Antarctica

[BLAST FROM THE PAST]

In my more paranoid/clear thinking moments I do find myself pondering whether there really is a global 'us' and 'them'. I know that there are multiple organisations representing world nations but I'm thinking more of the tier above govt.s

If we do face a global disaster would you let the populace know the grim realities or would you choose to manage the disaster instead (and doing the cleanup without facing 1st world 'meltdown' as folk panic at the prospects) and enhance the chance of a 'smooth' transition through the period of mass death/relocation and a rapid 're-boot' to societies remnants?

Whether fantasy or other the loss of 2/3 of the global population would be a meaningful way of avoiding the worst case scenario's we face on a number of fronts (Climate change,feeding 6 billion, peak oil etc.)

Sounds like 'the nine times rule'

BFTP

[Gray-Wolf]

So we have some of the lowest temps recorded posted from inside Antarctica yet the sea ice extent continues to fall. Again I would advise folk to have a look at the coasts of Antarctica (where MODIS allows) and then come back and explain why there is so much open water around the coasts.

Is there warm water upwelling along the coasts or something???

[BARRY]

Yet again for the second time this year,the Australia Antarctic Davis station breaks it's coldest record now at -38.3c

[BARRY]

a new record of -39.0c

[Nick L]

But why isn't the ice recovering?

[BARRY]

But why isn't the ice recovering?

recovering from what,mans knowledge which is frankly very limited or mother nature's normal cycle of which we are still learning

[Gray-Wolf]

I do wish someone else would take a look at the Antarctic Coastline. The amount of open water there is, for me, a first. There would also seem to be lots of 'dark ice' (as we saw oop north before the pack gave way and melted) and fissureing.

Last years pack was well fragmented by now but it was pristine white (not slushy grey) and connected to the coast throughout.

If what I am seeing is 'correct' then we might expect a very fast breakup in December. The most puzzling thing is that it has been another 'cold' winter on the Continent but the sea is still refusing to freeze at the coasts(and the ice shelves are collapsing still in mid-winter???).

Are we finally seeing the worlds oceans breaking through the circumpolar current and flooding the area with (relatively) warm waters??? I did hear this mooted as reason for the 'Wilkins' collapse and now all of this open water at the coast has me wondering......

[Gray-Wolf]

I take it that the lack of increase in 'views' on this thread over the past week, and the extra posts since I last posted, means that most folk either don't care about the South or don't know enough to comment.

We keep getting posts claiming record temps in the interior but where it matters, on the coastlines where the protective shelves live, we are seeing lower ice levels than last year (which was a warmer winter than this years) and the 'average' ice levels for this time of year.

Doesn't this seem odd?

Fascinating though the meltdown up north may be the continuance of our society ,as it exists today, depends upon the retention of the ice shelves around Antarctica.

We ,by now, must be hardened to scientists telling us that things are happening a lot faster than predicted and were this trend to continue in Antarctica then we will find ourselves in a rapidly altering global situation.

EDIT: Looking at the NSIDC plots we went from an above average year, up to early July, to a below average year from then on. So , basically as the winter deepened ice levels did not increase as they ought, in fact at times they shrank (whist we got reports og record 'cold' from inside Antarctica.

The amout of 'open water' at the coasts this year is also a first for me (and I've been doing this for a number of years now) and we have heard no explaination as to why this should be so.

So, if you think the Arctic is a worry then spare some time to gen. up on what a similar melt in the South would mean to us all.

The influx of the southern oceans into the 'protected belt' around Antarctica (protected by the circumpolar current) will mean a rapid breakup of ice shelves around the continent (and not just the bit sticking up into the southern oceans) and this , in turn, will lead to the same acceleration in ice drain from the glaciers feeding the shelves as we saw in the Peninsula. Most of the planets fresh water is held in these glaciers and the ice sheets that feed them.

