Antarctic Ice Discussion

[Gray-Wolf]

The Argo Buoys will be already sending data of the ocean profiles S.I. so we will be gathering that data?

 

I think the 'salinity drop' you refer to is over the polynia that used to both allow the formation of sea ice and drive the formation of Antarctic deep waters ( the ice loses it's salt and so a static region producing ice , which then drifts off to allow the formation of more ice), becomes a 'sink' for this water allowing for the kind of ocean circulation that drives global climate.

 

The scale of the disruption, to this process, that the 2010 collision produced is what is being studied by this, and other, expeditions. I'm sorry you cannot fully appreciate both the scale of this geographic event nor the impacts that science believes it can drive.

Edited January 6, 2014 by Gray-Wolf

[knocker]

Maritime law is very complex do you think you could be more specific?

[BornFromTheVoid]

I wonder when the alleged scientist will publish the data for the alleged decrease in salinity which they allege was the reason for the increase in ice to start with, due to the amount of alleged meltwater entering the ocean. Also will the cruise owners be held accountable under Maritime law, as surely they should foot the bill for such a costly rescue.

 

Many reasons have been suggested (and some evidence gathered) for the sea ice increases, not just salinity changes. Does it even matter to you if there's evidence or not anyway? You've shown time and time again that you simply dismiss anything that doesn't suit your position, such as ocean heat content increases, the fact that the IPCC work is done for free, that Michael Manns work is sound and supported by dozens of other studies, etc.

 

Anyway, if you want to discuss maritime law and your hopes that the people stuck on the ship were left to freeze to death (Christian morals eh), perhaps you should take that stuff elsewhere?

Edited January 6, 2014 by BornFromTheVoid

[UV-RAY]

Many reasons have been suggested (and some evidence gathered) for the sea ice increases, not just salinity changes. Does it even matter to you if there's evidence or not anyway? You've shown time and time again that you simply dismiss anything that doesn't suit your position, such as ocean heat content increases, the fact that the IPCC work is done for free, that Michael Manns work is sound and supported by dozens of other studies, etc.

 

Anyway, if you want to discuss maritime law and your hopes that the people stuck on the ship were left to freeze to death (Christian morals eh), perhaps you should take that stuff elsewhere?

Firstly Mann's work has been supported only by his peers and not independently validated, so that means jack really. Secondly I've yet to be proven wrong on ocean heat content as the search still goes on for this missing heat. Also the main reason for sea ice increasing has to be down to ocean temps decreasing, as well as other factors you yourself highlighted previously. I await the salinity results before casting further judgement but if these come back normal then the theory of melting ice being responsible is a dead duck in the water.

 

And I don't wish people to freeze to death, but these idiots brought it upon themselves and have risked the lives of others in attempts at rescuing them. 

[knocker]

Sea temps have been increasing see post.#784. If not give me some links that show the opposite. Who disagrees with Mann's work?

Edited January 6, 2014 by knocker

[Snowyowl9]

And I don't wish people to freeze to death, but these idiots brought it upon themselves and have risked the lives of others in attempts at rescuing them.

This from the telegraph agrees with you.Foolishness heading to the antartic when ice is at its thickest.http://www.dailytelegraph.com.au/news/opinion/in-the-icy-grip-of-fear-that-global-warming-is-claptrap/story-fni0cwl5-1226793282194

[Gray-Wolf]

Does anyone posting negative comments even know what a polynia is?

[jonboy]

Does anyone posting negative comments even know what a polynia is?

 

a semipermanent area of open water in sea ice. Polynyas are generally believed to be of two types. Coastal polynyas characteristically lie just beyond landfast ice, i.e., ice that is anchored to the coast and stays in place throughout the winter. They are thought to be caused chiefly by persistent local offshore winds, such as the foehn, or katabatic (downward-driving), winds typically found off the coasts of Greenland and Antarctica. Open-ocean polynyas, the larger and longer-lasting of the two types, form within the ice cover and are believed to be caused by the upwelling of deep warmer water. This type is best exemplified by the vast Weddell Polynya in the antarctic Weddell Sea.

