Ultra-high-resolution Observations of MHD Waves in Photospheric Magnetic Structures

Abstract

Here we review the recent progress made in the detection, examination, characterisation and interpretation of oscillations manifesting in small-scale magnetic elements in the solar photosphere. This region of the Sun's atmosphere is especially dynamic, and importantly, permeated with an abundance of magnetic field concentrations. Such magnetic features can span diameters of hundreds to many tens of thousands of km, and are thus commonly referred to as the `building blocks' of the magnetic solar atmosphere. However, it is the smallest magnetic elements that have risen to the forefront of solar physics research in recent years. Structures, which include magnetic bright points, are often at the diffraction limit of even the largest of solar telescopes. Importantly, it is the improvements in facilities, instrumentation, imaging techniques and processing algorithms during recent years that have allowed researchers to examine the motions, dynamics and evolution of such features on the smallest spatial and temporal scales to date. It is clear that while these structures may demonstrate significant magnetic field strengths, their small sizes make them prone to the buffeting supplied by the ubiquitous surrounding convective plasma motions. Here, it is believed that magnetohydrodynamic waves can be induced, which propagate along the field lines, carrying energy upwards to the outermost extremities of the solar corona. Such wave phenomena can exist in a variety of guises, including fast and slow magneto-acoustic modes, in addition to Alfven waves. Coupled with rapid advancements in magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly investigate how wave motion is generated in the solar photosphere, which oscillatory modes are most prevalent, and the role that these waves play in supplying energy to various layers of the solar atmosphere.

17 pages, 7 figures, to appear as a chapter in the AGU/Wiley book "Low-frequency Waves in Space Plasmas"

References in corpus (25)

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• Alfven Waves in the Lower Solar Atmosphere
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• Observations of ubiquitous compressive waves in the Sun's chromosphere
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• Non-linear numerical simulations of magneto-acoustic wave propagation in small-scale flux tubes
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• Magnetic field strength distribution of magnetic bright points inferred from filtergrams and spectro-polarimetric data
• High-Frequency Oscillations in a Solar Active Region observed with the Rapid Dual Imager
• Observational evidence for buffeting induced kink waves in solar magnetic elements
• First evidence of interaction between longitudinal and transverse waves in solar magnetic elements
• Properties of oscillatory motions in a facular region
• The spectrum of kink-like oscillations of solar photospheric magnetic elements
• Helioseismology and Asteroseismology: Looking for Gravitational Waves in acoustic oscillations
• Solar H-alpha Oscillations from Intensity and Doppler Observations
• Nature of Quiet Sun Oscillations Using Data from the Hinode, TRACE, and SOHO Spacecraft
• Plasma properties and Stokes profiles during the lifetime of a photospheric magnetic bright point

Cited by in corpus (8)

• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• The First Ionization Potential Effect from the Ponderomotive Force: On the Polarization and Coronal Origin of the Alfven Waves
• Chromospheric Heating by MHD Waves and Instabilities
• Resonant absorption of surface sausage and surface kink modes under photospheric conditions
• Excitation of negative energy surface magnetohydrodynamic waves in an incompressible cylindrical plasma
• High-frequency oscillations in small chromospheric bright features observed with ALMA
• The effect of flow on resonant absorption of slow MHD waves in magnetic flux tubes
• The Sun at millimeter wavelengths IV. Magnetohydrodynamic waves in small-scale bright features