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23 paź 2020 · Carbon isotopes, 14 C and 13 C, in atmospheric CO 2 are changing in response to fossil fuel emissions and other human activities. Future simulations using different SSPs show continued changes in isotopic ratios that depend on fossil fuel emissions and, for 13 C, BECCS.
14 mar 2016 · We identify four major patterns of variability of the carbon cycle spanning the length of our record: (i) a millennial-scale increase in CO 2 and decrease in δ 13 C-CO 2 during the early part of Heinrich Stadial 1 (17.6–15.5 ka); (ii) rising CO 2 with generally increasing δ 13 C-CO 2 during the later portion of Heinrich Stadial 1 (15.5–14 ...
1 gru 2019 · TDLAS measures the mixing ratios of stable isotopes of carbon dioxide in the air (e.g., the isotopologues, 12 C 16 O 2, 13 C 16 O 2 and 16 O 12 C 18 O) by comparing the infrared absorption of sample and reference gases in a specific absorption line of the spectrum (Santos et al., 2012).
By examining the isotopic mixture in the atmosphere, and knowing the isotopic fingerprint of each reservoir, atmospheric scientists can determine how much carbon dioxide is coming and going from each reservoir, making isotopes an ideal tracer of sources and sinks of carbon dioxide.
So, we know that the ratio of carbon isotopes in atmospheric carbon dioxide samples is from a mixture of sources, and we also know the unique isotopic fingerprint of each of those sources. Using these two pieces of information, scientists can figure out why trends in Δ 14 C and δ 13 C occur.
17 sty 2018 · Atmospheric effects must be taken into account when interpreting terrestrial stable carbon isotopes, with important implications for past environments and climates, and understanding plant ...
Introduction. Carbon isotopes are present in the atmosphere, ocean, and terrestrial biosphere in ratios of approximately 99% 12C/C, 1% 13C/C, and 1 × 10−1214C/C. 12C and 13C are stable isotopes while 14C is a radioactive isotope called radiocarbon.
