Related papers: Height Variations of Magnetoacoustic Cutoff Freque…
In the solar atmosphere, the acoustic cutoff frequency is a local quantity which depends on the atmospheric height. It separates the low-frequency evanescent waves from the high-frequency propagating waves. We measure the cutoff frequency…
Recently Wi\'sniewska et al. demonstrated observationally how the acoustic cutoff frequency varies with height in the solar atmosphere including the upper photosphere and the lower and middle chromosphere, and showed that the observational…
In stratified atmospheres, acoustic waves can only propagate if their frequency is above the cutoff value. Different theories provide different cutoff values. We developed an alternative method to derive the cutoff frequency in several…
We study the acoustic properties of the solar chromosphere in the high-frequency regime using a time sequence of velocity measurements in the chromospheric Ca II 854.2 nm line taken with the Interferometric Bidimensional Spectrometer…
The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value,…
We used the Pixelised Wavelet Filtering (PWF) method to compute narrow-band power maps of SDO/AIA imaging datasets in the 1700 \AA{}, 1600 \AA{} and 304 \AA{} bandpasses that correspond to different heights. The cut-off frequency was…
We investigate the oscillatory properties of the quiet solar chromosphere in relation to the underlying photosphere, with particular regard to the effects of the magnetic topology. We perform a Fourier analysis on a sequence of…
Acoustic wave heating is believed to contribute significantly to the missing energy input required to maintain the solar chromosphere in its observed state. We studied the propagation of waves above the acoustic cutoff in the upper…
Waves are an integral part of the solar atmosphere, and their characteristics (e.g., dominant period, range of periods, power, and phase angle) change on a diverse spatio-temporal scale. It is well well-established observationally that the…
Slow magnetoacoustic waves (SMAWs) have been considered in the past as a possible candidate for chromospheric heating. This study analyzes 20 active regions observed between 2012 and 2016 to examine the amplitude and energy flux variation…
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…
We present the observed local dispersion relations for magneto-acoustic-gravity waves in the Sun's atmosphere for different levels of magnetic field strength. We model these data with a theoretical local dispersion relation to produce…
We report and discuss phase-shift and phase travel time of low-frequency ({\nu} < 5.0 mHz) acoustic waves estimated within the photosphere and photosphere-chromosphere interface regions, utilizing multi-height velocities in the quiet Sun.…
Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave…
High spatial and temporal resolution images of a sunspot, obtained simultaneously in multiple optical and UV wavelengths, are employed to study the propagation and damping characteristics of slow magnetoacoustic waves up to transition…
In this work we investigate the dynamic behavior of inter-network regions of the solar chromosphere. We observed the chromosphere of the quiet Sun using a narrow-band Lyot filter centered at the Ca II K 2v emission peak with a bandpass of…
In the current analysis, we use spectroscopic observations of the quiet-Sun made by IRIS instrument, and investigate wave propagation. We analyze various spectral lines formed in different atmospheric layers such as the photosphere,…
Slow waves are commonly observed on the entire solar atmosphere. Assuming a thin flux tube approximation, the cut-off periods of slow-mode magneto-acoustic-gravity waves that travel from the photosphere to the corona were obtained in Costa…
Context. There remains much mystery about how or if wave-energy in the photosphere can be transferred sufficiently upwards through the solar atmosphere to contribute to coronal heating. In light of a plethora of theoretical and idealised…
We study vertical variations of wave-periods of magnetoacoustic two-fluid waves in the partially ionized lower solar atmosphere, consisting of ion (proton) + electron and neutral (atomic hydrogen) fluids, which are coupled by ion-neutral…