Talk:Ozone layer

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[edit] Questions about the ozone layer

Reading about ozone and the ozone layer in Wikipedia and other sources left a lot of questions to answer. So I ventured a bit farther in the field and gathered enough data about electromagnetic radiation (EMR), the properties of photons end the interaction between electrons and photons, especially in gases. My questions were not answerd by this, but I can formulate them more precisely,so here we go.Just a few for starters.

1. About ozone in the atmosphere. Above the region where the ozone layer is situated a lot of air is found and of course enough EMR with frequenties of UV or higher. So why no ozone is found there?

2. Ozone concentrations of up to 10 parts per million occur in the ozone layer, according to ENCARTA. O2 concentrations in the atmosphere is about 2 parts per 10 or 200.000 parts per million. So for every mol O3 ther are 20.000 mol O2. Why are there so few ozone molecules while there is EMR and O2 enough to produce a lot more ozone ?

4.what can the oz

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one layer do to the world?can it be stoped somehow? F.pakker 15:31, 26 Mar 2004 (UTC)

  • 1: Maybe because ozone formation is slow? See ionosphere and you'll see various gases are energized above. Note the high temperatures reached up there. Above a certain point one gets oxygen plasma instead of ozone. (SEWilco 04:58, 16 Apr 2005 (UTC))
  • 2: Ozone-oxygen cycle observes the formation rate of ozone is limited by the UV energy. (SEWilco 05:00, 16 Apr 2005 (UTC))


  • 1: There isn't a lot of air above the ozone layer ... and it's very thin. Looking at the ozone-oxygen cycle, you'll notice that the formation of the ozone takes a collision of 3 particles and thus the formation rate is proportional to the third power of the air density, the disintegration of ozone takes only a collision of 2 particles and thus the rate should be proportional to the square of the density. Therefore the relative concentration of ozone should decrease with decreasing density, everything else being equal. Icek 21:46, 17 April 2007 (UTC)

[edit] This page needs substantive revision

This page contained a number of scientifically incorrect statements. I've just corrected these, but I think the page could use a more substantive rewrite, focussing on the basic physics and chemistry of the ozone layer instead of on ozone depletion, since the latter subject has a page of its own.

--Rparson 22:04, 7 Jan 2005 (UTC)

I'm new to this wiki stuff, but can someone please correct this entry. The entire segment entered by "Barwick" is very POV, and if left on the page at all, it should be in a subsection of "Ozone depletion skeptics." Haroun Tazieff is an 80 yr old volcanologist with little experience in ozone chemistry. His opinions are fringe at best, wrong at worst. The entire entry about his work is not original, but simply cut and pasted from a conspiracy theorists webpage.

See: http://www.geocities.com/northstarzone/OZONE.html and http://www.geocities.com/northstarzone/index.html#top

Thanks, Charles Irvine

CI, you are correct. Please revert Barwicks version to the one before it... see the discusssion at Ozone depletion where he has spammed the same nonsense in. William M. Connolley 09:59, 5 November 2005 (UTC).
Just removed the geocities stuff. Not a valid source. Find a peer reviewed source or leave it out. Vsmith 14:33, 5 November 2005 (UTC)
Thanks! Keep watching though... I doubt we're finished... William M. Connolley 15:44, 5 November 2005 (UTC).

[edit] Much better now

Nice job, William and SEWilco. I just deleted some of my old text which has been made redundant by your additions. I think there are other redundancies that could be cleaned up over time. Also, I suggest moving the figure at the head of Amount of Ozone down to Ozone depletion, where it is more relevant. --Rparson 11:13, 14 Apr 2005

(William M. Connolley 20:35, 15 Apr 2005 (UTC)) Would be fine by me. Its probably best to just do things like that, and back off if anyone complains, which in this case is unlikely.
I think the figure showing "ozone amount" belongs with "Amount of Ozone". "Ozone depletion" can use improvement, but without sucking in all of the main article on the topic. (SEWilco 05:47, 16 Apr 2005 (UTC))


[edit] Care to explain how the current "ozone depletion" isn't VERY POV also?

You claim my text was my personal opinion and trying to convince people of my point of view, then explain to me how the claim that the text saying current ozone depletion and "increase in Cl and Br lately is increased markedly due to the release of large quantities of manmade organohalogen compounds, especially chlorofluorocarbons (CFCs)" isn't VERY POV also?

Because its the dominant scientific opinion supported by a large amount of research.

