Dome effect of black carbon and its key influencing factors: a one-dimensional modelling study
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 <q>dome effect</q>. However, the impacts of key factors that in...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/2821/2018/acp-18-2821-2018.pdf |
| Summary: | 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 <q>dome effect</q>. 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. |
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| ISSN: | 1680-7316 1680-7324 |