scholarly journals Evaluation and Bias Correction of the Secondary Inorganic Aerosol Modeling over North China Plain in Autumn and Winter

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 578
Author(s):  
Qian Wu ◽  
Xiao Tang ◽  
Lei Kong ◽  
Xu Dao ◽  
Miaomiao Lu ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Heterogeneous Reaction ◽  
Winter Season ◽  
Uptake Coefficient ◽  
Anthropogenic Aerosols ◽  
Heterogeneous Chemical Reaction ◽  
Heterogeneous Chemical ◽  
Inorganic Aerosol ◽  
Aerosol Modeling

Secondary inorganic aerosol (SIA) is the key driving factor of fine-particle explosive growth (FPEG) events, which are frequently observed in North China Plain. However, the SIA simulations remain highly uncertain over East Asia. To further investigate this issue, SIA modeling over North China Plain with the 15 km resolution Nested Air Quality Prediction Model System (NAQPMS) was performed from October 2017 to March 2018. Surface observations of SIA at 28 sites were obtained to evaluate the model, which confirmed the biases in the SIA modeling. To identify the source of these biases and reduce them, uncertainty analysis was performed by evaluating the heterogeneous chemical reactions in the model and conducting sensitivity tests on the different reactions. The results suggest that the omission of the SO2 heterogeneous chemical reaction involving anthropogenic aerosols in the model is probably the key reason for the systematic underestimation of sulfate during the winter season. The uptake coefficient of the “renoxification” reaction is a key source of uncertainty in nitrate simulations, and it is likely to be overestimated by the NAQPMS. Consideration of the SO2 heterogeneous reaction involving anthropogenic aerosols and optimization of the uptake coefficient of the “renoxification” reaction in the model suitably reproduced the temporal and spatial variations in sulfate, nitrate and ammonium over North China Plain. The biases in the simulations of sulfate, nitrate, ammonium, and particulate matter smaller than 2.5 μm (PM2.5) were reduced by 84.2%, 54.8%, 81.8%, and 80.9%, respectively. The results of this study provide a reference for the reduction in the model bias of SIA and PM2.5 and improvement of the simulation of heterogeneous chemical processes.

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

Seasonal effects of additional HONO sources and the heterogeneous reactions of N2O5 on nitrate in the North China Plain

2020 ◽  
Author(s):  
Yu Qu ◽  
Junling An
Keyword(s):  
North China Plain ◽  
North China ◽  
Heterogeneous Reaction ◽  
Heterogeneous Reactions ◽  
Seasonal Effects ◽  
Weather Research And Forecasting ◽  
The North ◽  
The North China Plain ◽  
Four Seasons ◽  
Hydrolysis Of

<p>We coupled the heterogeneous hydrolysis of N<sub>2</sub>O<sub>5</sub> into the newly updated Weather Research and Forecasting model with Chemistry (WRF-Chem) to reveal the relative importance of the hydrolysis of N<sub>2</sub>O<sub>5</sub> and additional nitrous acid (HONO) sources for the formation of nitrate during high PM<sub>2.5</sub> events in the North China Plain (NCP) in four seasons. The results showed that additional HONO sources produced the largest nitrate concentrations in winter and negligible nitrates in summer, leading to a 10% enhancement of a PM<sub>2.5</sub> peak in southern Beijing and a 15% enhancement in southeastern Hebei in winter. In contrast, the hydrolysis of N<sub>2</sub>O<sub>5</sub> produced high nitrate in summer and low nitrate in winter, with the largest contribution of nearly 20% for a PM<sub>2.5</sub> peak in southeastern Hebei in summer. During PM<sub>2.5 </sub>explosive growth events, the additional HONO sources played a key role in nitrate increases in southern Beijing and southwestern Hebei in winter, whereas the hydrolysis of N<sub>2</sub>O<sub>5 </sub>contributed the most to a rapid increase in nitrate in other seasons. HONO photolysis produced more hydroxyl radicals, which were greater than 1.5 μg m<sup>-3</sup> h<sup>-1</sup> in the early explosive stage and led to a rapid nitrate increase at the southwestern Hebei sites in winter, while the heterogeneous reaction of N<sub>2</sub>O<sub>5</sub> contributed greatly to a significant increase in nitrate in summer. The above results suggest that the additional HONO sources and the heterogeneous hydrolysis of N<sub>2</sub>O<sub>5</sub> contributed the most to nitrate formation in NCP in winter and summer, respectively.</p>

scholarly journals Amplified role of potential HONO sources in O<sub>3</sub> formation in North China Plain during autumn haze aggravating processes

