Evaluation of the CALIPSO Lidar-observed particulate backscattering coefficient on different spatiotemporal matchup scales
Miao Sun, Peng Chen, Zhenhua Zhang, Chunyi Zhong, Congshuang Xie, Delu Pan
Abstract
The satellite lidar-derived ocean particulate backscattering coefficient (b bp ) has rarely been validated globally with in situ observations, and we need to understand how well the satellite CALIPSO lidar b bp approach performs. Whether lidar b bp 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 bp ) from 2010 to 2017, allowing for a finer spatial and temporal scale evaluation of the performance of the CALIPSO lidar-observed b bp . We evaluated the performance of CALIPSO-retrieved b bp 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 bp at the same locations and times and find that lidar b bp outperforms ocean color data. We also analyzed the key conversion factor β(π)/b bp at different spatial and temporal scales and found that there was a seasonal difference in the optimal conversion factor.