Weakened Aerosol-PBL Interaction During COVID-19 Lockdown in Northern China.

ABSTRACT: Anthropogenic emissions were greatly constrained during COVID-19 lockdown in China. Nevertheless, observations still showed high loadings of fine particles (PM_2.5) over northern China with secondary aerosols increasing by 15 μg/m³ yet a ∼10% drop in light-absorbing black carbon (BC). Such a chemical transition in aerosol composition tended to make the atmosphere more scattering, indicated by satellite-retrieved aerosol absorption optical depth falling by 60%. Comparison between weather forecast and radiosonde observations illustrated that, without upper-level heating induced by BC, the stabilized stratification diminished, which was conducive for planetary boundary layer (PBL) mixing and thus near-surface pollution dispersion. Furthermore, coupled dynamic-chemistry si

SUBMITTER: Wang Z 

PROVIDER: S-EPMC7883207 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature