{
  "abstract": "The wintertime Arctic boundary layer is characterized by two distinct states, radiatively clear (cloud-free) and radiatively opaque (cloudy), which is reflected in observations as a bimodal distribution. Previous studies hypothesized that these regimes are related to an underlying bistability of the system's dynamics. We apply a drift-diffusion framework based on the two leading terms of the Kramers-Moyal expansion to observations from 15 winter periods in Ny-Alesund, Norway. Our model captures the bimodality; we find a single stable point for the deterministic drift, however, which questions the existence of bistable deterministic dynamics. Instead, the observed regimes can be attributed to state-dependent stochastic fluctuations with maximum amplitude close to the clear-cloudy transition. The position of the stable point depends on the meteorological conditions. Controlling for synoptic variability does not remove the state-dependence of diffusion, however. The cloudy regime is associated with southwesterly winds, high specific humidities, and uplifting motion, the latter two being conducive for cloud formation, while the cloud-free regime occurs under drier conditions and northeasterly winds. Through an illustrative example, we suggest a possible process-based interpretation of our statistical analysis. The nonlinear onset of cloud formation, once atmospheric humidity reaches saturation, could map state-independent fluctuations in humidity to state-dependent fluctuations in cloudiness.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.02205",
  "author_total": 4,
  "authors": [
    {
      "name": "Nadja Omanovic"
    },
    {
      "name": "J. Antoon van Hooft"
    },
    {
      "name": "Valentina Zeni"
    },
    {
      "name": "Franziska Glassmeier"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9kg4wx6de9643.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.02205",
  "fulltext_url": null,
  "id": "9kg4wx6de9643",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.02205",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "physics.ao-ph"
    ],
    [
      "openalex",
      "1902|Meteorological Phenomena and Simulations"
    ]
  ],
  "openalex": "W7172449150",
  "pdf_url": "https://arxiv.org/pdf/2608.02205",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9kg4wx6de9643.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2608.02205",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.02205"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "arxiv:physics.ao-ph",
      "subfield": "atmospheric"
    }
  ],
  "title": "Arctic bimodality reflects enhanced variability in the clear-cloudy transition rather than bistability",
  "title_text": "Arctic bimodality reflects enhanced variability in the clear-cloudy transition rather than bistability",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/9kg4wx6de9643",
  "venue": "arXiv",
  "versions": []
}