An overview of aerosol lidar: Progress and prospect

Aerosols, solid or liquid particles suspended in the atmosphere, are an important component in the troposphere. It is well known that atmospheric aerosols have significant impacts on environment, climate and ecosystem. Thus, the knowledge of the spatial-temporal distribution and evolution of aerosol physical-chemical-optical properties with high resolution is of great importance to quantitatively and accurately assess their climate and environmental effects. As an advanced remote sensing technology, lidar has been widely used to observe aerosol properties around the world, which is mainly attributed as its unique advantages in large detection range and high spatial-temporal resolutions. The basic principle of lidar remote sensing is that after sending lasers to the atmosphere backscattering signals from aerosols can be detected and further analyzed. This paper summarizes the research progress of lidar for detecting atmospheric aerosol over the past decades from three aspects: Firstly, the main types of lidar that can be used for atmospheric aerosol detection are briefly introduced, such as Mie scattering lidar, polarized lidar, Raman lidar, high spectral resolution lidar, fluorescent lidar, etc. They usually employ several principles of physics, such as Mie scattering, Raman scattering and fluorescence scattering. Secondly, the lidar-based research progress of aerosol properties at home and aboard, such as optical properties (e.g., extinction/backscattering coefficient, lidar ratio, aerosol optical depth, Ångström exponent), size (e.g., color ratio), shape (e.g., depolarization ratio), composition (e.g., dust, smoke, sulfate, etc.), and concentration (e.g., mass concentration), are individually introduced. Finally, with the advances of photoelectric technology, artificial intelligence, and precision machining technology in recent years, the future development of aerosol lidar is prospected in this review paper. Lidar will be more miniaturized and intelligent, making it easier to carry on Unmanned Aerial Vehicle platforms. Abundant aerosol parameter inversion algorithms will be established. More ground-based lidar observation network and space-borne lidar projects will be established and improved successively. © 2022, Science Press. All right reserved.