Ionospheres provides a comprehensive description of the physical, plasma and chemical processes controlling the behavior of ionospheres. The relevant transport equations and related coefficients are derived in detail and their applicability and limitations are described. Relevant wave processes are outlined and important ion chemical processes and reaction rates are presented. The various energy deposition and transfer mechanisms are described in some detail, and a chapter is devoted to the various processes controlling the upper atmosphere and exosphere. The second half of the book presents our current understanding of the structure, chemistry, dynamics and energetics of the terrestrial ionosphere, and other solar system bodies. The final chapter describes ionospheric measurement techniques. The book will form a comprehensive and lasting reference for scientists interested in ionospheres, and it will also prove an ideal textbook for graduate students. It contains extensive student problem sets, and an answer book is available for instructors.

This combination of text and reference book describes the physical, plasma and chemical processes controlling the behaviour of ionospheres, upper atmospheres and exospheres. It summarises the structure, chemistry, dynamics and energetics of the terrestrial ionosphere and other solar system bodies, and discusses the processes, mechanisms and transport equations for solving fundamental research problems. This second edition incorporates new results, model developments and interpretations from the last 10 years. It includes the latest material on neutral atmospheres; the terrestrial ionosphere at low, middle and high latitudes; and planetary atmospheres and ionospheres, where results from recent space missions have yielded fresh data. Appendices outline physical constants, mathematical formulas, transport coefficients, and other important parameters for ionospheric calculations. This is an essential resource for researchers studying ionospheres, upper atmospheres, aeronomy and plasma physics. It is also an ideal textbook for graduate-level courses, with supplementary problem sets, and solutions for instructors at www.cambridge.org/9780521877060.

The theory and observations relating to electron temperatures in the F region of the ionosphere are reviewed. The review is divided into three basic parts. In the first part the theory concerning electron heating, cooling, and energy transport processes is reviewed, and all the relevant expressions are updated. In the second part the behavior of F region electron temperatures, as measured by satellites, rockets, and incoherent scatter radars, is discussed. This portion covers electron temperature variations with altitude, latitude, local time, season, geomagnetic activity, and solar cycle. The third part is primarily devoted to a discussion of the various attempts to compare measured and calculated F region electron temperatures.

In this review we attempt to present a unified picture of transport in multispecies gas mixtures. To accomplish this task, it is necessary to outline the mathematical structure of the transport equations. Starting from Boltzmann's equation, we derive a general system of transport equations using an approach that is valid for flow situations in which there are large temperature and drift velocity differences between the interacting species. However, this system of equations, which is obtained by taking velocity moments of the Boltzmann equation, does not constitute a closed set, since the equation governing the velocity moment of order r contains the velocity moment of order r + 1. To close the system of transport equations, it is therefore necessary to adopt an approximate expression for the species velocity distribution function. For near‐equilibrium flows, various levels of approximation are considered, including the 5‐, 8‐, 10‐, 13‐, and 20‐moment approximations. The procedure for obtaining closed sets of transport equations for far‐from‐equilibrium flows is also discussed. When the transport equations are ordered with respect to the collisional mean free path, the result is the Euler, Navier‐Stokes, or extended Navier‐Stokes equations depending upon whether terms proportional to the zeroth, first, or second power of the mean free path are retained. For a collisionless plasma the analogous expansion using the Larmor radius yields the Chew‐Goldberger‐Low (CGL) equations to zeroth order and the extended CGL equations to first order.

The ionosphere is a highly dynamic medium that exhibits weather disturbances at all latitudes, longitudes, and altitudes, and these disturbances can have detrimental effects on both military and civilian systems. In an effort to mitigate the adverse effects, we are developing a physics‐based data assimilation model of the ionosphere and neutral atmosphere called the Global Assimilation of Ionospheric Measurements (GAIM). GAIM will use a physics‐based ionosphere‐plasmasphere model and a Kalman filter as a basis for assimilating a diverse set of real‐time (or near real‐time) measurements. Some of the data to be assimilated include in situ density measurements from satellites, ionosonde electron density profiles, occultation data, ground‐based GPS total electron contents (TECs), two‐dimensional ionospheric density distributions from tomography chains, and line‐of‐sight UV emissions from selected satellites. When completed, GAIM will provide specifications and forecasts on a spatial grid that can be global, regional, or local. The primary output of GAIM will be a continuous reconstruction of the three‐dimensional electron density distribution from 90 km to geosynchronous altitude (35,000 km). GAIM also outputs auxiliary parameters, including NmF2, hmF2, NmE, hmE, and slant and vertical TEC. Furthermore, GAIM provides global distributions for the ionospheric drivers (neutral winds and densities, magnetospheric and equatorial electric fields, and electron precipitation patterns). In its specification mode, GAIM yields quantitative estimates for the accuracy of the reconstructed ionospheric densities.