English

Small-scale impulsive EUV emission enhancements along network loops

Solar and Stellar Astrophysics 2026-03-31 v1

Abstract

Network loops are a common feature in the quiet Sun. The physical processes sustaining their energy budget is still under discussion. We rely on a multi-instrumental (Solar Orbiter/EUI, Solar Orbiter/PHI, IRIS) observation of a six hours quiet Sun region to measure the dynamics and the possible magnetic drivers of impulsive EUV emission enhancements along network loops. We report the detection of small-scale impulsive EUV emission enhancements with EUI/HRIEUV in three network loops. We selected four EUV emission enhancements to measure their plane-of-sky velocities in HRIEUV; their Doppler velocities in the line (log Si iv T = 4.8) with IRIS ; their possible relation to small-scale flux emergence and fluctuation in one of the loop footpoint. The plane-of-sky velocities of the four EUV emission enhancements have a component that seem to appear almost instantaneously along the loop (more than 220 km/s) ; and two of them had a co-temporal component with a PoS velocity of up to , starting near one of the loop footpoint. In one case, we measured with IRIS a co-temporal intensity increase in the line associated with Doppler velocities down to and up to along the line of sight. Finally, we found evidence of small-scale (8E16 Mx) mixed polarity field emergence and fluctuation near one of the loop footpoint. We concluded that the fast component on the plane-of-sky are consistent with a thermal transfer or supersonic plasma flows, while the slower component is consistent with plasma flows. A possible physical origin for these EUV emission enhancements would be magnetic reconnection driven by either photospheric motion of the loop footpoints or by the reconnection of the loop with small-scale magnetic bipoles.

Keywords

Cite

@article{arxiv.2603.28601,
  title  = {Small-scale impulsive EUV emission enhancements along network loops},
  author = {A. Dolliou and H. Peter and S. Mandal and L. P. Chitta and L. Teriaca and Y. Chen and D. Calchetti},
  journal= {arXiv preprint arXiv:2603.28601},
  year   = {2026}
}

Comments

17 pages, 18 figures, 1 table, accepted in A&A

R2 v1 2026-07-01T11:44:21.586Z