[1] Coop. Inst. Res. the Environ. Sci., University of Colorado, Boulder, CO, United States
[2] Institute of Arctic Biology, University of Alaska, Fairbanks, AK, United States
[3] Water and Environ. Research Center, University of Alaska, Fairbanks, AK, United States
[4] Global Change Research Group, San Diego State University, San Diego, CA, United States
[5] Department of Electrical Engineering, University of Michigan, Ann Arbor, MI, United States
[6] CIRES, Campus Box 216, University of Colorado, Boulder, CO 80309, United States