夏季黄海和渤海微表层和次表层海水中营养盐的分布特征

基于2011年6月黄海和渤海微表层和次表层中营养盐(DIN、PO34--P、SiO23--Si)的调查数据,分析讨论了营养盐的平面分布特征,并选取黄海冷水团断面和长江口断面对营养盐的垂直分布特征进行了分析.结果表明,不论是微表层还是次表层,营养盐的分布都是从近岸向远海递减,在河口地区有明显的高浓度分布;由于夏季长江冲淡水左转北上,营养盐在黄海南部长江口区呈现出水舌状分布特征;受黄海冷水团的影响,北黄海冷水团断面的垂直分布出现表层层化和底层垂直混合均匀的现象;受长江径流输入的影响,长江口断面DIN和SiO23--Si的垂直分布呈现表层浓度大于底层浓度的特征.另外,研究了微表层对NH4+-N、NO2--N、NO3--N、PO34--P、SiO23--Si和DIN的富集情况,结果表明除NO3--N外,微表层对次表层中的其它营养盐都产生了明显的富集作用,平均富集因子介于1.37～2.21之间.

Distributional Characteristics of Nutrients in the Sea-surface Microlayer and Subsurface Water of the Bohai and Yellow Sea in Summer

The horizontal distributional characteristics of nutrients (DIN, PO₄^3--P, SiO₃^2--Si)were studied in the sea-surface microlayer (SML) and subsurface water of the Bohai and Yellow Sea in June 2011, and the vertical distributions of nutrients in the transects of the Yellow Sea Cold Water Mass and the north of the Changjiang River estuary were also investigated. The results showed that the nutrient concentrations in the sea-surface microlayer and subsurface water decreased gradually from inshore to offshore, and higher values were observed in the Changjiang River estuary. A tongue-shaped distribution was observed in the south of the Yellow Sea as a result of the Changjiang diluted water. Stratification occurred in the surface layer and vertical mixing characteristics were observed in the bottom due to the influence of the Yellow Sea Cold Water Mass. In the vertical distributions, higher concentrations of DIN and SiO₃^2--Si in the north of the Changjiang River estuary occurred in the sea surface compared with the bottom due to the Changjiang River diluted water. The enrichment results of NH₄⁺-N, NO₂^--N, NO₃^--N, PO₄^3--P, SiO₃^2--Si and DIN showed that the sea-surface microlayer displayed an apparent enrichment for nutrients except NO₃^--N, and the mean enrichment factors ranged from 1.37 to 2.21.