Simulated impacts of direct radiative effects of scattering and absorbing aerosols on surface layer aerosol concentrations in China during a heavily polluted event in February 2014

Abstract

We quantified aerosol direct radiative effects on surface layer concentrations of aerosols during a heavily polluted event in the North China Plain (NCP, 35.4°N–41.2°N, 113.3°E–119.3°E) during 21–27 February 2014, using the chemistry version of the Weather Research and Forecasting (WRF‐Chem) Model. Comparisons of model results with observations showed that the WRF‐Chem model reproduced the spatial and temporal variations of meteorological variables reasonably well, but overestimated average PM2.5 concentration by 21.7% over the NCP during 21–27 February. The simulated direct radiative effects of total, absorbing, and scattering aerosols reduced the planetary boundary layer (PBL) heights by 111.4 m, 35.7 m, and 70.7 m, respectively, averaged over NCP and 21–27 February. The direct radiative effects of total aerosols induced increases in aerosol concentrations by 11.5% for SO42−, 29.5% for NO3−, 29.6% for NH4+, 28.7% for organic carbon (OC), 26.7% for black carbon (BC), and 20.4% for PM2.5, respectively, averaged over the NCP during 21–27 February 2014. The increase in PM2.5 concentration averaged over the NCP and the haze event was 29.6 μg m−3 (16.8%) due to radiative effect of scattering aerosols, as a result of the decreases in PBL height and changes in secondary aerosol production rates. The corresponding increase in PM2.5 concentration owing to absorbing aerosols was 2.1 μg m−3 (1.0%), resulting from the offsetting impacts of changes in PBL height, wind near the surface, and chemical processes.

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

“…As shown, the index values were correlated very well with daytime PM 2.5 concentration with the Pearson's correlation coefficient (R) as high as 0.56, indicating that higher concentration of PM 2.5 coincided with more substantial temperature bias in reanalysis data. Some existing studies suspected that extremely high loading of scattering aerosols may play the dominate role in enhancing PBL stability through backscattering solar radiation (Qiu et al, ). However, quite good linear negative relationship of surface dimming and overall upper‐level heating shown in Figure S6 provided an important observational clue to the significance of light‐absorbing aerosols, so did previous shortwave radiation budget studies (Huang et al, ; Ramanathan & Carmichael, ).…”

The impact of aerosol–radiation interactions on the effectiveness of emission control measures

“…Aerosols can directly scatter or absorb solar radiation (Hansen et al 1997), leading to perturbations in the energy budget (Ramanathan et al 2001), which is defined as aerosol-radiation interactions (ARI hereafter). Both scattering and absorbing aerosols can increase atmospheric stability (Qiu et al 2017). In addition, aerosols can serve as sources of cloud condensation nucleus, altering cloud lifetime Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.…”

“…Both ARI and ACI can alter the lapse rate and vertical mixing of mass and momentum in the planetary boundary layer (PBL) (Yang et al 2016), and perturb meteorological variables such as surface temperature, relative humidity (RH), wind, and PBL height (PBLH) (Gao et al 2015). Consequently, these perturbations affect PM 2.5 concentrations via changes in transport and chemical formation (Yang et al 2015, Zhang et al 2015b, Chen et al 2016, Qiu et al 2017, Li et al 2017a .…”

Influence of Black Carbon Aerosol on the Atmospheric Instability

“…Several researchers mentioned about the processes of aerosol-cloud interaction in climate models that still exist as an important source of uncertainty (Fan et al, 2013;Sarna & Russchenberg, 2017). In addition to this, aerosols and their association with the stability of the lower atmosphere increases the regional uncertainties (Qiu et al, 2017). Recent studies reveal that the heating efficiency of absorbing aerosol is more in the upper boundary layer compared to lower boundary layer height (Ding et al, 2016;Wang et al, 2018).…”