From the NATIONAL CENTER FOR ATMOSPHERIC RESEARCH/UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH
BOULDER — The recent trend of increasing Antarctic sea ice extent — seemingly at odds with climate model projections — can largely be explained by a natural climate fluctuation, according to a new study led by the National Center for Atmospheric Research (NCAR).
The study offers evidence that the negative phase of the Interdecadal Pacific Oscillation (IPO), which is characterized by cooler-than-average sea surface temperatures in the tropical eastern Pacific, has created favorable conditions for additional Antarctic sea ice growth since 2000.
The findings, published in the journal Nature Geoscience, may resolve a longstanding mystery: Why is Antarctic sea ice expanding when climate change is causing the world to warm?
The study’s authors also suggest that sea ice may begin to shrink as the IPO switches to a positive phase.
“The climate we experience during any given decade is some combination of naturally occurring variability and the planet’s response to increasing greenhouse gases,” said NCAR scientist Gerald Meehl, lead author of the study. “It’s never all one or the other, but the combination, that is important to understand.”
Study co-authors include Julie Arblaster of NCAR and Monash University in Australia, Cecilia Bitz of the University of Washington, Christine Chung of the Australian Bureau of Meteorology, and NCAR scientist Haiyan Teng. The study was funded by the U.S. Department of Energy and by the National Science Foundation, which sponsors NCAR.
Expanding ice
The sea ice surrounding Antarctica has been slowly increasing in area since the satellite record began in 1979. But the rate of increase rose nearly five fold between 2000 and 2014, following the IPO transition to a negative phase in 1999.
The new study finds that when the IPO changes phase, from positive to negative or vice versa, it touches off a chain reaction of climate impacts that may ultimately affect sea ice formation at the bottom of the world.
When the IPO transitions to a negative phase, the sea surface temperatures in the tropical eastern Pacific become somewhat cooler than average when measured over a decade or two. These sea surface temperatures, in turn, change tropical precipitation, which drives large-scale changes to the winds that extend all the way down to Antarctica.
The ultimate impact is a deepening of a low-pressure system off the coast of Antarctica known as the Amundsen Sea Low. Winds generated on the western flank of this system blow sea ice northward, away from Antarctica, helping to enlarge the extent of sea ice coverage.
“Compared to the Arctic, global warming causes only weak Antarctic sea ice loss, which is why the IPO can have such a striking effect in the Antarctic,” said Bitz. “There is no comparable natural variability in the Arctic that competes with global warming.”
Sifting through simulations
To test if these IPO-related impacts were sufficient to cause the growth in sea ice extent observed between 2000 and 2014, the scientists first examined 262 climate simulations created by different modeling groups from around the world.
When all of those simulations are averaged, the natural variability cancels itself out. For example, simulations with a positive IPO offset those with a negative IPO. What remains is the expected impact of human-caused climate change: a decline in Antarctic sea ice extent.
But for this study, the scientists were not interested in the average. Instead, they wanted to find individual members that correctly characterized the natural variability between 2000-2014, including the negative phase of the IPO. The team discovered 10 simulations that met the criteria, and all of them showed an increase in Antarctic sea ice extent across all seasons.
“When all the models are taken together, the natural variability is averaged out, leaving only the shrinking sea ice caused by global warming,” Arblaster said. “But the model simulations that happen to sync up with the observed natural variability capture the expansion of the sea ice area. And we were able to trace these changes to the equatorial eastern Pacific in our model experiments.”
Scientists suspect that in 2014, the IPO began to change from negative to positive. That would indicate an upcoming period of warmer eastern Pacific Ocean surface temperatures on average, though year-to-year temperatures may go up or down, depending on El Niño/La Niña conditions. Accordingly, the trend of increasing Antarctic sea ice extent may also change in response.
“As the IPO transitions to positive, the increase of Antarctic sea ice extent should slow and perhaps start to show signs of retreat when averaged over the next 10 years or so,” Meehl said.
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The reality is not only has Antarctic Sea Ice been mostly above normal but in addition and even more telling the Southern Ocean temperatures have been below normal year in and year out. In addition the continent of Antarctica has shown nor warming which is just another nail into AGW theory.
This article does nothing to alter those realities.
