First, a clarification; while the AGU calls it an “ozone hole”, it technically isn’t. As NASA says here, it really isn’t a “hole” in the true sense of the word, it is simply a region of reduced O3 concentration that periodically changes in size, shape, and density. -Anthony
Ozone hole might slightly warm planet
AGU Release No. 13-39
WASHINGTON, DC—A lot of people mix up the ozone hole and global warming, believing the hole is a major cause of the world’s increasing average temperature. Scientists, on the other hand, have long attributed a small cooling effect to the ozone shortage in the hole.
Now a new computer-modeling study suggests that the ozone hole might actually have a slight warming influence, but because of its effect on winds, not temperatures. The new research suggests that shifting wind patterns caused by the ozone hole push clouds farther toward the South Pole, reducing the amount of radiation the clouds reflect and possibly causing a bit of warming rather than cooling.
“We were surprised this effect happened just by shifting the jet stream and the clouds,” said lead author Kevin Grise, a climate scientist at Lamont-Doherty Earth Observatory of Columbia University in New York City.
Grise notes this small warming effect may be important for climatologists trying to predict the future of Southern Hemisphere climate.
The work is detailed in Geophysical Research Letters, a journal of the American Geophysical Union. Grise collaborated on the study with Lorenzo Polvani of Columbia University, George Tselioudis of NASA Goddard Institute for Space Studies, Yutian Wu of New York University, and Mark Zelinka of Lawrence Livermore National Laboratory.
Hole in the sky
Each ozone molecule consists of three oxygen atoms bound together. These ozone molecules gather in the lower portion of the stratosphere about 20 to 30 kilometers (12 to 19 miles) above the ground—about twice as high as commercial airliners fly.
Thankfully for the living things below, this layer of ozone shields Earth from some of the hazardous ultraviolet radiation barraging the atmosphere. Unchecked, these ultraviolet rays can cause sunburns, eye damage and even skin cancer.
In the 1980s, scientists discovered thinning of the ozone layer above Antarctica during the Southern Hemisphere’s spring months. The cause of this “hole” turned out to be chlorofluorocarbons, such as Freon, from cooling systems, aerosols cans and degreasing solvents, which break apart ozone molecules. Even though the1987 Montreal Protocol banned these chlorofluorocarbons worldwide, the ozone hole persists decades later.
Many people falsely equate the ozone hole to global warming. In a 2010 Yale University poll, 61 percent of those surveyed believed the ozone hole significantly contributed to global warming. Additionally, 43 percent agreed with the statement “if we stopped punching holes in the ozone layer with rockets, it would reduce global warming”.
An actual consequence of the ozone hole is its odd effect on the Southern Hemisphere polar jet stream, the fast flowing air currents encircling the South Pole. Despite the ozone hole only appearing during the spring months, throughout each subsequent summer the high-speed jet stream swings south toward the pole.
“For some reason when you put an ozone hole in the Southern Hemisphere during springtime, you get this robust poleward shift in the jet stream during the following summer season,” said Grise. “People have been looking at this for 10 years and there’s still no real answer of why this happens.”
Cloud reflection
The team of scientists led by Grise wondered if the ozone hole’s impacts on the jet stream would have any indirect effects on the cloud cover. Using computer models, they worked out how the clouds would react to changing winds.
“Because the jet stream shifts, the storm systems move along with it toward the pole,” said Grise. “If the storm systems move, the cloud system is going to move with it.”
High- and mid-level clouds, the team discovered, traveled with the shifting jet stream toward the South Pole and the Antarctic continent. Low-level cloud coverage dropped in their models throughout the Southern Ocean. While modeling clouds is a difficult task due to the variety of factors that guide their formation and movement, Grise noted that observational evidence from the International Satellite Cloud Climatology Project, a decades-long NASA effort to map global cloud distributions, supports their theory of migrating cloud coverage.
When the cloud cover moves poleward, the amount of energy the clouds can reflect drops, which increases the amount of radiation reaching the ground. “If you shift the reflector poleward,” Grise explained, “you’ve moved it somewhere there is less radiation coming in.”
