Dust haze over Northern China Plain
G.I. Gorchakov1, O.I. Datsenko1, V.M. Kopeikin1, A.V. Karpov1, R.A. Gushchin1, I.A. Gorchakova1, S.F. Mirsaitov2, T.Ya. Ponomareva3
1A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Moscow, Russia
2Moscow Technological University, Moscow, Russia
3Hydrometeorological Centre of Russia, Moscow, Russia
Keywords: dust aerosol, optical and microphysical characteristics, particle size distribution, aerosol mass content, circulation of atmosphere, long-range transport, aerosol mass flux, aerosol radiative forcing
Abstract
According to monitoring data at AERONET stations in Beijing region in the 21th century, the aerosol optical depth can attain 4.0-4.5 during a dust haze. The optical and microphysical characteristic of the tropospheric aerosol are determined by the coarse mode, with a modal radius of particles of ~ 2-4 mm and a mass content of dust aerosol of 11-12 g/m2. In accordance with monitoring data at the Beijing and Xinglong stations in April 2006 and at the Beijing-CAMS station in March 2021, the imaginary part of the refractive index of dust aerosol in an optically dense dust haze was comparatively small, from 0.0005 to 0.003, with the detection probability 54 and 77% at the Beijing and Xinglong stations, respectively. The spatial distribution of the aerosol optical depth and the wind field reanalysis data are analyzed. The analysis has shown the long-range dust aerosol transport from Takla-Makan desert to Northern China Plain in April 2006. The aerosol radiative forcing at the top and bottom of the atmosphere are calculated for the period of dust haze propagation in China. Its efficiency is shown to be 85 W/m2 at the top of the atmosphere and attains 135-140 W/m2 at the bottom in the Beijing region. Using the wind field reanalysis data, aerosol optical depth monitoring data, and retrievals of the optical and microphysical characteristics of the tropospheric aerosol, the dust aerosol mass flux from Takla-Makan desert to Northern China Plain and the daily total dust aerosol mass transport are estimated to be ~ 1.5 ton/s and 1.5 million tons, respectively.
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