Dome effect of black carbon and its key influencing factors: a one-dimensional modelling study

Abstract

Abstract. Black carbon (BC) has been identified to play a critical role in aerosol–planetary boundary layer (PBL) interaction and further deterioration of near-surface air pollution in megacities, which has been referred to as the “dome effect”. However, the impacts of key factors that influence this effect, such as the vertical distribution and aging processes of BC, as well as the underlying land surface, have not been quantitatively explored yet. Here, based on available in situ measurements of meteorology and atmospheric aerosols together with the meteorology–chemistry online coupled model WRF-Chem, we conduct a set of parallel simulations to quantify the roles of these factors in influencing the BC dome effect and surface haze pollution. Furthermore, we discuss the main implications of the results to air pollution mitigation in China. We found that the impact of BC on the PBL is very sensitive to the altitude of aerosol layer. The upper-level BC, especially that near the capping inversion, is more essential in suppressing the PBL height and weakening the turbulent mixing. The dome effect of BC tends to be significantly intensified as BC mixed with scattering aerosols during winter haze events, resulting in a decrease in PBL height by more than 15 %. In addition, the dome effect is more substantial (up to 15 %) in rural areas than that in the urban areas with the same BC loading, indicating an unexpected regional impact of such an effect to air quality in countryside. This study indicates that China's regional air pollution would greatly benefit from BC emission reductions, especially those from elevated sources from chimneys and also domestic combustion in rural areas, through weakening the aerosol–boundary layer interactions that are triggered by BC.

Impact of Aerosol‐PBL Interaction on Haze Pollution: Multiyear Observational Evidences in North China

“…Aerosols in the atmosphere could directly or indirectly influence the radiation balance of the Earthatmosphere system and hence regional or global climate change (Ackerman et al, 2004;Bond et al, 2013;Boucher et al, 2013;Menon et al, 2002). Recent studies have found that the impact of aerosols, particularly absorption aerosols like black carbon (BC) and dusts, to solar radiation is also important to the development of planetary boundary layer (PBL) and the air quality within the PBL Liu et al, 2016;Z. Wang et al, 2018;Wilcox et al, 2016;Yang, Russell, et al, 2017).…”

“…Li, Guo, et al, 2017;Petäjä et al, 2016;Quan et al, 2013). Second, the solar absorption aerosols in the atmosphere could heat the atmosphere by trapping solar energy and result in strong heating in upper PBL or around the PBL top, which change the vertical temperature stratification and further suppress the development of PBL Z. Wang et al, 2018).…”

“…Due to tremendous anthropogenic emission, the North China has been suffering from heavy haze pollution in cold seasons (Z. Wang et al, 2018;Zhang et al, 2016). Extremely high concentration of scattering and absorption aerosols have been observed frequently in this region in winter, especially in megacities like Beijing.…”

Transport, mixing, and feedback of dust, biomass burning and anthropogenic pollutants in eastern Asia: A case study

“…2016), which efficiently heated the surrounding air near 8 km. Previous modelling and observation studies has emphasized the importance of upper-air aerosols in changing temperature stratification because of more incident solar radiation and less efficient vertical heat exchange (Samset et al, 2014;Wang et al, 2018). In this case, BB and dust aloft caused by frontal system were expected to exert important role in changing the air temperature in MLT.…”

“…CC BY 4.0 License. radiative feedback (Hansen et al, 1997;Li et al, 2011;IPCC, 2013;.Our previous works found how the air pollution-boundary layer feedback changed the weather and in turn how the modified meteorological conditions enhanced the accumulation of air pollution (Ding et al, 2013a;Liu et al, 2016;Ding et al, 2017;Wang et al, 2018).…”