Articles | Volume 20, issue 9
https://doi.org/10.5194/acp-20-5293-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-20-5293-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 May 2020
Research article |
| 15 May 2020
| 15 May 2020
O2 : CO2 exchange ratio for net turbulent flux observed in an urban area of Tokyo, Japan, and its application to an evaluation of anthropogenic CO2 emissions
National Institute of Advanced Industrial Science and Technology
(AIST), Tsukuba 305-8569, Japan
Hirofumi Sugawara
Department of Earth and Ocean Sciences, National Defense Academy of
Japan, Yokosuka 239-8686, Japan
Yukio Terao
National Institute for Environmental Studies, Tsukuba 305-8506, Japan
Naoki Kaneyasu
National Institute of Advanced Industrial Science and Technology
(AIST), Tsukuba 305-8569, Japan
Nobuyuki Aoki
National Institute of Advanced Industrial Science and Technology
(AIST), Tsukuba 305-8569, Japan
Kazuhiro Tsuboi
Meteorological Research Institute, Tsukuba 305-0052, Japan
Hiroaki Kondo
National Institute of Advanced Industrial Science and Technology
(AIST), Tsukuba 305-8569, Japan
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Stratospheric air samples have been collected using balloon-borne cryogenic samplers over Japan and analyzed for the isotopic and elemental ratios of noble gases. We report the results of the first study on the vertical changes of Kr, Xe, and Ne in the stratosphere. The observed results suggest that not only gravitational separation but also kinetic fractionation occurred in the stratosphere. The kinetic fractionations would be an additional tool to diagnose stratospheric transport processes.
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In this study, offsets of CO2 values due to thermal diffusion effect were observed in the outflowing gas from cylinders finding that the CO2 mole fraction in a cylinder deviate by this effect as the pressure dropped. This result suggests that the deviation in the CO2 value in the cylinder is caused not only by the adsorption and desorption effects but also by the thermal diffusion fractionation effect.
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We have been collected stratospheric air samples since 1985 over Japan and analyzed them for δ13CO2. δ13CO2 has decreased through time in the mid-stratosphere with an average rate of change of −0.026 ± 0.001 ‰ yr−1. It has become clear that the oxidation of methane and gravitational separation are important for stratospheric δ13CO2 variations. We newly defined ‘stratospheric potential δ13C’ as a quasi-conservative parameter and demonstrated that it can be used as an air age tracer.
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The 18O/16O ratio of atmospheric oxygen, δatm(18O), is higher than that of ocean water due to isotopic effects during biospheric activities. This is known as the Dole–Morita effect, and its millennial-scale variations are recorded in ice cores. However, small variations of δatm(18O) in the present day have never been detected so far. This paper presents the first observations of diurnal, seasonal, and secular variations in δatm(18O) and applies them to evaluate oxygen, carbon, and water cycles.
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This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Stratospheric air samples have been collected using balloon-borne cryogenic samplers over Japan and analyzed for the isotopic and elemental ratios of noble gases. We report the results of the first study on the vertical changes of Kr, Xe, and Ne in the stratosphere. The observed results suggest that not only gravitational separation but also kinetic fractionation occurred in the stratosphere. The kinetic fractionations would be an additional tool to diagnose stratospheric transport processes.
Nobuyuki Aoki and Shigeyuki Ishidoya
EGUsphere, https://doi.org/10.5194/egusphere-2025-2618, https://doi.org/10.5194/egusphere-2025-2618, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary
Short summary
In this study, offsets of CO2 values due to thermal diffusion effect were observed in the outflowing gas from cylinders finding that the CO2 mole fraction in a cylinder deviate by this effect as the pressure dropped. This result suggests that the deviation in the CO2 value in the cylinder is caused not only by the adsorption and desorption effects but also by the thermal diffusion fractionation effect.
Satoshi Sugawara, Shinji Morimoto, Shigeyuki Ishidoya, Taku Umezawa, Shuji Aoki, Takakiyo Nakazawa, Sakae Toyoda, Kentaro Ishijima, Daisuke Goto, and Hideyuki Honda
EGUsphere, https://doi.org/10.5194/egusphere-2025-1003, https://doi.org/10.5194/egusphere-2025-1003, 2025
Short summary
Short summary
We have been collected stratospheric air samples since 1985 over Japan and analyzed them for δ13CO2. δ13CO2 has decreased through time in the mid-stratosphere with an average rate of change of −0.026 ± 0.001 ‰ yr−1. It has become clear that the oxidation of methane and gravitational separation are important for stratospheric δ13CO2 variations. We newly defined ‘stratospheric potential δ13C’ as a quasi-conservative parameter and demonstrated that it can be used as an air age tracer.
Shigeyuki Ishidoya, Satoshi Sugawara, and Atsushi Okazaki
Atmos. Chem. Phys., 25, 1965–1987, https://doi.org/10.5194/acp-25-1965-2025, https://doi.org/10.5194/acp-25-1965-2025, 2025
Short summary
Short summary
The 18O/16O ratio of atmospheric oxygen, δatm(18O), is higher than that of ocean water due to isotopic effects during biospheric activities. This is known as the Dole–Morita effect, and its millennial-scale variations are recorded in ice cores. However, small variations of δatm(18O) in the present day have never been detected so far. This paper presents the first observations of diurnal, seasonal, and secular variations in δatm(18O) and applies them to evaluate oxygen, carbon, and water cycles.
Masahito Ueyama, Yuta Takao, Hiromi Yazawa, Makiko Tanaka, Hironori Yabuki, Tomo’omi Kumagai, Hiroki Iwata, Md. Abdul Awal, Mingyuan Du, Yoshinobu Harazono, Yoshiaki Hata, Takashi Hirano, Tsutom Hiura, Reiko Ide, Sachinobu Ishida, Mamoru Ishikawa, Kenzo Kitamura, Yuji Kominami, Shujiro Komiya, Ayumi Kotani, Yuta Inoue, Takashi Machimura, Kazuho Matsumoto, Yojiro Matsuura, Yasuko Mizoguchi, Shohei Murayama, Hirohiko Nagano, Taro Nakai, Tatsuro Nakaji, Ko Nakaya, Shinjiro Ohkubo, Takeshi Ohta, Keisuke Ono, Taku M. Saitoh, Ayaka Sakabe, Takanori Shimizu, Seiji Shimoda, Michiaki Sugita, Kentaro Takagi, Yoshiyuki Takahashi, Naoya Takamura, Satoru Takanashi, Takahiro Takimoto, Yukio Yasuda, Qinxue Wang, Jun Asanuma, Hideo Hasegawa, Tetsuya Hiyama, Yoshihiro Iijima, Shigeyuki Ishidoya, Masayuki Itoh, Tomomichi Kato, Hiroaki Kondo, Yoshiko Kosugi, Tomonori Kume, Takahisa Maeda, Trofim Maximov, Ryo Moriwaki, Hiroyuki Muraoka, Roman Petrov, Jun Suzuki, Shingo Taniguchi, and Kazuhito Ichii
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-615, https://doi.org/10.5194/essd-2024-615, 2025
Revised manuscript accepted for ESSD
Short summary
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The JapanFlux2024 dataset, created through collaboration across Japan and East Asia, includes eddy covariance data from 79 sites spanning 652 site-years (1990–2023). This comprehensive dataset offers valuable insights into energy, water, and CO2 fluxes, supporting research on land-atmosphere interactions and process models. Compatible with FLUXNET, it fosters global collaboration and advances research in environmental science and regional climate dynamics.
Masahito Ueyama, Taku Umezawa, Yukio Terao, Mark Lunt, and James Lawrence France
EGUsphere, https://doi.org/10.5194/egusphere-2024-3926, https://doi.org/10.5194/egusphere-2024-3926, 2025
Short summary
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Methane (CH4) emissions were measured in Megacity Osaka, Japan, using mobile and eddy covariance methods. The CH4 emissions were much higher than those reported in local inventories, with natural gas contributing up to 74 % of the emissions. Several CH4 sources not accounted for in current inventories were identified. These results emphasize the need for more comprehensive emissions tracking in urban areas to enhance climate change mitigation efforts.
Vishnu Thilakan, Dhanyalekshmi Pillai, Jithin Sukumaran, Christoph Gerbig, Haseeb Hakkim, Vinayak Sinha, Yukio Terao, Manish Naja, and Monish Vijay Deshpande
Atmos. Chem. Phys., 24, 5315–5335, https://doi.org/10.5194/acp-24-5315-2024, https://doi.org/10.5194/acp-24-5315-2024, 2024
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This study investigates the usability of CO2 mixing ratio observations over India to infer regional carbon sources and sinks. We demonstrate that a high-resolution modelling system can represent the observed CO2 variations reasonably well by improving the transport and flux variations at a fine scale. Future carbon data assimilation systems can thus benefit from these recently available CO2 observations when fine-scale variations are adequately represented in the models.
Shigeyuki Ishidoya, Kazuhiro Tsuboi, Hiroaki Kondo, Kentaro Ishijima, Nobuyuki Aoki, Hidekazu Matsueda, and Kazuyuki Saito
Atmos. Chem. Phys., 24, 1059–1077, https://doi.org/10.5194/acp-24-1059-2024, https://doi.org/10.5194/acp-24-1059-2024, 2024
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A method evaluating techniques for carbon neutrality, such as carbon capture and storage (CCS), is important. This study presents a method to evaluate CO2 emissions from a cement plant based on atmospheric O2 and CO2 measurements. The method will also be useful for evaluating CO2 capture from flue gas at CCS plants, since the plants remove CO2 from the atmosphere without causing any O2 changes, just as cement plants do, differing only in the direction of CO2 exchange with the atmosphere.
