We observed a Moreton wave associated with a flare of importance 3B in the NOAA region 6659 on 1991 June 4. The Moreton wave was emitted from a flare bright point and initially showed the form of a loop. The speed of the Moreton wave was initially 1500 km s-1 and was later accelerated to 1800 km s-1. This acceleration may be due to the propagation of the wave into a coronal hole (with low density and high Alfvén velocity.
Report of the National Astronomical Observatory of Japan
- Pub Date:
- September 2003
- Solar Flares;
- Solar Coronal Holes