1. College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.
2. Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Denmark.
3. Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
4. Scripps Institution of Oceanography, University of California–San Diego, La Jolla, CA 92093, USA.
5. Center for Climatic Research, Nelson Institute for Environmental Studies, University of Wisconsin, Madison, WI 53706, USA.
6. Department of Physics and Physical Oceanography, Memorial University, St. John’s, Canada.
7. Division of Climate and Environmental Physics, Physics Institute and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland.
8. Laboratoire des Sciences du Climat et de l’Environnement, Institut Pierre Simon Laplace (UMR CEA-CNRS-UVSQ 8212), Gif-sur-Yvette, France.
9. Laboratory for Climate and Ocean-Atmosphere Studies, Peking University, Beijing 100871, China.
10. Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO 80307, USA.