New research shows projected changes in the winds circling the Antarctic may accelerate global sea level rise significantly more than previously estimated.
Changes to Antarctic winds have already been linked to southern Australia’s drying climate but now it appears they may also have a profound impact on warming ocean temperatures under the ice shelves along the coastline of West and East Antarctic.
“When we included projected Antarctic wind shifts in a detailed global ocean model, we found water up to 4°C warmer than current temperatures rose up to meet the base of the Antarctic ice shelves,” said lead author Dr Paul Spence from the ARC Centre of Excellence for Climate System Science (ARCCSS).
“The sub-surface warming revealed in this research is on average twice as large as previously estimated with almost all of coastal Antarctica affected. This relatively warm water provides a huge reservoir of melt potential right near the grounding lines of ice shelves around Antarctica. It could lead to a massive increase in the rate of ice sheet melt, with direct consequences for global sea level rise.”
Prior to this research by Dr Spence and colleagues from Australian National University and the University of New South Wales, most sea level rise studies focused on the rate of ice shelf melting due to the general warming of the ocean over large areas.
Using super computers at Australia’s National Computational Infrastructure (NCI) Facility the researchers were able to examine the impacts of changing winds on currents down to 700m around the coastline in greater detail than ever before.
Previous global models did not adequately capture these currents and the structure of water temperatures at these depths. Unexpectedly, this more detailed approach suggests changes in Antarctic coastal winds due to climate change and their impact on coastal currents could be even more important on melting of the ice shelves than the broader warming of the ocean.
“When we first saw the results it was quite a shock. It was one of the few cases where I hoped the science was wrong,” Dr Spence said.
“But the processes at play are quite simple, and well-resolved by the ocean model, so this has important implications for climate and sea-level projections. What is particularly concerning is how easy it is for climate change to increase the water temperatures beside Antarctic ice sheets.”
The research may help to explain a number of sudden and unexplained increases in global sea levels that occurred in the geological past.
“It is very plausible that the mechanism revealed by this research will push parts of the West Antarctic Ice Sheet beyond a point of no return,” said Dr Axel Timmerman, Prof of Oceanography at University of Hawaii and an IPCC lead author who has seen the paper.
“This work suggests the Antarctic ice sheets may be less stable to future climate change than previously assumed.”
Recent estimates suggest the West Antarctic Ice Sheet alone could contribute 3.3 metres to long-term global sea level rise.
With both West and East Antarctica affected by the change in currents, in the future abrupt rises in sea level become more likely.
According to another of the paper’s authors, Dr Nicolas Jourdain from ARCCSS, the mechanism that leads to rapid melting may be having an impact on the Western Antarctic right now. Dr Jourdain said it may help explain why the melt rate of some of the glaciers in that region are accelerating more than scientists expected.
“Our research indicates that as global warming continues, parts of East Antarctica will also be affected by these wind-induced changes in ocean currents and temperatures,” Dr Jourdain said.
“Dramatic rises in sea level are almost inevitable if we continue to emit greenhouse gases at the current rate.”
Abstract
The southern hemisphere westerly winds have been strengthening and shifting poleward since the 1950s. This wind trend is projected to persist under continued anthropogenic forcing, but the impact of the changing winds on Antarctic coastal heat distribution remains poorly understood. Here we show that a poleward wind shift at the latitudes of the Antarctic Peninsula can produce an intense warming of subsurface coastal waters that exceeds 2 °C at 200-700 m depth. The model simulated warming results from a rapid advective heat flux induced by weakened near-shore Ekman pumping, and is associated with weakened coastal currents. This analysis shows that anthropogenically induced wind changes can dramatically increase the temperature of ocean water at ice sheet grounding lines and at the base of floating ice shelves around Antarctica, with potentially significant ramifications for global sea level rise.
Changes to Antarctic winds have already been linked to southern Australia’s drying climate
===============
Thus Australia built a bunch of very expensive desalination plants. Based on Climate Science recommendations. Now mothballed, lying idle. And record flooding swept Queensland.
Antarctic ice excess at new record!! The size of Greenland!! It is getting colder.
Is this official data lying? Ice freezes when it is getting cold. There is no need for adjusting or homogenizing the data.
http://lenbilen.com/2014/07/03/antarctic-ice-excess-at-new-record-the-size-of-greenland-it-is-getting-colder/
The “anthropogenically induced wind changes” was a pretty bold assumption thrown in at the beginning of their modeling process. I would like to see evidence that the wind changes are even semi-permanent and are actually induced by man. I hate this type of “scientistic” speculation.