Kazuki Kamezaki, Sebastian O. Danielache, Shigeyuki Ishidoya, Takahisa Maeda, and Shohei Murayama
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2023-209, https://doi.org/10.5194/amt-2023-209, 2023
Revised manuscript not accepted
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Recently, MIRA Pico, a portable continuous carbonyl sulfide (COS) concentration analyzer using mid-infrared absorption, has been released. MIRA Pico has a lower cost and is smaller than conventional laser COS analyzers. However, actual COS atmospheric measurement results using MIRA Pico have not yet been reported. In this study, we modified and tested the MIRA Pico for atmospheric COS concentration measurements. We used the modified MIRA Pico for observations at Tsukuba, Japan.
Mathew Lipson, Sue Grimmond, Martin Best, Winston T. L. Chow, Andreas Christen, Nektarios Chrysoulakis, Andrew Coutts, Ben Crawford, Stevan Earl, Jonathan Evans, Krzysztof Fortuniak, Bert G. Heusinkveld, Je-Woo Hong, Jinkyu Hong, Leena Järvi, Sungsoo Jo, Yeon-Hee Kim, Simone Kotthaus, Keunmin Lee, Valéry Masson, Joseph P. McFadden, Oliver Michels, Wlodzimierz Pawlak, Matthias Roth, Hirofumi Sugawara, Nigel Tapper, Erik Velasco, and Helen Claire Ward
Earth Syst. Sci. Data, 14, 5157–5178, https://doi.org/10.5194/essd-14-5157-2022, https://doi.org/10.5194/essd-14-5157-2022, 2022
Short summary
Short summary
We describe a new openly accessible collection of atmospheric observations from 20 cities around the world, capturing 50 site years. The observations capture local meteorology (temperature, humidity, wind, etc.) and the energy fluxes between the land and atmosphere (e.g. radiation and sensible and latent heat fluxes). These observations can be used to improve our understanding of urban climate processes and to test the accuracy of urban climate models.
Nobuyuki Aoki, Shigeyuki Ishidoya, Shohei Murayama, and Nobuhiro Matsumoto
Atmos. Meas. Tech., 15, 5969–5983, https://doi.org/10.5194/amt-15-5969-2022, https://doi.org/10.5194/amt-15-5969-2022, 2022
Short summary
Short summary
The CO2 concentration in a cylinder is affected by carbon dioxide (CO2) adsorption to a cylinder’s internal surface and fractionation of CO2 and air in the preparation of standard mixtures. We demonstrate that the effects make the CO2 molar fractions deviate in standard mixtures prepared by diluting pure CO2 with air three times. This means that CO2 standard gases are difficult to gravimetrically prepare through multistep dilution.
Shigeyuki Ishidoya, Kazuhiro Tsuboi, Yosuke Niwa, Hidekazu Matsueda, Shohei Murayama, Kentaro Ishijima, and Kazuyuki Saito
Atmos. Chem. Phys., 22, 6953–6970, https://doi.org/10.5194/acp-22-6953-2022, https://doi.org/10.5194/acp-22-6953-2022, 2022
Short summary
Short summary
The atmospheric O2 / N2 ratio and CO2 concentration over the western North Pacific are presented. We found significant modification of the seasonal APO cycle in the middle troposphere due to the interhemispheric mixing of air. APO driven by the net marine biological activities indicated annual sea–air O2 flux during El Niño. Terrestrial biospheric and oceanic CO2 uptakes during 2012–2019 were estimated to be 1.8 and 2.8 Pg C a−1, respectively.
Shohei Nomura, Manish Naja, M. Kawser Ahmed, Hitoshi Mukai, Yukio Terao, Toshinobu Machida, Motoki Sasakawa, and Prabir K. Patra
Atmos. Chem. Phys., 21, 16427–16452, https://doi.org/10.5194/acp-21-16427-2021, https://doi.org/10.5194/acp-21-16427-2021, 2021
Short summary
Short summary
Long-term measurements of greenhouse gases (GHGs) in India and Bangladesh unveiled specific characteristics in their variations in these regions. Plants including rice cultivated in winter and summer strongly affected seasonal variations and levels in CO2 and CH4. Long-term variability of GHGs showed quite different features in their growth rates from those in Mauna Loa. GHG trends in this region seemed to be hardly affected by El Niño–Southern Oscillation (ENSO).
Nobuyuki Aoki, Shigeyuki Ishidoya, Yasunori Tohjima, Shinji Morimoto, Ralph F. Keeling, Adam Cox, Shuichiro Takebayashi, and Shohei Murayama
Atmos. Meas. Tech., 14, 6181–6193, https://doi.org/10.5194/amt-14-6181-2021, https://doi.org/10.5194/amt-14-6181-2021, 2021
Short summary
Short summary
Observing the minimal long-term change in atmospheric O2 molar fraction combined with CO2 observation enables us to estimate terrestrial biospheric and oceanic CO2 uptakes separately. In this study, we firstly identified the span offset between the laboratory O2 scales using our developed high-precision standard mixtures, suggesting that the result may allow us to estimate terrestrial biospheric and oceanic CO2 uptakes precisely.
Shigeyuki Ishidoya, Satoshi Sugawara, Yasunori Tohjima, Daisuke Goto, Kentaro Ishijima, Yosuke Niwa, Nobuyuki Aoki, and Shohei Murayama
Atmos. Chem. Phys., 21, 1357–1373, https://doi.org/10.5194/acp-21-1357-2021, https://doi.org/10.5194/acp-21-1357-2021, 2021
Short summary
Short summary
The surface Ar / N2 ratio showed not only secular increasing trends, but also interannual variations in phase with the global ocean heat content (OHC). Sensitivity test by using a two-dimensional model indicated that the secular trend in the Ar / N2 ratio is modified by the gravitational separation in the stratosphere. The analytical results imply that the surface Ar/N2 ratio is an important tracer for detecting spatiotemporally integrated changes in OHC and stratospheric circulation.
Ikumi Oyabu, Kenji Kawamura, Kyotaro Kitamura, Remi Dallmayr, Akihiro Kitamura, Chikako Sawada, Jeffrey P. Severinghaus, Ross Beaudette, Anaïs Orsi, Satoshi Sugawara, Shigeyuki Ishidoya, Dorthe Dahl-Jensen, Kumiko Goto-Azuma, Shuji Aoki, and Takakiyo Nakazawa
Atmos. Meas. Tech., 13, 6703–6731, https://doi.org/10.5194/amt-13-6703-2020, https://doi.org/10.5194/amt-13-6703-2020, 2020
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Air in polar ice cores provides information on past atmosphere and climate. We present a new method for simultaneously measuring eight gases (CH4, N2O and CO2 concentrations; isotopic ratios of N2 and O2; elemental ratios between N2, O2 and Ar; and total air content) from single ice-core samples with high precision.
Yoichi Inai, Ryo Fujita, Toshinobu Machida, Hidekazu Matsueda, Yousuke Sawa, Kazuhiro Tsuboi, Keiichi Katsumata, Shinji Morimoto, Shuji Aoki, and Takakiyo Nakazawa
Atmos. Chem. Phys., 19, 7073–7103, https://doi.org/10.5194/acp-19-7073-2019, https://doi.org/10.5194/acp-19-7073-2019, 2019
Nobuyuki Aoki, Shigeyuki Ishidoya, Nobuhiro Matsumoto, Takuro Watanabe, Takuya Shimosaka, and Shohei Murayama
Atmos. Meas. Tech., 12, 2631–2646, https://doi.org/10.5194/amt-12-2631-2019, https://doi.org/10.5194/amt-12-2631-2019, 2019
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Observation of atmospheric O2 requires highly precise standard gas mixtures with uncertainty of less than 1 ppm for the O2 mole fraction or 5 per meg for O2 / N2. The uncertainty had not been achieved due unknown uncertainty factors in mass determination of the filled source gases. We first developed the primary standard mixtures with 1 ppm for the O2 mole fraction or 5 per meg by identifying and reducing the unknown uncertainty factors.
Dmitry Belikov, Satoshi Sugawara, Shigeyuki Ishidoya, Fumio Hasebe, Shamil Maksyutov, Shuji Aoki, Shinji Morimoto, and Takakiyo Nakazawa
Atmos. Chem. Phys., 19, 5349–5361, https://doi.org/10.5194/acp-19-5349-2019, https://doi.org/10.5194/acp-19-5349-2019, 2019
Satoshi Sugawara, Shigeyuki Ishidoya, Shuji Aoki, Shinji Morimoto, Takakiyo Nakazawa, Sakae Toyoda, Yoichi Inai, Fumio Hasebe, Chusaku Ikeda, Hideyuki Honda, Daisuke Goto, and Fanny A. Putri
Atmos. Chem. Phys., 18, 1819–1833, https://doi.org/10.5194/acp-18-1819-2018, https://doi.org/10.5194/acp-18-1819-2018, 2018
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This is the first research that shows concrete evidence of gravitational separation in the tropical stratosphere. This implies that gravitational separation occurs within the entire stratosphere, which gives us new insight into atmospheric dynamics.
