title: Particle backscatter, extinction, and lidar ratio profiling with Raman lidar in south and north China.
abstract: Aerosol Raman lidar observations of profiles of the particle extinction and backscatter coefficients and the respective extinction-to-backscatter ratio (lidar ratio) were performed under highly polluted conditions in the Pearl River Delta (PRD) in southern China in October 2004 and at Beijing during a clear period with moderately polluted to background aerosol conditions in January 2005. The anthropogenic haze in the PRD is characterized by volume light-extinction coefficients of particles ranging from approximately 200 to 800 Mm(-1) and lidar ratios mostly between 40 and 55 sr (average of 47+/-6 sr). Almost clean air masses were observed throughout the measurements of the Beijing campaign. These air masses originated from arid desert-steppe-like regions (greater Gobi area). Extinction values usually varied between 100 and 300 Mm(-1), and the lidar ratios were considerably lower (compared with PRD values) with values mostly from 30 to 45 sr (average of 38+/-7 sr). Gobi dust partly influenced the observations. Unexpectedly low lidar ratios of approximately 25 sr were found for a case of background aerosol with a low optical depth of 0.05. The low lidar ratios are consistent with Mie-scattering calculations applied to ground-based observations of particle size distributions.
authors.affiliation: Leibniz Institute for Tropospheric Research, Permoserstrasse 15, 04318 Leipzig, Germany. tesche@tropos.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Tesche
authors.forename: Albert
authors.initials: A
authors.lastname: Ansmann
authors.forename: Detlef
authors.initials: D
authors.lastname: Müller
authors.forename: Dietrich
authors.initials: D
authors.lastname: Althausen
authors.forename: Ronny
authors.initials: R
authors.lastname: Engelmann
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.forename: Yuanghang
authors.initials: Y
authors.lastname: Zhang