On the Chromospheric Evaporation
Observed during the X1.4 Flare of 12-July, 2012

Aki Takeda, Keiji Yoshimura, and David E. McKenzie (Montana State University)

1. Introduction

Solar activity



XRT synoptic(whole sun) observation movie (7-jul to 15-jul).

AR11520



XRT movie for the X-flare(12-jul 13:30 --- 23:43UT).

SDO/AIA movies:
1600304 171193 211335 13194

NSO/GONG: H-alpha movie.
RHESSI: RHESSI images (12-Jul-2012)    and    RHESSI(3-6keV) & XRT (the same day).

(1) Drastic sunspot motions

SDO/HMI Differential rotation corrected movie (7/07 00:00 --- 7/16 00:00)

(2) Interaction among Sigmoid loops --- flare triger?

About one hour prior to the flare onset, interaction among the sigmoid loops were observed.

(3) Expansion and escape of sigmoid loops --- flare enhancement?

(4) Soft X-ray flare ribbon?

Te-EM analysis from the XRT images.
Filter Ratio Te & EM movie (7/12 16:20 -- 16:38)     Te: in log (K), EM: in log (cm^-3).
    XRT filter ratio function (thick-Be/thick-Al)

Derived temperature and emission measure of the ribbon.
Te ~ 2MK (logT ~6.3)
EM ~ 10^45 cm^(-3) ---> Ne ~ 10^10 cm^(-3) assuming 3000km line-of-sight depth.

(5) Wings from the sigmoid ends?

Base difference movie of AIA 304 images (left) and overlay of extracted wing structures on HMI magnetogram (right).

   

[Detailed study of the East wing] 

--- Approx. by 2 circular arcs. and make a stack plot ---
[Arc-1] radius : 150 (pix), angle range :  90 to 145 (deg)
[Arc-2] radius : 150 (pix), angle range : 170 to 270 (deg)

sampling scale of the arcs : 1 (pix/deg)
slope of the fastest part of the stack plot : 87(=133-46) pix in hrizontal scale of the stack plot.
      ---> 87 deg.       ;  on 150 pix radius arc.
      ---> 228 pix       ;  2*!pi*150*(87/360) on the AIA image scale.
      ---> 137 arcsec    ;  288 * 0.60 (arcsec/pix, AIA pix-res)
      ---> 100958 km     ;  137 /3600*!dtor * aia_index.dsun_obs * 0.001 

    (111-132) pix in vertical direction  
      ---> time difference of the No.111 (16:36:44) and No.132 (16:49:22) images
      ---> 758 sec.

speed of expansion : 133 (km/s)




Timeline of the AR evolution

  1. 2012/07/06 04:00:00 --- East limb passage.
  2. 2012/07/08 00:00:00 --- Emergence of N4-P4 pairs.
  3. 2012/07/09 23:03:00 --- M1.1 flare between N4-P4.
  4. 2012/07/10 04:58:00 --- M1.7 flare between N4-P4.
  5. 2012/07/10 06:05:00 --- M2.0 flare among N4-P4, P2.
  6. 2012/07/10 12:08:00 --- C5.5 flare among N4-P4, P2.
  7. 2012/07/10 12:37:00 --- C4.6 flare among N4-P4, P2.
  8. 2012/07/10 15:27:00 --- C5.6 flare between N4-P1.
  9. 2012/07/11 00:00:00 --- Lower loops started to extend to SW.
  10. 2012/07/11 21:44:00 --- C5.6 flare among N4-P2, P4.
  11. 2012/07/12 01:23:00 --- C4.0 flare between N4-P1.
  12. 2012/07/12 07:46:00 --- C3.1 flare between N4-P1.
  13. 2012/07/12 12:40:00 --- Sigmoid loops brightening in 94A.
  14. 2012/07/12 13:30:00 --- Bar loop started to appear in 131A.
  15. 2012/07/12 14:13:00 --- Bar loop & sigmoid loop interaction.
  16. 2012/07/12 14:50:00 --- Sigmoid loop W-end small erruptiion in 94A.
  17. 2012/07/12 15:00:00 --- Sigmoid loop started activated.
  18. 2012/07/12 15:05:00 --- Lower loops started to expand to SW.
  19. 2012/07/12 15:37:00 --- X1.4 flare started (GOES criterion).
  20. 2012/07/12 15:39:00 --- Brightening around P2 light-bridge in 1600A.
  21. 2012/07/12 15:45:00 --- Main flare ribbon started to appear in 1600A.
  22. 2012/07/12 15:50:00 --- Sigmoid loop W-end little shrinkage in 94A.
  23. 2012/07/12 15:55:00 --- Sigmoid loop started fast to expand in 94A.
  24. 2012/07/12 15:59:00 --- West bat wing started to extend in 1600A.
  25. 2012/07/12 16:26:00 --- Flare ribbon extension in XRT.
  26. 2012/07/12 16:27:00 --- West-side post flare loops developed.
  27. 2012/07/12 16:39:00 --- East bat wing started to extend in 1600A.
  28. 2012/07/12 16:40:00 --- East-side post flare loops developed.
  29. 2012/07/14 04:51:00 --- M1.0 flare between N4-P1.