There is absolutely NO scienific evidence that proves this, it is simply speculation based on a correlation between CFC's being used and a decrease in ozone. It would be almost as valid to say "Joe Smith was born in Argentina in 1965, and a few years later the ozone started getting thinner, therefore Joe Smith must be a witch who's putting curses on our ozone"

No, you're just making this up. There is plenty of research, and its cited in the ozone depletion article, which is where you should be having this conversation.

There are PLENTY of other explanations for the changes in the levels of ozone, one of which is the fluctuation in natural greenhouse factors (C02, and others including water vapor which has 3 times the greenhouse effect of C02) over time, resulting in an increase (or decrease as they get lower) in earth surface temperatures, which also means that less heat escapes to the stratosphere, thereby cooling it.

I'm sure you're all familiar with this graph from Clearlight Image:Http://en.wikipedia.org/wiki/Image:Image158.gif Example of regional variations in surface air temperature for the last 1000 years, estimated from a variety of sources, including temperature-sensitive tree growth indices and written records of various kinds, largely from western Europe and eastern North America. Shown are changes in regional temperature in ° C, from the baseline value for 1900. Compiled by R. S. Bradley and J. A. Eddy based on J. T. Houghton et al., Climate Change: The IPCC Assessment, Cambridge UniversityPress, Cambridge, 1990 and published in EarthQuest, vol 5, no 1, 1991. Courtesy of Thomas Crowley, Remembrance of Things Past: Greenhouse Lessons from the Geologic Record

Sigh again. That is the good old schematic from the IPCC FAR. Things have moved on somewhat since then. William M. Connolley 15:46, 5 November 2005 (UTC).

If we were able to measure the level of Ozone as far back as 1000 AD, I would be willing to bet that the largest decrease in stratospheric temperature was around 1000 - 1400 AD, and the largest (perhaps larger than today) decrease in the level of ozone would ALSO be from 1000 - 1400 AD. Similarly, the largest incerase in stratospheric temperature would probably be around 1400 AD to 1950 AD, also with the largest increase in the level of ozone in the stratosphere.

But since we can't thats just idle speculation.

Now, just like the "manmade CFC's are the devil" argument, we can't scientifically measure either of them, and therefore you've got two choices: One, put NEITHER of them on the page or Two, put BOTH fo them on the page

Three, make you see sense, Four, keep reverting your nonsense. Sigh. William M. Connolley 15:44, 5 November 2005 (UTC).


Barwick 15:53, 5 November 2005 (UTC) WMC: You're going to have to do more than "it's generally accepted today"... 150 years ago it was generally accepted that it's ok to have blacks as slaves, that doesn't mean it was right. Today it may be "generally accepted" that manmade CFC's are the devil (after all, when the media and universities force that down our throats from the time we're born, what else CAN we believe?)

Anyone else care to chime in with something scientific, and not an "appeal to authority" like WMC continues to do?

Scientific. Tests have shown that ozone is broken down into oxygen when exposed to chlorine, which works as a catalyst. Molecular theory supports this. Chlorofluorocarbons act as a delivery system for chlorine, as they rise into the stratosphere and are broken down into their base components. Chlorine is thus introduced into the stratophere.
CFCs upset the balance of ozone and oxygen and cause ozone to be broken down faster than it can be formed. Science. What's the problem? -- Ec5618 16:09, 5 November 2005 (UTC)
Sigh. First off, you're dead wrong: wikis policy *is* to report the current consensus. If you have a personal pet theory that through sheer brilliance overturns the accepted wisdom... it doesn't belong here. As it is, you have a pile of nonsense, which also doesn't belong. Secondly, trying to introduce strawmen like "CFCs are the devil" may work in playground drebates, but not here. We've seen it all before. As for science: please continue the discussion that you've wimped out of over at ozone depletion. William M. Connolley 16:04, 5 November 2005 (UTC).

Barwick 16:18, 5 November 2005 (UTC) Ec5618: Had you been paying attention, you would have seen that I'm not disputing that the ozone is broken down by these chemicals, I'm disputing that MANMADE SOURCES are the primary cause. NOBODY can show ANY scientific evidence that it is.

No, there is plenty of evidence, what you mean is you haven't read it. Go to ozone depletion which lists it, and where this talk should be. Or read the 2002 ozone assessment: http://www.wmo.ch/web/arep/reports/ozone_2002/05_executive_summary.pdf William M. Connolley 16:59, 5 November 2005 (UTC)

Sorry, didn't see any evidence proving that the miniscule amount of manmade CFC's that reach the stratosphere are the PRIMARY CAUSE of the ozone depletion, simply another "correlation equals causation" argument is presented.

