Articles | Volume 25, issue 3
https://doi.org/10.5194/acp-25-1965-2025
© Author(s) 2025. 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-25-1965-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Feb 2025
Research article |
| 14 Feb 2025
| 14 Feb 2025
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
National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8569, Japan
Satoshi Sugawara
Miyagi University of Education, Sendai 980-0845, Japan
Atsushi Okazaki
Chiba University, Chiba 263-8522, Japan
Related authors
Zhenglun Yang, Yukio Terao, Thomas Lauvaux, Tomohiro Oda, Charbel Abdallah, Masahide Nishihashi, Makoto Saito, Hirofumi Ohyama, Shigeyuki Ishidoya, Hirofumi Sugawara, Toshinobu Machida, Motoki Sasakawa, and Yasunori Tohjima
EGUsphere, https://doi.org/10.5194/egusphere-2026-2178, https://doi.org/10.5194/egusphere-2026-2178, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Cities need accurate emission estimates for climate action. We compared five emission inventories over the Greater Tokyo Area using measurements from four sites and an atmospheric transport model. We found that measurements at the four sites show distinct features of the inventories in emission amount and spatial distribution. Site choice is important for evaluating urban emissions. These findings can help improve emission inventories, future urban observations and simulations.
Shigeyuki Ishidoya, Takahisa Maeda, Hidehiko Kikuno, Jumpei Fukumasu, Shinya Iwasaki, Sadao Eguchi, Rota Wagai, Kei Asada, Taku Nishimura, Takuhei Yamasaki, Shinji Suzuki, Shohei Murayama, Atsushi Yamamoto, Asaka Hasegawa, Satoshi Sugawara, Shuji Aoki, and Takakiyo Nakazawa
EGUsphere, https://doi.org/10.5194/egusphere-2026-2751, https://doi.org/10.5194/egusphere-2026-2751, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Soil chamber measurements of O2 and its δ(18O) and CO2 were conducted at a forest site and at agricultural fields. The O2:CO2 exchange ratios for soil–air fluxes were stable at the forest site but variable at agricultural fields. We partitioned measured CO2 fluxes into soil respiration and abiotic reactions to evaluate carbon dioxide removal rate for enhanced rock weathering. The isotopic effect of O2 for soil respiration was evaluated and we estimated its impact on the Dole–Morita effect.
Satoshi Sugawara, Ikumi Oyabu, Kenji Kawamura, Shigeyuki Ishidoya, Shinji Morimoto, Shuji Aoki, Takakiyo Nakazawa, Sakae Toyoda, and Hideyuki Honda
Atmos. Chem. Phys., 26, 1537–1563, https://doi.org/10.5194/acp-26-1537-2026, https://doi.org/10.5194/acp-26-1537-2026, 2026
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 of the kinetic fractionations of Kr, Xe, and Ne in the stratosphere. It was suggested that changes in the stratospheric circulation during glacial and interglacial cycles may have affected the noble gas elemental ratios in ice core samples.
Nobuyuki Aoki and Shigeyuki Ishidoya
Atmos. Meas. Tech., 18, 6053–6067, https://doi.org/10.5194/amt-18-6053-2025, https://doi.org/10.5194/amt-18-6053-2025, 2025
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
Atmos. Chem. Phys., 25, 11895–11917, https://doi.org/10.5194/acp-25-11895-2025, https://doi.org/10.5194/acp-25-11895-2025, 2025
Short summary
Short summary
We have collected stratospheric air samples using balloon-borne cryogenic samplers over Japan since 1985 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. We found that stratospheric δ13CO2 variations are governed by airborne production of 13C-depleted CO2 by CH4 oxidation, gravitational separation, and propagation of the decreasing tropospheric δ13CO2 trend into the stratosphere.
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, Shoji Matsuura, Trofim Maximov, Takafumi Miyama, Ryo Moriwaki, Hiroyuki Muraoka, Roman Petrov, Jun Suzuki, Shingo Taniguchi, and Kazuhito Ichii
Earth Syst. Sci. Data, 17, 3807–3833, https://doi.org/10.5194/essd-17-3807-2025, https://doi.org/10.5194/essd-17-3807-2025, 2025
Short summary
Short summary
The JapanFlux2024 dataset, created through collaboration across Japan and East Asia, includes eddy covariance data from 83 sites spanning 683 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; fosters global collaboration; and advances research in environmental science and regional climate dynamics.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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.
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.
Zhenglun Yang, Yukio Terao, Thomas Lauvaux, Tomohiro Oda, Charbel Abdallah, Masahide Nishihashi, Makoto Saito, Hirofumi Ohyama, Shigeyuki Ishidoya, Hirofumi Sugawara, Toshinobu Machida, Motoki Sasakawa, and Yasunori Tohjima
EGUsphere, https://doi.org/10.5194/egusphere-2026-2178, https://doi.org/10.5194/egusphere-2026-2178, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Cities need accurate emission estimates for climate action. We compared five emission inventories over the Greater Tokyo Area using measurements from four sites and an atmospheric transport model. We found that measurements at the four sites show distinct features of the inventories in emission amount and spatial distribution. Site choice is important for evaluating urban emissions. These findings can help improve emission inventories, future urban observations and simulations.
