Effect of aerosol hygroscopic growth on radiative forcing based on a Raman lidar

The hygroscopic properties of atmospheric aerosols have a very important effect on radiative forcing. In this study, we investigate the influences of aerosol hygroscopic properties on radiative forcing based on Raman lidar. The optical properties of aerosol particle were measured using Raman lidar in Yinchuan, China, in 2022. The temperature and relative humidity (RH) profiles were then retrieved from the Raman lidar observations. The scattering hygroscopic growth factor f(RH), defined as the ratio of the aerosol scattering coefficient at a specific RH to the aerosol scattering coefficient in the dry state at a specified wavelength, was measured using Raman lidar. The aerosol hygroscopic growth factor increased from 1 to approximately 1.06 when the RH increased from 30 to 37%. Finally, the radiative forcing varied under the influence of different aerosol scattering hygroscopic growth factors, and this was estimated using the aerosol hygroscopic growth factors obtained by lidar detection and inversion. When increasing the RH from 30 to 37%, there was a downward trend in aerosol radiative forcing. It can be inferred that aerosol hygroscopic properties are key factors that cannot be ignored in assessing the role of aerosols in radiative forcing.