Articles | Volume 22, issue 3
10 Feb 2022
Research article | 10 Feb 2022
High-resolution mapping of regional traffic emissions using land-use machine learning models
Xiaomeng Wu et al.
No articles found.
Rui Li, Meng Peng, Weidong Zhao, Gehui Wang, and Jiming Hao
RF model was used to isolate the effects of emission and meteorology to trace elements in PM2.5 in Tangshan. The result suggested that the control measures facilitated the decreases of Ga, Co, Pb, Zn, and As. It is due to the strict implementation of “coal to gas” strategies and optimization of industrial structure and layout. However, the deweathered levels of Ca, Cr, and Fe only displayed minor decreases, indicating that ferrous metal smelting and vehicle emission controls should be enhanced.
Chao Yan, Yicheng Shen, Dominik Stolzenburg, Lubna Dada, Ximeng Qi, Simo Hakala, Anu-Maija Sundström, Yishuo Guo, Antti Lipponen, Tom V. Kokkonen, Jenni Kontkanen, Runlong Cai, Jing Cai, Tommy Chan, Liangduo Chen, Biwu Chu, Chenjuan Deng, Wei Du, Xiaolong Fan, Xu-Cheng He, Juha Kangasluoma, Joni Kujansuu, Mona Kurppa, Chang Li, Yiran Li, Zhuohui Lin, Yiliang Liu, Yuliang Liu, Yiqun Lu, Wei Nie, Jouni Pulliainen, Xiaohui Qiao, Yonghong Wang, Yifan Wen, Ye Wu, Gan Yang, Lei Yao, Rujing Yin, Gen Zhang, Shaojun Zhang, Feixue Zheng, Ying Zhou, Antti Arola, Johanna Tamminen, Pauli Paasonen, Yele Sun, Lin Wang, Neil M. Donahue, Yongchun Liu, Federico Bianchi, Kaspar R. Daellenbach, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Aijun Ding, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 22, 12207–12220,Short summary
Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles. In urban environments, traffic emissions are a major source of primary pollutants, but their contribution to NPF remains under debate. During the COVID-19 lockdown, traffic emissions were significantly reduced, providing a unique chance to examine their relevance to NPF. Based on our comprehensive measurements, we demonstrate that traffic emissions alone are not able to explain the NPF in Beijing.
Lulu Cui, Di Wu, Shuxiao Wang, Qingcheng Xu, Ruolan Hu, and Jiming Hao
Atmos. Chem. Phys., 22, 11931–11944,Short summary
A 1-year campaign was conducted to characterize VOCs at a Beijing urban site during different episodes. VOCs from fuel evaporation and diesel exhaust, particularly toluene, xylenes, trans-2-butene, acrolein, methyl methacrylate, vinyl acetate, 1-butene, and 1-hexene, were the main contributors. VOCs from diesel exhaust as well as coal and biomass combustion were found to be the dominant contributors for SOAFP, particularly the VOC species toluene, 1-hexene, xylenes, ethylbenzene, and styrene.
Jiandong Wang, Jia Xing, Shuxiao Wang, Rohit Mathur, Jiaping Wang, Yuqiang Zhang, Chao Liu, Jonathan Pleim, Dian Ding, Xing Chang, Jingkun Jiang, Peng Zhao, Shovan Kumar Sahu, Yuzhi Jin, David C. Wong, and Jiming Hao
Atmos. Chem. Phys., 22, 5147–5156,Short summary
Aerosols reduce surface solar radiation and change the photolysis rate and planetary boundary layer stability. In this study, the online coupled meteorological and chemistry model was used to explore the detailed pathway of how aerosol direct effects affect secondary inorganic aerosol. The effects through the dynamics pathway act as an equally or even more important route compared with the photolysis pathway in affecting secondary aerosol concentration in both summer and winter.
Runlong Cai, Chao Yan, Dongsen Yang, Rujing Yin, Yiqun Lu, Chenjuan Deng, Yueyun Fu, Jiaxin Ruan, Xiaoxiao Li, Jenni Kontkanen, Qiang Zhang, Juha Kangasluoma, Yan Ma, Jiming Hao, Douglas R. Worsnop, Federico Bianchi, Pauli Paasonen, Veli-Matti Kerminen, Yongchun Liu, Lin Wang, Jun Zheng, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 21, 2457–2468,Short summary
Based on long-term measurements, we discovered that the collision of H2SO4–amine clusters is the governing mechanism that initializes fast new particle formation in the polluted atmospheric environment of urban Beijing. The mechanism and the governing factors for H2SO4–amine nucleation in the polluted atmosphere are quantitatively investigated in this study.
Jia Xing, Siwei Li, Yueqi Jiang, Shuxiao Wang, Dian Ding, Zhaoxin Dong, Yun Zhu, and Jiming Hao
Atmos. Chem. Phys., 20, 14347–14359,Short summary
Quantifying emission changes is a prerequisite for assessment of control effectiveness in improving air quality. However, traditional bottom-up methods usually take months to perform and limit timely assessments. A novel method was developed by using a response model that provides real-time estimation of emission changes based on air quality observations. It was successfully applied to quantify emission changes on the North China Plain due to the COVID-19 pandemic shutdown.
Jing Cai, Biwu Chu, Lei Yao, Chao Yan, Liine M. Heikkinen, Feixue Zheng, Chang Li, Xiaolong Fan, Shaojun Zhang, Daoyuan Yang, Yonghong Wang, Tom V. Kokkonen, Tommy Chan, Ying Zhou, Lubna Dada, Yongchun Liu, Hong He, Pauli Paasonen, Joni T. Kujansuu, Tuukka Petäjä, Claudia Mohr, Juha Kangasluoma, Federico Bianchi, Yele Sun, Philip L. Croteau, Douglas R. Worsnop, Veli-Matti Kerminen, Wei Du, Markku Kulmala, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 20, 12721–12740,Short summary
By applying both OA PMF and size PMF at the same urban measurement site in Beijing, similar particle source types, including vehicular emissions, cooking emissions and secondary formation-related sources, were resolved by both frameworks and agreed well. It is also found that in the absence of new particle formation, vehicular and cooking emissions dominate the particle number concentration, while secondary particulate matter governed PM2.5 mass during spring and summer in Beijing.
Jia Xing, Dian Ding, Shuxiao Wang, Zhaoxin Dong, James T. Kelly, Carey Jang, Yun Zhu, and Jiming Hao
Atmos. Chem. Phys., 19, 13627–13646,Short summary
The study aims at addressing the challenge in efficient quantification of the nonlinear response of air pollution to precursor emission perturbations. The newly developed observable response indicators can be easily calculated by a combination of ambient concentrations of certain species. Their capability in representing the spatial and temporal variation in PM2.5 and O3 chemistry has also been well evaluated and applied in China.
Xiaoxiao Li, Shaojie Song, Wei Zhou, Jiming Hao, Douglas R. Worsnop, and Jingkun Jiang
Atmos. Chem. Phys., 19, 12163–12174,Short summary
Aerosol liquid water is ubiquitous in ambient aerosol. Using long-term aerosol chemical composition to model the aerosol water in Beijing, we found that water absorbed by organics contributes a significant fraction to the total aerosol water. We emphasize the hygroscopicity of organics is highly variable and should be taken into consideration in modelling. A positive feedback loop between organic hygroscopicity and aerosol water was found as one of the driving factors of severe haze in Beijing.
