Aquatic carbon fluxes from the conterminous US and Alaska

David E Butman, University of Washington Seattle Campus, School of Environmental and Forest Sciences, Seattle, United States, Sarah M Stackpoole, USGS Central Region Offices Denver, Denver, CO, United States, Edward Stets, U.S. Geological Survey, Water Mission Area, Mounds View, MN, United States, Cory McDonald, Department of Natural Resources Wisconsin, Madison, WI, United States, David W Clow, USGS Colorado Water Science Center Denver, Denver, CO, United States and Robert G Striegl, USGS Water Mission Area, Hydro-Ecological Interactions Branch, Boulder, United States