Columbia engineering study links ozone hole to climate change all the way to the equator
First time that ozone depletion is shown to impact the entire circulation of the southern hemisphere
In a study to be published in the April 21st issue of Science magazine, researchers at Columbia University’s School of Engineering and Applied Science report their findings that the ozone hole, which is located over the South Pole, has affected the entire circulation of the Southern Hemisphere all the way to the equator. While previous work has shown that the ozone hole is changing the atmospheric flow in the high latitudes, the Columbia Engineering paper, “Impact of Polar Ozone Depletion on Subtropical Precipitation,” demonstrates that the ozone hole is able to influence the tropical circulation and increase rainfall at low latitudes in the Southern Hemisphere. This is the first time that ozone depletion, an upper atmospheric phenomenon confined to the polar regions, has been linked to climate change from the Pole to the equator.
“The ozone hole is not even mentioned in the summary for policymakers issued with the last IPCC report,” noted Lorenzo M. Polvani, Professor of Applied Mathematics and of Earth & Environmental Sciences, Senior Research Scientist at the Lamont-Doherty Earth Observatory, and co-author of the paper. “We show in this study that it has large and far-reaching impacts. The ozone hole is a big player in the climate system!”
“It’s really amazing that the ozone hole, located so high up in the atmosphere over Antarctica, can have an impact all the way to the tropics and affect rainfall there — it’s just like a domino effect,” said Sarah Kang, Postdoctoral Research Scientist in Columbia Engineering’s Department of Applied Physics and Applied Mathematics and lead author of the paper.
The ozone hole is now widely believed to have been the dominant agent of atmospheric circulation changes in the Southern Hemisphere in the last half century. This means, according to Polvani and Kang, that international agreements about mitigating climate change cannot be confined to dealing with carbon alone— ozone needs to be considered, too. “This could be a real game-changer,” Polvani added.
Located in the Earth’s stratosphere, just above the troposphere (which begins on Earth’s surface), the ozone layer absorbs most of the Sun’s harmful ultraviolet rays. Over the last half-century, widespread use of manmade compounds, especially household and commercial aerosols containing chlorofluorocarbons (CFCs), has significantly and rapidly broken down the ozone layer, to a point where a hole in the Antarctic ozone layer was discovered in the mid 1980s. Thanks to the 1989 Montreal Protocol, now signed by 196 countries, global CFC production has been phased out. As a result, scientists have observed over the past decade that ozone depletion has largely halted and they now expect it to fully reverse, and the ozone hole to close by midcentury.
But, as Polvani has said, “While the ozone hole has been considered as a solved problem, we’re now finding it has caused a great deal of the climate change that’s been observed.” So, even though CFCs are no longer being added to the atmosphere, and the ozone layer will recover in the coming decades, the closing of the ozone hole will have a considerable impact on climate. This shows that through international treaties such as the Montreal Protocol, which has been called the single most successful international agreement to date, human beings are able to make changes to the climate system.
Together with colleagues at the Canadian Centre for Climate Modelling and Analysis in Victoria, BC, Kang and Polvani used two different state-of-the-art climate models to show the ozone hole effect. They first calculated the atmospheric changes in the models produced by creating an ozone hole. They then compared these changes with the ones that have been observed in the last few decades: the close agreement between the models and the observations shows that ozone has likely been responsible for the observed changes in Southern Hemisphere.
This important new finding was made possible by the international collaboration of the Columbia University scientists with Canadian colleagues. Model results pertaining to rainfall are notoriously difficult to calculate with climate models, and a single model is usually not sufficient to establish credible results. By joining hands and comparing results from two independent models, the scientists obtained solid results.
Kang and Polvani plan next to study extreme precipitation events, which are associated with major floods, mudslides, etc. “We really want to know,” said Kang, “if and how the closing of the ozone hole will affect these.”
This study was funded by a grant from the National Science Foundation to Columbia University.
Columbia Engineering
Columbia University’s Fu Foundation School of Engineering and Applied Science, founded in 1864, offers programs in nine departments to both undergraduate and graduate students. With facilities specifically designed and equipped to meet the laboratory and research needs of faculty and students, Columbia Engineering is home to NSF-NIH funded centers in genomic science, molecular nanostructures, materials science, and energy, as well as one of the world’s leading programs in financial engineering. These interdisciplinary centers are leading the way in their respective fields while individual groups of engineers and scientists collaborate to solve some of society’s more vexing challenges. http://www.engineering.columbia.edu/
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Impact of Polar Ozone Depletion on Subtropical Precipitation
Kang et al 2011, Science Express
Abstract:
Over the past half-century, the ozone hole has caused a
poleward shift of the extratropical westerly jet in the
Southern Hemisphere. Here, we argue that these
extratropical circulation changes, resulting from ozone
depletion, have substantially contributed to subtropical
precipitation changes. Specifically, we show that
precipitation in the Southern subtropics in austral
summer increases significantly when climate models are
integrated with reduced polar ozone concentrations.