We are now approaching the Southern 'melt season' and so will find out ,in rapid order, if warmer waters are now perculating around the Antarctic coasts both by the speed of melt from the coastline (where the warmer waters would be forced into the surface layers) and the collapse of ice shelves/glacier snouts around on the WAIS.

Edited September 11, 2008 by Gray-Wolf

[Mondy]

New Scientist: Sea Ice Increases Due to Global Warming

[Gray-Wolf]

New Scientist: Sea Ice Increases Due to Global Warming

I think you may need to look at the NSIDC plot for this year to see if this holds water (or ice :lol: ) for the last freeze season.

For whatever reason, though a cold winter on the continent, the cold has not transfered onto the surrounding oceans. In fact the season started with 'above average ' ice levels and this has fallen back as the southern winter progressed

with periododic fluctuations.............things do seem a little 'Hayoka' down there don't they.

[stewfox]

I take it that the lack of increase in 'views' on this thread over the past week, and the extra posts since I last posted, means that most folk either don't care about the South or don't know enough to comment.

Fascinating though the meltdown up north may be the continuance of our society ,as it exists today, depends upon the retention of the ice shelves around Antarctica.

Two things keep it out of the media

Nothing adverse is happening down there , the inner areas maybe a bit cold some more sea ice in some places less in others

The other there are no cute polar bears

Re the Artic

If all the ice floating in the oceans of the world melted this morning, the effect on sea level would be zero. [Archimedes hydrostatics.] however people get excited if a bit more of the Artic melt then usual

Why ?

The last thing I saw about the Antarctic was a paper publish in a American scientific journal re how the coast of Florida would look if the Antarctic melted

Very 'scientific'

[Gray-Wolf]

Two things keep it out of the media

Nothing adverse is happening down there , the inner areas maybe a bit cold some more sea ice in some places less in others

The other there are no cute polar bears

Either we are just 'getting the hang' of measuring things down there or there is plenty of 'adverse' happenings taking place over the last 15yrs.

We have the B.A.S.'s dire warnings the "the sleeping giant is awakening" and the spectacle of major ice shelfs collapsing, and this year collapsing in a way unseen before.

We have upland melt to the rear of Ross ice shelf and on up around the peninsula.

We have 'sub-ice lakes filling' and emptying heaving up 2km of ice sheet many metres and vast sub ice streams flowing below the glaciers.

We have a 'new' climate establishing on the peninsula.

I think Penguins are cute too and the slumped of shelfs have blocked their access to open ocean causing major problems in their breeding colonies.

--------------------------------------------------------------------------------------

Because we were promised for so long that the south was 'safe' and isolated from the rest of the warming we seem to forget it.

The way Wilkins collapsed this winter, both it being mid-winter and it's mode of disintegration, raises many concerns in myself not least that the circumpolar current has been breached by warmer bottom waters and will now be able to impact on ALL the Antarctic coastlines (and their shelfs).

In the past and ice shelf either fractured into a massive berg and drifted off or collapsed along the pre-existing weaknesses in the shelf (the giant crevasses that are remnants from its movement as a glacier) but Wilkins appeared to melt out from below....in mid-winter....and those darling Seals with their thermometer swimming caps are throwing up data that shows that warmer waters are present now ,to great depths, even at mid-winter.

In the way folk have been surprised at the rapidity of the 'end game' up north once the coastal fringe is eroded (and it's shelfs) then we can expect massive and rapid ice loss from the inner continent even if it (the inner continent) remains cold. In a way the size of the ice sheets in Antarctica are their own worst enemy allowing pressures at depth that keep water liquid and masses that gravity cannot ignore. Take away the 'Girdles' that are holding the process at bay (the fringing shelfs) and we will suffer the initial phase of collapse that is already stored up there and ready to go. I very much suspect that thereafter we will see a 'domino effect' as the lost mass leaves 'open areas' for more ice sheet to slump into.

[Gray-Wolf]

I that it?

Southern max reached?

If so what a strange year darn sarf.......????

