Arctic Ionosphere And Aurora

In response to Air Force needs for specifying and forecasting conditions of the Arctic ionosphere, AFCRL's Airborne Ionospheric Laboratory, a highly instrumented NKC 135 jet aircraft, was used in an extensive Arctic research program that started in 1967. To date, 69 flights were made and ionospheric and optical data covering major parts of the auroral oval, mainly the midday sector and the night sector, were collected. During the winter months of 1967, 1968, 1969, and 1970 special emphasis was put on the investigation of the day sector. These flights covered a rather unique and poorly investigated area of the auroral oval, and a detailed report on the observations is given here. A thorough analysis of the data collected in the day sector reveals the existence of a band of continuous particle precipitation south of the location of the discrete aurora. This precipitation hardens towards the south and results in E- and D-region ionization. These observations compare very well with measurements of precipitating particles done by satellite. The investigation of the evening and night sectors showed similar but less organized trends than on the day side. During several flights the continuity of the auroral oval was verified. The investigation indicates that, with additional measurements, it may be possible to develop a model of the Arctic ionosphere. With control measurements from a few ideally located ground stations, the dynamics of the Arctic ionosphere might then be utilized for forecasting propagation conditions in the Arctic. (Author).

The auroral emissions in the upper atmosphere of the polar regions of the Earth are evidence of the capture of energetic particles from the Sun, streaming by the Earth as the solar wind. These auroral emissions, then, are a window to outer space, and can provide us with valuable information about electrodynamic coupling processes between the solar wind and the Earth's ionosphere and upper atmosphere. Studying the physics of these phenomena extends our understanding of our plasma universe. Ground-based remote-sensing techniques, able to monitor continuously the variations in the signatures of aurorae, in combination with in-situ satellite and rocket measurements, promise to advance dramatically our understanding of the physical processes taking place at the interface of the atmospheres of the Earth and the Sun. Decoding their complexity brings us closer to reliable prediction of communication environments, especially at high latitudes. This understanding, in turn, will help us resolve problems of communication and navigation across polar regions.

Popular natural history writer Savage takes readers inside the mystery of the beautiful phenomenon of the aurora borealis, explaining how aurorae happen and how humans have stood in awe and devised whole cosmologies around them since time immemorial. Over 60 photos, 34 in color. Map.

During long winter nights, the light of the aurora borealis appears over the sparcely populated north. Little is known, however, about these dazzling displays of ghostly light and movement. The author discusses the history, mythology, and science behind auroras. Demonstrating the influence of the sun in the aurora's creation, he also compares the northern lights with phenomena such as lightning and rainbows. Lavishly illustrated with numerous color and black and white pictures, Aurora offers a comprehensive understanding of a mysterious dynamic that has fascinated and even alarmed northern communities through the ages.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 197. Many of the most basic aspects of the aurora remain unexplained. While in the past terrestrial and planetary auroras have been largely treated in separate books, Auroral Phenomenology and Magnetospheric Processes: Earth and Other Planets takes a holistic approach, treating the aurora as a fundamental process and discussing the phenomenology, physics, and relationship with the respective planetary magnetospheres in one volume. While there are some behaviors common in auroras of the different planets, there are also striking differences that test our basic understanding of auroral processes. The objective, upon which this monograph is focused, is to connect our knowledge of auroral morphology to the physical processes in the magnetosphere that power and structure discrete and diffuse auroras. Understanding this connection will result in a more complete explanation of the aurora and also further the goal of being able to interpret the global auroral distributions as a dynamic map of the magnetosphere. The volume synthesizes five major areas: auroral phenomenology, aurora and ionospheric electrodynamics, discrete auroral acceleration, aurora and magnetospheric dynamics, and comparative planetary aurora. Covering the recent advances in observations, simulation, and theory, this book will serve a broad community of scientists, including graduate students, studying auroras at Mars, Earth, Saturn, and Jupiter. Projected beyond our solar system, it may also be of interest for astronomers who are looking for aurora-active exoplanets.