The distribution and emission of CO2, CH4 and light hydrocarbons in an anticyclonic eddy of the Kuroshio extension

Frontiers in Marine Science

Marine Science

Andrew Montgomery¹  Hao Qiao²  Hong-Hai Zhang²  Jian Wang²  Guang-Chao Zhuang²  Xiao-Jun Li²  Shan Zheng³  Rui-Chen Zhu⁴  Zhao-Hui Chen⁴ 

[1] Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, United States;Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Qingdao, China;Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China;College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, China;Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China;Jiaozhou Bay National Marine Ecosystem Research Station, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China;Physical Oceanography Laboratory, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, China;

关键词: mesoscale eddy;    Kuroshio and Oyashio Extension (KOE);    climate-relevant gases;    air-sea fluxes;    CO2;    methane;    non-methane hydrocarbons;   

DOI  :  10.3389/fmars.2023.1181896

 received in 2023-03-08, accepted in 2023-05-09,  发布年份 2023

来源: Frontiers

【 摘 要 】

Mesoscale eddies are energetic and swirling circulations that frequently occur in the open ocean. The effects of mesoscale eddies on the biogeochemical cycling of climate-relevant gases remain poorly constrained. We investigated the distribution and air-sea fluxes of CO2, methane, and five non–methane hydrocarbons (NMHCs) in an anticyclone eddy of Kuroshio Extension during September 2019. Within eddy core, intense stratification hindered the replenishment of nutrients and favored the growth of small-size phytoplankton, such as Prochlorococcus. Seawater pCO2 decreased from 406.1 μatm at the eddy outside to 377.5 μatm at the eddy core, accompanied by a decrease in surface seawater temperature from 26.7 °C to 25.2 °C. The vertical distribution of methane (0.3-9.9 nmol L-1) was influenced by the eddy process, with a maximum at 80 m in the eddy core, which might be attributed to the degradation of phosphonates sustained by Prochlorococcus. The concentrations of five NMHCs (ethane, ethylene, propane, propylene, and isoprene) ranged from 17.2-126.2, 36.7-168.1, 7.5-29.2, 22.6-64.1, 54.5-172.1, 3.5-27.9 pmol L-1, respectively. Isoprene correlated well with Chl-a concentrations at the eddy core, while no significant correlation was observed at the eddy outside. Air-sea fluxes of CO2 and isoprene associated with the eddy core were higher than those of the eddy outside, while the maximum ventilation of methane and other NMHCs (ethane, ethylene, propane, and propylene) was found at the eddy outside. Collectively, physical processes such as eddies impact the production and distribution of light hydrocarbons in seawater and further influence their regional emissions to the atmosphere.

【 授权许可】

Unknown   
Copyright © 2023 Li, Wang, Qiao, Zhu, Zhang, Chen, Montgomery, Zheng and Zhuang