New Constraints on Isotopic Effects and Major Sources of Nitrate in Atmospheric Particulates by Combining δ<sup>15</sup>N and Δ<sup>17</sup>O Signatures
Wei Song, Xueyan Liu, Cong‐Qiang Liu
Abstract
Abstract Particulate nitrate ( ) is a key component of atmospheric nitrogen (N) pollution and deposition. Stable N isotopes of can record sources of atmospheric N oxides (NO x ). However, because N isotope effects between NO x and have not been constrained, the apportionment of atmospheric NO x sources remains not quantitative. By collating observation data of dual 15 N and 17 O isotopes and environmental parameters, we calculated values and established a new relationship to constrain values based on the 17 O anomaly of . By considering values and using the Stable Isotope Analysis in the R model, we reevaluated the relative contributions between major fossil and non‐fossil fuel NO x emissions, and we found that the latter had generally higher contributions (56% ± 5%) than the former (44% ± 3%) among different sites. This study improves the isotope tracing technique of atmospheric and informs that non‐fossil fuel NO x emissions should be underscored in future emission management.