1. Measurements of <14>^C concentrations of stratosphric CO_2 using a tandetron accelerator mass spectrometer
- Author
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Nakamura, Toshio, Nakazawa, Takakiyo, Machida, Toshinobu, Nakai, N., Kitagawa, H., Matsumoto, E., Hond, H., and Itoh, T.
- Abstract
Air samples of about 16 liter in STP were collected from the stratosphere at altitutes of 18,20,21,23,24,26,27,29,30km, by a cryogenic-sampling apparatus with a liquid helium cooling system, on 1 September 1989,off Sanriku-Shore, Miyagi Prefecture, Northeastern part of Japan. The sampling apparatus was flown up to the stratosphere by a balloon at the Sanriku balloon station (39.2N, 141.8W) of the Institute of Space and Astronautical Scinece. Carbon dioxide of a few mg of carbon was separated from air samples with a cryogenic method at Tohoku University, and ^C concentrations of the CO_2 were measured with a Tandetron accelerator mass spectrometer at Nagoya University for a Fe-graphite target prepares by reducing CO_2 on Fe-powder with hydrogen in a Vycol tube at 500C. The ^C concentrations, Δ^C, of CO_2 were 270-310%. at altitudes of 21-30km, and 130%. at 18-20km. The Δ^C values at 21-30km were higher than the Δ^C of the current tropospheric CO_2 of around 100-150%.
- Published
- 1992