{
  "id": "1903.04363",
  "version": "v1",
  "published": "2019-03-11T15:19:13.000Z",
  "updated": "2019-03-11T15:19:13.000Z",
  "title": "Effects of small-scale dynamo and compressibility on the $Λ$ effect",
  "authors": [
    "Petri J. Käpylä"
  ],
  "comment": "7 pages, 6 figures, submitted to Astron. Nachr",
  "categories": [
    "astro-ph.SR",
    "physics.flu-dyn"
  ],
  "abstract": "The $\\Lambda$ effect describes a rotation-induced non-diffusive contribution to the Reynolds stress. It is commonly held responsible for maintaining the observed differential rotation of the Sun and other late-type stars. Here the sensitivity of the $\\Lambda$ effect to small-scale magnetic fields and compressibility is studied by means of forced turbulence simulations either with anisotropic forcing in fully periodic cubes or in density-stratified domains with isotropic forcing. Effects of small-scale magnetic fields are studied in cases where the magnetic fields are self-consistently generated by a small-scale dynamo. The results show that small-scale magnetic fields lead to a quenching of the $\\Lambda$ effect which is milder than in cases where also a large-scale field is present. The effect of compressibility on the $\\Lambda$ effect is negligible in the range of Mach numbers from $0.015$ to $0.8$. Density stratification induces a marked anisotropy in the turbulence and a vertical $\\Lambda$ effect if the forcing scale is roughly two times larger than the density scale height.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-03-11T15:19:13.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "small-scale dynamo",
      "small-scale magnetic fields",
      "compressibility",
      "density stratification induces",
      "density scale height"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}