Studies of urban aerosols in the Pearl River Delta Region using lidar

Abstract

In the Pearl River Delta (PRD) Region of China, three Lidar systems have been employed for monitoring aerosol distribution: a mobile micro-pulse Lidar of City University of Hong Kong (CityU), a scanning Doppler Lidar in Hong Kong International Airport (HKIA) and a horizontal Mie Lidar in Macau Meteorological and Geophysical Bureau (SMG). In this thesis, details of the Lidar systems and the methods of data acquisition are described. Some representative results obtained by the Lidar systems are presented. The measurements in Macau show higher particulates concentration could be observed near the power station and densely urbanized districts in the Macau peninsular. Comparisons are also made between the mean respirable suspended particulates (RSP) values from Lidar profiles and particulate matter (PM) values from SMG. General agreement can be observed. Additionally, the algorithm to generate visibility map using the backscattered data from the horizontal scan of the Doppler Lidar together with the visibility measurements from forward scatter sensors is described. The visibility maps are applied to monitor the haze development and tornado episode. Besides, the diurnal and monthly variations of boundary layer in Hong Kong are also studied. The highest monthly averaged value of the boundary layer can be registered in October, while the lowest values are observed in spring and late winter. The boundary layers increase gradually throughout the day, peak in the afternoon and decrease after solar heating ceased. Ultimately, comparisons are made between the vertical profiles obtained from Lidar measurements and a mesoscale model. Large discrepancy can be observed.

Date of Award	15 Feb 2007
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Yuk Sun Andrew CHENG (Supervisor)