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Title: Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components

Abstract

Understanding the dynamic behavior of spicules, e.g., in terms of magnetohydrodynamic (MHD) wave mode(s), is key to unveiling their role in energy and mass transfer from the photosphere to corona. The transverse, torsional, and field-aligned motions of spicules have previously been observed in imaging spectroscopy and analyzed separately for embedded wave-mode identification. Similarities in the Doppler signatures of spicular structures for both kink and torsional Alfvén wave modes have led to the misinterpretation of the dominant wave mode in these structures and is a subject of debate. Here, we aim to combine line- of-sight (LOS) and plane-of-sky (POS) velocity components using the high spatial/temporal resolution H α imaging-spectroscopy data from the CRisp Imaging SpectroPolarimeter based at the Swedish Solar Telescope to achieve better insight into the underlying nature of these motions as a whole. The resultant three-dimensional velocity vectors and the other derived quantities (e.g., magnetic pressure perturbations) are used to identify the MHD wave mode(s) responsible for the observed spicule motion. We find a number of independent examples where the bulk transverse motion of the spicule is dominant either in the POS or along the LOS. It is shown that the counterstreaming action of the displaced external plasma duemore » to spicular bulk transverse motion has a similar Doppler profile to that of the m = 0 torsional Alfvén wave when this motion is predominantly perpendicular to the LOS. Furthermore, the inferred magnetic pressure perturbations support the kink wave interpretation of observed spicular bulk transverse motion rather than any purely incompressible MHD wave mode, e.g., the m = 0 torsional Alfvén wave.« less

Authors:
; ;  [1]
  1. Solar Physics and Space Plasma Research Centre, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)
Publication Date:
OSTI Identifier:
22663530
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 840; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALFVEN WAVES; CHROMOSPHERE; DISTURBANCES; MAGNETOHYDRODYNAMICS; MASS TRANSFER; OSCILLATIONS; PERTURBATION THEORY; PHOTOSPHERE; PLASMA; RESOLUTION; SIMULATION; SOLAR PROMINENCES; SPECTROSCOPY; SUN; TELESCOPES; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Sharma, Rahul, Verth, Gary, and Erdélyi, Robertus. Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6D57.
Sharma, Rahul, Verth, Gary, & Erdélyi, Robertus. Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components. United States. doi:10.3847/1538-4357/AA6D57.
Sharma, Rahul, Verth, Gary, and Erdélyi, Robertus. Wed . "Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components". United States. doi:10.3847/1538-4357/AA6D57.
@article{osti_22663530,
title = {Dynamic Behavior of Spicules Inferred from Perpendicular Velocity Components},
author = {Sharma, Rahul and Verth, Gary and Erdélyi, Robertus},
abstractNote = {Understanding the dynamic behavior of spicules, e.g., in terms of magnetohydrodynamic (MHD) wave mode(s), is key to unveiling their role in energy and mass transfer from the photosphere to corona. The transverse, torsional, and field-aligned motions of spicules have previously been observed in imaging spectroscopy and analyzed separately for embedded wave-mode identification. Similarities in the Doppler signatures of spicular structures for both kink and torsional Alfvén wave modes have led to the misinterpretation of the dominant wave mode in these structures and is a subject of debate. Here, we aim to combine line- of-sight (LOS) and plane-of-sky (POS) velocity components using the high spatial/temporal resolution H α imaging-spectroscopy data from the CRisp Imaging SpectroPolarimeter based at the Swedish Solar Telescope to achieve better insight into the underlying nature of these motions as a whole. The resultant three-dimensional velocity vectors and the other derived quantities (e.g., magnetic pressure perturbations) are used to identify the MHD wave mode(s) responsible for the observed spicule motion. We find a number of independent examples where the bulk transverse motion of the spicule is dominant either in the POS or along the LOS. It is shown that the counterstreaming action of the displaced external plasma due to spicular bulk transverse motion has a similar Doppler profile to that of the m = 0 torsional Alfvén wave when this motion is predominantly perpendicular to the LOS. Furthermore, the inferred magnetic pressure perturbations support the kink wave interpretation of observed spicular bulk transverse motion rather than any purely incompressible MHD wave mode, e.g., the m = 0 torsional Alfvén wave.},
doi = {10.3847/1538-4357/AA6D57},
journal = {Astrophysical Journal},
number = 2,
volume = 840,
place = {United States},
year = {Wed May 10 00:00:00 EDT 2017},
month = {Wed May 10 00:00:00 EDT 2017}
}