January 2, 2014
A study predicting snowfall changes in the Midwest is helping to better illustrate what winters could look like later this century.
Michael Notaro, associate director of the Nelson Institute Center for Climatic Research (CCR), is studying changes in overall snowfall and lake-effect snow throughout the upper Midwest. His research is producing important findings for a variety of groups interested in and impacted by these issues, from fellow scientists to land resource managers.
Michael Notaro
The first emphasis in Notaro's research – general changes in snowfall across the Midwest and Great Lakes region – was motivated by a need to better understand regional weather trends. Utilizing high-resolution climate projection data from fellow CCR climate scientist David Lorenz, Notaro has used a snow model that allows him to forecast how snowfall, snow depth and winter severity could change over the century.
The model projects a reduction in annual snowfall in the late 21st century by 24 percent (about 21 inches) for a low carbon emission scenario and 40 percent (about 35 inches) for a high carbon emission scenario. Yet total winter precipitation is expected to increase, with more rain as winters get warmer. And very heavy snowstorms in the region might also become more frequent, Notaro explains.
Notaro's study also predicts how lake-effect snow in the Great Lakes Basin will change in the future – an area currently lacking in study, he says. He uses a method called dynamical downscaling, where coarse global climate simulations are fed into a regional model to generate high-resolution climate projections.
This process allows for simulation of local weather and climate conditions in great detail: Notaro can zoom in to look directly at how temperature, ice cover and lake-effect snows are likely to change around the Great Lakes.
"Regional climate modeling is capable of simulating major storms and weather extremes, like lake-effect snowstorms, to a higher resolution and accuracy than a global model can," Notaro explains.
According to Notaro's findings, the whole Great Lakes basin will see a decrease in lake-effect snowstorms by the end of the century. An increase in temperatures might signal a switch to lake-effect freezing rain, creating unfavorable winter conditions and wetter, heavier snowpack – affecting snow removal, school closures, flight cancellations and traffic accidents.
From these snowfall projections, Notaro can also extrapolate how wildlife might respond. He is collaborating with the Michigan Department of Natural Resources and the Canadian organization Long Point Waterfowl to help translate what these climate changes could mean for deer and ducks, respectively.
Overall, less snow will mean more competition among species. Deer are more mobile with less snowpack and ducks are more likely to stay longer in the Midwest with milder conditions. A resulting increase in foraging pressures and demand for food would likely impact regional ecosystems.
Notaro's projections show other potential effects. For example, if spring snowfall decreases and temperatures rise, the snowmelt season will occur earlier in the year. Moisture that usually enters the soil late in spring will seep in earlier, and the soil could dry out by summertime – carrying the potential for summer drought conditions and implications for water availability.
The potential implications for both the economy and natural resources motivate Notaro to better understand these issues and pursue new scientific discoveries.
"It's very useful and exciting to see that when you're doing this work, it's not just academic; it's very important to managers in terms of understanding what's going to happen later this century," he says.
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