| 摘要: |
| 本文基于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1.58-9.37mg/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现象，及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耗氧分解作用是底层低氧区存在的的主要因素。夏季在台湾暖流影响下底层水体表观耗氧量（AOU）与营养盐（NO3--N、PO43--P、SiO32--Si ）成显著正相关，相关系数分别为0.91、0.86和0.93，底层有机物耗氧降解过程与营养盐的再生密切相关。夏季DO与PH呈显著正相关，底层缺氧会引起水体酸化现象。冬季由于水体垂直混合均匀，DO整体上呈现饱和状态，冬季DO浓度变化范围为7.90-10.12mg/L，DO的空间分布主要受温度和盐度控制。 |
| 关键词: 溶解氧 长江口 表观耗氧量 低氧区 |
| DOI： |
| 分类号: |
| 基金项目:国家杰出青年科学基金 |
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| The Spatial-temporal Distribution and Dynamics of Dissolved Oxygen in the Adjacent Area of the Yangtze Estuary. |
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sunyi, weichuanjie, wangyanqing, panjun, diaoxinyuan
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Institute of Oceanology, Chinese Academy of Sciences
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| Abstract: |
| Utilized with the direct survey data in early spring and summer of 2018, the spatial-temporal distribution and dynamics of dissolved oxygen (DO) are discussed near the Yangtze Estuary. In summer, the concentration of DO is limited in 1.58-9.37mg/L, and the DO from plankton photosynthesis plays a dominant role in the supersaturation of the surface seawater. The low oxygen zone in the bottom layer is mainly attributed to the stratification generated by the northward movement of the Taiwan Warm Current (TWC), and the deposition of organic debris and the decomposition of oxygen consumption caused by mass proliferation of sea-surface organisms due to eutrophication. Significantly positive correlations occur between the apparent oxygen consumption (AOU) of the bottom seawater and the nutrients (NO3--N, PO43--P, SiO32--Si) with the correlation coefficient of 0.91, 0.86 and 0.93 under the influence of Taiwan Warm Current. The degradation process of oxygen consumption of bottom organic matter is closely related to the regeneration of nutrients. DO keeps the positive correlation with pH, and hypoxia zone at the bottom leads to the acidification of the seawater. In early spring, due to the vertical mixing of seawater, DO is saturated as a whole and limited in 7.90-10.12mg/L. In general, the spatial distribution and variability of DO are mainly controlled by temperature and salinity. |
| Key words: dissolved oxygen Yangtze Estuary apparent oxygen consumption hypoxia zone |