The 9th Chinese National Arctic Research Expedition （CHINARE 2018）

From July 20 to September 26, 2018, two teachers, Li Tao and Xing Lei from Ocean University of China, participated in the 69-day China's ninth Arctic scientific expedition. The expedition departed from Shanghai and entered the Arctic Ocean via the Sea of Japan, the Sea of Ojos, and the Bering Sea. 88 deep-physical oceanographic observations, including temperature and salt depth (CTD), flow velocity observations, were carried out in the high latitudes of the Arctic Ocean, the Canadian Basin, the Chukchi Sea, the Mendeleev Ridge, the Beaufort Sea and the Bering Sea. (LADCP) and Sound Velocity Observation (SVP), full-voyage voyage ocean surface hydrological observations. In addition, relying on the long-term and short-term ice station, Ocean University of China has deployed two sets of sea ice-air unmanned ice station type A prototype observation system, surface meteorological elements of sea ice, sea ice internal temperature gradient and sub-ice ocean temperature and salinity. Long-term continuous observation of depth, dissolved oxygen and chlorophyll, and the observation data is transmitted back to China for scientific research in real time. This system is the first hydrological-biochemical integrated long-term observation equipment deployed by China in the Arctic Ocean. It focuses on the hydrological and biochemical elements of the upper ocean during the winter night, and is used to reveal the interaction between sea ice and the upper ocean during the freezing of the Arctic Ocean. In order to understand the important role of summer melt pool in the process of sea ice melting from the perspective of thermodynamics, Li Tao et al. carried out optical observations of 16 pools in 7 short-term ice stations, including incident radiation, reflected radiation and transmitted radiation observation. Among them, the observation of the transmitted radiation inside the pool is the first practice of the Arctic scientific investigation in China. It is a method innovation of the sea ice optical attenuation coefficient observation, which helps to reveal the contribution of solar radiation to sea ice melting under different sea ice conditions. With the rapid decline of sea ice in the Arctic Ocean and the increase of open waters, the frequency of Arctic sea fog has increased significantly. The occurrence of sea fog has an important impact on the solar incident radiation received by sea ice, and at the same time brings potential risks to the navigation of ships. During the ninth Arctic scientific expedition in China, China Ocean University deployed a total of 41 sea fog visibility radiation profilers, and for the first time obtained the vertical distribution characteristics of solar short-wave radiation in the Arctic sea fog, providing a method for scientific research and applied research. And support on the data. (Li Tao)