Comparative Study on the Atmospheric Boundary Layer Height Variety over Suburban and Rural Areas of Beijing by Using a Radar Wind Profiler

The spatial and temporal variability of the atmospheric boundary layer (ABL) height over regions with complicated terrain is still poorly studied due to the fact that its value varies significantly with topography. With the help of the data from radar wind profilers obtained in 2022, the study investigates characteristics of the ABL height variations over a typical mountainous rural site (Yanqing) and plain suburban site (Nanjiao) in Beijing, China in clear-sky conditions by using a normalized signal-to-noise ratio threshold. The results point to strongly contrasting features on the diurnal and seasonal variations. It is interesting to note that at the plain suburb site, the ABL is repressed in the morning and develops rapidly in the afternoon in spring, while it evolves more quickly in winter. An investigation of seasonal variations in wind profiles has led to a deeper understanding of the evolution of local plain-to-mountain circulation in this region, as well as of potential impacts on seasonal changes in the ABL, especially in spring and summer. Furthermore, the steady ABL caused by aerosols and heightened urban heat accumulation may be linked to the rigid ABL development over plain suburb canopy in autumn and winter. The results are helpful for improving knowledge of meteorological conditions contributing to air pollution in mountainous areas.