An assessment of the utility of monitoring phenological changes in lake ice as an integrative indicator of regional climate change using the AVHRR
This research focused on the general hypothesis that satellite remote sensing of large-area, long-term trends in lake ice phenology (formation and breakup) is a robust, integrated measure of regional and global climate change. In order to confirm this hypothesis, I explored the use of data from the Advanced Very High Resolution Radiometer (AVHRR) to discriminate the presence and extent of lake ice during the winter of 1990- 1991 on the 45 lakes and reservoirs in the state of Wisconsin with a surface area of greater than 1,000 hectares. This study also addressed the relationship between lake ice seasonality and lake morphometry in the study area, and surprisingly found that the latter has very little effect on the former for the particular size of lakes studied. The results of this study suggest both the feasibility of using the A VHRR to determine the date of lake ice breakup, as well as the strong correlation (R = -0. 87) of the information so derived with local temperature - and thus the inherent desirability of utilizing archival satellite data to detect the climate change expected as a result of greenhouse warming.