Aerodynamic entrainments one of the significant mechanisms of surface dust emission in soil wind erosion processes.Due to its high frequency and regular occurrence,it contributes significantly to regional and global atmospheric dust over long time scales.This study uses the dried lakebed sediments of Qehan Lake in In-ner Mongolia of China as simulation subjects,conducting large-eddy simulations under ideal atmospheric bound-ary layer conditions with different atmospheric stability and background winds to explore the dynamics of turbu-lent dust emission from dried lakebed sediments and the influencing factors.The results indicate:(1)Intermit-tent turbulence generated by surface heating causes dust emission at the surface.(2)Sensible heat flux and fric-tion velocity both positively affect surface dust emission and near-surface dust concentration.Increased wind speed and sensible heat flux result in higher surface dust emission and near-surface dust concentration.(3)Under weak background wind and strong surface sensible heat flux compared to the case of strong background wind and weak sensible heat flux,the formation of strong vertical eddies is more frequent,leading to significantly in-creased vertical velocity.Under the driving force of thermal convection and atmospheric instability,surface dust emission is more prone.
关键词
对流湍流/大涡模拟/沙尘/感热通量/摩擦速度/查干淖尔湖
Key words
convective turbulence/large-eddy simulation/dust/sensible heat flux/rriction velocity/Qehan Lake
维普
万方数据