Fig. 5: The 14CO galactic source function.
From: Radiocarbon monoxide indicates increasing atmospheric oxidizing capacity
a, b Zonal-mean (ZM) rate of production of 14CO (molecules cm−3 year−1 STP) at SMPs of 400 and 800 MeV. Thick contour: For illustration, the approximate annual-average tropopause pressure. c 14CO production rate averaged over the Antarctic polar cap (90°S-60°S) as a function of the SMP (section “Normalization of the 14CO data”) and pressure. Contours: Polynomial regression fit to the logarithm of the 14C production rate (equation 2).