[UV-RAY]

IMO using a polynia as the sole reason is misleading. As for kknocker statement again misleading as warmer waters have only be found entering the NE Peninsula of Antarctica  whilst SST's elsewhere have been below the average, hence the advancement of the ice. Like I said earlier lets await the data for salinity first before we all jump to conclusions, I've a feeling that these will come back negative.

 

Edit; Just seen post 784 and I've no arguments with Spencer's or Christy's work, it is amusing though how proponents of AGW will utilise data from these two when it suites but will be the first to stick the daggers in when it doesn't.

Edited January 6, 2014 by Sceptical Inquirer

[UV-RAY]

Anyway apologies to knocker for not reading the post he directed me to prior to my post. I've now got far greater worries to worry about as I've got to contact my consultant first thing tomorrow as I may have a blood clot on my leg from the TKR I had done in March. 

[knocker]

  whilst SST's elsewhere have been below the average, hence the advancement of the ice.

 

References please.

 

Sure it's not this.

 

The characteristic pattern of ice drift in the East Antarctic is westward near the continent and eastward north of the Antarctic Divergence. Data from 39 satellite-tracked buoys deployed between 1985 and 1997 have shown that the mean drift speed in the westward flow is 0.23 ms^-1 (19.8 km d^-1), and 0.17 ms^-1 (15.1 km d^-1) in the eastward flow. Ice drift speeds vary greatly with space and time, and speeds of up to 78 km d^-1 have been observed.

 

Persistent katabatic winds which drain off the continent maintain open water areas in the form of coastal polynyas by advecting the constantly forming new ice northwards. These polynyas act as "ice factories" and make a disproportionately large contribution to the total ice mass of the pack per unit area.

[mikeworst]

Yes it really is peculiar how those that endorse/believe in anthropogenic climate change are so blinded and reluctant to see/admit/accept when the evidence points elsewhere. 

[UV-RAY]

These are the latest.

 

http://www.cawcr.gov.au/staff/preid/sst/reynolds_antarctic.html

[UV-RAY]

These are the latest. http://www.cawcr.gov.au/staff/preid/sst/reynolds_antarctic.html

Anyone care to comment?

[Midlands Ice Age]

Anyone care to comment?

 

SI

 

I will.

 

I have been following this debate for a week now.

 

I think an assasination of the CACRW team is now likely!!

Wait a minute arn't they all the australian  cgw leaders in the IPCC?  LOL

 

That fact that their own organisation were showing both lower than normal SST's and they were aware of the nature of the ice in the area. according to the leader of the British Antartic effort means that they were taking major chances in a small ship.

He believes that it was inexcusable to carry on and they now have taken out of service 2 (maybe 3) of the icebreakers required to stock all outposts on the antartic continent. Exactly why were 4 journalists on this mission? 

 

surely this will go down as one of the greatest PR  disaster/exercises since the canoe trip to the Arctic a few years back.

 

 

Oh and by the way  -  VERY GOOD LUCK tomorrow.

 

MIA

[knocker]

Anyone care to comment?

 

Well I think this discussion is in danger of going around for the third time. Just to add I find the fact that Antarctic sea ice area has been extending since the satellite era and has been noted by BAS and all the other Antarctic scientists. In that time SSts have been warming slightly. But that really is beside the point when none of these scientists, to my knowledge, have come up with the simplistic reason that it's down to cooling SSTs. It would be more logical to say it's down to the ozone hole partly disrupting atmospheric circulation and that may well be part of the reason.

 

And of interest.

 

Key scientific questions which must be answered to meet the objectives of the Antarctic Sea Ice Processes and Climate Program are:

• What are the broad-scale time-varying distributions of the ice and snow-cover thickness, ice composition and other physical characteristics in the Antarctic sea ice zone?
• What are the dominant processes of ice formation, modification, decay and transport which influence and determine ice-thickness, composition and distribution?
• What is the role of coastal polynyas in determining total ice production, heat, salt and biogeochemical fluxes, and water mass modification?
• What are the processes that control the ice-water interactions at the ice-edge, and their seasonal changes?

