TORONTO, November 23, 2007 -- York University will host its 17th annual Harold I. Schiff lecture on Nov. 27, featuring professor Paul B. Shepson, an expert on Arctic climate change.
Shepson is Director of the Purdue Climate Change Research Center at Purdue University, and an adjunct professor of chemistry in York’s Faculty of Science and Engineering
The lecture will take place at 2:30 pm in the Senate Chamber, Ross Building, on York’s Keele Campus.
Shepson’s lecture, “Climate Change, and Atmosphere-Surface Interactions in the Arctic,” will examine the impact of climate change on Arctic sea ice, snow pack, permafrost and plant and animal life. Shepson will discuss current research activities of the international project Ocean-Atmosphere-Sea Ice-Snowpack (OASIS).
As part of OASIS, Shepson is studying how climate change alters the way air pollutants such as mercury are removed from the atmosphere. Each spring brings an interplay between the sun, ozone and sea salt on the frozen ocean, which causes bromine and other halogens to be released into the atmosphere. These in turn destroy lower-atmospheric ozone and mercury. However, a depletion of sea ice due to climate change is altering these atmospheric processes.
“Eventually, when the sea ice is gone, this process of mercury and ozone depletion will stop, but in the meantime there is more first year ice on the Arctic Ocean. So for a few decades these processes may increase leading to input of more mercury into the ocean and surrounding ecosystems,” says Shepson.
As the sea ice retreats, the reflectivity of the surface also decreases causing sunlight to be absorbed rather than reflected.
“That leads to faster warming, which leads to faster sea ice retreat, and so on,” says Shepson. This could have a major impact on native Arctic peoples and surrounding plant and animal life.
In the spring of 2008, Shepson will participate in the International Polar Year project, OASIS-CANADA, to conduct further atmospheric chemistry research in the Arctic.
The Harold I. Schiff Lecture was established in 1990 to honour Harold I. Schiff, founding dean of York’s Faculty of Science. Schiff is well-known in the scientific community for this development of techniques for measuring trace constituents in the upper atmosphere, and his interpretation of the physics and chemistry of the stratosphere.
The lecture is organized by the York University Centre for Atmospheric Chemistry. For more information, e-mail cac@yorku.ca .
What: The 17th Annual Harold I. Schiff Lecture
When: Nov. 27, 2007, 2:30 pm
Where: Senate Chamber, N940, Ross Building, on York University’s Keele Campus
Media contact:
Melissa Hughes, Media Relations, York University: 416 736 2100 x22097 / mehughes@yorku.ca
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