Mid winter ice shelf collapse, seal caps showing deep upwelling of warm waters all set against the backdrop of some record cold land temps.

I would suggest keeping a weather eye on developments as the melt season progresses as we should see the final collapse of Wilkins and get more of an idea as to how far away from the peninsula the warming oceans have now reached.

The clamour to get as much data from the seal caps should bring out some interesting info on the waters now lapping around Antarctica and ,to my mind, bring forth plenty of 'updated projections' of how we now expect the continent (esp. the fringing shelfs) to react to a warming ocean.

Edited September 22, 2008 by Gray-Wolf

[Gray-Wolf]

By the look of the amount of 'grey water' around the coasts I'd imagine the current rapidity of melt to continue. The (again) fragmentation of the rest of the ice would allow quite rapid transportation on the Katabatic winds into the southern oceans and it's eventual demise.

we may see two separate processes at work here this year with warm upwelling at the coasts allowing large polynia's to open followed by the rest of the pack breaking apart (quite rapidly ) and being blown into the warmer ocean beyond the coastal belt.

Of course of much more interest are the shelfs and how they cope with any warm water inundations.

Not only up north now has interests piqued!

[Gray-Wolf]

http://www.independent.co.uk/environment/n...ins-950837.html

To the north ,the Polar Bear, to the south, the Penguin.

Again we are measuring abnormally warm waters in what should be cold water currents. The poor critters above are probably as valuable as the 'seals in caps' in illustrating that something 'not good' has started to occur in the waters around Antarctica and the ocean currents that hail from the region.

I cannot emphasise enough the catastrophe that Antarctic shelf loss will precipitate and if warmer waters have started peculating closer in to the shore there then we are all in big do-do's.

[jethro]

Vostok station data back to 1958, everything you ever wanted know....

http://www.aari.aq/data/data.asp?lang=0&station=6

Surface air temperature ©

2. Ground temperature ©

3. Surface maximum air temperature ©

4. Surface minimum air temperature ©

5. Relative humidity (%)

6. Precipitation (mm)

7. Surface wind (m/s)

8. Atmospheric pressure on met site height level (hPa)

9. Total cloudness (tenths)

10. Low cloudness (tenths)

11. Surface albedo (%)

12. Sunshine duration (hours)

13. Total solar radiation data (MJ/m2)

14. Air temperature (С) at 600 hPa level (00 GMT)

15. Air temperature (С) at 500 hPa level (00 GMT)

16. Air temperature (С) at 300 hPa level (00 GMT)

17. Air temperature (С) at 200 hPa level (00 GMT)

18. Air temperature (С) at 100 hPa level (00 GMT)

19. 600 hPa geopotential height (m) (00 GMT)

20. 500 hPa geopotential height (m) (00 GMT)

[Gray-Wolf]

http://amrc.ssec.wisc.edu/iceberg.html

And here's a nice site showing vaious shelf areas (plus bergs) and the current conditions from the meto stations positioned around them.

You should note how much 'open water' is visible whilst he temps are well into the -degree's C.

As has been mentioned both here and on the various arctic threads the 2m temps pale into insignificance when you look at the temps of the first few metres of Ocean and the impacts it imparts (Like the Wilkins shelf disintegration over the last Antarctic winter).

People often confuse Low temps with 'Stability' when thinking of Ice shelfs (those that hold back the flow of upland glacies into the ocean), not so .

Edited October 6, 2008 by Gray-Wolf

[stewfox]

People often confuse Low temps with 'Stability' when thinking of Ice shelfs (those that hold back the flow of upland glacies into the ocean), not so .

I know you would love to see a Antartic free of ice in the next 30 years but its just not happening

Maybe just maybe the South wont play the Norths end game Your trying to melt the Antartic on your own with a lot of hot air and it isnt going to work B)

I was reading a book called Climate Change (Robert Henson) ok its bias but what books aren't

Interesting comments re the Younger Dryas period which suggested that the global cooling down south began a 1000 years before that in the North cira 14,000 years ago

Maybe the north will warm and the south wont for another 1,000 years , how many post would we get on that in a 1000 yrs ?

