This year, the South Pole region of Antarctica was slightly colder than the previous few years, so the ozone hole grew larger. However, scientists from NASA have developed models to predict what the ozone layer would have looked like without the Montreal Protocol, which banned the release of CFCs.
UN says Earth’s ozone layer is healing
by Seth Borenstein, AP
Earth’s protective ozone layer is finally healing from damage caused by aerosol sprays and coolants, a new United Nations report said.
The ozone layer had been thinning since the late 1970s. Scientist raised the alarm and ozone-depleting chemicals were phased out worldwide.
As a result, the upper ozone layer above the Northern Hemisphere should be completely repaired in the 2030s and the gaping Antarctic ozone hole should disappear in the 2060s, according to a scientific assessment released Monday at a conference in Quito, Ecuador. The Southern Hemisphere lags a bit and its ozone layer should be healed by mid-century.
“It’s really good news,” said report co-chairman Paul Newman, chief Earth scientist at NASA’s Goddard Space Flight Center. “If ozone-depleting substances had continued to increase, we would have seen huge effects. We stopped that.”
…
If nothing had been done to stop the thinning, the world would have destroyed two-thirds of its ozone layer by 2065, Newman said.
“I don’t think we can do a victory lap until 2060,” Newman said. “That will be for our grandchildren to do.”
Read more at: https://phys.org/news/2018-11-earth-ozone-layer.html#jCp
From NASA Goddard, it isn’t quite as rosy as Seth Borenstein makes it out to be, but still positive:
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 today.
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,” said Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “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.”
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 Oct. 12 — making it the 12th lowest year out of 33 years of NOAA ozonesonde 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,” Johnson said.
A Dobson unit is the standard measurement for the total amount of ozone in the atmosphere above a point on Earth’s surface, and it represents the number of ozone molecules required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 32 degrees Fahrenheit (0 degrees Celsius) at an atmospheric pressure equivalent to Earth’s surface. A value of 104 Dobson units would be a layer that is 1.04 millimeters thick at the surface, less than the thickness of a dime.
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.
What is ozone and why does it matter?
Ozone comprises three oxygen atoms and is highly reactive with other chemicals. In the stratosphere, roughly 7 to 25 miles (about 11 to 40 kilometers) above Earth’s surface, a layer of ozone acts like sunscreen, shielding the planet from ultraviolet radiation that can cause skin cancer and cataracts, suppress immune systems and damage plants. Ozone can also be created by photochemical reactions between the Sun and pollution from vehicle emissions and other sources, forming harmful smog in the lower atmosphere.
NASA and NOAA use three complementary instrumental methods to monitor the growth and breakup of the ozone hole each year. Satellite instruments like the Ozone Monitoring Instrument on NASA’s Aura satellite and the Ozone Mapping Profiler Suite on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite measure ozone across large areas from space. The Aura satellite’s Microwave Limb Sounder also measures certain chlorine-containing gases, providing estimates of total chlorine levels.
The total amount of ozone in the atmosphere is exceedingly small. All of the ozone in a column of the atmosphere extending from the ground to space would be 300 Dobson units, approximately the thickness of two pennies stacked one on top of the other.
NOAA scientists monitor the thickness of the ozone layer and its vertical distribution above the South Pole by regularly releasing weather balloons carrying ozone-measuring “sondes” up to 21 miles (~34 kilometers) in altitude, and with a ground-based instrument called a Dobson spectrophotometer.
To learn more about NOAA and NASA efforts to monitor ozone and ozone-depleting gases, visit:
https://ozonewatch.gsfc.nasa.gov/
https://www.esrl.noaa.gov/gmd/hats/
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For something to heal, it has to be sick. The ozone depletion in the stratosphere over Antarctica is natural, so it cannot be healed. The Montreal Protocol was extremely effective at making air conditioning more expensive, but has had little impact on stratospheric ozone, which ebbs and flows largely due to natural factors that have never been studied. The same is true for climate change in general.
It is far easier to appeal to the guilt of the Western World than to do science.
How on earth do heavy chlorine bearing molecules get high into the ozone generating altitudes? This is another model hoax but from Montreal, not UN IPCC. Ozone has fluctuated with temperature because of the kinetics of the reaction. The atmosphere is in climate change hiatus.
