Damping of slow surface sausage modes in photospheric waveguides

Abstract

There has been considerable interest in sausage modes in photospheric waveguides like pores and sunspots, and slow surface sausage modes (SSSMs) have been suggested to damp ufficiently rapidly to account for chromospheric heating. Working in the framework of linear resistive magnetohydrodynamics, we examine how efficient electric resistivity and resonant absorption in the cusp continuum can be for damping SSSMs in a photospheric waveguide with equilibrium parameters compatible with recent measurements of a photospheric pore. For SSSMs with the measured wavelength, we find that the damping rate due to the cusp resonance is substantially less strong than theoretically expected with the thin-boundary approximation. The damping-time-to-period ratio ($\tau /P$) we derive for standing modes, equivalent to the damping-length-to-wavelength ratio for propagating modes given the extremely weak dispersion, can reach only $\sim 180$. However, the accepted values for electric resistivity ($\eta$) correspond to a regime where both the cusp resonance and resistivity play a role. The values for $\tau /P$ attained at the largest allowed $\eta$ may reach $\sim 30$. We conclude that electric resistivity can be considerably more efficient than the cusp resonance for damping SSSMs in the pore in question, and it needs to be incorporated into future studies on the damping of SSSMs in photospheric waveguides in general.

arXiv comment5 figures; accepted for publication in ApJ

References in corpus (21)

• Alfven Waves in the Lower Solar Atmosphere
• MHD Waves and Coronal Seismology: an overview of recent results
• Prevalence of Small-scale Jets from the Networks of the Solar Transition Region and Chromosphere
• Observations of ubiquitous compressive waves in the Sun's chromosphere
• Heating of the magnetized solar chromosphere by partial ionization effects
• Coronal Loop Oscillations Observed with AIA - Kink-Mode with Cross-Sectional and Density Oscillations
• Selective spatial damping of propagating kink waves due to resonant absorption
• Recent advances in coronal heating
• Wave Heating of the Solar Atmosphere
• ROSA: a high cadence, synchronized multi-camera solar imaging system
• Observations of sausage modes in magnetic pores
• The behavior of transverse waves in nonuniform solar flux tubes. I. Comparison of ideal and resistive results
• Heating mechanisms in the low solar atmosphere through magnetic reconnection in current sheets
• Photospheric observations of surface and body modes in solar magnetic pores
• Inferring flare loop parameters with measurements of standing sausage modes
• An Inside Look at Sunspot Oscillations with Higher Azimuthal Wavenumbers
• On the properties of slow mhd sausage waves within small-scale photospheric magnetic structures
• Resonantly Damped Kink Magnetohydrodynamic Waves in a Partially Ionized Filament Thread
• On standing sausage waves in photospheric magnetic waveguides
• Resonant absorption of surface sausage and surface kink modes under photospheric conditions
• High-frequency Oscillations in the Atmosphere above a Sunspot Umbra

Cited by in corpus (12)

• Observations of Protoplanetary Disk Structures
• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• Magnetoacoustic Wave Energy Dissipation in the Atmosphere of Solar Pores
• Resonant Damping of Kink Modes in Solar Coronal Slabs
• Damping of slow surface kink modes in solar photospheric waveguides modeled by one-dimensional inhomogeneities
• Possible Signature of Sausage Waves in Photospheric Bright Points
• Finding the mechanism of wave energy flux damping in solar pores using numerical simulations
• Propagating Slow Sausage Waves in a Sunspot Observed by the New Vacuum Solar Telescope
• Mixed properties of magnetohydrodynamic waves undergoing resonant absorption in the cusp continuum
• Oblique Quasi-Kink Modes in Solar Coronal Slabs Embedded in an Asymmetric Magnetic Environment: Resonant Damping, Phase and Group Diagrams
• Quasimodes in the cusp continuum in nonuniform magnetic flux tubes
• Stability of solar atmospheric structures harboring standing slow waves: An analytical model in a compressible plasma