{
  "abstract": "Three-minute ($\\sim$5 mHz) oscillations are a prominent signature of wave propagation in the solar chromosphere, but their measured power can vary substantially between full-disc observations and small, high-resolution fields of view. We investigate whether chromospheric magnetic canopy topology, particularly its lateral continuity and areal filling, modulates field-of-view-averaged three-minute power. We analyse H$α$ and Ca II 8542 Å spectral imaging from the Swedish 1-m Solar Telescope, comparing canopy-poor quiet-Sun scenes with canopy-dominated active-region environments, complemented by radiative-MHD Bifrost simulations of canopy-poor and canopy-rich atmospheres. We compute field-of-view-averaged power spectra from fixed-wavelength intensities and bisector-derived velocities in the observations, and from synthetic intensities, velocities, and temperature proxies in the simulations. We also quantify the relation between integrated 3-5 mHz excess power and canopy filling factor, using HMI-based magnetic-field extrapolations for the observations. In both observations and simulations, canopy-poor scenes show clear 3-5 mHz power enhancements, whereas canopy-dominated scenes show strongly reduced measured power. The trend is present in H$α$ and Ca II 8542 Å intensities and is supported by complementary velocity and temperature proxies. Integrated 3-5 mHz excess power decreases with increasing canopy filling factor. We conclude that chromospheric field-of-view-averaged three-minute power is a topology-weighted observable: dense, laterally continuous magnetic canopies can strongly reduce the measured large-scale three-minute signature without requiring the absence of local wave activity. This provides a practical criterion for interpreting chromospheric oscillation power as a proxy for atmospheric wave energy in the Sun and in magnetised cool-star atmospheres.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.30707",
  "author_total": 14,
  "authors": [
    {
      "name": "Shahin Jafarzadeh"
    },
    {
      "name": "David B. Jess"
    },
    {
      "name": "Marco Stangalini"
    },
    {
      "name": "Bernhard Fleck"
    },
    {
      "name": "Richard J. Morton"
    },
    {
      "name": "Samuel D. T. Grant"
    },
    {
      "name": "Peter H. Keys"
    },
    {
      "name": "Luc Rouppe van der Voort"
    },
    {
      "name": "Sven Wedemeyer"
    },
    {
      "name": "Tiago M. D. Pereira"
    },
    {
      "name": "Mikołaj Szydlarski"
    },
    {
      "name": "Elias R. Udnæs"
    },
    {
      "name": "Thomas Wiegelmann"
    },
    {
      "name": "Markus Roth"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/e0tx8p6hz435s.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.30707",
  "fulltext_url": null,
  "id": "e0tx8p6hz435s",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.30707",
  "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",
      "astro-ph.SR"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2608.30707",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/e0tx8p6hz435s.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2608.30707",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.30707"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "The umbrella effect: Magnetic canopy topology modulates spatially averaged chromospheric three-minute power",
  "title_text": "The umbrella effect: Magnetic canopy topology modulates spatially averaged chromospheric three-minute power",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/e0tx8p6hz435s",
  "venue": "arXiv",
  "versions": []
}