I just went to the NSIDC Page to check on the Arctic ice conditions. Whenever I have gone to their page, I have always seen both Arctic and Antarctic updates. Not this time, though. On the main “news” page where you find all the info, there is not one mention of Antarctic ice. (Except for one little link at the top showing a couple charts called “Antarctic Daily Image”. Is this normal?
The fortune telling bit is the same game, but the crystal ball looks more like a bank of computer servers. The price? Rising higher and higher. The con? Getting dirtier and dirtier.
We should expect more and more nonsense speculation like this about Antarctica since the sea ice around the continent continues to break records in extent. My respect for the “peer reviewed” paper continues to decline.
Negative feedbacks are not allowed in climate science.
IOW, the winds will only speed up if the global temperature rises. But if it doesn’t, as it hasn’t been, then they won’t–and the knock-on effect won’t happen either.
Could … might … may … suggests … modeled …
Yawn.
Anybody else bored with all of the “it’s worse than we thought” modeling?
News flash (or not) Antarctica has been melting for 15,000 years.
Call me when you have some real data.
Bill Illis says:
July 8, 2014 at 6:00 am
“Climate models do not trump real history.”
————————————————————————————————————————-
They can appear to if one is ignorant of history.
“When we first saw the results it was quite a shock. It was one of the few cases where I hoped the science was wrong,” Dr Spence said.
So in most other cases they are happy that disaster is on the way?
Waterproof super computers capable of descending to 700m. Imagine that.
What? They used the computers to model projected winds and currents, not actually observe them.
Oh. Never mind. Just more journalistic misrepresentation.
In reply to:
bernie1815 says:
July 8, 2014 at 5:47 am
And the continued growth of Antarctic sea ice is explained how?
William:
That is a tough question to answer. Here is an attempt.
Peer review analysis indicates, surprise, surprise, surprise, there is more sea ice in an Antarctic region when the surface air temperature in the Antarctic region in question is colder. Who would have thought that? Likely also applies to the Arctic.
http://www.aoml.noaa.gov/phod/docs/Shu_etal_2012.pdf
Sea ice trends in the Antarctic and their relationship to surface air temperature during 1979–2009
“…If the relationship between SIC and GISS SAT trends is examined regionally, Antarctic SIC trends agree well with the local SAT trends in the most Antarctic regions. That is, Antarctic SIC and SAT show an inverse relationship: a cooling (warming) SAT trend is associated with an upward (downward) SIC trend. It is also concluded that the relationship between sea ice and SAT trends in the Antarctic should be examined regionally rather than integrally.”
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
http://nsidc.org/data/seaice_index/images/daily_images/S_bm_extent_hires.png
So as it is a fact that sea ice is now more than two sigma higher for every month of the year in the Antarctic and the sea ice in question is found in all regions of the Antarctic, what is the logical conclusion?
Yep. It’s getting colder in the Antarctic.
The proxy data indicates it has warmed 342 times in the Antarctic in the last 240,00 years (1500 year and 400 year periodicity, same as the observed Dansgaard-Oeschger warming/cooling cycle in the Northern hemisphere). 342 times the warming period was followed by a cold period.
http://wattsupwiththat.com/2012/09/05/is-the-current-global-warming-a-natural-cycle/
http://wattsupwiththat.files.wordpress.com/2012/09/davis-and-taylor-wuwt-submission.pdf
The physical reason for the sudden high latitude cooling? An increase in low altitude clouds and a reduction in high altitude cirrus clouds (the wispy cirrus clouds warm by the greenhouse affect particularly in the winter, note there is record sea ice now in the Antarctic winter.). The change in Antarctic cloud cover is caused by a reduction in solar wind bursts (Ap which a measurement of changes to the geomagnetic field caused by solar wind bursts is down by 66% as compared to previous solar magnetic cycle maximums see link below.) and by an increase in galactic cosmic rays (GCR also called cosmic ray flux CRF, GCR/CRF is mostly high speed protons). The GCR/CRF (high speed protons) strike the atmosphere and create cloud forming ions. The solar wind bursts remove cloud forming ions by creating a space charge differential in the ionosphere which creates a potential differential between the poles of the planet and the equator. Solar magnetic cycle changes modulate GCR/CRF by what is called the solar heliosphere. The solar magnetic cycle creates what is called the solar heliosphere (a tenuous cloud of magnetic flux and gas ejected from the sun, that extends well past the orbit of Pluto). The solar heliosphere blocks and deflects a portion of the high speed protons (GCR/CRF).
http://hockeyschtick.blogspot.ca/2014/07/peak-solar-geomagnetic-activity-shows.html
Tom in Florida, if you think the Crazy World of Arthur Brown is a hoot, come down to Tasmania and try the loony green world of Bob Brown.
