Chromospheric Heating by Magnetohydrodynamic Waves and Instabilities

Magnetohydrodynamic Waves and Instabilities in Homogeneous Gyrotropic Ultrarelativistic Plasma

In some astrophysical systems the ionized gas may be of such high temperature and so strongly magnetized that relativistic effects and pressure anisotropy must be considered in the magnetohydrodynamic (MHD) model. This paper gives an overview of the characteristics of linear MHD waves and instabilities in homogeneous ultrarelativistic plasmas with gyrotropic pressure. The energy closure is the ...

Issn 1845–8319 an Estimate of Chromospheric Heating by Acoustic Waves

Several mechanisms may heat the solar chromosphere: acoustic waves, magnetoacoustic waves (slow, fast, and Alfvén waves), and small-scale magnetic reconnections. Based on observations in the Ca II 854.2 nm line, the contribution of acoustic waves to the heating of quiet and plage regions in the chromosphere is discussed. The energy released by radiative losses is compared with the energy deposi...

Coronal heating by resonant absorption: the effects of chromospheric coupling

Magnetohydrodynamic Shearing Waves

I consider the nonaxisymmetric linear theory of an isothermal magnetohydrodynamic (MHD) shear flow. The analysis is performed in the shearing box, a local model appropriate for a thin disk geometry. Linear perturbations in this model can be decomposed in terms of shearing waves (shwaves), which appear spatially as plane waves in a frame comoving with the shear. The time dependence of these wave...

Giant Chromospheric Anemone Jet observed with Hinode and Comparison with Magnetohydrodynamic Simulations: Evidence of Propagating Alfvén Waves and Magnetic Reconnection

Hinode discovered a beautiful giant jet with both cool and hot components at the solar limb on 2007 February 9. Simultaneous observations by the Hinode SOT, XRT, and TRACE 195 Å satellites revealed that hot (∼ 5 × 10 K) and cool (∼ 10 K) jets were located side by side and that the hot jet preceded the associated cool jet (∼ 1 − 2 min.). A current-sheet-like structure was seen in optical (Ca II ...