Stronger winds explain puzzling growth of sea ice in Antarctica

Sep 18, 2013 by Hannah Hickey
This mixture of different types of Antarctic sea ice was photographed Oct. 13, 2012, by a NASA aircraft flying over the Bellingshausen Sea. Credit: NASA/Digital Mapping System

(Phys.org) —Much attention is paid to melting sea ice in the Arctic. But less clear is the situation on the other side of the planet. Despite warmer air and oceans, there's more sea ice in Antarctica now than in the 1970s – a fact often pounced on by global warming skeptics. The latest numbers suggest the Antarctic sea ice may be heading toward a record high this year.

A University of Washington researcher says the reason may lie in the winds. A new modeling study to be published in the Journal of Climate shows that stronger polar winds lead to an increase in Antarctic , even in a warming climate.

"The is that the Southern Ocean is warming," said author Jinlun Zhang, an at the UW Applied Physics Laboratory. "Why would sea ice be increasing? Although the rate of increase is small, it is a puzzle to scientists."

His new study shows that stronger swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.

The that swirls around the South Pole is not just stronger than it was when began in the 1970s, it has more convergence, meaning it shoves the sea ice together to cause ridging. Stronger winds also drive ice faster, which leads to still more deformation and ridging. This creates thicker, longer-lasting ice, while exposing surrounding water and thin ice to the blistering cold winds that cause more ice growth.

In a computer simulation that includes detailed interactions between wind and sea, thick ice—more than 6 feet deep—increased by about 1 percent per year from 1979 to 2010, while the amount of thin ice stayed fairly constant. The end result is a thicker, slightly larger ice pack that lasts longer into the summer.

Stronger winds explain puzzling growth of sea ice in Antarctica
Antarctic sea ice concentration changes from 1981 to 2011. Credit: U.S. National Snow and Ice Data Center

"You've got more thick ice, more ridged ice, and at the same time you will get more ice extent because the ice just survives longer," Zhang said.

When the model held the polar winds at a constant level, the sea ice increased only 20 percent as much. A previous study by Zhang showed that changes in water density could explain the remaining increase.

"People have been talking about the possible link between winds and Antarctic sea ice expansion before, but I think this is the first study that confirms this link through a model experiment," commented Axel Schweiger, a polar scientist at the UW Applied Physics Lab. "This is another process by which dynamic changes in the atmosphere can make changes in sea ice that are not necessarily expected."

The research was funded by the National Science Foundation.

Still unknown is why the southern winds have been getting stronger. Some scientists have theorized that it could be related to global warming, or to the ozone depletion in the Southern Hemisphere, or just to natural cycles of variability.

Differences between the two poles could explain why they are not behaving in the same way. Surface air warming in the Arctic appears to be greater and more uniform, Zhang said. Another difference is that northern water is in a fairly protected basin, while the Antarctic sea ice floats in open oceans where it expands freely in winter and melts almost completely in summer.

In mid-September, Antarctic sea ice extent is near the satellite-era record high that was set last year. Credit: Univ. of Bremen/AMSR2

The sea ice uptick in Antarctica is small compared with the amount being lost in the Arctic, meaning there is an overall decrease in sea ice worldwide.

Many of the global climate models have been unable to explain the observed increase in Antarctic sea ice. Researchers have been working to improve models to better reproduce the observed increase in sea ice there and predict what the future may bring.

Eventually, Zhang anticipates that if warmer temperatures come to dominate they will resolve the apparent contradiction.

"If the warming continues, at some point the trend will reverse," Zhang said.

Explore further: Arctic ice shrinking in volume, too, ESA reports

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ubavontuba
1.6 / 5 (26) Sep 18, 2013
Stronger winds also drive ice faster, which leads to still more deformation and ridging. This creates thicker, longer-lasting ice, while exposing surrounding water and thin ice to the blistering cold winds that cause more ice growth.
Right, 'cause we all know ice forms better in choppy water (sarcasm).

Then we have this little gem:

Although the rate of increase is small, it is a puzzle to scientists."


...followed by this:

His new study shows that stronger westerly winds swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.


I don't know about anyone else, but I think an 80% increase in most anything this large (millions of square miles) can hardly be described as small!

barakn
4.3 / 5 (16) Sep 18, 2013
Only you would be so stupid as to confuse the phrase "80 percent of the increase" to mean "80% increase."
Jim Steele
1.2 / 5 (19) Sep 18, 2013
The model seems to make some odd speculations. Most of the Antarctic sea ice is driven by the katabaitc winds blowng from the continental interior. Unconstrained by other continents, most of the Antarctcc sea ice expands with much less ridging than witnessed in the Arctic. For that reason most of Antarctic's sea ice is first year. In contrast, the Arctic Oscillation causes cycles of more ridging and thicker ice alternating with periods of when that thick ice is blown into the Atlantic. Furthermore the sectors where ice is growing has not experienced warming.
ubavontuba
1.6 / 5 (23) Sep 18, 2013
Only you would be so stupid as to confuse the phrase "80 percent of the increase" to mean "80% increase."
You are correct, I misread it.

