Antarctic Ice Discussion

[Gray-Wolf]

Hi OSW! Yeah, sorry about the nomenclature....... I just don't want to tar all with the same brush as ,  I believe, most all of us are 'sceptics' in our endeavours to find a world view ?

 

I noted the ozone hole was smaller but some of it's reduction was put down to the atmospheric warmth that I think has brought such stormy conditions to the southern Oceans ( and caused issue with the migrant sea birds) so even though the hole must be healing these days I thin we have to accept some 'natural variation' there as well and this year has seen a big push in the 'recovery' direction.

 

I think that the impacts from the hole were near instant weren't they? The impact on upper atmosphere temps translates down over a matter of weeks does it not? (like a SSW?) so the impacts , or lack of, from a smaller hole should translate at the same speed?

 

Somehow it appears that the whole globe has seen a 'tweak' to the conditions that has been around for a while? We see different patterns across the north for our flood/heatwave/drought areas and we see Australia coming off record heat last summer into a record winter with now record spring wildfires and the prospect of another hot summer? Maybe it is an 'ocean heat' thing with Aussie prospects for another hot summer being given as driven b high SST's around them? Our Zonal run is also being put down to the high sst's out in the Atlantic (and the lack of 'canes must have left a lot of heat in areas where storms should have soaked up some of that heat???).

 

Back to the ice. If we have seen a more rapid transport of 'inner ice' into the southern ocean at a speed which matches it's melt out then we will have a band of thin ice now around the coasts (sat eyeballing seems to confirm this?) As spring advances the outer melt will overcome the transport of ice and so levels will rapidly drop to 'normal' levels ( I think we're seeing this now?) but this leaves the band of much thinner inner ice. Once the warmth reaches this 'inner band' then it will melt out far more rapidly than 2m FYI would leaving open water for quite a stretch around the coast.

 

Ice increases at min have been centred around Weddell in recent years (areas off Ross are in decline) so maybe we need look at any ice 'extension' in that area to see how changes might impact ice levels at min this year? If a reduction in the ozone hole has impacted the circumpolars but sst's have increased 'general storminess' in the southern ocean then we may see more ice heading north under storm systems (or driven south onto the coastal strip and slabbing there) and not 'trapped' inside the circumpolar belt where it has a better chance of survival.

 

I will be seeing if we get a big polynia in Weddell this season as I think the reduction of this feature in recent ears has really helped keep ice levels high at min.

 

After a really interesting Arctic summer we may well be treated to a really interesting Antarctic summer this year?

 

As for Fours little poke I think it interesting to try and imagine how a 'blip' in conditions there might impact ice levels. If anything it would lend credence to our understanding of the workings of the sea ice there if we could predict the outcome there this year ( and give reasons for our punt). As some folk are fond of saying 'The Earth is always changing' ...... if some of those changes are constant, and in a single direction, then it should be easier to suggest outcomes when we get a heads up on where the 'natural forcings' are taking us? 

[knocker]

'Tiger stripes' underneath Antarctic glaciers slow the flow

Narrow stripes of dirt and rock beneath massive Antarctic glaciers create friction zones that slow the flow of ice toward the sea, researchers at Princeton University and the British Antarctic Survey have found. Understanding how these high-friction regions form and subside could help researchers understand how the flow of these glaciers responds to a warming climate.

 

 

http://www.princeton.edu/main/news/archive/S38/38/34Q39/index.xml?section=topstories

[knocker]

China spreading its influence in the Antarctic. Where is it not?

 

Polar power play

http://www.economist.com/blogs/analects/2013/11/china-antarctic

[Styx]

We see reports from Australia of migrating bird deaths due to them encountering high winds at the end of their journeys ( one of the windiest in years) so we have coasts stripped clean of ice ( which then re-formed 'cause it's still very cold there what with the katabatic winds streaming off the cold interior) and ice 'extent' remaining high as the ice is driven outward.

 

 

Love your posts Gray-Wolf, but where did you see reports about bird mortality associated with high winds, must have missed it, but I'm intrigued..