And the exact opposite to your claims is posted in another scientific article:

It is generally agreed that natural sources of tropospheric chlorine (volcanoes, ocean spray, etc.) are four to five orders of magnitude (1,d000 to 10,000 times) larger than man-made sources - Maduro, R. A.; Schauerhammer, R. The holes in the ozone scare. Washington, DC: 21st Century Science Associates; 1992.

http://www.sepp.org/ozone/ozonefranklin.html

You seem to be having problems telling "science" from "popular press"; your article falls into that category. The trop chlorine stuff is in the FAQ, of course: volcanoes, ocean stray et produce *soluble* chlorine that never reaches the stratosphere; whereas CFCs do get to the strat and there release chlorine. William M. Connolley 10:00, 6 November 2005 (UTC).

Barwick 16:40, 7 November 2005 (UTC) WMC: that's really interesting how you KNOW that no chlorine from natural sources reaches the stratosphere.

Dr. Ken Kubin, Assistant Professor department of Geology and Geophysics, University of Hawaii - "One final point that is probably worth noting is that it is important to remember that our monitoring of the exact nature of the ozone layer has only begun recently, and we have a very poor handle on what, if any, natural causes there may be for its density to change over short time intervals. Thus, although the case for the role of chlorofluorocarbons is convincing, it is difficult to say if even it is the culprit (or at least if it did or didn't have help from other gases). My own opinion is that a responsible society should always act to curtail the addition of substances deemed potentially hazardous even if there is compelling but not necessarily absolute evidence (which is the case for chlorofluorocarbons), since the balance of nature is far too complex a thing to risk toying with."

Similarly, out of the 600,000,000 tons of natural chlorine sources that enter the atmosphere, do you think that even .01% of that MIGHT reach the stratosphere, break down, and then stay there stored in the form of inorganic chlorine reservoir molecules, until they break down again and are either removed, or again become another inorganic reservoir molecule in the stratosphere? Or do you think that the filtering mechanisms are that good to remove every single possible source of natural chlorine from the atmosphere, before it reaches the stratosphere?

I don't care even what chemicals we find in the atmosphere, we could find one billion tons of CFC's there, and only one million tons of organic/inorganic chlorine compounds, but if only .000001% (10 tons) of them break down into chlorine on a yearly basis, and .1% (1,000 tons) of the other compounds break down into chlorine, then which of these two is causing the majority of the breakdown of ozone?

please provide some evidence for your assertions. No scientist denies that there is a small component to stratospheric chlorine from natural sources. However there are plenty of studies based on observations and modelling which show that the most important source of chlorine in the stratosphere is from CFCs. eg. Schauffler et. al., 2003 who made measurements in the artic winter of 2000 and found that "CFCs were the largest contributors to total organic chlorine (55–70%)". Please provide some evidence to support your ideas not idle speculation. Anyone can pull numbers out of a hat as you have.--NHSavage 22:38, 7 November 2005 (UTC)

Relevant to this discussion but missing are some questions about science and politics. First thing is why are hCFCs any safer? If we stipulate that CFCs are bad, we must continue logically to conclude that hCFCs are bad. The molecules are identical except for a little bit of Hydrogen added. Denying that these new molecules are as dangerous as the old is illogical. In fact the overall costs associated with these new refrigerants are much higher. The older CFCs are not as acidic; these new hCFCs require more robust seals. Many refrigerating systems are being scrapped or refitted(if feasible) to accommodate this acidic condition. Then there is the efficiency factor. Since the hCFCs are less efficient, there is a correspondingly greater input of energy to achieve the same output as measured in tons of ice per day. Pollution and cash outlays increase as output efficiency decreases. I have read some accusations about the patents on these chemicals(and PCBs) and the vigor of the debate being related. If anyone has access to the dates of these patents please share them.

Don't quote me on this (rparson will know for sure) but I think that HCFCs are less stable and so break up faster and so don't cause the same probs in the strat. William M. Connolley 22:56, 27 February 2006 (UTC)
WMC is correct. The lifetime of HCFCs in the troposphere is much shorter, so a far smaller percentage of the chlorine atoms reach the stratosphere. Therefore they do destroy much less ozone than CFCs. However they are also being phased out as they can still destroy statospheric ozone. The main tropospheric removal processes for these compounds are reaction with the hydroxyl radical and photolysis.--NHSavage 23:08, 27 February 2006 (UTC)
A further point: the major substitutes for CFCs are not HCFCs, but HFCs (hydrofluorocarbons) which contain no chlorine. E.g. in the US, the mandated substitute for CFC-12 in auto air conditioners is HFC-134a. HCFCs are only being used as temporary substitutes in some applications where the transition to chlorine-free substitutes is more difficult. --Rparson 16:20, 28 February 2006 (UTC)


