PAGEOPH, stratosphere, these differences provide us with new evidence, interpretation of which can materially help to advance our understanding of stratospheric dynamics in general. It is now weil established that smaller-scale motions-in particular gravity waves and turbulence-are of fundamental importance in the general circulation of the mesosphere; they seem to be similarly, if less spectacularly, significant in the troposphere, and probably also in the stratosphere. Our understanding of these motions, their effects on the mean circulation and their mutual interactions is progressing rapidly, as is weil illustrated by the papers in this issue; there are reports of observational studies, especially with new instruments such as the Japanese MV radar, reviews of the state of theory, a laboratory study and an analysis of gravity waves and their effects in the high resolution "SKYHI" general circulation model. There are good reasons to suspect that gravity waves may be of crucial significance in making the stratospheric circulation the way it is (modeling experience being one suggestive piece of evidence for this). Direct observational proof has thus far been prevented by the difficulty of making observations of such scales of motion in this region; in one study reported here, falling sphere observations are used to obtain information on the structure and intensity of waves in the upper stratosphere.

Humanity has long been fascinated by the planet Mars. Was its climate ever conducive to life? What is the atmosphere like today and why did it change so dramatically over time? Eleven spacecraft have successfully flown to Mars since the Viking mission of the 1970s and early 1980s. These orbiters, landers and rovers have generated vast amounts of data that now span a Martian decade (roughly eighteen years). This new volume brings together the many new ideas about the atmosphere and climate system that have emerged, including the complex interplay of the volatile and dust cycles, the atmosphere-surface interactions that connect them over time, and the diversity of the planet's environment and its complex history. Including tutorials and explanations of complicated ideas, students, researchers and non-specialists alike are able to use this resource to gain a thorough and up-to-date understanding of this most Earth-like of planetary neighbours.

Especially due to the increasing environmental problems there is a need to collect as many data as possible in the upper atmosphere. This book serves as a general multidisciplinary guide and introduction for a more effective use of the large amount of now available data from the Earth's atmosphere. It also shows the problems of the use of large amounts of time series data - for basic science as well as for environmental monitoring - and the related information systems. The book is aimed for scientists and students interested in the Earth's atmosphere which is vital for the understanding of environmental changes in the global system Earth.

The Earth’s Middle Atmosphere covers the Proceedings of Symposium C2 and the Topical Meetings of the COSPAR Interdisciplinary Scientific Commissions A and C (Meetings A7 and C4) of the COSPAR 29th Plenary Meeting held in Washington, DC, USA, on August 28-September 5, 1992. The first part covers the impact of the Upper Atmosphere Research Satellite (UARS) observations on middle atmosphere science. This topic includes the early results of the validation and the application of the Cryogenic Limb Array Etalon Spectrometer (CLAES) data, which is an instrumental approach to the measurement of thermal infrared spectral emission from the atmospheric limb. An overview of the Halogen Occultation Experiment and the use of the UARS data in the NOAA stratospheric monitoring are also discussed in this part. It also includes the observed solar UV irradiance variations of importance to middle atmosphere energetic and photochemistry, as well as the stratospheric and mesospheric observations with the Improved Stratospheric and Mesospheric Sounder. The second part of the book tackles the energetics and chemistry of the middle atmosphere as well as the dynamics and coupling of the middle atmosphere to regions above and below. Results on the validation of the UARS wind and temperature measurements at and above the mesopause comprise the third part of this book. This book will be a great value to geophysicists and atmospheric scientists.

Paperback. The section entitled Horizontal and Vertical Small Scale Structures in the Middle Atmosphere contains fifteen papers which deal with the dynamics or the effects of dynamics in the Earth's middle atmosphere. Data is presented for all altitude layers between the troposphere and the lower thermosphere using ground-based, balloon-borne, rocket-borne and satellite experiments. Initial results from the CRISTA instrument of the Space Shuttle mission STS-66 are included which measured trace gas emissions from the middle atmosphere with very high spatial resolution in all three dimensions in order to derive dynamics parameters. Small and medium scale dynamics are included in models of the middle atmosphere which are presented in the theoretical papers.The second section, Advances in Optical Remote Sensing of the Upper Atmosphere, reviews recent advances in optical techniques for remote sensing of the upper atmosphere: twelve papers