[Gray-Wolf]

http://www.theage.com.au/environment/animals/dead-birds-not-just-a-freak-event-20131030-2wgzd.html

 

There you go styx.

[Styx]

http://www.theage.com.au/environment/animals/dead-birds-not-just-a-freak-event-20131030-2wgzd.html

 

There you go styx.

 

Good going, thanks .. the phenomena does get an airing in the Tasmanian press occassionally...the 'wrecks' are also a widespread and reoccuring event stretching along the birds migratory route to the Arctic. Japan and North America get them too.  Nothing special about the windy season this year however - appeared to be a return to what it once was at this time of year - after a noticable lull over recent years. http://www.parks.tas.gov.au/index.aspx?base=5100

[knocker]

Vast Antarctic iceberg 'could threaten shipping'

UK researchers have been awarded an emergency grant to track a vast iceberg in Antarctica that could enter shipping lanes.

 

Latest images show several kilometres of water between the iceberg, estimated to be about 700 sq km (270 sq miles), and the glacier that spawned the block.

 

The £50,000 award will fund a six-month project that will also predict its movement through the Southern Ocean.

 

The icy giant broke away from the Pine Island Glacier (PIG) in July.

 

"From the time it had been found that the crack had gone all the way across in July, it had stayed iced-in because it was still winter (in Antarctica)," explained principal investigator Grant Bigg from the University of Sheffield.

 

"But in the last couple of days, it has begun to break away and now a kilometre or two of clear water has developed between it and the glacier.

 

 

http://www.bbc.co.uk/news/science-environment-24912233

[Gray-Wolf]

This is another 'quirky' thing about 'sea ice'. When you see huge bergs like this break off from a shelf ( well beyond 'natural variation') then the 'mask' for sea ice calcs is altered. This means the amount of sea ice possible around the coast increases. with the loss of the  likes of the larsen complex, Wilkins, PIG you start to amass a large area that, being at the shore, will re-freeze come winter but become part of the 'sea ice' figures.

 

Should the ozone recovery bring to an end the 'extensions' in certain sea ice areas we will still see a 'higher' figure of the ice due to the areas now open to ice cover that were once classed as 'land areas'. imagine the figures when the likes of Ross give way ( area of France) to the figures???? Will some wit still be holding it up as an 'increase' or will folk see it for what it is?

 

EDIT: Does the 'berg' now count as sea ice whilst it remains in the area used to measure such? Thats it counted once as 'sea ice' and then twice as it's area left open to the ocean come re-freeze..................

Edited November 13, 2013 by Gray-Wolf

[knocker]

Which graph is the most significant?

 

 

 

[stewfox]

This is another 'quirky' thing about 'sea ice'. When you see huge bergs like this break off from a shelf ( well beyond 'natural variation') then the 'mask' for sea ice calcs is altered. This means the amount of sea ice possible around the coast increases. with the loss of the  likes of the larsen complex, Wilkins, PIG you start to amass a large area that, being at the shore, will re-freeze come winter but become part of the 'sea ice' figures.

 

 

 

That's a 'new one' to explain the near record ice extent , more ice bergs breaking of and 'adding to the extent'

 

 

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

 

Of course much of the sea ice around the coasts hasn’t even started to melt out yet

 

http://arctic.atmos.uiuc.edu/cryosphere/antarctic.sea.ice.interactive.html

Edited November 13, 2013 by stewfox

[stewfox]

Which graph is the most significant?

 

 

Obviously the extent is more significant with a 10% Change then a unproved (Old NASA photo) showing a 0.001%  change in Antarctic ice mass

 

Its like comparing the weight loss of a Whale against the weight lost of a Dragon Fly.

 

Its like Saying the whale has lost a 0.06 ounces which is equal to the dragon fly's gain all is well.

