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The complex dynamics that lead to the emergence of active regions on the sun are poorly understood. One possibility is that magnetic structures (flux tubes, etc.) rise from below the surface by self induction and convection that lead to the…

Solar and Stellar Astrophysics · Physics 2009-01-30 T. Hartlep , A. G. Kosovichev , J. Zhao , N. N. Mansour

An analysis of noise attenuation during eighty solar flares between 2013 and 2017 was carried out at frequencies 8-20 MHz using thirty-four SuperDARN radars and the EKB ISTP SB RAS radar. The attenuation was determined on the basis of noise…

Linear time-distance helioseismic inversions are carried out for vector flow velocities using travel times measured from two $\sim 100^2\,{\rm Mm^2}\times 20\,{\rm Mm}$ realistic magnetohydrodynamic quiet-Sun simulations of about 20 hr. The…

Solar and Stellar Astrophysics · Physics 2015-06-19 K. DeGrave , J. Jackiewicz , M. Rempel

Wave travel-time shifts in the vicinity of sunspots are typically interpreted as arising predominantly from magnetic fields, flows, and local changes in sound speed. We show here that the suppression of granulation related wave sources in a…

Astrophysics · Physics 2009-11-13 S. M. Hanasoge , S. Couvidat , S. P. Rajaguru , A. C. Birch

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Carlos Rijs , Hamed Moradi , Damien Przybylski , Paul S. Cally

Solar chromospheric observations of sunspot umbrae offer an exceptional view of magneto-hydrodynamic wave phenomena. In recent years, a wealth of wave signatures related to propagating magneto-acoustic modes have been presented, which…

The topology and dynamics of the solar chromosphere are greatly affected by the presence of magnetic fields. The magnetic field can be inferred by analyzing polarimetric observations of spectral lines. Polarimetric signals induced by…

Solar and Stellar Astrophysics · Physics 2019-09-11 C. J. Díaz Baso , J. de la Cruz Rodríguez , S. Danilovic

This work reports a novel plasma wave observation in the near-Sun solar wind: frequency-dispersed ion acoustic waves. Similar waves were previously reported in association with interplanetary shocks or planetary bow shocks, but the waves…

Solar and Stellar Astrophysics · Physics 2024-04-24 David M. Malaspina , Robert E. Ergun , Iver H. Cairns , Benjamin Short , Jaye L. Verniero , Cynthia Cattell , Roberto Livi

Previous studies analyzing the evanescent nature of acoustic waves in the lower solar atmosphere, up to 300\,km above the photosphere, have shown an unexpected phase shift of an order of 1\,s between different heights. Those studies…

Solar and Stellar Astrophysics · Physics 2023-06-14 M. Waidele , Junwei Zhao , I. N. Kitiashvili

Sunspots host a large variety of oscillatory phenomena, whose properties depend on the nature of the wave modes and the magnetic and thermodynamic structure of the spot. Umbral chromospheric oscillations exhibit significant differences…

Solar and Stellar Astrophysics · Physics 2020-07-22 T. Felipe

Studies on small-scale jets' formation, propagation, evolution, and role, such as type I and II spicules, mottles, and fibrils in the lower solar atmosphere's energetic balance, have progressed tremendously thanks to the combination of…

The interface between the bright solar surface and the million-degree corona continues to hold the key to many unsolved problems in solar physics. Advances in instrumentation now allow us to observe the dynamic structures of the solar…

Solar and Stellar Astrophysics · Physics 2019-02-13 Tiago M. D. Pereira

In this paper we refine a previously developed acoustic-source filter (Bahauddin & Rast 2021), improving its reliability and extending its capabilities. We demonstrate how to fine-tune the filter to meet observational constraints and to…

Solar and Stellar Astrophysics · Physics 2023-09-18 Shah Mohammad Bahauddin , Mark Peter Rast

The high spatial and time resolution data obtained with SDO/AIA for the sunspot in active region NOAA 11131 on 08 December 2010 were analysed with the time-distance plot technique and the pixelised wavelet filtering method. Oscillations in…

Solar and Stellar Astrophysics · Physics 2014-09-17 R. Sych , V. M. Nakariakov

Recent instrumentation has demonstrated that the solar atmosphere supports omnipresent transverse waves, which could play a key role in energizing the solar corona. Large-scale studies are required in order to build up an understanding of…

Solar and Stellar Astrophysics · Physics 2018-07-16 Micah J. Weberg , Richard J. Morton , James A. McLaughlin

We study the nature of quiet-Sun oscillations using multi-wavelength observations from TRACE, Hinode, and SOHO. The aim is to investigate the existence of propagating waves in the solar chromosphere and the transition region via analyzing…

Solar and Stellar Astrophysics · Physics 2012-09-27 G. R. Gupta , S. Subramanian , D. Banerjee , M. S. Madjarska , J. G. Doyle

A number of recent investigations have revealed that transverse waves are ubiquitous in the solar chromosphere. The vast majority of these have been reported in limb spicules and active region fibrils. We investigate long-lived, quiet Sun,…

Solar and Stellar Astrophysics · Physics 2015-06-04 D. Kuridze , R. J. Morton , R. Erdélyi , G. D. Dorrian , M. Mathioudakis , D. B. Jess , F. P. Keenan

The determination of the cutoff frequency in real solar observations under different local physical conditions is an important and insufficiently explored aspect of waves in solar physics. This work utilizes the near ultraviolet (NUV)…

Solar and Stellar Astrophysics · Physics 2026-05-14 Pradeep Kayshap , Gayathri Hegde , Z. E. Musielak , Kris Murawski , Tobıas Felipe

This paper aims to reconstruct the internal structure of a two-dimensional test object via numerically simulated full-wave time domain radar tomography with the presence of wavelength-induced (WI) uncertainties, following from a complex…

Earth and Planetary Astrophysics · Physics 2022-07-06 Yusuf Oluwatoki Yusuf , Astrid Dufaure , Liisa-Ida Sorsa , Christelle Eyraud , Sampsa Pursiainen

Sound waves are attenuated as they propagate in amorphous materials. We investigate the mechanism driving sound attenuation in the Rayleigh scattering regime by resolving the dynamics of an excited phonon in time and space via numerical…

Soft Condensed Matter · Physics 2024-01-18 Shivam Mahajan , Massimo Pica Ciamarra