A Glimpse of Ocean Color Remote Sensing From Moon-Based Earth Observations

As the only natural satellite of the Earth, the Moon provides vital location resources and supportive environment for Earth observations, and the Moon-based Earth observation (MEO) has unparalleled advantages in global climate change and large-scale phenomena. The ocean plays an important role in regulating climate and global water and carbon cycle. With an attempt to explore the feasibility of MEO-based marine environment monitoring, this study aimed to investigate the observing geometry and revisiting frequency of the MEO-based ocean color remote sensing and further to explore its quantitative application potentials. Results showed that MEO-based ocean color remote sensing, capturing the Earth on an hourly basis, could observe most part of the ocean for over five times per day; however, both solar zenith angle and view zenith angle were high at high-latitude regions; atmospheric reflectance accounted for most of sensor-measured signal, especially at high solar and view zenith angle, while surface-reflected glint reflectance was also notable at low solar zenith angle; and the remote sensing reflectance retrieved from MEO-based ocean color remote sensing could be used for chlorophyll retrieval. In further studies, more efforts should be paid on how to accurately retrieve remote sensing reflectance at high solar and view zenith angle, which would improve the application capability of MEO for polar regions. Overall, this study demonstrated the great potentials of MEO-based ocean color remote sensing, and MEO would be a new observing perspective and long-term consistent data source for marine environment monitoring.