 

 

Area = 13,700,000 km2 covered with ice
Mean ice thickness: 1.6 km
Ice volume: 21,920,000 km3

1 km3 of ice weighs 1 billion metric tons

 

 

 

Edited November 13, 2013 by stewfox

[knocker]

Seismic detection of an active subglacial magmatic complex in Marie Byrd Land, Antarctica

Numerous volcanoes exist in Marie Byrd Land, a highland region of West Antarctica. High heat flow through the crust in this region may influence the stability of the West Antarctic Ice Sheet^{1, 2, 3, 4}. Volcanic activity progressed from north to south in the Executive Committee mountain range between the Miocene and Holocene epochs, but there has been no evidence for recent magmatic activity^{5, 6, 7}. Here we use a recently deployed seismic network to show that in 2010 and 2011, two swarms of seismic activity occurred at 25–40 km depth beneath subglacial topographic and magnetic highs, located 55 km south of the youngest subaerial volcano in the Executive Committee Range. We interpret the swarm events as deep long-period earthquakes based on their unusual frequency content. Such earthquakes occur beneath active volcanoes, are caused by deep magmatic activity and, in some cases, precede eruptions^{8, 9, 10, 11}. We also use radar profiles to identify a prominent ash layer in the ice overlying the seismic swarm. Located at 1,400 m depth, the ash layer is about 8,000 years old and was probably sourced from the nearby Mount Waesche volcano. Together, these observations provide strong evidence for ongoing magmatic activity and demonstrate that volcanism continues to migrate southwards along the Executive Committee Range. Eruptions at this site are unlikely to penetrate the 1.2 to 2-km-thick overlying ice, but would generate large volumes of melt water that could significantly affect ice stream flow.

 

 

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1992.html

 

The press release

 

Volcano discovered smoldering under a kilometer of ice in West Antarctica

Its heat may increase the rate of ice loss from one of the continent’s major ice streams

 

http://news.wustl.edu/news/Pages/25611.aspx

[knocker]

Early-career investigator discovers current volcanic activity under West Antarctica

 

Scientists funded by the National Science Foundation (NSF) have observed "swarms" of seismic activity--thousands of events in the same locations, sometimes dozens in a single day--between January 2010 and March 2011, indicating current volcanic activity under the massive West Antarctic Ice Sheet (WAIS).

 

Previous studies using aerial radar and magnetic data detected the presence of subglacial volcanoes in West Antarctica, but without visible eruptions or seismic instruments recording data, the activity status of those systems ranged from extinct to unknown. However, as Amanda Lough, a doctoral candidate at Washington University in St. Louis, points out, "Just because we can't see ...below the ice, doesn't mean there's not something going on there."

 

 

http://nsf.gov/news/news_summ.jsp?cntn_id=129660&org=NSF&from=news

[knocker]

Saturday Space Sight: Pine Island Glacier

 

http://science.dodlive.mil/2013/11/30/saturday-space-sight-pine-island-glacier/

Edited December 1, 2013 by knocker

[knocker]

Not relevant but...................................

 

Scott's hut as he left it.

 

http://jynnne.tumblr.com/post/69023733067/polar-climates-are-a-preservationists-dream-with

[knocker]

Reducing Salt Is Bad for Glacial Health, NASA Finds

 

A new NASA-led study has discovered an intriguing link between sea ice conditions and the melting rate of Totten Glacier, the glacier in East Antarctica that discharges the most ice into the ocean. The discovery, involving cold, extra salty water -- brine -- that forms within openings in sea ice, adds to our understanding of how ice sheets interact with the ocean, and may improve our ability to forecast and prepare for future sea level rise.

 

http://www.sciencedaily.com/releases/2013/12/131206143614.htm?utm_source=twitterfeed&utm_medium=twitter&utm_campaign=Feed%3A+Cryonews+%28CryoNews%29

[mikeworst]

Those glaciers have other things to worry about. Seems that a new all-time low global temperature of -91.2 c has been recorded in Antarctica. Tad chilly,what?  http://german.ruvr.ru/news/2013_12_08/Rekordkalte-in-Antarktika-2913/

[Gray-Wolf]

http://www.accuweather.com/en/aq/dome-fuji-station/2273694/month/2273694?monyr=12/01/2013

 

I'm struggling Mike, can you give us the data the record was set please. I've gone through this years temps and can't find it? Is it a 2m temp or was it at height?

