1. Department of Atmospheric Sciences and Institute of Geophysics and Planetary Physics; University of California, Los Angeles; Los Angeles California USA.
2. U.S. Geological Survey; San Diego California USA.
3. Department of Environmental Sciences; University of Virginia; Charlottesville Virginia USA.
4. Laboratoire des Sciences du Climat et de l'Environnement; UMR CEA-CNRS; Gif-sur-Yvette, France.