Table 2.
Summary of previously reported δ15N-NOx values sorted by emission source type.
| Source type | δ15N-NOx | Mean (‰) | Standard deviation (‰) | References |
|---|---|---|---|---|
| Mobile source | − 8.1‰ to + 9.8‰ | − 2.5 | 2.7 | Walters, Goodwin, et al.66a, Miller et al.65 |
| Biomass burning | − 7‰ to + 12‰ | 1.0 | 4.1 | Fibiger & Hastings45 |
| Stationary source | − 19.7‰ to − 13.9‰ | − 16.5 | 1.7 | Walters, Tharp, et al. (2015) |
| Biogenic soil emission | − 59.8‰ to − 14.2‰ | − 33.2 | 9.6 | Li & Wang51, Yu & Elliot59, Miller et al. (2018) |
aOnly a portion of the measurements from this paper were used since they were measured with a cold, neutral engine, which wouldn’t be relevant for ambient temperatures.