{
  "abstract": "Aerosols play a critical role in Earth's climate, yet changes in their physicochemical properties during atmospheric transport remain an important source of uncertainty in predicting their climate impacts. Observational constraints on these changes over the first few hours of urban plume transport remain limited. Here, we investigated urban-to-downwind variations in aerosol physicochemical and optical properties using coordinated ground-based and airborne measurements in Paris and its downwind region, covering estimated plume transport times of ∼ 2–6 h. Urban plumes contributed modestly to downwind particle number concentrations in the 80–200 nm range and moderately enhanced submicron particulate matter (PM ₁ ) relative to the surrounding background. Organic aerosol (Org) dominated PM ₁ mass at both the urban site and downwind. Non-refractory PM ₁ component mass fractions and secondary aerosol mass relative to CO showed limited urban-to-downwind variations, whereas the relative contribution of more oxidized Org increased downwind. In contrast, optical properties exhibited pronounced differences, with higher plume-average single-scattering albedo at both 450 and 630 nm downwind. The complex refractive index shifted from lower real (∼ 1.35–1.40) and higher imaginary (∼ 0.03–0.08) components near the urban source to higher real (∼ 1.45–1.50) and lower imaginary (∼ 0.015–0.02) components downwind. The average absorption Ångström exponent was also higher downwind, indicating stronger wavelength dependence of aerosol absorption. These observations reveal systematic urban-to-downwind differences in aerosol physicochemical and optical properties consistent with atmospheric processing during transport. They highlight the importance of accounting for spatially evolving aerosol properties in atmospheric models and remote-sensing retrievals.",
  "abstract_shown": true,
  "affiliations": [
    "Université Paris Cité (Paris, France)",
    "Université Paris-Est Créteil (Créteil, France)",
    "Centre National de la Recherche Scientifique (Paris, France)"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 28,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Chenjie Yu",
      "orcid": "0000-0001-9831-4558"
    },
    {
      "name": "Ludovico Di Antonio",
      "orcid": "0000-0003-0528-7082"
    },
    {
      "name": "Peter F. DeCarlo",
      "orcid": "0000-0001-6385-7149"
    },
    {
      "name": "Benjamin A. Nault",
      "orcid": "0000-0001-9464-4787"
    },
    {
      "name": "Alejandra Velazquez-Garcia",
      "orcid": "0000-0002-0259-539X"
    },
    {
      "name": "Eleonora Aruffo",
      "orcid": "0000-0002-9164-7293"
    },
    {
      "name": "Piero Di Carlo",
      "orcid": "0000-0003-4971-4509"
    },
    {
      "name": "Cyrielle Denjean"
    },
    {
      "name": "Sarah Tinorua",
      "orcid": "0009-0005-5411-6855"
    },
    {
      "name": "Thierry Bourrianne"
    },
    {
      "name": "Diana L. Pereira"
    },
    {
      "name": "Kevin Tu"
    },
    {
      "name": "Edouard Pangui"
    },
    {
      "name": "Mathieu Cazaunau"
    },
    {
      "name": "Astrid Bauville"
    },
    {
      "name": "Noël Grand"
    },
    {
      "name": "Antonin Bergé"
    },
    {
      "name": "Claudia Di Biagio",
      "orcid": "0000-0001-8273-6211"
    },
    {
      "name": "Aline Gratien"
    },
    {
      "name": "Matthias Beekmann"
    },
    {
      "name": "Guillaume Siour",
      "orcid": "0000-0002-5940-4902"
    },
    {
      "name": "Gilles Foret"
    },
    {
      "name": "Barbara D'Anna",
      "orcid": "0000-0001-8915-4097"
    },
    {
      "name": "Julien Kammer",
      "orcid": "0000-0003-0839-9872"
    },
    {
      "name": "Huihui Wu",
      "orcid": "0000-0001-6469-2892"
    },
    {
      "name": "Christopher Cantrell",
      "orcid": "0000-0002-3844-1560"
    },
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Paola Formenti",
      "orcid": "0000-0002-0372-1351"
    },
    {
      "name": "Vincent Michoud"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dn1v0djzqm9kq.bib",
  "cited_by": 0,
  "doi": "10.5194/acp-26-15055-2026",
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    "1680-7324"
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  "language": null,
  "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": [
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      "feed-journal",
      "earth/atmospheric"
    ],
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      "openalex",
      "1902|Atmospheric chemistry and aerosols"
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  "pdf_url": "https://acp.copernicus.org/articles/26/15055/2026/acp-26-15055-2026.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": "Copernicus GmbH",
  "ris": "https://research.draconitic.com/paper/dn1v0djzqm9kq.ris",
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  "title": "Urban-to-downwind variations in aerosol composition and optical properties in the Paris urban plume from coordinated airborne and ground-based observations",
  "title_text": "Urban-to-downwind variations in aerosol composition and optical properties in the Paris urban plume from coordinated airborne and ground-based observations",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:34Z",
  "url": "https://research.draconitic.com/paper/dn1v0djzqm9kq",
  "venue": "Atmospheric Chemistry and Physics",
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