Improved Inversion of Monthly Ammonia Emissions in China Based on the Chinese Ammonia Monitoring Network and Ensemble Kalman Filter

Kong, Lei; Tang, Xiao; Zhu, Jiang; Wang, Zifa; Pan, Yuepeng; Wu, Huangjian; Wu, Lin; Wu, Qizhong; He, Yuexin; Tian, Shili; Xie, Yuzhu; Liu, Zirui; Sui, Wenxuan; Han, Liping; Carmichael, G. R.

doi:10.1021/acs.est.9b02701

Cited by 94 publications

(80 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An inverse study found that the MEIC inventory underestimated NH3 emissions by 30% nationally and by > 40% in eastern and central regions using observations over the same time period as our study (Kong et al, 2019). HiNH3 increases the anthropogenic emissions of NH3 in MEIC by 50%.…”

Section: Sensitivity Simulationssupporting

confidence: 56%

“…SO2, HCHO, and NH3 emissions may influence the modeled HMS. Recent studies have shown, although SO2 emissions are well understood, that there may be large uncertainties in emissions of NH3 and HCHO in China (Pan et al, 2018;Kong et al, 2019;Liu et al, 2019;Song et al, 2019a).…”

Section: Sensitivity Simulationsmentioning

confidence: 99%

“…HiFA increases HCHO emissions from the transportation and residential sectors by a factor of 5. Chemical transport models commonly underestimate SO 4 2− during winter haze episodes in China, and thus some studies have adopted an apparent heterogeneous parameterization for SO2 reactive uptake in order to compensate for the missing SO 4 2− (Zheng et al, 2015;Cheng et al, 2016;Wang et al, 2016;Liu et al, 2019;Li et al, 2020).…”

Section: Sensitivity Simulationsmentioning

confidence: 99%

See 2 more Smart Citations

Global modeling of heterogeneous hydroxymethanesulfonate chemistry

Song¹,

Ma²,

Zhang³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Hydroxymethanesulfonate (HMS) has recently been identified as an abundant organosulfur compound in aerosols during winter haze episodes in northern China. It has also been detected in other regions, although the concentrations are low. Because of the sparse field measurements, the global significance of HMS and its spatial and seasonal patterns remain unclear. Here, we implement HMS chemistry into the GEOS-Chem chemical transport model and conduct multiple global simulations. The developed model accounts for cloud entrainment and gas–aqueous mass transfer within the rate expressions for heterogeneous sulfur chemistry. Our simulations can generally reproduce the available HMS observations, and show that East Asia has the highest HMS concentration, followed by Europe and North America. The simulated HMS shows a seasonal pattern with higher values in the colder period. Photochemical oxidizing capacity affects the competition of formaldehyde with oxidants (such as ozone and hydrogen peroxide) for sulfur dioxide and is a key factor influencing the seasonality of HMS. The highest average HMS concentration (1–3 μg m−3) and HMS/sulfate molar ratio (0.1–0.2) are found in northern China winter. The simulations suggest that aqueous clouds act as the major medium for HMS chemistry while aerosol liquid water may play a role if its rate constant for HMS formation is greatly enhanced compared to cloud water.

show abstract

Section: Sensitivity Simulationssupporting

confidence: 56%

Section: Sensitivity Simulationsmentioning

confidence: 99%

Section: Sensitivity Simulationsmentioning

confidence: 99%

See 1 more Smart Citation

Global modeling of heterogeneous hydroxymethanesulfonate chemistry

Song¹,

Ma²,

Zhang³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…However, depending on the aerosol pH and pollutant compositions, the major multiphase oxidation pathways may change from reactions of NO 2 and O 3 at pH greater than 4.5 to O 2 (catalyzed by transition metal ion, TMI) and H 2 O 2 at pH less than 4.5 (Cheng et al, 2016). Unlike the negative feedback between aerosol loadings and their photochemical production (Makar et al, 2015;Kong et al, 2015), the multiphase reactions induce a positive feedback mechanism, i.e., higher particle matter levels lead to more aerosol water, which accelerates sulfate production and further increases the aerosol concentration (G. J. Zheng et al, 2020;Su et al, 2020;Cheng et al, 2016).…”

mentioning

confidence: 99%

Aerosol pH and chemical regimes of sulfate formation in aerosol water during winter haze in the North China Plain

