scholarly journals Referee comment on "Secondary aerosol formation alters CCN activity in the North China Plain"

2020 ◽  
Author(s):  
Anonymous
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
The North ◽  
The North China Plain ◽  
Ccn Activity

scholarly journals Explosive Secondary Aerosol Formation during Severe Haze in the North China Plain

2021 ◽  
Vol 55 (4) ◽  
pp. 2189-2207
Author(s):  
Jianfei Peng ◽  
Min Hu ◽  
Dongjie Shang ◽  
Zhijun Wu ◽  
Zhuofei Du ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
The North ◽  
The North China Plain

scholarly journals Role of Ammonia on the Feedback Between AWC and Inorganic Aerosol Formation During Heavy Pollution in the North China Plain

2019 ◽  
Vol 6 (9) ◽  
pp. 1675-1693 ◽  
Author(s):  
Baozhu Ge ◽  
Xiaobin Xu ◽  
Zhiqiang Ma ◽  
Xiaole Pan ◽  
Zhe Wang ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Formation ◽  
The North ◽  
The North China Plain ◽  
Heavy Pollution ◽  
Inorganic Aerosol

Explosive morning growth phenomena of NH3 on the North China Plain: Causes and potential impacts on aerosol formation

2020 ◽  
Vol 257 ◽  
pp. 113621 ◽  
Author(s):  
Ye Kuang ◽  
Wanyun Xu ◽  
Weili Lin ◽  
Zhaoyang Meng ◽  
Huarong Zhao ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Aerosol Formation ◽  
The North ◽  
The North China Plain

Secondary aerosol formation alters CCN activity in the North China Plain

2021 ◽  
Author(s):  
Jiangchuan Tao ◽  
Ye Kuang ◽  
Nan Ma ◽  
Juan Hong ◽  
Yele Sun ◽  
...  
Keyword(s):  
Particle Size ◽  
North China Plain ◽  
North China ◽  
Particle Mass ◽  
Mixing State ◽  
Particle Size Range ◽  
The North ◽  
The North China Plain ◽  
Aerosol Mixing State ◽  
Ccn Activity

<p>The formation of secondary aerosols (SA, including secondary organic and inorganic aerosols, SOA and SIA) were the dominant sources of aerosol particles in the North China Plain and can result in significant variations of particle size distribution (PNSD) and hygroscopicity. Earlier studies have shown that the mechanism of SA formation can be affected by relative humidity (RH), and thus has different influences on the aerosol hygroscopicity and PNSD under different RH conditions. Based on the measurements of size-resolved particle activation ratio (SPAR), hygroscopicity distribution (GF-PDF), PM<sub>2.5</sub> chemical composition, PNSD, meteorology and gaseous pollutants in a recent field campaign McFAN (Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain) conducted at Gucheng site from November 16<sup>th</sup> to December 16<sup>th</sup> in 2018, the influences of SA formation on CCN activity and CCN number concentration (N<sub>CCN</sub>) calculation at super-saturation of 0.05% under different RH conditions were studied. Measurements showed that during daytime, SA formation could lead to a significant increase in N<sub>CCN</sub> and a strong diurnal variation in CCN activity. During periods with daytime minimum RH exceeding 50% (high RH conditions), SA formation significantly contributed to the particle mass/size changes in wide particle size range of 150 nm to 1000 nm, and led to an increase of N<sub>CCN</sub> in particle size range of 200 nm to 300 nm, while increases in particle mass concentration mainly occurred within particle sizes larger than 300nm. During periods with daytime minimum RH below 30% in (low RH conditions), SA formation mainly contributed to the particle mass/size and N<sub>CCN</sub> changes in particle sizes smaller than 300 nm. As a result, under the same amount SA formation induced mass increase, the increase of N<sub>CCN</sub> was weaker under high RH conditions, while stronger under low RH conditions. Moreover, the diurnal variations of aerosol mixing state (inferred from CCN measurements) due to SA formation was different under different RH conditions. If the variations of the aerosol mixing state were not considered, estimations of N<sub>CCN</sub> would bear significant deviations. By applying aerosol mixing state estimated by number fraction of hygroscopic particles from measurements of particle hygroscopicity or mass fraction of SA from measurements of particle chemical compositions, N<sub>CCN</sub> calculation can be largely improved with relative deviation within 30%. This study improves the understanding of the impact of SA formation on CCN activity and N<sub>CCN</sub> calculation, which is of great significance for improving parameterization of SA formation in aerosol models and CCN calculation in climate models.</p>

scholarly journals Contribution of hydroxymethanesulfonate (HMS) to severe winter haze in the North China Plain

2020 ◽  
Author(s):  
Tao Ma ◽  
Hiroshi Furutani ◽  
Fengkui Duan ◽  
Takashi Kimoto ◽  
Jingkun Jiang ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
North China Plain ◽  
North China ◽  
Molar Ratio ◽  
Formation Mechanisms ◽  
Aerosol Formation ◽  
Severe Winter ◽  
The North ◽  
The North China Plain ◽  
High Concentrations

Abstract. Severe winter hazes accompanied by high concentrations of fine particulate matter (PM2.5) occur frequently in the North China Plain and threaten public health. Organic matter (OM) and sulfate are recognized as major components of PM2.5, while atmospheric models often fail to predict their high concentrations during severe winter hazes due to incomplete understanding of secondary aerosol formation mechanisms. By using a novel combination of single particle mass spectrometer and optimized ion chromatography measurement, here we show that hydroxymethanesulfonate (HMS), formed by the reaction between formaldehyde (HCHO) and dissolved SO2 in aerosol water, is ubiquitous in Beijing winter. The HMS concentration and the molar ratio of HMS to sulfate increased with the deterioration of winter haze. High concentrations of precursors (SO2 and HCHO) coupled with low oxidant levels, low temperature, high relative humidity, and moderately acid pH facilitate the heterogeneous formation of HMS, which could account for up to 15 % of OM in winter haze and lead to 36 % overestimates of sulfate when using traditional ion chromatography measurements. Despite the clean air actions have substantially reduced SO2 emissions, HMS concentration and molar ratio of HMS to sulfate during severe winter hazes increased from 2015 to 2016 with the growth of HCHO concentration. Our findings illustrate the significant contribution of heterogeneous HMS chemistry to severe winter hazes in Beijing, which help to improve the prediction of OM and sulfate, and suggest that the reduction in HCHO can help to mitigate haze pollution.

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