Speaker: Dr. Richard Pe ltier\, Centre for Global Change Science\, University of Toronto
Abstract: During the past million years of Earth history\, climate variab
ility has been dominated by a 100 kyr cycle of continental scale glaciatio
n and deglaciation. Each of these quasi-periodic events owed its existence
to the minute variations in the distribution of solar radiation caused by
gravitational n-body effects in the solar system. In each cycle of this p
rocess continental glaciation was accompanied by a fall of mean sea level
of approximately 120 m. The glaciation phase of each cycle persisted for a
pproximately 90\,000 years whereas the deglaciation phase was much more ra
pid\, lasting approximately 10\,000 years. During deglaciation\, the retur
n of freshwater to the ocean basins was responsible for highly significant
disruptions of climate\, foremost among which was the so-called "\;Yo
unger-Dryas"\; climate reversal during which northern hemisphere surf
ace temperatures were forced to return to near full-glacial cold condition
s even as the system was in the process of returning to a state of modern
warmth. This phenomenon provides a
target for testing the transient re
sponse of the global climate models that are employed to make predictions
of the influence of global warming due to increasing concentrations of the
atmospheric greenhouse gases. This test will be described in detail.
Register for this seminar: https://www.sharcnet.ca/my /news/show_event/638
SUMMARY:Coast-to-Coast Seminar: Climate Impacts of Freshwater Forcing of th e Ocean General Circulation URL;VALUE=URI:http://www.sharcnet.ca/my/accessgrid/ END:VEVENT END:VCALENDAR