Daoyuan Yang, Shaojun Zhang, Tianlin Niu, Yunjie Wang, Honglei Xu, K. Max Zhang, and Ye Wu
Atmos. Chem. Phys., 19, 8831–8843,Short summary
Our work developed a high-resolution emission inventory (EMBEV-Link) with extensive traffic data covering the entire city of Beijing, which mapped the heterogeneity of road emissions associated with traffic dynamics. Nonlocal trucks accounted for substantial emissions (e.g., ~ 30 % of NOx), though they are missing in previous inventories. EMBEV-Link can support fine-grained dispersion modeling (e.g., 1 m × 1 m at hotspots) and mitigate the uncertainty in top-down emission mapping.
Xionghui Qiu, Qi Ying, Shuxiao Wang, Lei Duan, Jian Zhao, Jia Xing, Dian Ding, Yele Sun, Baoxian Liu, Aijun Shi, Xiao Yan, Qingcheng Xu, and Jiming Hao
Atmos. Chem. Phys., 19, 6737–6747,Short summary
Current chemical transport models cannot capture the diurnal and nocturnal variation in atmospheric nitrate, which may be relative to the missing atmospheric chlorine chemistry. In this work, the Community Multiscale Air Quality (CMAQ) model with improved chlorine heterogeneous chemistry is applied to simulate the impact of chlorine chemistry on summer nitrate concentrations in Beijing. The results of this work can improve our understanding of nitrate formation.
Haotian Zheng, Siyi Cai, Shuxiao Wang, Bin Zhao, Xing Chang, and Jiming Hao
Atmos. Chem. Phys., 19, 3447–3462,Short summary
The heavy air pollution in the Beijing-Tianjin-Hebei (BTH) region is a global hot topic. We established a unit-based industrial emission inventory for the BTH region. The inventory significantly improved air quality modeling results; this improvement subsequently contributes to an accurate source apportionment of haze pollution and more precisely targeted decision making.
Runlong Cai, Indra Chandra, Dongsen Yang, Lei Yao, Yueyun Fu, Xiaoxiao Li, Yiqun Lu, Lun Luo, Jiming Hao, Yan Ma, Lin Wang, Jun Zheng, Takafumi Seto, and Jingkun Jiang
Atmos. Chem. Phys., 18, 16587–16599,Short summary
Significant influences of transport on measured aerosol size distributions are commonly observed. We propose a method for estimating the contributions of transport to nanoparticles during new particle formation events. This method was used to analyze new particle formation events in Southeast Tibet, Fukue Island, and urban Beijing. The changes in the contributions of transport have a good correlation with the changes in wind speed and direction, indicating the feasibility of the method.
Runlong Cai, Dongsen Yang, Lauri R. Ahonen, Linlin Shi, Frans Korhonen, Yan Ma, Jiming Hao, Tuukka Petäjä, Jun Zheng, Juha Kangasluoma, and Jingkun Jiang
Atmos. Meas. Tech., 11, 4477–4491,Short summary
We tested the performance of four inversion methods to recover sub-3 nm aerosol size distributions using the particle size magnifier (PSM). The PSM is widely used in new particle formation study; however, the inversion methods used in previous studies may report false particle concentrations. Due to the results, we suggest using the expectation–maximization algorithm to address the PSM inversion problem. We also gave practical suggestions on PSM operation based on the inversion analysis.
Yi Tang, Shuxiao Wang, Qingru Wu, Kaiyun Liu, Long Wang, Shu Li, Wei Gao, Lei Zhang, Haotian Zheng, Zhijian Li, and Jiming Hao
Atmos. Chem. Phys., 18, 8279–8291,Short summary
In this study, 3-year measurements of atmospheric Hg were carried out at a rural site in East China. A significant downward trend was observed during the sampling period. This study used a new approach that considers both cluster frequency and the Hg concentration associated with each cluster, and we calculated that atmospheric Hg from the whole region of China has caused a 70 % decline of GEM concentration at the Chongming monitoring site due to strict air pollution control policies in China.
Xing Chang, Shuxiao Wang, Bin Zhao, Siyi Cai, and Jiming Hao
Atmos. Chem. Phys., 18, 4843–4858,Short summary
The Beijing–Tianjin–Hebei region in China has been suffering from a severe particulate matter pollution, and the inter-city transport of the pollutant plays an important role. The current research quantitatively assesses the transport process. We identify three transport pathways. The southwest–northwest one happens in both winter and summer. The transport is stronger at 300–1000 m, or 1–2 days before a pollution peak. The result may guide the joint emission control along the transport pathway.
Qian Yu, Yao Luo, Shuxiao Wang, Zhiqi Wang, Jiming Hao, and Lei Duan
Atmos. Chem. Phys., 18, 495–509,Short summary
This study provides high-quality direct observation data of a clean and a contaminated site in subtropical south China and quantifies the natural forest Hg emission. We find that clean and contaminated forests present a net GEM source with annual average values of 6.67 and 0.30 ng m-2 h-1, respectively; daily variations of GEM fluxes showed a source in the daytime with a peak at 13:00, and as a sink or balance at night; and higher atmospheric GEM concentration restricted the forest GEM emission.
Runlong Cai, Dongsen Yang, Yueyun Fu, Xing Wang, Xiaoxiao Li, Yan Ma, Jiming Hao, Jun Zheng, and Jingkun Jiang
Atmos. Chem. Phys., 17, 12327–12340,Short summary
The governing factors for new particle formation (NPF) events in Beijing were analyzed. The roles of gaseous precursors and aerosol surface area were illustrated. It appears that the abundance of gaseous precursors in Beijing is high enough to have nucleation; however, it is aerosol surface area that determines the occurrence of NPF events in Beijing. Aerosol loading thresholds (in the form of aerosol surface area and PM2.5 concentration) for predicting NPF days in Beijing were suggested.
K. Max Zhang, George Allen, Bo Yang, Geng Chen, Jiajun Gu, James Schwab, Dirk Felton, and Oliver Rattigan
Atmos. Chem. Phys., 17, 11441–11452,Short summary
Woodsmoke is a worldwide public health concern. A reliable marker for woodsmoke will be very useful in air-quality management. DC (Delta-C) has been proposed as a woodsmoke marker in previous studies. However, several researchers raised concerns of whether it is reliable. Our study took advantage of aerosol light absorption and PM2.5 data collected at three US cities/towns dominated by woodsmoke. We showed that DC can be a good qualitative and semi-quantitive marker, but with limitations.
Qingru Wu, Wei Gao, Shuxiao Wang, and Jiming Hao
Atmos. Chem. Phys., 17, 10423–10433,Short summary
Iron and steel production (ISP) is one of the most significant atmospheric Hg emission sources in China. Atmospheric Hg emissions from ISP increased from 11.5 t in 2000 to 32.75 t in 2015 with a peak of 35.65 t in 2013. In the coming years, emissions from ISP are expected to decrease. Although sinter/pellet plants and blast furnaces were the largest two emission processes, emissions from roasting plants and coke ovens accounted for 22 %–34 % of ISP’s emissions.
Jia Xing, Jiandong Wang, Rohit Mathur, Shuxiao Wang, Golam Sarwar, Jonathan Pleim, Christian Hogrefe, Yuqiang Zhang, Jingkun Jiang, David C. Wong, and Jiming Hao
Atmos. Chem. Phys., 17, 9869–9883,Short summary
The assessment of the impacts of aerosol direct effects (ADE) is important for understanding emission reduction strategies that seek co-benefits associated with reductions in both particulate matter and ozone. This study quantifies the ADE impacts on tropospheric ozone by using a two-way coupled meteorology and atmospheric chemistry model. Results suggest that reducing ADE may have the potential risk of increasing ozone in winter, but it will benefit the reduction of maxima ozone in summer.
