RESPONSE OF THE PHOTOSPHERIC MAGNETIC FIELD TO THE X2.2 FLARE ON 2011 FEBRUARY 15
RESPONSE OF THE PHOTOSPHERIC MAGNETIC FIELD TO THE X2.2 FLARE ON 2011 FEBRUARY 15
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DOI：
10.1088/2041-8205/745/2/l17
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发表时间：
2011-12
期刊：
影响因子：
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通讯作者：
Shuo Wang;Chang Liu;Rui Liu;N. Deng;Yang Liu;Haimin Wang
中科院分区：
文献类型：
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作者：
Shuo Wang;Chang Liu;Rui Liu;N. Deng;Yang Liu;Haimin Wang
众所周知，光球磁场的长期演变在为太阳爆发提供自由能量方面起着重要作用。观测结果尽管存在争议，但也揭示了在火山爆发期间，由于日冕磁场的重构，光球磁场发生了快速而持久的变化。新发射的太阳动力学观测站上的日震和磁成像仪（HMI）以一贯的高分辨率和高节奏产生无视觉的全盘矢量磁图，最终使对这一重要的反反应过程进行明确和全面的研究成为可能。在这项研究中，我们展示了2011年2月15日在NOAA AR 11158中发生的一个接近圆盘中心的goes级X2.2耀斑。利用HMI进行的磁场测量，我们获得了第一个确凿的证据，证明在耀斑磁极性反转线（PIL）的水平磁场快速（约30分钟）和不可逆的增强，幅度约为30%。结果表明，光球场的剪切性和倾斜度增大。这一场演化与耀斑在这一s型活跃区的发生有明确的联系，增强区位于两个色球耀斑带和初始共轭硬x射线脚点之间。这些结果有力地证实了我们之前的猜想，即火山爆发后，PIL附近的光球磁场一定变得更加水平，这可能与割绳重连导致新形成的低洼磁场有关。
It is well known that the long-term evolution of the photospheric magnetic field plays an important role in building up free energy to power solar eruptions. Observations, despite being controversial, have also revealed a rapid and permanent variation of the photospheric magnetic field in response to the coronal magnetic field restructuring during the eruption. The Helioseismic and Magnetic Imager instrument (HMI) on board the newly launched Solar Dynamics Observatory produces seeing-free full-disk vector magnetograms at consistently high resolution and high cadence, which finally makes possible an unambiguous and comprehensive study of this important back-reaction process. In this study, we present a near disk-center, GOES-class X2.2 flare, which occurred in NOAA AR 11158 on 2011 February 15. Using the magnetic field measurements made by HMI, we obtained the first solid evidence of a rapid (in about 30 minutes) and irreversible enhancement in the horizontal magnetic field at the flaring magnetic polarity inversion line (PIL) by a magnitude of ∼30%. It is also shown that the photospheric field becomes more sheared and more inclined. This field evolution is unequivocally associated with the flare occurrence in this sigmoidal active region, with the enhancement area located in between the two chromospheric flare ribbons and the initial conjugate hard X-ray footpoints. These results strongly corroborate our previous conjecture that the photospheric magnetic field near the PIL must become more horizontal after eruptions, which could be related to the newly formed low-lying fields resulting from the tether-cutting reconnection.