Integrated impacts of synoptic forcing and aerosol radiative effect on boundary layer and pollution in the Beijing–Tianjin–Hebei region, China
Open Access
- 18 May 2020
- journal article
- research article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 20 (10), 5899-5909
- https://doi.org/10.5194/acp-20-5899-2020
Abstract
Rapid urbanization and industrialization have led to deterioration of air quality in the Beijing–Tianjin–Hebei (BTH) region due to high loadings of PM2.5. Heavy aerosol pollution frequently occurs in winter, in close relation to the planetary boundary layer (PBL) meteorology. To unravel the physical processes that influence PBL structure and aerosol pollution in BTH, this study combined long-term observational data analyses, synoptic pattern classification, and meteorology–chemistry coupled simulations. During the winter of 2017 and 2018, Beijing and Tangshan often experienced heavy PM2.5 pollution simultaneously, accompanied by strong thermal inversion aloft. These concurrences of pollution in different cities were primarily regulated by the large-scale synoptic conditions. Using principal component analysis with geopotential height fields at the 850 hPa level during winter, two typical synoptic patterns associated with heavy pollution in BTH were identified. One pattern is characterized by a southeast-to-north pressure gradient across BTH, and the other is associated with high pressure in eastern China. Both synoptic types feature warmer air temperature at 1000 m a.g.l., which could suppress the development of the PBL. Under these unfavorable synoptic conditions, aerosols can modulate PBL structure through the radiative effect, which was examined using numerical simulations. The aerosol radiative effect can significantly lower the daytime boundary layer height through cooling the surface layer and heating the upper part of the PBL, leading to the deterioration of air quality. This PBL–aerosol feedback is sensitive to the aerosol vertical structure, which is more effective when the synoptic pattern can distribute more aerosols to the upper PBL.Keywords
Funding Information
- National Natural Science Foundation of China (41705002, 41825011)
This publication has 47 references indexed in Scilit:
- The impact of circulation patterns on regional transport pathways and air quality over Beijing and its surroundingsAtmospheric Chemistry and Physics, 2011
- The Nature, Theory, and Modeling of Atmospheric Planetary Boundary LayersBulletin of the American Meteorological Society, 2011
- Analysis of long-range transport of particulate matters in connection with air circulation over Central and Eastern part of EuropePhysics and Chemistry of the Earth, Parts A/B/C, 2010
- Impacts of urban expansion and future green planting on summer precipitation in the Beijing metropolitan areaJournal of Geophysical Research: Solid Earth, 2009
- Radiative forcing by long‐lived greenhouse gases: Calculations with the AER radiative transfer modelsJournal of Geophysical Research: Solid Earth, 2008
- Multisensor Estimation of Mixing Heights over a Coastal CityJournal of Applied Meteorology and Climatology, 2008
- An Improved Mellor–Yamada Level-3 Model: Its Numerical Stability and Application to a Regional Prediction of Advection FogBoundary-Layer Meteorology, 2006
- Fully coupled “online” chemistry within the WRF modelAtmospheric Environment, 2005
- Modal aerosol dynamics model for Europe: development and first applicationsAtmospheric Environment, 1998
- Review: the atmospheric boundary layerEarth-Science Reviews, 1994