1. Polar Environmental Research and Forecasting Division; National Marine Environmental Forecasting Center; Beijing China
2. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research; Bremerhaven Germany
3. Institute of Oceanography, University of Hamburg; Hamburg Germany
4. Department of Atmospheric and Environmental Sciences; University at Albany, State University of New York; Albany New York USA
5. Key Laboratory for Polar Science of the State Oceanic Administration; Polar Research Institute of China; Shanghai China