Fractionation of ^(14)N^(15)N^(16)O and ^(15)N^(14)N^(16)O during photolysis at 213 nm
Abstract
Motivated by Yung and Miller's [1997] suggestion that N2O is isotopically fractionated during UV photolysis in the stratosphere, we have studied the photolysis rates of the ^(14)N^(15)N^(16)O and ^(15)N^(14)N^(16)O structural isotopomers. In this study, we follow the concentrations of these compounds with FTIR spectroscopy during photolysis at 213 nm. When fitted to a Rayleigh fractionation model, the observations yield single‐stage enrichment factors of ϵ(^(14)N^(15)N^(16)O / ^(14)N^(14)N^(16)O) = −73 ± 5 per mil and ϵ(^(15)N^(14)N^(16)O / ^(14)N^(14)N^(16)O) = −41 ± 10 per mil. As predicted by Yung and Miller [1997], the photolysis rate of ^(15)N^(14)N^(16)O is faster than ^(14)N^(15)N^(16)O at this wavelength. The magnitude of the observed fractionation, however, is significantly larger than predicted.
Additional Information
© 2000 American Geophysical Union. Received 14 November 1999; accepted 29 February 2000. We would like to thank the NSF MRI program for the photolysis laser, CASIX Inc. for the BBO crystals and the Dreyfus Foundation for the FTIR spectrometer used in this study. Vincent Wu acknowledges financial support from an anonymous donor through a Caltech Summer Undergraduate Research Fellowship.Attached Files
Published - 1999GL011236.pdf
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- Eprint ID
- 34109
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- CaltechAUTHORS:20120914-144208949
- Caltech Summer Undergraduate Research Fellowship (SURF)
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2012-09-14Created from EPrint's datestamp field
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2021-11-09Created from EPrint's last_modified field
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- Division of Geological and Planetary Sciences