AUTHOR=Sun Miao , Chen Peng , Zhang Zhenhua , Zhong Chunyi , Xie Congshuang , Pan Delu 

TITLE=Evaluation of the CALIPSO Lidar-observed particulate backscattering coefficient on different spatiotemporal matchup scales

JOURNAL=Frontiers in Marine Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1181268

DOI=10.3389/fmars.2023.1181268

ISSN=2296-7745

ABSTRACT=<p>The satellite lidar-derived ocean particulate backscattering coefficient (b<sub>bp</sub>) has rarely been validated globally with <italic>in situ</italic> observations, and we need to understand how well the satellite CALIPSO lidar b<sub>bp</sub> approach performs. Whether lidar b<sub>bp</sub> performs better in terms of observation accuracy compared to passive ocean color remote sensing has yet to be evaluated for detailed validation. With the continued deployment of the BGC-Argo float array in the global open ocean in recent years, data have accumulated with a total of 42,932 particulate backscattering coefficients (b<sub>bp</sub>) from 2010 to 2017, allowing for a finer spatial and temporal scale evaluation of the performance of the CALIPSO lidar-observed b<sub>bp</sub>. We evaluated the performance of CALIPSO-retrieved b<sub>bp</sub> products using the data detected by the BGC-Argo floats at 12 spatiotemporal matchup scales and discussed the differences in product performance at various interannual, seasonal, and spatial scales. We compare lidar, float, and ocean color b<sub>bp</sub> at the same locations and times and find that lidar b<sub>bp</sub> outperforms ocean color data. We also analyzed the key conversion factor β(π)/b<sub>bp</sub> at different spatial and temporal scales and found that there was a seasonal difference in the optimal conversion factor.</p>