2013年夏季黄、渤海颗粒有机碳分布及来源分析

Distribution and source analyses of particulate organic carbon in the Yellow Sea and Bohai Sea during summer,2013

本文根据2013年夏季黄、渤海海域航次获得的颗粒有机碳（particulate organic carbon,POC）、叶绿素a（chlorophyll a,Chl a）和总悬浮颗粒物（total suspended particles,TSP）数据,结合同步获得的水文环境参数,综合探讨该区夏季POC时空分布特征,以及在不同温盐深水团中POC的主要影响因素。结果表明：在整个研究区POC的浓度范围为102.3～1 850.0μg/L,平均值为（383.7±269.6）μg/L,分布呈现出近岸高、远海低、表层低、底层高的特征。苏北外浅滩海域和北黄海东北区域的10m层和底层为POC高值区,苏北外海域受到陆源输入、沿岸流混合作用和浮游植物光合作用的影响,POC上下混合均匀且浓度高;南黄海中部因受黄海环流的影响,水体中浮游植物生产力水平低,POC浓度较低。在垂直分布上,近岸海域受陆源输入和再悬浮影响POC浓度高,上下混合均匀;在南黄海和北黄海中部受到黄海环流和黄海冷水团的控制,浮游植物生产力水平低,POC浓度低。对不同温盐水团中POC的影响因素分析发现,在高温低盐水团中,POC受浮游植物初级生产和陆源输入的共同影响;在温盐适中区真光层海水中,浮游植物的初级生产是POC的主要来源;底层的冷水团区,POC主要来源为上层海水中颗粒物的沉降和底层再悬浮作用。

Based on the data of particulate organic carbon（POC）,chlorophyll a（Chl a）and total suspended particles（TSP）as well as hydrological environment parameters collected during the summer of 2013 in the Yellow Sea and Bohai Sea.We examined the spatial and temporal distribution patterns of POC,and possible factors influencing POC contents and distributions in various water masses characterized by temperature and salinity.Results show that POC concentrations ranged from 102.3μg/L to 1 850.0μg/L,with an average of（383.7±269.6）μg/L,and declined from nearshore to offshore areas but increased from surface to bottom layers.The high concentration of POC appears at northern of Jiangsu Province because of the runoff input,mixing effect of longshore currents and enriched phytoplankton photosynthesis,and at the layers of both 10 mand bottom in the northeast area of the northern Yellow Sea.Influenced by ocean circulations,phytoplankton productivity was relatively lower in the middle of the southern Yellow Sea,and resulted in the lower POC concentrations in this regional area.Vertical distribution shows that POC concentrations were higher and mixed well in the nearshore area because of terrestrial input and resuspension.Controlled by ocean circulation and the Cold Water Mass,phytoplankton productivity was relatively lower in the middle of southern and northern Yellow Sea,and correspondingly decreased POC concentrations.In the water masses characterized by high temperature and low salinity,POC distributions were mainly influenced by phytoplankton primary production and resuspension.In the water masses characterized by moderate temperature and salinity,primary production of phytoplankton was the major source of POC.In the cold water mass of bottom layers,the main sources of POC were particle deposition and resuspension.