Related papers: Dynamics of Coronal-Hole Boundaries
The Sun's magnetic field is a key driver in coronal heating and consequently solar wind acceleration. Remote measurement of the photosphere provides the magnetic surface boundary condition necessary for data-constrained 3D global coronal…
High-energy particles enter the solar atmosphere from Galactic or solar coronal sources, producing an "albedo'' source from the quiet Sun, now observable across a wide range of photon energies. The interaction of high-energy particles in a…
We estimate the energy input into the solar corona from photospheric footpoint motions, using observations of a plage region by the Hinode Solar Optical Telescope. Assuming a perfectly ideal coronal evolution, two alternative lower bounds…
The origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists…
Coronal fan loops rooted in sunspot umbra show outward propagating waves with subsonic phase speed and period around 3-min. However, their source region in the lower atmosphere is still ambiguous. We performed multi-wavelength observations…
The solar corona is much hotter than the photosphere and chromosphere, but the physical mechanism responsible for heating the coronal plasma remains unidentified yet. The thermal microwave emission, which is produced in strong magnetic…
We present a method for performing data-driven simulations of solar active region formation and evolution. The approach is based on magnetofriction, which evolves the induction equation assuming the plasma velocity is proportional to the…
Accurate forecasting of the solar wind has grown in importance as society becomes increasingly dependent on technology that is susceptible to space weather events. This work describes an inner boundary condition for ambient solar wind…
The magnetic fields in the solar corona are generally neither force-free nor axisymmetric and have complex dynamics that are difficult to characterize. Here we simulate the topological evolution of solar coronal magnetic field lines (MFLs)…
Coronal rain, observed in 3D spine-fan magnetic configurations, results from thermal instability in the solar corona, where runaway in-situ cooling causes plasma to condense and drain along the magnetic lines. The reconnection of the…
Current models of the solar wind must approximate (or ignore) the small-scale dynamics within the solar atmosphere, however these are likely important in shaping the emerging wave-turbulence spectrum and ultimately heating/accelerating the…
Magnetohydrodynamic (MHD) waves and/or the braiding of magnetic field lines are largely thought to be responsible for heating the solar corona, both being mechanisms which are driven by the Sun's photospheric magnetic field. Recent…
This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also…
Extreme-ultraviolet and X-ray jets occur frequently in magnetically open coronal holes on the Sun, especially at high solar latitudes. Some of these jets are observed by white-light coronagraphs as they propagate through the outer corona…
Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…
Emanating from the base of the Sun's corona, the solar wind fills the interplanetary medium with a magnetized stream of charged particles whose interaction with the Earth's magnetosphere has space-weather consequences such as geomagnetic…
The solar atmosphere shows anomalous variation in temperature, starting from the 5500 K photosphere to the million-degree Kelvin corona. The corona itself expands into the interstellar medium as the free streaming solar wind, which…
We examine the hypothesis that ``cool loops'' dominate emission from solar transition region plasma below temperatures of $2\times10^5$K. We compare published VAULT images of H L$\alpha$, a lower transition region line, with…
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 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…