In July 1967 ESRIN and ESLAB, the two ESRO laboratories primarily concerned with basic research, held a joint symposium on Satellite and Rocket Measurements of Corpuscular Radiation from Outer Space. This was followed in September 1968 by a second symposium: Low-Frequency Waves and Irregularities in the Ionosphere; and in September 1969 by a third: Intercorrelated Satellite Observations Related to Solar Events. A fourth symposium, on upper atmospheric models and related experiments, took place in Frascati, 6-10 July 1970. The main aim of the symposium was to ~ssess current experimental work - both field and laboratory - related to mesospheric struc ture and composition, in the light of theoretical work on atmospheric models and atomic and molecular processes. To foster an interdisciplinary approach, the meeting brought together approximately 50 scientists working with different techniques but having a common interest in the interpretation of meso spheric phenomena. Recent work such as that presented at the symposium has deepened our knowledge of upper atmospheric composition, and increased our understanding of upper atmo spheric temperature and dynamics. In particular, it has shown that the concentration of minor species in the atmosphere is somewhat different than expected. Theoretical models have not yet considered many of the minor constituents and have generally not included dynamical effects. It is now time to reconsider these models and elaborate them in the light of recent knowledge.

Inhalt
Aeronomic Reactions of Hydrogen and Ozone.- A Meridional Model of the Oxygen-Hydrogen Atmosphere.- Oxygen, Hydrogen and Nitrogen Constituents in the Mesosphere and Ionization Processes.- Energy Conversions and Mean Vertical Motions in the High Latitude Summer Mesosphere and Lower Thermosphere.- Photochemistry and the Escape Efficiency of Terrestrial Hydrogen.- On the Introduction of Transport Processes into Meso-spheric Models.- Dynamical Modelling of the Stratosphere and Mesosphere.- Tides and Gravity Waves in the Upper Atmosphere.- The Meteorological Structure of the Mesosphere Including Seasonal and Latitudinal Variations.- Nocturnal Variations in the OH (8-3) Band Airglow.- Ultraviolet Solar Radiation Related to Mesospheric Processes.- Penetration of Solar Radiation in the Schumann-Runge Bands of Molecular Oxygen.- Relaxation of the 2.1 #x03BC; and 4.3#x03BC; Bands of Carbon Dioxide.- Laboratory Measurements of D-Region Ion-Molecule Reactions.- The Roles of Water Vapor and Nitric Oxide in Determining Electron Densities in the D-Region.- Discussion of the Formation of Major Positive and Negative Ions up to the 50 km Level.- Electronic Collisions.- Laboratory Studies of Elementary Reactions of Neutral Species Containing O or H.- The Photochemistry of Ozone and Singlet Molecular Oxygen in the Atmosphere.- Laboratory Investigations of the Primary Products of Ozone Photolysis.- The Airglow Reaction at Low Pressures.- On the Origin of Noctilucent Clouds.- The Rate Constants of Some Ion-Molecule and Ion-Electron Reactions, from in Situ Ionospheric Measurements.- On the Semiannual Variation of the Upper Atmosphere.- Rocket Measurements of Ion and Electron Densities in the D-Region during Sunrise.- Ion Densities in the Lower D-Region Measured with a Parachuted Probe.- IonComposition in the E and Lower F-Region above Kiruna at Sunset and Sunrise.- Rocket Mass Spectrometry in Japan.- Measurement of Submillimeter-Wave Stratospheric Emission Spectra.- Some Effects of Dimers of the Water Molecule in the Atmosphere.