Edited October 8, 2008 by stewfox

[Essan]

I know you would love to see a Antartic free of ice in the next 30 years but its just not happening

It would is the Sun went Nova B)

The Antarctic ice sheet has been there for 35 million years. The coastal fringes may melt but the rest would require the sort of catastrophic warming that'd kill 90% of all life on earth .....

Shame the ice sheet didn't form until after the PETM as it'd have been interesting to know if even that was enough to completely melt it.

[Gray-Wolf]

I know you would love to see a Antarctic free of ice in the next 30 years but its just not happening

Maybe just maybe the South wont play the Norths end game Your trying to melt the Antarctic on your own with a lot of hot air and it isn't going to work B)

I was reading a book called Climate Change (Robert Henson) ok its bias but what books aren't

Interesting comments re the Younger Dryas period which suggested that the global cooling down south began a 1000 years before that in the North circa 14,000 years ago

Maybe the north will warm and the south wont for another 1,000 years , how many post would we get on that in a 1000 yrs ?

???

Stewfox, Antarctica is HUGE. It consists of 2 'islands' (West and East). The bigger (by far) is he east and the mountain ranges there would never be ice/snow free (the height alone would lead to an environmental lapse rate that would lead to sub zero temperatures no matter what occurred in the lowlands).

My concerns hinge around the collapse of the fringing ice shelves and the loss of their there supporting role for the glaciers/ice sheets behind. As we found with the loss of the ice shelves on the peninsula as soon as they (the shelves) disappear the movement tied up in the glaciers behind is released leading to rapid acceleration and collapse of the glaciers themselves. The ice sheets that feed the glaciers then loose support and slump into the old glacier and this slumped ice is then transported into the oceans.

West Antarctica, being smaller, does not have the same scale of a problem as the East. A large proportion of the EAIS (East Antarctic Ice Sheet) empties, via their glaciers, into the Ross sea via the Ross ice shelf. The ice shelf itself is not floating and so it's mass would impact dramatically on global sea levels were it to fail. I do not think we could easily imagine the weight of ice that this 'girdle' holds back and it has not been quantified (my knowledge) how much of the shelf need be 'floated' before the pressure from he rear overcame the resistance of the shelf leading to catastrophic mechanical collapse of the remaining shelf and large sections of the feed glaciers a the foot of the trans-Antarctic mountain chain.

Though the 'floating off' event is linked to sea temps the mechanical collapse is driven by it's own potential energy (as any landslide is) and is a rapid event (measured in weeks). Once in motion there is nothing to do but witness it occurring.

As you know I have been in consultation regarding one fracture line on the East side of Ross (Terminated by Roosevelt Island) and the US base at Mcmurdo already has the fracture lined with seismographs to measure it's progress and note any sudden lurches it makes. The largest past failures in the recent spate of collapses have been 1/8 of the size of the bit now appearing ready to fail.

This winters failure of Wilkins and the measured SST rises responsible (for the novel mid-winter collapse and it's novel 'mode' of disintegration) raise the spectre that the warmer southern oceans have now penetrated th Circumpolar current (and it's overturning/upwelling) via trenches along the ocean bed meaning that ALL the Antarctic coast may well start the process of ice shelf ablation. As noted above we need only loose a portion of Ross in this manner to set in motion the type of collapse I have outlined. Though initially climate driven this is not a drip,drip ,year on year event (more akin to Greenland) but a 'catastrophic failure' leading to rapid sea level rise over a period of 1 or 2 seasons.

I hope you can fully appreciate the implications of such a catastrophe.

Edited October 8, 2008 by Gray-Wolf

[Gray-Wolf]

Warmer ocean led to ice collapse

Andrew Darby,

Hobart

October 6, 2008

THE latest alarming ice shelf collapse in the Antarctic has been caused by a warming Southern Ocean melting the shelf from below.

