2006年夏季黄、东海溶解有机碳的分布特征

Distribution of Dissolved Organic Carbon in the Yellow Sea and the East China Sea in Summer,2006

用高温催化氧化法对黄、东海夏季溶解有机碳(DOC)进行测定,并对其平面分布特征进行分析。结果表明,2006年夏季黄、东海海域DOC质量浓度的变化范围为0.50～3.05mg/L,平均质量浓度为1.08mg/L。其平面分布表现为水深30m以浅海域呈现北高南低的特征,高值区主要集中在长江口以北的124°～126°E海域,该海域的DOC主要源自于生物体碎屑分解过程的释放;底层分布表现为由近岸向外海降低的趋势,且近岸高值主要来源于陆源排放和浮游植物的初级生产。垂直方向上,DOC平均质量浓度随深度增加逐渐降低,一方面由于上层水体浮游植物初级生产释放大量DOC,另一方面由于夏季海水层化使得较高质量浓度的DOC只能积累在较浅水域。

The dissolved Organic Carbon （DOC） in the Yellow Sea and the East China Sea in summer is de- termined by means of high temperature catalytic oxidation （HTCO） method and the horizontal distribution of DOC is studied. The results show that the concentration of DOC ranges from 0.50 to 3.05 mg/L in summer of 2006, with an average of 1.08 mg/L. Its horizontal distribution shows that the concentration of DOC is high in the north and low in the south in the area shallower than 30 meters, with the high values occurring mainly to the north of the Yangtze River Estuary and between 124°E and 126°E, where DOC comes mainly from the release of decomposition process of bioclastic. In the bottom layer the content of DOC tends to decrease from the nearshore to the offshore. The high values of DOC are mainly attributed to the discharge of land origin and the primary production of phytoplankton. Vertically, the average concen- tration of DOC decreases with the increase of water depth. The reason for this is that on one hand, the pri- mary production of phytoplankton releases large amount of DOC in the upper waters, and on the other hand, the water stratification in summer makes DOC accumulated only in the shallower waters.