Ocean transparency inversion and its merging from Terra-MODIS and NPP-VIIRS satellites on the Northwest Pacific

In this paper, the ocean transparency product is derived and merged over the Northwest Pacific from two ocean color sensors: Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra platform, and Visible Infrared Imaging Radiometer Suite (VIIRS) on the NPP platform. Firstly, the empirical inversion algorithm of ocean transparency was developed with the in-situ measured Secchi depth and remote-sensing reflectance. Then the ocean transparency over the Northwestern Pacific was produced with the constructed model and the data of MODIS/Terra and VIIRS/NPP. Finally, the objective analysis method was applied to merge the above ocean transparency product. The merged product is evaluated from the spatial coverage ratio and the accuracy of the result. The evaluation result showed that the spatial coverage of Objective Analysis method products is much larger than that of the single sensor products. Compared with the operational product from GlobColour website, our result is acceptable. The objective analysis merging method can be used widely without timeliness requirement.