Inter Press Service
October 6, 1999, Wednesday
ENVIRONMENT:
A CLOSE-UP LOOK AT OZONE LAYER DEPLETION
by Marcela Valente
BUENOS AIRES, Oct. 6 - A Russian aircraft designed for espionage missions has become the centerpiece of a program uniting 80 scientists from around the world for an "in situ" study of atmospheric ozone depletion over the South Pole.
The month-long project calls for six flights of the M55 Geophysica aircraft, which is capable of flight in the stratosphere -- the layer above the atmosphere, more than 21,000 meters above the earth's surface.
The Geophysica measures 37 meters in length and reaches a velocity of 750 km per hour. It has a five-hour flight capability, even at critical temperatures, such as the 80 degrees below zero Celsius currently reported in the research area.
The most reliable studies of the ozone layer so far have been carried out over the Arctic Ocean and in Europe, using the same Geophysica, as well as the U.S. ER-2 aircraft of similar construction.
"The program objective is to study the chemical and physical processes responsible for thinning the ozone layer, which protects the biosphere from ultraviolet radiation," explained Ricardo Ozu, an engineer at Argentina's Antarctic Institute.
The mission is the first to be performed over the South Pole with an aircraft of this type. Until now, the evolution of the ozone layer has been followed from land using ozone-probing balloons and satellites. The phenomenon had never before been directly observed.
A Russian pilot flies the missions alone, while scientists work on land in Ushuaia, capital of Argentina's southernmost province, Tierra del Fuego. Another 17 research bases are also participating from both Antarctica and Punta Arenas in Chile.
The project known as APE-GAIA (Airborne Polar Experiment – Geophysica Aircraft in Antarctica), is coordinated by Bruno Carli of Italy, and is financed by the European Union in order to obtain better information about industrial development's impact on the ozone layer.
Other APE-GAIA scientists come from Argentina, Brazil, Bulgaria, Chile, Finland, Germany, Great Britain, Holland, Russia, Spain, Switzerland and the United States.
The research team chose this time of year to perform the study because measurements must be taken while the ozone layer is thinnest (August-September) and during the layer's recovery (October-November).
The layer of ozone gas, located 15 to 50 km above the earth's surface, filters the sun's ultraviolet radiation. A reduction in this natural defence increases the risk of skin cancer among humans, damages plant life and kills off the microscopic marine plankton essential to ocean ecosystems – and ultimately affects all ecosystems.
In the mid-1970s, scientists found evidence that the ozone layer was becoming thinner, and they reported that ozone loss continues at an annual rate of at least three percent, primarily as a result of industrial emissions of chlorofluorocarbons (CFCs) and halones.
The significantly reduced ozone levels over Antarctica, however, can be partially attributed to atmospheric currents over the region.
Atmospheric scientists report that wherever there is a high concentration of CFCs, ozone is reduced. There are natural processes that produce CFCs, but these are soluble and dissipate relatively quickly, while industrial CFCs are stable and long- lasting.
Computer models show that the ozone layer could return to its 1980 levels within 50 years, but only if the world stops all CFC emissions now, said Carli.
"This is something we will be able to confirm with the Geophysica flights," he added.
The project concludes this month with a report that will be presented to the Montreal Protocol on Substances that Deplete the Ozone Layer, which regulates the use of CFCs and halones to prevent further damage to the ozone layer.
The Protocol arose from an agreement signed in 1987 by a vast majority of nations from the industrialized North and the developing South, committing to reducing gas emissions. The agreement took effect in 1989.
The APE-GAIA project began research design in 1995 as a result of a scientific cooperation agreement between Italy and Russia, which later grew to include the participation of several academic institutions from other countries.
Research results will be known almost immediately because, as the aircraft records information, it sends the data to the various research bases, where it is collated with the data collected from land over the years.
