Oxygen isotope anomaly in tropospheric CO_2 and implications for CO_2 residence time in the atmosphere and gross primary productivity
Abstract
The abundance variations of near surface atmospheric CO2isotopologues (primarily ^(16)O^(12)C^(16)O, ^(16)O^(13)C^(16)O, ^(17)O^(12)C^(16)O, and ^(18)O^(12)C^(16)O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, and stratospheric photochemistry. Oxygen isotopes, in particular, are affected by the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO_2 biogeochemical cycles, Δ^(17)O (=ln(1 + δ^(17)O) − 0.516 × ln(1 + δ^(18)O)) provides an alternative constraint on the strengths of the associated cycles involving CO_2. Here, we analyze Δ^(17)O data from four places (Taipei, Taiwan; South China Sea; La Jolla, United States; Jerusalem, Israel) in the northern hemisphere (with a total of 455 measurements) and find a rather narrow range (0.326 ± 0.005‰). A conservative estimate places a lower limit of 345 ± 70 PgC year^(−1) on the cycling flux between the terrestrial biosphere and atmosphere and infers a residence time of CO_2 of 1.9 ± 0.3 years (upper limit) in the atmosphere. A Monte Carlo simulation that takes various plant uptake scenarios into account yields a terrestrial gross primary productivity of 120 ± 30 PgC year^(−1) and soil invasion of 110 ± 30 PgC year^(−1), providing a quantitative assessment utilizing the oxygen isotope anomaly for quantifying CO_2 cycling.
Additional Information
© 2017 the Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received: 19 April 2017; Accepted: 15 September 2017; Published online: 13 October 2017. Special thank is due Chung-Ho Wang and Institute of Earth Sciences for providing lab space to accommodate our instruments, Chien-Chang Yen for discussion on error analysis, and S. K. Bhattacharya and Yuk Yung for helpful discussion. This work was supported in part by a MOST grant 105–2111-M-001-006-MY3 to Academia Sinica. Contributions: M.C.L. analysed the data and wrote the paper. S.M., A.H.L., and S.N. collected samples and performed analyses. M.H.T. provided calibrations. All authors discussed the results and commented on the manuscript. The authors declare that they have no competing interests.Attached Files
Published - s41598-017-12774-w.pdf
Supplemental Material - 41598_2017_12774_MOESM1_ESM.pdf
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Additional details
- PMCID
- PMC5640618
- Eprint ID
- 82566
- Resolver ID
- CaltechAUTHORS:20171023-080641976
- Ministry of Science and Technology (Taipei)
- 105–2111-M-001-006-MY3
- Created
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2017-10-24Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field