Aerosol and cloud characteristics analysis methods using multiple kinds of Raman lidar signals

In this paper, we introduce three kinds of methods for the analysis of aerosol and cloud droplet characteristics: backscattering color ratio at two wavelengths (color ratio), aerosol liquid-water content, and cloud droplet size distribution using the liquid water and aerosol extinction coefficients. Based on theoretical perspective as well as our experimental results, we find that the liquid-water Raman scattering efficiency does not depend on four orders of particle size, but rather, depends on less than four orders, particularly in a smaller effective size distribution than Mie scattering efficiency. Therefore, we conclude that the color ratio method can be applied to aerosols, while the ratio between the liquid water Raman and extinction coefficients can be applied to cloud droplet size measurements.