The Flare Build-up Study is a common enterprise of magnetospheric and solar physicists, theorists and observers, that aims at a better understanding of the cosmical acceleration processes that seem to occur in solar flares and in the magnetosphere. It was proposed to the Special Committee on Solar-Terrestrial Physics (SCOSTEP) during its general meeting in London, April, 1973, by the SCOSTEP Steering Committee on Solar and Interplanetary Programs (SIP). During the General Assembly of IAU in Sydney, August, 1973, the IAU Commission 10 on Solar Activity set up a temporary Working Group to study the solar aspects of the FBS, and more specifically, to seek the opinion of solar physicists on this international enterprise. The results of an enquiry among 40 scientists interested in flares have been compiled by Svestka in a report distributed during the Symposium on Solar-Terrestrial Physics in Sao Paulo in June 1974. Parts of this report have been included in the invited lecture presented at the FBS Workshop during that Symposium by De Feiter (1974). On behalf of the FBS Steering Committee, Obayashi, in August, 1974, extended the enquiry to include also magnetospheric physicists, with a response of no less than 114. It seems thus that there is a wide interest in the problems proposed for the study.
Up till now we are in a phase of exploration with the principal aim to define realistic research projects, based upon a critical evaluation of the similarities and differences of the processes in solar flares and in magnetic substorms. Such a critical evaluation can best be carried out during a series of workshop meetings and specialized colloquia, of which the first took place during the Sao Paulo STP Symposium and the second is the one we are about to start.
Apart from the interdisciplinary aspect of the FBS there is a great interest among solar physicists to pursue an investigation of the pure solar aspect, i.e., of the build-up and storage of the flare energy in magnetic field structures. The culmination of this enterprise supposedly will take place during the next solar maximum as one of the projects of the Solar Maximum Year (SMY). Also, the magnetospheric aspects will find much attention during the International Magnetospheric Study (IMS).
So much about the organizational framework. Let us now have a closer look at the scientific contents. Clearly there are two important questions: (1) In what way is, in both cases, the excess energy gradually built up, stored and suddenly released? (2) Are the processes involved in both cases essentially the same, or are they fundamentally different? * Presented by Z. Svestka.