Furthermore, the observed patterns of subtropical
precipitation change, from 1979 to 2000, are very similar
to those in our model integrations, where ozone depletion
alone is prescribed. In both climate models and
observations, the subtropical moistening is linked to a
poleward shift of the extratropical westerly jet. Our
results highlight the importance of polar regions on the
subtropical hydrological cycle.
Fig. 4. Mechanism linking the ozone hole to subtropical
precipitation change. Shading is the zonal-mean response in
austral summer of (A and D), temperature (in K), (B and E),
zonal wind (in m s–1), and (C and F), mean meridional mass
streamfunction (in 109 kg s–1). Black solid contours in (A) and
(D) are the mean temperatures, and red dashed lines indicate
the tropopause height in the reference integrations; the arrows
illustrate the lifting of tropopause in response to ozone
depletion. Black solid (dashed) contours in (B) and (E) are
the mean westerlies (easterlies) in the reference integrations,
and the arrows illustrate the direction of extratropical
westerly jet shift. Black solid (dashed) contours in (C) and (F)
are the clockwise (counter-clockwise) mean meridional
circulation in the reference integrations, and the arrows
illustrate the direction of anomalous vertical motion induced
by ozone depletion. Top row: the coupled CMAM
integrations [experiment (i)]. Bottom row: the uncoupled
CAM3 integrations with ozone depletion confined to 40-90°S
[experiment (iv)].
Full paper here: Kang-04-22-11 (PDF)
Supplemental material: kangSOM110422 (PDF)
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UPDATE: BTW, in case anybody cares, this post went up 30 minutes AFTER the media embargo was lifted at 14:00 EST April 21. Compare that to the big argument going on over the Nisbet report. I have to agree with Keith Kloor on this one. Breaking embargoes is not only unprofessional, it is a fast track to excluding oneself from receiving any further media pre-releases. – Anthony
As several already said, the researchers probably reversed cause and effect. The amount of ozone production, mainly in the tropical stratosphere, is heavily influenced by the solar cycle: during solar maxima, some 10% more UV is produced by the sun. Thus more ozone is formed, the temperature of the stratosphere increases and the jet streams are pushed towards the poles. The latter influences rain patterns and the polar vortices. Thus at the current (still) low solar activity, we see an equatorward shift of the jet streams and a build up of the polar vortices and hence an increase in ozone depletion when there is sunlight and the stratospheric ice cloud temperatures are low enough (below -80 degr.C) at both poles.
There is no physical mechanism that links the ozone hole as cause to the jet stream shift, the opposite is far more plausible…
Walter Schneider says, over and over…
Walter, note that sometimes even a single word can route a comment through the spam filter from which the moderators always rescue it. Show patience, sir… and thank you for a very interesting (if somewhat repetitive) read…
E.M.Smith says: (April 21, 2011 at 11:05 pm) Translation: “We resent the shift of funding from ozone hole studies …
Noted. Approved. Appreciated.
This attempt at getting the Ozone Hole into climate scare has a valid reason for climate activists!
Showing that CFCs, and thus evil humanity of the industrialised, capitalist nations, caused this, had a resounding success, evidenced by the Montreal Protocol.
Now that CO2 and all the alarms seem to have stopped scaring everybody silly and willing to pay through the nose to alleviate the guilt, going back to this earlier and successful Protocol is simply the fall-back position to start a new scare and to pile on the guilt so that the money having to be paid by Western Nations doesn’t dry up.
CO2, ozone, the next climate disturbance factor produced by evil Western Nations are being used simply to wring more and more money out of the developed nations, and to bring their economies to their respective knees at the same time.
It has got nothing at all to do with proper science!
(Perhaps we should start making a list of the next factors likely to disturb the climate, which can be blamed solely on the USA and the EU …)
Is there someone here that can answer this question?
http://wattsupwiththat.com/2011/01/08/new-rate-of-stratospheric-photolysis-questions-ozone-hole/
The story linked to above pokes some pretty big holes in the Ozone hole-cliamte connection.
