High aerosol load over the Pearl River Delta, China, observed with Raman lidar and Sun photometer

Height–resolved data of the particle optical properties, the vertical extend of the haze layer, aerosol stratification, and the diurnal cycle of vertical mixing over the Pearl River Delta in southern China are presented. The observations were performed with Raman lidar and Sun photometer at Xinken (22.6°N, 113.6°E) near the south coast of China throughout October 2004. The lidar run almost full time on 21 days. Sun photometer data were taken on 23 days, from about 0800 to 1700 local time. The particle optical depth (at about 533–nm wavelength) ranged from 0.3–1.7 and was, on average, 0.92. Ångström exponents varied from 0.65–1.35 (for wavelengths 380 to 502 nm) and from 0.75–1.6 (for 502 to 1044 nm), mean values were 0.97 and 1.22. The haze–layer mean extinction–to–backscatter ratio ranged from 35–59 sr, and was, on average, 46.7 sr. The top of the haze layer reached to heights of 1.5–3 km in most cases.