scholarly journals Influence of aerosol copper on HO<sub>2</sub> uptake: A novel parameterized equation

2020 ◽  
Author(s):  
Huan Song ◽  
Xiaorui Chen ◽  
Keding Lu ◽  
Qi Zou ◽  
Zhaofeng Tan ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Liquid Water Content ◽  
Atmospheric Effects ◽  
Peroxy Radicals ◽  
Model Optimization ◽  
Lab Experiments ◽  
New Equation ◽  
Phase Chemistry ◽  
The Impact

Abstract. The heterogeneous uptake of hydroxyl peroxy radicals (HO2) on aerosol has been proposed to be a significant sink of HOx, thus could influence the atmospheric oxidation capacity. Accurate calculation of the uptake coefficient γHO2 is the key to quantifying its atmospheric effects. Laboratory studies show that γHO2 varies by orders of magnitude due to change in aerosol properties, especially those of aerosol soluble copper (Cu) and aerosol liquid water content (ALWC). In this study, we develop a state-of-the-art model to simulate both gas and aerosol phase chemistry. A novel parameterized equation of HO2 considering change in RH and aerosol Cu is developed based on model optimization toward all available lab experiments. 1 / γ = 1 / α + (3 × v) / (4 × 106 × Rd Hcorr RT × (5.87 + 3.2 × ln(ALWC / [PM] + 0.067)) × [PM]−0.2 × [Cu2+]0.65) According to the new equation, highly variable HO2 uptake coefficients (median value ∼0.1) were diagnosed for North China Plain and the impact of HO2 uptake on the ROx budget is assessed.

scholarly journals Influence of aerosol copper on HO<sub>2</sub> uptake: a novel parameterized equation

2020 ◽  
Vol 20 (24) ◽  
pp. 15835-15850
Author(s):  
Huan Song ◽  
Xiaorui Chen ◽  
Keding Lu ◽  
Qi Zou ◽  
Zhaofeng Tan ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Laboratory Data ◽  
Liquid Water Content ◽  
Model Optimization ◽  
The North ◽  
Potential Impact ◽  
New Equation ◽  
Phase Chemistry ◽  
The Impact

Abstract. Heterogeneous uptake of hydroperoxyl radicals (HO2) onto aerosols has been proposed to be a significant sink of HOx, hence impacting the atmospheric oxidation capacity. Accurate calculation of the HO2 uptake coefficient γHO2 is key to quantifying the potential impact of this atmospheric process. Laboratory studies show that γHO2 can vary by orders of magnitude due to changes in aerosol properties, especially aerosol soluble copper (Cu) concentration and aerosol liquid water content (ALWC). In this study we present a state-of-the-art model called MARK to simulate both gas- and aerosol-phase chemistry for the uptake of HO2 onto Cu-doped aerosols. Moreover, a novel parameterization of HO2 uptake was developed that considers changes in relative humidity (RH) and condensed-phase Cu ion concentrations and which is based on a model optimization using previously published and new laboratory data included in this work. This new parameterization will be applicable to wet aerosols, and it will complement current IUPAC recommendations. The new parameterization is as follows (the explanations for symbols are in the Appendix): 1γHO2=1αHO2+3×υHO24×106×RdHcorrRT×(5.87+3.2×ln⁡(ALWC/[PM]+0.067))×[PM]-0.2×Cu2+eff0.65+υHO2l4RTHorgDorgε. All parameters used in the paper are summarized in Table A1. Using this new equation, field data from a field campaign were used to evaluate the impact of the HO2 uptake onto aerosols on the ROx (= OH + HO2 + RO2) budget. Highly variable values for HO2 uptake were obtained for the North China Plain (median value < 0.1).

scholarly journals Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

2021 ◽  
Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
North China Plain ◽  
North China ◽  
Fine Particles ◽  
Large Fraction ◽  
Organic Aerosol ◽  
Size Distributions ◽  
The North ◽  
The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

scholarly journals Impact of crop field burning and mountains on heavy haze in the North China Plain: A case study

