Articles | Volume 19, issue 9
| Highlight paper
08 May 2019
Research article | Highlight paper | 08 May 2019
Heterogeneous sulfate aerosol formation mechanisms during wintertime Chinese haze events: air quality model assessment using observations of sulfate oxygen isotopes in Beijing
Jingyuan Shao et al.
Shaojie Song, Meng Gao, Weiqi Xu, Jingyuan Shao, Guoliang Shi, Shuxiao Wang, Yuxuan Wang, Yele Sun, and Michael B. McElroy
Atmos. Chem. Phys., 18, 7423–7438,Short summary
Severe haze events occur frequently over northern China, especially in winter. Acidity plays a critical role in the formation of secondary PM2.5 and its toxicity. Using field measurements of gases and particles to critically evaluate two thermodynamic models routinely employed to determine particle acidity, we found that China's winter haze particles are generally within a moderately acidic range (pH 4–5) and not highly acidic (0) or neutral (7) as has been previously reported in the literature.
Zhiqiang Zhang, Yele Sun, Chun Chen, Bo You, Aodong Du, Weiqi Xu, Yan Li, Zhijie Li, Lu Lei, Wei Zhou, Jiaxing Sun, Yanmei Qiu, Lianfang Wei, Pingqing Fu, and Zifa Wang
Atmos. Chem. Phys., 22, 10409–10423,Short summary
We present a comprehensive characterization of water-soluble organic aerosol and the first mass spectral characterization of water-insoluble organic aerosol in the cold season in Beijing by integrating online and offline aerosol mass spectrometer measurements. WSOA comprised dominantly secondary OA and showed large changes during the transition season from autumn to winter. WIOA was characterized by prominent hydrocarbon ions series, low oxidation states, and significant day–night differences.
Xueyin Ruan, Chun Zhao, Rahul A. Zaveri, Pengzhen He, Xinming Wang, Jingyuan Shao, and Lei Geng
Geosci. Model Dev., 15, 6143–6164,Short summary
Accurate prediction of aerosol pH in chemical transport models is essential to aerosol modeling. This study examines the performance of the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) on aerosol pH predictions and the sensitivities to emissions of nonvolatile cations and NH3, aerosol-phase state assumption, and heterogeneous sulfate production. Temporal evolution of aerosol pH during haze cycles in Beijing and the driving factors are also presented and discussed.
Daniel J. Varon, Daniel J. Jacob, Melissa Sulprizio, Lucas A. Estrada, William B. Downs, Lu Shen, Sarah E. Hancock, Hannah Nesser, Zhen Qu, Elise Penn, Zichong Chen, Xiao Lu, Alba Lorente, Ashutosh Tewari, and Cynthia A. Randles
Geosci. Model Dev., 15, 5787–5805,Short summary
Reducing atmospheric methane emissions is critical to slow near-term climate change. Globally surveying satellite instruments like the TROPOspheric Monitoring Instrument (TROPOMI) have unique capabilities for monitoring atmospheric methane around the world. Here we present a user-friendly cloud-computing tool that enables researchers and stakeholders to quantify methane emissions across user-selected regions of interest using TROPOMI satellite observations.
Viral Shah, Daniel J. Jacob, Ruijun Dang, Lok N. Lamsal, Sarah A. Strode, Stephen D. Steenrod, K. Folkert Boersma, Sebastian D. Eastham, Thibaud M. Fritz, Chelsea Thompson, Jeff Peischl, Ilann Bourgeois, Ilana B. Pollack, Benjamin A. Nault, Ronald C. Cohen, Pedro Campuzano-Jost, Jose L. Jimenez, Simone T. Andersen, Lucy J. Carpenter, Tomás Sherwen, and Mat J. Evans
Background NOx affects global tropospheric chemistry and the retrieval and interpretation of satellite NO2 measurements. We use aircraft measurements to evaluate the simulation of NOx in global atmospheric chemistry models. We find that recycling of NOx from its reservoirs over the oceans is faster than that simulated in the models, resulting in large increases in simulated tropospheric ozone and OH. Over the US, background NO2 contributes the majority of the tropospheric NO2 column in summer.
Zhuang Jiang, Joel Savarino, Becky Alexander, Joseph Erbland, Jean-Luc Jaffrezo, and Lei Geng
The Cryosphere, 16, 2709–2724,Short summary
A record of year-round atmospheric nitrate isotopic composition along with snow nitrate isotopic data from Summit, Greenland, revealed apparent enrichments in nitrogen isotopes in snow nitrate compared to atmospheric nitrate, in addition to a relatively smaller degree of changes in oxygen isotopes. The results suggest that at this site post-depositional processing takes effect, which should be taken into account when interpreting ice-core nitrate isotope records.
Haolin Wang, Xiao Lu, Daniel J. Jacob, Owen R. Cooper, Kai-Lan Chang, Ke Li, Meng Gao, Yiming Liu, Bosi Sheng, Kai Wu, Tongwen Wu, Jie Zhang, Bastien Sauvage, Philippe Nédélec, Romain Blot, and Shaojia Fan
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We report significant global tropospheric ozone increases in 1995–2017 based on extensive aircraft and ozonesonde observations. Using GEOS-Chem multi-decadal global simulations, we find that changes in global anthropogenic emissions, in particular the rapid increases in aircraft emissions, contribute significantly to the increases in tropospheric ozone and resulting radiative impact.
Qianjie Chen, Jessica Mirrielees, Sham Thanekar, Nicole Loeb, Rachel Kirpes, Lucia Upchurch, Anna Barget, Nurun Lata, Angela Raso, Stephen McNamara, Swarup China, Patricia Quinn, Andrew Ault, Aaron Kennedy, Paul Shepson, Jose Fuentes, and Kerri Pratt
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
During a spring field study in the coastal Arctic, ultrafine particles were enhanced during high wind speeds and coarse mode particles were reduced during blowing snow. Observed blowing snow was over-predicted by the commonly used parametrization. Sea spray aerosols produced by sea ice leads affected the composition of aerosols and snowpack. An improved understanding of aerosol emissions from leads and blowing snow is critical to predict the future climate of the rapidly warming Arctic.
Yanzhi Cao, Zhuang Jiang, Becky Alexander, Jihong Cole-Dai, Joel Savarino, Joseph Erbland, and Lei Geng
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We investigate the potential of ice-core preserved nitrate isotopes as proxies of stratospheric ozone variability by measuring nitrate isotopes in a shallow ice core from the South Pole. The large variability of snow accumulation rate and its slight increase after the 1970s masked any signals caused by ozone hole. Meanwhile, the nitrate oxygen isotope decrease may reflect changes in the atmospheric oxidation environment in the Southern Ocean.
Wei Li and Yuxuan Wang
Atmos. Chem. Phys., 22, 7843–7859,Short summary
Fine dust is an important component of PM2.5 and can be largely modulated by droughts. In contrast to the increase in dust in the southwest USA where major dust sources are located, dust in the southeast USA is affected more by long-range transport from Africa and decreases under droughts. Both the transport and emissions of African dust are weakened when the southeast USA is under droughts, which reveals how regional-scale droughts can influence aerosol abundance through long-range transport.
Yuxuan Wang, Nan Lin, Wei Li, Alex Guenther, Joey C. Y. Lam, Amos P. K. Tai, Mark J. Potosnak, and Roger Seco
Drought can impose large changes on biogenic isoprene emissions. In-situ field observations of isoprene emissions under droughts are confined by spatial coverage, thus providing limited constraints. We derived a drought stress factor based on satellite formaldehyde data for MEGAN2.1 in GEOS-Chem model using water stress and temperature. This factor reduces the overestimation of isoprene emissions under severe droughts and improves the simulated ozone and organic aerosol responses to droughts.
Jiaxing Sun, Yele Sun, Conghui Xie, Weiqi Xu, Chun Chen, Zhe Wang, Lei Li, Xubing Du, Fugui Huang, Yan Li, Zhijie Li, Xiaole Pan, Nan Ma, Wanyun Xu, Pingqing Fu, and Zifa Wang
Atmos. Chem. Phys., 22, 7619–7630,Short summary
We analyzed the chemical composition and mixing state of BC-containing particles at urban and rural sites in winter in the North China Plain and evaluated their impact on light absorption enhancement. BC was dominantly mixed with organic carbon, nitrate, and sulfate, and the mixing state evolved significantly as a function of relative humidity (RH) at both sites. The absorption enhancement depended strongly on coated secondary inorganic aerosol and was up to ~1.3–1.4 during aging processes.
Chenhong Zhou, Fan Wang, Yike Guo, Cheng Liu, Dongsheng Ji, Yuesi Wang, Xiaobin Xu, Xiao Lu, Yan Wang, Gregory Carmichael, and Meng Gao
Earth Syst. Sci. Data Discuss.,
Manuscript not accepted for further reviewShort summary
We develop an eXtreme Gradient Boosting (XGBoost) model integrating high-resolution meteorological data, satellite retrievals of trace gases, etc. to provide reconstructed daily ground-level O3 over 2005–2021 in China. It can facilitate climatological, ecological, and health research. The dataset is freely available at Zenodo (https://zenodo.org/record/6507706#.Yo8hKujP13g; Zhou, 2022).
Junjun Deng, Hao Ma, Xinfeng Wang, Shujun Zhong, Zhimin Zhang, Jialei Zhu, Yanbing Fan, Wei Hu, Libin Wu, Xiaodong Li, Lujie Ren, Chandra Mouli Pavuluri, Xiaole Pan, Yele Sun, Zifa Wang, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 22, 6449–6470,Short summary
Light-absorbing brown carbon (BrC) plays an important role in climate change and atmospheric chemistry. Here we investigated the seasonal and diurnal variations in water-soluble BrC in PM2.5 in the megacity Tianjin in coastal China. Results of the source apportionments from the combination with organic molecular compositions and optical properties of water-soluble BrC reveal a large contribution from primary bioaerosol particles to BrC in the urban atmosphere.
Elizabeth Renee Klovenski, Yuxuan Wang, Susanne Elizabeth Bauer, Kostas Tsigaridis, Greg Faluvegi, Igor Aleinov, Nancy Y. Kiang, Alex Guenther, Xiaoyan Jiang, Wei Li, and Nan Lin
Severe drought stresses vegetation and causes reduced emission of isoprene. We study the impact of including a new isoprene drought stress (yd) parameterization into NASA GISS ModelE called (DroughtStress_ModelE), which is specifically tuned for ModelE. Inclusion of yd leads to better simulated isoprene emissions at the MOFLUX site during the severe drought of 2012, reduced overestimation of OMI satellite ΩHCHO (formaldehyde column) and improved simulated O3 (ozone) during drought.
Cheng He, Xiao Lu, Haolin Wang, Haichao Wang, Yan Li, Guowen He, Yuanping He, Yurun Wang, Youlang Zhang, Yiming Liu, Qi Fan, and Shaojia Fan
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We report that nocturnal ozone enhancement (NOE) events are observed at a high annual frequency of 41 % over 800 sites over China in 2014–2019, about 50 % larger than that over Europe and US. High daytime ozone provides rich ozone source in the nighttime residual layer, determining the overall high frequency of NOE events in China, and then the enhanced atmospheric mixing triggers NOE events by allowing the ozone-rich air in the residual layer to be mixed into the nighttime boundary layer.
Zichong Chen, Daniel Jacob, Hannah Nesser, Melissa Sulprizio, Alba Lorente, Daniel Varon, Xiao Lu, Lu Shen, Zhen Qu, Elise Penn, and Xueying Yu
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort 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-gas’ energy transition in China. However, this small loss rate can be misleading given China’s high gas imports.
Jingnan Shi, Juan Hong, Nan Ma, Qingwei Luo, Yao He, Hanbing Xu, Haobo Tan, Qiaoqiao Wang, Jiangchuan Tao, Yaqing Zhou, Shuang Han, Long Peng, Linhong Xie, Guangsheng Zhou, Wanyun Xu, Yele Sun, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 4599–4613,Short summary
In this study, we investigated the hygroscopicity of submicron aerosols at a rural site in the North China Plain during the winter of 2018, using a HTDMA and a CV-ToF-ACSM. We observed differences in aerosol hygroscopicity during two distinct episodes with different primary emissions and secondary aerosol formation processes. These results provide an improved understanding of the complex influence of sources and aerosol evolution processes on their hygroscopicity.
Han Zang, Yue Zhao, Juntao Huo, Qianbiao Zhao, Qingyan Fu, Yusen Duan, Jingyuan Shao, Cheng Huang, Jingyu An, Likun Xue, Ziyue Li, Chenxi Li, and Huayun Xiao
Atmos. Chem. Phys., 22, 4355–4374,Short summary
Particulate nitrate plays an important role in wintertime haze pollution in eastern China, yet quantitative constraints on detailed nitrate formation mechanisms remain limited. Here we quantified the contributions of the heterogeneous N2O5 hydrolysis (66 %) and gas-phase OH + NO2 reaction (32 %) to nitrate formation in this region and identified the atmospheric oxidation capacity (i.e., availability of O3 and OH radicals) as the driving factor of nitrate formation from both processes.
Mengying Li, Shaocai Yu, Xue Chen, Zhen Li, Yibo Zhang, Zhe Song, Weiping Liu, Pengfei Li, Xiaoye Zhang, Meigen Zhang, Yele Sun, Zirui Liu, Caiping Sun, Jingkun Jiang, Shuxiao Wang, Benjamin Murphy, Kiran Alapaty, Rohit Mathur, Daniel Rosenfeld, and John Seinfeld
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
This study constructed an emission inventory of Condensable particulate matter (CPM) in China with a focus on organic aerosols (OA) based on collected CPM emission information. Results show that OA emissions are enhanced twofold after the inclusion of CPM in a new China inventory for the years 2014 and 2017. Sensitivity cases demonstrated the significant contributions of CPM emissions from stationary combustion and mobile sources to POA, SOA, and total OA concentrations.
Claudia Bernier, Yuxuan Wang, Guillaume Gronoff, Timothy Berkoff, K. Emma Knowland, John Sullivan, Ruben Delgado, Vanessa Caicedo, and Brian Carroll
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Coastal regions are susceptible to variable and high ozone which is difficult to simulate. We developed a method to characterize large datasets of multi-dimensional measurements from lidar instruments taken in coastal regions. Using the clustered ozone groups, we evaluated model performance in simulating the coastal ozone variability vertically and diurnally. The approach allowed us to pinpoint areas where the models succeed simulating coastal ozone and areas where there are still gaps.
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.
Lu Shen, Ritesh Gautam, Mark Omara, Daniel Zavala-Araiza, Joannes Maasakkers, Tia Scarpelli, Alba Lorente, David Lyon, Jianxiong Sheng, Daniel Varon, Hannah Nesser, Zhen Qu, Xiao Lu, Melissa Sulprizio, Steven Hamburg, and Daniel Jacob
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We use 22 months of TROPOMI satellite observations to quantity methane emissions from the oil and natural gas sector in the US and Canada at the scale of both individual basins as well as country-wide aggregates. We find that O/G related methane emissions are underestimated in these inventories by 80 % for the US and 40 % for Canada, and 70 % of the underestimate in the US is from 5 O/G basins, including Permian, Haynesville, Anadarko, Eagle Ford and Barnett.
Kathryn D. Kulju, Stephen M. McNamara, Qianjie Chen, Hannah S. Kenagy, Jacinta Edebeli, Jose D. Fuentes, Steven B. Bertman, and Kerri A. Pratt
Atmos. Chem. Phys., 22, 2553–2568,Short summary
N2O5 uptake by chloride-containing surfaces produces ClNO2, which photolyzes, producing NO2 and highly reactive Cl radicals that impact air quality. In the inland urban atmosphere, ClNO2 was elevated during lower air turbulence and over snow-covered ground, from snowpack ClNO2 production. N2O5 and ClNO2 levels were lowest, on average, during rainfall and fog because of scavenging, with N2O5 scavenging by fog droplets likely contributing to observed increased particulate nitrate concentrations.
Dianyi Li, Drew Shindell, Dian Ding, Xiao Lu, Lin Zhang, and Yuqiang Zhang
Atmos. Chem. Phys., 22, 2625–2638,Short summary
In this study, we applied chemical transport model simulation with the latest annual anthropogenic emission inventory to study the long-term trend of ozone-induced crop production losses from 2010 to 2017 in China. We find that overall the ozone-induced crop production loss in China is significant and the annual average economic losses for wheat, rice, maize, and soybean in China are USD 9.55 billion, USD 8.53 billion, USD 2.23 billion, and USD 1.16 billion respectively, over the 8 years.
Randall V. Martin, Sebastian D. Eastham, Liam Bindle, Elizabeth W. Lundgren, Thomas L. Clune, Christoph A. Keller, William Downs, Dandan Zhang, Robert A. Lucchesi, Melissa P. Sulprizio, Robert M. Yantosca, Yanshun Li, Lucas Estrada, William M. Putman, Benjamin M. Auer, Atanas L. Trayanov, Steven Pawson, and Daniel J. Jacob
Geosci. Model Dev. Discuss.,
Preprint under review for GMDShort summary
Atmospheric chemistry models must be able to operate both online as components of Earth system models and offline as stand-alone models. The widely-used GEOS-Chem model operates both online and offline, but the classic offline version is not suitable for massively parallel simulations. We describe a new generation of the off-line high-performance GEOS-Chem (GCHP) that enables high-resolution simulations on thousands of cores including on the cloud with improved access, performance, and accuracy.
Yuying Wang, Rong Hu, Qiuyan Wang, Zhanqing Li, Maureen Cribb, Yele Sun, Xiaorui Song, Yi Shang, Yixuan Wu, Xin Huang, and Yuxiang Wang
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
The mixing state of size-resolved soot particles and their influencing factors were investigated. The results suggest anthropogenic emissions and aging processes (photochemical and liquid phase chemical reactions) have diverse impacts on the mixing state of soot particles in different modes. Considering that the mixing state of soot particles is crucial to model aerosol absorption, this finding is important to study the warming effect of back carbon aerosols.
William F. Swanson, Chris D. Holmes, William R. Simpson, Kaitlyn Confer, Louis Marelle, Jennie L. Thomas, Lyatt Jaeglé, Becky Alexander, Shuting Zhai, Qianjie Chen, Xuan Wang, and Tomás Sherwen
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Radical bromine molecules are seen at higher concentrations during the Arctic Spring. We use the global model GEOS-Chem to test whether snowpack and wind-blown snow sources can explain high bromine concentrations. We run this model for the entire year of 2015 and compare results to observations of bromine from floating platforms on the Arctic Ocean and at Utqiaġvik. We find that the model performs best when both sources are enabled but may overestimate bromine production in summer and fall.
Chao Yan, Yicheng Shen, Dominik Stolzenburg, Lubna Dada, Ximeng Qi, Simo Hakala, Anu-Maija Sundström, Yishuo Guo, Antti Lipponen, Tom 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. Discuss.,
Revised manuscript accepted for ACPShort summary
Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles. In the urban environment, traffic emission is a major source of primary pollutants, but its contribution to NPF remains under debate. During the COVID-19 lockdown, traffic emissions were significantly reduced, providing a unique chance to examine its relevance to NPF. Based on our comprehensive measurements, we demonstrate an insignificant role of traffic emission in NPF.
