1yang liu1997 may 12 event the 1997 may 12 event yang liu – stanford university...
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2Yang Liu1997 May 12 Event
The 1997 May 12 Event
• Observations for this event.
• Vector magnetic field data reduction.
• Variation of magnetic field during this event.
• Extrapolation of the coronal magnetic field.
• Disturbance at the north pole.
• Modeling for the presumed flux rope.
3Yang Liu1997 May 12 Event
Observations of this event—solar surface
Ha MDI
4Yang Liu1997 May 12 Event
Observations of this event—solar surface
Observation shows a classic two-ribbon flare.
SXT EIT
Ha MDI
5Yang Liu1997 May 12 Event
Observations of this event—corona/heliosphere
Full Halo CME
LDE Slow CME
6Yang Liu1997 May 12 Event
Observations of this event—corona/heliosphere
MC
Bs
Full Halo CME
LDE Slow CME
7Yang Liu1997 May 12 Event
Observations of this event--summary
• A typical two-ribbon flare;
• Long decay phase;
• A filament’s eruption;
• EUV double dimming;
• EIT wave;
• A slow full-halo CME;
• A magnetic cloud;
• A geomagnetic storm.
8Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
9Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
10Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
11Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
12Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
13Yang Liu1997 May 12 Event
Vector magnetic field data—before the event.
• Vector data before the flare (Mitaka)
14Yang Liu1997 May 12 Event
Vector magnetic field data—after the event.
• Vector data after the flare (19:23UT @ Mees)
15Yang Liu1997 May 12 Event
Variation of magnetic field during the event—on small scale
Vector magnetic field
16Yang Liu1997 May 12 Event
Variation of magnetic field during the event—on small scale
Vector magnetic field
Histograms for magnetic shear angle
17Yang Liu1997 May 12 Event
Variation of magnetic field during the event—on small scale
Magnetic fields appear changes on small scale after the flare.
Vector magnetic field Vertical electric current, over-plotted by the line-of-sight magnetograms
Histograms for magnetic shear angle
18Yang Liu1997 May 12 Event
Variation of magnetic field during the event—on large scale
Magnetic field appears changes in large-scale fields after the flare.
PFSS model for coronal field
Average height of field lines above AR8038
Change of magnetic field
19Yang Liu1997 May 12 Event
Evolution of magnetic field of AR8038.
20Yang Liu1997 May 12 Event
Evolution of magnetic field of AR8038.
21Yang Liu1997 May 12 Event
Evolution of magnetic field of AR8038.
22Yang Liu1997 May 12 Event
Evolution of magnetic field of AR8038.
23Yang Liu1997 May 12 Event
Extrapolation of coronal magnetic field.
24Yang Liu1997 May 12 Event
Disturbance at the north pole
25Yang Liu1997 May 12 Event
Modeling the presumed flux rope
Model r distance flux electric twist
10^9cm 10^9cm 10^20Mx 10^11A π
obs 2.8 9.6 1.01 2.69 0.80
TD model 2.8 9.6 1.01 3.17 0.94
TD model: Titov and Demoulin (1999) propose a flux rope model. The ring current along the rope can be estimated from available observation.
26Yang Liu1997 May 12 Event
Modeling the presumed flux rope
Model r distance flux electric twist
10^9cm 10^9cm 10^20Mx 10^11A π
obs 2.8 9.6 1.01 2.69 0.80
TD model 2.8 9.6 1.01 3.17 0.94
Tested by LFFF
TD model: Titov and Demoulin (1999) propose a flux rope model. The ring current along the rope can be estimated from available observation.
27Yang Liu1997 May 12 Event
Modeling the presumed flux rope
Model r distance flux electric twist
10^9cm 10^9cm 10^20Mx 10^11A π
obs 2.8 9.6 1.01 2.69 0.80
TD model 2.8 9.6 1.01 3.17 0.94
Tested by LFFF
The twists from these two methods are in reasonable agreement, but both are much less than the one for eruptive prominences (Vrsnak, et al, 1991), and also less than the theoretical one for a kink instability, implying that the twist alone might be insufficient to lead to this eruption.
TD model: Titov and Demoulin (1999) propose a flux rope model. The ring current along the rope can be estimated from available observation.