{
  "abstract": "Nitrous oxide (N₂O) is a potent greenhouse gas involved in the destruction of stratospheric ozone. Past atmospheric mixing ratios of N₂O are archived in ice cores; however, the presence of in situ N₂O production in dust-rich Antarctic ice complicates their accurate reconstruction, especially during glacial periods. This production occurs in extremely cold ice and without sunlight. This study aims to understand the reaction producing N₂O in Antarctic ice by identifying the precursors and the reaction pathway. We compared the oxygen and nitrogen bulk and position-specific isotope composition of in situ N₂O in ice cores to the isotopic composition of nitrate (NO3-), a possible precursor of N₂O. The 15 N signature of NO3- is fully transferred into the central N atom (N α ) of in situ N₂O, but it is not transferred into the terminal N atom (N β ), resulting in a 50 % transfer of the 15 N signature of NO3- into the bulk 15 N isotopic composition. These findings suggest that the in situ N₂O production involves two different nitrogen precursors present in ice: the central N atom (Nα) originates from NO3- and the terminal N atom (N β ) from a different precursor not yet identified. Oxygen isotope analysis shows that NO3- cannot be the only reservoir for the O atom of in situ N₂O. Temperature, pH, and absence of sunlight in Antarctic ice point to an abiotic N-nitrosation reaction. The limiting factor of the reaction is probably associated with mineral dust and might be Fe 2+ , reducing NO3- to NO₂- or the precursor of the Nβ atom. The site preference (SP) values of in situ N₂O are highly variable between different ice cores and depend on the bulk ¹⁵N isotopic composition of N₂O, itself depending on the ¹⁵N isotopic composition of the NO3- precursor. This finding is unexpected because SP is usually determined by the production pathway through symmetric reaction intermediates that mix the N atoms in α and β positions and average out their isotopic difference. In contrast, our results provide the first evidence of a hybrid N₂O production pathway involving an asymmetric intermediate that preserves the distinct ¹⁵N signatures of two different precursors – one contributing to the Nα atom and the other to the Nβ atom.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "name": "Lison Soussaintjean"
    },
    {
      "name": "Jochen Schmitt"
    },
    {
      "name": "Joël Savarino"
    },
    {
      "name": "J. Andy Menking"
    },
    {
      "name": "Edward J Brook"
    },
    {
      "name": "Barbara Seth"
    },
    {
      "name": "Vladimir Lipenkov"
    },
    {
      "name": "Thomas Röckmann"
    },
    {
      "name": "Hubertus Fischer"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9yzk1ggvkpdbk.bib",
  "cited_by": 0,
  "doi": "10.5194/bg-23-3939-2026",
  "fulltext_url": null,
  "id": "9yzk1ggvkpdbk",
  "issns": [
    "1726-4170",
    "1726-4189"
  ],
  "landing_url": "https://hal.science/hal-05789095v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.phys.phys"
    ],
    [
      "hal",
      "1.sdu.envi"
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      "hal",
      "2.phys.phys.phys-ao-ph"
    ],
    [
      "openalex",
      "1902|Geology and Paleoclimatology Research"
    ]
  ],
  "openalex": "W4412173259",
  "pdf_url": "https://hal.science/hal-05789095/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-06-15",
  "publisher": "European Geosciences Union",
  "ris": "https://research.draconitic.com/paper/9yzk1ggvkpdbk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:52Z",
      "native_id": "hal-05789095",
      "source": "hal",
      "url": "https://hal.science/hal-05789095v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "hal:2.phys.phys.phys-ao-ph",
      "subfield": "atmospheric"
    },
    {
      "field": "earth",
      "origin": "hal:1.sdu.envi",
      "subfield": "environmental-science"
    },
    {
      "field": "physics",
      "origin": "hal:0.phys",
      "subfield": "general"
    }
  ],
  "title": "In situ production of hybrid N₂O in dust-rich Antarctic ice",
  "title_text": "In situ production of hybrid N₂O in dust-rich Antarctic ice",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:52Z",
  "url": "https://research.draconitic.com/paper/9yzk1ggvkpdbk",
  "venue": "Biogeosciences",
  "versions": []
}