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Coronal mass ejections (CMEs) and eruptive flares (EFs) are the most energetic explosions in the solar system. Their underlying origin is the free energy that builds up slowly in the sheared magnetic field of a filament channel. We report…
The underlying origin of solar eruptive events (SEEs), ranging from giant coronal mass ejections to small coronal-hole jets, is that the lowest-lying magnetic flux in the Sun's corona undergoes the continual buildup of stress and free…
Small-scale explosive events or microflares occur throughout the chromospheric network of the Sun. They are seen as sudden bursts of highly Doppler shifted spectral lines of ions formed at temperatures in the range 2x10^4 - 5x10^5 K. They…
One of the greatest challenges in solar physics is understanding the heating of the Sun's corona. Most theories for coronal heating postulate that free energy in the form of magnetic twist/stress is injected by the photosphere into the…
Minifilaments are widespread small-scale structures in the solar atmosphere. To better understand their formation and eruption mechanisms, we investigate the entire life of a sigmoidal minifilament located below a large quiescent filament…
A possible key element for large-scale energy release in the solar corona is an MHD kink instability in a single twisted magnetic flux tube. An initial helical current sheet fragments in a turbulent way into smaller-scale sheets, similarly…
We combine a convectively driven dynamo in a spherical shell with a nearly isothermal density-stratified cooling layer that mimics some aspects of a stellar corona to study the emergence and ejections of magnetic field structures. This…
The magnetic breakout model, in which reconnection in the corona leads to destabilization of a filament channel, explains numerous features of eruptive solar events, from small-scale jets to global-scale coronal mass ejections (CMEs). The…
Current analytical and numerical modelling suggest the existence of ubiquitous thin current sheets in the corona that could explain the observed heating requirements. On the other hand, new high resolution observations of the corona…
Evidence for the emergence of twisted flux tubes into the solar atmosphere has, so far, come from indirect signatures. In this work, we investigate the topological input of twisted flux tube emergence directly by studying helicity and…
Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-turbulence spectrum and ultimately heating/accelerating the…
The solar surface is covered by high-speed jets transporting mass and energy into the solar corona and feeding the solar wind. The most prominent of these jets have been known as spicules. However, the mechanism initiating these eruptions…
Solar X-ray jets are evidently made by a burst of reconnection of closed magnetic field in a jet's base with ambient "open" field (1,2). In the widely-accepted version of the "emerging-flux" model, that reconnection occurs at a current…
Flaring release of magnetic energy in solar corona is only possible if the magnetic field deviates from a potential one. We show that the linear MHD modes excited on top of the non-potential magnetic field possess a nonzero kinetic…
Helicity is a fundamental property of magnetic fields, conserved in ideal MHD. In flux rope topology, it consists of twist and writhe helicity. Despite the common occurrence of helical structures in the solar atmosphere, little is known…
Recent observations have revealed that many solar coronal jets involve the eruption of miniature versions of large-scale filaments. Such "mini-filaments" are observed to form along the polarity inversion lines of strong, magnetically…
Recent investigations indicate that solar coronal jets result from eruptions of small-scale chromospheric filaments, called minifilaments; that is, the jets are produced by scaled-down versions of typical-sized filament eruptions. We…
Two of the most important features of the solar atmosphere are its hot, smooth coronal loops and the concentrations of magnetic shear, known as filament channels, that reside above photospheric polarity inversion lines (PILs). The shear…
We present a three-dimensional model of rotating convection combined with a simplified corona in spherical coordinates. The motions in the convection zone generate a large-scale magnetic field that gets sporadically ejected into the outer…
Solar coronal jets are frequently occurring collimated ejections of solar plasma, originating from magnetically mixed polarity locations on the Sun of size scale comparable to that of a supergranule. Many, if not most, coronal jets are…