The ozone hole grew bigger this year

If you were a first-time visitor to WUWT, you'd never believe that Anthony Watts had been posting articles about climate and ozone for going on eight years. You'd think he was completely ignorant of all things science. And you'd be correct.

This false-color image shows ozone concentrations above Antarctica on Oct. 2, 2015. Credits: NASA/Goddard Space Flight Center

Today he's got an article about the ozone hole (cached here). It's a mite disturbing, especially for those of us who live in southern Australia. The ozone hole over Antarctica grew to be the fourth largest ever. That's because of the colder stratosphere. Stratosphere cooling arises from greenhouse warming, so as I understand it, this is partly because of our CO2 emissions.

As usual, Anthony didn't provide a link to the press release, but it's on the NASA website:

The 2015 Antarctic ozone hole area was larger and formed later than in recent years, said scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA).

On Oct. 2, 2015, the ozone hole expanded to its peak of 28.2 million square kilometers (10.9 million square miles), an area larger than the continent of North America.

Throughout October, the hole remained large and set many area daily records. Unusually cold temperature and weak dynamics in the Antarctic stratosphere this year resulted in this larger ozone hole. In comparison, last year the ozone hole peaked at 24.1 million square kilometers (9.3 million square miles) on Sept. 11, 2014. Compared to the 1991-2014 period, the 2015 ozone hole average area was the fourth largest.

“While the current ozone hole is larger than in recent years, the area occupied by this year’s hole is consistent with our understanding of ozone depletion chemistry and consistent with colder than average weather conditions in Earth’s stratosphere, which help drive ozone depletion,” said Paul A. Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The ozone hole is a severe depletion of the ozone layer above Antarctica that was first detected in the 1980s. The Antarctic ozone hole forms and expands during the Southern Hemisphere spring (August and September) because of the high levels of chemically active forms of chlorine and bromine in the stratosphere. These chlorine- and bromine-containing molecules are largely derived from man-made chemicals that steadily increased in Earth’s atmosphere up through the early 1990s.

“This year, our balloon-borne instruments measured nearly 100 percent ozone depletion in the layer above South Pole Station, Antarctica, that was 14 to 19 kilometers (9 to 12 miles) above Earth’s surface,” said Bryan Johnson, a researcher at NOAA’s Earth System Research Laboratory in Boulder, Colorado. “During September we typically see a rapid ozone decline, ending with about 95 percent depletion in that layer by October 1. This year the depletion held on an extra two weeks resulting in nearly 100 percent depletion by October 15."

The ozone layer helps shield Earth from potentially harmful ultraviolet radiation that can cause skin cancer, cataracts, and suppress immune systems, as well as damage plants. The large size of this year’s ozone hole will likely result in increases of harmful ultraviolet rays at Earth’s surface, particularly in Antarctica and the Southern Hemisphere in the coming months.

Ozone depletion is primarily caused by man-made compounds that release chlorine and bromine gases in the stratosphere. Beginning in 1987, the internationally agreed-upon Montreal Protocol on Substances that Deplete the Ozone Layer has regulated these ozone-depleting compounds, such as chlorine-containing chlorofluorocarbons used in refrigerants and bromine-containing halon gases used as fire suppressants. Because of the Protocol, atmospheric levels of these ozone depleting compounds are slowly declining. The ozone hole is expected to recover back to 1980 levels in approximately 2070.

This year, scientists recorded the minimum thickness of the ozone layer at 101 Dobson units on October 4, 2015, as compared to 250-350 Dobson units during the 1960s, before the Antarctic ozone hole occurred. Dobson units are a measure of the overhead amount of atmospheric ozone.

You can read the full press release at NASA.

When Anthony wrote the following he was probably oblivious to the irony (cached here, the archive pages are still broken):

A couple of days ago we ran a piece at WUWT: Did We Really Save the Ozone Layer? In light of this press release, the question is worth pondering again.

Anthony Watts is an ozone hole denier so his ponderings mean squat. No, we haven't yet "saved" the ozone layer, but we've achieved quite a bit. If only we could curb CO2 emissions, and it might help the hole recover more quickly. (As well as helping to mitigate global warming.)

From the WUWT comments

There are some classic denierisms in the "thoughts" at WUWT. Almost all WUWT readers are ozone science deniers as well as being climate science deniers. They can't help themselves. It's a conspiracy. Would Anthony Watts be game to post an article about evolution, or would he be too scared that the resulting comments would expose his nuttery more broadly? Meantime, you can try these ozone comments on for size:

Brant Ra might have had his brain molecules split in the ionosphere:

October 29, 2015 at 5:48 pm
The ozone hole is where the magnetospheric foot print touches down on the earth…. Changes in the local plasma sphere causes the footprint to grow wider. This makes the ozone hole bigger. But most importantly it lets more cold air from space down onto the surface of the earth… That shows up as the a colder polar vortex that moves to lower latitudes… Activity at the poles can be tied to density fluctuations in the solar wind.

markstoval confuses the troposphere with the stratosphere. It's the latter that was colder, consistent with greenhouse warming.

October 30, 2015 at 1:50 am
Could they not make up their minds? I was told global warming was a dead certainty. I was told it would warm at the poles first. Now it is way colder than “normal” at the South Pole?
The alarmists and logic are total strangers. 

From the HotWhopper archives

These three articles are probably the most comprehensive ones on ozone at HotWhopper - and they each have links to further reading:

• The ozone hole and the scientific illiterati @wattsupwiththat - December 2013
• WUWT goes from denying the ozone hole to blaming it for global warming! - August 2015 
• Denier weirdness: Paranoid conspiracy blog WUWT branches out into ozone hole denial - September 2014