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Earth Science

Severe Arctic Ozone Loss 259

Posted by Soulskill
from the santa-needs-sunblock dept.
iONiUM writes "The BBC reports that 'Ozone loss over the Arctic this year was so severe that for the first time it could be called an "ozone hole" like the Antarctic one, scientists report. About 20km (13 miles) above the ground, 80% of the ozone was lost, they say. The cause was an unusually long spell of cold weather at altitude. In cold conditions, the chlorine chemicals that destroy ozone are at their most active.' This is the first time in observational history that the Arctic ozone has been depleted to such extensive levels (abstract). This will mean high UV problems for Russia, Greenland and Norway."
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Severe Arctic Ozone Loss

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  • Note to self... Don't sun-bathe in the arctic... and wear layers.

    Honestly though, it's been a while since I've seen much news about the Ozone layer. I hope people haven't forgotten that the damage done (or being done) is a problem.

    • Note to self... Don't sun-bathe in the arctic...

      Good advice for anybody living around the arctic circle, as "a day out basking in the sun" there translates into a 6 month exposure and an epic sunburn.

      • by Pieroxy (222434)

        Hmmm, I really wonder though. The sun is rarely up in the sky at these latitudes, so it is very highly unlikely that the sun's rays will go through the ozone hole and hit you. The rays that hit you go through the atmosphere much lower than the hole, so there should be no (or little) danger - at least, related to the ozone hole mentioned.

        That, and the fact that the lower the sun is in the sky, the less UV you get since it goes through the atmosphere at a steep angle traversing the ozone layer on a diagonal w

        • by praedictus (61731)
          Dont be so sure, the worst sunburn I ever got on my face was in the subarctic back around 1990 or so. Low sun + snowcover = lots of reflected UV rays. The few bits exposed to the sun got right crispified, most of the crew suffered from some degree of sunburns till we ended up getting some sunblock flown in with the provisions.
    • by dintech (998802)

      I know you're being flippant, but the damage you allude to is that being 'close' to an ozone hole causes elevated UV levels. Melanoma city, man. This has been a problem in Australia for some time because of the antarctic ozone hole. And test cricket.

  • by gatkinso (15975) on Wednesday October 05, 2011 @08:51AM (#37611010)

    The concentrations of O3 in question are quite small. Would manufacturing (or capturing surface ozone, which is a pollutant when here with us surface dwellers) O3, lofting tanks on high altitude balloons over the poles and releasing it help?

    I realize how insane this sounds.

    • Ozone has a very short half life; it breaks down quickly. It is why it is used as an oxidation sanitizer. It is also very unhealthy to be around. I can smell O3 coming from printers that need their Ozone filters replaced, but it is supposedly odorless. The funny thing is, I can't smell anything else very well.

  • by juggledean (792527) on Wednesday October 05, 2011 @09:15AM (#37611214) Homepage Journal
    It was a Nature [nature.com] article. The Weather Underground [wunderground.com] has a thoughtful discussion.
  • From TFA: "In cold conditions, the chlorine chemicals that destroy ozone are at their most active." This is wrong, because chemical reactions slow as temperatures decrease. It is an axiom in chemistry that the rate of the reaction halves (or doubles) for each 10 degree C drop (or increase) in temperature. A far as I can tell, there has been no high altitude sampling that has detected any CFCs in the Artic. This is just more environmental fear mongering and finger pointing without scientific proof.
    • In general chemical reactions will happen faster in higher temperatures. As with almost everything, this is not always the case. Some reactions have more complex kinetics required to make them happen, which can be faster or slower with an increase in temperature.

