Figure 1
Figure 2
(1). A complete halo CME with speed 250 +/- 20 Km*s^-1; (2). Associated with a C1.3 flare (Figure 1 )at 0442UT on 12 May 1997 in active region NOAA8038 (N21W08) that is the only active region in solar disk (Figure 2); (3) EIT wave (Figure 3); and (4) eruption of filament (Figure 4) (see Webb, et al, 2000, JGR, 105, 27251).
On the other hands, Zhao et al (2002) determined the kinematic property for the 1997 May 12 event using the "cone model". The halo CME was radially accelerated from 200 km/s at about 9.5 solar radii to 650 km/s at about 24 solar radii. The front acceleration is about 18.5 m/s^2. The speed in the plane of the sky ranges from 237 km/s to 307 km/s for the asynptopic radial speed of 650 km/s.
There are a few estimete for the SKY-PLANE speed of the 12 may 1997 event (constant 250 km/s from Plunkett et al., 1998; decelerated from 335 to 220 km/s from http://cdaw.gsfc.nasa.gov/CME_list/UNIVERSAL/1997_05/univ1997_05.html; accelration from Sheeley et al., 1999). Our result is consistent with Sheeley's (see Summary of the paper for details).
Vector field observation of AR8038 was taken at Mitaka, Japan (23:00UT--07:00UT), from May 9 to May 12 with cadence of several minutes, and at Huairou, China, on May 13 with cadence of several ten minutes.
Figure 5a
Figure 5b
Figure 5c
Figure 5d
Non-linear force free field is computed from observed vector magnetic field at the photosphere. Figure 5a-d are force lines in AR8038 on May 10, 11, 12, and 13, respectively.
The distribution of vertical current is calculated and overploted onto the magnetograms. Figure 6 shows evolution of vertical current from May 10 to May 13; Figure 7 is the current before and after the C1.3 flare on May 12. Figure 8 is the variation of total current in the active region AR8038. Note time is Japan Standard Time.
