1. Climate Change Institute and School of Earth and Climate Sciences University of Maine Orono ME USA
2. Department of Earth Sciences Dartmouth College Hanover NH USA
3. Department of Chemistry and Biochemistry South Dakota State University Brookings SD USA
4. Department of Atmospheric Sciences University of Washington Seattle WA USA
5. Department of Earth and Space Sciences University of Washington Seattle WA USA
6. Institute of Arctic and Alpine Research University of Colorado Boulder CO USA