Sakae Toyoda, Naohiro Yoshida, Shinji Morimoto, Shuji Aoki, Takakiyo Nakazawa, Satoshi Sugawara, Shigeyuki Ishidoya, Mitsuo Uematsu, Yoichi Inai, Fumio Hasebe, Chusaku Ikeda, Hideyuki Honda, and Kentaro Ishijima
Atmos. Chem. Phys., 18, 833–844, https://doi.org/10.5194/acp-18-833-2018, https://doi.org/10.5194/acp-18-833-2018, 2018
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By analysis of whole air samples collected by balloon-borne compact cryogenic samplers, we found that apparent isotope effect for stratospheric N2O between 25 and 30 km over the Equator is larger than that observed in other latitudes and that it is almost equal to the effect predicted by laboratory simulation experiments. These results suggest that equatorial middle stratosphere can be treated as an isolated region when we consider the decomposition of N2O by photochemical processes.
Yosuke Niwa, Yosuke Fujii, Yousuke Sawa, Yosuke Iida, Akihiko Ito, Masaki Satoh, Ryoichi Imasu, Kazuhiro Tsuboi, Hidekazu Matsueda, and Nobuko Saigusa
Geosci. Model Dev., 10, 2201–2219, https://doi.org/10.5194/gmd-10-2201-2017, https://doi.org/10.5194/gmd-10-2201-2017, 2017
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A new 4D-Var inversion system based on the icosahedral grid model, NICAM, is introduced and tested. Adding to the offline forward and adjoint models, this study has introduced the optimization method of POpULar; it does not require difficult decomposition of a matrix that establishes the correlation among the prior flux errors. In identical twin experiments of atmospheric CO2 inversion, the system successfully reproduces the spatiotemporal variations of the surface fluxes.
Yosuke Niwa, Hirofumi Tomita, Masaki Satoh, Ryoichi Imasu, Yousuke Sawa, Kazuhiro Tsuboi, Hidekazu Matsueda, Toshinobu Machida, Motoki Sasakawa, Boris Belan, and Nobuko Saigusa
Geosci. Model Dev., 10, 1157–1174, https://doi.org/10.5194/gmd-10-1157-2017, https://doi.org/10.5194/gmd-10-1157-2017, 2017
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We have developed forward and adjoint models based on NICAM-TM, as part of the 4D-Var system for atmospheric GHGs inversions. The models are computationally efficient enough to make the 4D-Var iterative calculation feasible. Trajectory analysis for high-CO2 concentration events are performed to test adjoint sensitivities; we also demonstrate the potential usefulness of our adjoint model for diagnosing tracer transport.
Shohei Nomura, Hitoshi Mukai, Yukio Terao, Toshinobu Machida, and Yukihiro Nojiri
Atmos. Meas. Tech., 10, 667–680, https://doi.org/10.5194/amt-10-667-2017, https://doi.org/10.5194/amt-10-667-2017, 2017
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We developed a battery-powered CO2 measurement system for monitoring at the summit of Mt. Fuji, which experiences severe environmental conditions without access to gridded electricity for 10 months. Our measurement system used 100 batteries to run the measurement unit during these months. CO2 mole fractions at Mt. Fuji demonstrated clear seasonal variation. The trend and the variability of the CO2 growth rate observed at Mt. Fuji was very similar to that of the Mauna Loa Observatory.
Makoto Inoue, Isamu Morino, Osamu Uchino, Takahiro Nakatsuru, Yukio Yoshida, Tatsuya Yokota, Debra Wunch, Paul O. Wennberg, Coleen M. Roehl, David W. T. Griffith, Voltaire A. Velazco, Nicholas M. Deutscher, Thorsten Warneke, Justus Notholt, John Robinson, Vanessa Sherlock, Frank Hase, Thomas Blumenstock, Markus Rettinger, Ralf Sussmann, Esko Kyrö, Rigel Kivi, Kei Shiomi, Shuji Kawakami, Martine De Mazière, Sabrina G. Arnold, Dietrich G. Feist, Erica A. Barrow, James Barney, Manvendra Dubey, Matthias Schneider, Laura T. Iraci, James R. Podolske, Patrick W. Hillyard, Toshinobu Machida, Yousuke Sawa, Kazuhiro Tsuboi, Hidekazu Matsueda, Colm Sweeney, Pieter P. Tans, Arlyn E. Andrews, Sebastien C. Biraud, Yukio Fukuyama, Jasna V. Pittman, Eric A. Kort, and Tomoaki Tanaka
Atmos. Meas. Tech., 9, 3491–3512, https://doi.org/10.5194/amt-9-3491-2016, https://doi.org/10.5194/amt-9-3491-2016, 2016
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In this study, we correct the biases of GOSAT XCO2 and XCH4 using TCCON data. To evaluate the effectiveness of our correction method, uncorrected/corrected GOSAT data are compared to independent XCO2 and XCH4 data derived from aircraft measurements. Consequently, we suggest that this method is effective for reducing the biases of the GOSAT data. We consider that our work provides GOSAT data users with valuable information and contributes to the further development of studies on greenhouse gases.
M. Inoue, I. Morino, O. Uchino, Y. Miyamoto, T. Saeki, Y. Yoshida, T. Yokota, C. Sweeney, P. P. Tans, S. C. Biraud, T. Machida, J. V. Pittman, E. A. Kort, T. Tanaka, S. Kawakami, Y. Sawa, K. Tsuboi, and H. Matsueda
Atmos. Meas. Tech., 7, 2987–3005, https://doi.org/10.5194/amt-7-2987-2014, https://doi.org/10.5194/amt-7-2987-2014, 2014
T. Sugita, Y. Kasai, Y. Terao, S. Hayashida, G. L. Manney, W. H. Daffer, H. Sagawa, M. Suzuki, M. Shiotani, K. A. Walker, C. D. Boone, and P. F. Bernath
Atmos. Meas. Tech., 6, 3099–3113, https://doi.org/10.5194/amt-6-3099-2013, https://doi.org/10.5194/amt-6-3099-2013, 2013
S. Ishidoya, S. Sugawara, S. Morimoto, S. Aoki, T. Nakazawa, H. Honda, and S. Murayama
Atmos. Chem. Phys., 13, 8787–8796, https://doi.org/10.5194/acp-13-8787-2013, https://doi.org/10.5194/acp-13-8787-2013, 2013
K. Tsuboi, H. Matsueda, Y. Sawa, Y. Niwa, M. Nakamura, D. Kuboike, K. Saito, H. Ohmori, S. Iwatsubo, H. Nishi, Y. Hanamiya, K. Tsuji, and Y. Baba
Atmos. Meas. Tech., 6, 1257–1270, https://doi.org/10.5194/amt-6-1257-2013, https://doi.org/10.5194/amt-6-1257-2013, 2013
A. Wada, H. Matsueda, S. Murayama, S. Taguchi, A. Kamada, M. Nosaka, K. Tsuboi, and Y. Sawa
Atmos. Chem. Phys., 12, 12119–12132, https://doi.org/10.5194/acp-12-12119-2012, https://doi.org/10.5194/acp-12-12119-2012, 2012
Related subject area
Subject: Gases | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Formation drivers and photochemical effects of ClNO2 in a coastal city of Southeast China
Significant influence of oxygenated volatile organic compounds on atmospheric chemistry: a case study in a typical industrial city in China
Global ground-based tropospheric ozone measurements: reference data and individual site trends (2000–2022) from the TOAR-II/HEGIFTOM project
Understanding summertime H2O2 chemistry in the North China Plain through observations and modeling studies
Volatile organic compound sources and impacts in an urban Mediterranean area (Marseille, France)
Short-lived organic nitrates in a suburban temperate forest: an indication of efficient assimilation of reactive nitrogen by the biosphere?
