Antarctic Ice Discussion

[Gray-Wolf]

Here's a fuller report of the feb article on the link between Aussie drought and increased Antarctic snowfall;

http://www.watoday.com.au/wa-news/antarctic-snowfall-linked-to-southwestern-drought-20101025-1708s.html

the 750yr record has nothing close to the increases that have been measured over the past 30yrs......odd that, last 30yrs?

[jethro]

There's nothing really odd about having satellite measurements from 30 years ago .....

What's really odd is that the post satellite era is giving us such accurate measurements that we can tell we're in unique times. Couldn't possibly be influenced by not being able to measure with such fine detail, all the various proxy data, could it?

If I were a scientist I think I'd be beginning to ponder on the 30 year coincidences which keep cropping up.

[Yorkshiresnows]

<br />There's nothing really odd about having satellite measurements from 30 years ago .....<br /><br />What's really odd is that the post satellite era is giving us such accurate measurements that we can tell we're in unique times. Couldn't possibly be influenced by not being able to measure with such fine detail,  all the various proxy data, could it?<br /><br />If I were a scientist I think I'd be beginning to ponder on the 30 year coincidences which keep cropping up.<br />

<br /><br /><br />

Spot on Jethro,

Y.S

[blitzen]

http://www.iceagenow.com/Antarctica-Highest_September_snowfall_on_record.htm

[knocker]

http://www.iceagenow...l_on_record.htm

Maybe a slight perspective on this.

Reporting in the journal Geophysical Research Letters scientists from British Antarctic Survey (BAS) and NASA say that while there has been a dramatic loss of Arctic sea ice, Antarctic sea ice has increased by a small amount as a result of the ozone hole delaying the impact of greenhouse gas increases on the climate of the continent.

http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=838

[Optimus Prime]

One minute the Ozone layer was increasing the melt in the Antarctic...now the Ozone layer is preventing a large scale thaw? I have to say the human mind needs more studying then the climate.

[barrel1234]

My common sense siren is going off in my head reading that ozone layer has such a huge impact on Antarctic Ice, I think this is a perfect example of researchers studying a specific thing getting caught up in thinking that its the main driver and having blinkers on to other factors going on in our complex climate.

[knocker]

My common sense siren is going off in my head reading that ozone layer has such a huge impact on Antarctic Ice, I think this is a perfect example of researchers studying a specific thing getting caught up in thinking that its the main driver and having blinkers on to other factors going on in our complex climate.

I'm not sure I agree with that.

The first comprehensive review of the state of Antarctica’s climate and its relationship to the global climate system is published this week (Tuesday 1 December) by the Scientific Committee on Antarctic Research (SCAR). The review - Antarctic Climate Change and the Environment – presents the latest research from the icy continent, identifies areas for future scientific research, and addresses the urgent questions that policy makers have about Antarctic melting, sea-level rise and biodiversity.

http://www.theozonehole.com/ozonehgood.htm

[BornFromTheVoid]

Antarctic ice sheets more stable than first thought?

http://www.newscientist.com/article/dn19752-weakening-ice-sheet-could-protect-itself-from-the-sea.html

[Gray-Wolf]

Antarctic ice sheets more stable than first thought?

http://www.newscient...om-the-sea.html

But only if the whole sheet starts to melt at once.......

And if my uncle had been a woman he'd have been my Aunty.....

As it is we have localised 'melt' and transport and melt across the continent. As we saw from the recent study of shells the passage that separates East and west Antarctica was open (or partially open) 125,000yrs ago so the 'meltdown process' seems to be a process of stages and not a steady, ongoing melt across the whole sheet?

I would guess at ice shelfs disappearing followed by a rapid 'reorganisation of the glacial outlets (once their buttresses have gone) followed by lowland melt revealing the rocks below providing further 'heating' to allow the melt to move upslope.

If this is the process then we will not see isostatic rejuvenation playing the role outlined in the article as the changes are too rapid?

As for isostatic rejuvenation have we heard any more about the paper we had in late spring that said we had over-estimated ice loss from Greenland /Antarctica due to our inability to gauge the rate of uplift as ice mass is removed?

I'd have expected some intensification in studies to prove/dis-prove the contents of the paper?

[Michael Hauber]

Both the reduction in weight of the ice sheet pressing the rock down, and the reduction in gravity pulling the ocean towards the ice sheet are basic facts of physics that don't need to be proven/disproven.

The only question is how strong the effect is. The article doesn't state how great the effect is, and a general rule of thumb I use for the media is that if they leave out an important piece of information, it is usually because that piece of information is boring (eg the effect may be only a 5% reduction and hardly worth mentioning). Either that or they just don't know how strong the effect will be.

[Gray-Wolf]

"One of the warning signs that a dangerous warming trend is under way in Antarctica will be the breakup of ice shelves. on both coasts of the Antarctic Peninsula, starting with the northernmost and extending gradually southward. These ice shelves should be regularly monitored by LANDSAT imagery. "

The above is part of the conclusion to the attached paper;

http://tintin.colora...Nature_1978.pdf

From back in 1978. Seems we are well into the period we were warned about (no mention of impending ice ages you note?)

EDIT: And I found this sequence of Pine island calving;

If you look at the first image you'll note the crevace where the breakup will occur. Now compare that to 'My Crack' on Ross;

The Pine Island berg was 22 miles long, the Crevace on Ross is about 1/2 the size of France.

Edited November 25, 2010 by Gray-Wolf

[Gray-Wolf]

Looks like we will have a very early total melt out of the sea ice around Antarctica over the next 2 weeks? This frees up the ice shelfs to further collapse. Would anyone like to hazard a guess as to which areas we will see losses in now Wilkins has gone? I'm thinking either Pine island or Ross are due some 'normal' losses (no big break offs for a few years from either) but will there be bigger slumps than normal?