Saaya Hamamoto, Yoshinori Iizuka, Takuro Aizawa, Kaoru Kawakami, Mai Matsumoto, Sumito Matoba, Hayoung Bong, Kei Yoshimura, Atsushi Okazaki, Laura Jasmin Dietrich, Hans Christian Steen-Larsen, and Ryu Uemura
EGUsphere, https://doi.org/10.5194/egusphere-2026-3602, https://doi.org/10.5194/egusphere-2026-3602, 2026
This preprint is open for discussion and under review for Climate of the Past (CP).
Short summary
Short summary
We developed a new 150-year age scale for an ice core from southeast Greenland by matching its oxygen-isotope variations with climate-model simulations. The record resolves changes over several months and shows that snowfall remained nearly evenly distributed through the seasons from 1871 to 2020. This stability suggests that the regional balance of atmospheric circulation and moisture transport changed little at this site despite recent Arctic warming.
Shigeyuki Ishidoya, Takahisa Maeda, Hidehiko Kikuno, Jumpei Fukumasu, Shinya Iwasaki, Sadao Eguchi, Rota Wagai, Kei Asada, Taku Nishimura, Takuhei Yamasaki, Shinji Suzuki, Shohei Murayama, Atsushi Yamamoto, Asaka Hasegawa, Satoshi Sugawara, Shuji Aoki, and Takakiyo Nakazawa
EGUsphere, https://doi.org/10.5194/egusphere-2026-2751, https://doi.org/10.5194/egusphere-2026-2751, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
Soil chamber measurements of O2 and its δ(18O) and CO2 were conducted at a forest site and at agricultural fields. The O2:CO2 exchange ratios for soil–air fluxes were stable at the forest site but variable at agricultural fields. We partitioned measured CO2 fluxes into soil respiration and abiotic reactions to evaluate carbon dioxide removal rate for enhanced rock weathering. The isotopic effect of O2 for soil respiration was evaluated and we estimated its impact on the Dole–Morita effect.
Satoshi Sugawara, Ikumi Oyabu, Kenji Kawamura, Shigeyuki Ishidoya, Shinji Morimoto, Shuji Aoki, Takakiyo Nakazawa, Sakae Toyoda, and Hideyuki Honda
Atmos. Chem. Phys., 26, 1537–1563, https://doi.org/10.5194/acp-26-1537-2026, https://doi.org/10.5194/acp-26-1537-2026, 2026
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 of the kinetic fractionations of Kr, Xe, and Ne in the stratosphere. It was suggested that changes in the stratospheric circulation during glacial and interglacial cycles may have affected the noble gas elemental ratios in ice core samples.
Nobuyuki Aoki and Shigeyuki Ishidoya
Atmos. Meas. Tech., 18, 6053–6067, https://doi.org/10.5194/amt-18-6053-2025, https://doi.org/10.5194/amt-18-6053-2025, 2025
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.
Takahito Mitsui, Shunji Kotsuki, Naoya Fujiwara, Atsushi Okazaki, and Keita Tokuda
Nonlin. Processes Geophys., 32, 457–469, https://doi.org/10.5194/npg-32-457-2025, https://doi.org/10.5194/npg-32-457-2025, 2025
Short summary
Short summary
Extreme weather poses serious risks, making prevention crucial. Using the Lorenz 96 model as a testbed, we propose a bottom-up approach to mitigate extreme events via local interventions guided by multi-scenario ensemble forecasts. Unlike control-theoretic methods, our approach selects the best control scenario from available options. It achieves a high success rate of 99.4% while maintaining reasonable costs, offering a practical strategy to reduce extremes under limited control.
Atsushi Okazaki, Diego S. Carrió, Quentin Dalaiden, Jarrah Harrison-Lofthouse, Shunji Kotsuki, and Kei Yoshimura
Clim. Past, 21, 1801–1819, https://doi.org/10.5194/cp-21-1801-2025, https://doi.org/10.5194/cp-21-1801-2025, 2025
Short summary
Short summary
Data assimilation (DA) has been used to reconstruct paleoclimate fields. DA integrates model simulations and climate proxies based on their error sizes. Consequently, error information is vital for DA to function optimally. This study estimated observation errors using "innovation statistics" and demonstrated that DA with estimated errors outperformed previous studies.