In 2007, the Intergovernmental Panel on Climate Change reported a direct cooling effect from the thinning ozone layer—specifically, a reduction of about 0.05 watts per square meter’s worth of energy reaching the ground. However, Grise and his colleagues estimated the indirect effect of the shifting cloud coverage to be an increase of approximately 0.2 watts per square meter. Their result not only suggests that warming rather than cooling would be taking place, but also that there’s a larger influence overall. Since the jet stream only shifts during the summer months, the warming only takes place in those months.
“Theoretically this net radiation input into the system should give some sort of temperature increase, but it’s unknown if that signal could be detected or what the magnitude of it would be,” said Grise. For comparison, worldwide, an average of about 175 watts per square meter reaches the ground from sunlight, according to the George Washington University Solar Institute.
Dennis Hartmann, an atmospheric scientist at the University of Washington in Seattle unrelated with the project, points out that since predicting cloud behavior is so challenging, the model used in Grise’s study could be underestimating clouds north of the jet stream being pulled toward the equator and in turn reflecting more light, potentially reducing or even negating the warming effect. Hartmann added that he also has some concerns about the modeling of the low-level cloud response.
Still, “this is certainly a very interesting topic and potentially important from a practical perspective of predicting Southern Hemisphere climate and even global warming rates,” he commented.
Climate tug-of-war
Looking toward the future, the jet stream should do less and less shifting to the south during the summer months as the ozone layer above the South Pole recovers. However, increasing levels of greenhouse gases can also change mid-latitude wind patterns and push the jet stream poleward, creating a complicated scenario which Grise said he plans to study in future work.
“You have sort of this tug-of-war between the jet being pulled equator-ward during the summer because of the ozone recovery and the greenhouse gases pulling the jet further poleward,” said Grise. “What the clouds do in that scenario is an open question.”
Funding for the research was provided by the National Science Foundation and by the U.S. Department of Energy’s Office of Science.
Notes for Journalists: Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this article by clicking on the following link:
http://onlinelibrary.wiley.com/doi/10.1002/grl.50675/abstract
Or, you may order a copy of the paper by emailing your request to Thomas Sumner. Please provide your name, the name of your publication, and your phone number.
Neither the paper nor this press release is under embargo.
Title:
The Ozone Hole Indirect Effect: Cloud-Radiative Anomalies Accompanying the Poleward Shift of the Eddy-Driven Jet in the Southern Hemisphere
Authors:
Kevin M. Grise: Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
Lorenzo M. Polvani: Department of Applied Physics and Applied Mathematics, and Department of Earth and Environmental Sciences, Columbia University, New York, New York, USA;
George Tselioudis: NASA Goddard Institute for Space Studies, New York, New York, USA;
Yutian Wu: Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, New York, New York, USA;
Mark D. Zelinka: Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, California, USA.
Contact information for the authors:
Kevin Grise, +1 (845) 735-3802, Email: kgrise@ldeo.columbia.edu
Lorenzo Polvani, +1 (212) 854-7331, Email: lmp@columbia.edu
Barrie Sellers says:
August 9, 2013 at 6:55 am
“The half life of ozone at -50degrees C is 3 months – there’s your ozone hole. As soon as the sun goes down. and the UV rays stop producing more ozone. the ozone hole gets bigger until the sun returns.”
Exactly. The ozone hole is a region of stagnant air surrounded by the polar vortex. It has no effect on climate. The action is in the polar vortex which surrounds the hole, specifically the temperature inversion which can form. With a temperature inversion (active sun) downflow in the vortex is reduced and polar air stays isolated in the polar region. Without it, polar air is free to move southward, mainly over continental interiors (blocking). This theory is not yet ready for textbooks (conflicts with AGW).
HenryP
We share the conclusion but our descriptions as to how one gets there differ somewhat.
An active sun reduces ozone at higher levels (above 45km). That cools both mesosphere and stratosphere. Conventional climatology says that an active sun creates more ozone. That may be so below 45km but it is the changes above 45km that appear to dominate because we saw that the period of active sun was accompanied by a cooling stratosphere and now that the sun is less active the stratosphere is no longer cooling and may be warming, ozone is increasing above 45km and the ozone holes are shrinking.
