Fast sulfate formation from oxidation of SO2 by NO2 and HONO observed in Beijing haze

Wang, Junfeng; Li, Jingyi; Ye, Jianhuai; Zhao, Jian; Wu, Yangzhou; Hu, Jianlin; Liu, Dantong; Nie, Dongyang; Shen, Fuzhen; Huang, Xiaoyong; Huang, Dan Dan; Ji, Dongsheng; Sun, Xingming; Xu, Weiqi; Guo, Jianping; Song, Shaojie; Qin, Yi Ming; Liu, Pengfei; Turner, Jay R.; Lee, Hyun Chul; Hwang, Soon Jung; Liao, Hong; Martin, Scot T.; Zhang, Qi; Chen, Mindong; Sun, Yele; Ge, Xinlei; Jacob, Daniel J.

doi:10.1038/s41467-020-16683-x

Cited by 174 publications

(138 citation statements)

References 59 publications

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…However, we cannot replicate their finding using our observations, which show a positive relationship between NOR and RH across all RH conditions (Figure ). While some studies suggested that the heterogeneous reactions between NO 2 and SO 2 are important during wintertime haze events (e.g., Cheng et al., 2016; J. Wang et al., 2020), analysis of sulfate Δ 17 O observations by Shao et al. (2019) showed that these reactions contribute less than 2% to heterogeneous formation of sulfate based on isotope observations in Beijing during the time period studied here.…”

Section: Discussionmentioning

confidence: 63%

Heterogeneous Nitrate Production Mechanisms in Intense Haze Events in the North China Plain

Chan

Evans

et al. 2021

JGR Atmospheres

View full text Add to dashboard Cite

Studies of wintertime air quality in the North China Plain (NCP) show that particulate‐nitrate pollution persists despite rapid reduction in NOx emissions. This intriguing NOx‐nitrate relationship may originate from non‐linear nitrate‐formation chemistry, but it is unclear which feedback mechanisms dominate in NCP. In this study, we re‐interpret the wintertime observations of 17O excess of nitrate (∆17O(NO3−)) in Beijing using the GEOS‐Chem (GC) chemical transport model to estimate the importance of various nitrate‐production pathways and how their contributions change with the intensity of haze events. We also analyze the relationships between other metrics of NOy chemistry and [PM2.5] in observations and model simulations. We find that the model on average has a negative bias of −0.9‰ and −36% for ∆17O(NO3−) and [Ox,major] (≡ [O3] + [NO2] + [p‐NO3−]), respectively, while overestimating the nitrogen oxidation ratio ([NO3−]/([NO3−] + [NO2])) by +0.12 in intense haze. The discrepancies become larger in more intense haze. We attribute the model biases to an overestimate of NO2‐uptake on aerosols and an underestimate in wintertime O3 concentrations. Our findings highlight a need to address uncertainties related to heterogeneous chemistry of NO2 in air‐quality models. The combined assessment of observations and model results suggest that N2O5 uptake in aerosols and clouds is the dominant nitrate‐production pathway in wintertime Beijing, but its rate is limited by ozone under high‐NOx‐high‐PM2.5 conditions. Nitrate production rates may continue to increase as long as [O3] increases despite reduction in [NOx], creating a negative feedback that reduces the effectiveness of air pollution mitigation.

show abstract

Section: Discussionmentioning

confidence: 63%

Heterogeneous Nitrate Production Mechanisms in Intense Haze Events in the North China Plain

Chan

Evans

et al. 2021

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…Hence, H2O2 appears to be an independent predictor for N2O enhancements in polluted air encountered over the remote oceans. This result raises the question as to whether globally significant production of N2O may be occurring in heterogeneous reactions involving HONO, NO2, or NO redox chemistry nearby to strong sources of reactive pollutants, as has been observed in heavily polluted atmospheres (Wang et al, 2020), or as theorized to occur in the plumes of refineries or power plants (e.g. Pires and Rossi, 1997).…”

Section: Impact Of Emissions On Tropospheric N2o Mixing Ratios Duringmentioning

confidence: 99%

Impact of stratospheric air and surface emissions on tropospheric nitrous oxide during ATom

