1Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
3State Environmental Protection Key Laboratory of the Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Science, Shanghai 200070, China
1Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2Department of Physics, National Institute of Technology Calicut, Calicut 673601, Kerala, India
3State Environmental Protection Key Laboratory of the Cause and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Science, Shanghai 200070, China
Received: 25 Feb 2021 – Accepted for review: 05 Mar 2021 – Discussion started: 09 Mar 2021
Abstract. The study of aerosol optical properties is essential to understand its impact on the global climate. In our recent field measurement, a photoacoustic extinctiometer (PAX) and a cavity attenuated phase shift albedo monitor (CAPS-ALB) were used for online aerosol optical properties measurement. Laboratory calibration with gas and particle samples were carried out to correct disagreements of field measurements. During particle calibration, we adopted ammonium sulfate (AS) samples for scattering calibration of nephelometer parts of both the instruments, then combined with number-size distribution measurements into MIE model for calculating the value of the total scattering (extinction) coefficient. During gas calibration, we employed high concentration NO2 for absorption calibration of PAX resonator, then further intercompared the extinction coefficient of CAPS-ALB with a cavity-enhanced spectrometer. The correction coefficient obtained from the laboratory calibration experiments was employed on the optical properties observed in the filed measurements correspondingly, and showed good result in comparison with reconstructed extinction from the IMPROVE model. The intercomparison of the calibrated optical properties of PAX and CAPS-ALB in field measurement were in good agreement with slopes of 1.052, 1.024 and 1.046 for extinction, scattering and absorption respectively, which shows the reliability of measurement results and verifies the correlation between the photoacoustic and the cavity attenuated phase shift instruments.
Based on the intercomparison of a photoacoustic and a cavity attenuation phase shift instruments, this manuscript has corrected and calibrated the data of recent field measurement. It showed good agreement and closure correlation in the optical properties measured from different optical methods, and the scattering coefficient part plays a crucial role as the bridge in constructing correlation of both instruments.
Based on the intercomparison of a photoacoustic and a cavity attenuation phase shift...
