Potential of spaceborne Brillouin scattering lidar for global ocean optical profiling

Abstract

The potential of spaceborne Brillouin scattering lidar for generating global ocean optical profiles was studied herein. We analyzed the global distributions of the maximum detectable depths and corresponding optimum wavelengths for spaceborne Brillouin scattering lidar during the day and night, simulated the global vertical profile distributions of the seawater sound speed and Brillouin scattering frequency shift, and discussed the effects of the system parameters and water environment parameters in Case II water on the lidar detection performance and proportion of Brillouin scattering lidar penetrating the upper mixed layer on the global scale. The laser emission wavelength of 490 nm is suitable for detecting open ocean waters, and 540 nm is suitable for detecting coastal waters. The detection depth of the Brillouin scattering lidar operating at night is approximately 10 m greater than that during the day. The vertical profile distributions of the seawater sound and the Brillouin scattering frequency shift decrease as the depth increases from 0 to 200 m in the mid-low latitude regions. The proportions of spaceborne Brillouin scattering lidar penetrating the upper mixed layer in January-February-March, April-May-June, July-August-September, and October-November-December are 75.15%, 76.80%, 59.12%, and 73.10%, respectively. The results indicate that spaceborne Brillouin scattering lidar has great potential for the wide-range and long-term monitoring of upper-ocean water bodies, which would be a good complement to passive satellite ocean color remote sensing technology and the traditional measurement methods of Argo floats, gliders, XBT, and AUV.