Spatiotemporal variations in atmospheric CH4 concentrations and enhancements in northern China based on a comprehensive dataset: ground-based observations, TROPOMI data, inventory data, and inversions
Marine emissions and trade winds control the atmospheric nitrous oxide in the Galapagos Islands
Measurement report: A complex street-level air quality observation campaign in a heavy-traffic area utilizing the multivariate adaptive regression splines method for field calibration of low-cost sensors
The impact of organic nitrates on summer ozone formation in Shanghai, China
Differences in the key volatile organic compound species between their emitted and ambient concentrations in ozone formation
Tracing Ammonia Emission Sources in California's Salton Sea Region: Insights from Airborne Longwave-Infrared Hyperspectral Imaging and Ground Monitoring
Mechanistic insights into chloroacetic acid production from atmospheric multiphase volatile organic compound–chlorine chemistry
Accurate elucidation of oxidation under heavy ozone pollution: a full suite of radical measurements in the chemically complex atmosphere
Carbonyl compounds from typical combustion sources: emission characteristics, influencing factors, and their contribution to ozone formation
Emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from different cumulative-mileage diesel vehicles at various ambient temperatures
Characterization of nitrous acid and its potential effects on secondary pollution in the warm season in Beijing urban areas
Vertical changes in volatile organic compounds (VOCs) and impacts on photochemical ozone formation
Airborne quantification of Angolan offshore oil and gas methane emissions
Diurnal, seasonal, and interannual variations in δ(18O) of atmospheric O2 and its application to evaluate natural and anthropogenic changes in oxygen, carbon, and water cycles
Cloud processing of dimethyl sulfide (DMS) oxidation products limits sulfur dioxide (SO2) and carbonyl sulfide (OCS) production in the eastern North Atlantic marine boundary layer
Atmospheric carbonyl compounds are crucial in regional ozone heavy pollution: insights from the Chengdu Plain Urban Agglomeration, China
Evaluating urban methane emissions and their attributes in a megacity, Osaka, Japan, via mobile and eddy covariance measurements
Ozone (O3) observations in Saxony, Germany for 1997–2020: Trends, modelling and implications for O3 control
Understanding summertime peroxyacetyl nitrate (PAN) formation and its relation to aerosol pollution: insights from high-resolution measurements and modeling
Measurement report: Exploring the variations in ambient BTEX in urban Europe and their environmental health implications
Seasonal air concentration variability, gas–particle partitioning, precipitation scavenging, and air–water equilibrium of organophosphate esters in southern Canada
Tracing elevated abundance of CH2Cl2 in the subarctic upper troposphere to the Asian Summer Monsoon
Measurement report: Surface exchange fluxes of HONO during the growth process of paddy fields in the Huaihe River Basin, China
Hemispheric differences in ozone across the stratosphere-troposphere exchange region
Molecular and seasonal characteristics of organic vapors in urban Beijing: insights from Vocus-PTR measurements
BVOC and speciated monoterpene concentrations and fluxes at a Scandinavian boreal forest
The variations in volatile organic compounds based on the policy change for Omicron in the traffic hub of Zhengzhou
On the dynamics of ozone depletion events at Villum Research Station in the High Arctic
Measurement report: Long-term measurements of surface ozone and trends in semi-natural sub-Saharan African ecosystems
Characterization of biogenic volatile organic compounds and their oxidation products in a stressed spruce-dominated forest close to a biogas power plant
Reactive chlorine-, sulfur-, and nitrogen-containing volatile organic compounds impact atmospheric chemistry in the megacity of Delhi during both clean and extremely polluted seasons
Analysis of the day-to-day variability of ozone vertical profiles in the lower troposphere during the 2022 Paris ACROSS campaign
Ozone deposition measurements over wheat fields in the North China Plain: variability and related factors of deposition flux and velocity
Consistency evaluation of tropospheric ozone from ozonesonde and IAGOS (In-service Aircraft for a Global Observing System) observations: vertical distribution, ozonesonde types, and station–airport distance
CO2 and CO temporal variability over Mexico City from ground-based total column and surface measurements
Investigating carbonyl compounds above the Amazon rainforest using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) with NO+ chemical ionization
Measurement report: In-flight and ground-based measurements of nitrogen oxide emissions from latest-generation jet engines and 100 % sustainable aviation fuel
Observation and modelling of atmospheric OH and HO2 radicals at a subtropical rural site and implications for secondary pollutants
Measurement report: Sources, sinks, and lifetime of NOx in a suburban temperate forest at night
Measurement report: Urban ammonia and amines in Houston, Texas
Biomass-burning sources control ambient particulate matter, but traffic and industrial sources control volatile organic compound (VOC) emissions and secondary-pollutant formation during extreme pollution events in Delhi
Multi-year observations of variable incomplete combustion in the New York megacity
Observations of the vertical distributions of summertime atmospheric pollutants in Nam Co: OH production and source analysis
Measurement report: Elevated atmospheric ammonia may promote particle pH and HONO formation – insights from the COVID-19 pandemic
Gaojie Chen, Xiaolong Fan, Haichao Wang, Yee Jun Tham, Ziyi Lin, Xiaoting Ji, Lingling Xu, Baoye Hu, and Jinsheng Chen
Atmos. Chem. Phys., 25, 7815–7828, https://doi.org/10.5194/acp-25-7815-2025, https://doi.org/10.5194/acp-25-7815-2025, 2025
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Our study revealed that the nighttime heterogeneous dinitrogen pentoxide (N2O5) uptake process was the major contributor of nitryl chloride (ClNO2) sources, while nitrate photolysis may promote the elevation of daytime ClNO2 concentrations. The rates of alkane oxidation by chlorine (Cl) radical in the early morning exceeded those by OH radical, significantly promoted the formation of ROx and ozone (O3), and further enhanced the atmospheric oxidation capacity levels.
Jingwen Dai, Kun Zhang, Yanli Feng, Xin Yi, Rui Li, Jin Xue, Qing Li, Lishu Shi, Jiaqiang Liao, Yanan Yi, Fangting Wang, Liumei Yang, Hui Chen, Ling Huang, Jiani Tan, Yangjun Wang, and Li Li
Atmos. Chem. Phys., 25, 7467–7484, https://doi.org/10.5194/acp-25-7467-2025, https://doi.org/10.5194/acp-25-7467-2025, 2025
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Oxygenated volatile organic compounds (OVOCs) are important ozone (O3) precursors. However, most O3 formation analysis based on the box model (OBM) does not include any OVOC constraint. To access the interference of OVOCs with O3 simulation, this study presents results from a field campaign and OBM analysis. Our results indicate that no OVOC constraint in the OBM can lead to overestimation of OVOCs, free radicals, and O3.
Roeland Van Malderen, Anne M. Thompson, Debra E. Kollonige, Ryan M. Stauffer, Herman G. J. Smit, Eliane Maillard Barras, Corinne Vigouroux, Irina Petropavlovskikh, Thierry Leblanc, Valérie Thouret, Pawel Wolff, Peter Effertz, David W. Tarasick, Deniz Poyraz, Gérard Ancellet, Marie-Renée De Backer, Stéphanie Evan, Victoria Flood, Matthias M. Frey, James W. Hannigan, José L. Hernandez, Marco Iarlori, Bryan J. Johnson, Nicholas Jones, Rigel Kivi, Emmanuel Mahieu, Glen McConville, Katrin Müller, Tomoo Nagahama, Justus Notholt, Ankie Piters, Natalia Prats, Richard Querel, Dan Smale, Wolfgang Steinbrecht, Kimberly Strong, and Ralf Sussmann
Atmos. Chem. Phys., 25, 7187–7225, https://doi.org/10.5194/acp-25-7187-2025, https://doi.org/10.5194/acp-25-7187-2025, 2025
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Tropospheric ozone is an important greenhouse gas and is an air pollutant. The time variability of tropospheric ozone is mainly driven by anthropogenic emissions. In this paper, we study the distribution and time variability of ozone from harmonized ground-based observations from five different measurement techniques. Our findings provide clear standard references for atmospheric models and evolving tropospheric ozone satellite data for the 2000–2022 period.
Can Ye, Pengfei Liu, Chaoyang Xue, Chenglong Zhang, Zhuobiao Ma, Chengtang Liu, Junfeng Liu, Keding Lu, Yujing Mu, and Yuanhang Zhang
Atmos. Chem. Phys., 25, 6991–7005, https://doi.org/10.5194/acp-25-6991-2025, https://doi.org/10.5194/acp-25-6991-2025, 2025
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This study investigates H2O2 chemistry in rural North China. The observed H2O2 showed distinct diurnal variations influenced by photochemical reactions. A box model revealed that H2O2 is primarily produced by HO2 recombination and removed mainly via particle uptake. Reductions in NOx, PM2.5, and alkanes raised H2O2 levels, while cutting alkenes, aromatics, CO, and HONO lowered them. A dual strategy focusing on VOC and NOx control is essential to reduce both H2O2 and ozone pollution.
Marvin Dufresne, Thérèse Salameh, Thierry Leonardis, Grégory Gille, Alexandre Armengaud, and Stéphane Sauvage
Atmos. Chem. Phys., 25, 5977–5999, https://doi.org/10.5194/acp-25-5977-2025, https://doi.org/10.5194/acp-25-5977-2025, 2025
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This paper discusses the 18-month-long measurement of non-methane hydrocarbons (NMHCs) in Marseille, where there was no measurement since early 2000, despite the impact of NMHCs on air quality and climate. Traffic-related sources are the largest contributor to NMHC concentrations in Marseille, and shipping strongly contributes to the formation of aerosols. Finally, the Covid-19 lockdown had an impact on NMHC concentrations, reaching a 50 % decrease for traffic-related sources.
Simone T. Andersen, Rolf Sander, Patrick Dewald, Laura Wüst, Tobias Seubert, Gunther N. T. E. Türk, Jan Schuladen, Max R. McGillen, Chaoyang Xue, Abdelwahid Mellouki, Alexandre Kukui, Vincent Michoud, Manuela Cirtog, Mathieu Cazaunau, Astrid Bauville, Hichem Bouzidi, Paola Formenti, Cyrielle Denjean, Jean-Claude Etienne, Olivier Garrouste, Christopher Cantrell, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 25, 5893–5909, https://doi.org/10.5194/acp-25-5893-2025, https://doi.org/10.5194/acp-25-5893-2025, 2025
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Measurements and modelling of reactive nitrogen gases observed in a suburban temperate forest in Rambouillet, France, circa 50 km southwest of Paris in 2022 indicate that the biosphere rapidly scavenges organic nitrates of mixed biogenic and anthropogenic origin, resulting in short lifetimes for, for example, alkyl nitrates and peroxy nitrates.
