{
  "abstract": "Titan’s upper atmospheric layers provide a unique opportunity to study how photochemistry, photoionization, haze microphysics, and escape processes shape its atmospheric chemical structure, providing a unique benchmark for understanding these processes in exoplanets. Using a 1D first-principles approach, we extend the Kompot model to simulate Titan’s upper atmosphere and investigate its thermal and chemical structure, and Jeans escape. We performed self-consistent simulations of Titan’s upper atmosphere, above the dense haze layer, over a 1D radial grid by solving the coupled hydrodynamics, thermal and photochemical kinetic, and energy balance equations. We considered heating by stellar X-ray and ultraviolet (XUV) and infrared radiation, and cooling due to radiative emission of methane ($\\text{CH}_{4}$) and hydrogen cyanide ($\\text{HCN}$). We also included additional 19 photochemical and 117 thermal reactions to Kompot’s standard chemical network. Our modelled atmospheric temperature structures lie within the observed variability of Titan’s atmospheric temperature profile. Our simulations reproduce observed nitrogen ($\\text{N}_{2}$) and $\\text{CH}_{4}$ densities in the upper atmosphere, and abundance of minor chemical species also broadly agree with observationally derived abundances. Near the exobase, our $\\text{CH}_{4}$ mixing ratio overlaps with Cassini–Huygens results, and our model $\\text{H}_{2}$ mixing ratios also exhibit broad agreement with observations. Our simulations suggest no significant thermal loss of $\\text{CH}_{4}$, even under the conditions of an early Sun’s XUV environment.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Astrophysics, University of Vienna , Türkenschanzstrasse 17, A-1180 Vienna ,",
    "Department of Physics and Astronomy, University College London , London WC1E 6BT ,",
    "International Institute for Applied Systems Analysis , Schloßplatz 1, A-2361 Laxenburg ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Sudeshna Boro Saikia",
      "orcid": "0000-0002-3673-3746"
    },
    {
      "affs": [
        1
      ],
      "name": "Jonathan Tennyson",
      "orcid": "0000-0002-4994-5238"
    },
    {
      "affs": [
        1
      ],
      "name": "Shuchen Ji"
    },
    {
      "affs": [
        0
      ],
      "name": "Nils-Martin Robeling"
    },
    {
      "affs": [
        0
      ],
      "name": "Ivan Stanković"
    },
    {
      "affs": [
        0
      ],
      "name": "Gwenaëlle Van Looveren",
      "orcid": "0000-0003-3782-4292"
    },
    {
      "affs": [
        0
      ],
      "name": "Simon Schleich"
    },
    {
      "affs": [
        2
      ],
      "name": "Colin P Johnstone"
    },
    {
      "affs": [
        0
      ],
      "name": "Kristina G Kislyakova"
    },
    {
      "affs": [
        0
      ],
      "name": "Manuel Güdel"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/202sxfpgsz70m.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag1951",
  "fulltext_url": null,
  "id": "202sxfpgsz70m",
  "issns": [
    "0035-8711",
    "1365-2966"
  ],
  "landing_url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1951/8916626",
  "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": [
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7221796604",
  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1951/71948412/stag1951.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/202sxfpgsz70m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:17Z",
      "native_id": "10.1093/mnras/stag1951",
      "source": "crossref",
      "url": "https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1951/8916626"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Astro and Planetary Science",
      "subfield": "planetary"
    }
  ],
  "title": "The physical and chemical structure of Titan’s upper atmosphere: energy balance, photochemistry, and Jeans escape",
  "title_text": "The physical and chemical structure of Titan’s upper atmosphere: energy balance, photochemistry, and Jeans escape",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/202sxfpgsz70m",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": []
}