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The feedback effects of aerosols from different sources on the urban boundary layer in Beijing China
2023
Xin, Jinyuan | Ma, Yongjing | Zhao, Dandan | Gong, Chongshui | Ren, Xinbing | Tang, Guiqian | Xia, Xiangao | Wang, Zifa | Cao, Junji | de Arellano, Jordi Vilà Guerau | Martin, Scot T.
The interaction of aerosols and the planetary boundary layer (PBL) plays an important role in deteriorating urban air quality. Aerosols from different sources may have different effects on regulating PBL structures owing to their distinctive dominant compositions and vertical distributions. To characterize the complex feedback of aerosols on PBL over the Beijing megacity, multiple approaches, including in situ observations in the autumn and winter of 2016–2019, backward trajectory clusters, and large-eddy simulations, were adopted. The results revealed notable distinctions in aerosol properties, vertical distributions and thermal stratifications among three types of air masses from the West Siberian Plain (Type-1), Central Siberian Plateau (Type-2) and Mongolian Plateau (Type-3). Low loadings of 0.28 ± 0.26 and 0.15 ± 0.08 of aerosol optical depth (AOD) appeared in the Type-1 and Type-2, accompanied by cool and less stable stratification, with a large part (80%) of aerosols concentrated below 1500 m. For Type-3, the AOD and single scattering albedo (SSA) were as high as 0.75 ± 0.54 and 0.91 ± 0.05, demonstrating severe pollution levels of abundant scattering aerosols. Eighty percent of the aerosols were constrained within a lower height of 1150 m owing to the warmer and more stable environment. Large-eddy simulations revealed that aerosols consistently suppressed the daytime convective boundary layer regardless of their origins, with the PBL height (PBLH) decreasing from 1120 m (Type-1), 1160 m (Type-2) and 820 m (Type-3) in the ideal clean scenarios to 980 m, 1100 m and 600 m, respectively, under polluted conditions. Therefore, the promotion of absorbing aerosols below the residual layer on PBL could be greatly hindered by the suppression effects generated by both absorbing aerosols in the upper temperature inversion layer and scattering aerosols. Moreover, the results indicated the possible complexities of aerosol-PBL interactions under future emission-reduction scenarios and in other urban regions.
اظهر المزيد [+] اقل [-]Current and historical relationships between the tissue nitrogen content of a snowbed bryophyte and nitrogenous air pollution
1996
Woolgrove, C.E. | Woodin, S.J. (Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB9 2UD (United Kingdom))
Rainfall composition in Minnesota: integrating the chemistry, synoptic meteorology and numerical modelling
1999
Krupa, S. | Nosal, M. (Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (USA))
Reversibility of stemflow-induced soil acidification in Swedish beech forest
1991
Falkengren-Grerup, U. | Bjork, L. (Dep. Plant Ecology, Univ. Lund, S-223 61 Lund (Sweden))
Trace organic compounds in the atmosphere at the forest locations "Postturm", Forestry Commission Farchau/Ratzeburg and "Donaustauf" near Regensburg
1992
Figge, K. (NATEC (Inst. fuer Naturwissenschaftlich-Technische Dienste) G.m.b.H., Hamburg (Germany)) | Dommroese, A.M.
[Agricultural meteorological research at the Danish Research Service for Soil and Plant Sciences]
1988
Hansen, J.G. (Statens Planteavlsforsoeg, Foulum (Denmark))
Studies on pollution in the atmosphere near the aluminium reduction plant at Nagi Hammady / Egypt
1990
El-Shazly, S.M. (Faculty of Science in Qena (Egypt). Dept. of Physics, Lab. of Atmospheric Physics) | Abdelmageed, A.M. | Abdelaal, A.
The effects of wet deposition chemistry on reproductive processes in two pine species: apparent pollination effectiveness in relation to species pollen sensitivity
1992
Cox, R.M. (Forestry Canada Maritimes Region, Fredericton, N.B. (Canada). H.J.F. Forestry Centre)
A new method of rainfall-runoff modelling and its applications in catchment hydrology
1994
Littlewood, I.G. | Jakeman, A.J. (Institute of Hydrology, Wallingford, OX10 3BB (United Kingdom))