Jing Cai, Cheng Wu, Jiandong Wang, Wei Du, Feixue Zheng, Simo Hakala, Xiaolong Fan, Biwu Chu, Lei Yao, Zemin Feng, Yongchun Liu, Yele Sun, Jun Zheng, Chao Yan, Federico Bianchi, Markku Kulmala, Claudia Mohr, and Kaspar R. Daellenbach
Atmos. Chem. Phys., 22, 1251–1269,Short summary
This study investigates the connection between organic aerosol (OA) molecular composition and particle absorptive properties in autumn in Beijing. We find that the molecular properties of OA compounds in different episodes influence particle light absorption properties differently: the light absorption enhancement of black carbon and light absorption coefficient of brown carbon were mostly related to more oxygenated OA (low C number and four O atoms) and aromatics/nitro-aromatics, respectively.
Haiyue Tan, Lin Zhang, Xiao Lu, Yuanhong Zhao, Bo Yao, Robert J. Parker, and Hartmut Boesch
Atmos. Chem. Phys., 22, 1229–1249,Short summary
Methane is the second most important anthropogenic greenhouse gas. Understanding methane emissions and concentration growth over China in the past decade is important to support its mitigation. This study analyzes the contributions of methane emissions from different regions and sources over the globe to methane changes over China in 2007–2018. Our results show strong international transport influences and emphasize the need of intensive methane measurements covering eastern China.
Jiaxing Sun, Zhe Wang, Wei Zhou, Conghui Xie, Cheng Wu, Chun Chen, Tingting Han, Qingqing Wang, Zhijie Li, Jie Li, Pingqing Fu, Zifa Wang, and Yele Sun
Atmos. Chem. Phys., 22, 561–575,Short summary
We analyzed 9-year measurements of BC and aerosol optical properties from 2012 to 2020 in Beijing, China. Our results showed large reductions in BC and light extinction coefficient due to the Clean Air Action Plan. As a response, both SSA and mass extinction efficiency (MEE) showed considerable increases, demonstrating a future challenge in visibility improvement. The primary and secondary BrC was also separated and quantified, and the changes in radiative forcing of BC and BrC were estimated.
Xiao Lu, Daniel J. Jacob, Haolin Wang, Joannes D. Maasakkers, Yuzhong Zhang, Tia R. Scarpelli, Lu Shen, Zhen Qu, Melissa P. Sulprizio, Hannah Nesser, A. Anthony Bloom, Shuang Ma, John R. Worden, Shaojia Fan, Robert J. Parker, Hartmut Boesch, Ritesh Gautam, Deborah Gordon, Michael D. Moran, Frances Reuland, Claudia A. Octaviano Villasana, and Arlyn Andrews
Atmos. Chem. Phys., 22, 395–418,Short summary
We evaluate methane emissions and trends for 2010–2017 in the gridded national emission inventories for the United States, Canada, and Mexico by inversion of in situ and satellite methane observations. We find that anthropogenic methane emissions for all three countries are underestimated in the national inventories, largely driven by oil emissions. Anthropogenic methane emissions in the US peak in 2014, in contrast to the report of a steadily decreasing trend over 2010–2017 from the US EPA.
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.
Yuting Zhang, Hang Liu, Shandong Lei, Wanyun Xu, Yu Tian, Weijie Yao, Xiaoyong Liu, Qi Liao, Jie Li, Chun Chen, Yele Sun, Pingqing Fu, Jinyuan Xin, Junji Cao, Xiaole Pan, and Zifa Wang
Atmos. Chem. Phys., 21, 17631–17648,Short summary
In this study, the authors used a single-particle soot photometer (SP2) to characterize the particle size, mixing state, and optical properties of black carbon aerosols in rural areas of the North China Plain in winter. Relatively warm and high-RH environments (RH > 50 %, −4° < T < 4 °) were more favorable to rBC aging than dry and cold environments (RH < 60 %, T < −8°). The paper emphasizes the importance of meteorological parameters in the mixing state of black carbon.
Shixian Zhai, Daniel J. Jacob, Jared F. Brewer, Ke Li, Jonathan M. Moch, Jhoon Kim, Seoyoung Lee, Hyunkwang Lim, Hyun Chul Lee, Su Keun Kuk, Rokjin J. Park, Jaein I. Jeong, Xuan Wang, Pengfei Liu, Gan Luo, Fangqun Yu, Jun Meng, Randall V. Martin, Katherine R. Travis, Johnathan W. Hair, Bruce E. Anderson, Jack E. Dibb, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jung-Hun Woo, Younha Kim, Qiang Zhang, and Hong Liao
Atmos. Chem. Phys., 21, 16775–16791,Short summary
Geostationary satellite aerosol optical depth (AOD) has tremendous potential for monitoring surface fine particulate matter (PM2.5). Our study explored the physical relationship between AOD and PM2.5 by integrating data from surface networks, aircraft, and satellites with the GEOS-Chem chemical transport model. We quantitatively showed that accurate simulation of aerosol size distributions, boundary layer depths, relative humidity, coarse particles, and diurnal variations in PM2.5 are essential.
Ruqian Miao, Qi Chen, Manish Shrivastava, Youfan Chen, Lin Zhang, Jianlin Hu, Yan Zheng, and Keren Liao
Atmos. Chem. Phys., 21, 16183–16201,Short summary
We apply process-based and observation-constrained schemes to simulate organic aerosol in China and conduct comprehensive model–observation comparisons. The results show that anthropogenic semivolatile and intermediate-volatility organic compounds (SVOCs and IVOCs) are the main sources of secondary organic aerosol (SOA) in polluted regions, for which the residential sector is perhaps the predominant contributor. The hydroxyl radical level is also important for SOA modeling in polluted regions.
Liam Bindle, Randall V. Martin, Matthew J. Cooper, Elizabeth W. Lundgren, Sebastian D. Eastham, Benjamin M. Auer, Thomas L. Clune, Hongjian Weng, Jintai Lin, Lee T. Murray, Jun Meng, Christoph A. Keller, William M. Putman, Steven Pawson, and Daniel J. Jacob
Geosci. Model Dev., 14, 5977–5997,Short summary
Atmospheric chemistry models like GEOS-Chem are versatile tools widely used in air pollution and climate studies. The simulations used in such studies can be very computationally demanding, and thus it is useful if the model can simulate a specific geographic region at a higher resolution than the rest of the globe. Here, we implement, test, and demonstrate a new variable-resolution capability in GEOS-Chem that is suitable for simulations conducted on supercomputers.
Sihui Jiang, Fang Zhang, Jingye Ren, Lu Chen, Xing Yan, Jieyao Liu, Yele Sun, and Zhanqing Li
Atmos. Chem. Phys., 21, 14293–14308,Short summary
New particle formation (NPF) can be a large source of CCN and affect weather and climate. Here we show that the NPF contributes largely to cloud droplet number concentration (Nd) but is suppressed at high particle number concentrations in Beijing due to water vapor competition. We also reveal a considerable impact of primary sources on the evaluation in the urban atmosphere. Our study has great significance for assessing NPF-associated effects on climate in polluted regions.
Zhen Qu, Daniel J. Jacob, Lu Shen, Xiao Lu, Yuzhong Zhang, Tia R. Scarpelli, Hannah Nesser, Melissa P. Sulprizio, Joannes D. Maasakkers, A. Anthony Bloom, John R. Worden, Robert J. Parker, and Alba L. Delgado
Atmos. Chem. Phys., 21, 14159–14175,Short summary
The recent launch of TROPOMI offers an unprecedented opportunity to quantify the methane budget from a top-down perspective. We use TROPOMI and the more mature GOSAT methane observations to estimate methane emissions and get consistent global budgets. However, TROPOMI shows biases over regions where surface albedo is small and provides less information for the coarse-resolution inversion due to the larger error correlations and spatial variations in the number of observations.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick R. Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys., 21, 13973–13996,Short summary
Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Andreas Tilgner, Thomas Schaefer, Becky Alexander, Mary Barth, Jeffrey L. Collett Jr., Kathleen M. Fahey, Athanasios Nenes, Havala O. T. Pye, Hartmut Herrmann, and V. Faye McNeill
Atmos. Chem. Phys., 21, 13483–13536,Short summary
Feedbacks of acidity and atmospheric multiphase chemistry in deliquesced particles and clouds are crucial for the tropospheric composition, depositions, climate, and human health. This review synthesizes the current scientific knowledge on these feedbacks using both inorganic and organic aqueous-phase chemistry. Finally, this review outlines atmospheric implications and highlights the need for future investigations with respect to reducing emissions of key acid precursors in a changing world.
Zhuang Jiang, Becky Alexander, Joel Savarino, Joseph Erbland, and Lei Geng
The Cryosphere, 15, 4207–4220,Short summary
We used a snow photochemistry model (TRANSITS) to simulate the seasonal nitrate snow profile at Summit, Greenland. Comparisons between model outputs and observations suggest that at Summit post-depositional processing is active and probably dominates the snowpack δ15N seasonality. We also used the model to assess the degree of snow nitrate loss and the consequences in its isotopes at present and in the past, which helps for quantitative interpretations of ice-core nitrate records.
Hong Ren, Wei Hu, Lianfang Wei, Siyao Yue, Jian Zhao, Linjie Li, Libin Wu, Wanyu Zhao, Lujie Ren, Mingjie Kang, Qiaorong Xie, Sihui Su, Xiaole Pan, Zifa Wang, Yele Sun, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 21, 12949–12963,Short summary
This study presents vertical profiles of biogenic and anthropogenic secondary organic aerosols (SOAs) in the urban boundary layer based on a 325 m tower in Beijing in late summer. The increases in the isoprene and toluene SOAs with height were found to be more related to regional transport, whereas the decrease in those from monoterpenes and sesquiterpene were more subject to local emissions. Such complicated vertical distributions of SOA should be considered in future modeling work.
Yang Yang, Minqiang Zhou, Ting Wang, Bo Yao, Pengfei Han, Denghui Ji, Wei Zhou, Yele Sun, Gengchen Wang, and Pucai Wang
Atmos. Chem. Phys., 21, 11741–11757,Short summary
This study introduces the in situ CO2 measurement system installed in Beijing (urban), Xianghe (suburban), and Xinglong (rural) in North China for the first time. The spatial and temporal variations in CO2 mole fractions at the three sites between June 2018 and April 2020 are discussed on both seasonal and diurnal scales.
Youwen Sun, Hao Yin, Cheng Liu, Emmanuel Mahieu, Justus Notholt, Yao Té, Xiao Lu, Mathias Palm, Wei Wang, Changgong Shan, Qihou Hu, Min Qin, Yuan Tian, and Bo Zheng
Atmos. Chem. Phys., 21, 11759–11779,Short summary
The variability, sources, and transport of ethane (C2H6) over eastern China from 2015 to 2020 were studied using ground-based Fourier transform infrared (FTIR) spectroscopy and GEOS-Chem simulations. C2H6 variability is driven by both meteorological and emission factors. The reduction in C2H6 in recent years over eastern China points to air quality improvement in China.
Yadong Lei, Xu Yue, Hong Liao, Lin Zhang, Yang Yang, Hao Zhou, Chenguang Tian, Cheng Gong, Yimian Ma, Lan Gao, and Yang Cao
Atmos. Chem. Phys., 21, 11531–11543,Short summary
We present the first estimate of ozone enhancement by fire emissions through ozone–vegetation interactions using a fully coupled chemistry–vegetation model (GC-YIBs). In fire-prone areas, fire-induced ozone causes a positive feedback to surface ozone mainly because of the inhibition effects on stomatal conductance.
Qiaorong Xie, Sihui Su, Jing Chen, Yuqing Dai, Siyao Yue, Hang Su, Haijie Tong, Wanyu Zhao, Lujie Ren, Yisheng Xu, Dong Cao, Ying Li, Yele Sun, Zifa Wang, Cong-Qiang Liu, Kimitaka Kawamura, Guibin Jiang, Yafang Cheng, and Pingqing Fu
Atmos. Chem. Phys., 21, 11453–11465,Short summary
This study investigated the role of nighttime chemistry during Chinese New Year's Eve that enhances the formation of nitrooxy organosulfates in the aerosol phase. Results show that anthropogenic precursors, together with biogenic ones, considerably contribute to the formation of low-volatility nitrooxy OSs. Our study provides detailed molecular composition of firework-related aerosols, which gives new insights into the physicochemical properties and potential health effects of urban aerosols.
Meng Gao, Yang Yang, Hong Liao, Bin Zhu, Yuxuan Zhang, Zirui Liu, Xiao Lu, Chen Wang, Qiming Zhou, Yuesi Wang, Qiang Zhang, Gregory R. Carmichael, and Jianlin Hu
Atmos. Chem. Phys., 21, 11405–11421,Short summary
Light absorption and radiative forcing of black carbon (BC) is influenced by both BC itself and its interactions with other aerosol chemical compositions. In this study, we used the online coupled WRF-Chem model to examine how emission control measures during the Asian-Pacific Economic Cooperation (APEC) conference affect the mixing state and light absorption of BC and the associated implications for BC-PBL interactions.
Ying Wei, Xueshun Chen, Huansheng Chen, Yele Sun, Wenyi Yang, Huiyun Du, Qizhong Wu, Dan Chen, Xiujuan Zhao, Jie Li, and Zifa Wang
Geosci. Model Dev., 14, 4411–4428,Short summary
The sub-grid particle formation (SGPF) in plumes plays an important role in air pollution and climate. We coupled an SGPF scheme to a chemical transport model with an aerosol microphysics module and applied it to investigate the SGPF impact over China. The scheme clearly improved the model performance in simulating aerosol components and particle number at typical sites influenced by point sources. The results indicate the significant effects of SGPF on aerosol particles in industrial areas.
Jun Meng, Randall V. Martin, Paul Ginoux, Melanie Hammer, Melissa P. Sulprizio, David A. Ridley, and Aaron van Donkelaar
Geosci. Model Dev., 14, 4249–4260,Short summary
Dust emissions in models, for example, GEOS-Chem, have a strong nonlinear dependence on meteorology, which means dust emission strengths calculated from different resolution meteorological fields are different. Offline high-resolution dust emissions with an optimized global dust strength, presented in this work, can be implemented into GEOS-Chem as offline emission inventory so that it could promote model development by harmonizing dust emissions across simulations of different resolutions.
Xueshun Chen, Fangqun Yu, Wenyi Yang, Yele Sun, Huansheng Chen, Wei Du, Jian Zhao, Ying Wei, Lianfang Wei, Huiyun Du, Zhe Wang, Qizhong Wu, Jie Li, Junling An, and Zifa Wang
Atmos. Chem. Phys., 21, 9343–9366,Short summary
Atmospheric aerosol particles have significant climate and health effects that depend on aerosol size, composition, and mixing state. A new global-regional nested aerosol model with an advanced particle microphysics module and a volatility basis set organic aerosol module was developed to simulate aerosol microphysical processes. Simulations strongly suggest the important role of anthropogenic organic species in particle formation over the areas influenced by anthropogenic sources.
Youwen Sun, Hao Yin, Yuan Cheng, Qianggong Zhang, Bo Zheng, Justus Notholt, Xiao Lu, Cheng Liu, Yuan Tian, and Jianguo Liu
Atmos. Chem. Phys., 21, 9201–9222,Short summary
We quantified the variability, source, and transport of urban CO over the Himalayas and Tibetan Plateau (HTP) by using measurement, model simulation, and the analysis of meteorological fields. Urban CO over the HTP is dominated by anthropogenic and biomass burning emissions from local, South Asia and East Asia, and oxidation sources. The decreasing trends in surface CO since 2015 in most cities over the HTP are attributed to the reduction in local and transported CO emissions in recent years.
Kun Wang, Shohei Hattori, Mang Lin, Sakiko Ishino, Becky Alexander, Kazuki Kamezaki, Naohiro Yoshida, and Shichang Kang
Atmos. Chem. Phys., 21, 8357–8376,Short summary
Sulfate aerosols play an important climatic role and exert adverse effects on the ecological environment and human health. In this study, we present the triple oxygen isotopic composition of sulfate from the Mt. Everest region, southern Tibetan Plateau, and decipher the formation mechanisms of atmospheric sulfate in this pristine environment. The results indicate the important role of the S(IV) + O3 pathway in atmospheric sulfate formation promoted by conditions of high cloud water pH.
Siqi Hou, Di Liu, Jingsha Xu, Tuan V. Vu, Xuefang Wu, Deepchandra Srivastava, Pingqing Fu, Linjie Li, Yele Sun, Athanasia Vlachou, Vaios Moschos, Gary Salazar, Sönke Szidat, André S. H. Prévôt, Roy M. Harrison, and Zongbo Shi
Atmos. Chem. Phys., 21, 8273–8292,Short summary
This study provides a newly developed method which combines radiocarbon (14C) with organic tracers to enable source apportionment of primary and secondary fossil vs. non-fossil sources of carbonaceous aerosols at an urban and a rural site of Beijing. The source apportionment results were compared with those by chemical mass balance and AMS/ACSM-PMF methods. Correlations of WINSOC and WSOC with different sources of OC were also performed to elucidate the formation mechanisms of SOC.
Weiqi Xu, Masayuki Takeuchi, Chun Chen, Yanmei Qiu, Conghui Xie, Wanyun Xu, Nan Ma, Douglas R. Worsnop, Nga Lee Ng, and Yele Sun
Atmos. Meas. Tech., 14, 3693–3705,Short summary
Here we developed a method for estimation of particulate organic nitrates (pON) from the measurements of a high-resolution aerosol mass spectrometer coupled with a thermodenuder based on the volatility differences between inorganic nitrate and pON. The results generally had improvements in reducing negative values due to the influences of a high concentration of inorganic nitrate and a constant ratio of NO+ to NO2+ of organic nitrates (RON).
Jiangchuan Tao, Ye Kuang, Nan Ma, Juan Hong, Yele Sun, Wanyun Xu, Yanyan Zhang, Yao He, Qingwei Luo, Linhong Xie, Hang Su, and Yafang Cheng
Atmos. Chem. Phys., 21, 7409–7427,Short summary
The mechanism of secondary aerosol (SA) formation can be affected by relative humidity (RH) and has different influences on the particle CCN activity under different RH conditions. In the North China Plain, we find different responses of CCN activity and enhancements of CCN number concentration to SA formation under different RH conditions. In addition, variations of aerosol mixing state due to SA formation contribute some of the largest uncertainties in predicting CCN number concentration.
Jingsha Xu, Di Liu, Xuefang Wu, Tuan V. Vu, Yanli Zhang, Pingqing Fu, Yele Sun, Weiqi Xu, Bo Zheng, Roy M. Harrison, and Zongbo Shi
Atmos. Chem. Phys., 21, 7321–7341,Short summary
Source apportionment of fine aerosols in an urban site of Beijing used a chemical mass balance (CMB) model. Seven primary sources (industrial/residential coal burning, biomass burning, gasoline/diesel vehicles, cooking and vegetative detritus) explained an average of 75.7 % and 56.1 % of fine OC in winter and summer, respectively. CMB was found to resolve more primary OA sources than AMS-PMF, but the latter apportioned more secondary OA sources.
