Fig. 5: Tropospheric background N₂O mixing ratio and isotopic composition (δ¹⁵N and δ¹⁵N^SP) measured in different datasets.

Scale offsets between different datasets have been corrected using overlapping periods to match the Empa dataset as described in the text. Mean data at 25-year intervals (1740–1940) and 2-year intervals (1940–2018) are shown as orange points with black outline; the standard deviation of the data averaged for each point is shown as the orange shaded region.