Katerina Dontsova, University of Arizona, Environmental Science Department, Biosphere 2, Tucson, AZ, United States, Malak M Tfaily, University of Arizona, Tucson, AZ, United States, Edward Hunt, University of Arizona, Biosphere 2, Tucson, AZ, United States, Rosalie Kae Chu, Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA, United States, Jason Toyoda, Pacific Northwest National Laboratory, EMSL, Richland, WA, United States, Jon Chorover, University of Arizona, Environmental Science, Tucson, AZ, United States and Peter A A Troch, University of Arizona, Hydrology and Atmospheric Sciences, Tucson, AZ, United States