Monitoring Optical Properties of Aerosols with Cavity Ring-down Spectroscopy

摘要

This article describes the design and performance of a cavity ring-down spectroscopic (CRDS)instrument for measuring extinction coefficients of laboratory and ambient atmospheric aerosols. Throughaveraging 1000 individual waveforms, a minimum detectable aerosol extinction coefficient of 6.1×10-7m-1isachieved. Tests with polystyrene spheres (PSS), we suggested this CRDS agrees well with visibilityobservations from Shanghai Meteorological Bureau. Combined with the TSI integrating nephelometer andNOxanalyzer, CRDS was used to monitor the optical properties of ambient aerosols in the heavy pollutionepisode. The uncertainty for using the CRDS and TSI nephelometer to measure single scattering albedo (SSA)in an ambient measurement is estimated to be＜12%.