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 Turning the Climate Tide by 2020
29.06.2017 | Potsdam-Institut für Klimafolgenforschung

nachricht Predicting eruptions using satellites and math
28.06.2017 | Frontiers

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making Waves

Computer scientists use wave packet theory to develop realistic, detailed water wave simulations in real time. Their results will be presented at this year’s SIGGRAPH conference.

Think about the last time you were at a lake, river, or the ocean. Remember the ripples of the water, the waves crashing against the rocks, the wake following...

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Nanostructures taste the rainbow

29.06.2017 | Physics and Astronomy

New technique unveils 'matrix' inside tissues and tumors

29.06.2017 | Life Sciences

Cystic fibrosis alters the structure of mucus in airways

29.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>