Modeling the Complete Nitrogen and Oxygen Isotopic Imprint of Nitrate Photolysis in Snow

Snow nitrate is vulnerable to photolytic loss that causes isotopic alteration, and thus its isotopes can potentially track the extent of snow photolysis impacts in environments where significant. Large increases δ15N-NO3− below surface have been attributed this behavior generally consistent amongst theoretical as well lab field studies. Oxygen isotope ratios are thought be influenced by secondary condensed-phase chemistry, but competing effects yet reconciled. Here we use a model simulates burial, fractionation, re-oxidation quantitatively assess these processes with aim developing framework for interpreting complete composition (δ15N, δ18O, Δ17O). This study reveals aqueous-phase chemistry important sources uncertainties modeling δ18O-NO3−.