A Comparison of the Different Stages of Dust Events over Beijing in March 2021: The Effects of the Vertical Structure on Near-Surface Particle Concentration

Mineral dust is of great importance to climate change, air quality, and human health. In this study, multisource data, including the reanalysis data remote sensing were used compare three events that occurred in March 2021 over Beijing reveal effects atmospheric vertical structure on near-surface concentration. The combined effect Mongolian cyclone a wide persistent cold-front induced two (E1: from 15 16 E3: 28 29). E1 was more intense, extensive, longer-lasting than E3 due combination stronger cyclone, slower high/cold surface pressure, low-level jet. However, under appropriate configurations temperature pressure fields between high low altitudes, weak updrafts still could elevate up 850 hPa, as during E2 22 23. emission inferior E3, which contributes concentration near E2. On other hand, downdraft strength directly affected both distribution particles. There strong temporal consistency occurrence touchdown. E1, continuous caused maximum be above 4000 ?g/m3 at around 200 m. contrast, height mass about 800 m transient downdraft, weakened its visibility. Besides, motion most become suspended air. Overall, large resulted active source region, lengthy downdrafts led ultrahigh particle surface.