This paper introduces the DISRELCUB (Direct In-situ Study of REsidual Layer Chemistry in Urban Beijing) experiment conducted on the roof of CITIC (China International Trust and Investment Corporation) Tower, which stands 528 m above the ground in urban Beijing. The aim is to directly study in-situ residual layer chemistry and its influence on the air quality on the ground surface. The experiments were performed during March-April 2022 and March-April 2024, respectively. For the first time, we can present a picture of the nano-particle formation and growth owing to residual layer chemistry in a megacity. In the first part, we introduce the experimental design, the observation station and the instruments; in the second part, we present boundary layer thermodynamics during observation periods as well as the characteristics of meteorological variables, aerosol and trace gases measured on the 528-m platform, 143-m platform and ground surface, respectively. In the third section, we show highlights of some key radical reservoir molecules and vapors associated with nano-particle formation and growth on the 528-meter platform; in the last part, we quantify the contribution of residual layer chemistry to the ground surface by turbulence with a large eddy simulation model.

 

Residual layer,Nano-particle formation and growth,Gas-to-particle conversion,Large eddy simulation