Ozone Hole Peak Approaches, But Falls Short Of Record

Ozone Hole Peak Approaches, But Falls Short Of Record

Greenbelt - Sep 26, 2003
This year's Antarctic ozone hole is the second largest ever observed, according to scientists from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Naval Research Laboratory.

The Antarctic ozone hole is defined as thinning of the ozone layer over the continent to levels significantly below pre-1979 levels. Ozone blocks harmful ultraviolet "B" rays. Loss of stratospheric ozone has been linked to skin cancer in humans and other adverse biological effects on plants and animals.

The size of this year's hole reached 10.9 million square miles on September 11, 2003. It was slightly larger than the North American continent, but smaller than the largest hole ever recorded, on September 10, 2000, when it covered 11.5 million square miles. Last year the ozone hole was smaller, covering 8.1 million square miles.

NASA's Earth Probe Total Ozone Mapping Spectrometer and the NOAA-16 Solar Backscatter Ultraviolet instrument provided ozone measurements from space. These data were coupled with data collected by NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL) from balloon-borne instruments, which measure the ozone hole's vertical structure.

NASA's own scientist Paul Newman said, "While chlorine and bromine chemicals cause the ozone hole, extremely cold temperatures, especially near the edge of Antarctica, are also key factors in ozone loss." (emphasis added)

Given the leveling or slowly declining atmospheric abundance of ozone-destroying gases, the year-to-year changes in the size and depth of the ozone hole are dominated by the year-to-year variations in temperature in this part of the atmosphere. The fact this year's ozone loss is much greater than last year's reflects the very different meteorological conditions between these two years.(emphasis added)

NASA scientist Rich McPeters said ozone observations showed the total amount of ozone from surface to space was 106 Dobson Units (DU) on September 14, 2003, the minimum value reached this year. "Dobson units" measure the "thickness" of protective ozone in the stratosphere. They range from 100 DU to 500 DU, which translate to about 1 millimeter (1/25 inch) to 5 millimeters (1/5 inch) of ozone in a layer.

Bryan Johnson of CMDL said the ozone depletion region, from 7-to-14 miles above the Earth, has large losses, similar to losses seen in the 1990s. If the stratospheric temperature remains cold over the pole, then we should see complete ozone loss in the 9-13 mile layer, with total column ozone reaching 100 DU by early October.

The Montreal Protocol and its amendments banned chlorine-containing chlorofluorocarbons (CFCs) and bromine-containing halons in 1995, because of their destructive effect on the ozone. However, CFCs and halons are extremely long-lived and still linger at high concentrations in the atmosphere. However, the atmospheric abundances of ozone destroying chemicals are beginning to decline. As a result, the Antarctic ozone hole should disappear in about 50 years. (emphasis added)

NASA's Earth Science Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System Science to improve prediction of climate, weather, and natural hazards using the unique vantage point of space.

Unfortunately, the ozone hole is now the largest on record and instead of shrinking, it persists.

Yesterday, UV penetration around here was obviously "striking."

It was so bright, that you could not see without sunglasses when outside and looking in any direction except away from the sun. Worst glare I've ever seen, and I had my G15's on.

I can't help but think that the leftists who rule environmentalism, and have been hell-bent upon blaming "corporate America" and the "usual suspect" chemicals (refrigerants) ... have overlooked something or a lot of things.

This link:

http://www.publicaffairs.noaa.gov/pr97/oct97/noaa97-60.html

Is an October 14, 2003 report of the ozone hole's recent expansion.

This NOAA page:

http://www.cmdl.noaa.gov/info/ozone_anim.html

... normally shows images of the hole, but they have stopped or blocked all such displays.

I hate to say it, but something is up, and I don't think that it's good news.

Here's that Oct. 14h report:

NOAA 97-60

Contact: Barbara McGehan FOR IMMEDIATE RELEASE Dave Hofmann 10/14/97 OZONE HOLE OVER SOUTH POLE EXPANDS

A complete loss of ozone between the altitudes of 14 and 20.5 km (9-13 miles) was observed recently by National Oceanic and Atmospheric Administration scientists at the South Pole. This is the broadest region and highest altitude in which complete ozone destruction has been observed during the Antarctic springtime ozone hole period to date.

According to David Hofmann, director of NOAA's Climate Monitoring and Diagnostics Laboratory in Boulder, Colo., this extension in altitude of total depletion is probably due to continued increases of stratospheric chlorine from human-induced CFCs (chlorofluorocarbons).

While chlorine-containing gases have begun to decline in the lower atmosphere due to restrictions placed on them by the Montreal Protocol and its subsequent amendments, it will take some time for chlorine to disappear from the stratosphere. (The Montreal Protocol is an international agreement to limit ozone-damaging compounds that was originally signed by the United States and 22 other nations in1987, and subsequently revised and amended.) However, the expectation is that chlorine levels in the upper atmosphere will peak near the turn of the century, resulting in the slow recovery of the ozone layer, Hofmann said.

Balloon soundings at the South Pole indicate that total column ozone reached a minimum of 112 Dobson units on Oct. 8. This is similar to what springtime minimum readings have been in the past few years, indicating that large changes in the magnitude of springtime Antarctic ozone depletion are not occurring. Dobson units are a measure of the thickness of the ozone layer, which has the ability to absorb ultraviolet light. Prior to the springtime period in Antarctica, when ozone depletion occurs, the normal Dobson unit reading is about 275-300.

Observations from instruments aboard a NOAA satellite indicate that the size of the Antarctic ozone "hole" approached 22 million square kilometers in early October. This is comparable to the recent size as observed by the NOAA-9 instrument in 1995 and 1996 at the same time of the season.

### Note to Editors: Balloonborne ozone profiles at the South Pole from the Climate Monitoring and Diagnostics Laboratory are available at: http://www.cmdl.noaa.gov/ozsondes/spo/ozppp.html

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