Development and validation of a CCD-laser aerosol detective system for measuring the ambient aerosol phase function

摘要

Aerosol phase function represents the angular scattering property ofaerosols, which is crucial for understanding the climate effects of aerosolsthat have been identified as one of the largest uncertainties in theevaluation of radiative forcing. So far, there is a lack of instruments withwhich to measure the aerosol phase function directly and accurately inlaboratory studies and in situ measurements. A portable instrument with highangular range and resolution has been developed for the measurement of thephase function of ambient aerosols in this study. The charge-coupleddevice-laser aerosol detective system (CCD-LADS) measures the aerosol phasefunction both across a relatively wide angular range of 10–170° andat a high resolution of 0.1°. The system includes a continuous laser,two charge-coupled device cameras and the corresponding fisheye lenses. TheCCD-LADS was validated by both a laboratory study and a field measurement.The comparison between the aerosol phase function retrieved from CCD-LADS andMie-scattering model shows good agreement. Compared with the TSI polarnephelometer, CCD-LADS has the advantages of wider detection range and betterstability.