The climate-change-induced break-up of the Wilkins Ice Shelf began last February, and has become the only documented collapse to run through the depths of winter.

At least 1350 square kilometres of ice shelf on the western side of the Antarctic Peninsula has broken off so far, and more is expected to go, say US and European scientists.

An ice bridge buttressing a large part of the Wilkins against an island off the peninsula is likely to fail soon, taking another 500 square kilometres. The collapse may not halt until the shelf, once 13,680 square kilometres, is at least halved, said Ted Scambos of the US National Snow and Ice Data Centre in Colorado.

Much of the loss of seven great ice shelves on the vulnerable Antarctic Peninsula has been blamed on surface melting.

With the area having experienced the world's greatest regional temperature rise — 2.5 degrees in 50 years — scientists have seen summer melt ponds form on top of ice shelves, before the water falls hundreds of metres through the ice, splitting it apart.

Dr Scambos said a different culprit had been found in the case of the Wilkins.

"This is the first time that it's been observed in a way that's so clearly attributable to basal melt," he said.

The conclusion was reinforced by a team led by the University of Bonn's Matthias Braun.

"We show that drainage of melt ponds into crevasses was of no relevance for the break-up at Wilkins," Dr Braun concluded in the journal Cryosphere.

He said the ice was over-stressed by buoyancy forces pressing on it from below, breaking open rifts in the shelf.

Changes in wind patterns further north have meant that, at vulnerable places such as the Wilkins, warmer water is being pushed more vigorously beneath the ice front.

"The water below the Wilkins was two, three or four degrees above the melting point of sea water," Dr Scambos said.

Edited October 9, 2008 by Gray-Wolf

[BLAST FROM THE PAST]

I knew it was nowt to do with AGW.

BFTP

[Gray-Wolf]

I knew it was nowt to do with AGW.

BFTP

???

We have years of reports of a strengthening circumpolar wind (driving the circumpolar current leading to increased cold water upwelling) driven by higher global temperatures, then reports of the mid-winter collapse with our seal thermometer-cap wearing buddies showing warm water anoms at depth under the shelf (with a promise of more data from them over a wider area) only to be told the area was 'flooded' with warm water via a trench system (bypassing the messiness of the Circumpolar current) to now be asked to believe that it is a surface wind driven phenomena breaking through the circumpolar winds/currents and driving warm water under the shelf leading to basal melting and hydraulic pummelling???

Have we had reports of a cessation of the circumpolar wind/current in a localised area for an extended period over mid-winter (the period when it is normally at it's strongest) and if not would someone suggest the mechanism that has driven this feat.

I would suggest that this is a novel occurrence (though it may become more commonplace as time moves on) and we have no historic precedence on which to base our understanding. We need be mindful of the age of Wilkins before attempting to tell us all that this is 'natural' and part of the planets great 'ballet of variance'

[BLAST FROM THE PAST]

GW its an interesting article but at this stage natural phenomena has to be the thinking as weknow oceans have very longterm cycles and as you say there is no record to relate to.

BFTP

Edited October 9, 2008 by BLAST FROM THE PAST

[stewfox]

???

Apologies post wasn't clear and appreciate the dynamics of the Antarctic as you detailed

I just found it interesting in the past that warming/cooling of the Artic /Antartic appear not to have occurred at the same time (and maybe as much a 1,000 years apart ?) Which given if the Earth was cooling or warming would be hard to figure ?? Ocean currents? Open question really if you agree with that comment

Could we see a situation with a Artic free of ice in the summer with very little change in the Antarctic (I appreciate it's a totally different beast)

The climate-change-induced break-up of the Wilkins Ice Shelf began last February, and has become the only documented collapse to run through the depths of winter.

Prefer just a change in climate , the 'word climate change induced break up', assume mans involvement

GW its an interesting article but at this stage natural phenomena has to be the thinking as weknow oceans have very longterm cycles and as you say there is no record to relate to.

BFTP