Pengfei Han, Ning Zeng, Bo Yao, Wen Zhang, Weijun Quan, Pucai Wang, Ting Wang, Minqiang Zhou, Qixiang Cai, Yuzhong Zhang, Ruosi Liang, Wanqi Sun, and Shengxiang Liu
Atmos. Chem. Phys., 25, 4965–4988, https://doi.org/10.5194/acp-25-4965-2025, https://doi.org/10.5194/acp-25-4965-2025, 2025
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Methane (CH4) is a potent greenhouse gas. Northern China contributes a large proportion of CH4 emissions, yet large observation gaps exist. Here we compiled a comprehensive dataset, which is publicly available, that includes ground-based, satellite-based, inventory, and modeling results to show the CH4 concentrations, enhancements, and spatial–temporal variations. The data can benefit the research community and policy-makers for future observations, atmospheric inversions, and policy-making.
Timur Cinay, Dickon Young, Nazaret Narváez Jimenez, Cristina Vintimilla-Palacios, Ariel Pila Alonso, Paul B. Krummel, William Vizuete, and Andrew R. Babbin
Atmos. Chem. Phys., 25, 4703–4718, https://doi.org/10.5194/acp-25-4703-2025, https://doi.org/10.5194/acp-25-4703-2025, 2025
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We present the initial 15 months of nitrous oxide measurements from the Galapagos Emissions Monitoring Station. The observed variability in atmospheric mole fractions during this period can be linked to several factors: seasonal variations in trade wind speed and direction across the eastern Pacific, differences in the transport history of air masses sampled, and spatiotemporal heterogeneity in regional marine nitrous oxide emissions from the coastal upwelling systems of Peru and Chile.
Petra Bauerová, Josef Keder, Adriana Šindelářová, Ondřej Vlček, William Patiño, Pavel Krč, Jan Geletič, Hynek Řezníček, Martin Bureš, Kryštof Eben, Michal Belda, Jelena Radović, Vladimír Fuka, Radek Jareš, Igor Esau, and Jaroslav Resler
Atmos. Chem. Phys., 25, 4477–4504, https://doi.org/10.5194/acp-25-4477-2025, https://doi.org/10.5194/acp-25-4477-2025, 2025
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The study explored urban air quality in Prague using low-cost sensors and highlighted the multivariate adaptive regression splines (MARS) correction method's effectiveness in enhancing accuracy. Results showed traffic's impact on nitrogen dioxide levels and atmospheric dynamics on particulate matter. The research confirmed MARS-corrected sensors as cost-effective for monitoring, despite challenges like sensor ageing and data quality control.
Chunmeng Li, Xiaorui Chen, Haichao Wang, Tianyu Zhai, Xuefei Ma, Xinping Yang, Shiyi Chen, Min Zhou, Shengrong Lou, Xin Li, Limin Zeng, and Keding Lu
Atmos. Chem. Phys., 25, 3905–3918, https://doi.org/10.5194/acp-25-3905-2025, https://doi.org/10.5194/acp-25-3905-2025, 2025
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This study reports an observation of organic nitrate (including total peroxy nitrates and total alkyl nitrates) in Shanghai, China, during the summer of 2021, by homemade thermal dissociation cavity-enhanced absorption spectroscopy (TD-CEAS; Atmos. Meas. Tech., 14, 4033–4051, 2021). The distribution of organic nitrates and their effects on local ozone production are analyzed based on field observations in conjunction with model simulations.
Xudong Zheng and Shaodong Xie
Atmos. Chem. Phys., 25, 3807–3820, https://doi.org/10.5194/acp-25-3807-2025, https://doi.org/10.5194/acp-25-3807-2025, 2025
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To reduce uncertainties in identifying the key volatile organic compounds (VOCs) in ozone (O3) formation from ambient concentrations, this study comprehensively calculates the emitted VOC concentrations during both nighttime and daytime using the nitrate radical, O3, and hydroxyl radical reaction rates and ambient VOC concentrations. Based on the emitted concentrations, isoprene is one of the top three species contributing to O3 formation, which may be overlooked in observed concentrations.
Sina Hasheminassab, David M. Tratt, Olga V. Kalashnikova, Clement S. Chang, Morad Alvarez, Kerry N. Buckland, Michael J. Garay, Francesca M. Hopkins, Eric R. Keim, Le Kuai, Yaning Miao, Payam Pakbin, William C. Porter, and Mohammad H. Sowlat
EGUsphere, https://doi.org/10.5194/egusphere-2025-1378, https://doi.org/10.5194/egusphere-2025-1378, 2025
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Ammonia (NH3) is a key air pollutant linked to fine particle pollution, yet its sources remain poorly understood. Using airborne infrared imaging and ground sensors, we mapped NH3 emissions in California’s Salton Sea region with unprecedented detail. We found high emissions from farms, geothermal plants, and waste sites, including sources missing from inventories. These findings highlight the need for better NH3 monitoring to improve air quality models and guide pollution reduction strategies.
Mingxue Li, Men Xia, Chunshui Lin, Yifan Jiang, Weihang Sun, Yurun Wang, Yingnan Zhang, Maoxia He, and Tao Wang
Atmos. Chem. Phys., 25, 3753–3764, https://doi.org/10.5194/acp-25-3753-2025, https://doi.org/10.5194/acp-25-3753-2025, 2025
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Our field campaigns observed a strong diel pattern of chloroacetic acid as well as a strong correlation between its level and that of reactive chlorine species at a coastal site. Using quantum chemical calculations and box model simulation with an updated Master Chemical Mechanism, we found that the formation pathway of chloroacetic acid involved multiphase processes. Our study enhances understanding of atmospheric organic chlorine chemistry and emphasizes the importance of multiphase reactions.
Renzhi Hu, Guoxian Zhang, Haotian Cai, Jingyi Guo, Keding Lu, Xin Li, Shengrong Lou, Zhaofeng Tan, Changjin Hu, Pinhua Xie, and Wenqing Liu
Atmos. Chem. Phys., 25, 3011–3028, https://doi.org/10.5194/acp-25-3011-2025, https://doi.org/10.5194/acp-25-3011-2025, 2025
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A full suite of radical measurements (OH, HO2, RO2, and kOH) was established to accurately elucidate the limitations of oxidation in a chemically complex atmosphere. Sensitivity tests revealed that the incorporation of complex processes enabled a balance in both radical concentrations and coordinate ratios, effectively addressing the deficiency in the ozone generation mechanism. The full-chain radical detection bridged the gap between the photochemistry and the intensive oxidation level.
Yanjie Lu, Xinxin Feng, Yanli Feng, Minjun Jiang, Yu Peng, Tian Chen, and Yingjun Chen
EGUsphere, https://doi.org/10.5194/egusphere-2025-131, https://doi.org/10.5194/egusphere-2025-131, 2025
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The EFs of CCs from biomass burning (BB) is an order of magnitude higher than that from on-road sources. Fuel type determines the emission characteristics and composition of CCs. The formation of CCs from solid and liquid fuel sources is respectively controlled by combustion temperature and emission standards. In addition, biomass burning and agricultural machinery sources significantly contribute to the oxidizing capacity of regional atmospheres.
Shuwen Guo, Xuan Zheng, Xiao He, Lewei Zeng, Liqiang He, Xian Wu, Yifei Dai, Zihao Huang, Ting Chen, Shupei Xiao, Yan You, Sheng Xiang, Shaojun Zhang, Jingkun Jiang, and Ye Wu
Atmos. Chem. Phys., 25, 2695–2705, https://doi.org/10.5194/acp-25-2695-2025, https://doi.org/10.5194/acp-25-2695-2025, 2025
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We considered two potential influencing factors of heavy-duty diesel vehicle emissions that are rarely mentioned in the literature: cumulative mileage and ambient temperatures. The results suggest that prolonged use of heavy-duty diesel vehicles and low ambient temperatures leads to reduced engine combustion efficiency, which in turn increases tailpipe emissions significantly.
Junling Li, Chaofan Lian, Mingyuan Liu, Hao Zhang, Yongxin Yan, Yufei Song, Chun Chen, Jiaqi Wang, Haijie Zhang, Yanqin Ren, Yucong Guo, Weigang Wang, Yisheng Xu, Hong Li, Jian Gao, and Maofa Ge
Atmos. Chem. Phys., 25, 2551–2568, https://doi.org/10.5194/acp-25-2551-2025, https://doi.org/10.5194/acp-25-2551-2025, 2025
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As a key source of hydroxyl (OH) radical, nitrous acid (HONO) has attracted much attention for its important role in the atmospheric oxidant capacity (AOC) increase. In this study, we made a comparison of the ambient levels, variation patterns, sources, and formation pathway in the warm season on the basis of continuous intensive observations at an urban site of Beijing. This work highlights the importance of HONO for the AOC in the warm season.
Xiao-Bing Li, Bin Yuan, Yibo Huangfu, Suxia Yang, Xin Song, Jipeng Qi, Xianjun He, Sihang Wang, Yubin Chen, Qing Yang, Yongxin Song, Yuwen Peng, Guiqian Tang, Jian Gao, Dasa Gu, and Min Shao
Atmos. Chem. Phys., 25, 2459–2472, https://doi.org/10.5194/acp-25-2459-2025, https://doi.org/10.5194/acp-25-2459-2025, 2025
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Online vertical gradient measurements of volatile organic compounds (VOCs), ozone, and NOx were conducted based on a 325 m tall tower in urban Beijing. Vertical changes in the concentrations, compositions, key drivers, and environmental impacts of VOCs were analyzed in this study. We find that VOC species display differentiated vertical variation patterns and distinct roles in contributing to photochemical ozone formation with increasing height in the urban planetary boundary layer.
