Related papers: Measurements on the kinetic physics in streamer dy…
The first two orbits of the Parker Solar Probe (PSP) spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 Rs). Here, we present an analysis of this data to study solar…
The heating and structure of the solar chromosphere depends on the underlying magnetic field, among other parameters. The lowest magnetic flux of the solar atmosphere is found in the quiet Sun internetwork and is thought to be provided by…
Differential flows among different ion species are often observed in the solar wind, and such ion differential flows can provide the free energy to drive Alfv\'en/ion-cyclotron and fast-magnetosonic/whistler instabilities. Previous works…
The review presents analysis and physical interpretation of available statistical data about solar wind plasma and interplanetary magnetic field (IMF) properties as measured in-situ at 1 A.U. by numerous space experiments during time period…
The heating of the solar wind is a key to understand its dynamics and acceleration process. The observed radial decrease of proton temperature in the solar wind is slow compared to the adiabatic prediction and it is thought to be caused by…
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…
We report experimental observations of a controlled transition from a zonal-flow (ZF) dominated regime to a coexistence regime of ZFs and streamers, and finally to a streamer-dominated state in a linear magnetized plasma column. The…
During Parker Solar Probe (Parker) Encounter 15 (E15), we observe an 18-hour period of near subsonic ($\mathrm{M_S \sim}$ 1) and sub-Alfv\'enic (SA), $\mathrm{M_A}$ <<< 1, slow speed solar wind from 22 to 15.6 R$_\odot$. As the most extreme…
The solar wind is highly structured in fast and slow flows. These two dynamical regimes remarkably differ not only for the average values of magnetic field and plasma parameters but also for the type of fluctuations they transport. Fast…
The means by which the turbulent cascade of energy is dissipated in the solar wind, and in other astrophysical systems, is a major open question. It has recently been proposed that a barrier to the transfer of energy can develop at small…
We study radio emissions from positive streamers in air using 3D simulations, from which the radiated electric field is computed by solving Jefimenko's equations. The simulations are performed at 0.5 bar using two photoionization methods:…
Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for…
This letter describes a new phenomenon on the Parker Solar Probe of recurring plasma density enhancements that have $\Delta$n/n ~10% and that occur at a repetition rate of ~5 Hz. They were observed sporadically for about five hours between…
We present numerical modelling of particle acceleration at coronal shocks propagating through a streamer-like magnetic field by solving the Parker transport equation with spatial diffusion both along and across the magnetic field. We show…
The elemental composition of the Sun's hot atmosphere, the corona, shows a distinctive pattern that is different than the underlying surface, or photosphere (Pottasch 1963). Elements that are easy to ionize in the chromosphere are enhanced…
The plasma-$\beta$ is an important fundamental physical quantity in solar plasma physics, which determines the dominating process in the solar atmosphere, i.e., magnetic or thermodynamic processes. Here, for the first time, we provide…
In-situ observations of the solar wind (SW) plasma from 0.29 to 1AU show that the protons and alpha particles are often non-Maxwellian, with evidence of kinetic instabilities, temperature anisotropies, differential ion streaming, and…
Empirical solar wind speed models play an important role in enabling space weather forecasting with low computational cost. Among these, one model called WS model is based on the asymptotic expansion factor. However, it is known that it…
In this review we describe a transient type of gas discharge which is commonly called a streamer discharge, as well as a few related phenomena in pulsed discharges. Streamers are propagating ionization fronts with self-organized field…
Streamer discharges are often operated in a repetitively pulsed mode and are therefore influenced by species left over from the previous discharge, especially free electrons and ions. We have investigated these effects by applying two…