According to the conclusions of a new scientific study led by the American space agency, the ozone layer above the Arctic has grown extremely thin last winter. The finding surprised climate scientists, who have until now focused the bulk of their attention on the South Pole.
The depletion extended through spring, causing the characteristics of the upper stratosphere to change. Due to these phenomena, countries bordering Arctic regions suffered a prolonged winter, with the lowest temperature levels in years.
Details of the new investigation were published in the Sunday, October 2, issue of the top scientific journal Nature. The primary conclusion was that the Arctic lost just as much ozone as Antarctica did in some of its worst years.
The Southern Continent's ozone layer hole is the cause for the 1989 Montreal Protocol, which regulated the emissions of dangerous chemicals, including chlorofluorocarbons (CFC) such as freon. Even if further production is forbidden, existing chemicals have a lifespan of up to a century in the atmosphere.
The new investigation included researchers from the United States, Germany, the Netherlands, Canada, Russia, Finland, Denmark, Japan and Spain, from a total of 19 research institutions. Together, the experts investigated vast volumes of data, looking for causes and correlations.
Aura and CALIPSO spacecraft, both operated by
NASA, proved invaluable throughout the study, providing daily observations of the atmosphere, clouds, and gases. Scientific balloons and meteorological data augmented these results, as did atmospheric models.
“Day-to-day temperatures in the 2010-11 Arctic winter did not reach lower values than in previous cold Arctic winters,” NASA Jet Propulsion Laboratory (JPL) expert and lead study author Gloria Manney explains. She is also based at the New Mexico Institute of Mining and Technology, in Socorro.
“The difference from previous winters is that temperatures were low enough to produce ozone-destroying forms of chlorine for a much longer time,” she adds. JPL is a division of the California Institute of Technology (Caltech), in Pasadena.
“This implies that if winter Arctic stratospheric temperatures drop just slightly in the future, for example as a result of climate change, then severe Arctic ozone loss may occur more frequently,” she adds. In the stratosphere, cold temperatures lasted last winter up to 30 days longer than normal.
“Our ability to quantify polar ozone loss and associated processes will be reduced in the future when NASA's Aura and CALIPSO spacecraft, whose trace gas and cloud measurements were central to this study, reach the end of their operational lifetimes,” Manney concludes.
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