Particulate Backscattering in the Global Ocean: A Comparison of Independent Assessments

How well do we know the particulate backscattering coefficient (b bp ) in the global ocean? Satellite lidar b bp has never been validated globally and few studies have compared lidar b bp to b bp derived from reflectances (via ocean color) or in situ observations. Here, we validate lidar b bp with autonomous biogeochemical Argo floats using a decorrelation analysis to identify relevant spatiotemporal matchup scales inspired by geographical variability in the Rossby radius of deformation. We compare lidar, float, and ocean color b bp at the same locations and times to assess performance. Lidar b bp outperforms ocean color, with a median percent error of 18% compared to 24% in the best case and a relative bias of −11% compared to −21%, respectively. Phytoplankton carbon calculated from ocean color and lidar exhibits basin‐scale differences that can reach ±50%.