Diurnal Behavior of Aerosol Optical Properties Studied with Lidar and Ground-Based Instruments

Abstract

<jats:p>The combined use of remote sensing and in-situ monitoring instruments could help improve the assessment of near-surface aerosol properties. In this paper, we analyze the diurnal behavior of aerosol extinction coefficients, αExt(λ), at λ=349 and 550 nm using a lidar and a present weather detector, respectively. We utilize the aerosol optical thickness (AOT), single scattering albedo (SSA), and Ångström exponent (AE) from SKYNET sky radiometer, and AE from aethalometer, and the number distribution from optical particle counter to evaluate the effect of relative humidity (RH) on aerosol extinction coefficients. It is found that although αExt(λ) often exhibits a positive correlation with the ambient RH, this relation is obscured when both the number distribution and particle size change simultaneously. Moreover, αExt at 349 nm is more sensitive to this change than at 550 nm.</jats:p>