Alina Fiehn, Maximilian Eckl, Magdalena Pühl, Tiziana Bräuer, Klaus-Dirk Gottschaldt, Heinfried Aufmhoff, Lisa Eirenschmalz, Gregor Neumann, Felicitas Sakellariou, Daniel Sauer, Robert Baumann, Guilherme De Aguiar Ventura, Winne Nayole Cadete, Dário Luciano Zua, Manuel Xavier, Paulo Correia, and Anke Roiger
EGUsphere, https://doi.org/10.5194/egusphere-2025-635, https://doi.org/10.5194/egusphere-2025-635, 2025
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In September 2022, the METHANE-To-Go Africa (MTGA) campaign, part of UNEP’s IMEO Methane Science Studies, conducted the first CH₄ emissions measurements from West Africa’s offshore oil and gas sector. Using an aircraft-based mass balance method, emissions from Angolan offshore facilities were quantified. Older, low-producing facilities showed higher emissions than newer ones. High-emission events were observed, highlighting the need for targeted monitoring and mitigation efforts.
Shigeyuki Ishidoya, Satoshi Sugawara, and Atsushi Okazaki
Atmos. Chem. Phys., 25, 1965–1987, https://doi.org/10.5194/acp-25-1965-2025, https://doi.org/10.5194/acp-25-1965-2025, 2025
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The 18O/16O ratio of atmospheric oxygen, δatm(18O), is higher than that of ocean water due to isotopic effects during biospheric activities. This is known as the Dole–Morita effect, and its millennial-scale variations are recorded in ice cores. However, small variations of δatm(18O) in the present day have never been detected so far. This paper presents the first observations of diurnal, seasonal, and secular variations in δatm(18O) and applies them to evaluate oxygen, carbon, and water cycles.
Delaney B. Kilgour, Christopher M. Jernigan, Olga Garmash, Sneha Aggarwal, Shengqian Zhou, Claudia Mohr, Matt E. Salter, Joel A. Thornton, Jian Wang, Paul Zieger, and Timothy H. Bertram
Atmos. Chem. Phys., 25, 1931–1947, https://doi.org/10.5194/acp-25-1931-2025, https://doi.org/10.5194/acp-25-1931-2025, 2025
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We report simultaneous measurements of dimethyl sulfide (DMS) and hydroperoxymethyl thioformate (HPMTF) in the eastern North Atlantic. We use an observationally constrained box model to show that cloud loss is the dominant sink of HPMTF in this region over 6 weeks, resulting in large reductions in DMS-derived products that contribute to aerosol formation and growth. Our findings indicate that fast cloud processing of HPMTF must be included in global models to accurately capture the sulfur cycle.
Jiemeng Bao, Xin Zhang, Zhenhai Wu, Li Zhou, Jun Qian, Qinwen Tan, Fumo Yang, Junhui Chen, Yunfeng Li, Hefan Liu, Liqun Deng, and Hong Li
Atmos. Chem. Phys., 25, 1899–1916, https://doi.org/10.5194/acp-25-1899-2025, https://doi.org/10.5194/acp-25-1899-2025, 2025
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We studied carbonyl compounds' role in ozone pollution in the Chengdu Plain Urban Agglomeration, China. During heavy pollution in August 2019, we measured carbonyls at nine sites and analyzed their impact. Areas with higher carbonyl levels, like Chengdu, had worse ozone pollution. While their abundance matters, chemical reactions with other pollutants are the main drivers. Our findings show regional cooperation is vital to reducing ozone pollution effectively.
Masahito Ueyama, Taku Umezawa, Yukio Terao, Mark Lunt, and James Lawrence France
EGUsphere, https://doi.org/10.5194/egusphere-2024-3926, https://doi.org/10.5194/egusphere-2024-3926, 2025
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Methane (CH4) emissions were measured in Megacity Osaka, Japan, using mobile and eddy covariance methods. The CH4 emissions were much higher than those reported in local inventories, with natural gas contributing up to 74 % of the emissions. Several CH4 sources not accounted for in current inventories were identified. These results emphasize the need for more comprehensive emissions tracking in urban areas to enhance climate change mitigation efforts.
Yaru Wang, Dominik van Pinxteren, Andreas Tilgner, Erik Hans Hoffmann, Max Hell, Susanne Bastian, and Hartmut Herrmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-4202, https://doi.org/10.5194/egusphere-2024-4202, 2025
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Tropospheric ground-level ozone (O3) is a global air-quality pollutant and greenhouse gas. Long-term O3 trends from 16 stations in Saxony, Germany, were compared over three periods, revealing worsened O3 pollution over the last decade. O3 formation has been volatile organic compound (VOC)-limited at traffic and urban sites for the past 20 years. To mitigate O3 pollution, moderate nitrogen oxides and additional VOC controls, particularly in solvent use, should be prioritized in the coming years.
Baoye Hu, Naihua Chen, Rui Li, Mingqiang Huang, Jinsheng Chen, Youwei Hong, Lingling Xu, Xiaolong Fan, Mengren Li, Lei Tong, Qiuping Zheng, and Yuxiang Yang
Atmos. Chem. Phys., 25, 905–921, https://doi.org/10.5194/acp-25-905-2025, https://doi.org/10.5194/acp-25-905-2025, 2025
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Box modeling with the Master Chemical Mechanism (MCM) was used to explore summertime peroxyacetyl nitrate (PAN) formation and its link to aerosol pollution under high-ozone conditions. The MCM model is effective in the study of PAN photochemical formation and performed better during the clean period than the haze period. Machine learning analysis identified ammonia, nitrate, and fine particulate matter as the top three factors contributing to simulation bias.
Xiansheng Liu, Xun Zhang, Marvin Dufresne, Tao Wang, Lijie Wu, Rosa Lara, Roger Seco, Marta Monge, Ana Maria Yáñez-Serrano, Marie Gohy, Paul Petit, Audrey Chevalier, Marie-Pierre Vagnot, Yann Fortier, Alexia Baudic, Véronique Ghersi, Grégory Gille, Ludovic Lanzi, Valérie Gros, Leïla Simon, Heidi Héllen, Stefan Reimann, Zoé Le Bras, Michelle Jessy Müller, David Beddows, Siqi Hou, Zongbo Shi, Roy M. Harrison, William Bloss, James Dernie, Stéphane Sauvage, Philip K. Hopke, Xiaoli Duan, Taicheng An, Alastair C. Lewis, James R. Hopkins, Eleni Liakakou, Nikolaos Mihalopoulos, Xiaohu Zhang, Andrés Alastuey, Xavier Querol, and Thérèse Salameh
Atmos. Chem. Phys., 25, 625–638, https://doi.org/10.5194/acp-25-625-2025, https://doi.org/10.5194/acp-25-625-2025, 2025
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This study examines BTEX (benzene, toluene, ethylbenzene, xylenes) pollution in urban areas across seven European countries. Analyzing data from 22 monitoring sites, we found traffic and industrial activities significantly impact BTEX levels, with peaks during rush hours. The risk from BTEX exposure remains moderate, especially in high-traffic and industrial zones, highlighting the need for targeted air quality management to protect public health and improve urban air quality.
Yuening Li, Faqiang Zhan, Chubashini Shunthirasingham, Ying Duan Lei, Jenny Oh, Amina Ben Chaaben, Zhe Lu, Kelsey Lee, Frank A. P. C. Gobas, Hayley Hung, and Frank Wania
Atmos. Chem. Phys., 25, 459–472, https://doi.org/10.5194/acp-25-459-2025, https://doi.org/10.5194/acp-25-459-2025, 2025
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Organophosphate esters are important humanmade trace contaminants. Measuring them in the atmospheric gas phase, particles, precipitation, and surface water in Canada, we explore seasonal concentration variability, gas–particle partitioning, precipitation scavenging, and the air–water equilibrium. Whereas higher summer concentrations and efficient precipitation scavenging conform with expectations, the lack of a relationship between compound volatility and gas–particle partitioning is puzzling.
Markus Jesswein, Valentin Lauther, Nicolas Emig, Peter Hoor, Timo Keber, Hans-Christoph Lachnitt, Linda Ort, Tanja Schuck, Johannes Strobel, Ronja Van Luijt, C. Michael Volk, Franziska Weyland, and Andreas Engel
EGUsphere, https://doi.org/10.5194/egusphere-2024-3946, https://doi.org/10.5194/egusphere-2024-3946, 2025
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The study investigates transport within the Asian Summer Monsoon, focussing on how CH2Cl2 reaches the subarctic tropopause region. Using data from the PHILEAS campaign in 2023, events with increased mixing ratios were detected. Their origin, the transport paths to the tropopause region and the potential entry into the stratosphere were analysed. The East Asian Summer Monsoon was identified as the main transport pathway, with only a small contribution to the stratosphere in the following days.
