资源环境科技发展态势分析平台

Transboundary-local aerosols interaction requires to be comprehensively understood in urban air quality research. A year-long intensive observation of the atmospheric boundary layer (ABL) at multiple sites in Hong Kong was conducted using a four-Doppler Light Detection and Ranging (LiDAR) network with different scan modes. Results show that heterogeneity of the ABL in terms of mixing layer height and wind shear was induced by orographic topography. Interaction between local and advected aerosol layers during a transboundary air pollution (TAP) episode was identified by the network. During TAP episode, downward transport of transboundary aerosol relied on small scale eddies with weak wind speed in night-time, while the transport of surface local aerosol to upper level was the dominated process in daytime, but the heterogeneity of the ABL affected by terrain determined the capacity of the mixing, eventually resulting in the opposite transport direction of aerosol in the transboundary-local aerosols interaction.