1. Department of Meteorology, University of Reading, Reading RG6 6BB, United Kingdom;
2. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA
3. Bolin Centre for Climate Research and Department of Geological Sciences, Stockholm University, 10691 Stockholm, Sweden
4. Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, 3584 CC Utrecht, The Netherlands
5. Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton SO14 3ZH, United Kingdom
6. Geophysical Institute, University of Bergen, 5020 Bergen, Norway
7. Bjerknes Centre for Climate Research, 5020 Bergen, Norway
8. Department of Geophysics, Tel Aviv University, 69978 Tel Aviv, Israel
9. Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA
10. Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
11. Department of Meteorology, Stockholm University, 10691 Stockholm, Sweden
12. California Institute of Technology, Pasadena, California 91125, USA
13. Department of Atmospheric Sciences, University of Washington, Seattle, Washington 98195, USA