Agricultural practices have led to a greater use of nitrogen-containing fertilizers and an increase in N₂O, an important greenhouse gas and ozone-depleting substance. Isotopic measurements can be used to differentiate sources of N₂O in the atmosphere, and the data presented here explore the isotopic composition of N₂O formed in a low-temperature plasma, similar to some forms of lightning in the atmosphere. A corona discharge was used to generate N₂O under flowing and static conditions, at pressures from approximately 0.1 to 10 Torr, a discharge voltage of 5 kV, and a discharge current of 1500 mA. Additional experiments were conducted by varying the discharge current between 75 to 1500 μA at ~0.5 Torr. Samples were analyzed using an isotope ratio mass spectrometer, and we find that the isotopic composition of N₂O produced differs in unique ways from that of other sources to the atmosphere. These differences suggest that isotopic measurements of atmospheric N₂O samples can be used to determine/investigate whether observations of local and regional enhancements in N₂O are due to lightning, as well as to constrain the source of N₂O in the upper stratosphere, mesosphere and thermosphere.

​​​​​​The experimental methods and data processing are described in detail in Smith et al. (2021).

• • Experiments in Table 2 are the averages of similar groups of experiments that are shown in Table S2. Specifically, Table 2-Averaged experimental results are the following from Table S2-unaveraged experimental results.
    • 1500 μA at 0.500, 0.550, and 0.520 Torr (rows 2-4)
    • 300 μA at 0.550 and 0.540 Torr (rows 7-8)
    • 150 μA at 0.560, 0.57, and 0.56 Torr (rows 9-11)
    • 1500 μA at 9.76 and 9.73 Torr (rows 18-19)
    • 1500 μA at 9.85 and 9.69 Torr static runs (rows 20-21)
  • For additional usage notes please see comments in the excel file.