Biwu Chu, Xiao Zhang, Yongchun Liu, Hong He, Yele Sun, Jingkun Jiang, Junhua Li, and Jiming Hao
Atmos. Chem. Phys., 16, 14219–14230,Short summary
The interactive effects between inorganic and organic species under highly complex pollution conditions remain uncertain and were studied in a smog chamber. This study indicated that the synergistic formation of secondary inorganic and organic aerosol might increase the secondary aerosol load in the atmosphere and contribute haze pollution in eastern China. These synergistic effects were related to the heterogeneous process on aerosol surface and need to be considered in air quality models.
Shaojun Zhang, Ye Wu, Ruikun Huang, Jiandong Wang, Han Yan, Yali Zheng, and Jiming Hao
Atmos. Chem. Phys., 16, 9965–9981,Short summary
For highly populated cities in eastern Asian, traffic management has played an increasingly important role in mitigating local emissions from vehicles. Therefore, high-resolution vehicle emission inventory is an irreplaceable assessment tool. This study selected Macau, the most populated city in the world, to demonstrate a high-resolution simulation of vehicular pollution by coupling detailed local data collected and interdisciplinary models.
Lei Zhang, Shuxiao Wang, Qingru Wu, Fengyang Wang, Che-Jen Lin, Leiming Zhang, Mulin Hui, Mei Yang, Haitao Su, and Jiming Hao
Atmos. Chem. Phys., 16, 2417–2433,
A. Stohl, B. Aamaas, M. Amann, L. H. Baker, N. Bellouin, T. K. Berntsen, O. Boucher, R. Cherian, W. Collins, N. Daskalakis, M. Dusinska, S. Eckhardt, J. S. Fuglestvedt, M. Harju, C. Heyes, Ø. Hodnebrog, J. Hao, U. Im, M. Kanakidou, Z. Klimont, K. Kupiainen, K. S. Law, M. T. Lund, R. Maas, C. R. MacIntosh, G. Myhre, S. Myriokefalitakis, D. Olivié, J. Quaas, B. Quennehen, J.-C. Raut, S. T. Rumbold, B. H. Samset, M. Schulz, Ø. Seland, K. P. Shine, R. B. Skeie, S. Wang, K. E. Yttri, and T. Zhu
Atmos. Chem. Phys., 15, 10529–10566,Short summary
This paper presents a summary of the findings of the ECLIPSE EU project. The project has investigated the climate and air quality impacts of short-lived climate pollutants (especially methane, ozone, aerosols) and has designed a global mitigation strategy that maximizes co-benefits between air quality and climate policy. Transient climate model simulations allowed quantifying the impacts on temperature (e.g., reduction in global warming by 0.22K for the decade 2041-2050) and precipitation.
H. Z. Tian, C. Y. Zhu, J. J. Gao, K. Cheng, J. M. Hao, K. Wang, S. B. Hua, Y. Wang, and J. R. Zhou
Atmos. Chem. Phys., 15, 10127–10147,Short summary
For the first time, with S-shaped curves, the best available representation of time-varying emission factors of 12 heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) from primary anthropogenic sources of China are determined on account of economic transitions and pollution control technology improvement. The temporal and spatial variation characteristics of these heavy metals emissions during the period of 1949−2012 are calculated and evaluated with uncertainty analysis.
X. Fu, S. X. Wang, L. M. Ran, J. E. Pleim, E. Cooter, J. O. Bash, V. Benson, and J. M. Hao
Atmos. Chem. Phys., 15, 6637–6649,Short summary
In this study, we estimate, for the first time, the NH3 emission from the agricultural fertilizer application in China online using the bi-directional CMAQ model coupled to an agro-ecosystem model. Compared with previous researches, this method considers more influencing factors, such as meteorological fields, soil and the fertilizer application, and provides improved NH3 emission with higher spatial and temporal resolution.
B. Zhao, S. X. Wang, J. Xing, K. Fu, J. S. Fu, C. Jang, Y. Zhu, X. Y. Dong, Y. Gao, W. J. Wu, J. D. Wang, and J. M. Hao
Geosci. Model Dev., 8, 115–128,
S. X. Wang, B. Zhao, S. Y. Cai, Z. Klimont, C. P. Nielsen, T. Morikawa, J. H. Woo, Y. Kim, X. Fu, J. Y. Xu, J. M. Hao, and K. B. He
Atmos. Chem. Phys., 14, 6571–6603,
Z. Cheng, S. Wang, X. Fu, J. G. Watson, J. Jiang, Q. Fu, C. Chen, B. Xu, J. Yu, J. C. Chow, and J. Hao
Atmos. Chem. Phys., 14, 4573–4585,
X. Fu, S. X. Wang, Z. Cheng, J. Xing, B. Zhao, J. D. Wang, and J. M. Hao
Atmos. Chem. Phys., 14, 1239–1254,
L. Zhang, S. X. Wang, L. Wang, and J. M. Hao
Atmos. Chem. Phys., 13, 10505–10516,
B. Zhao, S. X. Wang, H. Liu, J. Y. Xu, K. Fu, Z. Klimont, J. M. Hao, K. B. He, J. Cofala, and M. Amann
Atmos. Chem. Phys., 13, 9869–9897,
Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)Methane emissions from China: a high-resolution inversion of TROPOMI satellite observationsEstimated regional CO2 flux and uncertainty based on an ensemble of atmospheric CO2 inversionsAssessing the representativity of NH3 measurements influenced by boundary-layer dynamics and the turbulent dispersion of a nearby emission sourceTowards monitoring CO2 source-sink distribution over India via inverse modelling: Quantifying the fine-scale spatiotemporal variability of atmospheric CO2 mole fractionAnalysis of CO2, CH4, and CO surface and column concentrations observed at Réunion Island by assessing WRF-Chem simulationsTechnical note: Interpretation of field observations of point-source methane plume using observation-driven large-eddy simulationsQuantifying fossil fuel methane emissions using observations of atmospheric ethane and an uncertain emission ratioThe impact of peripheral circulation characteristics of typhoon on sustained ozone episodes over the Pearl River Delta region, ChinaUpdated Global Fuel Exploitation Inventory (GFEI) for methane emissions from the oil, gas, and coal sectors: evaluation with inversions of atmospheric methane observationsLand use and anthropogenic heat modulate ozone by meteorology: a perspective from the Yangtze River Delta regionFour years of global carbon cycle observed from the Orbiting Carbon Observatory 2 (OCO-2) version 9 and in situ data and comparison to OCO-2 version 7Data assimilation of CrIS NH3 satellite observations for improving spatiotemporal NH3 distributions in LOTOS-EUROSOn the cross-tropopause transport of water by tropical convective overshoots: a mesoscale modelling study constrained by in situ observations during the TRO-Pico field campaign in BrazilEffects of ozone–vegetation interactions on meteorology and air quality in China using a two-way coupled land–atmosphere modelThe drivers and health risks of unexpected surface ozone enhancements over the Sichuan Basin, China, in 2020Estimating 2010–2015 anthropogenic and natural methane emissions in Canada using ECCC surface and GOSAT satellite observationsTechnical note: AQMEII4 Activity 1: evaluation of wet and dry deposition schemes as an integral part of regional-scale air quality modelsEvaluating the impact of storage-and-release on aircraft-based mass-balance methodology using a regional air-quality modelThe regional impact of urban emissions on air quality in Europe: the role of the urban canopy effectsA new inverse modeling approach for emission sources based on the DDM-3D and 3DVAR techniques: an application to air quality forecasts in the Beijing–Tianjin–Hebei regionAssessing urban methane emissions using column-observing portable Fourier transform infrared (FTIR) spectrometers and a novel Bayesian inversion frameworkEvidence of a recent decline in UK emissions of hydrofluorocarbons determined by the InTEM inverse model