Youwen Sun, Hao Yin, Cheng Liu, Lin Zhang, Yuan Cheng, Mathias Palm, Justus Notholt, Xiao Lu, Corinne Vigouroux, Bo Zheng, Wei Wang, Nicholas Jones, Changong Shan, Min Qin, Yuan Tian, Qihou Hu, Fanhao Meng, and Jianguo Liu
Atmos. Chem. Phys., 21, 6365–6387,Short summary
This study mapped the drivers of HCHO variability from 2015 to 2019 over eastern China. Hydroxyl (OH) radical production rates from HCHO photolysis were evaluated. The relative contributions of emitted and photochemical sources to the observed HCHO abundance were analyzed. Contributions of various emission sources and geographical regions to the observed HCHO summertime enhancements were determined.
Athanasios Nenes, Spyros N. Pandis, Maria Kanakidou, Armistead G. Russell, Shaojie Song, Petros Vasilakos, and Rodney J. Weber
Atmos. Chem. Phys., 21, 6023–6033,Short summary
Ecosystems and air quality are affected by the dry deposition of inorganic reactive nitrogen (Nr, the sum of ammonium and nitrate). Its large variability is driven by the large difference in deposition velocity of N when in the gas or particle phase. Here we show that aerosol liquid water and acidity, by affecting gas–particle partitioning, modulate the dry deposition velocity of NH3, HNO3, and Nr worldwide. These effects explain the rapid accumulation of nitrate aerosol during haze events.
Steven J. Campbell, Kate Wolfer, Battist Utinger, Joe Westwood, Zhi-Hui Zhang, Nicolas Bukowiecki, Sarah S. Steimer, Tuan V. Vu, Jingsha Xu, Nicholas Straw, Steven Thomson, Atallah Elzein, Yele Sun, Di Liu, Linjie Li, Pingqing Fu, Alastair C. Lewis, Roy M. Harrison, William J. Bloss, Miranda Loh, Mark R. Miller, Zongbo Shi, and Markus Kalberer
Atmos. Chem. Phys., 21, 5549–5573,Short summary
In this study, we quantify PM2.5 oxidative potential (OP), a metric widely suggested as a potential measure of particle toxicity, in Beijing in summer and winter using four acellular assays. We correlate PM2.5 OP with a comprehensive range of atmospheric and particle composition measurements, demonstrating inter-assay differences and seasonal variation of PM2.5 OP. Using multivariate statistical analysis, we highlight specific particle chemical components and sources that influence OP.
Weiqi Xu, Chun Chen, Yanmei Qiu, Ying Li, Zhiqiang Zhang, Eleni Karnezi, Spyros N. Pandis, Conghui Xie, Zhijie Li, Jiaxing Sun, Nan Ma, Wanyun Xu, Pingqing Fu, Zifa Wang, Jiang Zhu, Douglas R. Worsnop, Nga Lee Ng, and Yele Sun
Atmos. Chem. Phys., 21, 5463–5476,Short summary
Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in the North China Plain (NCP) were investigated in summer and winter. Our results showed that organic aerosol (OA) in winter in the NCP is more volatile than that in summer due to enhanced primary emissions from coal combustion and biomass burning. We also found that OA existed mainly as a solid in winter in Beijing but as semisolids in Beijing in summer and Gucheng in winter.
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.
Joannes D. Maasakkers, Daniel J. Jacob, Melissa P. Sulprizio, Tia R. Scarpelli, Hannah Nesser, Jianxiong Sheng, Yuzhong Zhang, Xiao Lu, A. Anthony Bloom, Kevin W. Bowman, John R. Worden, and Robert J. Parker
Atmos. Chem. Phys., 21, 4339–4356,Short summary
We use 2010–2015 GOSAT satellite observations of atmospheric methane over North America in a high-resolution inversion to estimate methane emissions. We find general consistency with the gridded EPA inventory but higher oil and gas production emissions, with oil production emissions twice as large as in the latest EPA Greenhouse Gas Inventory. We find lower wetland emissions than predicted by WetCHARTs and a small increasing trend in the eastern US, apparently related to unconventional oil/gas.
Yuzhong Zhang, Daniel J. Jacob, Xiao Lu, Joannes D. Maasakkers, Tia R. Scarpelli, Jian-Xiong Sheng, Lu Shen, Zhen Qu, Melissa P. Sulprizio, Jinfeng Chang, A. Anthony Bloom, Shuang Ma, John Worden, Robert J. Parker, and Hartmut Boesch
Atmos. Chem. Phys., 21, 3643–3666,Short summary
We use 2010–2018 satellite observations of atmospheric methane to interpret the factors controlling atmospheric methane and its accelerating increase during the period. The 2010–2018 increase in global methane emissions is driven by tropical and boreal wetlands and tropical livestock (South Asia, Africa, Brazil), with an insignificant positive trend in emissions from the fossil fuel sector. The peak methane growth rates in 2014–2015 are also contributed by low OH and high fire emissions.
Peter Sherman, Meng Gao, Shaojie Song, Alex T. Archibald, Nathan Luke Abraham, Jean-François Lamarque, Drew Shindell, Gregory Faluvegi, and Michael B. McElroy
Atmos. Chem. Phys., 21, 3593–3605,Short summary
The aims here are to assess the role of aerosols in India's monsoon precipitation and to determine the relative contributions from Chinese and Indian emissions using CMIP6 models. We find that increased sulfur emissions reduce precipitation, which is primarily dynamically driven due to spatial shifts in convection over the region. A significant increase in precipitation (up to ~ 20 %) is found only when both Indian and Chinese sulfate emissions are regulated.
Yao Wang, Yue Zhao, Yuchen Wang, Jian-Zhen Yu, Jingyuan Shao, Ping Liu, Wenfei Zhu, Zhen Cheng, Ziyue Li, Naiqiang Yan, and Huayun Xiao
Atmos. Chem. Phys., 21, 2959–2980,Short summary
Organosulfates (OSs) are important constituents and tracers of secondary organic aerosols (SOAs) in the atmosphere. Here we characterized the OS species in ambient aerosols in Shanghai, China. We find that the contributions of OSs and SOAs to organic aerosols have increased in recent years and that OS production was largely controlled by the oxidant level (Ox), particularly in summer. We infer that mitigation of Ox pollution can effectively reduce the production of OSs and SOAs in eastern China.
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 %.
Lei Liu, Jian Zhang, Yinxiao Zhang, Yuanyuan Wang, Liang Xu, Qi Yuan, Dantong Liu, Yele Sun, Pingqing Fu, Zongbo Shi, and Weijun Li
Atmos. Chem. Phys., 21, 2251–2265,Short summary
We found that large numbers of light-absorbing primary organic particles with high viscosity, especially tarballs, from domestic coal and biomass burning occurred in rural and even urban hazes in the winter of North China. For the first time, we characterized the atmospheric aging process of these burning-related primary organic particles by microscopic analysis and further evaluated their light absorption enhancement resulting from the “lensing effect” of secondary inorganic coatings.
Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Archit Mehra, Stephen D. Worrall, Asan Bacak, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, William J. Bloss, Tuan Vu, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lujie Ren, W. Joe F. Acton, C. Nicholas Hewitt, Xinming Wang, Pingqing Fu, and Dwayne E. Heard
Atmos. Chem. Phys., 21, 2125–2147,Short summary
To understand how emission controls will impact ozone, an understanding of the sources and sinks of OH and the chemical cycling between peroxy radicals is needed. This paper presents measurements of OH, HO2 and total RO2 taken in central Beijing. The radical observations are compared to a detailed chemistry model, which shows that under low NO conditions, there is a missing OH source. Under high NOx conditions, the model under-predicts RO2 and impacts our ability to model ozone.
Shaojie Song, Tao Ma, Yuzhong Zhang, Lu Shen, Pengfei Liu, Ke Li, Shixian Zhai, Haotian Zheng, Meng Gao, Jonathan M. Moch, Fengkui Duan, Kebin He, and Michael B. McElroy
Atmos. Chem. Phys., 21, 457–481,Short summary
We simulate the atmospheric chemical processes of an important sulfur-containing organic aerosol species, which is produced by the reaction between sulfur dioxide and formaldehyde. We can predict its distribution on a global scale. We find it is particularly rich in East Asia. This aerosol species is more abundant in the colder season partly because of weaker sunlight.
Liya Ma, Yujiao Zhu, Mei Zheng, Yele Sun, Lei Huang, Xiaohuan Liu, Yang Gao, Yanjie Shen, Huiwang Gao, and Xiaohong Yao
Atmos. Chem. Phys., 21, 183–200,Short summary
In this study, we investigate three patterns of new particles growing to CCN (cloud condensation nuclei) size, i.e., one-stage growth and two-stage growth-A and growth-B patterns. Combining the observations of gaseous pollutants and measured or modeled particulate chemical species, the three growth patterns were discussed regarding the spatial heterogeneity, formation of secondary aerosols, and evaporation of semivolatile particulates as was the survival probability of new particles to CCN size.
Erin E. McDuffie, Steven J. Smith, Patrick O'Rourke, Kushal Tibrewal, Chandra Venkataraman, Eloise A. Marais, Bo Zheng, Monica Crippa, Michael Brauer, and Randall V. Martin
Earth Syst. Sci. Data, 12, 3413–3442,Short summary
Global emission inventories are vital to understanding the impacts of air pollution on the environment, human health, and society. We update the open-source Community Emissions Data System (CEDS) to provide global gridded emissions of seven key air pollutants from 1970–2017 for 11 source sectors and multiple fuel types, including coal, solid biofuel, and liquid oil and natural gas. This dataset includes both monthly global gridded emissions and annual national totals.
Zhuang Wang, Cheng Liu, Zhouqing Xie, Qihou Hu, Meinrat O. Andreae, Yunsheng Dong, Chun Zhao, Ting Liu, Yizhi Zhu, Haoran Liu, Chengzhi Xing, Wei Tan, Xiangguang Ji, Jinan Lin, and Jianguo Liu
Atmos. Chem. Phys., 20, 14917–14932,Short summary
Significant stratification of aerosols was observed in North China. Polluted dust dominated above the PBL, and anthropogenic aerosols prevailed within the PBL, which is mainly driven by meteorological conditions. The key role of the elevated dust is to alter atmospheric thermodynamics and stability, causing the suppression of turbulence exchange and a decrease in PBL height, especially during the dissipation stage, thereby inhibiting dissipation of persistent heavy surface haze pollution.
Eloise J. Slater, Lisa K. Whalley, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Leigh R. Crilley, Louisa Kramer, William Bloss, Tuan Vu, Yele Sun, Weiqi Xu, Siyao Yue, Lujie Ren, W. Joe F. Acton, C. Nicholas Hewitt, Xinming Wang, Pingqing Fu, and Dwayne E. Heard
Atmos. Chem. Phys., 20, 14847–14871,Short summary
The paper details atmospheric chemistry in a megacity (Beijing), focussing on radicals which mediate the formation of secondary pollutants such as ozone and particles. Highly polluted conditions were experienced, including the highest ever levels of nitric oxide (NO), with simultaneous radical measurements. Radical concentrations were large during "haze" events, demonstrating active photochemistry. Modelling showed that our understanding of the chemistry at high NOx levels is incomplete.
Jingsha Xu, Shaojie Song, Roy M. Harrison, Congbo Song, Lianfang Wei, Qiang Zhang, Yele Sun, Lu Lei, Chao Zhang, Xiaohong Yao, Dihui Chen, Weijun Li, Miaomiao Wu, Hezhong Tian, Lining Luo, Shengrui Tong, Weiran Li, Junling Wang, Guoliang Shi, Yanqi Huangfu, Yingze Tian, Baozhu Ge, Shaoli Su, Chao Peng, Yang Chen, Fumo Yang, Aleksandra Mihajlidi-Zelić, Dragana Đorđević, Stefan J. Swift, Imogen Andrews, Jacqueline F. Hamilton, Ye Sun, Agung Kramawijaya, Jinxiu Han, Supattarachai Saksakulkrai, Clarissa Baldo, Siqi Hou, Feixue Zheng, Kaspar R. Daellenbach, Chao Yan, Yongchun Liu, Markku Kulmala, Pingqing Fu, and Zongbo Shi
Atmos. Meas. Tech., 13, 6325–6341,Short summary
An interlaboratory comparison was conducted for the first time to examine differences in water-soluble inorganic ions (WSIIs) measured by 10 labs using ion chromatography (IC) and by two online aerosol chemical speciation monitor (ACSM) methods. Major ions including SO42−, NO3− and NH4+ agreed well in 10 IC labs and correlated well with ACSM data. WSII interlab variability strongly affected aerosol acidity results based on ion balance, but aerosol pH computed by ISORROPIA II was very similar.
Chaomin Wang, Bin Yuan, Caihong Wu, Sihang Wang, Jipeng Qi, Baolin Wang, Zelong Wang, Weiwei Hu, Wei Chen, Chenshuo Ye, Wenjie Wang, Yele Sun, Chen Wang, Shan Huang, Wei Song, Xinming Wang, Suxia Yang, Shenyang Zhang, Wanyun Xu, Nan Ma, Zhanyi Zhang, Bin Jiang, Hang Su, Yafang Cheng, Xuemei Wang, and Min Shao
Atmos. Chem. Phys., 20, 14123–14138,Short summary
We utilized a novel online mass spectrometry method to measure the total concentration of higher alkanes at each carbon number at two different sites in China, allowing us to take into account SOA contributions from all isomers for higher alkanes. We found that higher alkanes account for significant fractions of SOA formation at the two sites. The contributions are comparable to or even higher than single-ring aromatics, the most-recognized SOA precursors in urban air.
Junfeng Wang, Jianhuai Ye, Dantong Liu, Yangzhou Wu, Jian Zhao, Weiqi Xu, Conghui Xie, Fuzhen Shen, Jie Zhang, Paul E. Ohno, Yiming Qin, Xiuyong Zhao, Scot T. Martin, Alex K. Y. Lee, Pingqing Fu, Daniel J. Jacob, Qi Zhang, Yele Sun, Mindong Chen, and Xinlei Ge
Atmos. Chem. Phys., 20, 14091–14102,Short summary
We compared the organics in total submicron matter and those coated on BC cores during summertime in Beijing and found large differences between them. Traffic-related OA was associated significantly with BC, while cooking-related OA did not coat BC. In addition, a factor likely originated from primary biomass burning OA was only identified in BC-containing particles. Such a unique BBOA requires further field and laboratory studies to verify its presence and elucidate its properties and impacts.
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.
Ruqian Miao, Qi Chen, Yan Zheng, Xi Cheng, Yele Sun, Paul I. Palmer, Manish Shrivastava, Jianping Guo, Qiang Zhang, Yuhan Liu, Zhaofeng Tan, Xuefei Ma, Shiyi Chen, Limin Zeng, Keding Lu, and Yuanhang Zhang
Atmos. Chem. Phys., 20, 12265–12284,Short summary
In this study we evaluated the model performances for simulating secondary inorganic aerosol (SIA) and organic aerosol (OA) in PM2.5 in China against comprehensive datasets. The potential biases from factors related to meteorology, emission, chemistry, and atmospheric removal are systematically investigated. This study provides a comprehensive understanding of modeling PM2.5, which is important for studies on the effectiveness of emission control strategies.
Viral Shah, Daniel J. Jacob, Jonathan M. Moch, Xuan Wang, and Shixian Zhai
Atmos. Chem. Phys., 20, 12223–12245,Short summary
Cloud water pH affects atmospheric chemistry, and acid rain damages ecosystems. We use model simulations along with observations to present a global view of cloud water and precipitation pH. Sulfuric acid, nitric acid, and ammonia control the pH in the northern midlatitudes, but carboxylic acids and dust cations are important in the tropics and subtropics. The acid inputs to many nitrogen-saturated ecosystems are high enough to cause acidification, with ammonium as the main acidifying species.
Hwajin Kim, Qi Zhang, and Yele Sun
Atmos. Chem. Phys., 20, 11527–11550,Short summary
Severe spring haze and influences of long-range transport in the Seoul metropolitan area (SMA) in March 2019 were investigated. Simultaneous downwind (SMA) and upwind (Beijing) measurements using AMS and ACSM over the same period showed that PM species can be transported in approximately 2 d. Nitrate was the most responsible, and sulfate and two regional-transport-influenced SOAs also contributed. Enhancement of Pb also showed that the haze in the SMA was influenced by the regional transport.
Ke Li, Daniel J. Jacob, Lu Shen, Xiao Lu, Isabelle De Smedt, and Hong Liao
Atmos. Chem. Phys., 20, 11423–11433,Short summary
Surface summer ozone increased in China from 2013 to 2019 despite new governmental efforts targeting ozone pollution. We find that the ozone increase is mostly due to anthropogenic drivers, although meteorology also plays a role. Further analysis for the North China Plain shows that PM2.5 continued to decrease through 2019, while emissions of volatile organic compounds (VOCs) stayed flat. This could explain the anthropogenic increase in ozone, as PM2.5 scavenges the radical precursors of ozone.
Sally S.-C. Wang and Yuxuan Wang
Atmos. Chem. Phys., 20, 11065–11087,Short summary
A model consisting of multiple machine learning algorithms is developed to predict wildfire burned area over the south central US and explains key environmental drivers. The developed model alleviates the issue of unevenly distributed data and predicts burned grids and burned areas with good accuracy. The model reveals climate variability such as relative humidity anomalies and antecedent drought severity contributes the most to the total burned area for winter–spring and summer fire season.
Li Zhang, Meiyun Lin, Andrew O. Langford, Larry W. Horowitz, Christoph J. Senff, Elizabeth Klovenski, Yuxuan Wang, Raul J. Alvarez II, Irina Petropavlovskikh, Patrick Cullis, Chance W. Sterling, Jeff Peischl, Thomas B. Ryerson, Steven S. Brown, Zachary C. J. Decker, Guillaume Kirgis, and Stephen Conley
Atmos. Chem. Phys., 20, 10379–10400,Short summary
Measuring and quantifying the sources of elevated springtime ozone in the southwestern US is challenging but relevant to the implications for control policy. Here we use intensive field measurements and two global models to study ozone sources in the region. We find that ozone from the stratosphere, wildfires, and Asia is an important source of high-ozone events in the region. Our analysis also helps understand the uncertainties in ozone simulations with individual models.
Wanyu Zhao, Hong Ren, Kimitaka Kawamura, Huiyun Du, Xueshun Chen, Siyao Yue, Qiaorong Xie, Lianfang Wei, Ping Li, Xin Zeng, Shaofei Kong, Yele Sun, Zifa Wang, and Pingqing Fu
Atmos. Chem. Phys., 20, 10331–10350,Short summary
Our observations provide detailed information on the abundance and vertical distribution of dicarboxylic acids, oxoacids and α-dicarbonyls in PM2.5 collected at three heights based on a 325 m meteorological tower in Beijing in summer. Our results demonstrate that organic acids at the ground surface are largely associated with local traffic emissions, while long-range atmospheric transport followed by photochemical ageing contributes more in the urban boundary layer than the ground surface.
