active corona
5.Conclusions obtained are (l) that majoradvances in this kind of prediction had been made in the 1960s and 1970s, (2) that theproblems the forecasters are now facing are search for new prediction methods and thepropagation process of proton beams in the solar corona and interplanetary medium, and(3) that a new classification of solar active regions from the point of view of space weatherprediction seems to be very much needed.

