ANTHROPOGENIC CO2 IN THE DAKAR (SENEGAL) URBAN AREA DEDUCED FROM C-14 CONCENTRATION IN TREE LEAVES

作者：Ndeye Maurice^*; Sene Matar; Diop Doudou; Saliege Jean Francois

来源：Radiocarbon, 2017, 59(3): 1009-1019.

DOI：10.1017/RDC.2017.48

• anthropogenic CO2
• fossil fuel
• radiocarbon
• Suess effect
• tree leaves

Radiocarbon (C-14) 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. Delta C-14 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 Delta C-14 values. In the Dakar region, the atmospheric Delta C-14 reached 773 +/- 8% in 1964, but subsequently decreased to 80 +/- 5% by 2003, which is consistent with the global exponential decreasing trend. The Delta C-14 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.

• 出版日期2017-6