Parallel-cascade-based mechanisms for heating solar coronal loops: test against observations

Authors Organisations
  • Bo Li(Author)
    Shandong University at Weihai
  • Haixia Xie(Author)
    Shandong University at Weihai
  • Xing Li(Author)
  • Li-Dong Xia(Author)
    Shandong University at Weihai
Type Article
Original languageEnglish
Pages (from-to)155-155
Number of pages1
JournalAstronomical Society of the Pacific Conference Series
Volume488
Publication statusPublished - 01 Jun 2014
Event8th International Conference of Numerical Modeling of Space Pasma Flows (ASTRONUM 2013) - Biarritz, France
Duration: 01 Jul 201305 Jul 2013
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Abstract

The heating of solar coronal loops is at the center of the problem of coronal heating. Given that the origin of the fast solar wind has been tracked down to atmospheric layers with transition region or even chromospheric temperatures, it is worthy attempting to address whether the mechanisms proposed to provide the basal heating of the solar wind apply to coronal loops as well. We extend the loop studies based on a classical parallel-cascade scenario originally proposed in the solar wind context by considering the effects of loop expansion, and perform a parametric study to directly contrast the computed loop densities and electron temperatures with those measured by TRACE and YOHKOH/SXT. This comparison yields that with the wave amplitudes observationally constrained by SUMER measurements, while the computed loops may account for a significant fraction of SXT loops, they seem too hot when compared with TRACE loops. Lowering the wave amplitudes does not solve this discrepancy, introducing magnetic twist will make the comparison even less desirable. We conclude that the nanoflare heating scenario better explains ultraviolet loops, while turbulence-based steady heating mechanisms may be at work in heating a fraction of soft X-ray loops.

Keywords

  • Astrophysics - Solar and Stellar Astrophysics