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
“which has been called the single most successful international agreement to date”
lol
That’s a quote from Kofi Annan, the guy who ran the UN at the time. Nothing like patting yourself on the back a bit? I guess the Montreal treaty is the most successfull unless you look at a few others such as Versailles, Geneva Conventions, NATO, Congress of Vienna, Maastricht Treaty, the Westphalia treaties, and maybe START 1-3.
I guess carbon dioxide is more important than global thermonuclear war?
The sun affects the size of the polar air masses via chemical processes involving ozone responding to changes in the mix of solar wavelengths and particles which also affects the size of the Antarctic ozone ‘hole’. The oceans separately affect the size of the tropical air masses and the climate zones shift to reflect the interplay over time.
Sometimes sun and oceans are in phase to supplement each others effects, sometimes out of phase to offset each others effects.
Perceived climate change at the surface is simply the net outturn of the two processes.
All new science boils a multitude of phenomena down to a simple interplay of a small number of variables. Einstein reduced so much to a simple equation involving the energy content of matter and the speed of light.
As regards Earth’s climate everything can be reduced to solar input as modified by the Earth’s internal and independently variable climate responses in the atmosphere and in the oceans.
CO2 and CFC quantities are virtually irrelevant
Magnetic effects might well be involved because as the level of solar activity varies so does the proportion of solar energy arriving as charged particles and the Earth’s magnetic field lines bring such particles in at the poles.
There then seems to be an effect on ozone quantities at the higher levels of the atmosphere such that more charged particles during a time of active sun increase ozone destruction above 45km.
Meanwhile more UV during a time of active sun appears to increase ozone creation below 45km.
However the net effect for the whole atmospheric column appears to be the higher level effect so that overall there is a net cooling of mesosphere and stratosphere when the sun is more active and a net warming of mesosphere and stratosphere when the sun is less active.
That is the only scenario that fits both the observed jetstream behaviour and the recent findings publicised by Joanna Haigh et al
P. Solar says:
April 22, 2011 at 11:13 am
—————
The ozone data came from here. Lots of data at this link.
http://www.antarctica.ac.uk/met/jds/ozone/
Lightening is fairly continuous, globally. Ever smell that garlic odor after a lighteneing strike? That’s ozone which is continuously being produced around the world. Also, by the way, anti-matter and gamma rays (reverse cosmic rays, if you will) at the same time, we just found out, (TGF”s) are produced by lightening, though how is still up for grabs. Lots of stuff going on that we do not yet understand completely nor do we yet grasp the complex interactions of these and other climatic events. So, the ozone hole along with our climate in general or any changes there to, is not proven to be due to our deoderants or freon or any other single or multiple happening that anyone has been able to actually, scientically and statistically prove within any reasonable doubt through observation. Goes for CO2 as well.
This 2005 paper by JAMES K. ANGELL, of NOAA/Air Resources Laboratory, Silver Spring, Maryland “Changes in the 300-mb North Circumpolar Vortex, 1963–2001”
“summarizes the changes in size of the 300-mb north circumpolar vortex, and quadrants, for the full period of record, 1963–2001, where the size has been defined by planimetering the area poleward of contours in the jet stream core. A contracted vortex has tended to be a deep vortex in winter but a shallow vortex in summer. During 1963–2001 there was a statistically significant decrease in vortex size of 1.5% per decade, the decrease in size of Western Hemisphere quadrants being twice that of Eastern Hemisphere quadrants. A significant increase in Arctic Oscillation (AO) index accompanies the significant decrease in vortex size, but since the vortex contracts appreciably in all four seasons, whereas the positive trend in the AO index is mainly in winter, the vortex cannot serve as a proxy for the AO index. The evidence for vortex contraction at the time of the 1976–77 regime shift is not conclusive, but there is good evidence for a 6% increase in vortex size due to the 1991 Pinatubo eruption. There is little change in vortex size following the 1982 El Chichon eruption, however. Because on average there is a significant 4% contraction of the vortex following an El Niño, it is proposed that the vortex expansion to be expected following the 1982 El Chichon eruption has been contravened by the contraction following the strong 1982–83 El Niño. There is little relation between vortex size and phase of the quasi-biennial oscillation (QBO), and the evidence for a contracted vortex near 11-yr sunspot maxima is tenuous because the vortex record extends through only three full sunspot cycles. There is a highly significant tendency for opposite vortex quadrants 0°–90°E and 90°W–180° to vary in size together, indicating either a pulsating polar vortex or the propagation of planetary wavenumber 2.”
