长江口邻近海域溶解氧的时空分布及影响因素研究

基于2018年早春和夏季长江口邻近海域的调查数据,分析溶解氧(DO)的时空分布,并讨论其影响因素.结果表明,夏季DO浓度变化范围为1.58～9.37 mg/L,浮游生物光合作用产生的DO是夏季表层水体过饱和的主要因素;夏季调查海域受台湾暖流北上引起海水层化加强,同时水体富营养化导致表层生物大量繁殖所引起有机碎屑的沉降和...

Spatial-temporal distribution and dynamics of dissolved oxygen in an adjacent area of the Changjiang estuary

Using the direct survey data from early spring and summer in 2018, the spatial-temporal distribution and dynamics of dissolved oxygen (DO) in the Changjiang estuary were studied. In summer, the concentration of DO varied from 1.58 to 9.37 mg/L, and the DO produced by plankton photosynthesis played a dominant role in the supersaturation of the surface seawater. The low oxygen zone in the bottom layer was mainly attributed to the stratification generated by the northward movement of the Taiwan Warm Current (TWC), deposition of organic debris, and oxygen consumption caused by the mass proliferation of sea surface organisms due to eutrophication. There were positive correlations between apparent oxygen consumptions in the bottom seawater and nutrients under the influence of TWC. The degradation process of oxygen of bottom organic matter was closely related to nutrient regeneration. In early spring, DO was limited from 7.90 to 10.1 mg/L, and it was mainly controlled by temperature due to the vertical mixing of seawater in the northern area outside the Changjiang Estuary and the coastal area near Zhejiang province. However, stratification occurred in the area affected by TWC, and its low DO laid a foundation for the formation of a hypoxic zone.