GRA
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GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Mon Nov 05, 2018 7:23 pm

https://www.greencarcongress.com/2018/1 ... ozone.html
The ozone hole that forms in the upper atmosphere over Antarctica each September was slightly above average size in 2018, NOAA and NASA scientists reported. Colder-than-average temperatures in the Antarctic stratosphere created ideal conditions for destroying ozone this year, but declining levels of ozone-depleting chemicals prevented the hole from as being as large as it would have been 20 years ago.
  • Chlorine levels in the Antarctic stratosphere have fallen about 11 percent from the peak year in 2000. This year’s colder temperatures would have given us a much larger ozone hole if chlorine was still at levels we saw back in the year 2000.

    —Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center
According to NASA, the annual ozone hole reached an average area coverage of 8.83 million square miles (22.9 square kilometers) in 2018, almost three times the size of the contiguous United States. It ranks 13th largest out of 40 years of NASA satellite observations. Nations of the world began phasing out the use of ozone-depleting substances in 1987 under an international treaty known as the Montreal Protocol.

The 2018 ozone hole was strongly influenced by a stable and cold Antarctic vortex—the stratospheric low pressure system that flows clockwise in the atmosphere above Antarctica. These colder conditions—among the coldest since 1979—helped support formation of more polar stratospheric clouds, whose cloud particles activate ozone-destroying forms of chlorine and bromine compounds.

In 2016 and 2017, warmer temperatures in September limited the formation of polar stratospheric clouds and slowed the ozone hole’s growth. In 2017, the ozone hole reached a size of 7.6 million square miles (19.7 square kilometers) before starting to recover. In 2016, the hole grew to 8 million square miles (20.7 square kilometers).

However, the current ozone hole area is still large compared to the 1980s, when the depletion of the ozone layer above Antarctica was first detected. Atmospheric levels of man-made ozone-depleting substances increased up to the year 2000. Since then, they have slowly declined but remain high enough to produce significant ozone loss.

NOAA scientists said colder temperatures in 2018 allowed for near-complete elimination of ozone in a deep, 3.1-mile (5-kilometer) layer over the South Pole. This layer is where the active chemical depletion of ozone occurs on polar stratospheric clouds. The amount of ozone over the South Pole reached a minimum of 104 Dobson units on 12 Oct.—making it the 12th lowest year out of 33 years of NOAA ozone sonde measurements at the South Pole, according to NOAA scientist Bryan Johnson.
  • Even with this year’s optimum conditions, ozone loss was less severe in the upper altitude layers, which is what we would expect given the declining chlorine concentrations we’re seeing in the stratosphere.

    —Bryan Johnson. . . .

    Prior to the emergence of the Antarctic ozone hole in the 1970s, the average amount of ozone above the South Pole in September and October ranged from 250 to 350 Dobson units. . . .
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Oilpan4
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Mon Oct 05, 2020 9:19 am

Looks like 2020 is a record year for the size of the hole in the Ozone. It looks like banning CFCs wasn't the miracle cure it was advertised to be.

Remember the good old days when it was the hole in the Ozone that was supposed to kill us all?
Banning CFCs in inhalers and skyrocketing the price on them has killed way more people than the hole ever will.
"THE ABOVE POST CONTAINS MISLEADING AND INACCURATE INFORMATION. PLEASE CONSIDER IT OPINION, NOT FACT". -someone who I offended and is unable to produce the facts in question.

WetEV
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Mon Oct 05, 2020 10:48 am

Oilpan4 wrote:
Mon Oct 05, 2020 9:19 am
Looks like 2020 is a record year for the size of the hole in the Ozone. It looks like banning CFCs wasn't the miracle cure it was advertised to be.

Remember the good old days when it was the hole in the Ozone that was supposed to kill us all?
Banning CFCs in inhalers and skyrocketing the price on them has killed way more people than the hole ever will.
Really?

https://ozonewatch.gsfc.nasa.gov/
Image

CFCs are going to be around for centuries into the future. Ban just stops in increase, and starts a very very slow decrease.

https://www.ldeo.columbia.edu/~martins/ ... /cfcs.html
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Oilpan4
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Mon Oct 05, 2020 6:32 pm

Looks like the concentration is way below "normal" and the area uncovered is well above normal.
"THE ABOVE POST CONTAINS MISLEADING AND INACCURATE INFORMATION. PLEASE CONSIDER IT OPINION, NOT FACT". -someone who I offended and is unable to produce the facts in question.

WetEV
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Tue Oct 06, 2020 5:10 am

Oilpan4 wrote:
Mon Oct 05, 2020 6:32 pm
Looks like the concentration is way below "normal" and the area uncovered is well above normal.
The ozone will average below normal for many decades to several centuries as that is how long CFCs persist, and vary year to year based on weather.

So why does ozone loss due to CFCs vary with the weather?
WetEV
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Oilpan4
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Tue Oct 06, 2020 7:36 pm

Ozone is incredibly unstable.
"THE ABOVE POST CONTAINS MISLEADING AND INACCURATE INFORMATION. PLEASE CONSIDER IT OPINION, NOT FACT". -someone who I offended and is unable to produce the facts in question.

WetEV
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Wed Oct 07, 2020 7:38 am

Oilpan4 wrote:
Tue Oct 06, 2020 7:36 pm
Ozone is incredibly unstable.
A non answer. Ozone is reactive, but there wasn't much else to react with in the ozone layer. Before CFCs, that is.
WetEV
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goldbrick
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Wed Oct 07, 2020 10:50 am

My understanding is that ozone constantly decomposes to O2, the rate varies tremendously depending on temperature and other conditions. Ambient sunlight at the 'ozone layer' constantly generates ozone which constantly decomposes to 02. CFC's act as a catalyst for the O3 to O2 conversion which reduces the ozone half life which causes an ozone 'hole'.

Oilpan4
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Thu Oct 08, 2020 5:33 pm

Just it's own incredibly unstable self, everything else in the atmosphere and solar wind protons.
It's appearing more and more likely that the hole was always there.
"THE ABOVE POST CONTAINS MISLEADING AND INACCURATE INFORMATION. PLEASE CONSIDER IT OPINION, NOT FACT". -someone who I offended and is unable to produce the facts in question.

WetEV
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Re: GCC: NOAA, NASA: Ozone hole modest despite optimum conditions for ozone depletion

Thu Oct 08, 2020 8:10 pm

Oilpan4 wrote:
Thu Oct 08, 2020 5:33 pm
Just it's own incredibly unstable self, everything else in the atmosphere and solar wind protons.
It's appearing more and more likely that the hole was always there.
Incredibly unstable... So then the concentration drops to zero overnight? Right??

Solar wind has no impact on the lower stratosphere, where most of the ozone is.
WetEV
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