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Measurement of 14C Concentrations of Stratospheric CO2 by Accelerator Mass Spectrometry

Published online by Cambridge University Press:  18 July 2016

Toshio Nakamura ,
Takakiyo Nakazawa ,
Nobuyuki Nakai ,
Hiroyuki Kitagawa ,
Hideyuki Honda ,
Tomizo Itoh ,
Toshinobu Machida  and
Eiji Matsumoto
Toshio Nakamura
Affiliation:
Dating and Materials Research Center, Nagoya University, Nagoya 464-01 Japan
Takakiyo Nakazawa
Affiliation:
Faculty of Science, Tohoku University, Sendai 980 Japan
Nobuyuki Nakai
Affiliation:
Department of Earth Sciences, Nagoya University
Hiroyuki Kitagawa
Affiliation:
Water Research Institute, Nagoya University
Hideyuki Honda
Affiliation:
Institute of Space and Astronautical Science, Sagamihara 229 Japan
Tomizo Itoh
Affiliation:
Institute of Space and Astronautical Science, Sagamihara 229 Japan
Toshinobu Machida
Affiliation:
Faculty of Science, Tohoku University, Sendai 980 Japan
Eiji Matsumoto
Affiliation:
Water Research Institute, Nagoya University
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Abstract

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In order to measure the concentrations of anthropogenically influenced gases in the stratosphere, we have collected air samples from the lower stratosphere since 1985, by a balloon-borne cryogenic sampling method, developed at the Institute of Space and Astronautical Science (ISAS). Air samples of ≃16 liters at STP were collected in the stratosphere at altitudes from 18.6 to 30.4 km, over the northeastern part of Japan (39.5°N, 139–142°E), on 1 September 1989. We conducted 14C analyses to study the vertical and horizontal air-mass movement in the stratosphere, and to investigate the air transport mechanism between troposphere and stratosphere. Carbon dioxide (containing a few mg carbon) was separated cryogenically from the air samples, and the 14C concentration of the CO2 was measured by a Tandetron accelerator mass spectrometer, using Fe-graphite targets prepared by reducing CO2 on Fe-powder with hydrogen in a Vycor tube at 650°. The 14C concentrations, expressed as Δ14C, of CO2 were 267–309‰ at altitudes of 21–30 km, and 134‰ at 19–20 km. The Δ14C values at 21–30 km were higher than those of the current tropospheric CO2, of around 80–200‰. The observed 14C concentrations, higher in the stratosphere than the troposphere, seem to be explained by large bomb-produced 14C inventories and/or high 14C production by cosmic rays, as well as weak vertical mixing of air masses in the stratosphere.

Information

Type
III. Global 14C Production and Variation
Information
Radiocarbon , Volume 34 , Issue 3: Proceedings of the 14th International Radiocarbon Conference , 1992 , pp. 745 - 752
Copyright
Copyright © The American Journal of Science 

