相关论文: Coronal loop widths and pressure scale heights

Coronal loops reveal crucial information about the nature of both coronal magnetic fields and coronal heating. The shape of the corresponding flux tube cross section and how it varies with position are especially important properties. They…

Most 1d hydrodynamic models of plasma confined to magnetic flux tubes assume circular cross-section of these tubes. We use potential field models to show that flux tubes in circumstances relevant to the solar corona do not in general…

Previous studies have found that coronal loops have a nearly uniform thickness, which seems to disagree with the characteristic expansion of active region magnetic fields. This is one of the most intriguing enigmas in solar physics. We here…

Coronal loops are plasma structures in the solar atmosphere with temperatures reaching millions of Kelvin, shaped and sustained by the magnetic field. However, their morphology and fundamental nature remain subjects of debate. By studying…

Fine-scale structure in the corona appears not to be well resolved by current imaging instruments. Assuming this to be true offers a simple geometric explanation for several current puzzles in coronal physics, including: the apparent…

Coronal loops, seen in solar coronal images, are believed to represent emission from magnetic flux tubes with compact cross-sections. We examine the 3D structure of plasma above an active region in a radiative magnetohydrodynamic simulation…

Coronal loop emission profiles are often of remarkably constant width along their entire lengths, contradicting expectations based on model coronal magnetic field strengths decreasing with height. Meanwhile Paul Bellan has produced a…

Context. Coronal loops are the basic building blocks of the solar corona, which are related to the mass supply and heating of solar plasmas in the corona. However, their fundamental magnetic structures are still not well understood. Most…

Coronal loops generally trace magnetic lines of force in the upper solar atmosphere. Understanding the loop morphology and its temporal evolution has implications for coronal heating models that rely on plasma heating due to reconnection at…

The collective transverse coronal loop oscillations seem to be detected in the observational studies. In this regard, Luna et al. (2009, ApJ, 692, 1582) modeled the collective kinklike normal modes of several cylindrical loops system using…

In coronal loop modeling, it is commonly assumed that the loops are semi-circular with a uniform cross-sectional area. However, observed loops are rarely semi-circular, and extrapolations of the magnetic field show that the field strength…

The solar corona has been revealed in the past decade to be a highly dynamic nonequilibrium plasma environment. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be strongly turbulent, but…

Loop-aligned hydrodynamic modelings help better understand the thermodynamic evolution of flaring plasma confined in solar flare loops. Conventional loop modelings typically assume a uniform loop cross section. With a variation of the cross…

Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The…

One puzzling observed property of coronal loops is that they are of roughly constant thickness along their length. Various studies have found no consistent pattern of width variation along the length of loops observed by TRACE and SOHO.…

We use a combination of analytical theory, numerical simulation, and data analysis to study the propagation of acoustic waves along coronal loops. We show that the intensity perturbation of a wave depends on a number of factors, including…

Any successful model of coronal loops must explain a number of observed properties. For warm (~ 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity…

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…

We investigate the standing kink modes of a cylindrical model of coronal loops. The density is stratified along the loop axis and changes discontinuously at the surface of the cylinder. The periods and mode profiles are studies with their…

An expansion of cross-sectional area directly impacts the mass flow along a coronal loop, and significantly alters the radiative and hydrodynamic evolution of that loop as a result. Previous studies have found that an area expansion from…