Characteristics of the summer nighttime stable boundary layer in the hinterland of the Taklamakan Desert and its effect on dust aerosols concentration
Influenced by the thermal properties of the desert subsurface,the nocturnal atmospheric boundary layer in the desert region exhibits significant alterations in stratification stability,boundary layer dynamics,and thermodynamics,impacting the emission and dispersion processes of dust aerosols.Despite being a crucial source of dust aerosols in Asia,there is a lack of quantitative assessment of the effects of nocturnal atmospheric stratification stability,boundary layer dynamics,and thermodynamics on dust aerosols in the Taklamakan Des-ert.To address this gap,this paper utilizes GPS sounding and near-surface atmospheric observations to analyze the structural changes of the boundary layer and the characteristics of near-surface dust aerosol concentration un-der different stability conditions during the night.The study also investigates the mechanisms driving the changes in near-surface stratification stability and the thermal and dynamical factors influencing dust aerosol variations.The findings reveal that under clear and floating dust weather,the stability of the nocturnal boundary layer can be categorized as weak,strong,and very strong stability,while a neutral boundary layer occurs during dust storms.The strong weather processes disrupt the stable boundary layer structure.Enhanced stability of the near-surface layer at night favors the accumulation of dust aerosols under clear and floating dust weather,with the op-posite effect observed during dust storms.Vertical wind shear predominantly influences the variation in dust aero-sol concentration.This shear is intensified at night under clear and floating dust weather,promoting vertical dif-fusion of dust aerosols and reducing near-surface concentrations.Conversely,during dust storms,a significant positive correlation exists between vertical wind shear disturbed by the weather system and dust aerosol concen-tration,facilitating local dust uplift and the transport of upper-layer dust to the near-surface layer,thereby en-hancing dust aerosol concentrations.The results of this study will contribute to a deeper understanding of desert land-atmosphere interactions,physical processes in the nocturnal boundary layer,and the impacts of these inter-actions.
Taklamakan Desertnighttime atmospheric boundary layerstratification stabilitythermal and dy-namic factorsdust aerosols
万方数据
维普
