Xuan Li, Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China, Guangzhou, China, Xun Gong, Qilu University of Technology (Shandong Academy of Sciences), China, State Key Laboratory of Physical Oceanography, Institute of Oceanographic Instrumentation, Shandong Academy of Sciences, China;, Qingdao, China and Dongliang Yuan, First Institute of Oceanography, Qingdao, China