SEASONAL AND INTER-ANNUAL VARIATIONS OF CHLOROPHYLL-a CONCENTRATION BASED ON THE REMOTE SENSING DATA IN THE YELLOW SEA AND EAST CHINA SEA
基于水色遥感的黄、东海叶绿素a浓度季节和年际变化特征分析

Inter-annual variability of chlorophyll-a concentration was significant in the Yellow Sea (YS) and the East China Sea (ECS). According to the geographical location, water depth and ecological characteristics, the YS and ECS were divided into five sub-regions. Seasonal variations of chlorophyll-a concentration indicated the phytoplankton bloom in these sub-regions occurred first in YS-coast, then subsequently in NYS-center, SYS-center, ECS-shelf, and finally in ECS-coast. Inter-annual variations of chlorophyll-aconcentration in four of the sub-regions were large, except in ECS-shelf. In winter and summer, the average chlorophyll-a concentration of the five sub-regions all reached the minimum values in 2008. In spring, the average chlorophyll-a concentration of the five sub-regions reached the maximum in 2006. In autumn, the values in 2009 were lower than in other years. The biomass in YS-coast was the highest, followed by in ECS-coast, in NYS-center, in SYS-center, and in ECS-shelf. The main factor affecting the inter-annual variation of phytoplankton was wind. In shallow coastal waters where nutrients were rich, low wind speed and increased stability of water column were favorable for the growth of phytoplankton. In deep open ocean waters, high speed wind brought nutrients to the surface and thus helped the growth of phytoplankton.