      • by LWATCDR (28044)

        If I remember correctly "It has been a long time since Chem class so I could be wrong" those tend to complex organic reactions which is not the case here.
        Since Ozone is constantly being created and destroyed in the upper atmosphere I am guessing that the lower energy means less 03 is being created so the balance between creation and destruction shifts.
        Or it could be that the colder temperatures causes the Chorine compounds to stay stable longer and do more harm.
        Or any combination. So yes the report is prob

        • Alright, you forced me into actual reading. Apparently the low temperatures reduce the rate at which the chlorine-oxide intermediate reacts with nitrogen dioxide to remove the chloride free-radical from the system. Sooner-Boomer made me mad with his "those professional scientists don't even know high school chemistry" bullshit so I went off half-cocked.

          Sorry.

    • by tbannist (230135)

      This is just more environmental fear mongering and finger pointing without scientific proof.

      Exactly how would that be different from what you're doing?

      Other than the people supposedly doing the fear mongering and finger pointing are scientists and have evidence, where as you aren't, you don't, and you have already demonstrated the depth of your ignorance on the topic. You are demonstrating the classic symptoms of the Dunning-Kruger effect [wikipedia.org].

    • Re:I call bullshit (Score:4, Insightful)

      by Sockatume (732728) on Wednesday October 05, 2011 @10:51AM (#37612432)

      That applies to a solitary chemical reaction. Atmospheric chemistry deals with equilibria. Equilibria shift with temperature.

    • Re:I call bullshit (Score:5, Informative)

      by choongiri (840652) on Wednesday October 05, 2011 @11:44AM (#37613102) Homepage Journal

      It's mostly true that reactions dependent on kinetics speed up with temperature. Ozone holes, though, are a very very different process. The ozone hole results from surface reactions on polar stratospheric clouds. The colder it gets, the easier it is for those clouds to form, and the more severe the rate of ozone depletion.

      Do some homework before calling "bullshit".

      (I am an atmospheric chemist, I am not your atmospheric chemist, etc...)

  • WTF? So we banned CFCs in the 80s to save the ozone layer but in a cruel twist of fate the increase in CO2 causes the air down here to get warmer and the air way up there to get colder and that makes the CFCs more efficient and therefore better at destroying the ozone? Yeah? So we are supposed to... do... what? How do we know that banning all carbon would not have some other unforeseen issue? These people have no idea what they are talking about or they do but are not saying anything productive. It wi
    • by siride (974284)

      The CFCs are still a problem that had lessened, but because of abnormal temperatures in the Arctic, their remaining effects were magnified a great deal.

    • by compro01 (777531)

      What we are "supposed to do" is just wait.

      the ban only took effect in 1996 (phasing out was started in 1991), with some CFCs (CFC-13, 111, 112, various halon variants, etc.) only getting fully eliminated last year.

      The issue is that CFCs are very long lived. It takes decades for them to break down. We won't really start seeing the effect of the bans on the ozone layer for another 20-30 years. Until then, we just have to deal with it.

  • Little more detail (Score:5, Informative)

    by mps01060 (1327829) on Wednesday October 05, 2011 @10:10AM (#37611872)
    These aren't traditional clouds that you see in the troposphere (lowest layer of the atmosphere). To get an ozone hole, you need VERY cold temperatures. This happens after during polar night when there is no sunlight for about half the year. The stratosphere is so cold that it can form ice crystals that contain nitric acid. These crystals act as surfaces where ozone destruction takes place. Once the sun rises at the pole (March equinox for the northern hemisphere), the UV light "splits" compounds like CFCs into reactive materials such as Chlorine. The ozone destruction reaction still will not work efficiently without the initial nitric acid/ice crystal surfaces. This is why we don't often see this happening in the Arctic, while the Antarctic shows this signal annually.

    http://www.noaa.gov/features/02_monitoring/arctic_thinning.html [noaa.gov]

    The "coldness" of the pole is related to the strength of the winds (polar vortex) around the pole in the atmosphere. The south pole generally has strong winds circling it, which works to cut off the south pole's atmosphere from the rest of the world, especially during the southern hemisphere winter. Part of the reason for a stronger vortex is due to ocean surrounding the south pole on all sides, with land masses far away. In addition, the southern hemisphere in general has more ocean compared to land than the northern hemisphere.

