1. Institute of Low Temperature Science Hokkaido University Sapporo Japan
2. Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA
3. National Institute of Polar Research Tachikawa Japan
4. Scripps Institution of Oceanography University of California, San Diego La Jolla CA USA
5. Institute for Geophysics University of Texas at Austin Austin TX USA
6. Atmosphere and Ocean Research Institute The University of Tokyo Kashiwa Japan