As for the supposed drying of southern Australia, actually it is only the SW of Western Australia that has dried off ( -20%) and Tasmania to a lesser extent (-10%) although the latter has twice the rainfall of the mainland to start with. Southern Ausytralia as a whole has got wetter by about 10% so go figure.
This ‘research’ is the latest offering from the Retard Twerk outfit that brought you the Ship of Fools debacle so you can imagine the sort of breathless eco conference junkies we are talking about.
Incidentally I am in Perth, WA as I type and if sure ain’t dry here at the moment!
What does it take to get a doctorate degree? Maybe a box of cracker jacks and wish that the world will end.
Another MODEL result.
The thing that shocked me was the fact that the increased 200 to 700 meter warmer water didn’t try to rise to the surface, and melt all that additional sea ice that has been increasing for the past 20 years.
“Here we show that a poleward wind shift at the latitudes of the Antarctic Peninsula can produce an intense warming of subsurface coastal waters that exceeds 2 °C at 200-700 m depth.”
‘And when we rigged the model we were shocked at the result’?
The funding vampires are always “shocked” at their results fabricated from computer simulations based on other model simulations of what the global temperatures may do to SSTs and winds and currents themselves based on models and simulations. A great big steaming pile of speculation supported by guesswork and wishful thinking. And none of it takes into account the now historic record sea ice levels. And where have we heard the old ‘its a supercomputer so it cant be wrong’ claim before?
The Antarctic sea ice is 100 – 200 kilometers from the Antarctic shore AT MINIMUM EXTENTS each Antarctic melting season in mid-February each year. During “average” Antarctic sea ice periods, the edge of the Antarctic sea ice from the continental ice and the two largest Antarctic Shelf Ice, that distance is 500 – 1200 kilometers away from the “disturbed” region where Antarctic circular winds could FIRST begin influencing sub-surface ocean currents. At maximum Antarctic sea ice between August and October each year, this distance is 1000 – 1500 kilometers away, some place even greater.
What distances from the Antarctic coast did these people use to create such increased ocean movements from wind? Even off of the US coast, the tremendous Gulf Stream is a narrow band of currents. What measurements have they cited to verify even the original current “model” – much less the CHANGES to the original Antarctic current flows AFTER increased Antarctic sea ice the past 7 years AND the potential Antarctic continued global warming. Which global warming, by satellite measurements – is actually NOT warming over Antarctica the past 50 years of satellite and regional air measurements!
Further problems with this propaganda: There are only a few places where the Antarctic “toe melting” can actually occur: in the tips of only three glaciers off of the West Antarctic sheets which “drain” only 5% of the Antarctic continental ice cap. Thus, only three glaciers are “fixed” by their toe grounding (the biggest are Thwaits and Pine Island Glaciers), and THAT movement can be better explained by a 2 meter INCREASE in glacier depth than by a recent melting under the toe of the glacier.
I read somewhere that at the current rate of ‘man made’ wind-change/antarctic melting/worse-than-we-thought b.s. that it will be 2200 before 1 % of said ice mass melts…..wow. Where is the data linking the trace chemical 95% emitted by Gaia to ‘wind’….love to see that ‘proof’.
Bill Illis
“Climate models do not trump real history”
I agree with you . This looks like another flawed alarmist attempt to push the sea level rise issue again . If winds are more active in the Antarctic, the opposite off setting could happen too,
More winds > more mixing and upwelling of cold water to Southern oceans and to ocean conveyor belts > cooler surface currents > cooling of southern and mid latitude Atlantic SST > > cooling of North Atlantic Ocean STT> more rain in Northern Hemisphere > less salinity in Northern Atlantic ocean> slowdown of ocean conveyor belt > more freezing of Arctic oceans .> more ice > less sea level rise
This paper is nothing more than speculation. We know little to nothing about sea surface temperatures in the Southern Ocean before the satellite era, and we have even fewer samples of subsurface temperatures for the Southern Ocean before 2003. We know nothing of the decadal, multidecadal and centennial variability of coupled ocean-atmosphere processes there, nothing.
The piece talks about a 2 degree rise in sea water temp due to the wind, , but i wonder if this is only during the summer months. If the summer winds can do this what can the winter winds do? From my experience the AGW crowd tends to leave out half the story.
The advantage of super computors is that they can digest a larger questionable Model and output more questionable data faster than a less than super computor can.
William: I cannot judge the validity of your account – but the increasing Antarctic sea ice seems to be a “fact”. But, to follow on Bob Tisdale’s trenchant comment, if the authors do not have the SST data, they do not have the data to even justify their theory. Their mode of scientific reasoning just leaves me baffled. It is like reading medieval theological treatises: Yes, it is possible but is it real?