Shunji Kotsuki, Kenta Shiraishi, and Atsushi Okazaki
Geosci. Model Dev., 18, 7215–7225, https://doi.org/10.5194/gmd-18-7215-2025, https://doi.org/10.5194/gmd-18-7215-2025, 2025
Short summary
Short summary
Artificial intelligence (AI) is playing a bigger role in weather forecasting, often competing with physical models. However, combining AI models with data assimilation, a process that improves weather forecasts by incorporating observation data, is still relatively unexplored. This study explored the coupling of ensemble data assimilation with an AI weather prediction model, ClimaX, which succeeded in employing weather forecasts stably by applying techniques conventionally used for physical models.
Satoshi Sugawara, Shinji Morimoto, Shigeyuki Ishidoya, Taku Umezawa, Shuji Aoki, Takakiyo Nakazawa, Sakae Toyoda, Kentaro Ishijima, Daisuke Goto, and Hideyuki Honda
Atmos. Chem. Phys., 25, 11895–11917, https://doi.org/10.5194/acp-25-11895-2025, https://doi.org/10.5194/acp-25-11895-2025, 2025
Short summary
Short summary
We have collected stratospheric air samples using balloon-borne cryogenic samplers over Japan since 1985 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. We found that stratospheric δ13CO2 variations are governed by airborne production of 13C-depleted CO2 by CH4 oxidation, gravitational separation, and propagation of the decreasing tropospheric δ13CO2 trend into the stratosphere.
Kenta Kurosawa, Atsushi Okazaki, Fumitoshi Kawasaki, and Shunji Kotsuki
Nonlin. Processes Geophys., 32, 293–307, https://doi.org/10.5194/npg-32-293-2025, https://doi.org/10.5194/npg-32-293-2025, 2025
Short summary
Short summary
We propose ensemble-based model predictive control (EnMPC), a novel method that improves the control of complex systems like the atmosphere by integrating control theory with data assimilation. Unlike traditional methods, which are computationally expensive, EnMPC uses ensemble simulations to efficiently handle uncertainties and optimize solutions. This approach reduces computational cost while maintaining accuracy, making it a promising step toward real-world applications in dynamic system control.
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, Shoji Matsuura, Trofim Maximov, Takafumi Miyama, Ryo Moriwaki, Hiroyuki Muraoka, Roman Petrov, Jun Suzuki, Shingo Taniguchi, and Kazuhito Ichii
Earth Syst. Sci. Data, 17, 3807–3833, https://doi.org/10.5194/essd-17-3807-2025, https://doi.org/10.5194/essd-17-3807-2025, 2025
Short summary
Short summary
The JapanFlux2024 dataset, created through collaboration across Japan and East Asia, includes eddy covariance data from 83 sites spanning 683 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; fosters global collaboration; and advances research in environmental science and regional climate dynamics.
Fumitoshi Kawasaki, Atsushi Okazaki, Kenta Kurosawa, Tadashi Tsuyuki, and Shunji Kotsuki
EGUsphere, https://doi.org/10.5194/egusphere-2025-1785, https://doi.org/10.5194/egusphere-2025-1785, 2025
Preprint archived
Short summary
Short summary
A major challenge in weather control aimed at mitigating extreme weather events is identifying effective control inputs under limited computational resources. This study proposes a novel control framework called model predictive control with foreseeing horizon, designed to efficiently control chaotic dynamical systems. Using a 40-variable chaotic dynamical model, the proposed method successfully mitigated extreme events and reduced computational cost compared to the conventional approach.
Toshiyuki Ohtsuka, Atsushi Okazaki, Masaki Ogura, and Shunji Kotsuki
EGUsphere, https://doi.org/10.48550/arXiv.2405.19546, https://doi.org/10.48550/arXiv.2405.19546, 2024
Preprint withdrawn
Short summary
Short summary
We utilize weather forecasts in the reverse direction and determine how much we should change the temperature or humidity of the atmosphere at a certain time to change the future rainfall as desired. Even though a weather phenomenon is complicated, we can superimpose the effects of small changes in the atmosphere and find suitable small changes to realize desirable rainfall by solving an optimization problem. We examine this idea on a realistic weather simulator and show it is promising.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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.
Taku Umezawa, Satoshi Sugawara, Kenji Kawamura, Ikumi Oyabu, Stephen J. Andrews, Takuya Saito, Shuji Aoki, and Takakiyo Nakazawa
Atmos. Chem. Phys., 22, 6899–6917, https://doi.org/10.5194/acp-22-6899-2022, https://doi.org/10.5194/acp-22-6899-2022, 2022
Short summary
Short summary
Greenhouse gas methane in the Arctic atmosphere has not been accurately reported for 1900–1980 from either direct observations or ice core reconstructions. By using trace gas data from firn (compacted snow layers above ice sheet), air samples at two Greenland sites, and a firn air transport model, this study suggests a likely range of the Arctic methane reconstruction for the 20th century. Atmospheric scenarios from two previous studies are also evaluated for consistency with the firn data sets.
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.
Cited articles
Adachi, Y., Kawamura, K., Armi, L., and Keeling, R. F.: Diffusive separation of the lower atmosphere, Science, 311, 1429, https://doi.org/10.1126/science.1121312, 2006.
