ALFVÉN INSTABILITY IN CORONAL LOOPS WITH SIPHON FLOWS
نویسندگان
چکیده
منابع مشابه
Numerical simulations of kink instability in line-tied coronal Loops
The results from numerical simulations carried out using a new shock-capturing, Lagrangian-remap, 3D MHD code, Lare3d are presented. We study the evolution of the m = 1 kink mode instability in a photospherically line-tied coronal loop that has no net axial current. During the non-linear evolution of the kink instability, large current concentrations develop in the neighbourhood of the infinite...
متن کاملAlfvén instability in a compressible flow.
A new ideal magnetohydrodynamic instability is presented. It is shown that linear incompressible Alfvénic disturbances can get over-reflected and exponentially amplified in compressible plasma flows. A simple and transparent stability criterion for a two-layer model is derived. The instability does not require a shear in the flow and may arise for rather moderate sub-Alfvénic flow speeds. It is...
متن کاملPhysics of Coronal Loops
Coronal loops are the basic elements of the solar corona and are responsible for the totality of the coronal X-ray emission. Loop physics is therefore important to understand the structure, heating, dynamics and evolution of the corona. A well-established and useful approach to study loop physics has been the detailed hydrodynamic modeling of the connned plasma, coupled to the synthesis of obse...
متن کاملCoronal Alfvén speeds in an isothermal atmosphere I . Global properties
Aims. Estimating Alfvén speeds is of interest in modelling the solar corona, studying the coronal heating problem and understanding the initiation and propagation of coronal mass ejections (CMEs). Methods. We assume here that the corona is in a magnetohydrostatic equilibrium and that, because of the low plasma β, one may decouple the magnetic forces from pressure and gravity. The magnetic field...
متن کاملModels of Dynamic Coronal Loops
This paper reviews the basic ideas underlying one-dimensional uid dynamic models of coronal loops and presents some of their most recent applications. These models are an important theoretical support to explore the new scenario provided by the data of Yohkoh, SOHO and TRACE, and are useful to interpret observations, when supplemented by appropriate spectral synthesis codes. Possible developmen...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2009
ISSN: 0004-637X,1538-4357
DOI: 10.1088/0004-637x/694/1/69