Uncertainty and Variability of Wisconsin Lakes in Response to Climate Change

Background/Need: Many studies have shown that lake temperatures and ice cover can strongly affect water chemistry, individual organism physiology, population abundance, community structure, and food-web dynamics. Air temperature and wind speed are important factors driving these lake ecosystem properties. Understanding how lakes respond to changes in these drivers is of great interest to predict how lakes may change in the future. The response of lake ice and water temperature to long-term changes in air temperature and wind speed is integral to assess potential impacts of climate change on lake ecology.
Objectives: The purpose of this study is two-fold: first, to investigate how long-term changes in air temperature and wind speed affect the ice cover and thermal structures of a dimictic Lake Mendota, Wisconsin, USA over the past century; and second, to investigate the role of lake
morphometry in long term changes, variability, and sensitivity in response to increasing air temperatures and decreasing wind speeds in the Madison, WI area. We hypothesize that changes in lake ice cover and thermal structures on Lake Mendota may be characterized by periods of
abrupt changes rather than gradual trends based on observations of rapid change in the climate drivers of air temperature and wind speed. Our second hypothesis is that long term trends of changes in lake ice cover and thermal structure variables will be dependent on differences in lake
morphometry (i.e. lake depth and surface area).