    In the northern hemisphere, the polar vortex generally has more waves or pertubations in the polar vortex, which help to mix in air from lower latitudes. Some of this is caused by planetary waves that propagate vertically in the atmosphere. These planetary waves are formed generally due to land masses and mountains affecting the atmospheric flow (not this simple but this is the general idea). Generally, the factor that causes the difference in the north and south polar vortices is land mass.

    Now relating this all to climate is a bit tricky. It has been seen that as the troposphere warms (lowest layer of the atmosphere), the stratosphere cools. This has been seen in observations in the last 30-50 years (you may argue that 50 years might not be enough to define a long-term trend). The reason for this cooling is basically radiative balance (though I'm oversimplifying it here). If the troposphere warms due to increased greenhouse gasses, then the atmosphere above must cool above it. There cannot be more heat coming in than is leaving the Earth. A good analog to this is Venus. Venus has huge concentrations of greenhouse gasses. We know its surface is very hot (over 400 degrees C), while its upper atmosphere is much cooler than Earth's (gets down below -110 degrees C, compared to about -80 C on Earth).

    The tough part is separating the stratospheric cooling due to greenhouse gasses and ozone destruction from CFCs (although we may know this answer once all the CFCs are out of the atmosphere in the future). Increased greenhouse gasses will warm the troposphere and cool the stratosphere. This will lead to more polar stratospheric clouds, leading to more reactions sites for ozone destruction. More ozone destruction means less UV light is absorbed by ozone in the stratosphere. Less UV absorption means a cooler stratosphere which further intensifies the problem.

    • by siride (974284)

      If I hadn't already commented in the article, I'd mod you up. Finally, someone who knows what they're talking about and doesn't want to post some knee-jerk denialist garbage.

  • by bill_mcgonigle (4333) * on Wednesday October 05, 2011 @11:48AM (#37613160) Homepage Journal

    The Science News [sciencenews.org] story has some words of caution of equating this 'hole' to the Antarctic hole:

    Geir Braathen, senior scientific officer with the World Meteorological Organization in Geneva, concurs that âoescientists have not agreed on any threshold ozone loss, like 250 or 260 Dobson units [for a hole].â Still, this atmospheric chemist cautions, âoeI would be careful about calling the Arctic depletion an ozone holeâ because it might lead people to think it's comparable to what emerges in the Antarctic. And it isnâ(TM)t.

    Antarctica's hole recurs annually, whereas mega-thinning in Arctic ozone is novel. Antarcticaâ(TM)s ozone also thins at some point to zero in a band many kilometers high. At no altitude has Arctic ozone ever fallen to zero â" even in 2011. Finally, Braathen points out, the aerial expanse and depth of the Antarctic hole greatly dwarfs the Arctic region that experienced substantial thinning earlier this year.

    âoeGoing into this Arctic spring, many of us â" myself included â" really thought this might be the year that we would see a real Arctic ozone hole,â observed Susan Solomon, of the University of Colorado, Boulder, at the recent American Chemical Society meeting in Denver. "But in the end," she says, "I think itâ(TM)s fair to say that we didnâ(TM)t.â

    It may be a matter of semantics, she concedes, but there was a rapid resupply of ozone from outside the Arctic vortex (that swirling wall of winds in the stratosphere that largely corrals a patch of atmosphere, rendering it vulnerable to ozone-destroying chemical reactions). Such a resupply does not occur in the Antarctic vortex, she notes; and that's what permits its stratospheric ozone concentrations to plummet to zero over a several-kilometer height.

    So, although the new paper clearly demonstrates that at some altitudes Arctic ozone was efficiently destroyed, Solomon says, âoeI wouldnâ(TM)t call this an ozone hole.â

    (sorry, Slashdot still protects us against dangerous quotation marks)

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