Fanhao Meng, Baobin Han, Min Qin, Wu Fang, Ke Tang, Dou Shao, Zhitang Liao, Jun Duan, Yan Feng, Yong Huang, Ting Ni, and Pinhua Xie
Atmos. Chem. Phys., 24, 14191–14208, https://doi.org/10.5194/acp-24-14191-2024, https://doi.org/10.5194/acp-24-14191-2024, 2024
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Comprehensive observations of HONO and NOx fluxes were conducted over paddy fields in the Huaihe River Basin. Consecutive peaks in HONO and NO fluxes suggest a potentially enhanced release of HONO and NO due to soil tillage, whereas waterlogged soil may inhibit microbial nitrification processes following irrigation. Notably, biological processes and light-driven NO2 reactions at the surface may serve as sources of HONO and influence the local HONO budget during rotary tillage.
Rodrigo J. Seguel, Charlie Opazo, Yann Cohen, Owen R. Cooper, Laura Gallardo, Björn-Martin Sinnhuber, Florian Obersteiner, Andreas Zahn, Peter Hoor, and Susanne Rohs
EGUsphere, https://doi.org/10.5194/egusphere-2024-3719, https://doi.org/10.5194/egusphere-2024-3719, 2024
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We explored differences in ozone levels between the Northern and Southern Hemispheres in the Stratosphere-troposphere exchange region. Using unique data from a research aircraft, we found significantly lower ozone levels (with stratospheric character) in the Southern Hemisphere, especially during years of severe ozone depletion. A Sudden Stratospheric Warming event in 2019 increased Southern Hemisphere ozone levels, highlighting the relationship between atmospheric events and ozone distribution.
Zhaojin An, Rujing Yin, Xinyan Zhao, Xiaoxiao Li, Yuyang Li, Yi Yuan, Junchen Guo, Yiqi Zhao, Xue Li, Dandan Li, Yaowei Li, Dongbin Wang, Chao Yan, Kebin He, Douglas R. Worsnop, Frank N. Keutsch, and Jingkun Jiang
Atmos. Chem. Phys., 24, 13793–13810, https://doi.org/10.5194/acp-24-13793-2024, https://doi.org/10.5194/acp-24-13793-2024, 2024
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Online Vocus-PTR measurements show the compositions and seasonal variations in organic vapors in urban Beijing. With enhanced sensitivity and mass resolution, various species at a level of sub-parts per trillion (ppt) and organics with multiple oxygens (≥ 3) were observed. The fast photooxidation process in summer leads to an increase in both concentration and proportion of organics with multiple oxygens, while, in other seasons, the variations in them could be influenced by mixed sources.
Ross Charles Petersen, Thomas Holst, Cheng Wu, Radovan Krejci, Jeremy Chan, Claudia Mohr, and Janne Rinne
EGUsphere, https://doi.org/10.5194/egusphere-2024-3410, https://doi.org/10.5194/egusphere-2024-3410, 2024
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Ecosystem-scale emissions of biogenic volatile organic compounds (BVOCs) are important for atmospheric chemistry. Here we investigate boreal BVOC fluxes from a forest in central Sweden. BVOC fluxes were measured above-canopy using proton-transfer-reaction mass spectrometry, while compound-specific monoterpene (MT) fluxes were assessed using a concentration gradient method. We also evaluate the impact of chemical degradation on observed sesquiterpene (SQT) and nighttime MT fluxes.
Bowen Zhang, Dong Zhang, Zhe Dong, Xinshuai Song, Ruiqin Zhang, and Xiao Li
Atmos. Chem. Phys., 24, 13587–13601, https://doi.org/10.5194/acp-24-13587-2024, https://doi.org/10.5194/acp-24-13587-2024, 2024
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To gain insight into the impact of changes due to epidemic control policies, we undertook continuous online monitoring of volatile organic compounds (VOCs) at an urban site in Zhengzhou over a 2-month period. This study examines the characteristics of VOCs, their sources, and their temporal evolution. It also assesses the impact of the policy change on VOC pollution during the monitoring period, thus providing a basis for further research on VOC pollution and source control.
Jakob Boyd Pernov, Jens Liengaard Hjorth, Lise Lotte Sørensen, and Henrik Skov
Atmos. Chem. Phys., 24, 13603–13631, https://doi.org/10.5194/acp-24-13603-2024, https://doi.org/10.5194/acp-24-13603-2024, 2024
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Arctic ozone depletion events (ODEs) occur every spring and have vast implications for the oxidizing capacity, radiative balance, and mercury oxidation. In this study, we analyze ozone, ODEs, and their connection to meteorological and air mass history variables through statistical analyses, back trajectories, and machine learning (ML) at Villum Research Station. ODEs are favorable under sunny, calm conditions with air masses arriving from northerly wind directions with sea ice contact.
Hagninou Elagnon Venance Donnou, Aristide Barthélémy Akpo, Money Ossohou, Claire Delon, Véronique Yoboué, Dungall Laouali, Marie Ouafo-Leumbe, Pieter Gideon Van Zyl, Ousmane Ndiaye, Eric Gardrat, Maria Dias-Alves, and Corinne Galy-Lacaux
Atmos. Chem. Phys., 24, 13151–13182, https://doi.org/10.5194/acp-24-13151-2024, https://doi.org/10.5194/acp-24-13151-2024, 2024
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Ozone is a secondary air pollutant that is detrimental to human and plant health. A better understanding of its chemical evolution is a challenge for Africa, where it is still undersampled. Out of 14 sites examined (1995–2020), high levels of O3 are reported in southern Africa. The dominant chemical processes leading to O3 formation are identified. A decrease in O3 is observed at Katibougou (Mali) and Banizoumbou (Niger), and an increase is found at Zoétélé (Cameroon) and Skukuza (South Africa).
Junwei Song, Georgios I. Gkatzelis, Ralf Tillmann, Nicolas Brüggemann, Thomas Leisner, and Harald Saathoff
Atmos. Chem. Phys., 24, 13199–13217, https://doi.org/10.5194/acp-24-13199-2024, https://doi.org/10.5194/acp-24-13199-2024, 2024
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Biogenic volatile organic compounds (BVOCs) and organic aerosol (OA) particles were measured online in a stressed spruce-dominated forest. OA was mainly attributed to the monoterpene oxidation products. The mixing ratios of BVOCs were higher than the values previously measured in other temperate forests. The results demonstrate that BVOCs are influenced not only by meteorology and biogenic emissions but also by local anthropogenic emissions and subsequent chemical transformation processes.
Sachin Mishra, Vinayak Sinha, Haseeb Hakkim, Arpit Awasthi, Sachin D. Ghude, Vijay Kumar Soni, Narendra Nigam, Baerbel Sinha, and Madhavan N. Rajeevan
Atmos. Chem. Phys., 24, 13129–13150, https://doi.org/10.5194/acp-24-13129-2024, https://doi.org/10.5194/acp-24-13129-2024, 2024
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We quantified 111 gases using mass spectrometry to understand how seasonal and emission changes lead from clean air in the monsoon season to extremely polluted air in the post-monsoon season in Delhi. Averaged total mass concentrations (260 µg m-3) were > 4 times in polluted periods, driven by biomass burning emissions and reduced atmospheric ventilation. Reactive gaseous nitrogen, chlorine, and sulfur compounds hitherto unreported from such a polluted environment were discovered.
Gérard Ancellet, Camille Viatte, Anne Boynard, François Ravetta, Jacques Pelon, Cristelle Cailteau-Fischbach, Pascal Genau, Julie Capo, Axel Roy, and Philippe Nédélec
Atmos. Chem. Phys., 24, 12963–12983, https://doi.org/10.5194/acp-24-12963-2024, https://doi.org/10.5194/acp-24-12963-2024, 2024
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Characterization of ozone pollution in urban areas benefited from a measurement campaign in summer 2022 in the Paris region. The analysis is based on 21 d of lidar and aircraft observations. The main objective is an analysis of the sensitivity of ozone pollution to the micrometeorological processes in the urban atmospheric boundary layer and the transport of regional pollution. The paper also discusses to what extent satellite observations can track observed ozone plumes.
Xiaoyi Zhang, Wanyun Xu, Weili Lin, Gen Zhang, Jinjian Geng, Li Zhou, Huarong Zhao, Sanxue Ren, Guangsheng Zhou, Jianmin Chen, and Xiaobin Xu
Atmos. Chem. Phys., 24, 12323–12340, https://doi.org/10.5194/acp-24-12323-2024, https://doi.org/10.5194/acp-24-12323-2024, 2024
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Ozone (O3) deposition is a key process that removes surface O3, affecting air quality, ecosystems and climate change. We conducted O3 deposition measurement over a wheat canopy using a newly relaxed eddy accumulation flux system. Large variabilities in O3 deposition were detected, mainly determined by crop growth and modulated by various environmental factors. More O3 deposition observations over different surfaces are needed for exploring deposition mechanisms and model optimization.
Honglei Wang, David W. Tarasick, Jane Liu, Herman G. J. Smit, Roeland Van Malderen, Lijuan Shen, Romain Blot, and Tianliang Zhao
Atmos. Chem. Phys., 24, 11927–11942, https://doi.org/10.5194/acp-24-11927-2024, https://doi.org/10.5194/acp-24-11927-2024, 2024
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In this study, we identify 23 suitable pairs of sites from World Ozone and Ultraviolet Radiation Data Centre (WOUDC) and In-service Aircraft for a Global Observing System (IAGOS) datasets (1995 to 2021), compare the average vertical distributions of tropospheric O3 from ozonesonde and aircraft measurements, and analyze the differences based on ozonesonde type and station–airport distance.
