Melbourne - November 19, 1999 - Scientists can now measure ozone depleting gases hundreds of kilometres from where they are released. Using instruments so sensitive that they will detect just a few kilograms per day of a gas released from a distant city, researchers have begun monitoring urban emissions of a variety of ozone depleting and greenhouse gases.
Releases from the city of Melbourne in Victoria are being detected some 12 hours later at Cape Grim in remote north-western Tasmania, across three hundred kilometres of the Bass Strait.
Michelle Cox and Bronwyn Dunse, PhD students at CSIRO Atmospheric Research, have tracked releases of CFCs, HCFCs and HFCs from Melbourne.
HCFCs and HFCs are refrigerants, developed as short-term and long-term replacement chemicals, respectively, for ozone-depleting CFCs.
When the wind blows from Melbourne, the gas chromatographs at Cape Grim measure concentrations of a range of pollutants from the city. The students are using these measurements to calculate how much CFCs, HCFCs and HFCs are emanating from Melbourne.
"We have been able to provide industry with estimates of refrigerant releases from Melbourne," says Ms Cox.
"Remote measurement of gaseous releases also offers potential for monitoring Australia's emissions of greenhouse gases," says Ms Cox.
"My next step will be to check emissions from the mainland of methyl bromide, a fumigant used to kill insects in grains and pests in soils," says Ms Cox.
There are restrictions on the use of methyl bromide because it is an ozone depleting chemical.
Ms Cox is a student at the Co-operative Research Centre for Meteorology at Monash University; Ms Dunse is enrolled at the Chemistry Department of Wollongong University. Refrigerant Reclaim Australia are partially funding the students' research.
The two students rely on wind and weather data supplied by the Bureau of Meteorology. They also use CSIRO's latest high-resolution air pollution model, known as TAPM, to track where emissions detected at Cape Grim have originated.
The Cape Grim program to monitor and study global atmospheric composition is a joint responsibility of the Bureau of Meteorology and CSIRO.
Ms Cox and Ms Dunse are supervised at CSIRO Atmospheric Research by Drs Paul Fraser and Paul Steele.
An image and an animation showing a pollution plume crossing Bass Strait are available on request.
TERRADAILY.COM
Searching For Ozone In The Winter Dark
Washington - November 18, 1999 - NASA scientists are joining researchers from Europe, Russia, Canada and Japan to mount the largest field-measurement campaign ever to assess ozone amounts and changes in the Arctic upper atmosphere this winter. This collaborative campaign will measure ozone and other atmospheric gases using satellites, airplanes, heavy-lift and small balloons, and ground-based instruments. From November 1999 through March 2000, researchers will examine the processes that control ozone amounts during the Arctic winter at mid to high latitudes.