and atmospheric measurementsVehicle-induced turbulence and atmospheric pollutionA comparative study to reveal the influence of typhoons on the transport, production and accumulation of O3 in the Pearl River Delta, ChinaSensitivity to the sources of uncertainties in the modeling of atmospheric CO2 concentration within and in the vicinity of ParisEstimating Upper Silesian coal mine methane emissions from airborne in situ observations and dispersion modelingAnalysis of CO2 spatio-temporal variations in China using a weather–biosphere online coupled modelMobile monitoring of urban air quality at high spatial resolution by low-cost sensors: impacts of COVID-19 pandemic lockdownLinking global terrestrial CO2 fluxes and environmental drivers: inferences from the Orbiting Carbon Observatory 2 satellite and terrestrial biospheric modelsUncertainties in the Emissions Database for Global Atmospheric Research (EDGAR) emission inventory of greenhouse gasesUsing TROPOspheric Monitoring Instrument (TROPOMI) measurements and Weather Research and Forecasting (WRF) CO modelling to understand the contribution of meteorology and emissions to an extreme air pollution event in IndiaGlobal methane budget and trend, 2010–2017: complementarity of inverse analyses using in situ (GLOBALVIEWplus CH4 ObsPack) and satellite (GOSAT) observationsCOVID-19 lockdowns highlight a risk of increasing ozone pollution in European urban areasLarge-eddy simulation of traffic-related air pollution at a very high resolution in a mega-city: evaluation against mobile sensors and insights for influencing factorsTechnical note: Emission mapping of key sectors in Ho Chi Minh City, Vietnam, using satellite-derived urban land use dataImpact of western Pacific subtropical high on ozone pollution over eastern ChinaHigh-resolution hybrid inversion of IASI ammonia columns to constrain US ammonia emissions using the CMAQ adjoint modelSimulation of radon-222 with the GEOS-Chem global model: emissions, seasonality, and convective transportRegional CO2 fluxes from 2010 to 2015 inferred from GOSAT XCO2 retrievals using a new version of the Global Carbon Assimilation SystemThe friagem event in the central Amazon and its influence on micrometeorological variables and atmospheric chemistryModeling atmospheric ammonia using agricultural emissions with improved spatial variability and temporal dynamicsQuantifying methane emissions from Queensland's coal seam gas producing Surat Basin using inventory data and a regional Bayesian inversionErrors in top-down estimates of emissions using a known sourceThe impact of urban land-surface on extreme air pollution over central EuropeImpacts of future land use and land cover change on mid-21st-century surface ozone air quality: distinguishing between the biogeophysical and biogeochemical effectsWhat have we missed when studying the impact of aerosols on surface ozone via changing photolysis rates?Stratospheric impact on the Northern Hemisphere winter and spring ozone interannual variability in the troposphereDesign and evaluation of CO2 observation network to optimize surface CO2 fluxes in Asia using observation system simulation experimentsOzone pollution over China and India: seasonality and sourcesInfluences of oceanic ozone deposition on tropospheric photochemistry
Zichong Chen, Daniel J. Jacob, Hannah Nesser, Melissa P. Sulprizio, Alba Lorente, Daniel J. Varon, Xiao Lu, Lu Shen, Zhen Qu, Elise Penn, and Xueying Yu
Atmos. Chem. Phys., 22, 10809–10826,Short summary
We quantify methane emissions in China and contributions from different sectors by inverse analysis of 2019 TROPOMI satellite observations of atmospheric methane. We find that anthropogenic methane emissions for China are underestimated in the national inventory. Our estimate of emissions indicates a small life-cycle loss rate, implying net climate benefits from the current
coal-to-gasenergy transition in China. However, this small loss rate can be misleading given China's high gas imports.
Naveen Chandra, Prabir K. Patra, Yousuke Niwa, Akihiko Ito, Yosuke Iida, Daisuke Goto, Shinji Morimoto, Masayuki Kondo, Masayuki Takigawa, Tomohiro Hajima, and Michio Watanabe
Atmos. Chem. Phys., 22, 9215–9243,Short summary
This paper is intended to accomplish two goals: (1) quantify mean and uncertainty in non-fossil-fuel CO2 fluxes estimated by inverse modeling and (2) provide in-depth analyses of regional CO2 fluxes in support of emission mitigation policymaking. CO2 flux variability and trends are discussed concerning natural climate variability and human disturbances using multiple lines of evidence.
Ruben B. Schulte, Margreet C. van Zanten, Bart J. H. van Stratum, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 22, 8241–8257,Short summary
We present a fine-scale simulation framework, utilizing large-eddy simulations, to assess NH3 measurements influenced by boundary-layer dynamics and turbulent dispersion of a nearby emission source. The minimum required distance from an emission source differs for concentration and flux measurements, from 0.5–3.0 km and 0.75–4.5 km, respectively. The simulation framework presented here proves to be a powerful and versatile tool for future NH3 research at high spatio-temporal resolutions.
Vishnu Thilakan, Dhanyalekshmi Pillai, Christoph Gerbig, Michal Galkowski, Aparnna Ravi, and Thara Anna Mathew
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
This paper demonstrates how we can use atmospheric observations to improve the CO2 flux estimates of India. This is achieved by improving the representation of terrain, mesoscale transport and flux variations. We quantify the impact of unresolved variations in the current models on optimally estimated fluxes via inverse modelling and quantify the associated flux uncertainty. We illustrate how a parameterization scheme captures this variability in the coarse models.
Sieglinde Callewaert, Jérôme Brioude, Bavo Langerock, Valentin Duflot, Dominique Fonteyn, Jean-François Müller, Jean-Marc Metzger, Christian Hermans, Nicolas Kumps, Michel Ramonet, Morgan Lopez, Emmanuel Mahieu, and Martine De Mazière
Atmos. Chem. Phys., 22, 7763–7792,Short summary
A regional atmospheric transport model is used to analyze the factors contributing to CO2, CH4, and CO observations at Réunion Island. We show that the surface observations are dominated by local fluxes and dynamical processes, while the column data are influenced by larger-scale mechanisms such as biomass burning plumes. The model is able to capture the measured time series well; however, the results are highly dependent on accurate boundary conditions and high-resolution emission inventories.
Anja Ražnjević, Chiel van Heerwaarden, Bart van Stratum, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, and Maarten Krol
Atmos. Chem. Phys., 22, 6489–6505,Short summary
Mobile measurement techniques (e.g., instruments placed in cars) are often employed to identify and quantify individual sources of greenhouse gases. Due to road restrictions, those observations are often sparse (temporally and spatially). We performed high-resolution simulations of plume dispersion, with realistic weather conditions encountered in the field, to reproduce the measurement process of a methane plume emitted from an oil well and provide additional information about the plume.