Angert, A., Luz, B., and Yakir, D.: Fractionation of oxygen isotopes by respiration and diffusion in soils: Implications for the isotopic composition of atmospheric O2, Global Biogeochem. Cy., 15, 871–881, https://doi.org/10.1029/2000GB001371, 2001.
Angert, A., Barkan, E., Barnett, B., Brugnoli, E., Davidson, E. A., Fessenden, J., Maneepong, S., Panapitukkul, N., Randerson, J. T., Savage, K., Yakir, D., and Luz, B.: The contribution of soil respiration in tropical, temperate, and boreal forests to the 18O enrichment of atmospheric O2, Global Biogeochem. Cy., 17, 1089, https://doi.org/10.1029/2003GB002056, 2003.
Aoki, N., Ishidoya, S., Matsumoto, N., Watanabe, T., Shimosaka, T., and Murayama, S.: Preparation of primary standard mixtures for atmospheric oxygen measurements with less than 1 µmol mol−1 uncertainty for oxygen molar fractions, Atmos. Meas. Tech., 12, 2631–2646, https://doi.org/10.5194/amt-12-2631-2019, 2019.
Barkan, E. and Luz, B.: High precision measurements of 17O/16O and
Basu, S., Miller, J. B., and Lehman, S.: Separation of biospheric and fossil fuel fluxes of CO2 by atmospheric inversion of CO2 and 14CO2 measurements: Observation System Simulations, Atmos. Chem. Phys., 16, 5665–5683, https://doi.org/10.5194/acp-16-5665-2016, 2016.
Basu, S., Lehman, S. J., Miller, J. B., Andrews, A. E., Sweeney, C., Gurney, K. R., Xu, X., Southon, J., and Tans, P. P.: Estimating US fossil fuel CO2 emissions from measurements of 14C in atmospheric CO2, P. Natl. Acad. Sci. USA, 117, 13300–13307, 2020.
Battle, M. O., Munger, J. W., Conley, M., Sofen, E., Perry, R., Hart, R., Davis, Z., Scheckman, J., Woogerd, J., Graeter, K., Seekins, S., David, S., and Carpenter, J.: Atmospheric measurements of the terrestrial O2: CO2 exchange ratio of a midlatitude forest, Atmos. Chem. Phys., 19, 8687–8701, https://doi.org/10.5194/acp-19-8687-2019, 2019.
Bender, M., Sowers, T., and Labeyrie, L.: The Dole effect and its variations during the last 130 000 years as measured in the Vostok ice core, Global Biogeochem. Cy., 8, 363–376, 1994.
Bi, W., He, W., Zhou, Y., Weimin, J., Liu, Y., Liu, Y., Zhang, X., Wei, X., and Cheng, N.: A global 0.05° dataset for gross primary production of sunlit and shaded vegetation canopies from 1992 to 2020, Sci. Data, 9, 213, https://doi.org/10.1038/s41597-022-01309-2, 2022.
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.
Byrne, M. P. and O'Gorman, P. A.: Trends in continental temperature and humidity directly linked to ocean warming, P. Natl. Acad. Sci. USA, 115, 4863–4868, 2018.
Campbell, J. E., Berry, J. A., Seibt, U., Smith, S. J., Montzka, S. A., Launois, T. Belviso, S. Bopp, L., and Laine, M.: Large historical growth in global terrestrial gross primary production, Nature, 544, 84–87, https://doi.org/10.1038/nature22030, 2017.
Cernusak, L. A., Barbeta, A., Bush, R., Eichstaedt R., Ferrio, J., Flanagan, L., Gessler, A., Martín-Gómez, P., Hirl, R., Kahmen, A., Keitel., C., Lai, C., Munksgaard, N., Nelson, D., Ogée J., Roden, J., Schnyder, H., Voelker, S., Wang L., Stuart-Williams, H., Wingate, L., Yu, W., Zhao, L., and Cuntz, M.: Do 2H and 18O in leaf water reflect environmental drivers differently?, New Phytol., 235, 41–51, https://doi.org/10.1111/nph.18113, 2022.
Cohen, E. R., Cvitas, T., Frey, J. G., Holmstrom, B., Kuchitsu, K., Marquardt, R., Mills, I., Pavese, F., Quack, M., Stohner, J., Strauss, H., Takami, M., and Thor, A. J.: IUPAC Green Book: 3rd edn., RSC Publishing, ISBN 0854044337, ISBN-13 9780854044337, 2007.
Cuntz, M., Ciais, P., Hoffmann, G., Allison, C. E., Francey, R. J., Knorr, W., Tans, P. P., White, J. W. C., and Levin, I.: A comprehensive global three-dimensional model of δ18O in atmospheric CO2: 2. Mapping the atmospheric signal, J. Geophys. Res., 108, 4528, https://doi.org/10.1029/2002JD003154, 2003.
