1. Water and Environmental Research Center, University of Alaska Fairbanks, 1764 Tanana Loop, Fairbanks, AK 99775-5860, USA
2. College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 2150 Koyukuk Drive, Fairbanks, AK 99775-7220, USA
3. Joint Institute for the Study of Atmosphere and Ocean, University of Washington, 3737 Brooklyn Ave NE, Seattle, WA 98105