Alice E. Ramsden, Anita L. Ganesan, Luke M. Western, Matthew Rigby, Alistair J. Manning, Amy Foulds, James L. France, Patrick Barker, Peter Levy, Daniel Say, Adam Wisher, Tim Arnold, Chris Rennick, Kieran M. Stanley, Dickon Young, and Simon O'Doherty
Atmos. Chem. Phys., 22, 3911–3929,Short summary
Quantifying methane emissions from different sources is a key focus of current research. We present a method for estimating sectoral methane emissions that uses ethane as a tracer for fossil fuel methane. By incorporating variable ethane : methane emission ratios into this model, we produce emissions estimates with improved uncertainty characterisation. This method will be particularly useful for studying methane emissions in areas with complex distributions of sources.
Ying Li, Xiangjun Zhao, Xuejiao Deng, and Jinhui Gao
Atmos. Chem. Phys., 22, 3861–3873,Short summary
This study finds a new phenomenon of weak wind deepening (WWD) associated with the peripheral circulation of typhoon and gives the influence mechanism of WWD on its contribution to daily variation during sustained ozone episodes. The WWD provides the premise for pollution accumulation in the whole PBL and continued enhancement of ground-level ozone via vertical mixing processes. These findings could benefit the daily daytime ozone forecast in the PRD region and other areas.
Tia R. Scarpelli, Daniel J. Jacob, Shayna Grossman, Xiao Lu, Zhen Qu, Melissa P. Sulprizio, Yuzhong Zhang, Frances Reuland, Deborah Gordon, and John R. Worden
Atmos. Chem. Phys., 22, 3235–3249,Short summary
We present a spatially explicit version of the national inventories of oil, gas, and coal methane emissions as submitted by individual countries to the United Nations Framework Convention on Climate Change (UNFCCC) in 2021. We then use atmospheric modeling to compare our inventory emissions to atmospheric methane observations with the goal of identifying potential under- and overestimates of oil–gas methane emissions in the national inventories.
Chenchao Zhan and Min Xie
Atmos. Chem. Phys., 22, 1351–1371,Short summary
The changes of land use and anthropogenic heat (AH) derived from urbanization can affect meteorology and in turn O3 evolution. In this study, we briefly describe the general features of O3 pollution in the Yangtze River Delta (YRD) based on in situ observational data. Then, the impacts of land use and anthropogenic heat on O3 via changing the meteorological factors and local circulations are investigated in this region using the WRF-Chem model.
Hélène Peiro, Sean Crowell, Andrew Schuh, David F. Baker, Chris O'Dell, Andrew R. Jacobson, Frédéric Chevallier, Junjie Liu, Annmarie Eldering, David Crisp, Feng Deng, Brad Weir, Sourish Basu, Matthew S. Johnson, Sajeev Philip, and Ian Baker
Atmos. Chem. Phys., 22, 1097–1130,Short summary
Satellite CO2 observations are constantly improved. We study an ensemble of different atmospheric models (inversions) from 2015 to 2018 using separate ground-based data or two versions of the OCO-2 satellite. Our study aims to determine if different satellite data corrections can yield different estimates of carbon cycle flux. A difference in the carbon budget between the two versions is found over tropical Africa, which seems to show the impact of corrections applied in satellite data.
Shelley van der Graaf, Enrico Dammers, Arjo Segers, Richard Kranenburg, Martijn Schaap, Mark W. Shephard, and Jan Willem Erisman
Atmos. Chem. Phys., 22, 951–972,Short summary
CrIS NH3 satellite observations are assimilated into the LOTOS-EUROS model using two different methods. In the first method the data are used to fit spatially varying NH3 emission time factors. In the second method a local ensemble transform Kalman filter is used. Compared to in situ observations, combining both methods led to the most significant improvements in the modeled concentrations and deposition, illustrating the usefulness of CrIS NH3 to improve the spatiotemporal distribution of NH3.
Abhinna K. Behera, Emmanuel D. Rivière, Sergey M. Khaykin, Virginie Marécal, Mélanie Ghysels, Jérémie Burgalat, and Gerhard Held
Atmos. Chem. Phys., 22, 881–901,Short summary
Deep convection overshooting the stratosphere's contribution to the global stratospheric water budget is still being quantified. We ran three different cloud-resolving simulations of an observed case of overshoots in Bauru during the TRO-Pico balloon campaign in the context of upscaling the impact of overshoots at a large scale. These simulations, which have been validated with balloon-borne and S-band radar measurements, shed light on the local-scale variability and composition of overshoots.
Jiachen Zhu, Amos P. K. Tai, and Steve Hung Lam Yim
Atmos. Chem. Phys., 22, 765–782,Short summary
This study assessed O3 damage to plant and the subsequent effects on meteorology and air quality in China, whereby O3, meteorology, and vegetation can co-evolve with each other. We provided comprehensive understanding about how O3–vegetation impacts adversely affect plant growth and crop production, and contribute to global warming and severe O3 air pollution in China. Our findings clearly pinpoint the need to consider the O3 damage effects in both air quality studies and climate change studies.
Youwen Sun, Hao Yin, Xiao Lu, Justus Notholt, Mathias Palm, Cheng Liu, Yuan Tian, and Bo Zheng
Atmos. Chem. Phys., 21, 18589–18608,Short summary
This study uses high-resolution nested-grid GEOS-Chem simulation, the eXtreme Gradient Boosting (XGBoost) machine learning method, and the exposure–response relationship to determine the drivers and evaluate the health risks of the unexpected surface O3 enhancements over the Sichuan Basin in 2020. These unexpected O3 enhancements were induced by meteorological anomalies and caused dramatically high health risks.
Sabour Baray, Daniel J. Jacob, Joannes D. Maasakkers, Jian-Xiong Sheng, Melissa P. Sulprizio, Dylan B. A. Jones, A. Anthony Bloom, and Robert McLaren
Atmos. Chem. Phys., 21, 18101–18121,Short summary
We use 2010–2015 surface and satellite observations to disentangle methane from anthropogenic and natural sources in Canada. Using a chemical transport model (GEOS-Chem), the mismatch between modelled and observed methane concentrations can be used to infer emissions according to Bayesian statistics. Compared to prior knowledge, we show higher anthropogenic emissions attributed to energy and/or agriculture in Western Canada and lower natural emissions from Boreal wetlands.
Stefano Galmarini, Paul Makar, Olivia E. Clifton, Christian Hogrefe, Jesse O. Bash, Roberto Bellasio, Roberto Bianconi, Johannes Bieser, Tim Butler, Jason Ducker, Johannes Flemming, Alma Hodzic, Christopher D. Holmes, Ioannis Kioutsioukis, Richard Kranenburg, Aurelia Lupascu, Juan Luis Perez-Camanyo, Jonathan Pleim, Young-Hee Ryu, Roberto San Jose, Donna Schwede, Sam Silva, and Ralf Wolke
Atmos. Chem. Phys., 21, 15663–15697,Short summary
This technical note presents the research protocols for phase 4 of the Air Quality Model Evaluation International Initiative (AQMEII4). This initiative has three goals: (i) to define the state of wet and dry deposition in regional models, (ii) to evaluate how dry deposition influences air concentration and flux predictions, and (iii) to identify the causes for prediction differences. The evaluation compares LULC-specific dry deposition and effective conductances and fluxes.
