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.

An overview of the relationship between the near space and upper atmospheres. This book discusses basic elements in the auroral process including interplanetary plasma and fields, atmospheres, geomagnetic fields and the ionosphere.

A multitude of processes that operate in the upper atmosphere are revealed by detailed physical and mathematical descriptions of the interactions of particles and radiation, temperatures, spectroscopy and dynamics.

Paperback. The 33 papers published were selected from those given at the above Proceedings, and are divided into three chapters. Chapter 1 provides four papers under the heading Up-dating of CIRA 1986. In Chapter 2, entitled Trace Constituents of the Middle and Upper Atmosphere, the papers published go some way toward providing a set of preliminary reference atmospheres of significant trace species of the middle atmosphere and lower thermosphere. These trace species play important roles in controlling the chemistry, radiation balance and circulation patterns of the Earth's stratosphere, mesosphere and thermosphere. The third chapter, The Localized Response of the Lower Thermosphere and Ionosphere at High Latitudes, describes the broad range of recent advances made by theoretical and modelling activities and also reports on experimental investigations using a wide range of methods, ground-based radar, ground-based optical, space-borne in situ and

Journey to the icy realms of the polar regions with "Polar Exploration" by William Speirs Bruce. Published in the 1910s, this book offers a comprehensive account of various expeditions to the Arctic and Antarctic. Bruce, a renowned explorer himself, provides detailed insights into the challenges, discoveries, and scientific advancements made during these daring voyages. It's a must-read for those fascinated by exploration, history, and the natural world.