Boundary layer and air quality monitoring with a commercial lidar ceilometer

摘要

The Vaisala Ceilometer CL31 is a compact and low-cost all-weather lidar designed to report cloud base height and vertical visibility. It works 24 hours a day in fully-automated, hands-off operation mode. Its enhanced optical and electronic concept enables it for tasks that go far beyond its standard duties. Four different areas will be treated in the scope of this paper. 1. Mixing height assessment from attenuated backscatter profiles. 2. Comparison of particulate matter concentration, near-range ceilometer backscatter, and extinction reported by a ceilometer. 3. Backscatter profiles from a ceilometer that was installed for one year in an industrial area pointing in a nearly horizontal direction were evaluated in respect of possibilities to monitor chimney plumes, spray caused by cars driving on a wet road, and other phenomena. 4. The standard profile report frequency of the CL31 ceilometer is 0.5 Hz. If the measuring range is reduced to 100 m, the profile report frequency can be raised to 100 Hz, opening new fields of application like the investigation of falling hailstones.