Pine island is no longer sat on the ocean ridge and so has been eaten back below the water line. Once the 'damping effects of the sea ice are removed then the shelf is free to be 'waggled' by Southern ocean swells (like waggling a loose tooth).

[songster]

Looks like we will have a very early total melt out of the sea ice around Antarctica over the next 2 weeks?

Why do you say that? Area is bang on average according to CT, while extent is well above average according to NSIDC. Not saying you're wrong, just wondering what your data source is.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png

http://nsidc.org/data/seaice_index/images/daily_images/S_stddev_timeseries.png

[Gray-Wolf]

Just looking at the amount of 'thin/sparce ice' we see on C.T. We only have Weddel that looks pretty solid , the rest is in melt and drifting into the southern Ocean?

[picog]

Why do you say that? Area is bang on average according to CT, while extent is well above average according to NSIDC. Not saying you're wrong, just wondering what your data source is.

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

http://nsidc.org/dat..._timeseries.png

Looks pretty average at the end of 2010?

[Gray-Wolf]

So all this talk of 'growth' is not true?

Average?

[Hiya]

So all this talk of 'growth' is not true?

Average?

In an average there generally tends to be numbers above and below the average value over a given period, yes it is on the average just now.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png

Look at the anomaly line, if we were to calculate a new average from that the average value would increase and the anomaly line would shift downwards. Since the sea ice in Antarctica is increasing:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png

So the average increases and there will be a greater probability of a negative anomaly just through ordinary variation. Yet I bet you still crow about below average.

[Gray-Wolf]

In an average there generally tends to be numbers above and below the average value over a given period, yes it is on the average just now.

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

Look at the anomaly line, if we were to calculate a new average from that the average value would increase and the anomaly line would shift downwards. Since the sea ice in Antarctica is increasing:

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

So the average increases and there will be a greater probability of a negative anomaly just through ordinary variation. Yet I bet you still crow about below average.

lol!

Yup! Sure diddly!

I'm (obviously) being a little naughty......start the New Year in a new 'stylee'?

Cryosat2 is now bringing data as to 'mass balance' of both ice sheets down there and they (I believe) are the important element down there? Seasonal sea ice comes and goes?

[Gray-Wolf]

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png

All this talk of 'record Antarctic sea ice'.

I've been looking at the 'plot's' (like C.T. above) and it seems that 're-freeze' is where the 'extra ice occurs most (before ice max?) and that the 'melt' follows the 'average ' line quite nicely?

[knocker]

And this has nothing to do with billions of tones CO2 being dumped into the atmosphere? Get real. I agree with GW

New research indicates the impact of rising CO₂ levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, causing researchers to estimate a collapse of the West Antarctic ice sheet by the year 3000, and an eventual rise in the global sea level of at least four metres

http://www.eurekaler...c-cct010611.php

Edited January 9, 2011 by weather ship

[jethro]

And this has nothing to do with billions of tones CO2 being dumped into the atmosphere? Get real. I agree with GW

New research indicates the impact of rising CO₂ levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, causing researchers to estimate a collapse of the West Antarctic ice sheet by the year 3000, and an eventual rise in the global sea level of at least four metres

http://www.eurekaler...c-cct010611.php

No.

That research (based upon reading the above link) demonstrates a "what if" scenario based purely upon CO2 emissions.

It's an exercise in running a computer model, no more and no less. It gives no realistic idea of what the future holds, being based on speculation and supposition.

We already know CO2 has a long term impact, we already know that stopping emissions over-night won't instantly negate the CO2 we've already pumped out - we've known that for years. This isn't new knowledge nor does it give any meaningful insight to the future and to be honest, it beggers belief that this is being touted as new. It isn't.

[Gray-Wolf]

What many folk miss ,Jethro, is that the CO2 already up there is not just 'warming'' the world but helping bring energy to bare on areas that will 'aid and abet' that warming?

What we see in the Arctic right now being a point in question. With temp records falling across West Greenland and East Canada (and Hudson /Baffin still less than 1/2 frozen) we can see that any 'end of winter' cold cannot do the Job of Oct to spring 'deep cold'. With 'less work to do come spring we can envisage even warmer SST's as heat ,formally used melting ice, just heats the sea/bay area.

The lack of 'ice' ,we know, impacts 1,500km inland so how much permafrost is in for an 'early melt' this summer?

With twice as much CO2 waiting in deep freeze across the north any move towards a 'meltdown' just compounds our peril by elevating CO2 levels further (with lots of 'methane' to speed up any warming).

[pottyprof]

New research indicates the impact of rising CO₂ levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, causing researchers to estimate a collapse of the West Antarctic ice sheet by the year 3000, and an eventual rise in the global sea level of at least four metres

Personally, I just don't understand these doom scenarios. I agree with some sea level rise as it goes hand in hand with warmer global climates. Even a one metre rise would not be beyond natural variation.

Sea level was close to its present level 1000 years BP, then rose to perhaps 0.9 m above around 700 BP. This period of sea-level rise coincided with a period of warming named the Little Climatic Optimum. The transition to the Little Ice Age, when sea level stood lower, was marked by a transition around 690 BP when sea level (and ground temperatures) fell rapidly.

http://cat.inist.fr/?aModele=afficheN&cpsidt=2129912

[laserguy]

And this has nothing to do with billions of tones CO2 being dumped into the atmosphere....... causing researchers to estimate a collapse of the West Antarctic ice sheet by the year 3000, and an eventual rise in the global sea level of at least four metres

Yes that's right. And the(possible) collapse of the WAIS in 3000? Now I'm really quaking in me boots. Do the alarmists have an immortality pill that they're not letting on about?