| 摘要: |
| 本文基于2015年7月长江口的现场调查资料,分析讨论了长江河口区溶解态铁(DFe)的含量分布与混合行为及其影响因素。结果表明:长江径流携带大量的DFe入海,且口内区(Ⅰ)浓度高于混合区(Ⅱ)和外海区(Ⅲ),平均浓度分别为166.45±6.26nmol/L,14.04±8.80nmol/L和6.18±1.51nmol/L。受去除作用和海水稀释的影响,在河口区DFe的浓度下降率达到96.92%。DFe浓度与盐度的关系符合指数模型,由模型与理论稀释线估算的长江口海域DFe的理论最大去除率为97.75%,与实际测得的最大浓度下降率相近。长江冲淡水、苏北沿岸流和台湾暖流影响DFe的水平分布。受长江冲淡水影响,长江口外海域DFe浓度高达176.50nmol/L。苏北沿岸流主要影响研究区域北部的表层水,其携带的DFe浓度低于长江冲淡水。台湾暖流是导致研究区域东南部DFe浓度较低的主要原因,使得中层和底层水中浓度分别低至4.04nmol/L和4.79nmol/L。另外,在表层海水中DFe的分布受到叶绿素a、溶解有机碳和溶解氧的共同影响,DFe与叶绿素a、溶解氧呈显著负相关,与溶解有机碳呈显著正相关。 |
| 关键词: 溶解态铁(DFe) 长江口 迁移 盐度 |
| DOI：10.11759/hykx20220322001 |
| 分类号:P734 |
| 基金项目:国家自然科学基金项目(41876079);国家海洋局海洋生态与环境科学与工程重点实验室开放基金资助项目(MESE-2018-05) |
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| Distribution and mixing behavior of dissolved iron in the Changjiang River Estuary during summer |
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WU Yao1, YAO Jia-jia1, YANG Ru-jun1, LIU Yuan1, ZHANG Ying-ying2
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1.College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China;2.Key Laboratory of Marine Ecology and Pollution Control for Environmental Protection in Jiangsu Provincial, College of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China
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| Abstract: |
| In this paper, the distribution and mixing behavior of dissolved iron (DFe) in the Changjiang River estuary and its influencing factors were analyzed and discussed based on the field investigation data of July 2015. The results showed that the Changjiang River carries a large amount of DFe into the East China Sea. The concentration of DFe in the mouth (I) area is higher than that in the mixed (II) area and the open sea (III) area, with average concentrations of 166.45±6.26 nmol/L, 14.04±8.80 nmol/L, and 6.18±1.51 nmol/L, respectively. However, affected by the removal of salinity and seawater dilution, the concentration reduction rate of DFe reached 96.92% in the estuary area. DFe concentration and salinity showed a significant negative correlation, which conforms to the exponential model. According to the model and theoretical dilution line, the theoretical maximum removal rate of DFe in the Changjiang River Estuary is 97.75%, which is identical to the actual reduction rate. The DFe distribution was affected by the Changjiang River diluted water, the Subei coastal current, and the Taiwan warm current. Influenced by the Changjiang River diluent water, the DFe concentration in the waters outside the Changjiang River mouth was as high as 176.50 nmol/L. The Subei coastal current mainly affected the surface water in the northern part of the study area, with a DFe concentration lower than that of the Changjiang River diluted water. The Taiwan warm current was the main reason for the low DFe concentration in the southeast of the study area and made the concentration in the middle and bottom water as low as 4.04 nmol/L and 4.79 nmol/L, respectively. In addition, the migration of DFe in surface seawater is affected by chlorophyll a, DOC, and DO. DFe was negatively correlated with chlorophyll a and DO but positively correlated with DOC. |
| Key words: dissolved iron (DFe) Changjiang River Estuary migration salinity |
