面向东中国海浮游植物粒径等级的遥感探测机理研究

Extracting phytoplankton size classes (PSCs) in waters is of significance for understanding phytoplankton community structure, studying phytoplankton function diversity, and revealing biogeochemical processes of water ecosystem. There exists a very complex distribution of PSCs in coastal waters. At present, there are still little knowledge about PSCs distribution and less effective remote sensing algorithms for detecting PSCs for coastal waters. For this reason, this study takes typical coastal waters (East China Sea) as experimental areas, for collecting in situ observed data. Weight coefficients of phytoplankton diagnostic pigments will be first explored that should be suitable for the coastal waters. By coupling the developed weight coefficients with phytoplankton species densities, a novel quantification factor that simultaneously takes phytoplankton biomass and cell particle numbers into account will be developed for describing the PSCs variations in coastal waters. A subsequent study goal is to extract phytoplankton reflectance signal from the total signals of water bodies, and further to explore spectral sensitive responses of the quantification factor of phytoplankton size classes to remote sensing reflectance, and finally to propose a spectral expression quantity for reflecting the PSCs variations by using remote sensing reflectance. Then, the satellite data will be used to explore a mathching mechanism with the established spectral expression quantity. Combining with the satellite data, various modeling methods will be assessed comprehensively, and then selected to develop the remote sensing algorithms of detecting the PSCs in coastal waters. The findings in this study will provide the theoretical basis and technique methods for revealing the distribution characteristics of phytoplankton size classes, and further expand the application of water color remote sensing, and promote the development of refinedly monitoring water condition of coastal waters.

针对“我国近海水体浮游植物粒径等级分布特征不明及遥感探测方法缺失”这一十分关键而又尚未得到合理解决的科学问题，本研究拟以典型近海海域（东中国海）为试验区，探索合适的浮游植物诊断色素的权重系数，并耦合种群数量分布，研发提出兼顾浮游植物生物量和细胞粒子个数信息的量化表征因子，用以定量描述浮游植物粒径等级的变化；研究提取蕴含相对纯粹浮游植物信息的水体反射信号，进而挖掘量化表征因子对水体反射信号的敏感响应，并基于水体反射信号，研究提出反映浮游植物粒径等级变化的光谱映射表征量；结合卫星遥感数据，探索与光谱映射表征量之间的关联匹配机制，进而研究量化表征因子的模型构建方法，经综合评估，最终提出适于东中国海水体的浮游植物粒径等级的遥感探测模型。本课题研究成果将为揭示浮游植物粒径等级的分布特征及其时空演化，提供理论依据和方法支撑，并将进一步拓展水色遥感应用，促进海洋水环境精细化监测的发展。

针对“我国近海水体中浮游植物粒径等级分布特征不明及遥感探测方法缺失”这一十分关键而又尚未得到合理解决的科学问题，本项目以典型海域（东中国海）水体为试验区，研究探索浮游植物粒径等级的量化表征因子，深入挖掘量化表征因子对水体反射信号的光谱响应机制，提出适于近海及海岸带水体的浮游植物粒径等级的遥感探测模型，为揭示浮游植物粒径等级的分布特征及其时空演化提供理论依据和方法支撑。针对渤海、黄海和东海水体，共计开展了6个航次的综合野外遥感调查实验，本项目获取了水体各诊断色素浓度、水体固有光学量、水体表观光学量、水体各组分浓度等数据，完成数据处理。分析了各参数的变化分布，重点概括了各诊断色素和浮游植物粒径等级的统计分布特征，并分析与叶绿素a浓度之间的关系，建立了适于东中国海域水体的诊断色素权重系数。通过诊断色素，分析微微型、微型和小型浮游植物对总浮游植物叶绿素a的贡献分布；结合实测的浮游植物吸收光谱，开展了关联耦合分析，研究提出了适于近海海域水体的浮游植物粒径等级的量化表征因子。开发了适于近海海域水体的浮游植物粒径等级的遥感探测模型。制作了20年的长时间序列（2007-2017年）浮游植物粒径等级的时空分布专题产品。基于长时序卫星遥感数据，分析了东中国海浮游植物粒级结构的时空分布特征，并结合相关环境参数，分析了影响浮游植物粒径结构变化的主导因素及耦合关系。本项目通过室内分析实验、野外原位观测、卫星遥感建模等方法，开展了针对近海及海岸带水体浮游植物粒径等级的遥感探测模型研究，这为认识海洋水体浮游植物粒径等级的分布特征和揭示其时空演化规律提供了技术方法支撑，为拓展水色遥感的应用方向和促进近海水体环境的精细化监测做出了积极的贡献。受本该基金项目资助，课题组共发表37篇研究论文（包括SCI论文28篇，EI论文2篇），其中第一标注SCI论文4篇，第二标注SCI论文11篇，申请发明专利1项，已超额完成项目计划要求。