Xiao Lu, Lin Zhang, Tongwen Wu, Michael S. Long, Jun Wang, Daniel J. Jacob, Fang Zhang, Jie Zhang, Sebastian D. Eastham, Lu Hu, Lei Zhu, Xiong Liu, and Min Wei
Geosci. Model Dev., 13, 3817–3838,Short summary
This study presents the development and evaluation of a new climate chemistry model, BCC-GEOS-Chem v1.0, which couples the GEOS-Chem chemical transport model as an atmospheric chemistry component in the Beijing Climate Center atmospheric general circulation model. A 3-year (2012–2014) simulation of BCC-GEOS-Chem v1.0 shows that the model captures well the spatiotemporal distributions of tropospheric ozone, other gaseous pollutants, and aerosols.
Haipeng Lin, Xu Feng, Tzung-May Fu, Heng Tian, Yaping Ma, Lijuan Zhang, Daniel J. Jacob, Robert M. Yantosca, Melissa P. Sulprizio, Elizabeth W. Lundgren, Jiawei Zhuang, Qiang Zhang, Xiao Lu, Lin Zhang, Lu Shen, Jianping Guo, Sebastian D. Eastham, and Christoph A. Keller
Geosci. Model Dev., 13, 3241–3265,Short summary
Online coupling of meteorology and chemistry models often presents maintenance issues with hard-wired coding. We present WRF-GC, an one-way online coupling of the WRF meteorological model and GEOS-Chem atmospheric chemistry model for regional atmospheric chemistry and air quality modeling. Our coupling structure allows future versions of either parent model to be immediately integrated into WRF-GC. The WRF-GC model was able to well reproduce regional PM2.5 with greater computational efficiency.
Junchen Guo, Shengzhen Zhou, Mingfu Cai, Jun Zhao, Wei Song, Weixiong Zhao, Weiwei Hu, Yele Sun, Yao He, Chengqiang Yang, Xuezhe Xu, Zhisheng Zhang, Peng Cheng, Qi Fan, Jian Hang, Shaojia Fan, Xinming Wang, and Xuemei Wang
Atmos. Chem. Phys., 20, 7595–7615,Short summary
We characterized non-refractory submicron particulate matter (PM1.0) during winter in Guangzhou, south China. Chemical composition and key sources of ambient PM1.0 are revealed, highlighting the significant role of SOA. The relationship with SOA and peroxy radicals indicated gas-phase oxidation contributed predominantly to SOA formation during non-pollution periods, while heterogeneous/multiphase reactions played more important roles in SOA formation during pollution periods.
Jiayue Huang, Lyatt Jaeglé, Qianjie Chen, Becky Alexander, Tomás Sherwen, Mat J. Evans, Nicolas Theys, and Sungyeon Choi
Atmos. Chem. Phys., 20, 7335–7358,Short summary
Large-scale enhancements of tropospheric BrO and the depletion of surface ozone are often observed in the springtime Arctic. Here, we use a chemical transport model to examine the role of sea salt aerosol from blowing snow in explaining these phenomena. We find that our simulation can account for the spatiotemporal variability of satellite observations of BrO. However, the model has difficulty in producing the magnitude of observed ozone depletion events.
Jingyi Li, Haowen Zhang, Qi Ying, Zhijun Wu, Yanli Zhang, Xinming Wang, Xinghua Li, Yele Sun, Min Hu, Yuanhang Zhang, and Jianlin Hu
Atmos. Chem. Phys., 20, 7291–7306,Short summary
Large gaps still exist in modeled and observed secondary organic aerosol (SOA) mass loading and properties. Here we investigated the impacts of water partitioning into organic aerosol and nonideality of the organic–water mixture on SOA over eastern China using a regional 3D model. SOA is increased more significantly in humid and hot environments. Increases in SOA further cause an enhancement of the cooling effects of aerosols. It is crucial to consider the above processes in modeling SOA.
Matthew J. Cooper, Randall V. Martin, Daven K. Henze, and Dylan B. A. Jones
Atmos. Chem. Phys., 20, 7231–7241,Short summary
Comparisons between satellite-retrieved and model-simulated NO2 columns are affected by differences between the model vertical profile and the assumed profile used in the retrieval process. We examine how such differences impact NOx emission estimates from satellite observations. Larger differences between the simulated and assumed profile shape correspond to larger emission errors. This reveals the importance of using consistent profile information when comparing satellite columns to models.
Weiqi Xu, Yao He, Yanmei Qiu, Chun Chen, Conghui Xie, Lu Lei, Zhijie Li, Jiaxing Sun, Junyao Li, Pingqing Fu, Zifa Wang, Douglas R. Worsnop, and Yele Sun
Atmos. Meas. Tech., 13, 3205–3219,Short summary
We characterized mass spectral features of organic aerosol (OA) and water-soluble OA (WSOA) from 21 cooking, crop straw, wood, and coal burning experiments using aerosol mass spectrometers with standard and capture vaporizers, and we demonstrated the applications of source spectral profiles in improving source apportionment of ambient OA at a highly polluted rural site in the North China Plain in winter.
Jing Yang, Wanyu Zhao, Lianfang Wei, Qiang Zhang, Yue Zhao, Wei Hu, Libin Wu, Xiaodong Li, Chandra Mouli Pavuluri, Xiaole Pan, Yele Sun, Zifa Wang, Cong-Qiang Liu, Kimitaka Kawamura, and Pingqing Fu
Atmos. Chem. Phys., 20, 6841–6860,Short summary
Our observations provide novel detailed information on the atmospheric abundances and spatial distributions of dicarboxylic acids, oxoacids, and α-dicarbonyls in marine aerosols collected from the South China Sea to the East Indian Ocean. Our results demonstrate that the continental outflow of both biogenic and anthropogenic precursors followed by photochemical aging is one of the main sources and formation processes of marine organic aerosols over the tropical oceanic regions.
Qiaorong Xie, Sihui Su, Shuang Chen, Yisheng Xu, Dong Cao, Jing Chen, Lujie Ren, Siyao Yue, Wanyu Zhao, Yele Sun, Zifa Wang, Haijie Tong, Hang Su, Yafang Cheng, Kimitaka Kawamura, Guibin Jiang, Cong-Qiang Liu, and Pingqing Fu
Atmos. Chem. Phys., 20, 6803–6820,Short summary
Current knowledge on firework-related organic aerosols is very limited. Here the detailed molecular composition of organics in urban aerosols was characterized using ultrahigh-resolution FT-ICR mass spectrometry. Our findings highlight that firework emission leads to a sharp increase in CHO, CHNO, and CHOS containing high-molecular-weight species, particularly aromatic-like substances, which affect the physicochemical properties such as the light absorption and health effects of urban aerosols.
Shengzhen Zhou, Luolin Wu, Junchen Guo, Weihua Chen, Xuemei Wang, Jun Zhao, Yafang Cheng, Zuzhao Huang, Jinpu Zhang, Yele Sun, Pingqing Fu, Shiguo Jia, Jun Tao, Yanning Chen, and Junxia Kuang
Atmos. Chem. Phys., 20, 6435–6453,Short summary
In this work, measurements of size-segregated aerosols were conducted at three altitudes (ground level, 118 m, and 488 m) on the 610 m high Canton Tower in southern China. Vertical variations of PM and size-segregated chemical compositions were investigated. The results indicated that meteorological parameters and atmospheric aqueous and heterogeneous reactions together led to aerosol formation and haze episodes in the Pearl River Delta region during the measurement periods.
Tao Ma, Hiroshi Furutani, Fengkui Duan, Takashi Kimoto, Jingkun Jiang, Qiang Zhang, Xiaobin Xu, Ying Wang, Jian Gao, Guannan Geng, Meng Li, Shaojie Song, Yongliang Ma, Fei Che, Jie Wang, Lidan Zhu, Tao Huang, Michisato Toyoda, and Kebin He
Atmos. Chem. Phys., 20, 5887–5897,Short summary
The formation mechanisms of organic matter and sulfate in winter haze in the North China Plain remain unclear. This paper presents the identification and quantification of hydroxymethanesulfonate (HMS) in PM2.5 in Beijing winter and elucidates the heterogeneous HMS chemistry in favorable winter haze conditions. We show that the HMS not only contributes a substantial mass of organic matter, but also leads to an overestimation of sulfate in conventional measurements.
Hang Liu, Xiaole Pan, Dantong Liu, Xiaoyong Liu, Xueshun Chen, Yu Tian, Yele Sun, Pingqing Fu, and Zifa Wang
Atmos. Chem. Phys., 20, 5771–5785,Short summary
The bare black carbon (BC) was in a fractal structure. With coating thickness increasing, BC changed from a fractal structure to a core–shell structure. In the ambient atmosphere, plenty of BC particles were not in a perfect core–shell structure. This study brought attention to the combined effects of morphology and coating thickness on the absorption enhancement of BC-containing particles, which is helpful for determining the climatic effects of BC.
Youwen Sun, Cheng Liu, Lin Zhang, Mathias Palm, Justus Notholt, Hao Yin, Corinne Vigouroux, Erik Lutsch, Wei Wang, Changong Shan, Thomas Blumenstock, Tomoo Nagahama, Isamu Morino, Emmanuel Mahieu, Kimberly Strong, Bavo Langerock, Martine De Mazière, Qihou Hu, Huifang Zhang, Christof Petri, and Jianguo Liu
Atmos. Chem. Phys., 20, 5437–5456,Short summary
We present multiyear time series of ground-based Fourier-transform infrared spectroscopy measurements of HCN in densely populated eastern China. The seasonality and interannual variability of tropospheric HCN columns were investigated. The potential sources that drive the observed HCN seasonality and interannual variability were determined using a GEOS-Chem tagged CO simulation, global fire maps, and potential source contribution function values calculated using HYSPLIT back trajectories.
Fanhao Meng, Min Qin, Ke Tang, Jun Duan, Wu Fang, Shuaixi Liang, Kaidi Ye, Pinhua Xie, Yele Sun, Conghui Xie, Chunxiang Ye, Pingqing Fu, Jianguo Liu, and Wenqing Liu
Atmos. Chem. Phys., 20, 5071–5092,Short summary
Nitrous acid (HONO), a major precursor of the OH radical, plays a key role in atmospheric chemistry, but its sources are still debated. The first high-resolution vertical measurements of HONO and NO2 were conducted in Beijing to investigate the nocturnal sources of HONO at different stages of pollution. The ground surface dominated HONO production by heterogeneous conversion of NO2 during clean episodes, but the aerosol production was an important nighttime HONO source during haze episodes.
Havala O. T. Pye, Athanasios Nenes, Becky Alexander, Andrew P. Ault, Mary C. Barth, Simon L. Clegg, Jeffrey L. Collett Jr., Kathleen M. Fahey, Christopher J. Hennigan, Hartmut Herrmann, Maria Kanakidou, James T. Kelly, I-Ting Ku, V. Faye McNeill, Nicole Riemer, Thomas Schaefer, Guoliang Shi, Andreas Tilgner, John T. Walker, Tao Wang, Rodney Weber, Jia Xing, Rahul A. Zaveri, and Andreas Zuend
Atmos. Chem. Phys., 20, 4809–4888,Short summary
Acid rain is recognized for its impacts on human health and ecosystems, and programs to mitigate these effects have had implications for atmospheric acidity. Historical measurements indicate that cloud and fog droplet acidity has changed in recent decades in response to controls on emissions from human activity, while the limited trend data for suspended particles indicate acidity may be relatively constant. This review synthesizes knowledge on the acidity of atmospheric particles and clouds.
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.
Becky Alexander, Tomás Sherwen, Christopher D. Holmes, Jenny A. Fisher, Qianjie Chen, Mat J. Evans, and Prasad Kasibhatla
Atmos. Chem. Phys., 20, 3859–3877,Short summary
Nitrogen oxides are important for the formation of tropospheric oxidants and are removed from the atmosphere mainly through the formation of nitrate. We compare observations of the oxygen isotopes of nitrate with a global model to test our understanding of the chemistry nitrate formation. We use the model to quantify nitrate formation pathways in the atmosphere and identify key uncertainties and their relevance for the oxidation capacity of the atmosphere.
Chenjie Yu, Dantong Liu, Kurtis Broda, Rutambhara Joshi, Jason Olfert, Yele Sun, Pingqing Fu, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 20, 3645–3661,Short summary
This study presents the first atmospheric application of a new morphology-independent measurement for the quantification of the mixing state of rBC-containing particles in urban Beijing as part of the UK–China APHH campaign. An inversion method has been applied for better quantification of rBC mixing state. The mass-resolved rBC mixing state information presented here has implications for detailed models of BC, its optical properties and its atmospheric life cycle.
Shaofeng Xu, Lujie Ren, Yunchao Lang, Shengjie Hou, Hong Ren, Lianfang Wei, Libin Wu, Junjun Deng, Wei Hu, Xiaole Pan, Yele Sun, Zifa Wang, Hang Su, Yafang Cheng, and Pingqing Fu
Atmos. Chem. Phys., 20, 3623–3644,Short summary
Current knowledge on the size distribution of biogenic primary organic aerosols in urban regions with heavy haze pollution is very limited. Here we performed a year-round study focusing on the organic molecular composition of size-segregated aerosol samples collected in urban Beijing during haze and non-haze days to elucidate the seasonal contributions of biomass burning, fungal spores, and plant debris to organic carbon as well as the influences from local emissions and long-range transport.
Archana Dayalu, J. William Munger, Yuxuan Wang, Steven C. Wofsy, Yu Zhao, Thomas Nehrkorn, Chris Nielsen, Michael B. McElroy, and Rachel Chang
Atmos. Chem. Phys., 20, 3569–3588,Short summary
China has pledged to reduce carbon dioxide emissions per unit GDP by 60–65 % relative to 2005 levels, and to peak carbon emissions overall by 2030. Disagreement among available inventories of Chinese emissions makes it difficult for China to track progress toward its goals and evaluate the efficacy of regional control measures. This study uses a unique set of historical atmospheric observations for the key period from 2005 to 2009 to independently evaluate three different CO2 emission estimates.
Yadong Lei, Xu Yue, Hong Liao, Cheng Gong, and Lin Zhang
Geosci. Model Dev., 13, 1137–1153,Short summary
We coupled a dynamic vegetation model YIBs with the chemical transport model GEOS-Chem to develop a new tool for studying interactions between atmospheric chemistry and biosphere. Within this framework, leaf area index and stomatal conductance are predicted for chemical simulations. In turn, surface ozone causes negative impacts to plant growth and the consequent dry deposition. Such interactions are important for air pollution prediction but ignored in most of current chemical models.
Leigh R. Crilley, Ajit Singh, Louisa J. Kramer, Marvin D. Shaw, Mohammed S. Alam, Joshua S. Apte, William J. Bloss, Lea Hildebrandt Ruiz, Pingqing Fu, Weiqi Fu, Shahzad Gani, Michael Gatari, Evgenia Ilyinskaya, Alastair C. Lewis, David Ng'ang'a, Yele Sun, Rachel C. W. Whitty, Siyao Yue, Stuart Young, and Francis D. Pope
Atmos. Meas. Tech., 13, 1181–1193,Short summary
There is considerable interest in using low-cost optical particle counters (OPCs) for particle mass measurements; however, there is no agreed upon method with respect to calibration. Here we exploit a number of datasets globally to demonstrate that particle composition and relative humidity are the key factors affecting measured concentrations from a low-cost OPC, and we present a simple correction methodology that corrects for this influence.
Lu Lei, Conghui Xie, Dawei Wang, Yao He, Qingqing Wang, Wei Zhou, Wei Hu, Pingqing Fu, Yong Chen, Xiaole Pan, Zifa Wang, Douglas R. Worsnop, and Yele Sun
Atmos. Chem. Phys., 20, 2877–2890,Short summary
We characterized aerosol composition and sources near two steel plants in a coastal region in fall and spring seasons. Our results showed substantially different aerosol composition and sources between the two seasons. We observed significant impacts of steel plant emissions on aerosol chemistry nearby, and we found that aerosol particles emitted from the steel plants were dominated by ammonium sulfate/bisulfate; NOx/CO and NOx/SO2 were distinct from those in the absence of industrial plumes.
Tongwen Wu, Fang Zhang, Jie Zhang, Weihua Jie, Yanwu Zhang, Fanghua Wu, Laurent Li, Jinghui Yan, Xiaohong Liu, Xiao Lu, Haiyue Tan, Lin Zhang, Jun Wang, and Aixue Hu
Geosci. Model Dev., 13, 977–1005,Short summary
This paper describes the first version of the Beijing Climate Center (BCC) fully coupled Earth System Model with interactive atmospheric chemistry and aerosols (BCC-ESM1). It is one of the models at the BCC for the Coupled Model Intercomparison Project Phase 6 (CMIP6). The CMIP6 Aerosol Chemistry Model Intercomparison Project (AerChemMIP) experiment using BCC-ESM1 has been finished. The evaluations show an overall good agreement between BCC-ESM1 simulations and observations in the 20th century.
Meng Gao, Zirui Liu, Bo Zheng, Dongsheng Ji, Peter Sherman, Shaojie Song, Jinyuan Xin, Cheng Liu, Yuesi Wang, Qiang Zhang, Jia Xing, Jingkun Jiang, Zifa Wang, Gregory R. Carmichael, and Michael B. McElroy
Atmos. Chem. Phys., 20, 1497–1505,Short summary
We quantified the relative influences of anthropogenic emissions and meteorological conditions on PM2.5 concentrations in Beijing over the winters of 2002–2016. Meteorological conditions over the study period would have led to an increase of haze in Beijing, but the strict emission control measures have suppressed the unfavorable influences of the recent climate.
Viral Shah, Daniel J. Jacob, Ke Li, Rachel F. Silvern, Shixian Zhai, Mengyao Liu, Jintai Lin, and Qiang Zhang
Atmos. Chem. Phys., 20, 1483–1495,Short summary
We analyze 15 years of satellite observations of nitrogen dioxide (NO2) and use an atmospheric chemistry model to understand the seasonal changes and trends in nitrogen oxides (NOx) over China. We show that the seasonal changes in NO2 occur due to changes in the NOx oxidation lifetime. We find that Chinese NOx emissions peaked in 2011 and had decreased by about 25 % by 2018. But the decrease in NO2 in winter was larger, likely because of a simultaneous decrease in the NOx oxidation lifetime.
Xinxin Fan, Jieyao Liu, Fang Zhang, Lu Chen, Don Collins, Weiqi Xu, Xiaoai Jin, Jingye Ren, Yuying Wang, Hao Wu, Shangze Li, Yele Sun, and Zhanqing Li
Atmos. Chem. Phys., 20, 915–929,Short summary
Aerosol effects on visibility and climate are influenced by their hygroscopicity. By contrasting data from two techniques between summer and winter in Beijing, we investigate the effect of aerosol aging, mixing state, and local sources on its hygroscopicity. We revealed that inappropriate use of the density of BC and organics results in large uncertainty in calculating aerosols hygroscopicity. Our results are helpful for parameterization in models.
