1. Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland College Park, 5825 University Research Court, College Park, Maryland 20740, United States
2. Cary Institute of Ecosystem Studies, Box AB, Route 44A Millbrook, New York 12545, United States
3. Department of Geography and Institute for the Environment, University of North Carolina Chapel Hill, Chapel Hill, North Carolina 27599, United States
4. Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, Pennsylvania 15260, United States
5. Bren School of Environmental Science and Management, University of California Santa Barbara, 2400 Bren Hall, Santa Barbara, California 93106-5131, United States
6. Water Resources Division, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, United States