Major surge activity of super-active region NOAA 10484

Abstract

We observed two surges in Hα from the super-active region NOAA 10484. The first surge was associated with an SF/C4.3 class flare. The second one was a major surge associated with a SF/C3.9 flare. This surge was also observedwith SOHO/EIT in 195 Å and NoRH in 17 GHz, and showed similar evolution in these wavelengths. The major surge had an ejective funnel-shaped spray structure with fast expansion in linear (about 1.2 x10⁵ km) and angular (about 65º) size during its maximum phase. The mass motion of the surge was along open magnetic field lines, with average velocity about 100km s-1. The de-twisting motion of the surge reveals relaxation of sheared and twisted magnetic flux. The SOHO/MDI magnetograms reveal that the surges occurred at the site of companion sunspots where positive flux emerged, converged, and canceled against surrounding field of opposite polarity. Our observations support magnetic reconnection models for the surges and jets.