2021 ◽  
Author(s):  
Jingwei Zhang ◽  
Chaofan Lian ◽  
Weigang Wang ◽  
Maofa Ge ◽  
Yitian Guo ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Heterogeneous Reaction ◽  
Ground Surface ◽  
Field Studies ◽  
Daily Maximum ◽  
Pollution Levels ◽  
The North ◽  
Order Of Magnitude ◽  
High Concentrations

Abstract. Co-occurrences of high concentrations of PM2.5 and ozone (O3) have been frequently observed in haze aggravating processes in the North China Plain (NCP) over the past few years, and higher O3 concentrations during hazy days were supposed to be related to nitrous acid (HONO), but the key sources of HONO enhancing O3 during haze aggravating processes remain unclear, and will be explored in this study by using the WRF-Chem model, which is improved to include ground-based (traffic, soil, and indoor emissions, and the NO2 heterogeneous reaction on ground surface (Hetground)) and aerosol-related (the NO2 heterogeneous reaction on aerosol surfaces (Hetaerosol) and nitrate photolysis (Photnitrate)) potential HONO sources. The results indicate that ground-based HONO sources producing HONO enhancements showed a rapid decrease with height, while the NO+OH reaction and aerosol-related HONO sources decreased slowly with height. Photnitrate contributions to HONO concentrations enhanced with aggravated pollution levels, the enhanced HONO due to Photnitrate in hazy days was about one order of magnitude larger than in clean days and Photnitrate dominated HONO sources (~30–70 % when the ratio of the photolysis frequency of nitrate (Jnitrate) to gas nitric acid (JHNO3) equals 30) at higher layers (> 800 m). Compared with that in clean days, the Photnitrate contribution to the enhanced daily maximum 8-h averaged O3 was increased by over one magnitude during the haze aggravating process. Photnitrate contributed only ~5 % of the surface HONO in daytime with a Jnitrate/JHNO3 ratio of 30 but contributed ~30–50 % of the enhanced O3 near the surface in NCP in hazy days. Surface O3 was dominated by volatile organic compounds-sensitive chemistry, while O3 at higher altitude (> 800 m) was dominated by NOx-sensitive chemistry. Photnitrate had a limited impact on nitrate concentrations (< 15 %) even with a Jnitrate/JHNO3 ratio of 120. The above results suggest that more field studies of Jnitrate in the atmosphere are still needed.

scholarly journals Serious BTEX pollution in rural area of the North China Plain during winter season

2015 ◽  
Vol 30 ◽  
pp. 186-190 ◽  
Author(s):  
Kankan Liu ◽  
Chenglong Zhang ◽  
Ye Cheng ◽  
Chengtang Liu ◽  
Hongxing Zhang ◽  
...  
Keyword(s):  
Rural Area ◽  
North China Plain ◽  
North China ◽  
Winter Season ◽  
The North ◽  
The North China Plain

scholarly journals Impacts of anthropogenic aerosols on fog in North China Plain

2018 ◽  
Author(s):  
Xingcan Jia ◽  
Jiannong Quan ◽  
Ziyan Zheng ◽  
Xiange Liu ◽  
Quan Liu ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Anthropogenic Aerosols

McFAN experiment: An integrated analysis of the multiphase chemistry experiment in Fogs and Aerosols in the North China Plain

2020 ◽  
Author(s):  
Hang Su ◽  
Nan Ma ◽  
Yele Sun ◽  
Jiangchuan Tao ◽  
Pingqing Fu ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Winter Season ◽  
Direct Determination ◽  
Organic Aerosol ◽  
Integrated Analysis ◽  
The North ◽  
The North China Plain ◽  
The Impact ◽  
Chemistry Experiment

