Fig. 2: Normalized 14CO measurements and their trends.
From: Radiocarbon monoxide indicates increasing atmospheric oxidizing capacity
a, c Normalized measurements 14COnorm as functions of the times of the measurements (section “Normalization for seasonal and solar influences”). The thick black lines mark least-squares piecewise linear regression fits for central nodes in 1997. Colours mark the solar modulation parameter (SMP) at the times of the measurements. Vertical lines denote the standard measurement errors. The numbers are the post-1997 trends and their uncertainties. b, d Post-1997 trends in 14COnorm (% a−1) and their standard errors as functions of the month of the year, using the same piecewise-linear fitting method as used in panels (a) and (c) applied to subsets of the data grouped by month.