When the stratosphere above the poles cools relative to the stratosphere above the equator as happens when the sun is more active the tropopause height above the poles rises relative to tropopause height above the equator,.the polar vortex shrinks horizontallly and the entire global air circulation is pulled poleward in both hemispheres.
Global cloudiness is decreased as the subtropical high pressure cells expand and more energy enters the oceans for net warming.
The opposite when the sun is less active.
At some specific level of solar activity global cloudiness and albedo switches the system to and fro between net warming or net cooling via changes in the amount of solar energy able to enter the oceans.
In order to achieve that which is observed it is essential to reverse the sign of the effect of solar activity on the atmosphere which is something that Joanna Haigh said might be necessary.
However I think she and her colleagues are still hung up on the conventional view of active sun warming the stratosphere.
It was as a result of that hangup that AGW theory came to the fore as a possible non solar reason for the cooling stratosphere when the sun was more active.
An active sun must cool the stratosphere because the same pattern of climate change occurred in the MWP (and the previous warm spells) long before the Industrial Revolution.
It cannot have been CO2 causing the cooling stratosphere when the sun was more active because the whole scenario went into reverse in the late 90s when the sun declined from the high level of activity of cycle 23 and the increased meridionality with recovering ozone and warming stratosphere have all occurred despite a considerable increase in our CO2 emissions.
Observations have invalidated AGW theory.
My recollectiion of the initial discovery of the ozone hole was that it was almost immediately followed by alarmism, and an assumption that it was an unnatural, man-caused phenomenon. We had no previous knowledge of this thing, yet we jumped to costly, probably ineffectual solutions. And now, here we are30 years later, and those same silly assumptions hold sway over most of the world. It was partially because of the ozone hole alarmism phenomenon that I almost automatically dismissed CAGW alarmism when I first heard its CO2 hypothesis. Of course, one bit of alarmism being stupid, premature, wrong, etc. does not preclude another bit of alarmism from being plausible or even likely. But since it was the same basic interests promoting both bits, I decided to watch my wallet, and wait for some real science to make a good case before I’d jump on the band wagon. I’m still waiting.
Henry@Reno
Ozone loss due to CFC’s was a red herring
(although I believed it and personally helped to get rid of the CFC’s )
It appears that the decrease noted from 1951-1995 was natural.
Heat gain due to CO2 increase is simply not happening
http://blogs.24.com/henryp/2013/04/29/the-climate-is-changing/
It is not my fault the scientists got it wrong.
Stephen says
We share the conclusion but our descriptions as to how one gets there differ somewhat.
An active sun reduces ozone at higher levels (above 45km).
Henry says
It is important to note that we did reach the same conclusion looking at it from different angles.
This is how science progresses. As far as ozone is concerned, I remember looking at a station in the Swiss Alps with data from 1927. It was good enough to find a bending point of 1951 (corresponding with an increase of warmth from that date)
and increase in ozone since 1995 and decrease of warmth since 1995.
I don’t know what height they measured, but it must have been below 45 km…….
The SH data came from a graph from the SS.
I am sure that must be right???
Henry.
Not sure how reliable ozone and temperature records are historically.
Also not sure about regional divergences from the general principle.
Best to focus on modern sensing techniques and see what transpires.
Either I’ve nailed it or I haven’t and only Nature will tell me.
In the 1980s, scientists discovered thinning of the ozone layer above Antarctica during the Southern Hemisphere’s spring months. The cause of this “hole” turned out to be chlorofluorocarbons, such as Freon, from cooling systems, aerosols cans and degreasing solvents, which break apart ozone molecules. Even though the1987 Montreal Protocol banned these chlorofluorocarbons worldwide, the ozone hole persists decades later.
Petitio principii: How do they know for certain that the Ozone depletion/thinning hasn’t always been there? Just because measurements were made in the 50s with primitive yet state of the art equipment then measurements were made in the 80s with superior state of the art equipment 30 years later, but still primitive by today’s standards, suggesting that quality of measurement could be an issue.
As to this study with yet another puter model? When one reads with a wry smile the UK Wet Office’s summary explanation to DEFRA, for the 2012 wash out Spring/Summer/Autumn (fall), the excuses one after another as to why it is very difficult t make predictions, especially about the future, & how little is fully understood about the drivers of climate, it would appear that this study should be taken with pinch of salt, although I would suggest that it be part of your recommended daily intake, to keep the Drs happy!!! 😉
Henry.
