Researchers find that the extremes in Antarctic ozone holes have not been matched in the Arctic

Apr 14, 2014
Ozone hole during Oct. 7, 2008, as measured by the Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) atmospheric sensor onboard ESA's Envisat. Credit: KNMI/ESA

Since the discovery of the Antarctic ozone hole, scientists, policymakers, and the public have wondered whether we might someday see a similarly extreme depletion of ozone over the Arctic.

But a new MIT study finds some cause for optimism: Ozone levels in the Arctic haven't yet sunk to the extreme lows seen in Antarctica, in part because international efforts to limit -depleting chemicals have been successful.

"While there is certainly some depletion of Arctic ozone, the extremes of Antarctica so far are very different from what we find in the Arctic, even in the coldest years," says Susan Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science at MIT, and lead author of a paper published this week in the Proceedings of the National Academy of Sciences.

Frigid temperatures can spur because they create prime conditions for the formation of polar stratospheric clouds. When sunlight hits these clouds, it sparks a reaction between chlorine from chlorofluorocarbons (CFCs), human-made chemicals once used for refrigerants, foam blowing, and other applications—ultimately destroying ozone.

"A success story of science and policy"

After the ozone-attacking properties of CFCs were discovered in the 1980s, countries across the world agreed to phase out their use as part of the 1987 Montreal Protocol treaty. While CFCs are no longer in use, those emitted years ago remain in the atmosphere. As a result, atmospheric concentrations have peaked and are now slowly declining, but it will be several decades before CFCs are totally eliminated from the environment—meaning there is still some risk of caused by CFCs.

"It's really a success story of science and policy, where the right things were done just in time to avoid broader environmental damage," says Solomon, who made some of the first measurements in Antarctica that pointed toward CFCs as the primary cause of the ozone hole.

To obtain their findings, the researchers used balloon and satellite data from the heart of the over both polar regions. They found that Arctic did drop significantly during an extended period of unusual cold in the spring of 2011. While this dip did depress ozone levels, the decrease was nowhere near as drastic as the nearly complete loss of ozone in the heart of the layer seen in many years in Antarctica.

The MIT team's work also helps to show chemical reasons for the differences, demonstrating that ozone loss in Antarctica is closely associated with reduced levels of nitric acid in air that is colder than that in the Arctic.

"We'll continue to have cold years with extreme Antarctic ozone holes for a long time to come," Solomon says. "We can't be sure that there will never be extreme Arctic ozone losses in an unusually cold future year, but so far, so good—and that's good news."

Explore further: Study reveals four new man-made gases in the atmosphere

More information: "Fundamental differences between Arctic and Antarctic ozone depletion," by Susan Solomon, Jessica Haskins, Diane J. Ivy, and Flora Min. PNAS, 2014. www.pnas.org/cgi/doi/10.1073/pnas.1319307111

add to favorites email to friend print save as pdf

Related Stories

Is the ozone layer on the road to recovery?

Feb 10, 2013

(Phys.org)—Satellites show that the recent ozone hole over Antarctica was the smallest seen in the past decade. Long-term observations also reveal that Earth's ozone has been strengthening following international ...

Study pinpoints causes of 2011 Arctic ozone hole

Mar 11, 2013

(Phys.org) —A combination of extreme cold temperatures, man-made chemicals and a stagnant atmosphere were behind what became known as the Arctic ozone hole of 2011, a new NASA study finds.

UN hails 25-year ozone treaty for preventing disaster

Sep 14, 2012

The United Nations treaty to protect the ozone layer signed nearly 25 years ago prevented an environmental disaster, a chief UN scientist said Friday, cautioning though that the Earth's radiation shield is ...

Ozone layer faces record 40 pct loss over Arctic

Apr 05, 2011

(AP) -- The protective ozone layer in the Arctic that keeps out the sun's most damaging rays - ultraviolet radiation - has thinned about 40 percent this winter, a record drop, the U.N. weather agency said ...

Recommended for you

Erosion may trigger earthquakes

Nov 21, 2014

Researchers from laboratories at Géosciences Rennes (CNRS/Université de Rennes 1), Géosciences Montpellier (CNRS/Université de Montpellier 2) and Institut de Physique du Globe de Paris (CNRS/IPGP/Université Paris Diderot), ...

Strong undersea earthquake hits eastern Indonesia

Nov 21, 2014

A strong undersea earthquake hit off the coast of eastern Indonesia on Friday, but there were no immediate reports of injuries or serious damage and officials said it was unlikely to trigger a tsunami.

