1. School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.
2. School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
3. Department of Earth Sciences, The University of Hong Kong, Hong Kong, China.
4. Department of Environmental Science, Baylor University, Waco, TX 76798, USA.
5. Division of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USA.
6. Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80521, USA.
7. Department of Atmospheric Science, Colorado State University, Fort Collins, CO 80523, USA.
8. Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, Switzerland.
9. Climate and Environmental Physics, University of Bern, 3012 Bern, Switzerland.
10. Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
11. British Antarctic Survey, Cambridge, UK.
12. Australian Antarctic Division and Antarctic Climate and Ecosystem Cooperative Research Centre, Hobart, Tasmania, Australia.
13. Clare Hall, University of Cambridge, Cambridge CB3 9AL, UK.