1. LGGE, UMR 5183; UJF-Grenoble 1/CNRS; Grenoble France
2. Now at Institute of Alpine and Arctic Research; University of Colorado Boulder; Boulder Colorado USA
3. Météo-France - CNRS; CNRM-GAME UMR 3589; CEN, Grenoble France
4. NOAA Earth Systems Research Laboratory; Boulder Colorado USA
5. Cooperative Institute for Research in Environmental Sciences; University of Colorado Boulder; Boulder Colorado USA
6. LTHE, UMR 5564; UJF-Grenoble 1/CNRS-INSU/G-INP/IRD; Grenoble France
7. NOAA Pacific Marine Environmental Laboratory; Seattle Washington USA