Soft X-Ray and White-Light Coronal Observations of the Post-Flare Arch on 2 November 1991

A giant post-flare arch observed on 2-3 November 1991 was analyzed using the soft X-ray telescope (SXT) on board Yohkoh and the Mark III (MK3) K-coronameter at the High Altitude Observatory/Mauna Loa Solar Observatory. The rising arch was observed in both soft X-ray and K-corona observations. The estimated rising speed from the MK3 observation was approximately 4 km s-1. A V-shaped depression area was observed on the south side of the giant arch. Change in the K-corona observations was faint while the arch was rising. According to the solar wind observations by the Pioneer Venus Orbiter and the Interplanetary Cometary Explorer, this giant arch event may have been associated with an interplanetary shock.