Ozone measurements in the troposphere, especially near the surface, are a whole different matter to ozone above the tropopause.
Not remotely comparable.
” it would appear that this study should be taken with pinch of salt,”
Maybe.
But bear in mind that ozone concentrations are a proxy for atmospheric temperatures above the tropopause and it is well known that stratosphere temperature changes affect the height of the tropopause.
Then bear in mind that the gradient of tropopause height between equator and poles affects the latitudinal position of all the permanent climate zones and the jet streams.
All one needs to do to shift the whole lot equatorward or poleward is to change the gradient of that slope.
So I think they are stumbling towards my solution as are many others at present.
Stephen says
Not sure how reliable ozone and temperature records are historically.
Henry@Stephen Fisher
I am convinced my temp.data (from 1974) are correct. I took several precautionary measures.
e.g. Spencer (UAH) gets the same result on the warming rate in degrees C per annum for the past 30 years as myself.
True, the SS graph on ozone only had more recent data, clearly showing a big increase since 1995,; the question is : where did you find ozone data from >45 km?
Gary Pearse says: August 9, 2013 at 5:07 am
Check out also if the gas-ratio relationship is reversed in temperate-equatorial regions. Just the facts, you are seeing a barrier keeping these gases out, I think my theory is stronger that they are being shoved out. Hmm… “Pearse Effect”? See my fuller explanation and prediction at:
August 8, 2013 at 4:56 pm
I think the “barrier” versus “shove out” question is just semantics/phase, i.e. conceptually it is similar to the eyewall of a hurricane;
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/hurr/stages/cane/wall.rxml
as the polar vortex forms/drops it creates a low pressure area/shoves out much of the gases that were there before and then the wall of the vortex serves as a barrier that prevents the gases from returning, i.e.:
http://opendx.informatics.jax.org/cds/proceedings96/cart/csfig211.jpeg
I think the real question here is the “effect”, i.e. are the “holes” a result of the Coriolis Effect or the Pearse Effect. In this case, there appears to be ample evidence of the impact of the Coriolis Effect and thus far I’ve seen no observational evidence to support the existance of the Pearse Effect. Furthermore, even if the Pearse Effect exists, it would likely be a minor variable and easily overwhelmed by the Coriolis Effect, e.g.:
Mickey Reno says: August 9, 2013 at 8:58 am
My recollectiion of the initial discovery of the ozone hole was that it was almost immediately followed by alarmism, and an assumption that it was an unnatural, man-caused phenomenon.
Yep, a strong sense of Déjà vu…
Time – Feb 17, 1992
M Courtney says: August 8, 2013 at 2:16 pm
Also, it was my understanding that a smaller ozone hole had been observed at the north pole. That would blow the idea out of the water (no problems, these things do happen).
Yes, it’s the same effect as I noted above, when a polar vortex forms in the Northern Hemisphere, you also get an “ozone hole”:
http://ozonewatch.gsfc.nasa.gov/facts/vortex_NH.html
The first thing to check is whether the hole is centred on the magnetic S Pole, the actual S Pole or the centre of the land mass.
The “hole” is not centered around “the magnetic S Pole, the actual S Pole or the centre of the land mass”, “The ozone hole is in the center of a spiraling mass of air over the Antarctic that is called the polar vortex. The vortex is not stationary and sometimes moves as far north as the southern half of South America, taking the ozone hole with it.”
http://www.nasa.gov/centers/langley/news/factsheets/HALOE-Ozone.html
HenryP asked:
“where did you find ozone data from >45 km?”
http://www.nature.com/nature/journal/v467/n7316/abs/nature09426.html
“these spectral changes appear to have led to a significant decline from 2004 to 2007 in stratospheric ozone below an altitude of 45 km, with an increase above this altitude.”
“our findings raise the possibility that the effects of solar variability on temperature throughout the atmosphere may be contrary to current expectations.”
I’d be interested in hearing what has happened since 2007.