According to this site, it looks like the correct figures for this year are: Antarctic Minimum (summer ice) was up 86.9% (1.12686 million sq. km) and the current near maximum/maximum (winter ice) is up 12.1% (1.69256 million sq. km).

Neither of which are "small" increases.

triplehelix
1.4 / 5 (21) Sep 19, 2013
Their best models could only gain 20% increase, rather than the actual increase observed.

When the model held the polar winds at a constant level, the sea ice increased only 20 percent as much. A previous study by Zhang showed that changes in water density could explain the remaining increase.


And yet the models are "An excellent tool that get very close approximates"...

Right. Sure.

The real slap of the knee laugh however is how they try to save face by referencing a study where water viscosity "could" (not does/can) explain the ice increase.

Two issues here.

1. Why the hell does an antarctic sea ice model not have water density as one of it's working variables? LOL.

2. Even I don't think these people are stupid enough to not account for water density in their models, in which case they're applying change of density twice if using the two studies to "tot up the figures" as us brits say.

What a joke.

It's getting warmer because they removed many buoys over the years
triplehelix
1.4 / 5 (22) Sep 19, 2013
It's a well documented fact that the temperature readings across the globe are biased, with many cooler ones being got rid of, or not being used in the datasets, and some sensors being placed over asphalt etc which give off tons of heat. You can literally find pictures everywhere of these monitoring stations and their position failings. Most of siberias and alaskas stations have been completely removed from the models and dataset results. No wonder it's getting warmer.
runrig
4.3 / 5 (11) Sep 19, 2013
It's a well documented fact that the temperature readings across the globe are biased, with many cooler ones being got rid of, or not being used in the datasets, and some sensors being placed over asphalt etc which give off tons of heat. You can literally find pictures everywhere of these monitoring stations and their position failings. Most of siberias and alaskas stations have been completely removed from the models and dataset results. No wonder it's getting warmer.


From the Berkeley (BEST) study - by former skeptic Muller (Et Al) and financed by the Kochs (Heartland Foundation)

"Berkeley Earth also has carefully studied issues raised by skeptics, such as possible biases from urban heating, data selection, poor station quality, and data adjustment. We have demonstrated that these do not unduly bias the results."

http://berkeleyea...summary/

cont
runrig
4.2 / 5 (10) Sep 19, 2013
cont
Wiki:
"The preliminary results of an independent assessment carried out by the Berkeley Earth Surface Temperature group, and made available to the public in October 2011, found that among other scientific concerns raised by skeptics, the urban heat island effect did not bias the results obtained by NOAA, the Hadley Centre and NASA's GISS. The Berkeley Earth group also confirmed that over the past 50 years the land surface warmed by 0.911°C, and their results closely matched those obtained from earlier studies"

Several independent studies have confirmed no warm bias by the removal of stations.
Linked to here....
http://www.skepti...bias.htm

Also, can I point out that in a warming world places furthest towards the Poles will experience a greater degree of warming. I do believe that Alaska and Siberia come into that category.

The conspiracists have shot themselves in the foot eh?

And if a skeptic can't substantiate your assertion?
VendicarE
3.5 / 5 (11) Sep 19, 2013
"but I think an 80% increase in most anything this large " - UbVonTard

Chronic liar UbVonTard claims an 80 percent increase.

The reality is Antarctic ice extent is on the high side of the expected distribution.

http://arctic.atm...ive.html
VendicarE
3.5 / 5 (11) Sep 19, 2013
"It's a well documented fact that the temperature readings across the globe are biased, with many cooler ones being got rid of" - DumberThanDumb

I don't remember reading any such documentation in the scientific literature.

Perhaps you mean that it has been well documented in the denialist fantasy press.

Can you explain to us why when we add in the data sets that you falsely claim are missing, the global temperature averages go up, rather than down, as you claim?

You should stop eating other people's dung, TardieBoy.

It makes your breath stink.
VendicarE
3.5 / 5 (11) Sep 19, 2013
Only you would be so stupid as to confuse the phrase "80 percent of the increase" to mean "80% increase." - Barakn

Always remember that UbVonTard is paid to come here and Lie.

