Related papers: Multi-layer study of wave propagation in sunspots
Context. In previous work, we studied a prominence which appeared like a tornado in a movie made from 193 {\AA} filtergrams obtained with the Atmospheric Imaging Assembly (AIA) imager aboard the Solar Dynamics Observatory (SDO). The…
On 12 March 1996 we obtained observations of the quiet Sun with the SUMER instrument. The observa- tions were sequences of 15-20 second exposures of ultraviolet emission line profiles and of the neighboring continua. These data contain…
Velocity gradients in a stellar atmospheric plasma have an impact on the anisotropy of the radiation field that illuminates each point within the medium, and this may in principle influence the scattering line polarization that results from…
We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magneto-hydrodynamic code, respectively. Each dataset demonstrates a…
Magnetohydrodynamic (MHD) waves have been considered as energy sources for heating the solar chromosphere and the corona. Although MHD waves have been observed in the solar atmosphere, there are a lack of quantitative estimates on the…
The Mg II h and k lines are among the strongest in the near-ultraviolet solar spectrum and their line core originates in the upper chromosphere, just below the transition region. Consequently, they have become one of the main targets for…
Ca {\sc i} 4227 \AA\, line is a strong resonance line formed in the Solar chromosphere. At the limb, it produces the largest scattering polarization signal. So far, modeling the linear polarization in this line has been limited to the use…
I review the literature on observational aspects of waves in the solar chromosphere in the first part of this contribution. High-frequency waves are invoked to build elaborate cool-star chromosphere heating theories but have not been…
Gravity waves are generated by turbulent subsurface convection overshooting or penetrating locally into a stably stratified medium. While propagating energy upwards, their characteristic negative phase shift over height is a well-recognized…
The Chromospheric LAyer SpectroPolarimeter missions, CLASP2 and CLASP2.1, demonstrated that the near-UV spectral region between 279.30 and 280.68 nm is suitable for studying the magnetism of the solar chromosphere. In particular, the…
High-frequency waves (5 mHz to 20mHz) have previously been suggested as a source of energy accounting partial heating of the quiet solar atmosphere. The dynamics of previously detected high-frequency waves is analysed here. Image sequences…
We observe and characterize the scattering of acoustic wave packets by a sunspot, in a regime where the wavelength is comparable to the size of the sunspot. Spatial maps of wave traveltimes and amplitudes are measured from the…
Acoustic waves and pulses propagating from the solar photosphere upwards may quickly develop into shocks due to the rapid decrease of atmospheric density. However, if they propagate along a magnetic flux tube, then the nonlinear steepening…
This is a theoretical investigation on the formation of the linearly polarized line spectrum of ionized cerium in the sun. We calculate the scattering line polarization pattern emergent from a plane-parallel layer of Ce {\sc ii} atoms…
We study the circular polarization of the Mn I resonance lines at 279.56, 279.91, and 280.19 nm (hereafter, UV multiplet) by means of radiative transfer modeling. In 2019, the CLASP2 mission obtained unprecedented spectropolarimetric data…
Using high cadence observations from the Hydrogen-alpha Rapid Dynamics camera imaging system on the Dunn Solar Telescope, we present an investigation of the statistical properties of transverse oscillations in spicules captured above the…
The structure and energy balance of the solar chromosphere remain poorly known. We have used the imaging spectrometer IBIS at the Dunn Solar Telescope to obtain fast-cadence, multi-wavelength profile sampling of Halpha and Ca II 854.2 nm…
The subject of this study is oscillations in the lower atmosphere in coronal-hole regions, where the conditions are favorable for propagation between the atmospheric layers. Based on spectroscopic observations in photospheric and…
Context. The height structure of 3-min oscillations over sunspots is studied in the context of the recently discovered effect of height inversion: over the umbra, the spatial location of the maximum of chromospheric 3-min oscillation power…
Flare ribbons are bright manifestations of flare energy dissipation in the lower solar atmosphere. For the first time, we report on high-resolution imaging spectroscopy observations of flare ribbons situated off-limb in the H$\beta$ and Ca…