This book is an ordered collection of tutorial lectures on the physical processes in the polar upper atmosphere given at the NATO Advanced Study Institute (ASI) on "The Exploration of the Polar Upper Atmosphere" held at Lillehammer, Norway, May 5-16, 1980. The polar cap is an important part of the high latitude atmosphere not only because of circulation and horizontal trans­ port in the neutral atmosphere and convection in the ionosphere, but also because of its unique energy sources and sinks. In addition, solar wind plasma is led into-the upper atmosphere by the geomagnetic field at the poles, and the polar cap is, as stated by Tutorial Leader Roederer in this volume, "the place where outer space meets earth". The atmosphere at lower latitudes is well-known to the ground-based observer, and the advent of satellite observations was simply the beginning of a new perspective. The exploration of the atmosphere at polar latitudes, however, proceeded in quite the opposite manner, and satellite maps of the polar caps may be compared with a relatively meagre set of ground-based data. Recent efforts to extend the polar observations from the ground have resulted in the need for a review of the physical principles and processes occurring in the polar upper atmosphere. The interdisciplinary nature of these efforts led to the emphasis here on a tutorial program.

Inhalt

I: The Neutral Polar Atmosphere Above the Tropopause Tutorial Leader: H E Volland.- Middle Atmosphere Dynamics and Composition.- Dynamics of the Thermosphere during Quiet and Disturbed Conditions.- Wind Induced Composition Effects at High Latitudes.- II: The Polar Ionosphere Tutorial Leaders: P Stubbe (F-Region) L Thomas (D- and F-Region).- The Polar F-Region - Theory.- Radio Observations of the Auroral F-Region.- Modification of the F-Region by Powerful Radio Waves.- The Lower Ionosphere at High Latitudes.- Energy Sources of the High Latitude Upper Atmosphere.- Techniques for Observing D-Region Ionization.- Auroral Radio Absorption in Relation to Magnetospheric Particles.- III: Optical Remote Sensing of the Polar Atmosphere and Ionosphere Tutorial Leader: G G Shepherd.- Optical Remote Sensing of the Polar Upper Atmosphere.- Polar Cap Optical Emissions Observed from the ISIS2 Satellite.- Optical Emissions in the Polar Auroral E-Region.- A review of Optical F-Region Processes in the Polar Atmosphere.- Neutral Winds in the Polar Cap.- Difference in Polar Atmospheric Optical Emissions between Mid-Day and Night-Time Auroras.- IV: Solar-Magnetosphere-Polar Atmosphere Interactions Tutorial Leader: J G Roederer.- The Solar Wind-Magnetosphere-Ionosphere System: An Overview.- The Distant Magnetosphere: Reconnection in the Boundary Layers, Cusps and Tail Lobes.- Plasma Sheet Dynamics: Effects on, and Feedback from, the Polar Ionosphere.- Relationships between the Solar Wind and the Polar Cap Magnetic Activity.- Auroral Morphology: A Television Image of Solar and Magnetospheric Activity.- V: Electric Fields and Currents at High Latitudes Tutorial Leader: T. Stockflet J0rgensen.- Electric Fields in the Dayside Auroral Region.- Electric Fields and Electrostatic Potentials in the High Latitude Ionosphere.- Spatial Variations of Ionospheric Electric Fields at High Latitudes on Magnetic Quiet Days.- Electric Field Measurements with Balloons.- High Latitude Ionospheric Currents.- ISIS Observations of Auroral Particles and Large-Scale Birkeland Currents.- VI: Waves and Particles in the Polar Regions Tutorial Leader: R Gendrin.- Some Aspects of ULF Waves Observed Onboard GEOS Related to Convection, Heating and Precipitation Processes.- Electron Cyclotron Waves in the Earth's Magnetosphere.- Magnetospheric Hot Plasma Measurements in Relation to Wave-Particle Interactions on High-Latitude Magnetic Field Lines.- Mechanisms for Intense Relativistic Electron Precipitation.- Electrostatic Waves in the Ionosphere.- VII: Historical Exploration of the Polar Upper Atmosphere Tutorial Leader: A Brekke.- The Changing Aurora of the Past Three Centuries.- Aurorae, Sunspots and Weather, Mainly Since A.D. 1200.- Ancient Norwegian Literature in Relation to the Auroral Oval.- On the Literature of the Aurora in Nordic Countries.- VIII: Applications of Polar Upper Atmosphere Research Tutorial Leader: E V Thrane.- Effects of Ionospheric Disturbances on High Latitude Radio Wave Propagation.- The Variability and Predictability of the Main Ionospheric Trough.- A Report from the International Solar-Terrestrial Prediction Workshop. Boulder 23-27 April 1979..- E and F Region Predictions for Communication Purposes at High Latitudes.