- CSIRO, Bureau of Meteorology and British scientists are spending summer
studying the - self-cleansing - ability of the atmosphere. They are participating
in a major international project called the Southern Ocean Atmospheric
Photochemistry Experiment, based in north-western Tasmania.
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- Air contains naturally occurring chemicals
called hydroxyl radicals that react with, and destroy, a range of pollutants
and natural compounds.
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- "If levels of hydroxyl radicals
are changing, one consequence may be increasing concentrations of ozone
gas in the lower atmosphere," says Professor Stuart Penkett, from
the School of Environmental Sciences at the University of East Anglia in
the UK. Professor Penkett is a project leader for the experiment.
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- Ozone near the ground is both a greenhouse
gas and an irritant that attacks the throat and lungs and irritates the
eyes.
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- "A change in ozone and hydroxyl
radical concentrations in the lower atmosphere would certainly affect stability
of the world's climate," says Professor Penkett.
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- "Our Experiment is giving us a present-day
baseline in the cleanest air present in the atmosphere against which we
can check future changes. We will also use our results as a comparison
for similar studies in the more polluted northern hemisphere," says
Professor Penkett.
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- The Southern Ocean Atmospheric Photochemistry
Experiment is taking place now because sunlight is most intense at this
time of the year. The sun's energy plays a vital role in driving many of
the chemical reactions in the atmosphere.
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- The Experiment involves measurements
from the Cape Grim Baseline Air Pollution Station in Tasmania, from research
aircraft and from the CSIRO research vessel "Southern Surveyor"
Leeds University, Leicester University and the University of East Anglia
are working with CSIRO and Bureau of Meteorology scientists on the Experiment.
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- There will also be measurement flights
by a small pilotless aircraft. The 'aerosonde' will fly as high as three
kilometres, collecting data on atmospheric pressure, temperature, relative
humidity and wind speed. These data will be used in conjunction with observations
from the Cape Grim station of both atmospheric chemistry and meteorology.
-
- The Experiment involves approximately
50 scientists and engineers, PhD students and technical staff from CSIRO
Atmospheric Research and CSIRO Marine Research, from the Bureau of Meteorology,
and from the three British universities who are funded by the UK Natural
Environment Research Council.
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- The Southern Ocean Atmospheric Photochemistry
Experiment is one of the largest and most comprehensive studies ever conducted
into the chemistry of the lower atmosphere. It is part of a major international
effort being made to understand more about the chemistry of our atmosphere
and its impact on climate.
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- The Experiment will continue until 21
February, 1999.
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- Broadcast quality footage of the Cape
Grim Baseline Air Pollution Station, and the "Southern Surveyor"
research vessel is available on request.
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- More information: wendy.parsons@nap.csiro.au
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