{
  "abstract": "A large number of photometric and photographic position data of noctilucent clouds (NLC) obtained at 54-61 deg N, 29-50 deg E in 2020-2026 is used, comprising about 20,000 individual measurements of the altitude of NLC fragments recorded by a number of cameras. Comparison with published long-base triangulation measurements starting from 1890 reveals a descending trend in NLC altitude with a 99.5% confidence level. The current descent rate is -1.2 km per century, or half of the model prediction based on the current increase of CO2 in the atmosphere. Other factors that can influence NLC altitude are considered: solar longitude (season), local solar time, lunar tides, latitude, and solar activity. Two independent methods of NLC altitude determination based on the same photometric data are considered and compared.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41750",
  "author_total": 6,
  "authors": [
    {
      "name": "Oleg S. Ugolnikov"
    },
    {
      "name": "Ilya S. Yankovsky"
    },
    {
      "name": "Maxim V. Klimenko"
    },
    {
      "name": "Egor O. Ugolnikov"
    },
    {
      "name": "Andrey M. Tatarnikov"
    },
    {
      "name": "Sergey G. Zheltoukhov"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5tbka2zrdgmf7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41750",
  "fulltext_url": null,
  "id": "5tbka2zrdgmf7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41750",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.ao-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.41750",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5tbka2zrdgmf7.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41750",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41750"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "arxiv:physics.ao-ph",
      "subfield": "atmospheric"
    }
  ],
  "title": "Long-Term Trend of Noctilucent Cloud Altitude Detected: A Comparison of Positional Data with Historical Measurements",
  "title_text": "Long-Term Trend of Noctilucent Cloud Altitude Detected: A Comparison of Positional Data with Historical Measurements",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/5tbka2zrdgmf7",
  "venue": "arXiv",
  "versions": []
}