相关论文: Solar off-limb line widths: Alfven waves, ion-cycl…

(abridged) We investigate how the properties of the corona and solar wind in the open coronal holes depend on the properties of the magnetic fields and their footpoint motions at the surface, by perfoming 1D MHD simulations from the…

State-of-the-art MHD calculations reveal acceptable agreement with observational data for the height profile of the temperature $T(h)$ in the transition region of solar corona. Simultaneously, the velocity of the solar wind $U(h)$ has also…

Remote sensing observations of coronal holes show that heavy ions are hotter than protons and their temperature is anisotropic. In-situ observations of fast solar wind streams provide direct evidence for turbulent Alfv\'en wave spectrum,…

The nonthermal broadening of spectral lines formed in the solar corona is often used to seek the evidence of Alfv\'en waves propagating in the corona. To have a better understanding of the variation of line widths at different altitudes, we…

In the solar atmosphere, the chromospheric and coronal plasmas are much hotter than the visible photosphere. The heating of the solar atmosphere, including the partially ionized chromosphere and corona, remains largely unknown. In this…

It is now well established that the Alfv\'enic waves are ubiquitous in the solar corona. However, the Alfv\'enic wave energy estimated from the Doppler velocity measurements in the corona was found to be four orders of magnitude less than…

In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures,…

Although the origins of slow solar wind are unclear, there is increasing evidence that at least some of it is released in a steady state on over-expanded coronal hole magnetic field lines. This type of slow wind has similar properties to…

We study the impulsively generated non-linear Alfv\'en waves in the solar atmosphere, and describe their most likely role in the observed non-thermal broadening of some spectral lines in solar coronal holes. We solve numerically the…

The discovery of ubiquitous low-frequency (3-5mHz) Alfvenic waves in the solar chromosphere (with Hinode/SOT), and corona (with CoMP and the Solar Dynamics Observatory, SDO) has provided some insight into the non-thermal energy content of…

The solar ultraviolet intensities of spectral lines originating from Li- and Na-like ions have been observed to surpass the expectations derived from plasmas with coronal approximation. The violation of the coronal approximation can be…

We present a new version of the Alfven Wave Solar Model (AWSoM), a global model from the upper chromosphere to the corona and the heliosphere. The coronal heating and solar wind acceleration are addressed with low-frequency Alfven wave…

Solar extreme-ultraviolet (EUV) lines emitted by highly charged ions have been extensively studied to discuss the issue of coronal heating and solar wind acceleration. Based on observations of the polar corona by the SUMER/SOHO…

Images taken in the band centered at 30.4 nm are routinely used to map the radiance of the He II Ly alpha line on the solar disk. That line is one of the strongest, if not the strongest, line in the EUV observed in the solar spectrum, and…

Protons in the solar corona and heliosphere exhibit anisotropic velocity distributions, violation of magnetic moment conservation, and a general lack of thermal equilibrium with the other particle species. There is no agreement about the…

The extreme temperatures and non-thermal nature of the solar corona and solar wind arise from an unidentified physical mechanism that preferentially heats certain ion species relative to others. Spectroscopic indicators of unequal…

Observations reveal an increase with height of the line width of several coronal spectral lines probably caused by outwardly propagating Alfv{\'e}n waves. However, the spectral line width sometimes shows a sudden decrease at a height…

We have measured the energy and dissipation of Alfvenic waves in the quiet Sun. A magnetic field was used to infer the location and orientation of the magnetic field lines along which the waves are expected to travel. The waves were…

It is shown that in low-beta, weakly collisional plasmas, such as the solar corona, some instances of the solar wind, the aurora, inner regions of accretion discs, their coronae, and some laboratory plasmas, Alfv\'enic fluctuations produce…

In the context of coronal heating, among the zoo of MHD waves that exist in the solar atmosphere, Alfven waves receive special attention. Indeed, these waves constitute an attractive heating agent due to their ability to carry over the many…