Edited January 6, 2014 by knocker

[knocker]

It crossed my mind that these might be informative without need to enter into any fancy rhetoric and mud slinging.

 

About Sea Ice

 

What is Sea Ice?

 

Each winter the surface of a large area of the Southern Ocean freezes, forming a sea ice cover that surrounds Antarctica. This ice, with its expansive maximum extent and large annual variability has a major influence on the global climate system. A cover of sea ice affects the interaction between the ocean and the atmosphere by drastically modifying the transfer of heat, mass and momentum. This in turn impacts on the circulation of both the atmosphere and ocean.

 

The ice acts as a physical barrier to the exchange of gases (such as oxygen, carbon dioxide and water vapour), and as an insulating blanket between the relatively warm ocean and colder atmosphere. During winter when the temperature gradients between the surface ocean (whose temperature never falls below -1.9°C) and the atmosphere are greatest, the loss of heat to the atmosphere can be up to two orders of magnitude smaller over a sea ice cover than open ocean. With its high albedo (the fraction of incident solar radiation that is reflected by the surface) the ice and its snow cover also reduces the amount of incoming solar radiation absorbed at the ocean surface by reflecting much of it back to space. The transfer of momentum from the atmosphere to the ocean, which influences ocean currents, is also modified by the presence of ice. Sea ice is considerably less salty than sea water, and salt rejected from the ice structure during its formation and growth increases the salinity and density of the underlying water. This may induce deep vertical convection that contributes to the upwelling of nutrients and to the overall thermohaline circulation (water movement driven by salinity and temperature gradients) of the ocean. Conversely when the ice melts in spring it releases fresher water, forming a stable low salinity surface layer.

 

The Antarctic sea ice zone is a habitat for many species of biota. Many algal communities reside within or under the ice, and algal blooms occur in the stable freshwater "lens" that forms as the ice edge retreats in the summer. Large quantities of krill feed on the phytoplankton that in some way depend on the sea ice, and in turn provide a major food source for larger animals such as whales, seals and penguins. The sea ice is also used as a breeding platform by some seals and penguins, and may provide a refuge from predators.

 

Even in winter only a small fraction of sea ice close to the Antarctic continent occurs as a continuous and uniform sheet. This ice, called "land fast" ice, is pinned to the coast and does not move. The majority of the ice occurs in a wide band around the continent and is referred to as "pack ice". This is a region of highly variable ice conditions, including broken pieces (floes) with a range of sizes, ages and thicknesses, present in varying concentrations. The pack is highly mobile, moving with the wind and currents, with its characteristics constantly changing. There is frequently some open water (leads) between the floes and it is common to see ice at various stages of development present in the same area. This is the result of the dynamic nature of the pack, with the thickness of floes increasing through rafting and ridging as they interact, and new open water areas constantly being created allowing new ice to form.

 

The degree to which sea ice affects ocean-atmosphere interactions depends on the ice extent and its thickness distribution. The thickness distribution describes the nature of the surface within the pack in terms of the concentration (the fraction of surface area covered) of different ice thickness categories. While sea ice influences the ocean and the atmosphere, the distribution and characteristics of the ice are, in turn, forced by atmospheric and oceanic variables such as temperature, wind, ocean currents, and swell. Thus the ocean, sea ice and atmosphere form a complex interactive system.

 

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

 

Antarctic Sea Ice and Climate

 

Overview

 

The Antarctic sea ice zone remains one of the least known regions of the earth's surface. Apart from satellite derived data on ice extent and concentration, there are few reasonable climatological estimates of ice conditions that can be used for validation of numerical models. What limited information we have, mostly from the Weddell Sea, indicates that the ice characteristics and the dominant processes in the Antarctic are substantially different from those in the central Arctic. The Antarctic sea ice zone acts as a regional boundary between the Antarctic and sub Antarctic, an interface between the upper ocean and the lower atmosphere, and globally, as a region of important interactive physical and biogeochemical processes.

