1. Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama 236-0001, Japan.
2. Data Management and Engineering Department, Data Research Center for Marine-Earth Sciences, JAMSTEC, Yokohama 236-0001, Japan.
3. Department of Geophysics, Kyoto University, Kyoto 606-8502, Japan.
4. Environmental Satellite Applications, Llys Awel, Mount Street, Menai Bridge LL595BW, UK.