[mikeworst]

Seems the NSIDC is going to make this public at the AGU, so lets see.

[knocker]

Minus credibility? Antarctic record low temperature disputed

 

American scientists claim they have found the coldest place on Earth - in Antarctica, where temperatures can fall below -91C. One Russian scientist calls this into question, pointing out the new record was made using remote measurements.

 

American researchers from the US National Snow and Ice Data Centre (NSIDC) prepare to make public satellite temperature measurements data which maintains that a record temperature of -91.2°C was registered in Antarctica on August 3, 2004, near the Japanese Dome Fuji station, situated on the Valkyrie Dome in the heart of the White Continent.

 

The preface of the report prepared for the American Geophysical Union's annual meeting in San Francisco suggests that the space-borne Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard NASA’s satellites registered the record low temperature “during periods of extensive clear sky conditions†nearly a decade ago “along the highest section of the East Antarctic ice divide.â€

 

The report also maintains that the “winters of 1997, 2001, 2003, and 2004 showed several temperature minima below -90°C.â€

“It is likely that record cold sites identified by the data have small areas within them that are significantly colder than the grid cell mean,' a published summary of the findings said.

 

So far the lowest temperature was also measured in Antarctica, at the then-Soviet Vostok station, where during the winter of 1983 a record –89.2°C was officially registered.

 

http://rt.com/news/antarctica-temperature-record-questioned-922/

[Gray-Wolf]

Ahh!, so a low temp measured in 04' is what is being disputed? So a very small , localised 'cold spot' is what is being talked about here ( remotely sensed) and not a 'New record low' set at one of the stations that take daily records ( and so a data point in a series of recordings leading toward a 'trend' in temps?).

 

Basically we could say " we've now, via the use of satellites, tracked down the coldest 'cold spot' on the planet which could challenge the old record set at the vostok station....."?

 

Did anyone else misunderstand what the statement was claiming or is it just me being extra dim today?

[Gray-Wolf]

http://www.webwire.com/ViewPressRel.asp?aId=183714#.UqhDU_RdVB0

 

So not only are satellites enabling us to track down the lowest temperature ever measured on the planet ( see above) they can also now better track the ice losses from the ice sheets there. It appears that 'the only way is up' for mass loss from West Antarctica? When you see folk pointing at sea ice levels getting higher over the past 20 years try and balance that temporary gain ( the 'extra ice melts each summer) with this constant , year on year, 'loss' from the land ice behind and then you decide which is of most significance.

Edited December 11, 2013 by Gray-Wolf

[Methuselah]

Fair play to the 'Sceptics,' though...they always question satellite data.

[stewfox]

http://www.webwire.com/ViewPressRel.asp?aId=183714#.UqhDU_RdVB0

 

So not only are satellites enabling us to track down the lowest temperature ever measured on the planet ( see above) they can also now better track the ice losses from the ice sheets there. It appears that 'the only way is up' for mass loss from West Antarctica? When you see folk pointing at sea ice levels getting higher over the past 20 years try and balance that temporary gain ( the 'extra ice melts each summer) with this constant , year on year, 'loss' from the land ice behind and then you decide which is of most significance.

 

You would need to look at the whole of Antarctica not just 20% of it

 

 

http://en.wikipedia.org/wiki/East_Antarctica

 

http://www.climatedepot.com/2013/09/01/antarctic-ice-sheet-growing-study-mass-gains-of-the-antarctic-ice-sheet-exceed-losses/

[knocker]

I think if I was linking to something produced by CFACT Stew I would check it with three with other sources and make sure my zip was done up. They are the ones who gave that insane speech in Warsaw. Some of their products are straight out of the looney bin.

 

http://www.cfact.org/

Edited December 11, 2013 by knocker