Wei

Zheng

et al. 2020

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Understanding the mechanism of haze formation is crucial for the development of deliberate pollution control strategies. Multiphase chemical reactions in aerosol water have been suggested as an important source of particulate sulfate during severe haze (Cheng et al., 2016; Wang et al., 2016). While the key role of aerosol water has been commonly accepted, the relative importance of different oxidation pathways in the aqueous phase is still under debate mainly due to questions about aerosol pH. To investigate the spatiotemporal variability of aerosol pH and sulfate formation during winter in the North China Plain (NCP), we have developed a new aerosol water chemistry (AWAC) module for the WRF-Chem model (Weather Research and Forecasting model coupled with Chemistry). Using the WRF-Chem-AWAC model, we performed a comprehensive survey of the atmospheric conditions characteristic for wintertime in the NCP focusing on January 2013. We find that aerosol pH exhibited a strong vertical gradient and distinct diurnal cycle which was closely associated with the spatiotemporal variation in the abundance of acidic and alkaline fine particle components and their gaseous counterparts. Over Beijing, the average aerosol pH at the surface layer was ∼5.4 and remained nearly constant around ∼5 up to ∼2 km above ground level; further aloft, the acidity rapidly increased to pH ∼0 at ∼3 km. The pattern of aerosol acidity increasing with altitude persisted over the NCP, while the specific levels and gradients of pH varied between different regions. In the region north of ∼41∘ N, the mean pH values at the surface level were typically greater than 6, and the main pathway of sulfate formation in aerosol water was S(IV) oxidation by ozone. South of ∼41∘ N, the mean pH values at the surface level were typically in the range of 4.4 to 5.7, and different chemical regimes and reaction pathways of sulfate formation prevailed in four different regions depending on reactant concentrations and atmospheric conditions. The NO2 reaction pathway prevailed in the megacity region of Beijing and the large area of Hebei Province to the south and west of Beijing, as well as part of Shandong Province. The transition metal ion (TMI) pathway dominated in the inland region to the west and the coastal regions to the east of Beijing, and the H2O2 pathway dominated in the region extending further south (Shandong and Henan provinces). In all of these regions, the O3 and TMI pathways in aerosol water, as well as the gas-particle partitioning of H2SO4 vapor, became more important with increasing altitude. Sensitivity tests show that the rapid production of sulfate in the NCP can be maintained over a wide range of aerosol acidity (e.g., pH =4.2–5.7) with transitions from dominant TMI pathway regimes to dominant NO2∕O3 pathway regimes.

show abstract

“…3, respectively). In the CTRL scenario, emissfNH3 has been set to 2, as recent studies using top-down inverse modeling (Van Damme et al, 2018;Wang et al, 2018;Zhang et al, 2018a;Kong et al, 2019) and direct measurement found that previous bottom-up inventories might underestimate the NH3 emissions, and MEIC inventory was estimated to under-predict NH3 emissions by about 40% over the 10 North China Plain (Kong et al, 2019). As shown in Table S7 of Supplement, doubling the NH3 emissions better match the observed ammonia and ammonium at urban Beijing sites during wintertime (Meng et al, 2011;Liu et al, 2017;Song et al, 2018).…”

Section: Wrf-chem Model Configuration and Scenariosmentioning

confidence: 99%

Aerosol pH and chemical regimes of sulfate formation in aerosol water during winter haze in the North China Plain

Tao¹,

Su²,

Zheng³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Understanding the mechanism of haze formation is crucial for the development of deliberate pollution control strategies. Multiphase chemical reactions in aerosol water have been suggested as an important source of particulate sulfate during severe haze (Cheng et al., 2016; Wang et al., 2016). While the key role of aerosol water has been commonly accepted, the relative importance of different oxidation pathways in the aqueous phase is still under debate, mainly due to questions about aerosol pH. To investigate the spatio-temporal variability of aerosol pH and sulfate formation during winter in the North China Plain (NCP), we have developed a new aerosol water chemistry module (AWAC) for the WRF-Chem model (Weather Research and Forecasting model coupled with Chemistry). Using the WRF-Chem-AWAC model, we performed a comprehensive survey of the atmospheric conditions characteristic for wintertime in the NCP, focusing on January 2013. We find that aerosol pH exhibited a strong vertical gradient and distinct diurnal cycle, which was closely associated with the spatio-temporal variation in the relative abundance of acidic and alkaline fine particle components and their gaseous counterparts. Over Beijing, the average aerosol pH at the surface layer was ~ 5.4 and remained nearly constant around ~ 5 up to ~ 2 km above ground level; further aloft, the acidity rapidly increased to pH ~ 0 at ~ 3 km. The pattern of aerosol acidity increase with altitude persisted over the NCP, while the specific levels and gradients of pH varied between different regions. In the region north of ~ 41° N, the mean pH values at surface level were typically > 6 and the main pathway of sulfate formation in aerosol water was S(IV) oxidation by ozone. South of ~ 41° N, the mean pH values at surface level were typically in the range of 4.4 to 5.7, and different chemical regimes and reaction pathways of sulfate formation prevailed in four different regions, depending on reactant concentrations and atmospheric conditions. The NO2 reaction pathway prevailed in the megacity region of Beijing and the large area of Hebei Province to the south and west of Beijing, as well as part of Shandong Province. The transition metal ion (TMI) pathway dominated in the inland region to the west and the coastal regions to the east of Beijing, and the H2O2 pathway dominated in the region extending further south (Shandong and Henan Provinces). In all of these regions, the O3 and TMI pathways in aerosol water as well as the gas-particle partitioning of H2SO4 vapor became more important with increasing altitude. Although pH is sensitive to the abundance of NH3 and crustal particles, we show that the rapid production of sulfate in the NCP can be maintained over a wide range of aerosol acidity (e.g., pH = 4.2–5.7) with transitions from TMI pathway dominated to NO2/O3 pathway dominated regimes.

show abstract

Improved Inversion of Monthly Ammonia Emissions in China Based on the Chinese Ammonia Monitoring Network and Ensemble Kalman Filter

Cited by 94 publications

References 66 publications

Global modeling of heterogeneous hydroxymethanesulfonate chemistry

Global modeling of heterogeneous hydroxymethanesulfonate chemistry

Aerosol pH and chemical regimes of sulfate formation in aerosol water during winter haze in the North China Plain

Aerosol pH and chemical regimes of sulfate formation in aerosol water during winter haze in the North China Plain

Contact Info

Product

Resources

About