Characteristics of atmospheric boundary layer based on ground-based remote sensing vertical observation system

This study investigates the atmospheric boundary layer characteristics during pollution episodes in Shenyang's 2024 Spring Festival period through integrated analysis of air pollutant observations, meteorological data, and novel ground-based remote sensing measurements. The results demonstrate that initial-phase severe pollution (AQI > 300) emerged due to the combined effects of firework emissions and stagnant meteorological conditions featuring weak boundary-layer winds (<2 m/s) and suppressed warm air advection. Subsequent mid-term southerly winds facilitated warm air transport, enhancing atmospheric vertical mixing capacity and consequently improving air quality. Final-phase pollution dissipation occurred through cold front-induced air mass renewal. Critical findings reveal that persistent surface inversion layers critically constrained vertical pollutant dispersion, compressing the boundary layer height to 300 m during peak pollution episodes (normally <2,200 m), while firework-derived PM_2.5 exhibited vertical stratification predominantly below 600 m altitude. These observations systematically elucidate the interplay between anthropogenic emissions and boundary layer dynamics in driving wintertime pollution events.