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We present results on modeling solar pores and sunspots using 2D axisymmetric magneto-hydrodynamic (MHD) simulations. These models are helpful for understanding the mechanisms of magnetic field concentration in sunspots, and the large-scale…

Solar and Stellar Astrophysics · Physics 2010-06-22 T. Hartlep , F. H. Busse , N. E. Hulburt , A. G. Kosovichev

Accurate and efficient plasma models are essential to understand and control experimental devices. Existing magnetohydrodynamic or kinetic models are nonlinear, computationally intensive, and can be difficult to interpret, while often only…

Plasma Physics · Physics 2020-03-04 Alan A. Kaptanoglu , Kyle D. Morgan , Chris J. Hansen , Steven L. Brunton

Magnetohydrodynamic (MHD) waves, playing a crucial role in transporting energy through the solar atmosphere, manifest in various chromospheric structures. Here, we investigated MHD waves in a long-lasting dark fibril using…

Solar and Stellar Astrophysics · Physics 2024-12-25 Maryam Saberi , Shahin Jafarzadeh , Sven Wedemeyer , Ricardo Gafeira , Mikolaj Szydlarski , David Jess , Marco Stangalini

Umbral dots (UDs) are small-scale convective intrusions in the umbral core of sunspots and pores. Different methods have been used in the past to determine the physical properties of UDs. One of the methods typically used is multi-level…

Solar and Stellar Astrophysics · Physics 2026-05-27 Rohan Eugene Louis , Amit Chaturvedi

Over the past number of years, great strides have been made in identifying the various low-order magnetohydrodynamic wave modes observable in a number of magnetic structures found within the solar atmosphere. However, one aspect of these…

Umbral dots (UDs) were observed in a stable sunspot in NOAA 10944 by the Hinode Solar Optical Telescope on 2007 March 1. The observation program consisted of blue continuum images and spectropolarimetric profiles of Fe I 630 nm line. An…

Solar and Stellar Astrophysics · Physics 2015-05-13 Hiroko Watanabe , Reizaburo Kitai , Kiyoshi Ichimoto

The propagation of solar waves through the sunspot of AR 9787 is observed using temporal cross-correlations of SOHO/MDI Dopplergrams. We then use three-dimensional MHD numerical simulations to compute the propagation of wave packets through…

Astrophysics · Physics 2009-11-13 R. Cameron , L. Gizon , T. L. Duvall

MHD waves are ubiquitous in the solar corona where the highly structured magnetic fields provide efficient wave guides for their propagation. While MHD waves have been observed originating from lower layers of the solar atmosphere, recent…

Solar and Stellar Astrophysics · Physics 2019-06-12 P. Pagano , H. J. Van Damme , P. Antolin , I. De Moortel

Sunspots on the surface of the Sun are the observational signatures of intense manifestations of tightly packed magnetic field lines, with near-vertical field strengths exceeding 6,000 G in extreme cases. It is well accepted that both the…

Umbral dots (UDs) are transient, bright features observed in the umbral region of a sunspot. We study the physical properties of UDs observed in sunspots of different sizes. The aim of our study is to relate the physical properties of…

Solar and Stellar Astrophysics · Physics 2018-03-14 Rahul Yadav , Rohan E. Louis , Shibu K. Mathew

Data-driven decompositions are becoming essential tools in fluid dynamics, allowing for tracking the evolution of coherent patterns in large datasets, and for constructing low order models of complex phenomena. In this work, we analyze the…

Fluid Dynamics · Physics 2020-04-15 M. A. Mendez , M. Balabane , J. -M. Buchlin

We demonstrate the application of the Dynamic Mode Decomposition (DMD) for the diagnostic analysis of the nonlinear dynamics of a magnetized plasma in resistive magnetohydrodynamics. The DMD method is an ideal spatio-temporal matrix…

Plasma Physics · Physics 2018-05-23 Roy Taylor , J. Nathan Kutz , Kyle Morgan , Brian Nelson

Modal decomposition methods are important for characterizing the low-dimensional dynamics of complex systems, including turbulent flows. Different methods have varying data requirements and produce modes with different properties. Spectral…

Fluid Dynamics · Physics 2025-08-28 Caroline Cardinale , Steven L. Brunton , Tim Colonius

Magnetohydrodynamic (MHD) kink waves are ubiquitously observed in the solar atmosphere. The propagation and damping of these waves may play relevant roles for the transport and dissipation of energy in the solar atmospheric medium. However,…

Solar and Stellar Astrophysics · Physics 2015-06-23 Roberto Soler , Jaume Terradas

Modal decomposition techniques are showing a fast growth in popularity for their good properties as data-driven tools. There are several modal decomposition techniques, yet Proper Orthogonal Decomposition (POD) and Dynamic Mode…

In November 2021, Solar Orbiter started its nominal mission phase. The remote-sensing instruments on board the spacecraft acquired scientific data during three observing windows surrounding the perihelion of the first orbit of this phase.…

The modal decomposition techniques of proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) have become a common method for analysing the spatio-temporal coherence of dynamical systems. In particular, these techniques…

Fluid Dynamics · Physics 2019-09-18 Scott B. Leask , Vincent G. McDonell

Recent observations by Hinode/SOT show that MHD waves and mass flows are simultaneously present in the fine structure of solar prominences. We investigate standing kink magnetohydrodynamic (MHD) waves in flowing prominence threads from a…

Solar and Stellar Astrophysics · Physics 2015-05-28 Roberto Soler , Marcel Goossens

Given the recent interest in magnetohydrodynamic (MHD) waves in pores and sunspot umbrae, we examine the damping of slow surface kink modes (SSKMs) by modeling solar photospheric waveguides with a cylindrical inhomogeneity comprising a…

Solar and Stellar Astrophysics · Physics 2021-03-03 Shao-Xia Chen , Bo Li , Tom Van Doorsselaere , Marcel Goossens , Hui Yu , Michael Geeraerts

We present a Bayesian seismology inversion technique for propagating magnetohydrodynamic (MHD) transverse waves observed in coronal waveguides. The technique uses theoretical predictions for the spatial damping of propagating kink waves in…

Solar and Stellar Astrophysics · Physics 2015-06-15 I. Arregui , A. Asensio Ramos , D. J. Pascoe