Sepehr Fathi, Mark Gordon, Paul A. Makar, Ayodeji Akingunola, Andrea Darlington, John Liggio, Katherine Hayden, and Shao-Meng Li
Atmos. Chem. Phys., 21, 15461–15491,Short summary
We have investigated the accuracy of aircraft-based mass balance methodologies through computer model simulations of the atmosphere and air quality at a regional high-resolution scale. We have defined new quantitative metrics to reduce emission retrieval uncertainty by evaluating top-down mass balance estimates against the known simulated meteorology and input emissions. We also recommend methodologies and flight strategies for improved retrievals in future aircraft-based studies.
Peter Huszar, Jan Karlický, Jana Marková, Tereza Nováková, Marina Liaskoni, and Lukáš Bartík
Atmos. Chem. Phys., 21, 14309–14332,Short summary
Urban areas are strong hot spots of emissions influencing local and regional air quality. Cities furthermore influence the meteorological conditions due to their characteristic surface properties and geometry. We found that if these latter effects are not included in the quantification of the impact of urban emissions on regional air quality, this impact will be overestimated, and this overestimation is mainly due to the enhanced turbulence that is present in cities compared to rural areas.
Xinghong Cheng, Zilong Hao, Zengliang Zang, Zhiquan Liu, Xiangde Xu, Shuisheng Wang, Yuelin Liu, Yiwen Hu, and Xiaodan Ma
Atmos. Chem. Phys., 21, 13747–13761,Short summary
We develop a new inversion method of emission sources based on sensitivity analysis and the three-dimension variational technique. The novel explicit observation operator matrix between emission sources and the receptor’s concentrations is established. Then this method is applied to a typical heavy haze episode in North China, and spatiotemporal variations of SO2, NO2, and O3 concentrations simulated using a posterior emission sources are compared with results using an a priori inventory.
Taylor S. Jones, Jonathan E. Franklin, Jia Chen, Florian Dietrich, Kristian D. Hajny, Johannes C. Paetzold, Adrian Wenzel, Conor Gately, Elaine Gottlieb, Harrison Parker, Manvendra Dubey, Frank Hase, Paul B. Shepson, Levi H. Mielke, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 13131–13147,Short summary
Methane emissions from leaks in natural gas pipes are often a large source in urban areas, but they are difficult to measure on a city-wide scale. Here we use an array of innovative methane sensors distributed around the city of Indianapolis and a new method of combining their data with an atmospheric model to accurately determine the magnitude of these emissions, which are about 70 % larger than predicted. This method can serve as a framework for cities trying to account for their emissions.
Alistair J. Manning, Alison L. Redington, Daniel Say, Simon O'Doherty, Dickon Young, Peter G. Simmonds, Martin K. Vollmer, Jens Mühle, Jgor Arduini, Gerard Spain, Adam Wisher, Michela Maione, Tanja J. Schuck, Kieran Stanley, Stefan Reimann, Andreas Engel, Paul B. Krummel, Paul J. Fraser, Christina M. Harth, Peter K. Salameh, Ray F. Weiss, Ray Gluckman, Peter N. Brown, John D. Watterson, and Tim Arnold
Atmos. Chem. Phys., 21, 12739–12755,Short summary
This paper estimates UK emissions of important greenhouse gases (hydrofluorocarbons (HFCs)) using high-quality atmospheric observations and atmospheric modelling. We compare these estimates with those submitted by the UK to the United Nations. We conclude that global concentrations of these gases are still increasing. Our estimates for the UK are 73 % of those reported and that the UK emissions are now falling, demonstrating an impact of UK government policy.
Paul A. Makar, Craig Stroud, Ayodeji Akingunola, Junhua Zhang, Shuzhan Ren, Philip Cheung, and Qiong Zheng
Atmos. Chem. Phys., 21, 12291–12316,Short summary
Vehicle pollutant emissions occur in an environment where upward transport can be enhanced due to the turbulence created by the vehicles as they move through the atmosphere. An approach for including these turbulence effects in regional air pollution forecast models has been derived from theoretical, observation, and higher-resolution modeling. The enhanced mixing, which occurs in the immediate vicinity of roadways, changes pollutant concentrations on the regional to continental scale.
Kun Qu, Xuesong Wang, Yu Yan, Jin Shen, Teng Xiao, Huabin Dong, Limin Zeng, and Yuanhang Zhang
Atmos. Chem. Phys., 21, 11593–11612,Short summary
Typhoons above the Northwest Pacific frequently lead to severe ambient ozone pollution in the Pearl River Delta, China, in autumn and summer. However, typhoons do not enhance ozone transport, production and accumulation at the same time, and differences also exist between these influences in two seasons. Through systematic comparisons, we revealed the complex interactions between local meteorology and ozone processes, which is essential for understanding the causes of regional ozone pollution.
Jinghui Lian, François-Marie Bréon, Grégoire Broquet, Thomas Lauvaux, Bo Zheng, Michel Ramonet, Irène Xueref-Remy, Simone Kotthaus, Martial Haeffelin, and Philippe Ciais
Atmos. Chem. Phys., 21, 10707–10726,Short summary
Currently there is growing interest in monitoring city-scale CO2 emissions based on atmospheric CO2 measurements, atmospheric transport modeling, and inversion technique. We analyze the various sources of uncertainty that impact the atmospheric CO2 modeling and that may compromise the potential of this method for the monitoring of CO2 emission over Paris. Results suggest selection criteria for the assimilation of CO2 measurements into the inversion system that aims at retrieving city emissions.
Julian Kostinek, Anke Roiger, Maximilian Eckl, Alina Fiehn, Andreas Luther, Norman Wildmann, Theresa Klausner, Andreas Fix, Christoph Knote, Andreas Stohl, and André Butz
Atmos. Chem. Phys., 21, 8791–8807,Short summary
Abundant mining and industrial activities in the Upper Silesian Coal Basin lead to large emissions of the potent greenhouse gas methane. This study quantifies these emissions with continuous, high-precision airborne measurements and dispersion modeling. Our emission estimates are in line with values reported in the European Pollutant Release and Transfer Register (E-PRTR 2017) but significantly lower than values reported in the Emissions Database for Global Atmospheric Research (EDGAR v4.3.2).
Xinyi Dong, Man Yue, Yujun Jiang, Xiao-Ming Hu, Qianli Ma, Jingjiao Pu, and Guangqiang Zhou
Atmos. Chem. Phys., 21, 7217–7233,Short summary
The dynamics of CO2 has received considerable attention in the literature, yet uncertainties remain. We applied an online coupled weather-biosphere model to simulate biosphere processes and meteorology simultaneously to characterize CO2 dynamics in China. Anthropogenic emission was more influential in upper air, and the biosphere flux played a more important role in surface CO2, suggesting a significant influence of the boundary layer thermal structure on the accumulation and depletion of CO2.
Shibao Wang, Yun Ma, Zhongrui Wang, Lei Wang, Xuguang Chi, Aijun Ding, Mingzhi Yao, Yunpeng Li, Qilin Li, Mengxian Wu, Ling Zhang, Yongle Xiao, and Yanxu Zhang
Atmos. Chem. Phys., 21, 7199–7215,Short summary
Mobile monitoring with low-cost sensors is a promising approach to garner high-spatial-resolution observations representative of the community scale. We develop a grid analysis method to obtain 50 m resolution maps of major air pollutants (CO, NO2, and O3) based on GIS technology. Our results demonstrate the sensing power of mobile monitoring for urban air pollution, which provides detailed information for source attribution and accurate traceability at the urban micro-scale.