Columbia University is so compromised by AGW extremist belief that I would doubt anything written there until some skeptics start standing up to the peer pressure to explain everything by way of human influence.
Also, this theory, if true, means that the IPCC / CO2 obsession claims are false.
If correct, this fits nicely with my proposition that the solar induced atmospheric chemistry changes acting primarily via differential changes in ozone quantities at different levels in the atmosphere can change the vertical temperature profile, thereby altering the speed of the hydrological cycle.
In the process we also see shifts in the jetstreams and indeed shifts in all the main air circulation components giving changes in total cloudiness, global albedo and the rate of energy acquisition by the oceans.
Viv Evans says:
April 22, 2011 at 3:44 am
(Perhaps we should start making a list of the next factors likely to disturb the climate, which can be blamed solely on the USA and the EU …)
That mission is already accomplished, although the solution includes Australia and perhaps New Zealand on top of the EU & US.
It is democracy we should get rid of as soon as possible.
openDemocracy free thinking for the world
Democracy and climate change: a story of failure
David Shearman, 7 November 2007
“The political order of liberal democracy is incapable of rising to the challenge of global environmental catastrophe”.
“The case for an authoritarianism of experts has been explored with the philosophical conclusion that continuing absolute liberty cannot be preferable to life […] It may well be non-western states (including China) will find ways to deliver while the west continues to display its extreme liberty with ineffectual debate and a surrender to powerful interests in its grinding democratic institutions.”
/ bitter sarc off
Here is my full description again for those who have not yet seen it:
http://climaterealists.com/index.php?id=6645
“How The Sun Could Control Earth’s Climate”.
I have refined it more recently in a version published at Irish Weather Online but currently the link is not working.
A couple of charts.
The UAH South and North Polar lower stratosphere temperatures. Both poles show the same kind of instability in the winter (while it was assumed hat the South Pole vortex was more stable – I’m not so sure anymore).
http://img132.imageshack.us/img132/8154/uahpolarstrat.png
And then, the actual measured stratospheric Ozone over Antarctica going back to 1957. I don’t believe you would have seen this before (because they usually just show us some big blue hole over the South Pole).
I don’t find much of pattern (tied to volcanoes or the above temperature anomalies) and it doesn’t look like that big of a problem when one views the actual data.
http://img851.imageshack.us/img851/1141/southpolestratozone.png
Ozone hole huh, I’ve just watched the Arctic Blast, you know a movie that “explains” this, just like the Day After Tomorrow and dozens of others. It’s so nice that movies educate the sheep.
Here is the updated link to the most recent version:
http://www.irishweatheronline.com/irishweather/how-the-sun-could-control-earths-temperature/290.html
*****
Ferdinand Engelbeen says:
April 22, 2011 at 2:25 am
There is no physical mechanism that links the ozone hole as cause to the jet stream shift, the opposite is far more plausible…
*****
That’s my impression, too.
I noted the “Ozone Hole” and surrounding measurements of Dobsons appear to form a pattern consistent with areas of low pressure and ridges of high pressure circulating the Antarctic. The thought occurred to me that this might be associated with oceanic Chlorides and Fluorides from the raging seas of 40 plus deg. S.
No investigation appears to havebeen made of this.
hmm? how much of the added Chlorine they keep dumping in our water would be adding to the chlorine in the air?
gee heaps.
Max Hugoson says:
OZONE does NOT “protect us” from UV radiation. OZONE (O3) is FORMED by high end UV radiation hitting the atmosphere.
So what you are saying is that it is process of forming ozone which “protects” from UV. Indeed it might be more accurate to say that O2 is what is important since this is what actually removes the UV photons.
UK Marcus says:
April 21, 2011 at 3:58 pm
What creates ozone in the upper atmosphere? I understand it to be the action of the wavelength of UVB in sunlight breaking apart molecules of O2, which then reform, in a continuous process, sometimes as O3 and also O2.
What do the antarctic and arctic have something in common with each other, and nowhere else on the planet, besides a lot of ice? A 6 month day and a 6 month night.
One obvious question is why no Arctic hole?
Most likely that explanation is to be found in that one pole is an ocean surrounded by land whereas the other is a landmass surrounded by ocean.
Though if chloride ions are significent in forming a hole you’d expect one to occur more easily in the Arctic…
Jimbo says:
April 22, 2011 at 4:57 am
Just curious here but hasn’t most of the CFCs been produced in the northern hemisphere and used there? If so wouldn’t the larger hole in the Ozone layer be in the Northern polar regions.
