A New Technique to Retrieve Aerosol Vertical Profiles Using Micropulse Lidar and Ground-based Aerosol Measurements

Abstract. Accurately characterizing the vertical distribution of aerosols and their cloud-forming properties is crucial for understanding aerosol-cloud interactions and their impact on climate. This study presents a novel technique for retrieving vertical profiles of aerosols, cloud condensation nuclei (CCN), and ice nucleating particles (INPs) by combiningmicropulse lidar, radiosonde, and ground-based aerosol measurements. Herein, the technique is applied to data collected by our team at Texas A&M University during the Tracking Aerosol Convection Interactions ExpeRiment (TRACER) campaign. Aerosol size distribution and CCN counter data are used to estimate the value of the aerosol hygroscopicity parameter, κ. The derived κ, together with Mie scattering theory and the relative humidity profiles from the radiosonde, are then used to estimate how much the aerosols have grown at each altitude. This estimate is applied inversely to the aerosol backscatter coefficient profile to produce a dry aerosol backscatter coefficient profile. The dry aerosol backscatter coefficient profile is used to linearly scale surface measurements of aerosol, CCN, and INP concentrations. Combining lidar and ground-based aerosol measurements reduces the assumptions typically needed in lidar-based aerosol retrievals, resulting in a more accurate representation of vertical distributions of aerosol properties. The method could be readily applied to measurements in future field campaigns.