Zichong Chen, Junjie Liu, Daven K. Henze, Deborah N. Huntzinger, Kelley C. Wells, Stephen Sitch, Pierre Friedlingstein, Emilie Joetzjer, Vladislav Bastrikov, Daniel S. Goll, Vanessa Haverd, Atul K. Jain, Etsushi Kato, Sebastian Lienert, Danica L. Lombardozzi, Patrick C. McGuire, Joe R. Melton, Julia E. M. S. Nabel, Benjamin Poulter, Hanqin Tian, Andrew J. Wiltshire, Sönke Zaehle, and Scot M. Miller
Atmos. Chem. Phys., 21, 6663–6680,Short summary
NASA's Orbiting Carbon Observatory 2 (OCO-2) satellite observes atmospheric CO2 globally. We use a multiple regression and inverse model to quantify the relationships between OCO-2 and environmental drivers within individual years for 2015–2018 and within seven global biomes. Our results point to limitations of current space-based observations for inferring environmental relationships but also indicate the potential to inform key relationships that are very uncertain in process-based models.
Efisio Solazzo, Monica Crippa, Diego Guizzardi, Marilena Muntean, Margarita Choulga, and Greet Janssens-Maenhout
Atmos. Chem. Phys., 21, 5655–5683,Short summary
We conducted an extensive analysis of the structural uncertainty of the Emissions Database for Global Atmospheric Research (EDGAR) emission inventory of greenhouse gases, which adds a much needed reliability dimension to the accuracy of the emission estimates. The study undertakes in-depth analyses of the implication of aggregating emissions from different sources and/or countries on the accuracy. Results are presented for all emissions sectors according to IPCC definitions.
Ashique Vellalassery, Dhanyalekshmi Pillai, Julia Marshall, Christoph Gerbig, Michael Buchwitz, Oliver Schneising, and Aparnna Ravi
Atmos. Chem. Phys., 21, 5393–5414,Short summary
We investigate factors contributing to the severe and persistent air quality degradation in northern India that has worsened during every winter over the last decade. This is achieved by implementing atmospheric modelling and using recently available Sentinel-5 P satellite data for carbon monoxide. We see a minimal role of biomass burning, except for the state of Punjab. The aim is to focus on residential and industrial emission reduction strategies to tackle air pollution over northern India.
Xiao Lu, Daniel J. Jacob, Yuzhong Zhang, Joannes D. Maasakkers, Melissa P. Sulprizio, Lu Shen, Zhen Qu, Tia R. Scarpelli, Hannah Nesser, Robert M. Yantosca, Jianxiong Sheng, Arlyn Andrews, Robert J. Parker, Hartmut Boesch, A. Anthony Bloom, and Shuang Ma
Atmos. Chem. Phys., 21, 4637–4657,Short summary
We use an analytical solution to the Bayesian inverse problem to quantitatively compare and combine the information from satellite and in situ observations, and to estimate global methane budget and their trends over the 2010–2017 period. We find that satellite and in situ observations are to a large extent complementary in the inversion for estimating global methane budget, and reveal consistent corrections of regional anthropogenic and wetland methane emissions relative to the prior inventory.
Stuart K. Grange, James D. Lee, Will S. Drysdale, Alastair C. Lewis, Christoph Hueglin, Lukas Emmenegger, and David C. Carslaw
Atmos. Chem. Phys., 21, 4169–4185,Short summary
The changes in mobility across Europe due to the COVID-19 lockdowns had consequences for air quality. We compare what was experienced to estimates of "what would have been" without the lockdowns. Nitrogen dioxide (NO2), an important vehicle-sourced pollutant, decreased by a third. However, ozone (O3) increased in response to lower NO2. Because NO2 is decreasing over time, increases in O3 can be expected in European urban areas and will require management to avoid future negative outcomes.
Yanxu Zhang, Xingpei Ye, Shibao Wang, Xiaojing He, Lingyao Dong, Ning Zhang, Haikun Wang, Zhongrui Wang, Yun Ma, Lei Wang, Xuguang Chi, Aijun Ding, Mingzhi Yao, Yunpeng Li, Qilin Li, Ling Zhang, and Yongle Xiao
Atmos. Chem. Phys., 21, 2917–2929,Short summary
Urban air quality varies drastically at street scale, but traditional methods are too coarse to resolve it. We develop a 10 m resolution air quality model and apply it for traffic-related carbon monoxide air quality in Nanjing megacity. The model reveals a detailed geographical dispersion pattern of air pollution in and out of the road network and agrees well with a validation dataset. The model can be a vigorous part of the smart city system and inform urban planning and air quality management.
Trang Thi Quynh Nguyen, Wataru Takeuchi, Prakhar Misra, and Sachiko Hayashida
Atmos. Chem. Phys., 21, 2795–2818,Short summary
This study provides annual emissions of transportation, manufacturing industries and construction, and residential areas at 1 km resolution from 2009 to 2016 for Ho Chi Minh City, Vietnam. Our originality is our use of satellite-derived urban land use morphological maps. These maps which are based on building height provided by a coarse-resolution satellite-derived digital surface model (DSM) and urban built-up area classified from Landsat images allow spatial disaggregation of annual emissions.
Zhongjing Jiang, Jing Li, Xiao Lu, Cheng Gong, Lin Zhang, and Hong Liao
Atmos. Chem. Phys., 21, 2601–2613,Short summary
This study demonstrates that the intensity of the western Pacific subtropical high (WPSH), a major synoptic pattern in the northern Pacific during summer, can induce a dipole change in surface ozone pollution over eastern China. Ozone concentration increases in the north and decreases in the south during the strong WPSH phase, and vice versa. The change in chemical processes associated with the WPSH change plays a decisive role, whereas the natural emission of ozone precursors accounts for ~ 30 %.
Yilin Chen, Huizhong Shen, Jennifer Kaiser, Yongtao Hu, Shannon L. Capps, Shunliu Zhao, Amir Hakami, Jhih-Shyang Shih, Gertrude K. Pavur, Matthew D. Turner, Daven K. Henze, Jaroslav Resler, Athanasios Nenes, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Tianfeng Chai, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, and Armistead G. Russell
Atmos. Chem. Phys., 21, 2067–2082,Short summary
Ammonia (NH3) emissions can exert adverse impacts on air quality and ecosystem well-being. NH3 emission inventories are viewed as highly uncertain. Here we optimize the NH3 emission estimates in the US using an air quality model and NH3 measurements from the IASI satellite instruments. The optimized NH3 emissions are much higher than the National Emissions Inventory estimates in April. The optimized NH3 emissions improved model performance when evaluated against independent observation.
Bo Zhang, Hongyu Liu, James H. Crawford, Gao Chen, T. Duncan Fairlie, Scott Chambers, Chang-Hee Kang, Alastair G. Williams, Kai Zhang, David B. Considine, Melissa P. Sulprizio, and Robert M. Yantosca
Atmos. Chem. Phys., 21, 1861–1887,Short summary
We simulate atmospheric 222Rn using the GEOS-Chem model to improve understanding of 222Rn emissions and characterize convective transport in the model. We demonstrate the potential of a customized global 222Rn emission scenario to improve simulated surface 222Rn concentrations and seasonality. We assess convective transport using observed 222Rn vertical profiles. Results have important implications for using chemical transport models to interpret the transport of trace gases and aerosols.
