Hostname: page-component-76fb5796d-wq484 Total loading time: 0 Render date: 2024-04-25T17:37:33.842Z Has data issue: false hasContentIssue false

Anthropogenic CO2 in the Dakar (Senegal) Urban Area Deduced from 14C Concentration in Tree Leaves

Published online by Cambridge University Press:  14 June 2017

Maurice Ndeye*
Affiliation:
Laboratoire Carbone 14, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar, Dakar, Senegal
Matar Sène
Affiliation:
Faculté des Sciences et Techniques, Université Cheikh Anta Diop de Dakar, Dakar, Senegal
Doudou Diop
Affiliation:
Laboratoire de Botanique, Institut Fondamental d’Afrique Noire (IFAN), Université Cheikh Anta Diop de Dakar, Dakar, Senegal
Jean-François Saliège
Affiliation:
Laboratoire d’Océanogrphie (LOCEAN), Université Pierre et Marie Curie, Paris VI, France (deceased 1 June 2012)
*
*Corresponding author. Email: maurice.ndeye@ucad.edu.sn.

Abstract

Radiocarbon (14C) in atmospheric CO2 for the Dakar (Senegal) urban area was measured using tree leaves collected by botanists from 1900 to 2003. The aim of our study was to compare the local Suess effect in Dakar to the global one during the 20th century. The ∆14C of atmospheric CO2 in this region decreased from 1900 to 1958 during the pre-bomb era (–2±5‰ to –22±4‰). From 1958 to 1964, nuclear bomb tests injected a large amount of artificial 14C into the atmosphere, reflected in the rise of ∆14C values. In the Dakar region, the atmospheric ∆14C reached 773±8‰ in 1964, but subsequently decreased to 80±5‰ by 2003, which is consistent with the global exponential decreasing trend. The ∆14C record presented here remains slightly lower than the global record. This result is attributed to the input of anthropogenic fossil carbon into the atmosphere. The amount of carbon input can be evaluated by comparing urban areas to those of clean air sites. The calculation of anthropogenic fossil carbon is deduced from a simple mathematical model.

Type
Studies of Calibration, Environment, and Soils
Copyright
© 2017 by the Arizona Board of Regents on behalf of the University of Arizona 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

Selected Papers from the 2015 Radiocarbon Conference, Dakar, Senegal, 16–20 November 2015

References

REFERENCES

Dieng, M. 2007. Dakar, la ‘fourmilière humaine’ auditée. 25 May 2007. Sud Quotidien. http://xfru.it/9eiTIR. In French.Google Scholar
Druffel, EM, Suess, HE. 1983. On the radiocarbon record in banded coral: exchange parameters and net transport of 14CO2 between atmosphere and surface ocean. Journal of Geophysical Research 88(C2):12711280.Google Scholar
Globalview-CO2. 2003. Cooperative atmospheric data intregation project—carbon dioxide. Boulder, CO: NOAACMDL. ftp.cmdl.noaa.gov.path:ccg/co2/globalview.Google Scholar
Houtermans, JC, Suess, HE, Oeschger, H. 1973. Reservoir models and production rate variations of natural radiocarbon. Geophysics Research 78:18971908.Google Scholar
Hua, Q, Barbetti, M. 2004. Review of tropospheric bomb 14C data for carbon cycle modeling and age calibration purposes. Radiocarbon 46(3):12731298.Google Scholar
Hua, Q, Barbetti, M, Rakowski, A. 2013. Atmospheric radiocarbon for the period 1950–2010. Radiocarbon 55(4):20592072.Google Scholar
Jull, AJT, Burr, GS, Beck, JW, Hodgins, GWL, Biddulph, DL, Gann, J, Hatheway, AL, Lange, TE, Lifton, NA. 2006. Application of accelerator mass spectrometry to environmental and paleoclimate studies at the University of Arizona. In: Povinec P, Sanchez-Cabrera J-A, editors. Radionuclides in the Environment. Amsterdam: Elsevier. p 323.Google Scholar
Levin, I, Kromer, B. 1997. Twenty years of atmospheric 14CO2 observations at Schauinsland station, Germany. Radiocarbon 39(2):205218.Google Scholar
Levin, I, Kromer, B. 2004. The tropospheric 14CO2 level in mid-latitudes of the Northern Hemisphere (1959–2003). Radiocarbon 46(3):12611272.Google Scholar
Levin, I, Kromer, B, Schmidt, M, Sartorius, H. 2003. A novel approach for independent budgeting of fossil fuel CO2 over Europe by 14CO2 observation. Geophysical Research Letters 30(23):2194.Google Scholar
Levin, I, Hamer, S, Kromer, B, Meinhardt, F. 2008. Radiocarbon observations in atmospheric CO2 over Europe using Jungfraujoch observations as background. Science of the Total Environment 391(2–3):211216.Google Scholar
Li, M-R, Wedin, DA, Tieszen, LL. 1999. C3 and C4 photosynthesis in Cyperus (Cyperaceae) in temperate eastern North America. Canadian Journal of Botany 77:209218.Google Scholar
Nydal, R, Lovesth, K. 1983. Tracing bomb 14C in the atmosphere, 1963–1980. Journal of Geophysical Research 88:36213642.Google Scholar
Nydal, R, Lovseth, K. 1996. Carbon-14 measurements in atmospheric CO2 from Northern and Southern Hemisphere sites, 1962–1993. ORNL/CDIAC-93, NDP-057. Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory. doi: 10.3334/CDIAC/atg.ndp057. 67 p.Google Scholar
Nydal, R, Lovesth, K, Guillicksen, S. 1979. A survey of radiocarbon variation in nature since the test band treat. In: Berger R, Suess HE, editors. Radiocarbon Dating. Berkeley: University of California Press. p 313323.Google Scholar
Oeschger, H, Siegenthaler, U, Schotter, U, Gugelman, A. 1975. A box diffusion model to study the carbon dioxide exchange in nature. Tellus 27(2):168192.Google Scholar
Rakowski, A, Nakamura, T, Pazdur, A. 2008. Variations of anthropogenic CO2 in urban area deduced by radiocarbon concentration in modern tree rings. Journal of Environmental Radioactivity 99:15581565.Google Scholar
Stuiver, M, Polach, H. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355363.Google Scholar
Suess, HE. 1955. Radiocarbon concentration in modern wood. Science 122:415.Google Scholar
Takahashi, H, Konohira, E, Hiyama, T, Minami, M, Nakamura, T, Yoshida, N. 2002. Diurnal variation of CO2 concentration, Δ14C and δ13C in an urban forest: estimate of the anthropogenic and biogenic CO2 contributions. Tellus B 54:97109.Google Scholar