2016 ◽  
Author(s):  
X. Long ◽  
X. X. Tie ◽  
J. J. Cao ◽  
R. J. Huang ◽  
T. Feng ◽  
...  
Keyword(s):  
Air Pollution ◽  
North China Plain ◽  
North China ◽  
Wind Condition ◽  
Beijing City ◽  
The North ◽  
The North China Plain ◽  
Crop Field ◽  
The Impact ◽  
Field Burning

Abstract. Crop field burning (CFB) has important effects on air pollution in China, but it is seldom quantified and reported in a regional scale, which is of great importance for the control strategies of CFB in China, especially in the North China Plain (NCP). With the provincial statistical data and open crop fires captured by satellite (MODIS), we extracted a detailed emission inventory of CFB during a heavy haze event from 6th to 12th October 2014. A regional dynamical and chemical model (WRF-Chem) was applied to investigate the impact of CFB on air pollution in NCP. The model simulations were compared with the in situ measurements of PM2.5 (particular matter with radius less than 2.5 μm) concentrations. The model evaluation shows that the correlation coefficients (R) between measured and calculated values exceeds 0.80 and absolute normalized mean bias (NMB) is no more than 14 %. In addition, the simulated meteorological parameters such as winds and planetary boundary layer height (PBLH) are also in good agreement with observations. The model was intensive used to study (1) the impacts of CFB and (2) the effect of mountains on regional air quality. The results show that the CFB occurred in southern NCP (SNCP) had significant effect on PM2.5 concentrations locally, causing a maximum of 35 % PM2.5 increase in SNCP. Because of south wind condition, the CFB pollution plume is subjective a long transport to northern NCP (NNCP-with several mega cities, including Beijing of the capital city in China), where there are no significant CFB occurrences, causing a maximum of 32 % PM2.5 increase in NNCP. As a result, the heavy haze in Beijing is enhanced by the CFB occurred in SNCP. Further more, there are two major mountains located in the western and northern NCP. Under the south wind condition, these mountains play important roles in enhancing the PM2.5 pollution in NNCP through the blocking and guiding effects. This study suggests that the PM2.5 emissions in SNCP region should be significantly limited in order to reduce the occurrences of heavy haze events in NNCP region, including the Beijing City.

Aerosol chemical compositions in the North China Plain and the impact on the visibility in Beijing and Tianjin

2018 ◽  
Vol 201 ◽  
pp. 235-246 ◽  
Author(s):  
Jianan Zou ◽  
Zirui Liu ◽  
Bo Hu ◽  
Xiaojuan Huang ◽  
Tianxue Wen ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
Chemical Compositions ◽  
The North ◽  
The North China Plain ◽  
The Impact

Impact of the methods of groundwater access on irrigation and crop yield in the North China Plain

2016 ◽  
Vol 8 (4) ◽  
pp. 613-633 ◽  
Author(s):  
Lijuan Zhang ◽  
Jinxia Wang ◽  
Guangsheng Zhang ◽  
Qiuqiong Huang
Keyword(s):  
Crop Yield ◽  
North China Plain ◽  
North China ◽  
Climate Factors ◽  
Groundwater Use ◽  
Content Type ◽  
The North ◽  
The North China Plain ◽  
Groundwater Markets ◽  
The Impact

Purpose The purpose of this paper is: to track the methods by which farmers access groundwater for irrigation in the North China Plain (NCP); to explore whether climate factors influence farmers’ decisions on the methods of groundwater access for irrigation; and to examine whether the amount of groundwater use for irrigation and crop yield systematically differ across groups of farmers using various methods of groundwater access, and how climate factors affect them. Design/methodology/approach Descriptive statistical analysis and econometric models are used on household survey data collected over several years and county-level climate data. Findings Over the past few decades, a significant share of farmers have switched the methods of groundwater access from collective tubewells to own tubewells or groundwater markets. Farmers who bought water from groundwater markets applied less water to wheat plots than those who had their own tubewells. However, wheat yield was not negatively affected. Both average climate conditions and long-term variations were found to be related to farmers’ choice of methods of groundwater access for irrigation. More frequent droughts and increasingly volatile temperatures both increased the likelihood of farmers gaining groundwater irrigation from markets. Originality/value The analysis results suggest farmers are using groundwater markets to help them adapt to climate change. Applying empirical analysis to identify the impact of the methods by which farmers access groundwater for irrigation on the amount of groundwater use and crop yield will help policy makers design reasonable adaptation policies for the NCP.