Lying is his reason for existence. It is his mode of existence.

Lying is his life.

Neal Asher
1.4 / 5 (22) Sep 23, 2013
"puzzling growth of sea ice in Antarctica" Never mind, I'm sure it's still shrinking catastrophically in the climate models.
thermodynamics
4 / 5 (8) Sep 23, 2013
Neal: You said:
"puzzling growth of sea ice in Antarctica" Never mind, I'm sure it's still shrinking catastrophically in the climate models.


Would you please give us a link to which model shows the Antarctic shrinking? It is a new aspect of the models I was not aware of. What I have seen is analyses of the ice that show it growing as the temperatures remain below freezing and air is slightly warmer and carries more water vapor. If the oceans warm (as they are measured to be) they put more water vapor into the atmosphere. That moisture laden air then drops below freezing and deposits snow and ice. You do realize that there are parts of inland Antarctica that have very low precipitation rates because it is too cold and the water vapor has deposited out before getting there. Again, I would love to see you link to the model results that show the ice to be "shrinking catastrophically."
ubavontuba
1.4 / 5 (20) Sep 23, 2013
Would you please give us a link to which model shows the Antarctic shrinking? It is a new aspect of the models I was not aware of. What I have seen is analyses of the ice that show it growing as the temperatures remain below freezing and air is slightly warmer and carries more water vapor. If the oceans warm (as they are measured to be) they put more water vapor into the atmosphere. That moisture laden air then drops below freezing and deposits snow and ice. You do realize that there are parts of inland Antarctica that have very low precipitation rates because it is too cold and the water vapor has deposited out before getting there. Again, I would love to see you link to the model results that show the ice to be "shrinking catastrophically."
This is too easy. Even the scientists are concerned about this and are rapidly trying to justify it as a result of AGW. LOL

http://www.thegwp...ecrease/

Maggnus
3.5 / 5 (11) Sep 23, 2013
His new study shows that stronger westerly winds swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.


I don't know about anyone else, but I think an 80% increase in most anything this large (millions of square miles) can hardly be described as small!



As usual, you don't seem able to read. It doesn't say there is an 80% increase, it says it EXPLAINS 80% OF the increase.
ubavontuba
1.4 / 5 (18) Sep 23, 2013
His new study shows that stronger westerly winds swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.
I don't know about anyone else, but I think an 80% increase in most anything this large (millions of square miles) can hardly be described as small!
As usual, you don't seem able to read. It doesn't say there is an 80% increase, it says it EXPLAINS 80% OF the increase.
You need to read further...
Neinsense99
2 / 5 (16) Sep 29, 2013
His new study shows that stronger westerly winds swirling around the South Pole can explain 80 percent of the increase in Antarctic sea ice volume in the past three decades.
I don't know about anyone else, but I think an 80% increase in most anything this large (millions of square miles) can hardly be described as small!
As usual, you don't seem able to read. It doesn't say there is an 80% increase, it says it EXPLAINS 80% OF the increase.
You need to read further...

Yes, read further, into the realm of self-serving fantasy, where drifting @$$ smoke explains how what was not written is really what was written, even if it doesn't match what is in the text.
ubavontuba
1.5 / 5 (16) Sep 29, 2013
You need to read further...
Yes, read further, into the realm of self-serving fantasy, where drifting @$$ smoke explains how what was not written is really what was written, even if it doesn't match what is in the text.
You appear to have a problem with reading comprehension...
Jim Steele
1.3 / 5 (16) Oct 01, 2013
At runrig The Best methodology homogenizes the data based on subjective decisions about the lack of data homogeneity, and assume the lack of homogeneity means "undocumented" changes to the weather station (i.e. location or instrumentation) and then they adjust the data to fabricate a trend. I have documented instances where this is a big mistake, biases the trend and obliterates the effects of natural cycles like the Pacific Decadal Oscilation. http://landscapes...ts-.html
Neinsense99
2 / 5 (16) Oct 01, 2013
It's a well documented fact that the temperature readings across the globe are biased, with many cooler ones being got rid of, or not being used in the datasets, and some sensors being placed over asphalt etc which give off tons of heat. You can literally find pictures everywhere of these monitoring stations and their position failings. Most of siberias and alaskas stations have been completely removed from the models and dataset results. No wonder it's getting warmer.

Somebody is confusing repeatedly asserted with "well documented". They are not the same thing.
antigoracle
1.6 / 5 (14) Nov 08, 2013
The AGW Cult's survival is so contingent on propagating their CO2 lie, that they must dig an even deeper hole for themselves with even more preposterous fabrications, which they have the audacity to label "science"

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