Craig, H.: Standard for reporting concentrations of deuterium and oxygen-18 in natural water, Science, 133, 1833–1834, 1961.
Dole, M.: The relative atomic weight of oxygen in water and in air, J. Am. Chem. Soc., 57, 2731, https://doi.org/10.1021/ja01315a511, 1935.
Dongmann, G., Forstel, H., and Wagener, K.: 18O-rich oxygen from land photosynthesis, Nat. New Biol., 240, 127–128, 1972.
Eddebbar, Y. A., Long, M. C., Resplandy, L., Rödenbeck, C., Rodgers, K. B., Manizza, M., and Keeling, R. F.: Impacts of ENSO on air-sea oxygen exchange: Observations and mechanisms, Global Biogeochem. Cy., 31, 901–921, https://doi.org/10.1002/2017GB005630, 2017.
Faassen, K. A. P., Nguyen, L. N. T., Broekema, E. R., Kers, B. A. M., Mammarella, I., Vesala, T., Pickers, P. A., Manning, A. C., Vilà-Guerau de Arellano, J., Meijer, H. A. J., Peters, W., and Luijkx, I. T.: Diurnal variability of atmospheric O2, CO2, and their exchange ratio above a boreal forest in southern Finland, Atmos. Chem. Phys., 23, 851–876, https://doi.org/10.5194/acp-23-851-2023, 2023.
Farquhar, G. D., von Caemmerer, S., and Berry, J. A.: A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species, Planta, 149, 78–90, 1980.
Farquhar, G. D., Lloyd, J., Taylor, J. A., Flanagan, L., Syvertsen, J. P., Hubick, K., Wong, S., and Ehleringer, J. R.: Vegetation effects on the isotope composition of oxygen in atmospheric CO2, Nature, 363, 439–443, https://doi.org/10.1038/363439a0, 1993.
Gamo, T., Tsutsumi, M., Sakai, H., Nakazawa, T., Tanaka, M., Honda, H., Kubo, H., and Itoh, T.: Carbon and oxygen isotopic ratios of carbon dioxide of a stratospheric profile over Japan, Tellus B, 41, 127–133, https://doi.org/10.1111/j.1600-0889.1989.tb00130.x, 1989.
Gonfiantini, R., Gratzui, S., and Tongiorgi, E.: Oxygen isotopic composition of water in leaves, in Use of Isotopes and Radiation in Soil-Plant Nutrition Studies, Tech. Rep. Ser. 206, 405–410 pp., IAEA, Vienna, 1965.
Graven, H., Fischer, M. L., Lueker T., Jeong, S., Guiderson, T. P., Keeling, R. F., Bambha R., Brophy, K., Callahan, W., and Cui, X.: Assessing fossil fuel CO2 emissions in California using atmospheric observations and models, Environ. Res. Lett., 13, 65007, https://doi.org/10.1088/1748-9326/aabd43, 2018.
Hoffmann, G., Suntz, M., Weber, C., Ciais, P., Friedlingstein, P., Heimann, M., Jouzel, J., Kaduk, J., Maier-Reimer, E., Seibt, U., and Six, K.: A model of the Earth's Dole effect, Global Biogeochem. Cy., 18, GB1008, https://doi.org/10.1029/2003GB002059, 2004.
Ishidoya, S.: Development of high precision measurement technique of the atmospheric O2/N2 ratio and its application to the global carbon cycle, Ph.D. thesis, Tohoku University, Sendai, 2003.
Ishidoya, S.: Dataset for “Diurnal, seasonal, and interannual variations in δ(18O) of atmospheric O2 and its application to evaluate natural/anthropogenic changes in oxygen, carbon, and water cycles” by Ishidoya et al., Zenodo [data set], https://doi.org/10.5281/zenodo.14221768, 2024.
Ishidoya, S. and Murayama, S.: Development of high precision continuous measuring system of the atmospheric O2/N2 and Ar/N2 ratios and its application to the observation in Tsukuba, Japan, Tellus B, 66, 22574, https://doi.org/10.3402/tellusb.v66.22574, 2014.
Ishidoya, S., Aoki, S. and Nakazawa, T.: High precision measurements of the atmospheric O2/N2 ratio on a mass spectrometer, J. Meteorol. Soc. Jpn. 81, 127–140, 2003.
Ishidoya, S., Murayama, S., Takamura, C., Kondo, H., Saigusa, N., Goto, D., Morimoto, S., Aoki, N., Aoki, S., and Nakazawa, T.: O2:CO2 exchange ratios observed in a cool temperate deciduous forest ecosystem of central Japan, Tellus B, 65, 21120, https://doi.org/10.3402/tellusb.v65i0.21120, 2013a.
Ishidoya, S., Sugawara, S., Morimoto, S., Aoki, S., Nakazawa, T., Honda, H., and Murayama, S.: Gravitational separation in the stratosphere – a new indicator of atmospheric circulation, Atmos. Chem. Phys., 13, 8787–8796, https://doi.org/10.5194/acp-13-8787-2013, 2013b.
