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Title: WHY IS THE GREAT SOLAR ACTIVE REGION 12192 FLARE-RICH BUT CME-POOR?

Abstract

Solar active region (AR) 12192 of 2014 October hosts the largest sunspot group in 24 years. It is the most prolific flaring site of Cycle 24 so far, but surprisingly produced no coronal mass ejection (CME) from the core region during its disk passage. Here, we study the magnetic conditions that prevented eruption and the consequences that ensued. We find AR 12192 to be “big but mild”; its core region exhibits weaker non-potentiality, stronger overlying field, and smaller flare-related field changes compared to two other major flare-CME-productive ARs (11429 and 11158). These differences are present in the intensive-type indices (e.g., means) but generally not the extensive ones (e.g., totals). AR 12192's large amount of magnetic free energy does not translate into CME productivity. The unexpected behavior suggests that AR eruptiveness is limited by some relative measure of magnetic non-potentiality over the restriction of background field, and that confined flares may leave weaker photospheric and coronal imprints compared to their eruptive counterparts.

Authors:
; ; ; ; ;  [1]; ;  [2];  [3]
  1. W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States)
  2. Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States)
  3. School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026 (China)
Publication Date:
OSTI Identifier:
22518982
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 804; Journal Issue: 2; 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; FREE ENERGY; MAGNETIC FIELDS; MASS; PHOTOSPHERE; PRODUCTIVITY; SOLAR CORONA; SOLAR FLARES; SUN; SUNSPOTS

Citation Formats

Sun, Xudong, Bobra, Monica G., Hoeksema, J. Todd, Liu, Yang, Couvidat, Sebastien, Norton, Aimee A., Li, Yan, Fisher, George H., and Shen, Chenglong, E-mail: xudong@Sun.stanford.edu. WHY IS THE GREAT SOLAR ACTIVE REGION 12192 FLARE-RICH BUT CME-POOR?. United States: N. p., 2015. Web. doi:10.1088/2041-8205/804/2/L28.
Sun, Xudong, Bobra, Monica G., Hoeksema, J. Todd, Liu, Yang, Couvidat, Sebastien, Norton, Aimee A., Li, Yan, Fisher, George H., & Shen, Chenglong, E-mail: xudong@Sun.stanford.edu. WHY IS THE GREAT SOLAR ACTIVE REGION 12192 FLARE-RICH BUT CME-POOR?. United States. doi:10.1088/2041-8205/804/2/L28.
Sun, Xudong, Bobra, Monica G., Hoeksema, J. Todd, Liu, Yang, Couvidat, Sebastien, Norton, Aimee A., Li, Yan, Fisher, George H., and Shen, Chenglong, E-mail: xudong@Sun.stanford.edu. Sun . "WHY IS THE GREAT SOLAR ACTIVE REGION 12192 FLARE-RICH BUT CME-POOR?". United States. doi:10.1088/2041-8205/804/2/L28.
@article{osti_22518982,
title = {WHY IS THE GREAT SOLAR ACTIVE REGION 12192 FLARE-RICH BUT CME-POOR?},
author = {Sun, Xudong and Bobra, Monica G. and Hoeksema, J. Todd and Liu, Yang and Couvidat, Sebastien and Norton, Aimee A. and Li, Yan and Fisher, George H. and Shen, Chenglong, E-mail: xudong@Sun.stanford.edu},
abstractNote = {Solar active region (AR) 12192 of 2014 October hosts the largest sunspot group in 24 years. It is the most prolific flaring site of Cycle 24 so far, but surprisingly produced no coronal mass ejection (CME) from the core region during its disk passage. Here, we study the magnetic conditions that prevented eruption and the consequences that ensued. We find AR 12192 to be “big but mild”; its core region exhibits weaker non-potentiality, stronger overlying field, and smaller flare-related field changes compared to two other major flare-CME-productive ARs (11429 and 11158). These differences are present in the intensive-type indices (e.g., means) but generally not the extensive ones (e.g., totals). AR 12192's large amount of magnetic free energy does not translate into CME productivity. The unexpected behavior suggests that AR eruptiveness is limited by some relative measure of magnetic non-potentiality over the restriction of background field, and that confined flares may leave weaker photospheric and coronal imprints compared to their eruptive counterparts.},
doi = {10.1088/2041-8205/804/2/L28},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 804,
place = {United States},
year = {2015},
month = {5}
}