Yao Fu, South China Sea Institute of Oceanology, Chinese Academy of Sciences, State Key Laboratory of Tropical Oceanography, Guangzhou, China, Feili Li, Duke University, Durham, NC, United States, Chunzai Wang, State Key Laboratory of Tropical Oceanography, SCSIO, Chinese Academy of Sciences, Guangzhou, China, Johannes Karstensen, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany and N. Penny Holliday, National Oceanography Centre, Southampton, United Kingdom