海洋学研究 ›› 2021, Vol. 39 ›› Issue (4): 63-72.DOI: 10.3969/j.issn.1001-909X.2021.04.006

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2019年夏末长江口及其邻近海域走航pCO2变化及控制机制

  

  1. 1.自然资源部海洋生态系统动力学重点实验室,浙江 杭州 310012;
    2.自然资源部第二海洋研究所,浙江 杭州 310012
  • 出版日期:2021-12-15 发布日期:2022-01-25
  • 通讯作者: 于培松(1982-)，男，副研究员，主要从事近海碳的生物地球化学研究
  • 作者简介:杨旭锋(1989-)，男，河南省许昌县人，主要从事近海碳的生物地球化学研究,Email: yangxfzm@sio.org.cn。
  • 基金资助:
    中央级科研院所基本科研业务费专项资金资助项目(SZ2001,JT1502, JG1915)

Spatial variation of underway surface pCO2 and its controls in the Changjiang (Yangtze River) Estuary and adjacent sea area in late summer of 2019#br#
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  1. 1.Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources, Hangzhou 310012, China; 

    2.Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
  • Online:2021-12-15 Published:2022-01-25

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摘要： 利用2019年8月获得的长江口及其邻近海域表层海水pCO2的走航观测数据，结合温度、盐度、溶解氧等理化参数，初步探讨了该区域夏末表层海水pCO2的空间分布特点及控制因素。研究结果显示，整体上pCO2呈现近岸高而离岸低的特点，其中在长江冲淡水的中盐度区域出现了一个pCO2的极低值区。去除温度的影响，温度归一化后的pCO2与溶解氧饱和度具有良好的负相关关系，这表明生物过程是造成研究区域pCO2巨大空间差异的主要原因，其中高初级生产造成了中盐度区的强汇现象。同时河、海混合区断面的温度、盐度和溶解氧的分布显示水体层化致使垂直混合作用对pCO2的影响较小。整体而言，研究区域的海气界面CO2通量为-2.0±5.2 mmol·m-2·d-1，表现为大气CO2的汇。随着环境的改变和人为活动的干扰(如长江径流量的减少)，长江口及其邻近海域可能存在由大气CO2的汇转为源的风险，需要持续关注和研究。


关键词: 走航pCO2, 长江口, 控制机制, 夏末

Abstract: Base on underway surface CO2 data obtained from Changjiang (Yangtze River) Estuary and adjacent area in August 2019, combined with the temperature, salinity, dissolved oxygen and other parameters, the spatial variation of pCO2 and its controls during late summer were discussed briefly. The results show that the pCO2 generally decreases with distance offshore, and is the lowest in the mesohaline zone of river plume. After removing temperature effect, the good negative correlation between temperaturenormalized pCO2 and DO% indicates that biological processes are the main reason for the spatial variation, and the strong sink for atmospheric CO2 just results from high biological production. Moreover, the section distributions of temperature, salinity and DO% in the riverocean mixing zone show that the influence from vertical mixing on pCO2 is minor due to the water stratification. On the whole, the airsea CO2 fluxes for the study area are -2.0±5.2 mmol·m-2·d-1, showing a carbon sink with respect to atmospheric CO2. However, with environment changes and human perturbation such as the decrease of Changjiang runoff, Changjiang Estuary and its adjacent area may gradually shift from a sink to a source, which is necessary for us to pay more attention and further study.

Key words: underway pCO2, Changjiang (Yangtze River) Estuary, control mechanism, late summer

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