User comments : 8

Adjust slider to filter visible comments by rank

Display comments: newest first

aksdad
3 / 5 (6) Apr 14, 2014
Almost 90% of Earth's population lives in the northern hemisphere, far closer to the Arctic than Antarctica. It seems CFC's would be more likely to accumulate in the Arctic and cause more ozone depletion than over Antarctica, yet the opposite effect is observed. Why?

Also, despite measurable reductions of CFC's in the atmosphere since the Montreal Protocol in 1987, the ozone hole size over Antarctica and the amount of ozone remains virtually the same as 25 years ago. Why?

Atmospheric CFC decline
http://www.esrl.n...ata.html

The science behind the interaction of CFC's and ozone (in the lab) seems to be well understood, but is the actual impact on atmospheric ozone, especially over the poles, not as straightforward as was thought?
tdw
2.5 / 5 (6) Apr 14, 2014
Has there ever not been an ozone hole? How do we know it is not a natural phenomenon?
Skepticus
2 / 5 (4) Apr 15, 2014
Hear, hear. The backside holes defend the honor of the O-holes.
antialias_physorg
4.2 / 5 (10) Apr 15, 2014
Has there ever not been an ozone hole? How do we know it is not a natural phenomenon?

There are annual ozon depletion spikes, But when it was measured (in the 70s and 80s) it got steadily worse by a significant margin year after year. There is no way that could have been natural variation.

A success story of science and policy

It's sort of sad to watch how world leaders have gotten so much dumber since then. CFCs and ozone is such an 'abstract' issue compared to climate change. Yet back then people were knowledgeable enough that they knew they must act - even against the interests of big business.
Shootist
2.1 / 5 (7) Apr 15, 2014
Researchers also discover, but fail to note, that air circulation between the Northern and Southern Hemispheres is too slow for CFCs, released in the North, to have caused any effect south of 0 degrees latitude. Of course we've KNOWN this since the 1950s, but the boffins lied and said CFCs (from the North) are killing the ozone (in the south).

No. But duPont's patent on CFC was going to expire so the US made CFCs illegal, so duPont could sell it's new Patented CFC replacement. FACT.

Keep voting leftist. You fools.
runrig
4.4 / 5 (7) Apr 15, 2014
Almost 90% of Earth's population lives in the northern hemisphere, far closer to the Arctic than Antarctica. It seems CFC's would be more likely to accumulate in the Arctic and cause more ozone depletion than over Antarctica, yet the opposite effect is observed. Why?


Because Stratospheric temperatures are colder over Antarctica than over the Arctic and as such the O3 killing reaction only really takes place in Antarctica. There is a difference of around 10C. ~MS80C vs ~MS90C. Though this year the Arctic Strat vortex core did reach ~MS90C for a time. That's probably the reason why there are O3 holes floating about now. One has recently been over the UK.

Explained here....
http://www.esrl.n.../Q10.pdf
runrig
4.3 / 5 (6) Apr 15, 2014
Researchers also discover, but fail to note, that air circulation between the Northern and Southern Hemispheres is too slow for CFCs, released in the North, to have caused any effect south of 0 degrees latitude. Of course we've KNOWN this since the 1950s, but the boffins lied and said CFCs (from the North) are killing the ozone (in the south).
.................

Keep voting leftist. You fools.


Complete and utter bollocks...............
Not in the Stratosphere you idiot.

There is a natural circulation current called the BDC (Brewer Dobson circulation) that transports air and O3 from the Tropics to the Poles, and hence will CFC's as well.

I suggest you learn something before you utter on here my friend.

Actually its the first post I've seen from you that isn't about Dyson and/or Polar bears.

Now I know why ... called you it at the outset.
dickclarkshead
not rated yet Apr 19, 2014


"No. But duPont's patent on CFC was going to expire so the US made CFCs illegal, so duPont could sell it's new Patented CFC replacement. FACT."

Read more at: http://phys.org/n...tml#jCp"

Additionally the data set from the surveys over time is VERY short in terms of studies of this phenomena. To arrive at validation knowing this fact can obviously be used to acquire funding from whatever entity to continue endeavors in whatever field topic once the funding is secured, a well known manipulation in the scientific community. Moreover Dupont on the border of the U.S. and Canada has been under notable upheaval in the world market due in part to other countries creating acquirable sources for the CFC product line.
The jury is still out on HCFC's and other blends of synthetic refrigerants atmospheric effects. Obviously a funded study is in the works to be manipulated by whatever entity secures it...and so it goes.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.