Xiaoai Jin, Yuying Wang, Zhanqing Li, Fang Zhang, Weiqi Xu, Yele Sun, Xinxin Fan, Guangyu Chen, Hao Wu, Jingye Ren, Qiuyan Wang, and Maureen Cribb
Atmos. Chem. Phys., 20, 901–914,Short summary
In this study the aerosol liquid water content (ALWC) is determined from aerosol hygroscopic growth factor (GF) measurement (ALWCHTDMA) and also simulated by the ISORROPIA II thermodynamic model (ALWCISO). We found that ALWC contributed by organics (ALWCOrg) accounts for 30 % ± 22 % of the total ALWC in winter in Beijing. A case study reveals that ALWCOrg plays an important role in the formation of secondary aerosols through multiphase reactions at the initial stage of a heavy-haze episode.
Ye Kuang, Yao He, Wanyun Xu, Pusheng Zhao, Yafang Cheng, Gang Zhao, Jiangchuan Tao, Nan Ma, Hang Su, Yanyan Zhang, Jiayin Sun, Peng Cheng, Wenda Yang, Shaobin Zhang, Cheng Wu, Yele Sun, and Chunsheng Zhao
Atmos. Chem. Phys., 20, 865–880,Short summary
A new method was developed to calculate hygroscopicity parameter κ of organic aerosols (κOA) based on aerosol light-scattering measurements and bulk aerosol chemical-composition measurements. Derived high-time-resolution κOA varied in a wide range (near 0 to 0.25), and the organic aerosol oxidation degree significantly impacts variations in κOA. Distinct diurnal variation in κOA is found, and its relationship with oxygenated organic aerosol is discussed.
Yanbing Fan, Cong-Qiang Liu, Linjie Li, Lujie Ren, Hong Ren, Zhimin Zhang, Qinkai Li, Shuang Wang, Wei Hu, Junjun Deng, Libin Wu, Shujun Zhong, Yue Zhao, Chandra Mouli Pavuluri, Xiaodong Li, Xiaole Pan, Yele Sun, Zifa Wang, Kimitaka Kawamura, Zongbo Shi, and Pingqing Fu
Atmos. Chem. Phys., 20, 117–137,Short summary
This study provides useful knowledge on the abundance, sources, and formation processes of organic aerosols in the coastal megacity of Tianjin, North China, based on the investigation of the molecular composition, diurnal variation, and winter/summer differences under the influence of land/sea breezes and the Asian summer monsoon.
Danhui Xu, Baozhu Ge, Xueshun Chen, Yele Sun, Nianliang Cheng, Mei Li, Xiaole Pan, Zhiqiang Ma, Yuepeng Pan, and Zifa Wang
Atmos. Chem. Phys., 19, 15569–15581,Short summary
Wet deposition is one of the most important and efficient removal mechanisms in the evolution of the air pollution. Due to the lack of a localized parameterization scheme and some mechanisms being neglected in theoretical estimations and modeling calculations, below-cloud wet scavenging coefficients (BWSC) have large uncertainties. We compare the BWSCs under the same conditions to perform a multi-method evaluation in order to describe their characteristics.
Hang Liu, Xiaole Pan, Yu Wu, Dawei Wang, Yu Tian, Xiaoyong Liu, Lu Lei, Yele Sun, Pingqing Fu, and Zifa Wang
Atmos. Chem. Phys., 19, 14791–14804,Short summary
The relationship among the effective density, rBC's coating thickness, and rBC's morphology was investigated. rBC with larger effective density adopted a more regular shape due to more coating thickness. The effective density distribution of ambient rBC was also measured. From the information of effective density, the ambient rBC mainly adopts an irregular shape, which can cause large uncertainties in the rBC's optical properties.
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.
Weiqi Xu, Conghui Xie, Eleni Karnezi, Qi Zhang, Junfeng Wang, Spyros N. Pandis, Xinlei Ge, Jingwei Zhang, Junling An, Qingqing Wang, Jian Zhao, Wei Du, Yanmei Qiu, Wei Zhou, Yao He, Ying Li, Jie Li, Pingqing Fu, Zifa Wang, Douglas R. Worsnop, and Yele Sun
Atmos. Chem. Phys., 19, 10205–10216,Short summary
We present the first aerosol volatility measurements in Beijing in summer using a thermodenuder coupled with aerosol mass spectrometers. Our results showed that organic aerosol (OA) comprised mainly semi-volatile organic compounds in summer, and the freshly oxidized secondary OA was the most volatile component. We also found quite different volatility distributions in black-carbon-containing primary and secondary OA, ambient OA, ambient secondary OA and the WRF-Chem model.
Michael Hollaway, Oliver Wild, Ting Yang, Yele Sun, Weiqi Xu, Conghui Xie, Lisa Whalley, Eloise Slater, Dwayne Heard, and Dantong Liu
Atmos. Chem. Phys., 19, 9699–9714,Short summary
This study, for the first time, uses combinations of aerosol and lidar data to drive an offline photolysis scheme. Absorbing species are shown to have the greatest impact on photolysis rate constants in the winter and scattering aerosol are shown to dominate responses in the summer. During haze episodes, aerosols are shown to produce a greater impact than cloud cover. The findings demonstrate the potential photochemical impacts of haze pollution in a highly polluted urban environment.
Huiyun Du, Jie Li, Xueshun Chen, Zifa Wang, Yele Sun, Pingqing Fu, Jianjun Li, Jian Gao, and Ying Wei
Atmos. Chem. Phys., 19, 9351–9370,Short summary
Regional transport and heterogeneous reactions play crucial roles in haze formation. Using a chemical transport model, we found that chemical transformation of SO2 along the transport pathway from source regions to Beijing was the major source of sulfate. Heterogeneous chemistry had a stronger effect under high humidity and high pollution levels. Aerosols underwent aging during transport which altered the aerosol size and the degree of aging.
Tabish Umar Ansari, Oliver Wild, Jie Li, Ting Yang, Weiqi Xu, Yele Sun, and Zifa Wang
Atmos. Chem. Phys., 19, 8651–8668,Short summary
We explore the effectiveness of short-term emission controls on haze events in Beijing in October–November 2014 with high-resolution model studies. The model captures observed hourly variation in key pollutants well, but representation of boundary layer processes remains a key constraint. The controls contributed to improved air quality in early November but would not have been sufficient had the meteorology been less favourable. We quantify the much more stringent controls needed in that case.
Xiaole Pan, Hang Liu, Yu Wu, Yu Tian, Yele Sun, Conghui Xie, Xiaoyong Liu, Tianhai Cheng, and Zifa Wang
Atmos. Chem. Phys. Discuss.,
Revised manuscript not accepted
Xiao Lu, Lin Zhang, Youfan Chen, Mi Zhou, Bo Zheng, Ke Li, Yiming Liu, Jintai Lin, Tzung-May Fu, and Qiang Zhang
Atmos. Chem. Phys., 19, 8339–8361,Short summary
Severe and deteriorating surface ozone pollution over major Chinese cities has become an emerging environmental concern in China. This study assesses the source contributions (including anthropogenic, background, and individual natural sources) and meteorological influences of surface ozone over China in 2016–2017 using the GEOS-Chem chemical transport model at high horizontal resolution with the most up-to-date Chinese anthropogenic emission inventory.
Ying Wei, Xueshun Chen, Huansheng Chen, Jie Li, Zifa Wang, Wenyi Yang, Baozhu Ge, Huiyun Du, Jianqi Hao, Wei Wang, Jianjun Li, Yele Sun, and Huili Huang
Atmos. Chem. Phys., 19, 8269–8296,Short summary
This study presents a full description and evaluation of a global–regional nested aerosol and atmospheric chemistry model (IAP-AACM). The simulation for 2014 is evaluated against model datasets and a range of observational datasets. The results show that IAP-AACM is within the range of other models, and reproduces both spatial and seasonal variation of trace gases and aerosols over most areas well. In future, we recommend improving the model's ability to capture high spatial variation of PM2.5.
Zongbo Shi, Tuan Vu, Simone Kotthaus, Roy M. Harrison, Sue Grimmond, Siyao Yue, Tong Zhu, James Lee, Yiqun Han, Matthias Demuzere, Rachel E. Dunmore, Lujie Ren, Di Liu, Yuanlin Wang, Oliver Wild, James Allan, W. Joe Acton, Janet Barlow, Benjamin Barratt, David Beddows, William J. Bloss, Giulia Calzolai, David Carruthers, David C. Carslaw, Queenie Chan, Lia Chatzidiakou, Yang Chen, Leigh Crilley, Hugh Coe, Tie Dai, Ruth Doherty, Fengkui Duan, Pingqing Fu, Baozhu Ge, Maofa Ge, Daobo Guan, Jacqueline F. Hamilton, Kebin He, Mathew Heal, Dwayne Heard, C. Nicholas Hewitt, Michael Hollaway, Min Hu, Dongsheng Ji, Xujiang Jiang, Rod Jones, Markus Kalberer, Frank J. Kelly, Louisa Kramer, Ben Langford, Chun Lin, Alastair C. Lewis, Jie Li, Weijun Li, Huan Liu, Junfeng Liu, Miranda Loh, Keding Lu, Franco Lucarelli, Graham Mann, Gordon McFiggans, Mark R. Miller, Graham Mills, Paul Monk, Eiko Nemitz, Fionna O'Connor, Bin Ouyang, Paul I. Palmer, Carl Percival, Olalekan Popoola, Claire Reeves, Andrew R. Rickard, Longyi Shao, Guangyu Shi, Dominick Spracklen, David Stevenson, Yele Sun, Zhiwei Sun, Shu Tao, Shengrui Tong, Qingqing Wang, Wenhua Wang, Xinming Wang, Xuejun Wang, Zifang Wang, Lianfang Wei, Lisa Whalley, Xuefang Wu, Zhijun Wu, Pinhua Xie, Fumo Yang, Qiang Zhang, Yanli Zhang, Yuanhang Zhang, and Mei Zheng
Atmos. Chem. Phys., 19, 7519–7546,Short summary
APHH-Beijing is a collaborative international research programme to study the sources, processes and health effects of air pollution in Beijing. This introduction to the special issue provides an overview of (i) the APHH-Beijing programme, (ii) the measurement and modelling activities performed as part of it and (iii) the air quality and meteorological conditions during joint intensive field campaigns as a core activity within APHH-Beijing.
Linlin Wang, Junkai Liu, Zhiqiu Gao, Yubin Li, Meng Huang, Sihui Fan, Xiaoye Zhang, Yuanjian Yang, Shiguang Miao, Han Zou, Yele Sun, Yong Chen, and Ting Yang
Atmos. Chem. Phys., 19, 6949–6967,Short summary
Urban boundary layer (UBL) affects the physical and chemical processes of the pollutants, and UBL structure can also be altered by pollutants. This paper presents the interactions between air pollution and the UBL structure by using the field data mainly collected from a 325 m meteorology tower, as well as from a Doppler wind lidar, during a severe heavy pollution event that occurred during 1–4 December 2016 in Beijing.
Dantong Liu, Rutambhara Joshi, Junfeng Wang, Chenjie Yu, James D. Allan, Hugh Coe, Michael J. Flynn, Conghui Xie, James Lee, Freya Squires, Simone Kotthaus, Sue Grimmond, Xinlei Ge, Yele Sun, and Pingqing Fu
Atmos. Chem. Phys., 19, 6749–6769,Short summary
This study provides source attribution and characterization of BC in the Beijing urban environment in both winter and summer. For the first time, the physically and chemically based source apportionments are compared to evaluate the primary source contribution and secondary processing of BC-containing particles. A method is proposed to isolate the BC from the transportation sector and coal combustion sources.
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.
Jialin Li, Meigen Zhang, Guiqian Tang, Yele Sun, Fangkun Wu, and Yongfu Xu
Atmos. Chem. Phys., 19, 6481–6495,Short summary
There are large uncertainties in the sources of secondary organic aerosol (SOA). Simulations of SOA concentrations in China with aqueous SOA formation pathway updated and glyoxal simulation improved reveal that dicarbonyl-derived SOA (AAQ) can explain a significant fraction of the unaccounted SOA sources. The mean AAQ can contribute 60.6 % and 64.5 % to the total concentration of SOA in summer and fall, respectively.
Lei Zhu, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Xuan Wang, Tomás Sherwen, Mat J. Evans, Qianjie Chen, Becky Alexander, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Michael Le Breton, Thomas J. Bannan, and Carl J. Percival
Atmos. Chem. Phys., 19, 6497–6507,Short summary
We quantify the effect of sea salt aerosol on tropospheric bromine chemistry with a new mechanistic description of the halogen chemistry in a global atmospheric chemistry model. For the first time, we are able to reproduce the observed levels of bromide activation from the sea salt aerosol in a manner consistent with bromine oxide radical measured from various platforms. Sea salt aerosol plays a far more complex role in global tropospheric chemistry than previously recognized.
Xiaofei Qin, Xiaohao Wang, Yijie Shi, Guangyuan Yu, Na Zhao, Yanfen Lin, Qingyan Fu, Dongfang Wang, Zhouqing Xie, Congrui Deng, and Kan Huang
Atmos. Chem. Phys., 19, 5923–5940,Short summary
The seasonal pattern of atmospheric mercury species over a regional transport intersection zone in east China indicated impacts from both natural re-emissions and anthropogenic emissions. Quasi-local sources were more important than long-range transport for mercury, opposite from particles. Shipping activities were especially outstanding emissions. Abnormally high GOM was ascribed to the high oxidant levels. The gas–particle partition inhibited the formation of GOM under high particle levels.
Yuqing Ye, Zhouqing Xie, Ming Zhu, and Xinming Wang
Atmos. Chem. Phys. Discuss.,
Preprint withdrawnShort summary
Aerosol samples from the Arctic Ocean and Antarctic atmosphere were analysed by ultrahigh resolution mass spectrometry coupled with negative ion mode electrospray ionization. Hundreds of organic compounds, including organosulfates, nitrooxy-organosulfates, organonitrates and oxygenated hydrocarbons, were detected. Our study presents the first overview of OSs and ONs in the polar regions and promotes the understanding of their characteristics and sources.
Zhenying Xu, Mingxu Liu, Minsi Zhang, Yu Song, Shuxiao Wang, Lin Zhang, Tingting Xu, Tiantian Wang, Caiqing Yan, Tian Zhou, Yele Sun, Yuepeng Pan, Min Hu, Mei Zheng, and Tong Zhu
Atmos. Chem. Phys., 19, 5605–5613,
Xuan Wang, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Lei Zhu, Qianjie Chen, Becky Alexander, Tomás Sherwen, Mathew J. Evans, Ben H. Lee, Jessica D. Haskins, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Gregory L. Huey, and Hong Liao
Atmos. Chem. Phys., 19, 3981–4003,Short summary
Chlorine radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a comprehensive simulation of tropospheric chlorine in a global 3-D model, which includes explicit accounting of chloride mobilization from sea salt aerosol. We find the chlorine chemistry contributes 1.0 % of the global oxidation of methane and decreases global burdens of tropospheric ozone by 7 % and OH by 3 % through the associated bromine radical chemistry.
Junting Zhong, Xiaoye Zhang, Yaqiang Wang, Jizhi Wang, Xiaojing Shen, Hongsheng Zhang, Tijian Wang, Zhouqing Xie, Cheng Liu, Hengde Zhang, Tianliang Zhao, Junying Sun, Shaojia Fan, Zhiqiu Gao, Yubin Li, and Linlin Wang
Atmos. Chem. Phys., 19, 3287–3306,Short summary
In various haze regions in China, including the Guanzhong Plain, the middle and lower reaches of the Yangtze River, the Pearl River Delta, the Sichuan Basin, and the Northeast China Plain, heavy aerosol pollution episodes include inter-/trans-regional transport stages and cumulative stages (CSs). During CSs a two-way feedback mechanism exists between unfavorable meteorological conditions and cumulative aerosol pollution. This two-way feedback is further quantified and its magnitude is compared.
Betty Croft, Randall V. Martin, W. Richard Leaitch, Julia Burkart, Rachel Y.-W. Chang, Douglas B. Collins, Patrick L. Hayes, Anna L. Hodshire, Lin Huang, John K. Kodros, Alexander Moravek, Emma L. Mungall, Jennifer G. Murphy, Sangeeta Sharma, Samantha Tremblay, Gregory R. Wentworth, Megan D. Willis, Jonathan P. D. Abbatt, and Jeffrey R. Pierce
Atmos. Chem. Phys., 19, 2787–2812,Short summary
Summertime Arctic atmospheric aerosols are strongly controlled by processes related to natural regional sources. We use a chemical transport model with size-resolved aerosol microphysics to interpret measurements made during summertime 2016 in the Canadian Arctic Archipelago. Our results explore the processes that control summertime aerosol size distributions and support a climate-relevant role for Arctic marine secondary organic aerosol formed from precursor vapors with Arctic marine sources.
Robyn N. C. Latimer and Randall V. Martin
Atmos. Chem. Phys., 19, 2635–2653,Short summary
Long-term aerosol measurements from the IMPROVE network were used to investigate the simulation of mass scattering efficiency in the GEOS-Chem chemical transport model. The simulation of mass scattering efficiency was developed to better represent observations by refining the representation of aerosol size and hygroscopicity. Simulated average mass scattering efficiency over North America increased by 16 %, with larger increases in northern regions and reductions in the southwest.
Kate R. Smith, Peter M. Edwards, Peter D. Ivatt, James D. Lee, Freya Squires, Chengliang Dai, Richard E. Peltier, Mat J. Evans, Yele Sun, and Alastair C. Lewis
Atmos. Meas. Tech., 12, 1325–1336,Short summary
Clusters of low-cost, low-power atmospheric gas sensors were built into a sensor instrument to monitor NO2 and O3 in Beijing, alongside reference instruments, aiming to improve the reliability of sensor measurements. Clustering identical sensors and using the median sensor signal was used to minimize drift over short and medium timescales. Three different machine learning techniques were used for all the sensor data in an attempt to correct for cross-interferences, which worked to some degree.
