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Contraction of flaring loops — the evidence of magnetic reconnection in sheared core fields

Contraction of flaring loops — the evidence of magnetic reconnection in sheared core fields. Haisheng Ji Purple Mountain Observatory Nanjing, 210008, China jihs@pmo.ac.cn. What is the Contraction of flaring loops?.

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Contraction of flaring loops — the evidence of magnetic reconnection in sheared core fields

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  1. Contraction of flaring loops — the evidence of magnetic reconnection in sheared core fields Haisheng Ji Purple Mountain Observatory Nanjing, 210008, China jihs@pmo.ac.cn

  2. What is the Contraction of flaring loops? That is, during the rising phase of solar flares, hard X-ray (HXR) loop-top sources or radio/extreme-ultraviolet (EUV) flaring loops have a descending motion and, at the same time, Hα ribbons or HXR footpoints (FPs) are converging. The usual expansion motion (upward motion + separation motion) of flaring loops occurs only after the contraction.  Unshearing occurs during the contraction as well as the expansion motion.

  3. Dynamic flaring loops — A Summary from our observations

  4. 中国古代天文学家对太阳黑子的描述，大体可分为三大类：中国古代天文学家对太阳黑子的描述，大体可分为三大类： • 第一类，圆形：如钱、如桃、如李、如栗、如环。 • 第二类，椭圆形：如鸡卵、鸭卵、鹅卵、爪、枣。 • 第三类，不规则形：如立人、如踆乌、如飞鹊、如飞燕。

  5. 《淮南子•精神训》载：“日中有踆乌，而月中有蟾蜍。”东汉高诱注云：“踆，犹‘蹲’也，谓三足乌。”晋代学者郭璞（276～324）也有注释说“中有三足乌”。《淮南子•精神训》载：“日中有踆乌，而月中有蟾蜍。”东汉高诱注云：“踆，犹‘蹲’也，谓三足乌。”晋代学者郭璞（276～324）也有注释说“中有三足乌”。

  6. Events showing the contraction • The M1.2 flare of 2002-04-15 (Sui & Holman 2003) • The M2.1 flare of 2002-09-09 (Ji et al. 2004) • The X3.1 flare of 2002-08-24 (Li & Gan 2005) • The X3.9 flare of 2003-11-03 (Veronig et al. 2006) • The M1.2 flare of 2004-11-01 (Ji et al. 2006) • The M6.8 flare of 2003-06-13 (Ji, Huang, & Wang 2007) • The M5.7 flare of 2002-03-14 (Zhou, Ji & Huang 2006) • The X10 flare of 2003-10-29 (Zhou, Ji & Huang 2006; Ji et al. 2008)

  7. The M1.2 flare of 2002-04-15 (Sui and Holman 2003) 10-25 keV • in the early phase of the flares, the looptop sources moves down • Velocity ~ tens of kilometers per second the first SMESE workshop 10-12 March 2008, Paris

  8. The X3.1 flare of 2002-08-24 (Li and Gan 2005) the first SMESE workshop 10-12 March 2008, Paris

  9. The M3.9 flare of 2003-11-03 (Veronig et al. 2006) the first SMESE workshop 10-12 March 2008, Paris

  10. The M2.1 flare of 2002-09-09 (Ji et al. 2004) 17:46UT 25-50 keV 17:41 UT Red: 6-12keV Blue: 12-25kev 25 km/s

  11. The M1.2 flare of 2004-11-01: (Ji et al. 2006) 03:19:08 – 03:19:20 Solid: 25-60 keV Dashed: 6-10 keV 03:18:44 – 03:18:56 the first SMESE workshop 10-12 March 2008, Paris

  12. The M6.8 flare of 2003-06-17 (Ji et al. 2007)

  13. The flare of 2002-03-14 (Zhou et al. 2007) Background: TRACE 171 A Contours: HXR 30-60 keV the first SMESE workshop 10-12 March 2008, Paris

  14. The X10 flare of 2003-10-29 (Ji et al. 2008) • White-light flare (Xu et al. 2004) • Penumbral decay and rapid magnetic changes (Wang et al. 2004) • Gamma-ray (Hurford et al. 2006) • Large scale disturbance (Liu et al. 2006; Balasubramaniam, Pevtsov \& Neidig 2007) • Shear flows (Deng et al. 2006) • Magnetic unshearing after flare (Wang et al. ) • Significant helicity drop after flare (Liu et al. 2007) • Significant geophysical effect (Kwabara et al. 2004) • Contraction-to-expansion (Zhou et al. 2007)

  15. The X10 flare of 2003-10-29 (Ji et al. 2008) 10-25 keV 35-50 keV the first SMESE workshop 10-12 March 2008, Paris

  16. The X10 flare of 2003-10-29 arcade Sigmoid the first SMESE workshop 10-12 March 2008, Paris

  17. The X10 flare of 2003-10-29 (Ji et al. 2008) the first SMESE workshop 10-12 March 2008, Paris

  18. The X10 flare of 2003-10-29 (Ji et al. 2008) Sigmoid phase Arcade phase

  19. The X10 flare of 2003-10-29 (Ji et al. 2008) the first SMESE workshop 10-12 March 2008, Paris

  20. The X10 flare of 2003-10-29 (Ji et al. 2008) Contraction expansion the first SMESE workshop 10-12 March 2008, Paris

  21. The X10 flare of 2003-10-29 (Ji et al. 2008) • Sigmoidal structure first ever seen in HXR • Magnetic reconnection inside the sigmoid • Sigmoid  arcade • Contraction  expansion • Unshearing throughout the flare • Rapid unshearing during the ‘sigmoid’ period the first SMESE workshop 10-12 March 2008, Paris

  22. the first SMESE workshop 10-12 March 2008, Paris

  23. Contraction of flaring loops • ☆ inward motion of conjugate flaring kernels • ☆ shrinkage of flaring loops (radio, EUV) • ☆ descending of HXR looptop sources Expansion of flaring loops • ☆ outward motion of conjugate flare ribbons • ☆ expansion of flare loops (radio, EUV) • ☆ upward motion of HXR looptop sources the first SMESE workshop 10-12 March 2008, Paris

  24. dynamic flare loops B C D A G F E the first SMESE workshop 10-12 March 2008, Paris

  25. dynamic flare loops the first SMESE workshop 10-12 March 2008, Paris

  26. Interpretation of Loop Contraction 10-25 keV • 1. Current sheet formation (Sui & Holman 2003, Sui et al. 2004) • 2. Magnetic shrinkage • (Acton & Forbes1996, Lin 2004) • 3. Collapsing magnetic trap (Veronig et al. 2005) • 4. Magnetic Implosion • (Hudson 2000) reduced the first SMESE workshop 10-12 March 2008, Paris

  27. Our interpretation (Ji et al. 2007) Modifying effect caused by Mapping effect from the Photosphere the first SMESE workshop 10-12 March 2008, Paris

  28. Our interpretation (Ji et al. 2007) • Contraction is the signature of magnetic energy dissipation in highly sheared magnetic field Energy dissipation the first SMESE workshop 10-12 March 2008, Paris

  29. The implication for the relationship of flares and CMEs + sigmoidal phase arcade phase + expansion contraction CMEs the first SMESE workshop 10-12 March 2008, Paris

  30. THANK YOU! the first SMESE workshop 10-12 March 2008, Paris

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