Advances in Earth Science
• Articles •
Chen Zhongxiao, Zhao Qi
Chen Zhongxiao, Zhao Qi. δ
13C Methods and Its Progress in the Study of Global Carbon Cycle[J]. Advances in Earth Science, 2011, 26(11): 1225-1233.
With the development of analytical technique, δ13C observations have been paid more attentions in the study of global carbon cycle. Based on the discussion the fundamental concepts of δ13C in the global carbon cycle, such as δ13C Suess Effect, observed δ13C ranges of various carbon reservoirs and fractionation between them, this article introduces the analytical methods in applying δ13C to distinguish carbon source and sink by combining with current observational facts. The roles of δ13C in the study of seasonal and interannual variations of atmospheric CO2 are discussed based on the facts that the δ13C from ocean is similar to that of atmosphere but that from terrestrial biosphere is much smaller than that of atmosphere. The various Keeling Plot approaches are introduced to show the achievements in analyzing the background characteristics of atmospheric CO2 and its applicability is also discussed. The mass balance methods using observed atmospheric δ13C are analyzed to represent how to only use atmospheric δ13C data studying the missing carbon problems. The various δ13C inventory techniques in the assessment of global carbon cycle, particularly oceanic uptake rate, are analyzed to point out their features and shortages, and these techniques offer no model approaches to investigate the global carbon cycle. We stress that the uncertainties between inventory approaches are mainly from the observational errors, not from the techniques. Finally, the prospects of δ13C research in the global carbon cycle for both observational and theoretical fields are also discussed, especially the model based simulations.