Ramos¹,

Commane²,

Manninen³

et al. 2021

Preprint

View full text Add to dashboard Cite

Abstract. Nitrous oxide (N2O) is both a greenhouse gas in the troposphere and an ozone depleting substance in the stratosphere and is rapidly increasing in the atmosphere. The spatial distribution of N2O emissions and the sources leading to rising concentrations in the global atmosphere are highly uncertain. We measured the global distribution of tropospheric N2O mixing ratios during the airborne Atmospheric Tomography (ATom) mission. ATom measured mixing ratios of ~300 gas species and aerosol properties in 647 vertical profiles spanning the Pacific, Atlantic, Arctic, and much of the Southern Ocean basins, from nearly Pole to Pole, over four seasons (2016–2018). We measured N2O mixing ratios at 1 Hz using a Quantum Cascade Laser Spectrometer and a new spectral retrieval method to account for the pressure and temperature sensitivity of the instrument when deployed on aircraft. This retrieval strategy improved the precision of our N2O measurements by a factor of 3, enabling us to recover the precision to that of previous missions. Most of the variance of N2O mixing ratios in the troposphere is driven by the influence of N2O-depleted stratospheric air, especially at mid and high latitudes. We observe the downward propagation of lower N2O mixing ratios (compared to surface stations) that tracks the influence of stratosphere-troposphere exchange through the tropospheric column down to the surface, resulting in a seasonal minimum at the surface 2–3 months after the peak stratosphere-to-troposphere exchange in spring. The highest N2O mixing ratios occur close to the equator, extending through the boundary layer and free troposphere. We observed influences from a complex and diverse mixture of N2O sources, with emission source types identified using the rich suite of chemical species measured on ATom and with the geographical origin calculated using an atmospheric transport model. Although ATom flights were mostly over the oceans, the most prominent N2O enhancements were associated with anthropogenic emissions, including industry, oil and gas, urban and biomass burning, especially in the tropical Atlantic outflow from Africa. Enhanced N2O mixing ratios are mostly associated with pollution-related tracers arriving from the coastal area of Nigeria. Peaks of N2O are often well-correlated with indicators of photochemical processing, suggesting possible unexpected source processes. The difficulty of separating the mixture of different sources in the atmosphere contributes to uncertainties in the N2O global budget. The extensive data set from ATom will help improve the understanding of N2O emission processes and their representation in global models.

show abstract

“…1.4, 1.2, 1.1, 5.0, and 1.3, respectively. Positive matrix factorization (PMF) is a receptor model that can identify potential sources without local source profiles provided (Xu et al, 2020). PMF was performed on the high-resolution mass spectra of organics measured by HR-AMS.…”

Section: Ams Data Analysismentioning

confidence: 99%

Persistent primary organic tar particles during the regional wintertime hazes in North China: insights into their aging and optical changes

Liu

Zhang

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. Primary organic aerosol (POA) is a major component of PM2.5 in the winter polluted air in the North China Plain (NCP), but our understanding on the atmospheric aging process of POA particles and the resulting influences on their optical properties is limited. As part of the Atmospheric Pollution and Human Health in a Chinese Megacity (APHH-Beijing) programme, we collected airborne particles at an urban site (Beijing) and an upwind rural site (Gucheng, Hebei province) in the NCP during 13–27 November 2016 for microscopic analyses. We confirmed that a distinct group of spherical or irregular POA particles with high viscosity, defined as primary organic tar (POT) particles, was emitted from the domestic coal and biomass burning at the rural site and was further transported to the urban site during the regional wintertime hazes. During the heavily polluted period (PM2.5 > 200 μg m−3), more than 60 % of the POT particles were thickly coated with secondary inorganic aerosols (named as core–shell POT-SIA particle) through the aging process, suggesting that POT particles can provide surfaces for the heterogeneous reactions of SO2 and NOx. As a result, their average particle-to-core ratios at the rural and urban sites in the heavily polluted period increased to 1.60 and 1.67, respectively. Interestingly, we found that the aging process did not change the morphology and sizes of the POT cores, indicating that POT particles are quite inert in the atmosphere and can be transported long distances. We using the Mie theory estimated that the light absorption of individual POT particles was enhanced by ~ 1.39 times in the heavily polluted period at the rural and urban sites due to the lensing effect of secondary inorganic coatings. We highlight that the lensing effect on POT particles should be considered in radiative forcing models and the governments should continue to promote clean energy in rural areas to effectively reduce primary emissions.

show abstract

Fast sulfate formation from oxidation of SO2 by NO2 and HONO observed in Beijing haze

Cited by 174 publications

References 59 publications

Heterogeneous Nitrate Production Mechanisms in Intense Haze Events in the North China Plain

Heterogeneous Nitrate Production Mechanisms in Intense Haze Events in the North China Plain

Impact of stratospheric air and surface emissions on tropospheric nitrous oxide during ATom

Persistent primary organic tar particles during the regional wintertime hazes in North China: insights into their aging and optical changes

Contact Info

Product

Resources

About