1. Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg 1871, Denmark
2. U.S. Geological Survey, Central Midwest Water Science Center, 400 South Clinton Street, Iowa City, Iowa 52240, United States
3. Department of Civil and Environmental Engineering and IIHR—Hydroscience and Engineering, University of Iowa, 4105 Seamans Center, Iowa City, Iowa 52242, United States
4. U.S. Geological Survey, Upper Midwest Water Science Center, 8505 Research Way, Middleton, Wisconsin 53562, United States