厘清河口-陆架连续体的碳源/汇机制是认识海洋在“碳中和”中作用的重要基础。本研究基于2017年春季长江口-东海的走航CO2分压(pCO2)及温、盐等资料，分区域阐述春季长江口-东海连续体pCO2的空间分布格局，半定量解析水团分配、有机质生产及降解等过程对pCO2的控制作用。结果表明：水团来源是决定春季长江口-东海连续体pCO2分布及碳源/汇格局的主要因素，而有机质生产或者降解可强烈影响长江口-东海连续体碳源/汇格局。春季长江口门及浙江沿岸受长江径流影响而具有较高的pCO2，碳源强度可达5.36mmol·m-2·d-1；研究区域北部和东部分别受冲淡水及黑潮表层水的影响，表现为大气碳汇，北部碳汇强度为-15.44mmol·m-2·d-1。2017年春季研究区域平均碳通量为-6.73mmol·m-2·d-1。端元混合模型结果表明陆源有机质降解导致河口pCO2增加了约200μatm，促使春季河口由大气CO2的弱汇转变为碳源；陆架区域在仅考虑水团分配下同样为碳汇，而藻华过程进一步降低了pCO2(下降144μatm)，增强了其碳汇能力。

Controlling mechanism of air-sea carbon flux in estuary-shelf continuum is important for understanding the role of ocean in “carbon neutrality” goal of China. Based on underway sea surface partial pressure of CO2 (pCO2), temperature and salinity in the Changjiang (Yangtze River) Estuary-East China Sea in spring of 2017, the spatial variations of pCO2 in four domains of the Changjiang Estuary-East China Sea continuum were presented. The roles of water mass sources, organic matter production and decomposition in controlling pCO2 were discussed semi-quantitatively. The results indicated that water mass sources were key factors in determining pCO2 and air-sea carbon flux in the Changjiang Estuary-East China Sea continuum. In addition, production and decomposition of organic matters also influenced pCO2 significantly. Influenced by Changjiang discharge, surface waters in the inner Changjiang Estuary and Zhejiang coast had relatively high pCO2, served as source of CO2 to atmosphere, with magnitude of 5.36 mmol·m-2·d-1. The north and east of study area were influenced by the Changjiang Diluted Water, and Kuroshio Surface Water, respectively. While, they were both carbon sinks with magnitude of -15.44 mmol·m-2·d-1 in the north study area. The average air-sea carbon flux in study area in spring of 2017 was -6.73 mmol·m-2·d-1. End-member mixing model revealed that decomposition of organic matter increased pCO2 of the inner estuary by about 200 μatm, which transferred the inner estuary from carbon sink to carbon source in spring; the shelf waters were carbon sink if water mass sources were considered only, while biological production decreased pCO2(decreased 144 μatm) further, and enhanced the carbon sink.