Mass balance equations can be used to quantify the level of fossil carbon dioxide (CO<sub>2</sub>)<sub>ff</sub> at a given site by using samples of tree leaves or tree rings. These sites are of...Mass balance equations can be used to quantify the level of fossil carbon dioxide (CO<sub>2</sub>)<sub>ff</sub> at a given site by using samples of tree leaves or tree rings. These sites are often densely populated and highly industrialized areas. In this case, in addition to the natural carbon dioxide level of the site, there are several other components that are added to it. The approaches we propose in this paper are based on the isotopic fractionation of carbon and the laws of matter conservation. Mathematical equations are derived from this and we propose approaches to establish them. Our method has allowed us to come to the conclusion of the relationship that is already found in literature. But we term this relationship in another way by introducing the fraction of carbon modern F and the proportion of CO<sub>2</sub> derived from fossil fuels, which will be noted (S)<sub>ff</sub> for the following. As an indicator of the Suess Effect, we have calculated these values in our different sites. Wooded areas sites which are located in urban areas have higher value of proportion of fossil fuel <span style="white-space:normal;">(S)</span><sub style="white-space:normal;">ff</sub> .展开更多
文摘Mass balance equations can be used to quantify the level of fossil carbon dioxide (CO<sub>2</sub>)<sub>ff</sub> at a given site by using samples of tree leaves or tree rings. These sites are often densely populated and highly industrialized areas. In this case, in addition to the natural carbon dioxide level of the site, there are several other components that are added to it. The approaches we propose in this paper are based on the isotopic fractionation of carbon and the laws of matter conservation. Mathematical equations are derived from this and we propose approaches to establish them. Our method has allowed us to come to the conclusion of the relationship that is already found in literature. But we term this relationship in another way by introducing the fraction of carbon modern F and the proportion of CO<sub>2</sub> derived from fossil fuels, which will be noted (S)<sub>ff</sub> for the following. As an indicator of the Suess Effect, we have calculated these values in our different sites. Wooded areas sites which are located in urban areas have higher value of proportion of fossil fuel <span style="white-space:normal;">(S)</span><sub style="white-space:normal;">ff</sub> .