[edit] Chapman mechanism etc

Would it make sense to merge the page on Ozone-oxygen cycle to here? I am not very happy with that page - too small really and does not really to my mind get across the essentially cyclic nature of the Chapman cycle. It would be nice to include the standard exercise calculating the expected ozone concentations which one gets from the Chapman cycle (time to dig out some old notes...) and explain that this concentration is wrong because of the catalytic destruction reactions. These could then be listed.--NHSavage 21:55, 11 March 2006 (UTC)

Seems sensible to me. That article always seemed to be something of an outlier. BTW, I haven't ever seen it referred to as the "ozone-oxygen cycle" anyway, it's always been "Chapman Mechanism" or "Chapman Cycle", but that just might reflect the sources that I tend to read.--Rparson 03:20, 14 March 2006 (UTC)

[edit] More details requested

I'd like to see more details (numbers) on what happens in the ozone layer. Specifically:

  • The article says that the ozone layer does not occur higher because the oxygen is ionized. Why does it not occur lower (this may have been answered already; I'll have to look again more closely)? How much of the ionization is due to UV?
  • Does UV have some unusual affinity for O3, as opposed to O1, O2 or N? We have an entire atmosphere worth of oxygen molecules. Can we get some figures on how much UV is stopped by the ionized oxygen, etc.?
  • The idea behind natural selection is that beings adjust to their environment. Is there any reason to believe that this would not happen with increased UV? Note, I'm not asking whether we would like it or not. :) I've also seen mention that suntan lotion may be responsible for some skin cancer, along with the fact that we apparently made do without suntan lotion for many thousands of years.
  • What percentage of total UV is filtered out at each step? If the amount of ozone would only be a few millimeters thick at sea-level, then it seems like ozone alone would not catch much.

--Scott McNay 23:33, 12 March 2007 (UTC)

I can give partial answers to 2 of your questions:

  • I think the ozone layer has got a lower limit because there isn't enough atomic oxygen in the troposphere, because there isn't enough UV radiation to create it, because this UV radiation is blocked by the ozone layer.
  • Evolutionarily you would probably see the same thing that you already see nowadays in native populations (i.e. living there for many millenia) of high-insolation countries vs. low-insolation countries: The skin will darken. Of course that doesn't take into account changes in lifestyle, sunscreen etc. Icek 06:49, 18 April 2007 (UTC)

Icek 06:49, 18 April 2007 (UTC)

[edit] Please somebody explain this to me.

The article doesn't give the "thickness" (that is, distance from bottom to top) of the ozone layer. This link from Caltech gives information that I would like to see explained in the article. http://coolcosmos.ipac.caltech.edu/cosmic_kids/AskKids/earthozone.shtml --70.131.51.64 09:09, 29 March 2007 (UTC)

Its not a very good answer. Thats the thickness it would have if it were just a layer of pure ozone (at SLP?). The thickness of the atmos layer that ozone occurs in in is ?30 km? William M. Connolley 09:21, 29 March 2007 (UTC)

[edit] State of regulation on bromofluorocarbons

Bromofluorocarbons, which besides CFC's also have high ozone depletion value, have not been described, in regard to regulation (by industrial and developing countries). As besides CFC's this too has extremely high ozone depletion value it should be described. Besides this, there should be a list or reference in what products CFC's and bromofluorocarbons are present (as still sold in developing countries). KVDP 13:06, 30 Mar 2004 (UTC)

[edit] Why does it exist?

The article mentions that "stratospheric ozone is produced by solar UV radiation", but that's the extent to which it's discussed. Could a knowledgeable person write a section explaining why the ozone layer exists? (Prompted by a short unsigned question over at Talk:Ozone depletion.) Tempshill 16:37, 23 May 2007 (UTC)

There used to be a section on this, but some vandal deleted it way back when and it was never restored. I've put it back in.--Rparson 21:36, 24 May 2007 (UTC)

[edit] why is no one paying attention to the hole in the ozone layer anymore?

why is it not as much of an issue as global warming? AbsoluteZero255 18:48, 25 October 2007 (UTC)

The usual answer to "why" is "money". But the article needs sources which state why before the article can state why. (SEWilco 19:10, 25 October 2007 (UTC))

Because Gore wouldn't get a Nobel for that —Preceding unsigned comment added by 217.67.17.234 (talk) 15:17, 12 December 2007 (UTC) this means the ozone layer is tres inportant —Preceding unsigned comment added by 75.155.110.64 (talk) 18:21, 19 May 2008 (UTC)