 

Uncertainties in, and the importance of, the role of sea ice in the climate system are highlighted in a US Global Change Program Report, Forum on Global Change Modeling. On the basis of studies of past climates, which provide evidence for polar amplification of warming it is predicted that under any future global warming scenario, Northern Hemisphere sea ice will probably be reduced, but that projected changes and their timing in the Southern Hemisphere sea ice extent are less certain. Current coupled model studies of an increased carbon dioxide atmosphere are also essentially in conflict in their predicted Southern Hemisphere sea ice response. First simulations with a coupled model even suggested an expansion, but more likely thickening, of the ice cover in particular regions. Other model studies, using different parameterisations of both fluxes and sea ice processes suggest the opposite effect; that instead sea ice extent and thickness will both be drastically reduced in increased atmospheric carbon dioxide scenarios. Through ice-albedo feedback, these latter simulations also suggest that the sea ice retreat itself accounts for a significant fraction (40%) of the global atmospheric warming that will occur under CO2 doubling, with of course very large increases in the regions more local to the present day ice cover. These projected changes are at present currently impossible to ascertain, because without knowledge of the Antarctic sea ice thickness distribution, it is difficult to provide compelling evidence if and when change occurs. Since the models currently give contradictory results, it suggests that the model parameterisations of sea ice physical processes are different and some, perhaps all, of the models are unrepresentative in some way in their depiction of the sea ice cover. Without present-day knowledge of the ice thickness distribution, models however cannot be verified, so we cannot even ascertain which model physics, if any, are correct.

 

The role of sea ice in the global climate system has been long recognised and included as a study component of major international weather and climate programs such as the Polar Sub-Programme of the Global Atmospheric Research Programme, and the World Climate Research Programme. However several factors have restricted implementation of a co-ordinated Antarctic sea ice zone program before the present. Many of the SCAR countries, tied also through the closely associated Council of Managers of National Antarctic Programmes (COMNAP), are already carrying out, and plan to continue, sea ice zone research in both physical and biological sciences within National programs: substantial new information is now available, particularly from the Weddell Sea, Amundsen and Bellingshausen Seas, and the Indian Ocean sector. A number of sophisticated, ice-capable research vessels are now working in the Antarctic, and at the same time the increased number of nations working in the Antarctic has seen a growth in all types of shipping activity. And new remote sensing capabilities, particularly active radar systems, have greatly enhanced sea ice observation from space.

 

http://aspect.antarctica.gov.au/home

Edited January 7, 2014 by knocker

[oldsnowywizard]

ok so back to the current ice state, anyone like to post some nice balanced views? according to CT we have 1.4mil extra ice extent... im sure the source of which is a mixture of glacial fall off and sea ice... im sure both happen every year and im also sure that in the past massive chunks of glacier have fallen off Antartica (GW or BFTV any nice data showing the top glacial chop offs by year?) anyway with the refreeze not too far away i wonder what the impacts will be? will everything melt beforehand? will the extent increase so much that they can see the ice from the falklands or australia? who knows but interesting for sure to see such a high anomaly so late in the season? 

[Tasboy]

Hello. I'm new here.

 

I have recently updated the SSTa maps around Antarctica to something that is a little more presentable.

They are here:

http://www.cawcr.gov.au/staff/preid/sst/reynolds_antarctic.html

 

There is a slight change in this analysis as to what was shown until recently. The old shaded grey area (previously representing sea ice) has been replaced with monthly average GSFC near-real-time sea ice concentration data. And the anomalies of SST are now based on the 1981-2010 climatology (where previously they were based on 1971-2000). Is it just me or are the decades slipping by very quickly?

 

Anyway, these might help you in your discussion.

Thanks,

Tasboy

[knocker]

Appreciate that Tasboy and welcome to the madhouse.

[Gray-Wolf]

Hi Tasbot!

 

Thanks for the new data...... difficult to take it all in this time of year with melt in full flow!

 

Hi OSW!

