Related papers: Distribution of Electric Currents in Solar Active …
A flare and fast coronal mass ejection originated between solar active regions NOAA 11514 and 11515 on July 1, 2012 in response to flux emergence in front of the leading sunspot of the trailing region 11515. Analyzing the evolution of the…
Magnetic active regions on the Sun are harbingers of space weather events. Understanding the physics of how they form and evolve will improve space weather forecasting. Our aim is to characterise the surface magnetic field and flows for a…
During solar minimum, the Sun is relatively inactive with few sunspots observed on the solar surface. Consequently, we observe a smaller number of highly energetic events such as solar flares or coronal mass ejections (CMEs), which are…
Magnetic flux ropes (FRs) are twisted structures appearing on the sun, predominantly in the magnetically concentrated regions. These structures appear as coronal features known as filaments or prominences in H$\alpha$ observations, and as…
Measurements of the interplanetary magnetic field (IMF) over several solar cycles do not agree with computed values of open magnetic flux from potential field extrapolations. The discrepancy becomes greater around solar maximum in each…
Like the solar corona, the external magnetic field of magnetars is twisted by surface motions of the star. The twist energy is dissipated over time. We discuss the theory of this activity and its observational status. (1) Theory predicts…
Magnetic fields and flows in coronal structures, for example, in gradual phases in flares, can be described by 2D and 3D magnetohydrostatic (MHS) and steady magnetohydrodynamic (MHD) equilibria. Within a physically simplified, but exact…
It is shown that the connection of sufficiently fast flows with dynamical channels for particle escape in the Solar Corona is rather direct: it depends on their ability to deform (in specific cases to distort) the ambient magnetic field…
Parker has hypothesised that, in a perfectly ideal environment, complex photospheric motions acting on a continuous magnetic field will result in the formation of tangential discontinuities corresponding to singular currents. We review…
Strong solar flares and coronal mass ejections (CMEs) are prone to originate within and near active regions (ARs) with a high magnetic complexity. Therefore, to better understand the generation mechanism of flares and the resultant CME…
Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…
Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since…
Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic…
Observations of flare-heated electrons in the corona typically suggest confinement of electrons. The confinement mechanism, however, remains unclear. The transport of coronal hot electrons into ambient plasma was recently investigated by…
Starting from a realistically sheared magnetic arcade connecting chromospheric, transition region to coronal plasma, we simulate the in-situ formation and sustained growth of a quiescent prominence in the solar corona. Contrary to previous…
Magnetic flux ropes are characterized by coherently twisted magnetic field lines, which are ubiquitous in magnetized plasmas. As the core structure of various eruptive phenomena in the solar atmosphere, flux ropes hold the key to…
The structure and dynamics of the solar corona is dominated by the magnetic field. In most areas in the corona magnetic forces are so dominant that all non-magnetic forces like plasma pressure gradient and gravity can be neglected in the…
Magnetic fields in the sun's outer atmosphere -- the corona -- control both solar-wind acceleration and the dynamics of solar eruptions. We present the first clear observational evidence of coronal magnetic nulls in off-limb linearly…
We present simulations modeling closed regions of the solar corona threaded by a strong magnetic field where localized photospheric vortical motions twist the coronal field lines. The linear and nonlinear dynamics are investigated in the…
Magnetic flux emergence and decay in the Sun span from days to months. However, their tracking is typically limited to about half a solar rotation when relying on single-vantage-point observations. Combining observations from both the…