PARENT SESSION
Contributed Oral Session 157: Climate Dynamics: Temperature Effects; Modeling
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 516 D, Level 5, Palais des congrès de Montréal
Spatial patterns of trends in ice breakup dates for lakes across the Great Lakes Region in recent years.
Benson, Barbara*,1, Jensen, Olaf1, Magnuson, John1, Stewart, Kenton2, Card, Virginia3, Futter, Martyn4, Sorrano , Patricia5, 1 University of Wisconsin-Madison, Madison, Wisconsin2 State University of New York, Buffalo, New York3 Metropolitan State University, St. Paul, Minnesota4 Trent University, Peterborough, Ontario, Canada5 Michigan State University, East Lansing, Michigan
ABSTRACT- The timing of ice breakup in lakes is sensitive to climate change and variability. Evidence exists that climate warming has been occurring rapidly during the past thirty years (IPCC 2001). We examined spatial patterns of trends in ice breakup dates for 56 lakes across the Great Lakes region (Minnesota, Wisconsin, Michigan, Ontario, and New York) from 1971-2002. All 56 lakes showed a trend toward earlier ice breakup dates, with the average being 3 days earlier per decade. These recent trends in timing of ice breakup were more than an order of magnitude faster than those observed in the Great Lakes region from 1846-1995. Consistent with the trends toward earlier breakup, contours connecting locations at which breakup is predicted to occur on the same date shifted northward through the recent period. For example, the April 7th ice-off contour moved northward at approximately 100 km per decade. Temporal trends varied significantly over the study area, with a significant relationship between the trend and latitude and the latitude x longitude interaction. Trends toward earlier ice breakup were more rapid at more southerly latitudes and were strongest in the southeast and weakest in the northwest.
Key words: lake ice breakup, climate change, Great Lakes region, spatial pattern