The role of enhanced chemical reaction rates in the formation of the daytime F-region trough is examined. A simple convection model is used to estimate the maximum likely elevation of effective temperature for the ion reaction O+ + N2 yields NO(+)+ N. Under extreme conditions the effective temperature can reach 4000 k resulting in a 30-fold increase in the reaction rate. However, the resulting reduction in F-region electron density is only a factor of 4. Under more usual conditions, the reduction is less than a factor of 2. The actual density reduction factor in the daytime trough is observed to vary between 3 and 10 under normal conditions. Therefore, we conclude that under most circumstances, convection-enhanced chemistry contributes very little to the formation of the daytime trough.

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.

This book is an introduction to the use of the ultraviolet for remote sensing of the Earth's atmosphere. It covers the Earth's UV radiative environment, experimental techniques, and current applications. it is my intention to provide the information needed to "make a first approximation" concerning the use of the ultraviolet and to provide access through the literature for a more thorough study.* Contains recent UV applications not previously available in book form such as ozone, auroral images, and ionospheric sensing* Features broad coverage of fundamentals of atmospheric geophysics with values for fluxes, cross-sections, and radiances* Covers techniques that illustrate principles of measurements with typical values* Contains numerous references to original literature