OPENING ADDRESS XI LIST OF PARTICIPANTS XV SESSION 1 THE ATMOSPHERE AND IONOSPHERE BELOW 150 km L. Thomas SOME OUTSTANDING PROBLEMS IN THE NEUTRAL AND IONIZED ATMOSPHERE BETWEEN 60 AND 150 km ALTITUDE 3 Peter M. Banks HIGH-LATITUDE IONOSPHERE-ATMOSPHERE INTERACTIONS (Abstract) 19 V. Domingo SOLAR RADIATION VARIATION AND CLIMATE 21 R. Bernard MAREES ET ONDES PLANETAIRES DANS LA BASSE THERMOSPHERE ET LA HAUTE MESOSPHERE 43 Michel Blanc and Paul Amayenc CONTRIBUTION OF INCOHERENT SCATTER RADARS TO THE STUDY OF MIDDLE AND LOW LATITUDE IONOSPHERIC ELECTRIC FIELDS 61 SESSION 2 THE OZONOSPHERE T. M....