Ishidoya, S., Tsuboi, K., Matsueda, H., Murayama, S., Taguchi, S., Sawa, Y., Niwa, Y., Saito, K., Tsuji, K., Nishi, H., Y. Baba, Y., Takatsuji, S., Dehara, K., and Fujiwara, H.: New atmospheric O2/N2 ratio measurements over the western North Pacific using a cargo aircraft C-130H, SOLA, 10, 23–28, https://doi.org/10.2151/sola.2014-006, 2014.
Ishidoya, S., Sugawara, H., Terao, Y., Kaneyasu, N., Aoki, N., Tsuboi, K., and Kondo, H.: 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, Atmos. Chem. Phys., 20, 5293–5308, https://doi.org/10.5194/acp-20-5293-2020, 2020.
Ishidoya, S., Sugawara, S., Tohjima, Y., Goto, D., Ishijima, K., Niwa, Y., Aoki, N., and Murayama, S.: Secular change in atmospheric Ar/N2 and its implications for ocean heat uptake and Brewer–Dobson circulation, Atmos. Chem. Phys., 21, 1357–1373, https://doi.org/10.5194/acp-21-1357-2021, 2021.
Ishidoya, S., Tsuboi, K., Niwa, Y., Matsueda, H., Murayama, S., Ishijima, K., and Saito, K.: Spatiotemporal variations of the δ(O2/N2), CO2 and δ(APO) in the troposphere over the western North Pacific, Atmos. Chem. Phys., 22, 6953–6970, https://doi.org/10.5194/acp-22-6953-2022, 2022.
Ishidoya, S., Tsuboi, K., Kondo, H., Ishijima, K., Aoki, N., Matsueda, H., and Saito, K.: Measurement report: Method for evaluating CO2 emissions from a cement plant using atmospheric δ(
Joussaume, S. and Jouzel, J.: Paleoclimatic tracers: An investigation using an atmospheric general circulation model under ice age conditions 2. Water isotopes, J. Geophys. Res., 98, 2807–2830, 1993.
Jouzel, J., Russell, G. L., Suozzo, R. J., Koster, R. D., White, J. W. C., and Broecker, W. S.: Simulations of the HDO and H
Keeling, C. D., Piper, S. C., Bacastow, R. B., Wahlen, M., Whorf, T. P., Heimann, M., and Meijer, H. A.: Exchanges of atmospheric CO2 and 13CO2 with the terrestrial biosphere and oceans from 1978 to 2000, I. Global aspects, SIO Reference Series, No. 01-06, Scripps Institution of Oceanography, San Diego, 88 pp., https://scrippsco2.ucsd.edu/assets/publications/keeling_sio_ref_series_exchanges_of_co2_ref_no_01-06_2001.pdf (last access: 1 February 2025), 2001.
Keeling, R. and Manning, A.: Studies of Recent Changes in Atmospheric O2 Content, in: Treatise on Geochemistry, 2nd edn., Elsevier Inc., 5, 385–404, https://doi.org/10.1016/B978-0-08-095975-7.00420-4, 2014.
Keeling, R. F.: Development of an Interferometric Oxygen Analyzer for Precise Measurement of the Atmospheric O2 Mole Fraction, PhD thesis, Harvard University, Cambridge, 1988.
Keeling, R. F.: The atmospheric oxygen cycle: The oxygen isotopes of atmospheric CO2 and O2 and the N2/O2 ratio, Rev. Geophys., 33, 1253–1262, 1995.
Keeling, R. F., Blaine, T., Paplawsky, B., Katz, L., At- wood, C., and Brockwell, T.: Measurement of changes in atmospheric Ar/N2 ratio using a rapid-switching, single-capillary mass spectrometer system, Tellus B, 56, 322–338, https://doi.org/10.3402/tellusb.v56i4.16453, 2004.
Liu, J., Jiang, C., Wu, H., Guo, L., Zhang, H., and Zhao, Y.: Controls on leaf water hydrogen and oxygen isotopes: a local investigation across seasons and altitude, Hydrol. Earth Syst. Sci., 27, 599–612, https://doi.org/10.5194/hess-27-599-2023, 2023.
Luz, B. and Barkan, E.: The isotopic composition of atmospheric oxygen, Global Biogeochem. Cy., 25, GB3001, https://doi.org/10.1029/2010GB003883, 2011.
Luz, B., Barkan, E., Bender, M. L., Thiemens, M. H., and Boering, K. A.: Triple-isotope composition of atmospheric oxygen as a tracer of biosphere productivity, Nature, 400, 547–550, https://doi.org/10.1038/22987, 1999.
