Discussion paper: Comments on physical properties of...

2. Several Comments on Events of November 2004

[5] A very bright and broad loop front development was documented by the SOHO/LASCO C2 coronograph around N09W17, with weak propagation to south. Full Halo was formed at 1706 UT. The first appearance of the ejecta in the field of view of the LASCO/C3 coronograph occurred 1718 UT. The average propagation velocity of the perturbation in the picture plane was 1460 km s^-1. The initial interpretation by several observers suggested an association exclusively with the dynamical processes in only one the Active Region AR 10696 in the northern hemisphere [Panasyuk et al., 2004; Yermolaev et al., 2005]. Such localization appeared to be not quite correct and to be partially misleading because of obvious dynamical connections with other active regions (ARs) 10695 and 10693 in the southern hemisphere. In reality, a transequatorial prominence was seen here in between active regions. It was partially erupted.

Figure 1

[6] This observation provides the key and a clear indication that strongest events in the heliosphere have a relation to the evolution of the larger-scale structures and processes on the Sun, transequatorial ones among them, and not only just one active region as usually assumed a priori without sufficient justifications. Moreover, according to our hypothesis, namely, that these larger scales are providers of the needed free energy for eruptive phenomena with their manifestations as flares and CMEs [Panasyuk et al., 2004; Zhukov et al., 2004(available at http://www.congrex.nl/04c27/4)]. In the November 2004 case, multiple CMEs originated around the central meridian and in the southwest part of the disk. Corresponding electric and magnetic fields with electric currents were responsible for this evolution. Several large dimmings were seen in Extreme ultraviolet Imaging Telescope (EIT) images here on 7 November around ARs 10696, 10695 and 10693. It is not just a projection effect but is also an indication of the tight couplings in their evolution (Figure 1).

Figure 2

Figure 3

[7] Other evidence of the large-scale changes showing the disappearance of the part of the very long transequatorial filament (prominence) can be seen in Figure 2. Sequential pictures were taken in the H -alpha line at the Kanzelhöhe Solar Observatory.

[8] The magnetic field in the corona was calculated by G. V. Rudenko (http://bdm.iszf.irk.ru) in different approximations using photospheric magnetograms for this period of time. Results also clearly show large-scale loops connecting different active regions (Figure 3). Long-distance nonlocal couplings are possible via electric currents and heat fluxes along these loops.