[1] Univ Bern, Phys Inst, Climate & Environm Phys, Bern, Switzerland
[2] Univ Bern, Oeschger Ctr Climate Change Res, Bern, Switzerland
[3] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA
[4] Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ USA
[5] Sorbonne Univ, LOCEAN IPSL, Paris, France