Fei Jiang, Hengmao Wang, Jing M. Chen, Weimin Ju, Xiangjun Tian, Shuzhuang Feng, Guicai Li, Zhuoqi Chen, Shupeng Zhang, Xuehe Lu, Jane Liu, Haikun Wang, Jun Wang, Wei He, and Mousong Wu
Atmos. Chem. Phys., 21, 1963–1985,Short summary
We present a 6-year inversion from 2010 to 2015 for the global and regional carbon fluxes using only the GOSAT XCO2 retrievals. We find that the XCO2 retrievals could significantly improve the modeling of atmospheric CO2 concentrations and that the inferred interannual variations in the terrestrial carbon fluxes in most land regions have a better relationship with the changes in severe drought area or leaf area index, or are more consistent with the previous estimates about drought impact.
Guilherme F. Camarinha-Neto, Julia C. P. Cohen, Cléo Q. Dias-Júnior, Matthias Sörgel, José Henrique Cattanio, Alessandro Araújo, Stefan Wolff, Paulo A. F. Kuhn, Rodrigo A. F. Souza, Luciana V. Rizzo, and Paulo Artaxo
Atmos. Chem. Phys., 21, 339–356,Short summary
It was observed that friagem phenomena (incursion of cold waves from the high latitudes of the Southern Hemisphere to the Amazon region), very common in the dry season of the Amazon region, produced significant changes in microclimate and atmospheric chemistry. Moreover, the effects of the friagem change the surface O3 and CO2 mixing ratios and therefore interfere deeply in the microclimatic conditions and the chemical composition of the atmosphere above the rainforest.
Xinrui Ge, Martijn Schaap, Richard Kranenburg, Arjo Segers, Gert Jan Reinds, Hans Kros, and Wim de Vries
Atmos. Chem. Phys., 20, 16055–16087,Short summary
This article is about improving the modeling of agricultural ammonia emissions. By considering land use, meteorology and agricultural practices, ammonia emission totals officially reported by countries are distributed in space and time. We illustrated the first step for a better understanding of the variability of ammonia emission, with the possibility of being applied at a European scale, which is of great significance for ammonia budget research and future policy-making.
Ashok K. Luhar, David M. Etheridge, Zoë M. Loh, Julie Noonan, Darren Spencer, Lisa Smith, and Cindy Ong
Atmos. Chem. Phys., 20, 15487–15511,Short summary
With the sharp rise in coal seam gas (CSG) production in Queensland’s Surat Basin, there is much interest in quantifying methane emissions from this area and from unconventional gas production in general. We develop and apply a regional Bayesian inverse model that uses hourly methane concentration data from two sites and modelled backward dispersion to quantify emissions. The model requires a narrow prior and suggests that the emissions from the CSG areas are 33% larger than bottom-up estimates.
Wayne M. Angevine, Jeff Peischl, Alice Crawford, Christopher P. Loughner, Ilana B. Pollack, and Chelsea R. Thompson
Atmos. Chem. Phys., 20, 11855–11868,Short summary
Emissions of air pollutants must be known for a wide variety of applications. Different methods of estimating emissions often disagree substantially. In this study, we apply standard methods to a well-known source, a power plant. We explore the uncertainty implied by the different answers that come from the different methods, different samples taken over several years, and different pollutants. We find that the overall uncertainty of emissions estimates is about 30 %.
Peter Huszar, Jan Karlický, Jana Ďoubalová, Tereza Nováková, Kateřina Šindelářová, Filip Švábik, Michal Belda, Tomáš Halenka, and Michal Žák
Atmos. Chem. Phys., 20, 11655–11681,Short summary
The paper shows how extreme meteorological conditions change due to the urban land-cover forcing and how this translates to the impact on the extreme air pollution over central European cities. It focuses on ozone, nitrogen dioxide, and particulate matter with a diameter of less than 2.5 μm and shows that, while for the extreme daily maximum 8 h ozone, changes are same as for the mean ones, much larger modifications are calculated for extreme NO2 and PM2.5 compared to their mean changes.
Lang Wang, Amos P. K. Tai, Chi-Yung Tam, Mehliyar Sadiq, Peng Wang, and Kevin K. W. Cheung
Atmos. Chem. Phys., 20, 11349–11369,Short summary
We investigate the effects of future land use and land cover change (LULCC) on surface ozone air quality worldwide and find that LULCC can significantly influence ozone in North America and Europe via modifying surface energy balance, boundary-layer meteorology, and regional circulation. The strength of such “biogeophysical effects” of LULCC is strongly dependent on forest type and generally greater than the “biogeochemical effects” via changing deposition and emission fluxes alone.
Jinhui Gao, Ying Li, Bin Zhu, Bo Hu, Lili Wang, and Fangwen Bao
Atmos. Chem. Phys., 20, 10831–10844,Short summary
Light extinction of aerosols can decease surface ozone mainly via reducing photochemical production of ozone. However, it also leads to high levels of ozone aloft being entrained down to the surface which partly counteracts the reduction in surface ozone. The impact of aerosols is more sensitive to local ozone, which suggests that while controlling the levels of aerosols, controlling the local ozone precursors is an effective way to suppress the increase of ozone over China at present.
Junhua Liu, Jose M. Rodriguez, Luke D. Oman, Anne R. Douglass, Mark A. Olsen, and Lu Hu
Atmos. Chem. Phys., 20, 6417–6433,Short summary
Our paper quantifies and identifies the importance of stratospheric ozone influence on the tropospheric ozone IAV in Northern Hemisphere mid-high latitudes. Our analysis provides an in-depth understanding of how 3-D dynamics influences the O3 redistribution in the troposphere. These findings are particularly important considering the potential changes in these dynamical conditions in the future as a result of climate change
Jun Park and Hyun Mee Kim
Atmos. Chem. Phys., 20, 5175–5195,Short summary
Observation network experiments were conducted to optimize the surface CO2 flux in Asia. The impacts of the redistribution of and additions to the existing observation network were evaluated. The addition experiments revealed that considering both the normalized self-sensitivity and ecoregion information can yield better simulated surface CO2 fluxes compared to random addition. This study provides useful information for future observation network design to estimate the surface CO2 flux.
Meng Gao, Jinhui Gao, Bin Zhu, Rajesh Kumar, Xiao Lu, Shaojie Song, Yuzhong Zhang, Beixi Jia, Peng Wang, Gufran Beig, Jianlin Hu, Qi Ying, Hongliang Zhang, Peter Sherman, and Michael B. McElroy
Atmos. Chem. Phys., 20, 4399–4414,Short summary
A regional fully coupled meteorology–chemistry model, Weather Research and Forecasting model with Chemistry (WRF-Chem), was employed to study the seasonality of ozone (O3) pollution and its sources in both China and India.
Ryan J. Pound, Tomás Sherwen, Detlev Helmig, Lucy J. Carpenter, and Mat J. Evans
Atmos. Chem. Phys., 20, 4227–4239,Short summary
Ozone is an important pollutant with impacts on health and the environment. Ozone is lost to plants, land and the oceans. Loss to the ocean is slow compared to all other types of land cover and has not received as much attention. We build on previous work to more accurately model ozone loss to the ocean. We find changes in the concentration of ozone over the oceans, notably the Southern Ocean, which improves model performance.
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Our work pioneered land-use machine learning methods for developing link-level emission inventories, utilizing hourly traffic profiles, including volume, speed, and fleet mix, obtained from the governmental intercity highway monitoring network in the "capital circles" of China. This research provides a platform to realize the near-real-time process of establishing high-resolution vehicle emission inventories for policy makers to engage in sophisticated traffic management.
Our work pioneered land-use machine learning methods for developing link-level emission...