This function calculates mole fractions of 12CO2 based on the total CO2 mole fraction, the delta13C value of the mixture, and the assumed fraction of CO2 that does not correspond to 12CO2 or 13CO2 (assumed fixed at 0.00474, e.g., Griffis et al. 2004 Agricultural and Forest Meteorology)
Author
Rich Fiorella rfiorella@lanl.gov