Open regions have field lines going out into space. Open regions are called coronal holes, because they appear dimmer than the surrounding corona. In a few sessions, things that had puzzled everybody for decades just fell into place. Art received two NCAR Outstanding Publication Awards recognizing his efforts in the 1970s. Art became principal scientist on SMM, contributing analysis and theory that pointed to the magnetically closed regions in the corona as the probable source of these interplanetary shock waves.
Some researchers still subscribe to the theory that solar flares are the cause of CMEs.
But many more, including Art, believe the flares are the aftereffect of much larger mass ejections of solar plasma. The flares are the aftereffect of the mass ejection. The bottom line, says Art, is that the cause of CMEs is still a mystery. We're at the point now where I think we know pretty much what the observations presently available can tell us. We need a whole new generation of observations to make the next step.