Diffusion and turbulent transport, that’s why the lower atmosphere is called the homosphere because the composition of the atmosphere doesn’t depend on Mol. wt below ~60 km.
Then why doesn’t the Ozone produced at ground level make it up to the stratosphere as a well-mixed gas ?.
This is where your own ideas are in contradiction. If the only way to get Ozone in the stratosphere is from solar radiation striking an axygen atom, rather than from turbulent transport and diffusion, then it must also be impossible for a chlorine molecule to make the same journey.
The difference between Ozone and CFCs is their chemical reactivity. CFCs are chemically inert, their lifetime is over one hundred years, consequently when emitted near the surface they have time to be distributed throughout the atmosphere (takes about 5 years). Ozone, on the other hand, is extremely reactive. Ozone is formed near the surface predominantly by photochemical reactions of the emissions from combustion processes, it usually peaks during summer afternoons. It is continually reacting with other species in the atmosphere so in the absence of sunlight it disappears. Consequently it doesn’t have time to spread through the atmosphere as a well-mixed gas. Up in the stratosphere ozone is predominantly created by the UV-photolysis of O2 (which can’t occur near the surface because the UV doesn’t reach that level). Due to the lack of other reactive species in the stratosphere O3 is sufficiently stable to form an ozone layer. If it is transported lower it will encounter reactive species with which it can react. CFCs which reach the stratosphere will encounter UV light and photolysis will produce Cl atoms there which will cause depletion of O3. This is worst in regions where Polar Stratospheric Clouds occur because of their catalytic effect on the destructive processes.
I still say that the ozone hole is just mother nature belching out all that excess CO2. I would love someone to go back and publish all those promises EPA made based on the USA getting rid of CFCs. Shouldn’t the hole be long closed?
If only the CFC causing ozone depletion was just limited to refrigerants. About 20 years ago the pharmaceutical albuterol inhalers for asthma (Ventolin, Proventil) lost their patents and generic versions came to market. These inhalers contained very small amounts of CFCs as propellants. Cynically, pharmaceutical manufacturers conspired and cooperated with environmental groups to get CFCs removed from inhalers by EPA edict. This removed inexpensive generic albuterol inhalers from the supply chain. In place of the generic inhaler the FDA approved three “brand only” albuterol inhalers – Proair, Proventil and Ventolin) that are “CFC free”. These have been patent protected for the past 20 years and cost 4 times the price of the old generic inhalers.
The patents are all expiring, but the FDA keeps denying generic applications. Each of these products has different, specialized formulations and delivery systems. American asthmatics have paid billions in unnecessary prescription costs due to bogus “save the ozone” regulations from the EPA.
The ozone hole story is a total fairy tale.
Like acid rain.
And the cooling scare.
And the warming scare.
And now the everything and nothing scare.
Man y years ago I said “Were their any two headed Penguins in Antarctica. It was also of interest that while the “Hole”was only in Antarctica”, not a problem, but then it was “Discovered in the North, Panic. Now its just another Green monster.
Snag is we are not only fighting nutty Greens, but big business as well.
MJE
Wasn’t the Ozone layer first discovered around 1918 and the first Ozone depleted area found in 1926?
I am truly baffled. In the almost six years during which I’ve been studying the matter, I’ve seen actual conditions in Earth’s atmosphere corroborate in great detail the conclusions I’ve reached, as detailed in: https://wattsupwiththat.com/2016/10/10/interesting-climate-sensitivity-analysis-do-variations-in-co2-actually-cause-global-significant-warming/ This research recently gained peer-reviewed status in the September issue of the Asian Academic Research Journal.
Despite the fact that my research has successfully predicted the behavior of Earth’s atmosphere resulting from the introduction of anthropogenic CFCs during the period 1975 to 1998, identifying this as the actual cause of global warming, and not CO2 at all, this research has received virtually no recognition by either the “warmist” or the “denier” camps. I can only assume that this is because both sides have it wrong, and they are both desperately intent on defending their flawed positions against all comers. Nonetheless, the ONLY model that correctly explains the behavior of Earth’s atmosphere since 1975 is mine, yet it isn’t even considered as anything other than idle speculation. I suppose this means that after 20 years or so of this prevarication, long after I’m dead and gone, climate scientists will finally converge on the unthinkable, that “by golly, David Laing got it right, after all! How about that?” Well, then, how about that?