 

I know you're pulling legs about ice extension out to Ozz but some folk might take it more serious so I'd better mention the Circumpolar winds/current and the way that they effectively 'ring fence' the ice around the southern continent. Beyond this barrier we see the full range of temperatures and incredible storms that would make short work of and ice drifted out that far ( apart from the Mega Bergs! we know you can watch these floating by South island ,NZ or into the Berg Graveyard south of South Georgia!) You'd need to imagine the type of seas some of our recent storms have driven in the mid Atlantic ( both wave height and mixing) and how you would see ice possibly surviving such conditions.

 

As for re-freeze? i am beginning to think that we might be seeing global conditions in flux after over a decade of more settled forcings? We recently found just how much El Nina conditions impact the Pine Island complex so any move toward a more Nino dominated phase might see area of the continent react with increased melt rates?

 

As with the rest of the planet Antarctica is in 'a different place' than it was the last time we saw sea ice retreating ( late 70's?) and so it might be difficult to predict just how a resumption would react? With the loss of the larsen shelfs could Weddell be at risk of seeing it's ice become seasonal? ( it's like a mini Arctic to me protected by the peninsula and so able to retain ice year round...apart from the polynia) would an earlier retreat in Ross Sea impact the shelf there ( and 'my crack', that huge fissure running half the length of the shelf and dwarfing the 87' calve?).

 

As it is we are into the period where any major calves tend to occur as the 'girdle' of sea ice retreats and allows ocean processes to impact the coasts.

[knocker]

And on the subject of fairness.

 

This was no Antarctic pleasure cruise

 

After his polar vessel became trapped in shifting sea ice, Chris Turney defends the scientific basis of the expedition.

 

http://www.nature.com/news/this-was-no-antarctic-pleasure-cruise-1.14466

Edited January 10, 2014 by knocker

[jonboy]

 

And on the subject of fairness.

 

This was no Antarctic pleasure cruise

 

After his polar vessel became trapped in shifting sea ice, Chris Turney defends the scientific basis of the expedition.

 

http://www.nature.com/news/this-was-no-antarctic-pleasure-cruise-1.14466

 

 

Agreed it was no pleasure cruise but it wasn't unbiased science either. Lets not forget Chris Turner has set up two Carbon capture companies and I'm sure any findings would have clearly shown the need for reducing carbon hence my suspiscion of the motives involved

[knocker]

 Lets not forget Chris Turner has set up two Carbon capture companies and I'm sure any findings would have clearly shown the need for reducing carbon hence my suspiscion of the motives involved

 

Here we go again. That is pure speculation which I was hoping for once to avoid. And in an earlier post I listed the scientific aims and they were quite varied.

 

We are going south to:

• gain new insights into the circulation of the Southern Ocean and its impact on the global carbon cycle
• explore changes in ocean circulation caused by the growth of extensive fast ice and its impact on life in Commonwealth Bay
• use the subantarctic islands as thermometers of climatic change by using trees, peats and lakes to explore the past
• investigate the impact of changing climate on the ecology of the subantarctic islands
• discover the environmental influence on seabird populations across the Southern Ocean and in Commonwealth Bay
• understand changes in seal populations and their feeding patterns in the Southern Ocean and Commonwealth Bay
• produce the first underwater surveys of life in the subantarctic islands and Commonwealth Bay
• determine the extent to which human activity and pollution has directly impacted on this remote region of Antarctica
• provide baseline data to improve the next generation of atmospheric, oceanic and ice sheet models to improve predictions for the future

All our science work has been approved by the New Zealand Department of Conservation, the Tasmanian Parks and Wildlife Service and the Australian Antarctic Division. We are incredibly grateful for all their help and support.

 

And just for the record, irrespective of my stance on AGW, reducing our carbon emissions can only be a good policy.

Edited January 10, 2014 by knocker

[Gray-Wolf]

http://www.the-cryosphere-discuss.net/8/273/2014/tcd-8-273-2014.html

 

 

So no increase in Antarctic sea ice! (well either none or the measurement was incorrect before the 07' period and we need to look again at papers using that data).

 

If I'm reading too much into the paper then just ignore me but it does appear that the most sensible way around is no increase due to the anomalous nature of the increases over the period?

Edited January 14, 2014 by Gray-Wolf