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.