Jonathan P. D. Abbatt, W. Richard Leaitch, Amir A. Aliabadi, Allan K. Bertram, Jean-Pierre Blanchet, Aude Boivin-Rioux, Heiko Bozem, Julia Burkart, Rachel Y. W. Chang, Joannie Charette, Jai P. Chaubey, Robert J. Christensen, Ana Cirisan, Douglas B. Collins, Betty Croft, Joelle Dionne, Greg J. Evans, Christopher G. Fletcher, Martí Galí, Roghayeh Ghahremaninezhad, Eric Girard, Wanmin Gong, Michel Gosselin, Margaux Gourdal, Sarah J. Hanna, Hakase Hayashida, Andreas B. Herber, Sareh Hesaraki, Peter Hoor, Lin Huang, Rachel Hussherr, Victoria E. Irish, Setigui A. Keita, John K. Kodros, Franziska Köllner, Felicia Kolonjari, Daniel Kunkel, Luis A. Ladino, Kathy Law, Maurice Levasseur, Quentin Libois, John Liggio, Martine Lizotte, Katrina M. Macdonald, Rashed Mahmood, Randall V. Martin, Ryan H. Mason, Lisa A. Miller, Alexander Moravek, Eric Mortenson, Emma L. Mungall, Jennifer G. Murphy, Maryam Namazi, Ann-Lise Norman, Norman T. O'Neill, Jeffrey R. Pierce, Lynn M. Russell, Johannes Schneider, Hannes Schulz, Sangeeta Sharma, Meng Si, Ralf M. Staebler, Nadja S. Steiner, Jennie L. Thomas, Knut von Salzen, Jeremy J. B. Wentzell, Megan D. Willis, Gregory R. Wentworth, Jun-Wei Xu, and Jacqueline D. Yakobi-Hancock
Atmos. Chem. Phys., 19, 2527–2560,Short summary
The Arctic is experiencing considerable environmental change with climate warming, illustrated by the dramatic decrease in sea-ice extent. It is important to understand both the natural and perturbed Arctic systems to gain a better understanding of how they will change in the future. This paper summarizes new insights into the relationships between Arctic aerosol particles and climate, as learned over the past five or so years by a large Canadian research consortium, NETCARE.
Shaojie Song, Meng Gao, Weiqi Xu, Yele Sun, Douglas R. Worsnop, John T. Jayne, Yuzhong Zhang, Lei Zhu, Mei Li, Zhen Zhou, Chunlei Cheng, Yibing Lv, Ying Wang, Wei Peng, Xiaobin Xu, Nan Lin, Yuxuan Wang, Shuxiao Wang, J. William Munger, Daniel J. Jacob, and Michael B. McElroy
Atmos. Chem. Phys., 19, 1357–1371,Short summary
Chemistry responsible for sulfate production in northern China winter haze remains mysterious. We propose a potentially key pathway through the reaction of formaldehyde and sulfur dioxide that has not been accounted for in previous studies. The special atmospheric conditions favor the formation and existence of their complex, hydroxymethanesulfonate (HMS).
Jun Chen, Zhanqing Li, Min Lv, Yuying Wang, Wei Wang, Yingjie Zhang, Haofei Wang, Xing Yan, Yele Sun, and Maureen Cribb
Atmos. Chem. Phys., 19, 1327–1342,Short summary
The hygroscopic growth function of aerosol particles is derived from Raman lidar, whose dependence on aerosol chemical composition is investigated using data from an aerosol chemical speciation monitor (ACSM) and a hygroscopic tandem differential mobility analyzer (H-TDMA) deployed in China. Two distinct cases were chosen with marked differences in their hygroscopic growth, which was fitted by the Kasten model. The differences were attributed to different amounts of chemical species.
Junfeng Wang, Dantong Liu, Xinlei Ge, Yangzhou Wu, Fuzhen Shen, Mindong Chen, Jian Zhao, Conghui Xie, Qingqing Wang, Weiqi Xu, Jie Zhang, Jianlin Hu, James Allan, Rutambhara Joshi, Pingqing Fu, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 447–458,Short summary
This work is part of the UK-China APHH campaign. We used a laser-only Aerodyne soot particle aerosol mass spectrometer, for the first time, to investigate the concentrations, size distributions and chemical compositions for those ambient submicron aerosol particles only with black carbon as cores. Our findings are valuable to understand the BC properties and processes in the densely populated megacities.
Qiang Huang, Jiubin Chen, Weilin Huang, John R. Reinfelder, Pingqing Fu, Shengliu Yuan, Zhongwei Wang, Wei Yuan, Hongming Cai, Hong Ren, Yele Sun, and Li He
Atmos. Chem. Phys., 19, 315–325,Short summary
Although the specific reactions and mechanisms in fine aerosols could not be explicitly determined from this field study, our results provide isotopic evidence that local daily photochemical reduction of divalent Hg is of critical importance to the fate of PM2.5-Hg in urban atmospheres and that, in addition to variation in sources, photochemical reduction appears to be an important process that affects both the particle mass-specific abundance and isotopic composition of PM2.5-Hg.
Conghui Xie, Weiqi Xu, Junfeng Wang, Qingqing Wang, Dantong Liu, Guiqian Tang, Ping Chen, Wei Du, Jian Zhao, Yingjie Zhang, Wei Zhou, Tingting Han, Qingyun Bian, Jie Li, Pingqing Fu, Zifa Wang, Xinlei Ge, James Allan, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 165–179,Short summary
We present the first simultaneous real-time online measurements of aerosol optical properties at ground level and at 260 m on a meteorological tower in urban Beijing in winter. The vertical similarities and differences in scattering and absorption coefficients were characterized. The increases in MAC of BC were mainly associated with the coating materials on rBC. Coal combustion was the dominant source contribution of brown carbon followed by biomass burning and SOA in winter in Beijing.
Mingxu Liu, Xin Huang, Yu Song, Tingting Xu, Shuxiao Wang, Zhijun Wu, Min Hu, Lin Zhang, Qiang Zhang, Yuepeng Pan, Xuejun Liu, and Tong Zhu
Atmos. Chem. Phys., 18, 17933–17943,
Lu Shen, Daniel J. Jacob, Loretta J. Mickley, Yuxuan Wang, and Qiang Zhang
Atmos. Chem. Phys., 18, 17489–17496,
Eloise A. Marais, Daniel J. Jacob, Sungyeon Choi, Joanna Joiner, Maria Belmonte-Rivas, Ronald C. Cohen, Steffen Beirle, Lee T. Murray, Luke D. Schiferl, Viral Shah, and Lyatt Jaeglé
Atmos. Chem. Phys., 18, 17017–17027,Short summary
We intercompare two new products of global upper tropospheric nitrogen dioxide (NO2) retrieved from the Ozone Monitoring Instrument (OMI). We evaluate these products with aircraft observations from NASA DC8 aircraft campaigns and interpret the useful information these products can provide about nitrogen oxides (NOx) in the global upper troposphere using the GEOS-Chem chemical transport model.
Jeffrey A. Geddes, Randall V. Martin, Eric J. Bucsela, Chris A. McLinden, and Daniel J. M. Cunningham
Atmos. Meas. Tech., 11, 6271–6287,Short summary
This paper describes an approach for separating the stratospheric and tropospheric contributions in geostationary observations of nitrogen dioxide from the upcoming TEMPO instrument. We find minimal impact of the limited field of observation compared to previous low-Earth-observing systems with global coverage. We find that continued development of low-Earth-orbit retrievals will benefit geostationary data by providing important context outside the field of regard.
Yangyang Zhang, Aohan Tang, Dandan Wang, Qingqing Wang, Katie Benedict, Lin Zhang, Duanyang Liu, Yi Li, Jeffrey L. Collett Jr., Yele Sun, and Xuejun Liu
Atmos. Chem. Phys., 18, 16385–16398,Short summary
Our study is the first to continually monitor the vertical concentration profile of NH3 in urban Beijing. Weekly concentrations averaged 13.3 ± 4.8 μg m−3. The highest NH3 concentrations were always observed between 32 and 63 m, decreasing toward the surface and toward higher altitudes. Our results demonstrate a NH3 rich atmosphere in urban Beijing, from the ground to at least 320 m. Regional transport from the south (intensive agricultural regions) contributed high NH3 concentrations in Beijing.
Jiayue Huang, Lyatt Jaeglé, and Viral Shah
Atmos. Chem. Phys., 18, 16253–16269,Short summary
The contribution of blowing snow and frost flower as sources of sea salt aerosols (SSA) over polar regions remains uncertain, despite its potentially important role in polar climate and chemistry. Using chemical transport models and satellite observations, we find that blowing snow emissions are the dominant source of SSA over sea ice during the cold season. We infer a monthly snow salinity on first-year sea ice that decreases from fall–spring, minimizing the model discrepancy to within 10 %.
Archana Dayalu, J. William Munger, Steven C. Wofsy, Yuxuan Wang, Thomas Nehrkorn, Yu Zhao, Michael B. McElroy, Chris P. Nielsen, and Kristina Luus
Biogeosciences, 15, 6713–6729,Short summary
Accounting for the vegetation signal is critical for comprehensive CO2 budget assessment in China. We model and evaluate hourly vegetation carbon dioxide (CO2) exchange (mass per unit area per unit time) in northern China from 2005 to 2009. The model is driven by satellite and meteorological data, is linked to ground-level ecosystem observations, and is applicable to other time periods. We find vegetation uptake of CO2 in summer is comparable to emissions from fossil fuels in northern China.
Shaojie Song, Hélène Angot, Noelle E. Selin, Hubert Gallée, Francesca Sprovieri, Nicola Pirrone, Detlev Helmig, Joël Savarino, Olivier Magand, and Aurélien Dommergue
Atmos. Chem. Phys., 18, 15825–15840,Short summary
Mercury is a trace metal with adverse health effects on human and wildlife. Its unique property makes it undergo long-range transport, and even remote Antarctica receives significant inputs. This paper presents the first model that aims to understand mercury behavior over the Antarctic Plateau. We find that mercury is quickly cycled between snow and air in the sunlit period, likely driven by bromine chemistry, and that several uncertain processes contribute to its behavior in the dark period.
Hansen Cao, Tzung-May Fu, Lin Zhang, Daven K. Henze, Christopher Chan Miller, Christophe Lerot, Gonzalo González Abad, Isabelle De Smedt, Qiang Zhang, Michel van Roozendael, François Hendrick, Kelly Chance, Jie Li, Junyu Zheng, and Yuanhong Zhao
Atmos. Chem. Phys., 18, 15017–15046,Short summary
Our top-down estimates for annual total Chinese NMVOC emissions was 30.7 to 49.5 Tg y−1, including 16.4 to 23.6 Tg y−1 from anthropogenic sources, 12.2 to 22.8 Tg y−1 from biogenic sources, and 2.08 to 3.13 Tg y−1 from biomass burning. Our four inversions consistently showed that the emissions of Chinese anthropogenic NMVOC precursors of glyoxal were larger than the a priori estimates. The glyoxal and formaldehyde constraints helped distinguish the NMVOC species from different sources.
Yingjie Zhang, Wei Du, Yuying Wang, Qingqing Wang, Haofei Wang, Haitao Zheng, Fang Zhang, Hongrong Shi, Yuxuan Bian, Yongxiang Han, Pingqing Fu, Francesco Canonaco, André S. H. Prévôt, Tong Zhu, Pucai Wang, Zhanqing Li, and Yele Sun
Atmos. Chem. Phys., 18, 14637–14651,Short summary
We have a comprehensive characterization of aerosol chemistry and particle growth events at a downwind site of a highly polluted city in the North China Plain. Aerosol particles at the urban downwind site were highly aged and mainly from secondary formation. New particle growth events were also frequently observed on both clean and polluted days. While both sulfate and SOA played important roles in particle growth during clean periods, SOA was more important than sulfate during polluted events.
Lei Liu, Jian Zhang, Liang Xu, Qi Yuan, Dao Huang, Jianmin Chen, Zongbo Shi, Yele Sun, Pingqing Fu, Zifa Wang, Daizhou Zhang, and Weijun Li
Atmos. Chem. Phys., 18, 14681–14693,Short summary
Using transmission electron microscopy, we studied individual cloud droplet residual and interstitial particles collected in cloud events at Mt. Tai in the polluted North China region. We found that individual cloud droplets were an extremely complicated mixture containing abundant refractory soot (i.e., black carbon), fly ash, and metals. The complicated cloud droplets have not been reported in clean continental or marine air before.
Pengzhen He, Zhouqing Xie, Xiyuan Chi, Xiawei Yu, Shidong Fan, Hui Kang, Cheng Liu, and Haicong Zhan
Atmos. Chem. Phys., 18, 14465–14476,Short summary
We present the first observations of the oxygen-17 excess of atmospheric nitrate (Δ17O(NO−3)) collected in Beijing haze to reveal the relative importance of different nitrate formation pathways. We found that nocturnal pathways (N2O5 + H2O/Cl– and NO3 + HC) dominated nitrate production during polluted days (PM2.5 ≥ 75 μg m–3), with a mean possible fraction of 56–97 %.
Mingjie Kang, Pingqing Fu, Kimitaka Kawamura, Fan Yang, Hongliang Zhang, Zhengchen Zang, Hong Ren, Lujie Ren, Ye Zhao, Yele Sun, and Zifa Wang
Atmos. Chem. Phys., 18, 13947–13967,Short summary
Molecular characterization and spatial distribution of biogenic primary organic aerosol (POA) and secondary organic aerosol (SOA) in the marine atmosphere are not well known. Here, we analysed the organic molecular composition of marine aerosols collected during a marine cruise in the East China Sea during May–June 2014. Our results suggest that the Asian continent can be a natural emitter of biogenic POA and SOA, which can be transported to the downwind marine atmosphere.
Qianjie Chen, Tomás Sherwen, Mathew Evans, and Becky Alexander
Atmos. Chem. Phys., 18, 13617–13637,Short summary
Uncertainty in the natural tropospheric sulfur cycle represents the largest source of uncertainty in radiative forcing estimates of sulfate aerosol. This study investigates the natural sulfur cycle in the marine troposphere using the GEOS-Chem model. We found that BrO is important for DMS oxidation and multiphase chemistry is important for MSA production and loss, which have implications for the yield of SO2 and MSA from DMS oxidation and the radiative effect of DMS-derived sulfate aerosol.
Yuying Wang, Zhanqing Li, Yingjie Zhang, Wei Du, Fang Zhang, Haobo Tan, Hanbing Xu, Tianyi Fan, Xiaoai Jin, Xinxin Fan, Zipeng Dong, Qiuyan Wang, and Yele Sun
Atmos. Chem. Phys., 18, 11739–11752,Short summary
Very different aerosol hygroscopicities and mixing states were found at these sites in the North China Plain. The PDF for 40–200 nm particles showed the particles were highly aged and internally mixed at Xingtai because of high pollution and strong photochemical reactions. A good proxy for the chemical comical composition (kappa = 0.31) in calculating CCN concentration was found. Importantly, our study investigated the influence of industrial emissions on the aerosol properties.
Wei Zhou, Jian Zhao, Bin Ouyang, Archit Mehra, Weiqi Xu, Yuying Wang, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Qi Chen, Conghui Xie, Qingqing Wang, Junfeng Wang, Wei Du, Yingjie Zhang, Xinlei Ge, Penglin Ye, James D. Lee, Pingqing Fu, Zifa Wang, Douglas Worsnop, Roderic Jones, Carl J. Percival, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 18, 11581–11597,Short summary
We present measurements of gas-phase N2O5 and ClNO2 by ToF-CIMS during summer in urban Beijing as part of the APHH campaign. High reactivity of N2O5 indicative of active nocturnal chemistry was observed. The lifetime of N2O5 as a function of aerosol surface area and relative humidity was characterized, and N2O5 uptake coefficients were estimated. We also found that the N2O5 loss in this study is mainly attributed to its indirect loss via reactions of NO3 with VOCs and NO.
Prasad Kasibhatla, Tomás Sherwen, Mathew J. Evans, Lucy J. Carpenter, Chris Reed, Becky Alexander, Qianjie Chen, Melissa P. Sulprizio, James D. Lee, Katie A. Read, William Bloss, Leigh R. Crilley, William C. Keene, Alexander A. P. Pszenny, and Alma Hodzic
Atmos. Chem. Phys., 18, 11185–11203,Short summary
Recent measurements of NOx and HONO suggest that photolysis of particulate nitrate in sea-salt aerosols is important in terms of marine boundary layer oxidant chemistry. We present the first global-scale assessment of the significance of this new chemical pathway for NOx, O3, and OH in the marine boundary layer. We also present a preliminary assessment of the potential impact of photolysis of particulate nitrate associated with other aerosol types on continental boundary layer chemistry.
Wen Xu, Lei Liu, Miaomiao Cheng, Yuanhong Zhao, Lin Zhang, Yuepeng Pan, Xiuming Zhang, Baojing Gu, Yi Li, Xiuying Zhang, Jianlin Shen, Li Lu, Xiaosheng Luo, Yu Zhao, Zhaozhong Feng, Jeffrey L. Collett Jr., Fusuo Zhang, and Xuejun Liu
Atmos. Chem. Phys., 18, 10931–10954,Short summary
Our main results demonstrate that atmospheric Nr pollution in eastern China is more serious in the northern region than in the southern region. Any effects of current emission controls are not yet apparent in Nr pollution. NH3 emissions from fertilizer use were the largest contributor (36 %) to total inorganic Nr deposition. Our results provide useful information for policy-makers that mitigation of NH3 emissions should be a priority to tackle serious N deposition.
Yele Sun, Weiqi Xu, Qi Zhang, Qi Jiang, Francesco Canonaco, André S. H. Prévôt, Pingqing Fu, Jie Li, John Jayne, Douglas R. Worsnop, and Zifa Wang
Atmos. Chem. Phys., 18, 8469–8489,Short summary
We present a 2–year analysis of organic aerosol (OA) from highly time–resolved measurements by an aerosol chemical speciation monitor in the megacity of Beijing. The sources of OA were analyzed with the advanced factor analysis of a multilinear engine (ME-2). Our results showed very different seasonal patterns, relative humidity and temperature dependence, and sources regions among different OA factors. The sources and processes of OA factors, and their roles in haze pollution are elucidated.
Melanie S. Hammer, Randall V. Martin, Chi Li, Omar Torres, Max Manning, and Brian L. Boys
Atmos. Chem. Phys., 18, 8097–8112,Short summary
We apply a simulation of the Ultraviolet Aerosol Index (UVAI), a method of detecting aerosol absorption from satellite observations, to interpret UVAI values observed by the Ozone Monitoring Instrument (OMI) from 2005 to 2015 to understand global trends in aerosol composition. We find that global trends in the UVAI are largely explained by trends in absorption by mineral dust, absorption by brown carbon, and scattering by secondary inorganic aerosol.
Chandra Venkataraman, Michael Brauer, Kushal Tibrewal, Pankaj Sadavarte, Qiao Ma, Aaron Cohen, Sreelekha Chaliyakunnel, Joseph Frostad, Zbigniew Klimont, Randall V. Martin, Dylan B. Millet, Sajeev Philip, Katherine Walker, and Shuxiao Wang
Atmos. Chem. Phys., 18, 8017–8039,
Jie Zhang, Sara Lance, Jeffrey M. Freedman, Yele Sun, Brian A. Crandall, Xiuli Wei, and James J. Schwab
Atmos. Chem. Phys. Discuss.,
Preprint retractedShort summary
The impact of fireworks (FW) events on air quality was studied using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and collocated instruments during the Independence Day (July 4) holiday. The Independence Day FW events resulted in significant increases in both organic and inorganic (potassium, sulfate, chloride) chemical components, and the contribution from different aerosol sources was discussed.
