English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. The isotopic composition of nitrogen and oxygen in nitrogendioxide (NO2) potentially carries a wealth of information about thedynamics of the nitrogen oxides (NOx = nitric oxide (NO) + NO2) chemistry in the atmosphere. While nitrogen isotopes of NO2are subtle indicators of NOx emissions and chemistry, oxygen isotopesare believed to reflect only the O3 / NOx / VOC chemical regime in different atmospheric environments. In order to access this potential tracerof the tropospheric chemistry, we have developed an efficient active methodto trap atmospheric NO2 on denuder tubes and measured, for the firsttime, its multi-isotopic composition (δ15N, δ18O,and Δ17O). The Δ17O values of NO2 trapped atour site in Grenoble, France, show a large diurnal cycle peaking in latemorning at (39.2 ± 0.3) ‰ and decreasing at nightuntil (20.5 ± 0.3) ‰. On top of this diurnalcycle, Δ17O also exhibits substantial daytime variability (from29.7 ‰ to 39.2 ‰), certainly driven by changes in theO3 to peroxyl radicals (RO2) ratio. The nighttime decay ofΔ17O(NO2) appears to be driven by NO2 slow removal,mostly from conversion into N2O5, and its formation from thereaction between O3 and freshly emitted NO. As expected from anighttime Δ17O(NO2) expression, our Δ17O(NO2) measured towards the end of the night is quantitativelyconsistent with typical values of Δ17O(O3). Daytime Nisotope fractionation is estimated using a general expression linking it toΔ17O(NO2). An expression is also derived for the nighttimeN isotope fractionation. In contrast to Δ17O(NO2),δ15N(NO2) measurements exhibit little diurnal variability(−11.8 ‰ to −4.9 ‰) with negligible isotope fractionations between NO and NO2, mainly due to highNO2 / NOx ratios, excepted during the morning rush hours. The mainNOx emission sources are estimated using a Bayesian isotope mixingmodel, indicating the predominance of traffic emissions in this area. Thesepreliminary results are very promising for using the combination ofΔ17O and δ15N of NO2 as a probe of theNOx sources and fate and for interpreting nitrate isotopic compositionrecords.

atmospheric chemistry and physics

Measurement report: Nitrogen isotopes (&amp;lt;i&amp;gt;δ&amp;lt;/i&amp;gt;&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;N) and first quantification of oxygen isotope anomalies (&amp;lt;i&amp;gt;Δ&amp;lt;/i&amp;gt;&amp;lt;sup&amp;gt;17&amp;lt;/sup&amp;gt;O, &amp;lt;i&amp;gt;δ&amp;lt;/i&amp;gt;&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;O) in atmospheric nitrogen dioxide