Analysis of Chlorophyll Concentration during the Phytoplankton Spring Bloom in the Yellow Sea Based on the MODIS Data

摘要

The Yellow Sea is semi-enclosed shelf sea located between the mainland of China and the Korea Peninsula. It is one of the most important fishing areas in the world. Phytoplankton bloom is defined as a relatively rapid increase in the biomass of phytoplankton. The twice bloom in spring and autumn every year is common in Yellow Sea. Chlorophyll concentration is the important parameters to estimate the phytoplankton biomass and its seasonal variation or blooms. Taking the yellow sea as an experimental site, a cruise for phytoplankton bloom was carried out in the Yellow Sea with R/V Beidou founded by 973 projects. Chlorophyll was measured by a fluorescence sensor of sea point installed on a RBR 620 CTD. Using MODIS remote sensing images, unifying the location water quality monitor data, in this paper the model of retrieval of chlorophyll concentration is built using the 250m resolution waveband 1 and 2 reflectivity combination compare with chlorophyll concentration measurements by correlation analysis and multivariate regression. Then, the distribution of chlorophyll concentration in the yellow sea is mapped based on this retrieval model. The intensity, place, process and distributed scope of this phytoplankton spring bloom reflected clearly. The results of this study show that MODIS data is useful in retrieving quantitatively chlorophyll concentration and studying on the onset of phytoplankton spring bloom and its dynamics in the yellow sea.