1. Physics Department; University of Santiago de Chile; Santiago Chile
2. Now at Japan Agency for Marine-Earth Science and Technology; Yokohama Japan
3. Instituto de Astrofísica de Andalucía, CSIC; Granada Spain
4. Institute for Meteorology and Climate Research; Karlsruhe Institute of Technology; Karlsruhe Germany
5. Jet Propulsion Laboratory; California Institute of Technology; Pasadena California USA