References

Cain, W. F. and Suess, H. E. 1976 Carbon 14 in tree rings. Journal of Geophysical Research 81: 3688–3694.Google Scholar
Gamo, T. and Horibe, Y. 1985 Gas chromatographic separation of CO2 and N2O for measurements of δ13C in atmospheric CO2 . Geochemical Journal 19: 171–174.CrossRefGoogle Scholar
Gamo, T., Tsutsumi, M., Sakai, H., Nakazawa, T., Tanaka, M., Honda, H., Kubo, H. and Itoh, T. 1989 Carbon and oxygen isotopic ratios of carbon dioxide of a stratospheric profile over Japan. Tellus 41B: 127–133.Google Scholar
Hagemann, F., Gray, J. J., Machta, L. and Turkevich, A. 1959 Stratospheric carbon-14, carbon dioxide, and tritium. Science 130: 542–552.Google Scholar
Honda, H. 1990 Balloon-borne cryogenic whole air sampling system. ISAS Research Note 433: 39 p.Google Scholar
Honda, H., Minagawa, H. and Itoh, T. 1987 Development of cryogenic, whole air sampling system for stratospheric trace gas studies. Uchuken Hokoku Special Issue 20: 73–107 (in Japanese).Google Scholar
Itoh, T., Honda, H., Tominaga, T., Makide, Y., Yamaki, R., Nakazawa, T., Hashida, H., Sakai, H., Tsutsumi, M. and Gamo, T. 1989 The vertical distribution of stratospheric trace gas mixing ratios over Japan. Uchuken Hokoku Special Issue 24: 49–61 (in Japanese).Google Scholar
Junge, C. A. 1963 Air Chemistry and Radioactivity. International Geophysics Series. New York, Academic Press: 382 p.Google Scholar
Kitagawa, H., Masuzawa, T., Matsumoto, E., Yamaguchi, K. and Nakamura, T. 1991 A preparation method of graphite target by reduction of CO2 with H2 for AMS 14C measurement. Summaries of Research Using AMS at Nagoya University II: 113–121 (in Japanese).Google Scholar
Makide, Y., Yokohata, A., Tominaga, T., Honda, H., Kubo, H. and Itoh, T. 1987 Vertical profiles of CCl3F, CCl2F2, and CH4 in the stratosphere and troposphere over Japan as observed by balloon grab-sampling and gas-chromatographic analysis. Bulletin of the Chemical Society of Japan 60: 1540–1542.Google Scholar
Nakai, N., Nakamura, T., Kimura, M., Sakase, T., Sato, S. and Sakai, A. 1984 Accelerator mass spectrometry of 14C at Nagoya University. In Wölfli, W., Polach, H. A. and Anderson, H. H., eds., Proceedings of the 3rd International Symposium on Accelerator Mass Spectrometry. Nuclear Instruments and Methods 233(B5): 171–174.CrossRefGoogle Scholar
Nakamura, T., Nakai, N. and Furukawa, M. 1990 Techniques of tandem accelerator mass spectrometry and their applications to 14C measurements. In Kaneko, Y., ed., Proceedings of the 2nd International Symposium on Advanced Nuclear Research-Evolution by Accelerators. 596–601.Google Scholar
Nakamura, T., Nakai, N. and Ohishi, S. 1987 Applications of environmental 14C measured by AMS as a carbon tracer. In Gove, H. E., Litherland, A. E. and Elmore, D., eds., Proceedings of the 4th International Symposium on Accelerator Mass Spectrometry. Nuclear Instruments and Methods B29: 355–360.CrossRefGoogle Scholar
Nakamura, T., Nakai, N., Sakase, T., Kimura, M., Ohishi, S., Taniguchi, M. and Yoshioka, S. 1985 Direct detection of radiocarbon using accelerator techniques and its application to age measurement. Japanese Journal of Applied Physics 24: 1716–1723.Google Scholar
Nakazawa, T., Miyashita, K., Aoki, S. and Tanaka, M. 1991 Temporal and spatial variations of upper tropospheric and lower stratospheric carbon dioxide. Tellus 43B: 106–117.Google Scholar
Nydal, R. 1968 Further investigation on the transfer of radiocarbon in nature. Journal of Geophysical Research 73: 3617–3635.Google Scholar
Nydal, R. and Løvseth, K. 1983 Tracing bomb 14C in the atmosphere. Journal of Geophysical Research 88: 3621–3642.CrossRefGoogle Scholar
O'Brien, K. 1979 Secular variations in the production of cosmogenic isotopes in the Earth's atmosphere. Journal of Geophysical Research 84: 423–431.Google Scholar
Rafter, T. A. and Fergusson, G. J. 1957 Atom bomb effect – recent increase of carbon-14 content of the atmosphere and biosphere. Science 126: 566–578.Google Scholar
Tanaka, M., Nakazawa, T. and Aoki, S. 1983 Concentration of atmospheric carbon dioxide over Japan. Journal of Geophysical Research 88: 1338–1344.Google Scholar
Tanaka, M., Nakazawa, T. and Aoki, S. 1987 Time and space variations of tropospheric carbon dioxide over Japan. Tellus 39B: 3–12.Google Scholar
Tanaka, M., Nakazawa, T., Shiobara, M., Ohshima, H., Aoki, S., Kawaguchi, S., Yamanouchi, T., Makino, Y. and Murayama, H. 1987 Variations of atmospheric carbon dioxide concentration at Syowa Station (69°00'S, 39°35'E), Antarctica. Tellus 39B: 72–79.CrossRefGoogle Scholar
Vogel, J. S., Nelson, D. E. and Southon, J. R. 1987 14C background levels in an accelerator mass spectrometry system. Radiocarbon 29(3): 323–333.Google Scholar