Comparison of scanning aerosol LIDAR and in situ measurements of aerosol physical properties and boundary layer heights

Modern remote sensing methods, as well as airborne in situ measure- ments by unpiloted aerial vehicles (UAV) or balloons, are suitable tools to improve our understanding of the role of aerosol particles in the atmosphere. To validate the measurement capabilities of three relatively new measurement systems and to bridge the gaps that are often encountered between remote sensing and in situ ob- servation, as well as to investigate aerosol particles in and above the boundary layer, we conducted two measure- ment campaigns and collected a comprehensive dataset employing a scanning aerosol lidar, a balloon-borne ra- diosonde with the Compact Optical Backscatter Aerosol Detector (COBALD), an optical particle counter (OPC) on a UAV, and a comprehensive set of ground-based instruments.

The extinction coefficients calculated from near-ground-level aerosol size distributions measured in situ are well correlated with those retrieved from lidar measurements, with a slope of 1.037 ± 0.015 and a Pearson correlation coefficient of 0.878, respectively. Verti- cal profiles measured by an OPC-N3 on a UAV show similar vertical particle distributions and boundary layer heights to lidar measurements. However, the sensor, OPC-N3, shows a larger variability in the aerosol backscat- ter coefficient measurements, with a Pearson correlation coefficient of only 0.241.