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Record-sized Ozone Hole over Canadian Arctic a Cause for Concern

Trent Alumnus delivers public lecture about ongoing ozone research

Dr. David Tarasick
Dr. David Tarasick

Dr. David Tarasick, Trent University Alumnus and senior research scientist with Environment Canada, delivered a public lecture sponsored by the department of Physics and Astronomy on the recent discovery of a record-sized hole in the ozone layer over the Canadian Arctic.

Dr. Tarasick was one of four Canadian authors of an international study published on October 2, 2011, in the British scientific journal Nature, revealing that chemical ozone destruction over the Arctic in early 2011 was—for the first time in the observational record—comparable to that in the Antarctic ozone hole. The newly discovered hole which formed over the Arctic in February and March of this year covers two million square kilometers - almost twice the size of Ontario. According to Dr. Tarasick, ozone loss over the Arctic has until now been variable, but much more limited than that over the Antarctic.

“While the ozone hole is cause for concern,” explained Dr. Tarasick, “it does not signal the same type of environmental crisis that the discovery of the Antarctic ozone hole did in the mid-1980s. It’s a health hazard, but a modest one. We have eliminated CFCs so chlorine in the atmosphere is going down. I would expect that while we may see more severe ozone holes for a while, they eventually will stop occurring. We really have already dealt with the problem.” Nonetheless, the discovery of the ozone hole over the Arctic is unexpected and was not predicted by scientific models, and therefore requires further study,” argued Dr. Tarasick.

Canada, whose ozone monitoring program has been described as “the backbone” of an international network, has played a pivotal role in ozone research over the years from the establishment of the world’s oldest ozone balloon-sounding station in the 1960s, to its leading role on the Montreal Protocol in 1987. In addition, it is a Canadian invention – the Brewer spectrophotometer – that is the international standard for ozone measurement, and the “Brewer triad” (a trio of Brewer spectrophotometers calibrated against one another to ensure accuracy, established by Environment Canada over 25 years ago) that is the reference for accurate calibration of Brewer spectrophotometers around the world, and for the global satellite record.

 Ozone research began in Canada in the 1930s, and ozone has been regularly monitored from the ground since the late 1950s, by balloon since 1966, and more recently by satellite. “It was fortunate that we had a long data set when people started to notice that the ozone was changing,” explained Dr. Tarasick. “Scientifically, the Arctic ozone hole is interesting because we didn’t expect it and we don’t understand it and we couldn’t predict it, so it does point to gaps in our understanding that we need to address.”

Dr. Tarasick holds an Honours B.Sc. in Physics and Mathematics from Trent University, a M.Sc. in Physics from l'Université de Montréal, and a Ph.D. in Physics from York University.

Posted on Wednesday, December 7, 2011.

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