Spaceborne high-spectral-resolution lidar ACDL/DQ-1 measurements of the particulate backscatter coefficient in the global ocean

Spaceborne lidars have demonstrated outstanding global ocean observation in terms of sampling at day- and night-time and penetrating thin cloud and aerosol layers. A spaceborne high-spectral-resolution lidar (HSRL) has the potential to provide accurate optical properties by decreasing the number of assumptions in the retrieval algorithm in comparison with classical elastic spaceborne lidar. In this paper, we report the first ocean application from both particulate and molecular scattering measurements of spaceborne HSRL, namely Aerosol and Carbon Detection Lidar (ACDL) onboard China DQ-1 satellite. We use the ACDL/DQ-1 HSRL to quantify particulate backscatter coefficient b_bp in the global ocean, with a novel algorithm exploiting the column-integrated particulate and molecular signals. The ACDL-derived b_bp data agree well with MODIS-derived data through along-track and global comparisons. It also presents high correlations with the Argo floats in-situ data under various spatial and temporal matching windows. The ACDL/DQ-1 is anticipated to become an important part of the global ocean satellite observations addressing some limitations of traditional passive ocean colour observation.