The heating of the lower solar corona is examined using numerical simulations and theoretical models of magnetohydrodynamic turbulence in open magnetic regions. A turbulent energy cascade to small length scales perpendicular to the mean magnetic field can be sustained by driving with low-frequency Alfvén waves reflected from mean density and magnetic field gradients. This mechanism deposits ene...

Observations of type II radio bursts and energetic electron events indicate that shocks can form at 1Y3 solar radii and are responsible for the GeV nucleon 1 energies observed in ground level solar energetic particle (SEP) events. Here we provide the first study of the lower corona produced from 10 state-of-the-art models. In particular, we look to the Alfvén speed profiles as the criterion for...

In paper I, we showed that time-dependent general relativistic magnetohydrodynamic (GRMHD) numerical models of accretion disks, although being highly turbulent, have surprisingly simple electromagnetic properties. In particular, the toroidal current density in the disk takes the form dIφ/dr ∝ r . Guided by this simplicity, we use a time-dependent general relativistic force-free electrodynamics ...

Understanding and monitoring the solar corona and solar wind is important for many applications like telecommunications or geomagnetic studies. Coronal electron density models have been derived by various techniques over the last 45 years, principally by analysing the effect of the corona on spacecraft tracking. Here we show that recent observational data from very long baseline interferometry ...

In paper I, we showed that time-dependent general relativistic magnetohydrodynamic (GRMHD) numerical models of accretion disks, although being highly turbulent, have surprisingly simple electromagnetic properties. In particular, the toroidal current density in the disk takes the form dIφ/dr ∝ r . Guided by this simplicity, we use a time-dependent general relativistic force-free electrodynamics ...

This paper is aimed at proposing a new design of a corona-discharge based electrostatic motor with a cylindrical rotor made from aluminum foil and multi copper strip stator electrodes. The stator electrodes are alternately stressed positively and negatively. The onset voltage of corona discharge is calculated based on the condition of discharge sustenance at stator electrodes. The corona curren...

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 direct observational evidence for a cascade of fluctuation energy from large to small scales is lacking. In this paper I will review the observations of waveli...

The deposition of energy into the solar wind beyond 1 AU is thought to result from the dissipation of low frequency magnetohydrodynamic (MHD) turbulence via kinetic processes at spatial scales comparable to the ion gyroradius. Beyond 1 AU, solar wind turbulence is comprised of both a decaying component generated in the corona and turbulence generated dynamically in situ by processes such as str...

We construct subsynoptic maps of the ultraviolet-line fluxes, electron density, and elemental abundances for an east limb corona at 1.63 solar radii from 2000 September 20 to October 1. The data, covering position angles of 85 Y126 , were taken from the Ultraviolet Coronagraph Spectrometer (UVCS) on board the Solar and Heliospheric Observatory (SOHO), and the maps are based on the variation of ...

We present a new model for the coronal structure of rapidly rotating solar-type stars. The presence of prominences trapped in co-rotation 2 to 5 stellar radii above the stellar surface has been taken as evidence that the coronae of these stars must be very extended. The observed surface magnetic fields, however, cannot contain Xray emitting gas out to these distances. We present an alternative ...