3/1/2010 - 2/28/2011
- Steven Loheide, UW-Madison
The objective of this study is to quantify the effect that climate change will have on the evapotranspiration (ET) component of the water budget in Wisconsin. The WICCI climate working group has already applied the best available science in downscaling GCM predictions of temperature and precipitation for the next century in Wisconsin. In comparison, we know very little about the extent to which the second largest component of the water budget, ET, will be affected by climate change effects such as increasing temperature, lengthening of the growing season, increased atmospheric carbon dioxide concentrations enhancing water use efficiency, changes in relative humidity, and changes in soil water availability. First, we will create a user-friendly interface that will predict ET using historic weather records and/or future climate scenarios, vegetation type and soil type. Second, we will parameterize detailed physiologic response functions for all major vegetation types in WI using available, and under-utilized, records of ET that are available at eddy covariance flux sites in the region. These flux towers are used primarily to measure carbon dioxide exchange across the land surface, but also record continuous measurements of water vapor exchange (ET) and are the best available ET records. Third, we will simulate the current and future ET for ecosystems in different regions of the state to characterize the general trends in ET that can be expected as a consequence of Wisconsin’s changing climate.