{
  "id": "2212.01308",
  "version": "v1",
  "published": "2022-12-02T16:59:26.000Z",
  "updated": "2022-12-02T16:59:26.000Z",
  "title": "Characteristic Scales of Complexity and Coherence within Interplanetary Coronal Mass Ejections: Insights from Spacecraft Swarms in Global Heliospheric Simulations",
  "authors": [
    "Camilla Scolini",
    "Reka M. Winslow",
    "Noé Lugaz",
    "Stefaan Poedts"
  ],
  "categories": [
    "astro-ph.SR",
    "physics.space-ph"
  ],
  "abstract": "Many aspects of the three-dimensional (3-D) structure and evolution of interplanetary coronal mass ejections (ICMEs) remain unexplained. Here, we investigate two main topics: (1) the coherence scale of magnetic fields inside ICMEs, and (2) the dynamic nature of ICME magnetic complexity. We simulate ICMEs interacting with different solar winds using the linear force-free spheromak model incorporated into the EUHFORIA model. We place a swarm of ~20000 spacecraft in the 3-D simulation domain and characterize ICME magnetic complexity and coherence at each spacecraft based on simulated time series. Our simulations suggest that ICMEs retain a lower complexity and higher coherence along their magnetic axis, but that a characterization of their global complexity requires crossings along both the axial and perpendicular directions. For an ICME of initial half angular width of $45^\\circ$ that does not interact with other large-scale solar wind structures, global complexity can be characterized by as little as 7-12 spacecraft separated by $25^\\circ$, but the minimum number of spacecraft rises to 50-65 (separated by $10^\\circ$) if interactions occur. Without interactions, ICME coherence extends for $45^\\circ$, $20^\\circ$-$30^\\circ$, $15^\\circ$-$30^\\circ$, and $0^\\circ$-$10^\\circ$ for $B$, $B_\\phi$, $B_\\theta$, and $B_r$, respectively. Coherence is also lower in the ICME west flank compared to the east flank due to Parker spiral effects. Moreover, coherence is reduced by a factor of 3-6 by interactions with solar wind structures. Our findings help constrain some of the critical scales that control the evolution of ICMEs and aid in the planning of future dedicated multi-spacecraft missions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-12-02T16:59:26.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "interplanetary coronal mass ejections",
      "global heliospheric simulations",
      "characteristic scales",
      "spacecraft swarms",
      "icme magnetic complexity"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}