Map will follow.
http://www.ospo.noaa.gov/data/sst/anomaly/2016/anomnight.7.4.2016.gif
I challenge them to explain this?
https://en.wikipedia.org/wiki/Polar_see-saw
Polar see-saw
Nothing one of Russia’s 47 ice breakers couldn’t solve.
https://m.youtube.com/watch?v=Q6OHHGrVM3g
When did this voyage take place?
These “scientists.” Reminds me of that quote about lawyers:
“To hear the word ‘truth’ on the lips of a lawyer is like hearing a prostitute say the word ‘love’.”
At some point, these people have to go home and face their families. Their careers are based on lies, and they live in fear of the truth. I wouldn’t want to be them. They are not much better than courtiers in the time of Rome. Please the current Emperor, but know that he will someday be gone and you will have a new master.
One of the founding myths of the global warming religion is that we understand the climate system so well we can accurately model it. (I did not make that up. That is what they used to say.) All deviations from the model are man-made, and harmful. Yet, despite this, new things keep being discovered about the climate system.
Just odd, that.
Bad natural variability trying to mask global warming :
“Compared to the Arctic, global warming causes only weak Antarctic sea ice loss, which is why the IPO can have such a striking effect in the Antarctic,” said Bitz. “There is no comparable natural variability in the Arctic that competes with global warming.”
But there’s always ‘another next 10 years’ we shall overcome :
“As the IPO transitions to positive, the increase of Antarctic sea ice extent should slow and perhaps start to show signs of retreat when averaged over the next 10 years or so,” Meehl said.
I guess the AMO is just a conspiracy theory.
Any ocean currents, atmospheric currents, and so forth depend heavily on being heat engines. That is true in both hemispheres. The AMO is one such heat engine.
The biggest problem is that these “scientists” have the memory span of a gnat and have not studied history. The population doubled during the Medieval Warming period in Europe from ~75MM to ~150MM. This was reduced by ~10% during the climate change of the early 14th century. http://academic.mu.edu/meissnerd/4horses.htm The plague during the mid 14th century reduced it by a further ~50%. Famines continued after that, even with a reduced population.
Bad natural variability. United we stand by global warming.
When the 262 models are averaged out, what does natural variability being canceled out actually mean in the physical world. If it rains on Monday and dry on Tuesday does the dry day on Tuesday cancel out the rain on Monday? And what does -expected human impact remains- mean when the the real Antarctic (you know the one not in the models) does not line up with the models? These guys are so disconnected from the physical world it is alarming, like kids hooked on video games who have no idea how to go outside and play.
Anyways I think they are saying that the average of the models do not reflect expanding antarctic ice, but they discovered (wow impressive, they “discovered” models that matches the physical world) 10 that actually line up with the physical world. Whoopee, cause for celebration, 3.8% of the models got acceptable results. I would suspend the celebration though, simply because a few models got the right answer does not mean they are a valid. After all random number generator might able to beat the 3.8% success rate.
http://www.nature.com/nature/journal/v457/n7233/full/4571093a.html
Climate change: Southern see-saw seen
Jeffrey P. Severinghaus1
Abstract
The bipolar see-saw hypothesis provides an explanation for why temperature shifts in the two hemispheres were out of phase at certain times. The hypothesis has now passed a test of one of its predictions.
http://www.nature.com/nature/journal/v457/n7233/edsumm/e090226-02.html
Editor’s Summary
26 February 2009
The north–south climate seesaw
Theoretical models and observational data have long suggested that the Northern and Southern Hemisphere climates behave in a seesaw-like fashion: when the northern ocean warms, the southern ocean cools and vice versa…
An analysis of new records from an ocean core from the South Atlantic — including planktonic foraminifera assemblages, Mg/Ca ratios, temperature and ocean productivity data — shows that the South Atlantic cooled essentially instantaneously with the warming in the North Atlantic during the last deglaciation. This first concrete evidence of an immediate seesaw connection also provides a link between the rapid warming in the North Atlantic and the more gradual Antarctic response, and suggests a mechanism potentially driving rapid Northern Hemisphere deglaciation.
so if this mechanism can drive deglaciation, why can it not drive climate change?
Since when did the Scientific method involve testing your hypothesis only against computer models?