“The vortex trace in Fig. 4 shows about a 5% increase in vortex size immediately following the Pinatubo eruption in the summer of 1991. Based on the 54-station network, the binomially smoothed north temperate 850–300-mb temperature decreased by about 0.8 K at this time, compatible with this increase in vortex size. Because it is generally accepted that the Pinatubo eruption did indeed cause a cooling of the troposphere, even on a global scale (e.g., Free and Angell 2002; Fig. 6), there seems to be no reason to doubt that the increase in vortex size following this eruption is due to the eruption.”
“Much more impressive is the significant tendency (nonoverlapping vertical bars) for the vortex to be most expanded one–two seasons before Niño-3 SST maximum, and most contracted about 1 yr after this maximum. Figure 6 shows that it is quadrant 90°W–180° (El Niño quadrant) that has the most significant tendency to be expanded near SST maximum, a finding also of Frauenfeld and Davis (2000, 2002), and contracted thereafter. Opposite quadrant 0°–90°E also shows a good tendency for contraction following the Niño-3 SST maximum.”
“The right-hand diagram in Fig. 5 indicates a tendency for contraction of the vortex near sunspot maxima, but the annual sizes are erratic, not surprising since there are only three full 11-yr solar cycles available. Figure 7 shows vortex size as a function of sunspot number, but differentiated according to whether the vortex size is in the east or west wind phase of the QBO (top trace in Fig. 4). In agreement with the findings of Labitzke (1987) and van Loon and Labitzke (1988), there is more of a tendency for vortex contraction with increase in sunspot number in the west wind than east wind phase of the QBO with, in the west wind case, significant differences in vortex size (nonoverlapping horizontal bars) for sunspot numbers less than 50 in comparison
with sunspot numbers between 100 and 150. An informative summary of this and other findings related to the possible connection between stratospheric circulation and sunspot number can be found in a recently published book by Labitzke and van Loon (1999).”
http://www.arl.noaa.gov/documents/JournalPDFs/Angell.JClimate2006.pdf
Per this September 2003 paper by Henk Eskes, Arjo Segers, and Peter van Velthoven of the Royal Netherlands Meteorological Institute (KNMI), De Bilt, The Netherlands, “Ozone Forecasts of the Stratospheric Polar Vortex Splitting Event in September 2002”
“The southern hemisphere major warming event in September 2002 has led to a break-up of the vortex in the middle and higher stratosphere and a corresponding splitting of the ozone hole. Daily 3D ozone forecasts, produced at KNMI with a tracer transport and assimilation model based on the ECMWF dynamical forecasts, provided an accurate prediction of this event a week prior to the actual break-up of the vortex. The ozone forecast model contains parametrizations for gas phase and heterogeneous chemistry. Initial states for the forecast are obtained from the assimilation of near-real time ozone data from the Global Ozone Monitoring Experiment (GOME) on ERS-2. In this paper we discuss the ozone forecasts and ozone analyses as produced before, during and after the event. These fields
are compared with ground based Dobson, ozone sonde and TOMS observations. The total ozone comparisons show that the location of the vortex edge is generally well described by the 5 to 7 day forecasts in September and October. The GOME assimilation compared with TOMS shows a good correspondence concerning vortex location and ozone features, but also reflect clear differences in the average ozone amount between the two retrieval schemes. The assimilation system produces realistic ozone profiles, apart from a systematic underestimation of ozone around 150 hPa inside the vortex in August-October.”
“the splitting of the vortex had a dramatic impact on the ozone hole, reducing it’s size and mixing ozone depleted vortex air with midlatitude air.”
In September 2002 the South Pole vortex showed a rapidly developing distortion and a subsequent split of the vortex in two more or less equal parts (Allen et al., 2003 ). On September 18 the vortex looked normal. It was displaced slightly away from the pole, but not in an unusual manner. From 21 to 23 September the vortex rapidly elongated. The process resulted in a split vortex on 24-26 September. At this time the ozone hole had been transformed into two smaller ”ozone holes” of nearly equal size. After the split the vortex remnant on the Southern Atlantic slowly gained strength and moved back to the South Pole during the first two weeks of October. The second remnant vortex over the Pacific rapidly weakened and the ozone depleted air mixed with mid-latitude air with higher ozone mixing ratios.”
