Review of Tropospheric Bomb ¹⁴C Data for Carbon Cycle Modeling and Age Calibration Purposes

Abstract

Comprehensive published radiocarbon data from selected atmospheric records, tree rings, and recent organic matter were analyzed and grouped into 4 different zones (three for the Northern Hemisphere and one for the whole Southern Hemisphere). These 14C data for the summer season of each hemisphere were employed to construct zonal, hemispheric, and global data sets for use in regional and global carbon model calculations including calibrating and comparing carbon cycle models. In addition, extended monthly atmospheric 14C data sets for 4 different zones were compiled for age calibration purposes. This is the first time these data sets were constructed to facilitate the dating of recent organic material using the bomb 14C curves. The distribution of bomb 14C reflects the major zones of atmospheric circulation.

Carbon Isotopes in Tree Rings: Climate and the Suess Effect Interferences in the Last 400 Years

“…The trees are sensitive bioindicators of changes in CO 2 emitted into the atmosphere, and 14 C measurements in tree rings may trace this in industrial areas (Rakowski et al 2001(Rakowski et al , 2005(Rakowski et al , 2006. Changes in ∆ 14 C caused by the emission of CO 2 into the atmosphere (the so-called Suess effect; Suess 1955) on the background, which is influenced by the effects of natural change and nuclear weapon tests, have been observed (Stuiver et al 1998;Hua and Barbetti 2004;see Figures 3 and 4).…”

“…where ∆ 14 C BG and ∆ 14 C (Stuiver and Polach 1977) are values for clean air (without local Suess effect; Hua and Barbetti 2004) and in the local area, respectively. Figure 2 Regional (left scale) and global (right scale) emission of CO 2 into the atmosphere from the fossil fuel combustion in thousands of metric tons of carbon (according to Marland et al 2005).…”

“…The records of δ 13 C in α-cellulose extracted from pines growing in northeastern and southern Poland and records of δ 13 C in α-cellulose from oak latewood from the southern part of Poland over the last 400 yr are presented along with the climate change indicators and the variation of atmospheric ∆ 14 C values in the Northern Hemisphere (NH) zone 1 (Hua and Barbetti 2004).…”

Hydrological control of the dead carbon fraction in a Holocene tropical speleothem

“…is the atmospheric a 14 C initial activity, derived from the SHCal04 calibration curve for the period before 1950 A.D., from tree-ring data (Hua et al, 2000(Hua et al, , 2003 for the interval between 1950 and 1954 A.D., and from the updated SH zone (Hua and Barbetti, 2004) for the period from 1955 A.D. onwards. To calculate the DCF and associated 1s error, we first calculated the a 14 C atm.init.…”

Applications of Radiocarbon Dating Method

“…Anthropogenic changes in the atmospheric 14 C content caused by fossil fuel combustion and the addition of " 14 C-free" carbon (Suess effect), as well as the nuclear tests ( 14 C bomb peak), greatly affected the 14 C dating of the last 150 yr. Measurements of the atmospheric 14 C content have been performed during the last 50 yr (Hua and Barbetti 2004;Levin and Kromer 2004). Stations located around the world collect air samples from pristine and urban areas.…”