&lt;p&gt;Fine-particle pollution associated with winter haze threatens the health of more than 400 million people in the North China Plain. The Multiphase chemistry experiment in Fogs and Aerosols in the North China Plain (McFAN) investigated the physical-chemical mechanisms leading to the haze formation with a focus on the contributions of multiphase processes in aerosol and fogs. We integrated multiple platform observations with regional and box models to identify the key oxidation process producing sulfate, nitrate and secondary organic aerosols, and their impact. A new environmental chamber was deployed to conduct kinetic experiments with real atmospheric compositions in comparison to literature kinetic data from laboratory studies. The experiments were carried out for multiple years since 2017 at the Gucheng site in the center of polluted areas and have performed experiments in the winter season. The location of the site minimizes fast transition between clean and polluted air masses (e.g., in Beijing), and helps to maintain a pollution regime representative for the North China Plain. The multi-year consecutive experiments documented the trend of PM2.5 pollution and corresponding change of aerosol physical and chemical properties, and allowed to investigate newly proposed mechanisms. The preliminary results show new proofs of the key role of aqueous phase reactions in regulating the aerosol compositions during haze events.&lt;/p&gt;&lt;p&gt;Reference:&lt;/p&gt;&lt;p&gt;Zheng et al., Exploring the severe winter haze in Beijing: the impact of synoptic weather, regional transport and heterogeneous reactions. Atmospheric Chemistry and Physics &lt;strong&gt;15&lt;/strong&gt;, 2969-2983 (2015).&lt;/p&gt;&lt;p&gt;Cheng et al., Reactive nitrogen chemistry in aerosol water as a source of sulfate during haze events in China. Science Advances &lt;strong&gt;2&lt;/strong&gt;,&amp;#160; (2016).&lt;/p&gt;&lt;p&gt;Li et al., Multifactor colorimetric analysis on pH-indicator papers: an optimized approach for direct determination of ambient aerosol pH. Atmos. Meas. Tech. Discuss. &lt;strong&gt;2019&lt;/strong&gt;, 1-19 (2019).&lt;/p&gt;&lt;p&gt;Kuang et al., Distinct diurnal variation of organic aerosol hygroscopicity and its relationship with oxygenated organic aerosol. Atmos. Chem. Phys. Discuss. &lt;strong&gt;2019&lt;/strong&gt;, 1-33 (2019).&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Turbulent plumes with heterogeneous chemical reaction on the surface of small buoyant droplets

2009 ◽  
Vol 642 ◽  
pp. 49-77 ◽  
Author(s):  
SILVANA S. S. CARDOSO ◽  
SEAN T. MCHUGH
Keyword(s):  
Chemical Reaction ◽  
Heterogeneous Reaction ◽  
Continuous Phase ◽  
Buoyancy Flux ◽  
Buoyancy Frequency ◽  
Heterogeneous Chemical Reaction ◽  
Neutral Buoyancy ◽  
Acidic Aqueous Solution ◽  
Irreversible Reaction ◽  
Heterogeneous Chemical

A model is developed for a turbulent plume with heterogeneous chemical reaction rising in an unbounded environment. The chemical reaction, which may generate or deplete buoyancy in the plume, occurs at the interface between two phases, a continuous phase and a dispersed one. We study the case in which a buoyant reactant is released at the source and forms the dispersed phase, consisting of very small bubbles, droplets or particles. Once in contact with the ambient fluid, a first-order irreversible reaction takes place at the surface of the, for example, droplets. The behaviour of this plume in a uniform and stratified environment is examined. We show that the dynamics of a pure plume with such heterogeneous reaction is completely determined by the ratio of the environmental buoyancy frequency N and a frequency parameter associated with the chemical reaction, G. The group G is a measure of the ability of the reaction to generate buoyancy in the plume. In a uniform environment, the sign of parameter G fully determines the plume motion. When the reaction generates buoyancy (positive G) the motion is unbounded, whilst when reaction depletes buoyancy (negative G) the plume reaches a level of neutral buoyancy. A relation for this neutral buoyancy level as a function of the initial buoyancy flux of the plume and G is calculated. Our theoretical predictions compared well with experimental results using a plume of calcium carbonate particles descending in an acidic aqueous solution. In a stratified environment, the motion of the plume is always bounded, irrespective of the magnitude of G, and we determine the level of maximum buoyancy flux, as well as those of zero buoyancy and zero momentum as a function of N/G. Finally, our model is applied to study the dynamics of a localized release of carbon dioxide in the ocean.

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