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Title: CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE

Abstract

It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this Letter, we investigate the high solar dynamic activity in the declining phase of the sunspot cycle by examining the evolution of polar and low-latitude coronal hole (CH) areas, splitting and merging events of CHs, and coronal mass ejections (CMEs) detected by SOHO /LASCO C3 in solar cycle 23. Although the total CH area is at its maximum near the sunspot minimum, in which polar CHs prevail, it shows a comparable second maximum in the declining phase of the cycle, in which low-latitude CHs are dominant. The events of CH splitting or merging, which are attributed to surface motions of magnetic fluxes, are also mostly populated in the declining phase of the cycle. The far-reaching C3 CMEs are also overpopulated in the declining phase of the cycle. From these results we suggest that solar dynamic activities due to the horizontal surface motions of magnetic fluxes extend far in the declining phase of the sunspot cycle.

Authors:
;  [1];  [2];  [3]
  1. Department of Astronomy and Space Science, Kyung Hee University, Yongin 17104 (Korea, Republic of)
  2. Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States)
  3. School of Space Research, Kyung Hee University, Yongin 17104 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22654142
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 833; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; EVOLUTION; MAGNETIC FIELDS; MAGNETIC FLUX; MASS; SOLAR CORONA; SOLAR CYCLE; SUN; SUNSPOTS; SURFACES

Citation Formats

Jang, Minhwan, Choe, G. S., Woods, T. N., and Hong, Sunhak. CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE. United States: N. p., 2016. Web. doi:10.3847/2041-8213/833/1/L11.
Jang, Minhwan, Choe, G. S., Woods, T. N., & Hong, Sunhak. CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE. United States. https://doi.org/10.3847/2041-8213/833/1/L11
Jang, Minhwan, Choe, G. S., Woods, T. N., and Hong, Sunhak. 2016. "CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE". United States. https://doi.org/10.3847/2041-8213/833/1/L11.
@article{osti_22654142,
title = {CORONAL DYNAMIC ACTIVITIES IN THE DECLINING PHASE OF A SOLAR CYCLE},
author = {Jang, Minhwan and Choe, G. S. and Woods, T. N. and Hong, Sunhak},
abstractNote = {It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this Letter, we investigate the high solar dynamic activity in the declining phase of the sunspot cycle by examining the evolution of polar and low-latitude coronal hole (CH) areas, splitting and merging events of CHs, and coronal mass ejections (CMEs) detected by SOHO /LASCO C3 in solar cycle 23. Although the total CH area is at its maximum near the sunspot minimum, in which polar CHs prevail, it shows a comparable second maximum in the declining phase of the cycle, in which low-latitude CHs are dominant. The events of CH splitting or merging, which are attributed to surface motions of magnetic fluxes, are also mostly populated in the declining phase of the cycle. The far-reaching C3 CMEs are also overpopulated in the declining phase of the cycle. From these results we suggest that solar dynamic activities due to the horizontal surface motions of magnetic fluxes extend far in the declining phase of the sunspot cycle.},
doi = {10.3847/2041-8213/833/1/L11},
url = {https://www.osti.gov/biblio/22654142}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 833,
place = {United States},
year = {Sat Dec 10 00:00:00 EST 2016},
month = {Sat Dec 10 00:00:00 EST 2016}
}