scholarly journals Study on the Change Characteristics of and Population Exposure to Heatwave Events on the North China Plain

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Long-Fei Zhan ◽  
Yanjun Wang ◽  
Hemin Sun ◽  
Jianqing Zhai ◽  
Mingjin Zhan
Keyword(s):  
North China Plain ◽  
North China ◽  
Climatic Factors ◽  
Demographic Data ◽  
Population Exposure ◽  
Central Position ◽  
Daily Maximum ◽  
The North ◽  
The North China Plain ◽  
The Impact

In accordance with the China Meteorological Administration definition, this study considered a weather process with a maximum surface temperature of ≥35°C for more than three consecutive days as a heatwave event. Based on a dataset of daily maximum temperatures from meteorological stations on the North China Plain, including ordinary and national basic/reference surface stations, the intensity-area-duration method was used to analyze the spatiotemporal distribution characteristics of heatwave events on the North China Plain (1961–2017). Moreover, based on demographic data from the Statistical Yearbook and Greenhouse Gas Initiative (GGI) Population Scenario Database of the Austrian Institute for International Applied Systems Analysis (IIASA), population exposure to heatwave events was also studied. The results showed that the frequency, intensity, and area of impact of heatwave events on the North China Plain initially decreased (becoming weaker and less extensive) and then increased (becoming stronger and more extensive). Similarly, the trend of population exposure to heatwave events initially decreased and then increased, and the central position of exposure initially moved southward and then returned northward. Population exposure in the eastern Taihang Mountains was found significantly higher than in the western Taihang Mountains. In relation to the change of population exposure to heatwave events on the North China Plain, the influence of climatic factors was found dominant with an absolute contribution rate of >75%. Except for 2011–2017, increase in population also increased the exposure to heatwaves, particularly in the first half of the study period. Interaction between climatic and population factors generally had less impact on population exposure than either climatic factors or population factors alone. This study demonstrated a method for assessing the impact of heatwave events on population exposure, which could form a scientific basis for the development of government policy regarding adaption to climate change.

scholarly journals Observation of atmospheric peroxides during Wangdu Campaign 2014 at a rural site in the North China Plain

2016 ◽  
Vol 16 (17) ◽  
pp. 10985-11000 ◽  
Author(s):  
Yin Wang ◽  
Zhongming Chen ◽  
Qinqin Wu ◽  
Hao Liang ◽  
Liubin Huang ◽  
...  
Keyword(s):  
Biomass Burning ◽  
North China Plain ◽  
North China ◽  
Chemical Mechanism ◽  
Rural Site ◽  
Direct Production ◽  
The North ◽  
The North China Plain ◽  
The Impact ◽  
Haze Days

Abstract. Measurements of atmospheric peroxides were made during Wangdu Campaign 2014 at Wangdu, a rural site in the North China Plain (NCP) in summer 2014. The predominant peroxides were detected to be hydrogen peroxide (H2O2), methyl hydroperoxide (MHP) and peroxyacetic acid (PAA). The observed H2O2 reached up to 11.3 ppbv, which was the highest value compared with previous observations in China at summer time. A box model simulation based on the Master Chemical Mechanism and constrained by the simultaneous observations of physical parameters and chemical species was performed to explore the chemical budget of atmospheric peroxides. Photochemical oxidation of alkenes was found to be the major secondary formation pathway of atmospheric peroxides, while contributions from alkanes and aromatics were of minor importance. The comparison of modeled and measured peroxide concentrations revealed an underestimation during biomass burning events and an overestimation on haze days, which were ascribed to the direct production of peroxides from biomass burning and the heterogeneous uptake of peroxides by aerosols, respectively. The strengths of the primary emissions from biomass burning were on the same order of the known secondary production rates of atmospheric peroxides during the biomass burning events. The heterogeneous process on aerosol particles was suggested to be the predominant sink for atmospheric peroxides. The atmospheric lifetime of peroxides on haze days in summer in the NCP was about 2–3 h, which is in good agreement with the laboratory studies. Further comprehensive investigations are necessary to better understand the impact of biomass burning and heterogeneous uptake on the concentration of peroxides in the atmosphere.