Stephen says
http://wattsupwiththat.com/2013/08/08/ozone-hole-may-be-a-warming-factor-due-to-wind-shifts/#comment-1385596
henry says
sorry, this cannot possibly qualify
there are no actual reported measurements?
Well you could pay for the whole paper. I’m sure there will be actual measurements there.
Keith says: @ur momisugly August 9, 2013 at 2:57 am
….I too remember that prediction. You’d think it was made by somebody with a deep understanding of solar cycles. If it’s really the case that solar activity (particularly UV and EUV) is what determines the size of the ozone ‘hole’, then that would also fit….
>>>>>>>>>>>>>>>>>>>>>>>>
The information was out there.
By 1965 the Milankovitch cycles were known and starting to be confirmed by hard evidence.
88 yr Geissenberg cycle (1939 & 1971) SEE: http://virtualacademia.com/pdf/cli267_293.pdf
Remember in the early seventies the media was still hyping the ‘Coming Ice Age’ See: http://www.climatedepot.com/2009/10/06/dont-miss-it-climate-depots-factsheet-on-1970s-coming-ice-age-claims-2/
Yet in the middle of the Ice Age hype at the 1972 First Earth Summit, Maurice Strong first mentions Global Warming and tells Greenpeace to “go home and raise hell” This is when we were still at the bottom of a cold cycle. Hansen’s US temp Graph
The history of the science at that time:
If the climate was to be used as a political weapon the UN had to move fast to deflect the “profusion of information and discussion on this subject.”
Shahinaz M. Yousef in his paper THE SOLAR WOLF-GLEISSBERG CYCLE AND ITS INFLUENCE ON THE EARTH says…
I think the UN/Strong was well aware we were looking at the beginning of ‘Global Warming’ in 1972 and was jumping in at the bottom of the ramp hoping for a forty year increase in temperature that could be attributed to CO2.
they are full of BS!
Stephen says
Well you could pay for the whole paper. I’m sure there will be actual measurements there.
Henry says
measure ozone at >45 km height?
how?
\from what year onward? how long since then? (which is relevant, in the light of my own findings)
unfortunately nobody is paying me for my hobby so I cannot pay for the results
but if you cannot produce those results I would be careful in promoting them…
When solar activity is low, it is the distribution of ozone that changes in a vertical and horizontal sense that causes the polar regions to warm relative to the lower latitudes which in turn gives a more meridional atmospheric circulation for the N.H., which in turn results in more low clouds, more snow cover ,and greater amounts of precipitation for the N.H., hence a higher albedo and lower temp.
The amounts of ozone going up or downin concentrations with high or low solar activity I think is not of most importance,rather it is where the ozone is relative to the atmosphere both in a vertical and horizontal sense.
Although I think on balance unlike Stephen, that ozone levels probably decrease during very low solar periods due to very weak UV emissions.
I know solar storms during active solar periods also destroy ozone but I think the intensity of UV light versus ozone overides solar storm contributions to the amounts of ozone that may be present.r.
However I think a prolonged solar minimum with a few active spurts from time to time probably results in ozone concentrations to be at their lowest.
Sakvatore del prete says
they are full of BS!
henry asks
your comment does not make any sense
who is they? Why? what? how?
please stop this idiotic approach to conversation, leif
They are the ones that keep trying to promote the AGW theory and will use any means to do it, nomatter how ridiculous it is. Don’t you get tired of it? I do and these people will not look at the data in an objective manner and constantly spin it to make themselves look correct even when wrong.
An example would be their explanation for the recent severe winters, is low arctic sea ice, which is the cause of a more meridional atmospheric circulation.
The correlation does not hold up if one looks at past history,although the correlation with prolonged minimum solar periods does in contrast.
Their theory will be toast before this decade ends, despite their efforts.
SvP says
When solar activity is low, it is the distribution of ozone that changes in a vertical and horizontal sense that causes the polar regions to warm relative to the lower latitudes
henry
we (several of us) proved the opposite
please
ET,
go home
and RIP
If you look they use the bogus greenhouse gasses in this article. Had to get it in, and really takes away from this article, in my opinion.
Henry I am curious about what you think the role of ozone is on the climate and how it may relate to solar activity.