Enhanced mass scattering efficiencies of background dust aerosols over East Asia following the passage of dust plumes

Abstract

The transported dust particles significantly impact global weather and climate. Previous studies focused primarily on the physical and chemical properties of dust plumes, but the interaction mechanism between these dust plumes and background dust aerosols remains unclear. We explored this issue using in-situ observation data of the East Asia dust from the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) during January 2013. We identified a dust plume originating from the Gurbantunggut Desert, which triggered a four-day dust event with an average dust concentration of 67.2 μg m⁻³. Notably, this dust event led to a significant increase in mass scattering efficiencies of dust, shifting from an inverted U-shape to a continuously increasing pattern with wavelength. The enhanced dust mass scattering efficiency inhibited the development of the planetary boundary layer. These changes persisted for at least two weeks after the event, primarily due to the resuspension of deposited dust particles altering the size of background dust particle. Our findings highlight the ability of dust plumes to enhance the scattering efficiency of background dust aerosols and providing new insights into the complex interactions between dust and the atmosphere.