初级生产驱动着海洋生态系统的物质循环和能量流动。海色卫星遥感技术的发展极大地促进了对初级生产力分布规律和调控机制的认识，但是遥感技术一直存在不能直接反演浮游植物光合参数的问题，影响了初级生产力估算的准确度。国际上新近提出了遥感反演光适应参数Ek的初步算法，但仍需要用实测数据进行验证和进一步的改进，本项目将针对“南海浮游植物光适应参数Ek的分布规律以及遥感值与实测值相关关系”这一科学问题，通过现场调查研究、数据综合分析和遥感资料分析等手段，研究南海浮游植物光适应参数Ek的时空分布特征，解析影响Ek时空变动的主要调控因子，在此基础上进行遥感反演Ek和实测Ek的比对，分析其相关关系的影响因素，最终提出遥感反演Ek的校正方法。Ek指示光合作用的半饱和光强，是决定初级生产力的关键模型参数之一。实现和改进遥感反演Ek的方法，将为未来实现卫星遥感直接反演海洋初级生产力奠定坚实的基础。

Primary production is driving the matter cycling and energy flow of marine ecosystem. The development of ocean color remote sensing technology has greatly promoted the knowledge of the distribution pattern of primary production in the sea and the underlying mechanisms. However, the difficulty remains in improving the accuracy of primary production estimates without the retrieval of photosynthetic parameters from space. Recently, a tentative approach to retrieve the photoadaptation parameter Ek by remote sensing has been proposed; validation with field data and further improvement are necessary. To address the scientific question of “the distribution pattern and the controlling factors of photoadaptation parameter Ek in the South China Sea, and the correlation between measured and remote sensing retrieved Ek”, this project will study the spatio-temporal distribution pattern of Ek of phytoplankton community in the South China Sea, then reveal the major controlling factors, eventually find the method of correction for accurate Ek by remote sensing, through the means of field investigations, comprehensive data analysis and remote sensing data analysis. Ek is the half-saturation constant of phytoplankton photosynthesis that is one of key model parameters of primary production. The implement and improvement of remote sensing Ek algorithm will prepare a firm ground for the future development of method to retrieve primary production directly by ocean color remote sensing.