Madani, N., Parazoo, N. C., Kimball, J. S., Ballantyne, A. P., Reichle, R. H., Maneta, M., Saatchi, S., Palmer P. I., Liu, Z., and Tagesson, T.: Recent amplified global gross primary productivity due to temperature increase is offset by reduced productivity due to water constraints, AGU Advances, 2, e2020AV000180, https://doi.org/10.1029/2020AV000180, 2020.
Manning, A. C. and Keeling, R. F.: Global oceanic and terrestrial biospheric carbon sinks from the Scripps atmospheric oxygen flask sampling network, Tellus B, 58, 95–116, 2006.
Minejima, C., Kubo, M., Tohjima, Y., Yamagishi, H., Koyama, Y., Maksyutov, S., Kita, K., and Mukai, H.: Analysis of ΔO
Morita, N.: The increased density of air oxygen relative to water oxygen, J. Chem. Soc. Japan, 56, 1291, 1935.
Morgan, E. J., Manizza, M., Keeling, R. F., Resplandy, L., Mikaloff-Fletcher, S. E., Nevison, C. D., Jin, Y., Bent, J. D., Aumont, O., Doney, S. C., Dunne, J. P., John, J., Lima, I. D., Long, M. C., and Rodgers, K. B.: An atmospheric constraint on the seasonal air-sea exchange of oxygen and heat in the extratropics. J. Geophys. Res.-Oceans, 126, e2021JC017510. https://doi.org/10.1029/2021JC017510, 2021.
Murayama, S., Takamura, C., Yamamoto, S., Saigusa, N., Morimoto, S., Kondo, H., Nakazawa, T., Aoki, S., Usami, T., and M. Kondo, M.: Seasonal variations of atmospheric CO2, δ13C, and δ18O at a cool temperate deciduous forest in Japan: Influence of Asian monsoon, J. Geophys. Res., 115, D17304, https://doi.org/10.1029/2009JD013626, 2010.
Nevison, C. D., Keeling, R. F., Kahru, M., Manizza, M., Mitchell, B. G., and Cassar, N.: Estimating net community production in the Southern ocean based on atmospheric potential oxygen and satellite ocean color data, Global Biogeochem. Cy., 26, GB1020, https://doi.org/10.1029/2011GB004040, 2012.
Okazaki, A. and Yoshimura, K.: Development and evaluation of a system of proxy data assimilation for paleoclimate reconstruction, Clim. Past, 13, 379–393, https://doi.org/10.5194/cp-13-379-2017, 2017.
Okazaki, A. and Yoshimura, K.: Global evaluation of proxy system models for stable water isotopes with realistic atmospheric forcing, J. Geophys. Res.-Atmos., 124, 8972–8993. https://doi.org/10.1029/2018JD029463, 2019.
Olsen, M. A., Schoeberl, M. R., and Douglass, A. R.: Stratosphere-troposphere exchange of mass and ozone, J. Geophys. Res., 109, D24114, https://doi.org/10.1029/2004JD005186, 2004.
Peylin, P., Ciais, P., Denning, A. S., Tans, P. P., Berry, J. A., and White, J. W. C.: A 3-dimensional study of δ18O in atmospheric CO2: Contribution of different land ecosystems, Tellus B, 51, 642–667, 1999.
Pickers, P. A., Manning, A. C., Le Quéré, C., Forster, G. L., Luijkx, I. T., Gerbig, C., Fleming, L. S., and Sturges, W. T.: Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurements, Sci. Adv., 8, eabl9250, https://doi.org/10.1126/sciadv.abl9250, 2022.
Plavcová, L., Hronková, M., Šimková, M., Květoň , J., Vráblová, M., Kubásek, and Šantrůček, J.: Seasonal variation of δ18O and δ2H in leaf water of Fagus sylvatica L. and related water compartments, J. Plant Physiol., 227, 56–65, 2018.
Rozanski, K., Araguás-Araguás, L., and Gonfiantini, R.: Relation between long-term trends of oxygen-18 isotope composition of precipitation and climate, Science, 258, 981–985, https://doi.org/10.1126/science.258.5084.981, 1992.
Rubino, M., Etheridge, D., Thornton, D., Allison, C., Francey, R., Langenfelds, R., Steele, P., Trudinger, C., Spencer, D., Curran, M., Van Ommen, T., and Smith, A.: Law Dome Ice Core 2000-Year CO2, CH4, N2O and δ13C-CO2. v2. CSIRO, Data Collection, https://doi.org/10.25919/5bfe29ff807fb, 2019.
Schumacher, M., Werner, R. A., Meijer, H. A. J., Jansen, H. G., Brand, W. A., Geilmann, H., and Neubert, R. E. M.: Oxygen isotopic signature of CO2 from combustion processes, Atmos. Chem. Phys., 11, 1473–1490, https://doi.org/10.5194/acp-11-1473-2011, 2011.
Seibt, U., Berry, J. A., Battle, M., and Severinghaus, J. P.: Exploring potential anthropogenic changes in the Dole-Morita effect, abstract of the 7th International CO2 Conference, https://gml.noaa.gov/icdc7/proceedings/abstracts/seibtFF351.pdf (last access: 1 February 2025), 2005.
