Identifying the impact of aerosol-PBL interaction on haze pollution (2016)


As a radiatively important aerosol component in the atmosphere, black carbon (BC) has been identified to play a key role in the aerosol-PBL feedback based on various field observations and model simulations. Ding et al. (2016) demonstrate that BC induces cooling effect along with other scattering aerosols around surface and upper PBL heating which constrains the daytime development of PBL due to deficient surface heat flux and stable atmospheric stratification (Figure 1). Such kind of effect has been named as the dome effect and could substantially enhance near-surface haze pollution in megacities (Ding et al., 2016). The theoretical derivation of this feedback is presented in their joint work (Petäjä et al. 2016).

Figure 1 Aerosol-PBL feedback loop for the scenarios without and with BC emission in a megacity. Black lines show the vertical profile of air temperature (solid, dash-dotted and dotted lines for the scenarios with BC, with aerosols except for BC and without aerosols, respectively). Yellow dashed arrows show the reflection of solar ration by the ground surface, clouds, and scattering aerosols. Red arrows show the absorption of solar radiation by absorbing aerosols like BC and BrC. The blue dash-dotted line indicates the top of PBL. White arrows indicate the vertical ventilation of urban plumes induced by circulations or large eddies induced by the urban heat island effect. The difference in the color of urban plumes means different chemical compositions: the case on the right has more BC (or BrC) from sources like biomass burning, industry, and diesel vehicles, along with more aged air in the upper PBL.

  Ding, A. J., Huang, X., Nie, W., Sun, J. N., Kerminen, V. M., Petäjä, T., Su, H., Cheng, Y. F., Yang, X. Q., Wang, M. H., Chi, X. G., Wang, J. P., Virkkula, A., Guo, W. D., Yuan, J., Wang, S. Y., Zhang, R. J., Wu, Y. F., Song, Y., Zhu, T., Zilitinkevich, S., Kulmala, M., and Fu, C. B.: Enhanced haze pollution by black carbon in megacities in China, Geophysical Research Letters, 43, 2873-2879, 10.1002/2016gl067745, 2016.

  Petäjä, T., Järvi, L., Kerminen, V.-M., Ding, A., Sun, J., Nie, W., Kujansuu, J., Virkkula, A., Yang, X., Fu, C., Zilitinkevich, S. and Kulmala, M. (2016) Enhanced air pollution via aerosol-boundary layer feedback in China, Sci. Rep. 6, 18998, doi: 10.1038/srep18998.