东、黄海典型海域叶绿素a含量的垂向变化与周日波动

VERTICAL CHARACTERISTICS AND DIEL VARIATION OF CHLOROPHYLL A IN THE TYPICAL AREAS OF EAST CHINA SEA AND SOUTHERN YELLOW SEA

2000年10月21至11月5日对东海与黄海典型海区进行了叶绿素a浓度的现场周日观测。地理环境和水文状况的差异使各海区的垂向变化与日波动表现出各自的特征 :东海观测站位在垂向上的分布比较单一 ,多数呈上混合层均匀分布型并在跃层以下递减 ;长江口受潮流影响大 ,偶而在底层出现峰值 ;而南黄海观测站位垂向分布出现了均匀分布型与次表层双峰型两种。受潮流等影响 ,叶绿素a浓度的日变化在各海区间及各自的垂向上都有所差异 :出现层化的测站 ,跃层以上日波动比跃层以下明显 ;在E7测站的表层和长江口测站的底层都以半日周期为主 ,而南黄海测站以全日周期为主。

The vertical distribution and diel variation of chlorophyll a concentration in the typical areas of East China Sea and Southern Yellow Sea were observed from October 21 to November 5, 2000. Due to the geographic environment and the hydrological conditions, there were marked characteristics of distribution and variation of chlorophyll a concentration. In the East China Sea, chlorophyll a concentration was well distributed in the mixed layer and decreased with the depth under the thermocline. Affected by the tidal currents, the maximum of chlorophyll a occasionally appeared at the bottom water in the Changjiang(Yangtze)River estuary. But in the surveyed area of Southern Yellow Sea, there existed two types of profiles of chlorophyll a distribution, namely, the well-distributed profile and the deep chlorophyll maximum profile. Accordingly, the diel variation of chlorophyll a showed more distinct in the mixed layer than under the thermocline in the stratified waters. In addition, the cycle of diel variation is half-day at the surface water of station E7 and at the bottom water of station E4 and is full-day in the stations of Southern Yellow Sea.