Noémie Taquet, Wolfgang Stremme, María Eugenia González del Castillo, Victor Almanza, Alejandro Bezanilla, Olivier Laurent, Carlos Alberti, Frank Hase, Michel Ramonet, Thomas Lauvaux, Ke Che, and Michel Grutter
Atmos. Chem. Phys., 24, 11823–11848, https://doi.org/10.5194/acp-24-11823-2024, https://doi.org/10.5194/acp-24-11823-2024, 2024
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We characterize the variability in CO and CO2 emissions over Mexico City from long-term time-resolved Fourier transform infrared spectroscopy solar absorption and surface measurements from 2013 to 2021. Using the average intraday CO growth rate from total columns, the average CO / CO2 ratio and TROPOMI data, we estimate the interannual variability in the CO and CO2 anthropogenic emissions of Mexico City, highlighting the effect of an unprecedented drop in activity due to the COVID-19 lockdown.
Akima Ringsdorf, Achim Edtbauer, Bruna Holanda, Christopher Poehlker, Marta O. Sá, Alessandro Araújo, Jürgen Kesselmeier, Jos Lelieveld, and Jonathan Williams
Atmos. Chem. Phys., 24, 11883–11910, https://doi.org/10.5194/acp-24-11883-2024, https://doi.org/10.5194/acp-24-11883-2024, 2024
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We show the average height distribution of separately observed aldehydes and ketones over a day and discuss their rainforest-specific sources and sinks as well as their seasonal changes above the Amazon. Ketones have much longer atmospheric lifetimes than aldehydes and thus different implications for atmospheric chemistry. However, they are commonly observed together, which we overcome by measuring with a NO+ chemical ionization mass spectrometer for the first time in the Amazon rainforest.
Theresa Harlass, Rebecca Dischl, Stefan Kaufmann, Raphael Märkl, Daniel Sauer, Monika Scheibe, Paul Stock, Tiziana Bräuer, Andreas Dörnbrack, Anke Roiger, Hans Schlager, Ulrich Schumann, Magdalena Pühl, Tobias Schripp, Tobias Grein, Linda Bondorf, Charles Renard, Maxime Gauthier, Mark Johnson, Darren Luff, Paul Madden, Peter Swann, Denise Ahrens, Reetu Sallinen, and Christiane Voigt
Atmos. Chem. Phys., 24, 11807–11822, https://doi.org/10.5194/acp-24-11807-2024, https://doi.org/10.5194/acp-24-11807-2024, 2024
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Emissions from aircraft have a direct impact on our climate. Here, we present airborne and ground-based measurement data of nitrogen oxides that were collected in the exhaust of an Airbus aircraft. We study the impact of burning fossil and sustainable aviation fuel on nitrogen oxide emissions at different engine settings related to combustor temperature, pressure and fuel flow. Further, we compare observations with engine emission models.
Zhouxing Zou, Tianshu Chen, Qianjie Chen, Weihang Sun, Shichun Han, Zhuoyue Ren, Xinyi Li, Wei Song, Aoqi Ge, Qi Wang, Xiao Tian, Chenglei Pei, Xinming Wang, Yanli Zhang, and Tao Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3210, https://doi.org/10.5194/egusphere-2024-3210, 2024
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We measured ambient OH and HO2 concentrations at a subtropical rural site and compared our observations with model results. During warm periods, the model overestimated the concentrations of OH and HO2, leading to overestimation of ozone and nitric acid production. Our findings highlight the need to better understand how OH and HO2are formed and removed, which is important for accurate air quality and climate predictions.
Simone T. Andersen, Max R. McGillen, Chaoyang Xue, Tobias Seubert, Patrick Dewald, Gunther N. T. E. Türk, Jan Schuladen, Cyrielle Denjean, Jean-Claude Etienne, Olivier Garrouste, Marina Jamar, Sergio Harb, Manuela Cirtog, Vincent Michoud, Mathieu Cazaunau, Antonin Bergé, Christopher Cantrell, Sebastien Dusanter, Bénédicte Picquet-Varrault, Alexandre Kukui, Abdelwahid Mellouki, Lucy J. Carpenter, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 24, 11603–11618, https://doi.org/10.5194/acp-24-11603-2024, https://doi.org/10.5194/acp-24-11603-2024, 2024
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Using measurements of various trace gases in a suburban forest near Paris in the summer of 2022, we were able to gain insight into the sources and sinks of NOx (NO+NO2) with a special focus on their nighttime chemical and physical loss processes. NO was observed as a result of nighttime soil emissions when O3 levels were strongly depleted by deposition. NO oxidation products were not observed at night, indicating that soil and/or foliar surfaces are an efficient sink of reactive N.
Lee Tiszenkel, James H. Flynn, and Shan-Hu Lee
Atmos. Chem. Phys., 24, 11351–11363, https://doi.org/10.5194/acp-24-11351-2024, https://doi.org/10.5194/acp-24-11351-2024, 2024
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Ammonia and amines are important ingredients for aerosol formation in urban environments, but the measurements of these compounds are extremely challenging. Our observations show that urban ammonia and amines in Houston are emitted from urban sources, and diurnal variations in their concentrations are likely governed by gas-to-particle conversion and emissions.
Arpit Awasthi, Baerbel Sinha, Haseeb Hakkim, Sachin Mishra, Varkrishna Mummidivarapu, Gurmanjot Singh, Sachin D. Ghude, Vijay Kumar Soni, Narendra Nigam, Vinayak Sinha, and Madhavan N. Rajeevan
Atmos. Chem. Phys., 24, 10279–10304, https://doi.org/10.5194/acp-24-10279-2024, https://doi.org/10.5194/acp-24-10279-2024, 2024
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We use 111 volatile organic compounds (VOCs), PM10, and PM2.5 in a positive matrix factorization (PMF) model to resolve 11 pollution sources validated with chemical fingerprints. Crop residue burning and heating account for ~ 50 % of the PM, while traffic and industrial emissions dominate the gas-phase VOC burden and formation potential of secondary organic aerosols (> 60 %). Non-tailpipe emissions from compressed-natural-gas-fuelled commercial vehicles dominate the transport sector's PM burden.
Luke D. Schiferl, Cong Cao, Bronte Dalton, Andrew Hallward-Driemeier, Ricardo Toledo-Crow, and Róisín Commane
Atmos. Chem. Phys., 24, 10129–10142, https://doi.org/10.5194/acp-24-10129-2024, https://doi.org/10.5194/acp-24-10129-2024, 2024
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Carbon monoxide (CO) is an air pollutant and an important indicator of the incomplete combustion of fossil fuels in cities. Using 4 years of winter and spring observations in New York City, we found that both the magnitude and variability of CO from the metropolitan area are greater than expected. Transportation emissions cannot explain the missing and variable CO, which points to energy from buildings as a likely underappreciated source of urban air pollution and greenhouse gas emissions.
Chengzhi Xing, Cheng Liu, Chunxiang Ye, Jingkai Xue, Hongyu Wu, Xiangguang Ji, Jinping Ou, and Qihou Hu
Atmos. Chem. Phys., 24, 10093–10112, https://doi.org/10.5194/acp-24-10093-2024, https://doi.org/10.5194/acp-24-10093-2024, 2024
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We identified the contributions of ozone (O3) and nitrous acid (HONO) to the production rates of hydroxide (OH) in vertical space on the Tibetan Plateau (TP). A new insight was offered: the contributions of HONO and O3 to the production rates of OH on the TP are even greater than in lower-altitudes areas. This study enriches the understanding of vertical distribution of atmospheric components and explains the strong atmospheric oxidation capacity (AOC) on the TP.
Xinyuan Zhang, Lingling Wang, Nan Wang, Shuangliang Ma, Shenbo Wang, Ruiqin Zhang, Dong Zhang, Mingkai Wang, and Hongyu Zhang
Atmos. Chem. Phys., 24, 9885–9898, https://doi.org/10.5194/acp-24-9885-2024, https://doi.org/10.5194/acp-24-9885-2024, 2024
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This study highlights the importance of the redox reaction of NO2 with SO2 based on actual atmospheric observations. The particle pH in future China is expected to rise steadily. Consequently, this reaction could become a significant source of HONO in China. Therefore, it is crucial to coordinate the control of SO2, NOx, and NH3 emissions to avoid a rapid increase in the particle pH.
Cited articles
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Blaine, T. W., Keeling, R. F., and Paplawsky, W. J.: An improved inlet for precisely measuring the atmospheric Ar∕N2 ratio, Atmos. Chem. Phys., 6, 1181–1184, https://doi.org/10.5194/acp-6-1181-2006, 2006.
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Short summary
Atmospheric O2 and CO2 concentrations, along with CO2 flux, have been observed in a megacity, Tokyo, Japan. The O2 : CO2 exchange ratio for net turbulent O2 and CO2 fluxes (ORF) between the urban area and the overlaying atmosphere was obtained, and we applied it to estimate the diurnal cycles of CO2 fluxes from gas and liquid fuel consumption separately. We found simultaneous observations of ORF and CO2 flux are useful in validating CO2 emission inventories from statistical data.
Atmospheric O2 and CO2 concentrations, along with CO2 flux, have been observed in a megacity,...
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