In the northern coronal hole we may have observed a bi-directional jet with an observed velocity range of between 150 km s-1 in the blue wing and 150 km s-1 in the red wing. The life time for this event is approximately 160 s with a length approximately 35 arc sec. This extension implies that the jet reaches the corona and travels down along most of the transition region. As has been shown by previous observations, the incidence of these explosive events seems to be limited to transition region lines.
In the events observed in the active region the observed velocities range between 250 km s-1 in the blue wing to 215 km s-1 in the red wing. The life time for these events ranges between 60 to 90 s. As with other authors before us, we have associated the active region explosive events to regions with weak and bipolar magnetic fields. A more detailed comparison of these observations with an ongoing explosive event modelling programme is underway (Erdélyi et al. 1999).
© European Southern Observatory (ESO) 1999
Online publication: December 22, 1998