Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-05-22T13:25:14.979Z Has data issue: false hasContentIssue false

Variation of Concentration, 14C Activity and 13C/12C Ratios of CO2 in Air Samples from Kitt Peak, Arizona

Published online by Cambridge University Press:  18 July 2016

S W Leavitt
Affiliation:
Department of Geology, University of Wisconsin-Parkside Kenosha, Wisconsin 53141
Austin Long
Affiliation:
Department of Geology, University of Wisconsin-Parkside Kenosha, Wisconsin 53141
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Air was sampled with 5L flasks at Kitt Peak (2100m elev) from 1983 through 1984 at approximately monthly intervals, occasionally supplemented with air samples from urban Tucson ca 75km away (760m elev). The Kitt Peak CO2 concentrations, represented by a yield measurement, fluctuated ca 25% over the monitoring period. The δ13C values (uncorrected for N2O) varied from ca −7.6 to −9.0, with high values (and low CO2 yields) in the late summer consistent with hemispheric seasonal biosphere effects. Tucson air has lower δ13C values and possibly greater CO2 yield suggesting a local fossil-fuel effect. 14C activity of four Kitt Peak samples range from 1.158±.007 to 1.223±.008 as uncorrected fraction of modern, below free air activity of ca 1.250 for 1984 even after correcting for fractionation. The slightly low 14C activity and δ13C values suggest the Kitt Peak air is not quite 100% clean and there may be a local/regional fossil-fuel contribution, but CO2 concentrations are similar to background atmospheric values.

Type
II. Carbon Cycle in the Environment
Copyright
Copyright © The American Journal of Science 

References

Craig, H, 1957, Isotopic standards for carbon and oxygen and correction factors for mass-spectrometric analysis of CO2 : Geochim et Cosmochim Acta, v 12, p 133149.CrossRefGoogle Scholar
Florkowski, T and Kuc, T, 1979, Carbon isotopes and sulphur content as indicators of atmospheric pollution from burning fossil fuels: Environment Internatl, v 2, p 431435.Google Scholar
Harkness, DD, Harrison, AF and Bacon, PJ, 1986, The temporal distribution of “bomb” 14C in a forest soil, in Stuiver, M and Kra, RS, eds, Internatl 14C conf, 12th, Proc: Radiocarbon, v 28, no.2A, p 328337.Google Scholar
Jull, AJT, Donahue, DJ, Hatheway, AL, Linick, TW and Toolin, LJ, 1986, Production of graphite targets by deposition from CO/H2 for precision accelerator 14C measurement, in Stuiver, M and Kra, RS, eds, Internatl 14C conf, 12th, Proc: Radiocarbon, v 28, no. 2A p 191197.Google Scholar
Keeling, CD, Mook, WG and Tans, PP, 1979, Recent trends in the 13C/12C ratio of atmospheric carbon dioxide: Nature, v 277, p 121123.Google Scholar
Klouda, GA, Currie, LA, Donahue, DJ, Jull, AJT and Taylor, MH, 1986, Urban atmospheric 14CO and 14CH4 measurements by accelerator mass spectrometry, in Stuiver, M and Kra, RS, eds, Internatl 14C conf, 12th, Proc: Radiocarbon, v 28, no. 2A, p 625633.Google Scholar
Kuc, T, 1986, Carbon isotopes in atmospheric CO2 of the Krakow region: a two-year record, in Stuiver, M and Kra, RS, eds, Internatl 14C conf, 12th, Proc: Radiocarbon, v 28, no.2A, p 649654.Google Scholar
Mook, WG, Carter, AF and Keeling, CD, 1983, Seasonal, latitudinal, and secular variations in the abundance and isotopic ratios of atmospheric carbon dioxide 1: results from land stations: Jour Geophys Research, v 88, p 1091510933.Google Scholar
Vogel, JC and Uhlitzsch, I, 1975, Carbon-14 as an indicator of CO2 pollution in cities, in Isotope ratios as pollutant source and behavior indicators: Vienna, IAEA, p 143152.Google Scholar