东海原甲藻垂直迁移对水体反射光谱的影响及其遥感应用

Reflectance spectra of red tide water are the foundation of satellite remote sensing of red tide. This study focuses on the impacts of vertical migration of Prorocentrum donghaiense on red tide reflectance spectra measured in field observation experiments combined with ocean reflectance spectra numerical simulation method. Using the vertical distribution information of algal cell concentration obtained through field observations, nonuniform vertical profiles of chlorophyll concentrations will be established to represent for the different vertical migration stages of P. donghaiense. An ocean reflectance spectra model suitable for the optical complex waters (case II) will be selected and applied in the study area. Using seawater components and their optical parameters of red tide waters, each stage reflectance spectra of P. donghaiense red tide will be simulated. Compared with those spectra measured in field observation experiments, the changes and characteristics of P. donghaiense red tide reflectance spectra during its vertical migration will be analyzed. Based on the above results, quantitative analyses will be conducted to study the relationships of spectra changes with algal vertical migration. Furthermore, the feasibility and techniques to measure the vertical migration phenomena of the red tide with remote sensing data will be explored. Finally, the Geo-stationary Ocean Color Imager (GOCI) data will be used to delineate the P. donghaiense red tide as application and verifying of such impacts due to algal vertical migration on red tide reflectance spectra. Through the research of this proposal, a better understanding might be achieved about the influences of P. donghaiense vertical migration on red tide reflection spectra, about the rules of changes and characteristics of red tide reflectance spectra through the course of a red tide event, and about the mechanism of red tide remote sensing, so as to provide the theoretical basis for the development and improvement of remote sensing algorithms of red tide. Generally speaking, it has notable scientific significance and practical application value to conduct this research.

赤潮水体反射光谱及其特征是赤潮遥感探测的基础，当前建立的赤潮遥感方法主要用于爆发状态位于海水表层赤潮的探测。本项研究针东海原甲藻垂直迁移现象，研究赤潮孕育-爆发过程中赤潮主体水层垂直迁移对水体反射光谱的影响机制，探索孕育期赤潮参数遥感探测方法。项目采用海上现场观测，获取东海原甲藻赤潮主体水层在不同深度的水体反射光谱，提取垂直迁移过程中水体反射光谱特征和变化规律；结合二类水体反射光谱数值模拟技术，研究东海原甲藻赤潮主体水层深度变化对水体反射光谱影响的形成机理；基于赤潮垂直迁移与水体反射光谱间量化关系，研究赤潮主体水层参数遥感探测可行性及其方法，尝试利用全球首颗地球静止海洋水色卫星（GOCI）的遥感数据开展应用研究。通过本项研究，可望进一步掌握东海原甲藻赤潮生消过程中水体反射光谱及其特征和规律，可加深对赤潮遥感机理的认识，促进赤潮遥感技术的发展，具有显著的科学研究意义和实际应用价值。

东海原甲藻是我国东海海域的优势赤潮藻种，其在水体中通常呈垂直非均匀分布，并存在季节性和日内的垂直迁移现象。项目围绕东海原甲藻垂直迁移过程展开，研究了东海原甲藻赤潮孕育-爆发过程中水体反射光谱的遥感机制，探索了孕育期东海原甲藻赤潮主体水层参数的遥感探测方法。项目观测了浙江近岸海域二类水体的反射光谱，并分析了其光谱特征与影响因素；确定了适用于浙江沿海二类水体的组分光学模型与参数，建立了复杂光学环境下水体反射光谱模拟技术；建立了东海原甲藻垂直迁移量化模型，实现了东海原甲藻赤潮孕育-爆发过程中水体反射光谱模拟，并分析获取了其光谱特征和变化规律；初步建立了东海原甲藻赤潮主体水层参数遥感探测方法。通过本项研究工作，进一步加深了对典型甲藻赤潮水体反射光谱特征与变化规律的认识，在东海原甲藻赤潮垂向迁移遥感方面进行了有益探索，对促进海洋赤潮遥感技术发展具有研究意义和应用价值。