Shaojie Song, Meng Gao, Weiqi Xu, Jingyuan Shao, Guoliang Shi, Shuxiao Wang, Yuxuan Wang, Yele Sun, and Michael B. McElroy
Atmos. Chem. Phys., 18, 7423–7438,Short summary
Severe haze events occur frequently over northern China, especially in winter. Acidity plays a critical role in the formation of secondary PM2.5 and its toxicity. Using field measurements of gases and particles to critically evaluate two thermodynamic models routinely employed to determine particle acidity, we found that China's winter haze particles are generally within a moderately acidic range (pH 4–5) and not highly acidic (0) or neutral (7) as has been previously reported in the literature.
Matthew J. Cooper, Randall V. Martin, Alexei I. Lyapustin, and Chris A. McLinden
Atmos. Meas. Tech., 11, 2983–2994,Short summary
To accurately infer air pollutant concentrations from satellite observations, we must first know the reflectivity of the Earth’s surface. Using a model, we show that satellite observations are better able to observe NO2 near the surface if snow is present. However, knowing when snow is present is difficult due to its variability. We test seven existing snow cover data sets to assess their ability to inform future satellite observations and find that the IMS data set is best suited for this task.
Jingye Ren, Fang Zhang, Yuying Wang, Don Collins, Xinxin Fan, Xiaoai Jin, Weiqi Xu, Yele Sun, Maureen Cribb, and Zhanqing Li
Atmos. Chem. Phys., 18, 6907–6921,
Qianqian Hong, Cheng Liu, Ka Lok Chan, Qihou Hu, Zhouqing Xie, Haoran Liu, Fuqi Si, and Jianguo Liu
Atmos. Chem. Phys., 18, 5931–5951,Short summary
We presented ship-based MAX-DOAS measurements of tropospheric trace gases' distribution along the eastern part of the Yangtze River during winter 2015. Tropospheric VCDs of NO2, SO2, and HCHO were retrieved from MAX-DOAS measurement spectra. Enhanced tropospheric NO2 and SO2 VCDs were detected over downwind areas of industrial zones over the Yangtze River. Our results indicate that different pollution control strategies should be applied in different provinces.
Pengzhen He, Becky Alexander, Lei Geng, Xiyuan Chi, Shidong Fan, Haicong Zhan, Hui Kang, Guangjie Zheng, Yafang Cheng, Hang Su, Cheng Liu, and Zhouqing Xie
Atmos. Chem. Phys., 18, 5515–5528,Short summary
We use observations of the oxygen isotopic composition of sulfate aerosol as a fingerprint to quantify various sulfate formation mechanisms during pollution events in Beijing, China. We found that heterogeneous reactions on aerosols dominated sulfate production in general; however, in-cloud reactions would dominate haze sulfate production when cloud liquid water content was high. The findings also suggest the heterogeneity of aerosol acidity should be parameterized in models.
Jennifer Kaiser, Daniel J. Jacob, Lei Zhu, Katherine R. Travis, Jenny A. Fisher, Gonzalo González Abad, Lin Zhang, Xuesong Zhang, Alan Fried, John D. Crounse, Jason M. St. Clair, and Armin Wisthaler
Atmos. Chem. Phys., 18, 5483–5497,Short summary
Isoprene emissions from vegetation have a large effect on atmospheric chemistry and air quality. Here we use the adjoint of GEOS-Chem in an inversion of OMI formaldehyde observations to produce top-down estimates of isoprene emissions in the southeast US during the summer of 2013. We find that MEGAN v2.1 is biased high on average by 40 %. Our downward correction of isoprene emissions leads to a small reduction in modeled surface O3 and decreases the contribution of isoprene to organic aerosol.
Wei Zhou, Qingqing Wang, Xiujuan Zhao, Weiqi Xu, Chen Chen, Wei Du, Jian Zhao, Francesco Canonaco, André S. H. Prévôt, Pingqing Fu, Zifa Wang, Douglas R. Worsnop, and Yele Sun
Atmos. Chem. Phys., 18, 3951–3968,Short summary
We present a 3-month analysis of submicron aerosols that were measured at 260 m on a meteorological tower in Beijing, China. The sources of organic aerosol (OA) were analyzed by using a multi-linear engine (ME-2). Our results showed significant changes in both primary and secondary OA composition from the non-heating season to the heating season. We also observed a considerable contribution (10–13%) of cooking OA at 260 m and very different OA composition between ground level and 260 m.
Meng Li, Zbigniew Klimont, Qiang Zhang, Randall V. Martin, Bo Zheng, Chris Heyes, Janusz Cofala, Yuxuan Zhang, and Kebin He
Atmos. Chem. Phys., 18, 3433–3456,Short summary
In this paper, we conducted a comprehensive evaluation of two widely used anthropogenic emission inventories over China, ECLIPSE and MIX, to explore the potential sources of uncertainties and find clues to improving emission inventories. We found that SO2 emission estimates are consistent between the two inventories (with 1 % differences), while NOx emissions in ECLIPSE's estimates are 16 % lower than those in MIX. Discrepancies at the sector and provincial levels are much higher.
Xiao Lu, Lin Zhang, Xiong Liu, Meng Gao, Yuanhong Zhao, and Jingyuan Shao
Atmos. Chem. Phys., 18, 3101–3118,Short summary
Deteriorating tropospheric ozone pollution over India may not only affect local human health and vegetation but also perturb global ozone distribution. This study analyzes the processes controlling lower tropospheric ozone over India using OMI satellite observations (2006–2014) and model simulations (1990–2010). We show that the South Asian monsoon largely controls the seasonal cycle and interannual variability of Indian lower tropospheric ozone via changes in ozone production and transport.
Wanyu Zhao, Kimitaka Kawamura, Siyao Yue, Lianfang Wei, Hong Ren, Yu Yan, Mingjie Kang, Linjie Li, Lujie Ren, Senchao Lai, Jie Li, Yele Sun, Zifa Wang, and Pingqing Fu
Atmos. Chem. Phys., 18, 2749–2767,Short summary
In this paper, we investigate the seasonal trends in concentrations and compound-specific stable carbon isotope ratios of low molecular weight dicarboxylic acids (C2–C12) and related compounds in fine aerosols (PM2.5) in Beijing. Our study demonstrates that, in addition to the production via photo-oxidation, high abundances of diacids and related compounds in Beijing are largely associated with anthropogenic primary emissions such as biomass burning, fossil fuel combustion and plastic burning.
Qingqing Wang, Yele Sun, Weiqi Xu, Wei Du, Libo Zhou, Guiqian Tang, Chen Chen, Xueling Cheng, Xiujuan Zhao, Dongsheng Ji, Tingting Han, Zhe Wang, Jie Li, and Zifa Wang
Atmos. Chem. Phys., 18, 2495–2509,Short summary
We conducted the first real-time continuous vertical measurements of particle extinction, NO2, and BC from ground level to 260 m during two severe winter haze episodes in urban Beijing, China. Our results show very complex and dynamic vertical profiles that interact closely with boundary layer and meteorological conditions. Further analysis demonstrate that vertical convection, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles.
Lin Zhang, Youfan Chen, Yuanhong Zhao, Daven K. Henze, Liye Zhu, Yu Song, Fabien Paulot, Xuejun Liu, Yuepeng Pan, Yi Lin, and Binxiang Huang
Atmos. Chem. Phys., 18, 339–355,Short summary
Substantial differences exist in current estimates of agricultural ammonia emissions in China, hindering understanding of their environmental consequences. This study applies both bottom-up and top-down methods to better quantify agricultural ammonia sources in China using observations from satellite and surface networks interpreted by a chemical transport model. Our estimate of annual Chinese anthropogenic ammonia emission is 11.7 tg (teragram) for 2008 with a strong seasonality peak in summer.
Zheng Fang, Wei Deng, Yanli Zhang, Xiang Ding, Mingjin Tang, Tengyu Liu, Qihou Hu, Ming Zhu, Zhaoyi Wang, Weiqiang Yang, Zhonghui Huang, Wei Song, Xinhui Bi, Jianmin Chen, Yele Sun, Christian George, and Xinming Wang
Atmos. Chem. Phys., 17, 14821–14839,Short summary
Primary emissions and aging of open straw burning plumes were characterized in ambient dilution conditions in a chamber. Rich in alkenes, the plumes have high O3 formation potential. The emissions of specific particulate and gaseous compounds were less when the straws were fully burned. Organic aerosol (OA) mass increased by a factor of 2–8 with 3–9 h photo-oxidation, yet > 70 % of the mass cannot be explained by the known precursors. OA gained more O- and N-containing compounds during aging.
Yunjiang Zhang, Lili Tang, Philip L. Croteau, Olivier Favez, Yele Sun, Manjula R. Canagaratna, Zhuang Wang, Florian Couvidat, Alexandre Albinet, Hongliang Zhang, Jean Sciare, André S. H. Prévôt, John T. Jayne, and Douglas R. Worsnop
Atmos. Chem. Phys., 17, 14501–14517,Short summary
We conducted the first field measurements of non-refractory fine aerosols (NR-PM2.5) in a megacity of eastern China using a PM2.5-ACSM along with a PM1-ACSM measurement. Inter-comparisons demonstrated that the NR-PM2.5 components can be characterized. Substantial mass fractions of aerosol species were observed in the size range of 1–2.5 μm, with sulfate and SOA being the two largest contributors. The impacts of aerosol water driven by secondary inorganic aerosols on SOA formation were explored.
Chengzhi Xing, Cheng Liu, Shanshan Wang, Ka Lok Chan, Yang Gao, Xin Huang, Wenjing Su, Chengxin Zhang, Yunsheng Dong, Guangqiang Fan, Tianshu Zhang, Zhenyi Chen, Qihou Hu, Hang Su, Zhouqing Xie, and Jianguo Liu
Atmos. Chem. Phys., 17, 14275–14289,Short summary
Vertical profiles of the aerosol extinction coefficient and NO2 and HCHO concentrations were retrieved from MAX-DOAS measurement, while vertical distribution of O3 was obtained using ozone lidar. The measured O3 vertical distribution indicates that the ozone production not only occurs at surface level but also at higher altitudes (about 1.1 km), which are not directly related to horizontal and vertical transportation but are mainly influenced by the abundance of VOCs in the lower troposphere.
Yuxuan Wang, Yuanyu Xie, Wenhao Dong, Yi Ming, Jun Wang, and Lu Shen
Atmos. Chem. Phys., 17, 12827–12843,Short summary
Besides the well-known large impact on agriculture and water resources, drought is associated with significant adverse effects on air quality. Drought-induced degradation of air quality is largely due to natural processes, offsetting the effort of anthropogenic emission reduction during the past decades. Such adverse impacts should be included in modeling processes under current and future climate for mitigation policy.
Yue Zhao, Jeremy K. Chan, Felipe D. Lopez-Hilfiker, Megan A. McKeown, Emma L. D'Ambro, Jay G. Slowik, Jeffrey A. Riffell, and Joel A. Thornton
Atmos. Meas. Tech., 10, 3609–3625,Short summary
We present a novel atmospheric pressure electrospray chemical ionization (ESCI) source that can generate intense and stable currents of several specific reagent ions using a range of salt solutions prepared in methanol. We couple the ESCI source to a high-resolution time-of-flight mass spectrometer (HRToF-MS) and assess instrument performance through calibrations using different gas standards and measurements of organic mixtures formed by ozonolysis of α-pinene.
Hongyan Zhao, Xin Li, Qiang Zhang, Xujia Jiang, Jintai Lin, Glen P. Peters, Meng Li, Guannan Geng, Bo Zheng, Hong Huo, Lin Zhang, Haikun Wang, Steven J. Davis, and Kebin He
Atmos. Chem. Phys., 17, 10367–10381,Short summary
Effective and efficient control of air pollution relies upon an understanding of the pollution sources. We conduct an interdisciplinary study and find that 33 % of China’s PM2.5-related premature mortality in 2010 were caused by production emission in other regions; 56 % of the mortality was related to consumption in other regions. Multilateral and multi-stage cooperation under a regional sustainable development framework is in urgent need to mitigate air pollution and related health impacts.
Jeffrey A. Geddes and Randall V. Martin
Atmos. Chem. Phys., 17, 10071–10091,Short summary
We use observations of nitrogen dioxide columns from multiple satellite instruments with the help of a chemical transport model to constrain the global deposition of reactive nitrogen oxides (NOy) over the last 2 decades. NOy deposition decreased by up to 60 % in eastern North America, doubled in regions of East Asia, and declined by 20 % in parts of Western Europe. We also find changes in the export of NOy via atmospheric transport, with direct impacts on countries downwind of source regions.
Yuanhong Zhao, Lin Zhang, Amos P. K. Tai, Youfan Chen, and Yuepeng Pan
Atmos. Chem. Phys., 17, 9781–9796,Short summary
Human activities have substantially enhanced atmospheric deposition of reactive nitrogen, inducing complex environmental consequences. This study presents a first quantitative investigation of how anthropogenic nitrogen deposition could impact surface ozone air quality through surface–atmosphere exchange processes. We find important surface ozone changes driven by nitrogen deposition, which can be comparable with those due to historical climate and land use changes.
Viral Shah and Lyatt Jaeglé
Atmos. Chem. Phys., 17, 8999–9017,Short summary
We use a model of mercury chemistry and transport in the atmosphere, along with ground- and aircraft-based mercury observations, to learn that oxidized mercury chemically produced in the free troposphere descends in the subtropical anticyclones and makes up much of the mercury depositing to the Earth's surface. Our findings imply that mercury chemistry in the free troposphere and transport in the subtropics are important links between global emissions and surface deposition of mercury.
Johannes Bieser, Franz Slemr, Jesse Ambrose, Carl Brenninkmeijer, Steve Brooks, Ashu Dastoor, Francesco DeSimone, Ralf Ebinghaus, Christian N. Gencarelli, Beate Geyer, Lynne E. Gratz, Ian M. Hedgecock, Daniel Jaffe, Paul Kelley, Che-Jen Lin, Lyatt Jaegle, Volker Matthias, Andrei Ryjkov, Noelle E. Selin, Shaojie Song, Oleg Travnikov, Andreas Weigelt, Winston Luke, Xinrong Ren, Andreas Zahn, Xin Yang, Yun Zhu, and Nicola Pirrone
Atmos. Chem. Phys., 17, 6925–6955,Short summary
We conducted a multi model study to investigate our ability to reproduce the vertical distribution of mercury in the atmosphere. For this, we used observational data from over 40 aircraft flights in EU and US. We compared observations to the results of seven chemistry transport models and found that the models are able to reproduce vertical gradients of total and elemental Hg. Finally, we found that different chemical reactions seem responsible for the oxidation of Hg depending on altitude.
Wei Du, Jian Zhao, Yuying Wang, Yingjie Zhang, Qingqing Wang, Weiqi Xu, Chen Chen, Tingting Han, Fang Zhang, Zhanqing Li, Pingqing Fu, Jie Li, Zifa Wang, and Yele Sun
Atmos. Chem. Phys., 17, 6797–6811,Short summary
We conducted the first simultaneous measurements of size-resolved particle number concentrations at ground level and 260 m in urban Beijing. The vertical differences strongly depend on particle sizes, with accumulation-mode particles being highly correlated at the two heights. We further demonstrated that regional emission controls have a dominant impact on accumulation-mode particles, while the influences on Aitken particles were much smaller due to the enhanced NPF events.
Ting Yang, Zifa Wang, Wei Zhang, Alex Gbaguidi, Nobuo Sugimoto, Xiquan Wang, Ichiro Matsui, and Yele Sun
Atmos. Chem. Phys., 17, 6215–6225,Short summary
Predicting air pollution events over megacities requires, notably, continuous and accurate determination of the boundary layer height (BLH). Based on gravity wave theory, a new approach (CRGM) is developed to overcome existing algorithms' weakness in order to accurately reproduce the fluctuations of the BLH under various atmospheric pollution conditions from lidar observation. Comprehensive evaluation highlights strong effectiveness of this new method.
Oleg Travnikov, Hélène Angot, Paulo Artaxo, Mariantonia Bencardino, Johannes Bieser, Francesco D'Amore, Ashu Dastoor, Francesco De Simone, María del Carmen Diéguez, Aurélien Dommergue, Ralf Ebinghaus, Xin Bin Feng, Christian N. Gencarelli, Ian M. Hedgecock, Olivier Magand, Lynwill Martin, Volker Matthias, Nikolay Mashyanov, Nicola Pirrone, Ramesh Ramachandran, Katie Alana Read, Andrei Ryjkov, Noelle E. Selin, Fabrizio Sena, Shaojie Song, Francesca Sprovieri, Dennis Wip, Ingvar Wängberg, and Xin Yang
Atmos. Chem. Phys., 17, 5271–5295,Short summary
The study provides a complex analysis of processes governing Hg fate in the atmosphere involving both measurement data and simulation results of chemical transport models. Evaluation of the model simulations and numerical experiments against observations allows explaining spatial and temporal variations of Hg concentration in the near-surface atmospheric layer and shows possibility of multiple pathways of Hg oxidation occurring concurrently in various parts of the atmosphere.
Yuying Wang, Fang Zhang, Zhanqing Li, Haobo Tan, Hanbing Xu, Jingye Ren, Jian Zhao, Wei Du, and Yele Sun
Atmos. Chem. Phys., 17, 5239–5251,Short summary
A series of strict emission control measures were implemented in Beijing and the surrounding seven provinces to ensure good air quality during the 2015 China Victory Day parade, rendering a unique opportunity to investigate anthropogenic impact of aerosol properties. Submicron aerosol hygroscopicity and volatility were measured during and after the control period. By comparison we found aerosol particles became more hydrophobic and volatile due to the emission control measures.
Yue Zhao, Michelle C. Fairhurst, Lisa M. Wingen, Véronique Perraud, Michael J. Ezell, and Barbara J. Finlayson-Pitts
Atmos. Meas. Tech., 10, 1373–1386,Short summary
Two model systems are studied: dicarboxylic acid particles with gaseous amines and α-cedrene ozonolysis particles. Measurements by direct analysis in real-time mass spectrometry and high-resolution time-of-flight aerosol mass spectrometry show that the reaction of the amines with the acid particles is restricted to the surface layer, with an odd–even alternating pattern. Furthermore, in the α-cedrene study, DART-MS is able to differentiate isomers based on their volatility.
Guannan Geng, Qiang Zhang, Randall V. Martin, Jintai Lin, Hong Huo, Bo Zheng, Siwen Wang, and Kebin He
Atmos. Chem. Phys., 17, 4131–4145,Short summary
We investigated the impact of spatial proxies on the representation of gridded emissions by comparing six gridded NOx emission datasets over China developed from the same magnitude of emissions and different spatial proxies. GEOS-Chem-modeled NO2 columns from the six gridded emissions are compared with satellite-based columns from OMI. Results show that differences between modeled and satellite-based NO2 columns are sensitive to the spatial proxies used in the gridded emission inventories.
