ИСТИНА

A revision of the basic mechanisms of magnetospheric dynamics (see, for example, GRL, 2025, doi:10.1029/2024GL114315) includes clarification of the level of turbulence of magnetospheric domains, the spatial localization of the auroral oval and auroral structures. Among the current tasks is also solving the problem of the formation of narrow auroral structures, the dimensions of which along the magnetic field lines far exceed their transverse dimensions. Such structures form rayed arcs, often called picket arcs. At the zenith, this form of auroral display is called a corona. Rayed arcs are often observed at latitudes of the auroral oval, but can also be observed in the cusp region (GA, 2024, doi:10.1134/S0016793224600103). Rayed arcs are the brightest auroral structures, with brightness far exceeding that of other auroral forms. During observations, small-scale fluctuations of the electric and magnetic fields are simultaneously recorded, which led to the dominance of ideas about the acceleration of electrons, causing the appearance of rayed arcs by Alfven waves and the flow of energy into the arc along magnetic field lines. The advantages of an alternative mechanism, discussed in (Proc. XLVIII Annual Seminar, Apatity, doi:10.51981/2588-0039.2025.48.002) for creating a rayed arc are highlighted.