Ceclia Bitz said: “There is no comparable natural variability in the Arctic that competes with global warming.”
?w=1000
Russian scientists at AARI disagree:
https://rclutz.wordpress.com/2015/12/23/arctic-sea-ice-self-oscillating-system/
Modellers calling themselves scientists and cooling is just natural variation while warming is anthropogenic. These guys just can’t help themselves. Plus, the usual “should” and “perhaps” about what may happen. When these guys make a hard core useful prediction and promise to eat their hats if they are wrong then I will show them at least some respect. At this point in time they deserve no respect.
The IPO (aka PDO) usually bounces to positive mode when we have an El Nino. Their interpretation is based on what they hope to see and has nothing to do with science. It already looks like it is switching back to negative with the onset of La Nina.
They are going to be so disappointed when the Arctic sea ice expands even more as the AMO declines. Darn that natural variability.
“There is no comparable natural variability in the Arctic that competes with global warming.”
===============
so what caused mile high ice over most of North America if not natural variability?
And then melted it all. Then re-froze it, at least four or five times.
Natural Variability must be funded by fossil fuel industry
“so what caused mile high ice over most of North America if not natural variability?”
===============
Luck
I find it refreshing to find that nature had at least something to do with one aspect of climate, and not mankind.
Cooling is natural, warming is man made.
Remember this and you will do fine in climatology.
We will see the argument that cooling is caused by warming caused by man. You see, politicians will strategically underfund snow clearing capability. Makes perfect sense heading for a future where snowfall is a very rare and exciting event. Swedish railways scrapped a large number of plow engines, and sure enough we had the coldest winter in over 100 years. So they had to spin it as an unforseen effect of global warming.
“The recent trend of increasing Antarctic sea ice extent — seemingly at odds with climate model projections — can largely be explained by a natural climate fluctuation, …”
“Natural climate fluctuation”!!!
Wow, wonder when that started happening?
Now that such a thing has been identified, maybe the “climate scientists” could incorporate it into their thinking?
Or is it something only “climate skeptics” do?
/sarc /cynic
Let’s walk this through.
The authors found 10 GCMs that yielded an explanation for the growth of southern sea ice. A positive number.
When they took the average of those ten positive numbers it revealed the underlying AGW loss of sea ice. A negative number.
Don’t try this at home or on your tax returns ladies and gentlemen.
I do however thank the authors for demonstrating that only 10 of 262 climate simulations came even close. Far less than 262 random generators might be expected to pass I might add.
…But do those 10 models get the Arctic right ? I am sure, out of 262 models, most of them probably get one small area right and all the rest wrong ! Not very useful….
Always remember the 97%-number…….science is a majority process, 252 simulations must be right,
they are the 97% of science…. the outliers, the remaining 10 studies have the actual numbers right, but
this does not count as science. We therefore have to eliminate those 10 right number studies from
the record and stay with the scientific majority, which simulate otherwise…….
Love that “natural variability” almost as much as we blame Man. Saves our faith without any inconvenient questions about our holy models. All hail Gaia!/sarc
In a nutshell: if the ice is expanding it’s natural, if the ice is shrinking it’s man-made.
More squawking about squiggles.
“The recent trend of increasing Antarctic sea ice extent — seemingly at odds with climate model projections — can largely be explained by a natural climate fluctuation.”
They have this backwards. They need to explain why the models do not agree with the real sea ice extent. The models are failing, not the Antarctic.
This sounds just like a past statement by some talking head, defending the models, who said that the Earth had failed to warm as predicted. No, the models failed to predict what the planet would really do.
Computer models of climate are NOT science and should not be treated as so.
…You are failing to understand…Liberals don’t live in the real world !…All their talking points are fantasy developed in a Utopian mind !
10 out of 262 simulations hit the object. It would be interesting to see which models that can be trusted to say something of the ocean currents that can fit observations. Is it one model, or is it 5 models?
Me, 2…
They have a grab bag of excuses for why their precious models have failed; natural variation being the one they happened to pull out this time. Each time they pull one out, they act like it’s “new”, and act all surprised. But they steadfastly forge ahead, firm in their Belief that manmade warming is still there. It just has to. Their paychecks depend on it.