Abstract: To reveal the influence of the characteristics of the boundary layer structure in Foshan City,
China, during the dry season on air quality and develop more scientific pollution control measures, a
comprehensive three-dimensional observation of atmospheric boundary layer structure in Foshan was
carried out by using the ground-based remote sensing equipment (including wind profiler radar, lidar and
microwave radiometer) at Shunde, Chancheng and Sanshui stations in Foshan. The research results show
that: (1) There are significant differences in the boundary layer structure of different regions in Foshan City.
For example, as the urbanization degree of Chancheng is higher than that of Sanshui and Shunde, the wind
speed at the bottom of the boundary layer in Chancheng is the lowest and the horizontal diffusion condition
is the worst. While Shunde, located in the south of Foshan, has more water vapor and the highest pollutant concentration, which may be related to the hygroscopic growth of aerosols. (2) The decrease of boundary
layer height leads to a sharp increase in pollutant concentration near the ground. (3) In Foshan area, there is
generally a small wind layer with wind speed below 2.6 m/s near the ground layer, and the thickness of the
small wind layer has an obvious diurnal variation, with the maximum thickness in the early morning, which
is prone to pollution. In addition, the thickness of the small wind layer is highly correlated with the
concentration of fine aerosol particles, and the prediction of the small wind layer thickness can be carried
out in the later stage.

Key words: atmospheric boundary layer, small wind layer thickness, wind profile radar, lidar, microwave radiometer