Symposium On The Structure And Development Of Solar Active Regions

K. O. KIEPENHEUER ( Fraunhofer Institut, Freiburg i. Br., Germany) The present symposium, to my knowledge the largest ever held in the field of solar research (170 astronomers from 21 countries) was held in the building of the Hun garian Academy of Sciences in Budapest from September 4 to 8, 1967. It was the 35th symposium organized and sponsored by the International Astronomical Union. The majority of participants were financedfrom national sources. The Organizing Commit tee consisted of K. O. Kiepenheuer (Chairman), L. Davis, L. Dezso (Local Organizer), A.D. Fokker, R. Michard, A.B. Severny, H.J. Smith, Z. Svestka, and H. Tanaka. In order to ensure prompt publication, the manuscripts had to be supplied by the authors 1 month after the meeting. The discussions have been recorded on tape. Their reproduction in this book, however, is based almost completely on the contributors' writing down their comments and questions on the spot. Two special projects have been reported and discussed shortly during the sym posium: The world wide project 'Cooperative Study of Solar Active Regions' (CSSAR) organized by Dr. R. Michard, under the auspices of the IAU, which has put at the disposal of our solar community a precious observing material on Active Regions over a period of 6 months.

This volume contains the review papers presented at the International Symposium on Solar-Terrestrial Physics held at the Tavrichesky Palace, Leningrad, U.S.S.R., 11-19 May 1970. The Symposium may be regarded as the most recent member of a series of inter national symposia - for instance, the Symposium on Solar-Terrestrial Physics, Belgrade (1966), the Joint IQSY-COSPAR Symposium on Solar-Terrestrial Physics, London (1967), and the Symposium on the Physics of the Magnetosphere, Washington (1968). Like those earlier symposia, the Leningrad Symposium was sponsored by the International Astronomical Union (IAU), the International Union of Geodesy and Geophysics (IUGG), the International Union of Radio Sciences (URSI), and the ICSU Committee on Space Research (COSPAR). These bodies are all concerned with one or another aspect of solar-terrestrial physics, and all joined in believing that the time was ripe for another comprehensive symposium on all aspects of this very active field of research.

Topics include magnetic structure of interplanetary and solar magnetic fields and solar wind.