scholarly journals A study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain

2014 ◽  
Vol 14 (12) ◽  
pp. 6417-6426 ◽  
Author(s):  
Y. X. Bian ◽  
C. S. Zhao ◽  
N. Ma ◽  
J. Chen ◽  
W. Y. Xu
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Liquid Water ◽  
North China Plain ◽  
North China ◽  
Liquid Water Content ◽  
High Relative Humidity ◽  
The North ◽  
The North China Plain ◽  
Thermodynamic Equilibrium Model

Abstract. Water can be a major component of aerosol particles, also serving as a medium for aqueous-phase reactions. In this study, a novel method is presented to calculate the aerosol liquid water content at high relative humidity based on measurements of aerosol hygroscopic growth factor, particle number size distribution and relative humidity in the Haze in China (HaChi) summer field campaign (July–August 2009) in the North China Plain. The aerosol liquid water content calculated using this method agreed well with that calculated using a thermodynamic equilibrium model (ISORROPIA II) at high relative humidity (>60%) with a correlation coefficient of 0.96. At low relative humidity (<60%), an underestimation was found in the calculated aerosol liquid water content by the thermodynamic equilibrium model. This discrepancy mainly resulted from the ISORROPIA II model, which only considered limited aerosol chemical compositions. The mean and maximum values of aerosol liquid water content during the HaChi campaign reached 1.69 × 10−4 g m−3 and 9.71 × 10−4 g m−3, respectively. A distinct diurnal variation of the aerosol liquid water content was found, with lower values during daytime and higher ones at night. The aerosol liquid water content depended strongly on the relative humidity. The aerosol liquid water content in the accumulation mode dominated the total aerosol liquid water content.

Assessment of the impact of emissions reductions on air quality over North China Plain

2016 ◽  
Vol 7 (2) ◽  
pp. 249-259 ◽  
Author(s):  
Xiao Han ◽  
Meigen Zhang ◽  
Lingyun Zhu ◽  
Andrei Skorokhod
Keyword(s):  
Air Quality ◽  
North China Plain ◽  
North China ◽  
Emissions Reductions ◽  
The Impact

scholarly journals A~study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain

2014 ◽  
Vol 14 (3) ◽  
pp. 4089-4118
Author(s):  
Y. X. Bian ◽  
C. S. Zhao ◽  
N. Ma ◽  
J. Chen ◽  
W. Y. Xu
Keyword(s):  
Relative Humidity ◽  
Water Content ◽  
Liquid Water ◽  
North China Plain ◽  
North China ◽  
Liquid Water Content ◽  
High Relative Humidity ◽  
The North ◽  
The North China Plain ◽  
Thermodynamic Equilibrium Model

Abstract. Water can be a major component of an aerosol particle. Also water serves as a medium for aqueous-phase reactions in aerosols. In this study, a novel method is presented to calculate the aerosol liquid water content at high relative humidity based on measurements of aerosol hygroscopic growth factor, particle number size distribution and relative humidity in the Haze in China (HaChi) summer field campaign (July–August 2009) in the North China Plain. The aerosol liquid water content calculated using this method agreed well with that calculated using a thermodynamic equilibrium model (ISORROPIA II) at high relative humidity (>60 %) with a correlation coefficient of 0.9658. At low relative humidity (<60%), an underestimation was found in the calculated aerosol liquid water content by the thermodynamic equilibrium model. This discrepancy mainly resulted from the ISORROPIA II model, which only considered limited aerosol chemical compositions. The mean and maximum values of aerosol liquid water content during the HaChi campaign reached 1.69 × 10−4; g m−3 and 9.71 × 10−4; g m−3, respectively. A distinct diurnal variation of the aerosol liquid water content was found, with lower values during daytime and higher ones at night. The aerosol liquid water content depended strongly on the relative humidity. The aerosol liquid water content in the accumulation mode dominated the total aerosol liquid water content.

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