Related papers: Are Nanoflares Responsible for Coronal Heating?
The Sun continuously expels a fraction of its own mass in the form of a steadily accelerating outflow of ionized gas called the "solar wind." The solar wind is the extension of the Sun's hot (million-degree Kelvin) outer atmosphere that is…
It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…
Parker (1972) first proposed that coronal heating was the necessary outcome of an energy flux caused by the tangling of coronal magnetic field lines by photospheric flows. In this paper we discuss how this model has been modified by…
The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still today, the wind…
The relationship between observed structures in the solar atmosphere and the magnetic fields threading them is known only for the solar photosphere, even then imprecisely. We suggest that some of the fine structure in the more tenuous…
Evidence for inhomogeneous heating in the interplanetary plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only…
In the lower solar atmosphere, the chromosphere is permeated by jets known as spicules, in which plasma is propelled at speeds of 50 to 150 kilometers per second into the corona. The origin of the spicules is poorly understood, although…
Coronal structure and coronal heating are intimately related in magnetically active stars. Coronal structure is commonly inferred from radio interferometry and from eclipse and rotational modulation studies. We discuss to what extent flares…
The atmosphere of the Sun is highly structured and dynamic in nature. From the photosphere and chromosphere into the transition region and the corona plasma-$\beta$ changes from above to below one, i.e. while in the lower atmosphere the…
We simulate a coronal mass ejection (CME) using a three-dimensional magnetohydrodynamic (MHD) code that includes coronal heating, thermal conduction, and radiative cooling in the energy equation. The magnetic flux distribution at 1 R$_s$ is…
The response of the solar coronal magnetic field to small-scale photospheric boundary motions including the possible formation of current sheets via the Parker scenario is one of open questions of solar physics. Here we address the problem…
The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called coronal holes. The energy source responsible for accelerating the plasma to high speeds is widely debated, however…
We summarize our recent studies on the origin of solar wind kinetic scale turbulence and electron halo in the electron velocity distribution function. Increasing observations of nanoflares and microscopic type III radio bursts strongly…
This work consists of two parts: the first devoted to the study of the heating of the magnetically confined Solar Corona, and the second to the acceleration of the Slow Solar Wind. Direct 3D reduced MHD simulations are presented. They model…
The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…
Arch-like loop structures filled with million Kelvin hot plasma form the building blocks of the quiet-Sun corona. Both high-resolution observations and magnetoconvection simulations show the ubiquitous presence of magnetic fields on the…
We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale…
We model a coronal loop as a three-dimensional magnetic cylinder in a realistic solar atmosphere that extends from the chromosphere to the corona. Kink oscillations, believed ubiquitous in the solar corona, are launched in the loop. Heating…
The content of coronal material in the quiet Sun is not constant as soft X-ray and high-temperature EUV line observations have shown. New material, probably heated and evaporated from the chromosphere is occasionally injected even in the…
Surface magnetism is believed to be the main driver of coronal heating and stellar wind acceleration. Coronae are believed to be formed by plasma confined in closed magnetic coronal loops of the stars, with winds mainly originating in open…