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Title: Dynamics of Coronal Hole Boundaries

Abstract

Remote and in situ observations strongly imply that the slow solar wind consists of plasma from the hot, closed-field corona that is released onto open magnetic field lines. The Separatrix Web theory for the slow wind proposes that photospheric motions at the scale of supergranules are responsible for generating dynamics at coronal-hole boundaries, which result in the closed plasma release. We use three-dimensional magnetohydrodynamic simulations to determine the effect of photospheric flows on the open and closed magnetic flux of a model corona with a dipole magnetic field and an isothermal solar wind. A rotational surface motion is used to approximate photospheric supergranular driving and is applied at the boundary between the coronal hole and helmet streamer. The resulting dynamics consist primarily of prolific and efficient interchange reconnection between open and closed flux. The magnetic flux near the coronal-hole boundary experiences multiple interchange events, with some flux interchanging over 50 times in one day. Additionally, we find that the interchange reconnection occurs all along the coronal-hole boundary and even produces a lasting change in magnetic-field connectivity in regions that were not driven by the applied motions. Our results show that these dynamics should be ubiquitous in the Sun and heliosphere.more » We discuss the implications of our simulations for understanding the observed properties of the slow solar wind, with particular focus on the global-scale consequences of interchange reconnection.« less

Authors:
;  [1]; ;  [2];  [3]
  1. Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)
  2. Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  3. Universities Space Research Association, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22661304
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 837; 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; APPROXIMATIONS; DIPOLES; HELIOSPHERE; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETIC RECONNECTION; MAGNETOHYDRODYNAMICS; PLASMA; SOLAR WIND; SUN; SURFACES; THREE-DIMENSIONAL CALCULATIONS

Citation Formats

Higginson, A. K., Zurbuchen, T. H., Antiochos, S. K., DeVore, C. R., and Wyper, P. F. Dynamics of Coronal Hole Boundaries. United States: N. p., 2017. Web. doi:10.3847/1538-4357/837/2/113.
Higginson, A. K., Zurbuchen, T. H., Antiochos, S. K., DeVore, C. R., & Wyper, P. F. Dynamics of Coronal Hole Boundaries. United States. doi:10.3847/1538-4357/837/2/113.
Higginson, A. K., Zurbuchen, T. H., Antiochos, S. K., DeVore, C. R., and Wyper, P. F. Fri . "Dynamics of Coronal Hole Boundaries". United States. doi:10.3847/1538-4357/837/2/113.
@article{osti_22661304,
title = {Dynamics of Coronal Hole Boundaries},
author = {Higginson, A. K. and Zurbuchen, T. H. and Antiochos, S. K. and DeVore, C. R. and Wyper, P. F.},
abstractNote = {Remote and in situ observations strongly imply that the slow solar wind consists of plasma from the hot, closed-field corona that is released onto open magnetic field lines. The Separatrix Web theory for the slow wind proposes that photospheric motions at the scale of supergranules are responsible for generating dynamics at coronal-hole boundaries, which result in the closed plasma release. We use three-dimensional magnetohydrodynamic simulations to determine the effect of photospheric flows on the open and closed magnetic flux of a model corona with a dipole magnetic field and an isothermal solar wind. A rotational surface motion is used to approximate photospheric supergranular driving and is applied at the boundary between the coronal hole and helmet streamer. The resulting dynamics consist primarily of prolific and efficient interchange reconnection between open and closed flux. The magnetic flux near the coronal-hole boundary experiences multiple interchange events, with some flux interchanging over 50 times in one day. Additionally, we find that the interchange reconnection occurs all along the coronal-hole boundary and even produces a lasting change in magnetic-field connectivity in regions that were not driven by the applied motions. Our results show that these dynamics should be ubiquitous in the Sun and heliosphere. We discuss the implications of our simulations for understanding the observed properties of the slow solar wind, with particular focus on the global-scale consequences of interchange reconnection.},
doi = {10.3847/1538-4357/837/2/113},
journal = {Astrophysical Journal},
number = 2,
volume = 837,
place = {United States},
year = {Fri Mar 10 00:00:00 EST 2017},
month = {Fri Mar 10 00:00:00 EST 2017}
}