Sellers, P., Randall, D. A., Collatz, G. J., Berry, J. A., Field, C. B., Dazlich, D. A., Zhang, C., Collelo, G. D., and Bounoua, L.: A Revised Land Surface Parameterization (SiB2) for Atmospheric GCMS. Part I: Model Formulation, J. Climate, 9, 676–705, 1996.
Severinghaus, J.: Studies of the terrestrial O2 and carbon cycles in sand dune gases and in biosphere 2, PhD thesis, Columbia University, New York, 1995.
Severinghaus, J. P., Beaudette, R., Headly, M. A., Taylor, K., and Brook, E. J.: Oxygen-18 of O2 records the impact of abrupt climate change on the terrestrial biosphere, Science, 324, 1432–1434, https://doi.org/10.1126/Science.1169473, 2009.
Sturm, P., Leuenberger, M., Valentino, F. L., Lehmann, B., and Ihly, B.: Measurements of CO2, its stable isotopes, O2/N2, and 222Rn at Bern, Switzerland, Atmos. Chem. Phys., 6, 1991–2004, https://doi.org/10.5194/acp-6-1991-2006, 2006.
Sugawara, H., Ishidoya, S., Terao, Y., Takane, Y., Kikegawa, Y., and Nakajima, K.: Anthropogenic CO2 emissions changes in an urban area of Tokyo, Japan, due to the COVID-19 pandemic: A case study during the state of emergency in April–May 2020, Geophys. Res. Lett., 48, e2021GL092600, https://doi.org/10.1029/2021GL092600, 2021.
Sugawara, S., Ishidoya, S., Aoki, S., Morimoto, S., Nakazawa, T., Toyoda, S., Inai, Y., Hasebe, F., Ikeda, C., Honda, H., Goto, D., and Putri, F. A.: Age and gravitational separation of the stratospheric air over Indonesia, Atmos. Chem. Phys., 18, 1819–1833, https://doi.org/10.5194/acp-18-1819-2018, 2018.
Thiemens, M. H.: Mass-independent isotope effects in planetary atmospheres and the early solar system, Science, 283, 341–345, https://doi.org/10.1126/science.283.5400.341, 1999.
Tohjima, Y., Mukai, H., Machida, T., Hoshina, Y., and Nakaoka, S.-I.: Global carbon budgets estimated from atmospheric O2/N2 and CO2 observations in the western Pacific region over a 15-year period, Atmos. Chem. Phys., 19, 9269–9285, https://doi.org/10.5194/acp-19-9269-2019, 2019.
Watanabe, M., Suzuki, T., O'ishi, R., Komura, Y., Watanabe, S., Emori, S., Takemura, T., Chikira, M., Ogura, T., Sekiguchi, M., Takata, K., Yamazaki, D., Yokohata, T., Nozawa, T., Hasumi, H., Tatebe, H., and Kimoto, M.: Improve climate simulated by MIROC5: Mean states, variability, and climate sensitivity, J. Climate, 23, 6312–6335, 2010.
Weiss, R. F.: The solubility of nitrogen, oxygen and argon in water and seawater, Deep-Sea Res., 17, 721–735, 1970.
Welp, L. R., Lee, X., Kim, K., Griffis, T. J., Billmark, K. A., and Baker, J. M.: δ18O of water vapour, evapotranspiration and the sites of leaf water evaporation in a soybean canopy. Plant. Cell Environ., 31, 1214–1228, 2008.
Welp, L. R., Keeling, R. F., Meijer, H. A. J., Bollenbacher, A. F., Piper, S. C., Yoshimura, K., Francey, R. J., Allison, C. E., and Wahlen, M.: Interannual variability in the oxygen isotopes of atmospheric CO2 driven by El Niño, Nature, 477, 579–582, https://doi.org/10.1038/nature10421, 2011.
West, J. B., Sobek, A., and Ehleringer, J. R.: A simplified GIS approach to modeling global leaf water isoscapes, PLoS ONE, 3, e2447, https://doi.org/10.1371/journal.pone.0002447, 2008.
Yoshimura, K., Miyazaki, S., Kanae, S., and Oki, T.: Iso-MATSIRO, a land surface model that incorporates stable water isotopes, Glob. Planet. Change, 51, 90–107, 2006.
Zheng, Y., Shen, R., Wang, Y., Li, X., Liu, S., Liang, S., Chen, J. M., Ju, W., Zhang, L., and Yuan, W.: Improved estimate of global gross primary production for reproducing its long-term variation, 1982–2017, Earth Syst. Sci. Data, 12, 2725–2746, https://doi.org/10.5194/essd-12-2725-2020, 2020.
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.
The 18O/16O ratio of atmospheric oxygen, δatm(18O), is higher than that of ocean water due to...
Altmetrics
Final-revised paper
Preprint