Revisiting sea surface mean square slopes with anisotropy slope distribution and spaceborne lidar measurements

The applicability of the anisotropy Gram–Charlier slope distribution for global ocean roughness characterization is assessed using the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and the Advanced Microwave Scanning Radiometer 2 (AMSR-2) matchup dataset. A revisited mean square slope (MSS) and wind speed relationship is proposed and remains consistent with the Hu et al . model [ Atmos. Chem. Phys. 8 , 3593 ( 2008 ) 10.5194/acp-8-3593-2008 ] in the wind speed inversion, yielding comparable deviation values to the AMSR-2 product of 0.11 and −0.12ms −1 , R 2 of 0.83 and 0.84, and RMSE of 1.27 and 1.12ms −1 , respectively. Forward sea surface backscatter simulations combining different mean square slope models with slope distributions demonstrate that incorporating anisotropy can improve the directional sensitivity. The general anisotropy slope distribution with a matched MSS parameter can improve the representation of the surface azimuthal structure in optical remote sensing and supports a more physically consistent interpretation of spaceborne lidar measurements.