Jian Zhao, Wei Du, Yingjie Zhang, Qingqing Wang, Chen Chen, Weiqi Xu, Tingting Han, Yuying Wang, Pingqing Fu, Zifa Wang, Zhanqing Li, and Yele Sun
Atmos. Chem. Phys., 17, 3215–3232,Short summary
We conducted aerosol particle composition measurements at ground level and 260 m with two aerosol mass spectrometers in Beijing during the 2015 China Victory Day parade. Our results showed a stronger impact of emission controls on inorganic aerosol than OA. A larger decrease in more oxidized SOA than the less oxidized one during the control period was also observed. Our results indicate that emission controls and the changes in meteorological conditions have affected SOA formation mechanisms.
Shurui Chen, Liang Xu, Yinxiao Zhang, Bing Chen, Xinfeng Wang, Xiaoye Zhang, Mei Zheng, Jianmin Chen, Wenxing Wang, Yele Sun, Pingqing Fu, Zifa Wang, and Weijun Li
Atmos. Chem. Phys., 17, 1259–1270,Short summary
Many studies have focused on the unusually severe hazes instead of the more frequent light and moderate hazes (22–63 %) in winter in the North China Plain (NCP). The morphology, mixing state, and size of organic aerosols in the L & M hazes were characterized. We conclude that the direct emissions from residential coal stoves without any pollution controls in rural and urban outskirts contribute large amounts of primary OM particles to the regional L & M hazes in winter in the NCP.
Wen Xu, Wei Song, Yangyang Zhang, Xuejun Liu, Lin Zhang, Yuanhong Zhao, Duanyang Liu, Aohan Tang, Daowei Yang, Dandan Wang, Zhang Wen, Yuepeng Pan, David Fowler, Jeffrey L. Collett Jr., Jan Willem Erisman, Keith Goulding, Yi Li, and Fusuo Zhang
Atmos. Chem. Phys., 17, 31–46,Short summary
This paper evaluates the effectiveness of emission control measures implemented in Beijing during the Parade Blue period by integrating our own results, official-released data and modeling data. We demonstrate that emission control measures make a major contribution to air quality improvement in Beijing and surrounding regions. We conclude a joint local and regional control of secondary aerosol precursors to be key to curbing air pollution in Beijing.
Yuxuan Wang, Beixi Jia, Sing-Chun Wang, Mark Estes, Lu Shen, and Yuanyu Xie
Atmos. Chem. Phys., 16, 15265–15276,Short summary
This paper provides empirical evidence that the year-to-year variability of summertime ozone over Houston is linked to the Bermuda High (BH) large-scale circulation patterns. It identifies two BH indices that can explain up to 70 % of the interannual variability of summertime ozone in Houston and illustrates the mechanism underlying the BH and ozone linkage. Such a mechanism is tested for applicability to other coastal urban regions along the US Gulf Coast.
Xiao Lu, Lin Zhang, Xu Yue, Jiachen Zhang, Daniel A. Jaffe, Andreas Stohl, Yuanhong Zhao, and Jingyuan Shao
Atmos. Chem. Phys., 16, 14687–14702,Short summary
Increasing wildfire activities in the mountainous western US may present a challenge for the region to attain a recently revised ozone air quality standard in summer. We quantify the wildfire influence on the ozone variability, trends, and number of high ozone days over this region in summers 1989–2010 using a Lagrangian dispersion model and statistical regression models.
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.
Maria Zatko, Joseph Erbland, Joel Savarino, Lei Geng, Lauren Easley, Andrew Schauer, Timothy Bates, Patricia K. Quinn, Bonnie Light, David Morison, Hans D. Osthoff, Seth Lyman, William Neff, Bin Yuan, and Becky Alexander
Atmos. Chem. Phys., 16, 13837–13851,Short summary
This manuscript presents chemical and optical observations collected in the air and snow during UBWOS2014 in eastern Utah. These observations are used to calculate fluxes of reactive nitrogen associated with snow nitrate photolysis. Snow-sourced reactive nitrogen fluxes are compared to reactive nitrogen emission inventories to find that snow-sourced reactive nitrogen is a minor contributor to the reactive nitrogen budget, and thus wintertime ground-level ozone formation, in the Uintah Basin.
Qianqian Hong, Zhouqing Xie, Cheng Liu, Feiyue Wang, Pinhua Xie, Hui Kang, Jin Xu, Jiancheng Wang, Fengcheng Wu, Pengzhen He, Fusheng Mou, Shidong Fan, Yunsheng Dong, Haicong Zhan, Xiawei Yu, Xiyuan Chi, and Jianguo Liu
Atmos. Chem. Phys., 16, 13807–13821,Short summary
It is known that rapid industrialization in developing countries has led to an increase in air pollution. Here we firstly report the speciated atmospheric mercury during haze days based upon 1-year synchronous observations in an inland city in China. The findings provide direct evidence to understand the biogeochemical cycles of atmospheric mercury related to air pollution and an opportunity to evaluate the potential health risks of atmospheric mercury.
Qianjie Chen, Lei Geng, Johan A. Schmidt, Zhouqing Xie, Hui Kang, Jordi Dachs, Jihong Cole-Dai, Andrew J. Schauer, Madeline G. Camp, and Becky Alexander
Atmos. Chem. Phys., 16, 11433–11450,Short summary
The formation mechanisms of sulfate in the marine boundary layer are not well understood, which could result in large uncertainties in aerosol radiative forcing. We measure the oxygen isotopic composition (Δ17O) of sulfate collected in the MBL and analyze with a global transport model. Our results suggest that 33–50 % of MBL sulfate is formed via oxidation of S(IV) by hypohalous acids HOBr / HOCl in the aqueous phase, and the daily-mean HOBr/HOCl concentrations are on the order of 0.01–0.1 ppt.
Xiawei Yu, Zhibin Wang, Minghui Zhang, Uwe Kuhn, Zhouqing Xie, Yafang Cheng, Ulrich Pöschl, and Hang Su
Atmos. Chem. Phys., 16, 11337–11348,
Hélène Angot, Ashu Dastoor, Francesco De Simone, Katarina Gårdfeldt, Christian N. Gencarelli, Ian M. Hedgecock, Sarka Langer, Olivier Magand, Michelle N. Mastromonaco, Claus Nordstrøm, Katrine A. Pfaffhuber, Nicola Pirrone, Andrei Ryjkov, Noelle E. Selin, Henrik Skov, Shaojie Song, Francesca Sprovieri, Alexandra Steffen, Kenjiro Toyota, Oleg Travnikov, Xin Yang, and Aurélien Dommergue
Atmos. Chem. Phys., 16, 10735–10763,Short summary
This is a synthesis of the atmospheric mercury (Hg) monitoring data available in recent years (2011–2015) in the Arctic and in Antarctica along with a comparison of these observations with numerical simulations using four cutting-edge global models. Based on this comparison, we discuss whether the processes that affect atmospheric Hg seasonality and interannual variability are appropriately represented in the models, and identify remaining research gaps.
Graydon Snider, Crystal L. Weagle, Kalaivani K. Murdymootoo, Amanda Ring, Yvonne Ritchie, Emily Stone, Ainsley Walsh, Clement Akoshile, Nguyen Xuan Anh, Rajasekhar Balasubramanian, Jeff Brook, Fatimah D. Qonitan, Jinlu Dong, Derek Griffith, Kebin He, Brent N. Holben, Ralph Kahn, Nofel Lagrosas, Puji Lestari, Zongwei Ma, Amit Misra, Leslie K. Norford, Eduardo J. Quel, Abdus Salam, Bret Schichtel, Lior Segev, Sachchida Tripathi, Chien Wang, Chao Yu, Qiang Zhang, Yuxuan Zhang, Michael Brauer, Aaron Cohen, Mark D. Gibson, Yang Liu, J. Vanderlei Martins, Yinon Rudich, and Randall V. Martin
Atmos. Chem. Phys., 16, 9629–9653,Short summary
We examine the chemical composition of fine particulate matter (PM2.5) collected on filters at traditionally undersampled, globally dispersed urban locations. Several PM2.5 chemical components (e.g. ammonium sulfate, ammonium nitrate, and black carbon) vary by more than an order of magnitude between sites while aerosol hygroscopicity varies by a factor of 2. Enhanced anthropogenic dust fractions in large urban areas are apparent from high Zn : Al ratios.
Junfeng Wang, Xinlei Ge, Yanfang Chen, Yafei Shen, Qi Zhang, Yele Sun, Jianzhong Xu, Shun Ge, Huan Yu, and Mindong Chen
Atmos. Chem. Phys., 16, 9109–9127,Short summary
Highly time- and chemically resolved submicron aerosol properties were characterized online for the first time during springtime in Nanjing by using the Aerodyne SP-AMS. Both chemical and size information of black carbon together with other aerosol species were simultaneously determined. An in-depth analysis of the data elucidates the sources and evolution processes of the fine aerosols in the YRD region. Our findings are valuable for air quality remediation in the densely populated regions.
Yele Sun, Wei Du, Pingqing Fu, Qingqing Wang, Jie Li, Xinlei Ge, Qi Zhang, Chunmao Zhu, Lujie Ren, Weiqi Xu, Jian Zhao, Tingting Han, Douglas R. Worsnop, and Zifa Wang
Atmos. Chem. Phys., 16, 8309–8329,Short summary
We have a comprehensive characterization of the sources, variations and processes of submicron aerosols in Beijing in winter using HR-AMS and GC/MS measurements. The primary sources including traffic, cooking, biomass burning and coal combustion emissions, and secondary components were separated and quantified with PMF. Our results elucidated the important roles of primary emissions, particularly coal combustion, and aqueous-phase processing in the formation of severe air pollution in winter.
Emma L. Mungall, Betty Croft, Martine Lizotte, Jennie L. Thomas, Jennifer G. Murphy, Maurice Levasseur, Randall V. Martin, Jeremy J. B. Wentzell, John Liggio, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 6665–6680,Short summary
Previous work has suggested that marine emissions of dimethyl sulfide (DMS) could impact the Arctic climate through interactions with clouds. We made the first high-time-resolution measurements of summertime atmospheric DMS in the Canadian Arctic, and performed source sensitivity simulations. We found that regional marine sources dominated, but do not appear to be sufficient to explain our observations. Understanding DMS sources in the Arctic is necessary to model future climate in the region.
Sajeev Philip, Randall V. Martin, and Christoph A. Keller
Geosci. Model Dev., 9, 1683–1695,Short summary
We assessed the sensitivity of simulation accuracy to the duration of chemical and transport operators in a chemistry-transport model. Longer continuous transport operator duration increases concentrations of emitted species. Chemical operator duration twice that of the transport operator duration offers more simulation accuracy per unit computation. The simulation error from coarser spatial resolution generally exceeds that from longer operator duration.
Fang Zhang, Zhanqing Li, Yanan Li, Yele Sun, Zhenzhu Wang, Ping Li, Li Sun, Pucai Wang, Maureen Cribb, Chuanfeng Zhao, Tianyi Fan, Xin Yang, and Qingqing Wang
Atmos. Chem. Phys., 16, 5413–5425,
Betty Croft, Randall V. Martin, W. Richard Leaitch, Peter Tunved, Thomas J. Breider, Stephen D. D'Andrea, and Jeffrey R. Pierce
Atmos. Chem. Phys., 16, 3665–3682,Short summary
Measurements at high-Arctic sites show a strong annual cycle in atmospheric particle number and size. Previous studies identified poor scientific understanding related to global model representation of Arctic particle number and size, limiting ability to simulate this environment. Here we evaluate state-of-science ability to simulate Arctic particles using GEOS-Chem-TOMAS model, documenting key roles and interconnections of particle formation, cloud-related processes and remaining uncertainties.
N. I. Kristiansen, A. Stohl, D. J. L. Olivié, B. Croft, O. A. Søvde, H. Klein, T. Christoudias, D. Kunkel, S. J. Leadbetter, Y. H. Lee, K. Zhang, K. Tsigaridis, T. Bergman, N. Evangeliou, H. Wang, P.-L. Ma, R. C. Easter, P. J. Rasch, X. Liu, G. Pitari, G. Di Genova, S. Y. Zhao, Y. Balkanski, S. E. Bauer, G. S. Faluvegi, H. Kokkola, R. V. Martin, J. R. Pierce, M. Schulz, D. Shindell, H. Tost, and H. Zhang
Atmos. Chem. Phys., 16, 3525–3561,Short summary
Processes affecting aerosol removal from the atmosphere are not fully understood. In this study we investigate to what extent atmospheric transport models can reproduce observed loss of aerosols. We compare measurements of radioactive isotopes, that attached to ambient sulfate aerosols during the 2011 Fukushima nuclear accident, to 19 models using identical emissions. Results indicate aerosol removal that is too fast in most models, and apply to aerosols that have undergone long-range transport.
Yue Zhao, Lisa M. Wingen, Véronique Perraud, and Barbara J. Finlayson-Pitts
Atmos. Chem. Phys., 16, 3245–3264,Short summary
A significant fraction of airborne particles, which have significant impacts on human health, visibility, and climate, are formed from the oxidation of gaseous precursors to generate low-volatility products. We show here that a sesquiterpene, α-cedrene, efficiently forms high-viscosity semisolid particles with complex composition via mechanisms that involve the highly reactive Criegee intermediate and that high molecular weight products play an important role in new particle formation.
Maria Zatko, Lei Geng, Becky Alexander, Eric Sofen, and Katarina Klein
Atmos. Chem. Phys., 16, 2819–2842,Short summary
We have incorporated an idealized snowpack with a nitrate photolysis parameterization into a global chemical transport model (GEOS-Chem) to examine the implications of snow nitrate photolysis for boundary layer chemistry, the recycling and redistribution of reactive nitrogen, and the preservation of ice-core nitrate in ice cores across Antarctica and Greenland. We also examine the sensitivity of these processes to meteorological parameters and chemical, optical, and physical snow properties.
Chi Li, Randall V. Martin, Brian L. Boys, Aaron van Donkelaar, and Sacha Ruzzante
Atmos. Chem. Phys., 16, 2435–2457,Short summary
We comprehensively screen and process global hourly visibility data to construct a more reliable monthly inverse visibility (1/Vis) data set, and to infer trends in atmospheric haze. Consistency is found for the inferred 1/Vis seasonality and trends with other collocated in situ aerosol measurements over the US and Europe. Trends of 1/Vis over 1945–1996 for the eastern US, and over 1973–2013 for Europe and eastern Asia are significantly associated with the variation of SO2 emission.
Wei Deng, Qihou Hu, Tengyu Liu, Xinming Wang, Yanli Zhang, Xiang Ding, Yele Sun, Xinhui Bi, Jianzhen Yu, Weiqiang Yang, Xinyu Huang, Zhou Zhang, Zhonghui Huang, Quanfu He, A. Mellouki, and Christian George
Atmos. Chem. Phys. Discuss.,
Revised manuscript not accepted
Jeffrey A. Geddes, Colette L. Heald, Sam J. Silva, and Randall V. Martin
Atmos. Chem. Phys., 16, 2323–2340,Short summary
Land use and land cover changes driven by anthropogenic activities or natural causes (e.g., forestry management, agriculture, wildfires) can impact climate and air quality in many complex ways. Using a state-of-the-art chemistry model, we investigate how tree mortality in the US due to insect infestation and disease outbreak may impact atmospheric composition. We find that the surface concentrations of ozone and aerosol can be altered due to changing background emissions and loss processes.
Gregory R. Wentworth, Jennifer G. Murphy, Betty Croft, Randall V. Martin, Jeffrey R. Pierce, Jean-Sébastien Côté, Isabelle Courchesne, Jean-Éric Tremblay, Jonathan Gagnon, Jennie L. Thomas, Sangeeta Sharma, Desiree Toom-Sauntry, Alina Chivulescu, Maurice Levasseur, and Jonathan P. D. Abbatt
Atmos. Chem. Phys., 16, 1937–1953,Short summary
Air near the surface in the summertime Arctic is extremely clean and typically has very low concentrations of both gases and particles. However, atmospheric measurements taken throughout the Canadian Arctic in the summer of 2014 revealed higher-than-expected amounts of gaseous ammonia. It is likely the majority of this ammonia is coming from migratory seabird colonies throughout the Arctic. Seabird guano (dung) releases ammonia which could impact climate and sensitive Arctic ecosystems.
V. Shah, L. Jaeglé, L. E. Gratz, J. L. Ambrose, D. A. Jaffe, N. E. Selin, S. Song, T. L. Campos, F. M. Flocke, M. Reeves, D. Stechman, M. Stell, J. Festa, J. Stutz, A. J. Weinheimer, D. J. Knapp, D. D. Montzka, G. S. Tyndall, E. C. Apel, R. S. Hornbrook, A. J. Hills, D. D. Riemer, N. J. Blake, C. A. Cantrell, and R. L. Mauldin III
Atmos. Chem. Phys., 16, 1511–1530,Short summary
We present airborne observations of mercury over the southeastern USA during summer. Higher concentrations of oxidized mercury were observed in clean, dry air masses descending in the subtropical anti-cyclones. We used an atmospheric model to simulate the chemistry and transport of mercury. We found reasonable agreement with the observations when the modeled oxidation of elemental mercury was increased, suggesting fast cycling between elemental and oxidized mercury.
T. Liu, X. Wang, Q. Hu, W. Deng, Y. Zhang, X. Ding, X. Fu, F. Bernard, Z. Zhang, S. Lü, Q. He, X. Bi, J. Chen, Y. Sun, J. Yu, P. Peng, G. Sheng, and J. Fu
Atmos. Chem. Phys., 16, 675–689,Short summary
The formation of SOA and sulfate aerosols from the photooxidation of gasoline vehicle exhaust (GVE) when mixing with SO2 was investigated in a smog chamber. We found that the presence of GVE enhanced the conversion of SO2 to sulfate predominantly through reactions with stabilized Criegee intermediates. On the other hand, the elevated particle acidity enhanced the SOA production from GVE. This study indicated that SO2 and GVE could enhance each other in forming secondary aerosols.
S. Walter, A. Kock, T. Steinhoff, B. Fiedler, P. Fietzek, J. Kaiser, M. Krol, M. E. Popa, Q. Chen, T. Tanhua, and T. Röckmann
Biogeosciences, 13, 323–340,Short summary
Oceans are a source of H2, an indirect greenhouse gas. Measurements constraining the temporal and spatial patterns of oceanic H2 emissions are sparse and although H2 is assumed to be produced mainly biologically, direct evidence for biogenic marine production was lacking. By analyzing the H2 isotopic composition (δD) we were able to constrain the global H2 budget in more detail, verify biogenic production and point to additional sources. We also showed that current models are reasonably working.
W. Q. Xu, Y. L. Sun, C. Chen, W. Du, T. T. Han, Q. Q. Wang, P. Q. Fu, Z. F. Wang, X. J. Zhao, L. B. Zhou, D. S. Ji, P. C. Wang, and D. R. Worsnop
Atmos. Chem. Phys., 15, 13681–13698,Short summary
We have investigated the response of aerosol composition, size distributions, and oxidation properties to emission controls during the 2014 Asia- Pacific E