Application of a commercial lidar-ceilometer to studies of aerosols in the atmospheric boundary layer

Abstract

Ceilometers operating on several optical principles have been extensively applied to vertical visibility and cloud base measurements relating to aviation safety. The latest generation of laser time-of-flight backscatter ceilometers use the same optical sounding principle as more powerful and costly research lidar systems. Ceilometers in persistent and unattended operation have become ubiquitous for aviation safety, particularly in Europe and the USA and their potential for use in aerosol studies has therefore become of great interest. CSIR/DPSS has acquired and deployed a Vaisala CL51 ceilometer chiefly for the purpose of investigating the vertical distribution of aerosols in the Atmospheric Boundary Layer (ABL) and cloud base height for application in the modelling of optical surveillance through the ABL. We show some results from ABL analysis of CL51 backscatter data and explore the potential for retrieval of more quantitative aerosol properties such as the lidar ratio. The latter retrievals can be either compared to or calibrated using complementary measurements such as those from AERONET sun-photometers. We conclude that commercial lidar/ceilometers such as the Vaisala CL51 offer cost-effective and long-term potential for aerosol studies in the optical surveillance and atmospheric radiative transfer applications.