Measurements of atmospheric aerosol optical absorption coefficients using photoacoustic spectrometer

Atmospheric aerosol absorption capacity is a critical parameter determining its direct and indirect effects on climate. Accurate measurement is highly requested for study of the radiative budget of the Earth, photoacoustic spectroscopy is commonly recognized as one of the best candidates to measure the optical absorption coefficient (OAC) of aerosols. A Scanning mobility particle sizer (SMPS) and a homemade photoacoustic aerosol absorptionmeter were used to monitor the size distribution and OAC of the ambient aerosols at suburb of Hefei city, the real-time trends of OAC and size distribution in a serial time were acquired. Properties of the size distribution at different time which was classified into two distribution mode were analyzed in detail. The measured data shows that OAC has a well positive correlation with size distribution and number concentration of the atmospheric aerosol respectively and the emission of carbonaceous aerosol is the chief factor of the effect on OAC.