Some uncommon observations of suspending particulates in the air in Hong Kong by ground-based remote-sensing meteorological instruments

Suspending particulates such as volcanic ash, sand/dust and smoke from fire are not commonly observed in Hong Kong. There are some recent events with the setting in of such particulates and their observations by the ground-based remote sensing meteorological instruments are documented in this paper. The equipment in use includes an aerosol LIDAR, Doppler LIDARs and dual polarization weather radars. They are found to provide new insights into the observations of these suspending particulates in Hong Kong, not observed in the territory before and generally consistent with the observations of similar phenomena in other parts of the world. In particular, the equipment provides clear signature about the set-in, dispersion and, if possible, deposition of the particulates, and such observations are found to be in line with the meteorological forecasts by numerical weather prediction models, including a dispersion model whose results are described here. This paper is considered to be useful as reference for weather monitoring of such uncommon particulates in this part of the world. • Novel observations of three very rare pollution cases in Hong Kong • Numerical simulation of the spreading of smoke in comparison with observations • Backward trajectory analysis of the origin of volcanic ash and sand/dust weather