not cope well with the notion that the general AGW premise may be now occuring? Sadly many of us thought we had a lot longer to debate the impacts but it would appear that they are now beginning to manifest a lot faster than we hoped (or did we all just focus on the most optimistic forecasts?).

Due to the 'speed up' in climate impacts I'm growing ever concerned that the ozone hole fortress we built around Antarctica will now be breached and we will see dramatic warming of the lower levels and impacts on sea levels.

Still ,all eyes are up north a.t.m.

[minus 9]

why is there never no talk of antartic sea ice. currently well above average. and has been steadily rising for the last few years.

[knocker]

why is there never no talk of antartic sea ice. currently well above average. and has been steadily rising for the last few years.

Is it and has it?

The Antarctic continent is surrounded by the sea ice zone where, by late winter, the ice covers an average area of 19 x 106 km2, which is more than the area of the continent itself. At this time of year the northern ice edge is close to 60° S around most of the continent, and near 55° S to the north of the Weddell Sea. Unlike the Arctic, most of the Antarctic sea ice melts during the summer so that by autumn it only covers an area of about 3 x 106km2. Most Antarctic sea ice is therefore first-year ice, with the largest area of multi-year ice being over the western Weddell Sea. Consequently most sea ice around the continent is relatively thin, with an average thickness of about 1-2 m.

Source:

John Turner and Gareth J. Marshall, " Climate Change in Polar Regions", Routledge.

Edited September 14, 2012 by knocker

[Gray-Wolf]

I think it's because it's the 'Antarctic' which is a continent with a 'seasonal' ice pack?

We often hear of some magical 'balancing act' between north and south but it is no such thing (just crunch the numbers if you don't believe me) but when things are bad in the Arctic there are plenty of folk who wish to say "oooh ,look ,squirrels!!!"

Either the ozone will heal and we'll see massive land losses or the Arctic meltdown will force global temps so high as to overcome the Ozone effects and we'll see massive land mass losses. Either way we will see massive mass losses from Antarctica over the next 15 years.

[Methuselah]

We might GW...

[Gray-Wolf]

Sorry Pete, my 'flavour of speach again! True we may see global temps fended off from the southern continent for the next 15yrs or global temps could fall back to what they were prior to the warming but I struggle to see this occuring.

We know that warm ,southern ocean waters are already beyond the pine glacier ciomplex (2 years ago) bound for Ross and we know that the upper trop is already warming and that this warmth is headed lower (nearly at the tops of the higher peaks 3 years ago?) . With the added energy the Arctic is now beginning to impart to the climate system then this 'extra push' may be the final straw that allows the warmth in? As we have seen with the Arctic Ice loss favours ice loss via the albedo flip it induces and the latest papers on the 'saddle melt' of ice sheets has me wondering whether this process will eventually impact the central Antarctic?

Edited September 14, 2012 by Gray-Wolf

[knocker]

As we have seen with the Arctic Ice loss favours ice loss via the albedo flip it induces and the latest papers on the 'saddle melt' of ice sheets has me wondering whether this process will eventually impact the central Antarctic?

I wonder about that GW. I think the ice shelves and mechanical processes may be more important.

The Antarctic Ice Sheet has a maximum thickness ofabout 4700 m and this huge mass of ice gradually flows down towards the edge of the continent, moving fastest in a number of ice streams that travel at speeds of up to 500 m per year. Once the ice streams reach the edge of the continent they either calve into icebergs, which move northwards, or start to float on the ocean as ice shelves. The ice shelves constitute II % of the total area of the Antarctic, with the two largest shelves being the Ronne-Filchner and the Ross Ice Shelves, which have areas of 0.53 x 106 km2 and 0.50 x 106 km2 respectively. The ice shelves are several hundreds of metres thick and the ocean areas under them are important for the formation of cold, dense Antarctic Bottom Water (AABW),

Same source.

[minus 9]

can anyone tell me how i add links to my comments. please

[cyclonic happiness]

All doom and gloom isn't it?

No-one can say what shall happen in 15 years time, just as they couldn't 15 years ago or 30 years ago.

The public of the world are getting tired of the constant 'scare' stories that haven't really come true.

"Isn't the sea level actually dropping slightly atm?"

That sort of thing, it just makes me more and more confused.

I think I'll just go with my instincts

[knocker]

can anyone tell me how i add links to my comments. please

One way of doing it. Copy and paste the URL and the type in at the beginning and {/url] at the end. But I think most use the link function at the top of the message.

Cheers

Malcolm

Edited September 14, 2012 by knocker

[knocker]

All doom and gloom isn't it?

The public of the world are getting tired of the constant 'scare' stories that haven't really come true.

I think I'll just go with my instincts

Not according to the latest Canadian poll. What are your instincts that appear to be overiding hundreds of scientific papers?

[androcles]

This may just sound a pretty dumb question so please bear with me. If the ice is melting anywhere on land, then presumably the sea levels will rise. If it's melting on the oceans then the sea levels will remain unchanged.

Now I do not know this because I haven't looked into it in any great depth, but I have not seen any evidence of any sea levels rising anywhere. If the situation is becoming 'critical' as some would suggest, why has the level not risen? Or has it and I just missed it in Portsmouth Harbour...?

[shuggee]

Have a read here androcles:

http://ibis.grdl.noa...ries_global.php

6cm rise measured over 20 years.