Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unusually small antarctic ozone hole this year attributed to exceptionally strong stratospheric weather systems

01.10.2002


Scientists from NASA and the Commerce Department’s National Oceanic and Atmospheric Administration (NOAA) have confirmed the ozone hole over the Antarctic this September is not only much smaller than it was in 2000 and 2001, but has split into two separate "holes."

The researchers stressed the smaller hole is due to this year’s peculiar stratospheric weather patterns and that a single year’s unusual pattern does not make a long-term trend. Moreover, they said, the data are not conclusive that the ozone layer is recovering.

Paul Newman, a lead ozone researcher at NASA’s Goddard Space Flight Center, Greenbelt, Md., said this year, warmer-than-normal temperatures around the edge of the polar vortex that forms annually in the stratosphere over Antarctica are responsible for the smaller ozone loss.



Estimates for the last two weeks of the size of the Antarctic Ozone Hole (the region with total column ozone below 220 Dobson Units), from the NASA Earth Probe Total Ozone Mapping Spectrometer (EPTOMS) and the NOAA-16 Solar Backscatter Ultraviolet instrument (SBUV/2), are around 15 million square kilometers (6 million square miles). These values are well below the more-than 24 million sq. km. (9 million sq. mi.) seen the last six years for the same time of year.

The stratosphere is a portion of the atmosphere about 6-to-30 miles above the Earth’s surface where the ozone layer is found. The ozone layer prevents the sun’s harmful ultraviolet radiation from reaching the Earth’s surface. Ultraviolet radiation is a primary cause of skin cancer. Without protective upper-level ozone, there would be no life on Earth.

"The Southern Hemisphere’s stratosphere was unusually disturbed this year," said Craig Long, meteorologist at NOAA’s Climate Prediction Center (CPC). The unusual weather patterns were so strong, the ozone hole split into two pieces during late September. NOAA’s CPC has been monitoring and studying the ozone since the early 1970s. "This is the first time we’ve seen the polar vortex split in September," said Long.

At South Pole Station, balloon-borne ozone-measuring instruments launched by NOAA’s Climate Monitoring and Diagnostics Laboratory (CMDL) reveal the vertical structure of the developing ozone hole. Bryan Johnson, a scientist with CMDL, said the main ozone depletion region, from 7-to-14 miles above the Earth, has large ozone losses, similar to the last few years. At more than 15 miles above the Earth, surface measurements show higher-than-normal ozone concentrations and higher temperatures.

The combination of these layers indicate total ozone levels in a column of atmosphere will be higher than observed during the last few years, Johnson said. However, some layers may still show complete ozone destruction by early October, when ozone depletion is greatest.

In 2001, the Antarctic ozone hole was larger than the combined area of the United States, Canada and Mexico. The last time the ozone hole was this small was in 1988, and that was also due to warm atmospheric temperatures.

"While chlorine and bromine chemicals cause the ozone hole, temperature is also a key factor in ozone loss," Newman said. 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 layer. However, CFCs and halons are extremely long-lived and still linger at high concentrations in the atmosphere.

The coldest temperatures over the South Pole typically occur in August and September. Thin clouds form in these cold conditions, and chemical reactions on the cloud particles help chlorine and bromine gases to rapidly destroy ozone. By early October, temperatures usually begin to warm, and thereafter the ozone layer starts to recover.

NOAA and NASA continuously observe Antarctic ozone with a combination of ground, balloon, and satellite-based instruments.

Rob Gutro | EurekAlert!
Further information:
http://www.gsfc.nasa.gov/gsfc/earth/pictures/20020926ozonehole/2002ozonehole.mov

More articles from Earth Sciences:

nachricht New research calculates capacity of North American forests to sequester carbon
16.07.2018 | University of California - Santa Cruz

nachricht Scientists discover Earth's youngest banded iron formation in western China
12.07.2018 | University of Alberta

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>