Xiaogang Xing, Second Institute of Oceanography, State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou, China, Fei Chai, Second Institute of Oceanography, State Oceanic Administration, State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou, China, Yunwei Yan, Second Institute of Oceanography, China and Yuntao WANG, Second Institute of Oceanography State Oceanic Administration, Hangzhou, China