“In late September and early October, Syowa is located inside the (split) vortex. Ozone values remain low until about 10 October. Then the small remaining vortex moves from the South Atlantic towards the South pole, and ozone values increase. The ozone history at Arrival Heights is very different. As soon as the vortex starts to elongate, around 21 September, the ozone hole edge passes and ozone values jump from about 170 DU to high values of about 400 DU within one day. Ozone stays very high for more than two weeks and only around 10-12 October low, ozone depleted column values of less than 200 DU are abruptly found again. This is again related to the migration of the center of the small vortex to the pole. After this the vortex weakens and moves in the direction of South America, and the ozone at Arrival Heights reaches values of around 350 DU.”
http://www.knmi.nl/~eskes/papers/jas1039_eskes_pp.pdf
This site offers Polar Vortex Forecasts;
http://db.cger.nies.go.jp/gem/moni-e/analysis/pv/index_stras.html
the Southern Hemisphere ones appear to be broken, but the Northern Hemisphere Potential Vorticity Forecast seems to work:
http://db.cger.nies.go.jp/gem/dl_graph/index_nhimg_e.php
This site offers a gallery of Stratospheric Polar Vortices;
http://www.jhu.edu/~dwaugh1/gallery_stratosphere.html
and this site offers Polar Vortex breakdown simulations:
http://www.vets.ucar.edu/vg/PV/index.shtml
Bill Illis says:
April 22, 2011 at 12:03 pm
http://www.antarctica.ac.uk/met/jds/ozone/
Thanks for the link , very informative site. Here’s one thing it reports about the accuracy of models on ozone (and even the origin measurements have a huge uncertainly):
Bill Illis says:
April 22, 2011 at 12:03 pm
http://www.antarctica.ac.uk/met/jds/ozone/
Thanks for the link , very informative site. Here’s one thing it reports about the accuracy of models on ozone (and even the origin measurements have a huge uncertainly):
That’s 100 DU of a value that ranges around 280-480 DU.
Just The Facts.
Thanks for that useful data from Angell 2005 and Eskes et al 2003.
It appears to be entirely consistent with my propositions.
Forget radiative physics. Chemical processes in the upper atmosphere are the real players in the solar effect on the global energy budget and the effect of those processes can be supplemented or offset by other internal system effects such as short term volcanic events and longer term internal ocean cycles.
All Leif Svalgaard’s objections to a solar effect are dealt with because the processes involved are chemical and not radiative and the variations involved are all essentially internal system features although showing high sensitivity to small solar variations.
DJ Hawkins:
I dislike conspiracy theories and am only interested in the facts, but Wikipedia tells me:
“In 1978 the United States banned the use of CFCs such as Freon in aerosol cans, the beginning of a long series of regulatory actions against their use. The critical DuPont manufacturing patent for Freon (“Process for Fluorinating Halohydrocarbons”, U.S. Patent #3258500) was set to expire in 1979. In conjunction with other industrial peers DuPont sponsored efforts such as the “Alliance for Responsible CFC Policy” to question anti-CFC science, but in a turnabout in 1986 DuPont, with new patents in hand, publicly condemned CFCs.[9] DuPont representatives appeared before the Montreal Protocol urging that CFCs be banned worldwide and stated that their new HCFCs would meet the worldwide demand for refrigerants.[9]”
http://en.wikipedia.org/wiki/Chlorofluorocarbon
Is this a classic example of reversing cause and effect? Or are they really just that stupid?
“Theo Goodwin says:
April 22, 2011 at 11:28 am
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?”
It is my understanding that basic physical laws of diffusion make all gases disperse more or less evenly throughout the atmosphere. I researched radon for example, whose molar mass is 222, versus an average of 29 for air, and it is fairly evenly distributed throughout the atmosphere. There is no “magnet” that attracts CFCs to the Antarctic versus anywhere else. It is just that the Antarctic also has extremely cold temperatures at times that sort of act as a “catalyst” for ozone reactions.
Stephen Wilde says:
April 23, 2011 at 12:15 am
Let’s hope so. Maybe we will have some actual physical hypotheses to replace the grand assumptions that now dominate so-called climate science. Too bad NASA cannot get its satellites to fly.
The key here is this is a process patent, not a composition patent. Folks had been making CFC based refrigerants for 50 years previously. I’ll grant that there was some marketing gamesmanship on DuPont’s part, but they weren’t the only ones who would be making HCFC’s. I’m guessing that there was a lot of “let’s jump rather than be pushed” thinking. If CFC’s were going the way of the dinosaur, you might as well try and get in the front of the marketing curve.
I’ve been following the AGW debate for years, and have recently wondered whether the “ozone hole” theory might suffer from some of the same shortcomings seen in global warming. I’ve done some basic googling and have a little knowledge on the subject now, but I am keenly aware of how easy it is to be fooled by websites with a hidden agenda. Are there any “Steve McIntyre’s” out there who specialize in ozone depletion theory? Is ozone depletion as much of a rat’s nest as AGW?
Thanks for any links to reliable, objective websites.
Dan
Photoshop Killer can tell you whether your image was Photoshopped. Just submit the suspicious image and you can get the result. JPEG file’s exif tags are used to do such classifications.