The Sixth Xiamen Symposium on Marine Environmental Sciences

INT-01 SOLAS: Air-Sea interaction

Distribution and influencing factors of Net community productivity in the East China Sea and Yellow Sea in summer
Zhiguang Wu* , 1 Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; 2 Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
Chuan Qin, 1 Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; 2 Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
Lei Wang, 1 Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; 2 Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
Guiling Zhang, 1 Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; 2 Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China

The ocean is an important sink of atmospheric CO₂,which is vital to the alleviation of the global warming. Net community production (NCP), the difference between photosynthesis and respiration, can effectively reflect the strength of the biological pump, one of the main ways for oceanic uptake of CO₂. NCP can be estimated based on the dissolved oxygen to argon ratio(O₂/Ar) in the mixed layer. The shelf sea areas have high biological productivities with large spatial and temporal changes. In June 2018, we used the membrane inlet mass spectrometry (MIMS) system to obtain continuous O₂/Ar data in the East China Sea and the Yellow Sea and the NCP was also estimated. During the survey, the Δ(O₂/Ar) in the East China Sea was 0.050 ± 0.098, and the average of NCP was 20.77 ± 37.75 mmol C m^-² d^-¹ due to the low temperature, high salinity and high nutrients brought by the land source input in the East China Sea. The Δ(O₂/Ar) is 0.016 ± 0.066, and the average of NCP is 4.60 ± 33.18 mmol C m^-² d^-¹ in the Yellow Sea. The distribution of the NCP in Yellow Sea is mainly controlled by temperature, which makes the NCP in south higher than the NCP in north. Due to the impact of the Yangtze River discharge water, the maximum NCP of this survey was observed at the Yangtze River estuary, reaching 293.17mmol C m^-² d^-¹. Due to the influence of the cold upwelling in the East China Sea, the observed minimum value of -185.06mmol C m^-² d^-¹ appeared in the north side of the Yangtze River estuary. Phosphate and light intensity were the main factors controlling the distribution of NCP.