Is there someone here that can answer this question?
Even when most of the CFC’s were used in the NH, these are distributed all over the world over time (1-2 years to reach the South Pole). CFC’s are much heavier than air, but once mixed into the air by wind, they stay mixed, due to the Brownian motion (the collisions with other air molecules which carry much heavier particulates everywhere). CFC’s even reach the stratosphere, mainly via the tropical deep convection around thunderstorms.
The difference between the poles is in the temperature: the main depletion is on the surface of ice clouds at -80 degr.C in spring with the first sunrays (that is/was the theory, as Cl2O2 only freezes out at such low temperature). Such deep temperatures readily exist in Antarctica, but only sporadic in the Arctic.
“Specifically, we show that precipitation in the Southern subtropics in austral
summer increases significantly when climate models are integrated with reduced polar ozone concentrations.” I live in the aforesaid subtropics, and over 100 years of data has failed to reveal any trend in precipitation in either summer or winter. If it didn’t happen when the world warmed over this period, how come the models predict it is going to happen? Also, the ozone hole last for a few weeks in early spring – how come it’s effect lasts all summer? The thought that the models might be wrong does not appear to have occurred to these boffins.
My goodness, I thought it had been raining a lot in the Amazon long before the 1970s. Its good to get rid of such urban legends. And yes, the climate change can be readily observed: the Amazon and presumably DRC (Africa) jungles jumped out off the ground in 40 years and amazed the parched locals. Also, with ozone capable of causing such huge changes, why do they need CO2 as well to cause change.
I guess the science wasn’t settled.
Solid according to who?
Basing the study on two defective and incomplete climate models instead of one does not qualify the work as having “solid results”. I’m sure if the study was saying taking ozone into account proved CO2 caused more warming that previously thought this study would be being slated instead of praised. Yet another study that pretends to study climate but looks at the output of computer models in the place of data.
It’s encouraging that some are finally looking beyond CO2 but the perceived success of Montreal was probably what got them the idea of creating the IPCC circus.
Actually, I was not even aware that anyone had proved there was not a ozone hole before we noticed one and started looking at it. Maybe it is a cyclic event that we never noticed. I recall a similar “discovery” in the 70’s that the gulf stream was slowing down and risked disappearing altogether bringing catastrophic canadian style weather to the whole of Europe. Then they found out it was not an uncontrolled decline but a cycle.
Maybe if we know more about the changes in the ozone layer it could explain some other trends.
In short this study just goes to show how incomplete and totally inadequate all these models are. There are two things to ask when models are described as “state-of-the-art”: firstly exactly what that “state” is and second why this is based on art instead of science.
Still , for once they’re not looking at CO2 , it’s encouraging.
Bill Illis says:
April 22, 2011 at 5:25 am
“A couple of charts.”
Any chance you could post the source of your data for those plots (particularly the ozone, I’m sure I can find the UAH data).
This does rather back up my off the cuff suggestion in my last post. It look like it could be cyclic with about a 60y period. In any case the warming kicks in around 1970 and it seems flat since around 2000. At least that matched the trends in surface temperature better than CO2 which has not flattened out.
Ferdinand Engelbeen says:
April 22, 2011 at 8:57 am
“Even when most of the CFC’s were used in the NH, these are distributed all over the world over time (1-2 years to reach the South Pole). CFC’s are much heavier than air, but once mixed into the air by wind, they stay mixed, due to the Brownian motion (the collisions with other air molecules which carry much heavier particulates everywhere). CFC’s even reach the stratosphere, mainly via the tropical deep convection around thunderstorms.”
So the concentrations of CFCs throughout the atmosphere are as great as the concentrations over the Antarctic? And the concentrations of other gases that are as heavy as CFCs are as great as the concentrations of CFCs over the Antarctic?
memoryvault says:
April 21, 2011 at 5:42 pm
Direwolf (and others)
Dupont Chemicals held the patent on CFC’s which were about to expire.
[snip]
Really, go a little lighter on the conspiracy theories. The Montreal Protocol was 44 years too late to salvage Frigidaire’s monoply on CFC formulations (actually a consortium of Frigidaire, DuPont and General Motors but the patent was assigned to Frigidaire). HCFC’s and HFC’s have been around for years. Their problem has always been that they are more expensive and less efficient than CFC’s. Current patent advantages accrue to companies finding ways to produce them more cheaply and developing mixtures with better thermodynamic efficiencies.