[1] Thunderstorm clouds may discharge directly to the ionosphere in spectacular luminous jets – the largest electric discharges of our planet. The properties of these “giants,” such as their polarity, conductivity, and currents, have been predicted by models, but are poorly characterized by measurements. A recent observation of a giant, fortuitously illuminated by an unusual sprite discharge in...

Ionospheric electron density data from the Sondrestrom incoherent scatter radar (ISR) have been used to characterize the structure of the F region ionosphere during ground-based LF/MF/HF receiver observations of natural ionospheric radio emissions known as auroral roar. In five out of six cases, the F region ionosphere has significant horizontal Ne gradient scale lengths (IVN/NI mi• < 120 km, m...

The Naval Research Laboratory (NRL) Sami2 is Another Model of the Ionosphere (SAMI2) and Sami3 Also a (SAMI3) ionosphere/plasmasphere codes have shown that thermosphere composition winds significantly affect H + outflows from topside ionosphere. In particular, O density inhibits upward diffusion ionosphere F layer, especially during solar maximum conditions. addition, quiet-time latitudinal ext...

The ionosphere is the largest remaining error source affecting GPS. It also has some of the least predictable spatial and temporal variations. As such the ionosphere becomes the determining factor in system performance for WAAS. Because the ionosphere cannot be observed at all places simultaneously, the confidence bound, termed the Grid Ionospheric Vertical Error (GIVE), can only be determined ...

An isolated plasma sheet flow burst took place at 22:02 UT, 1 September 2002, when the Cluster footpoint was located within the area covered by the Magnetometers-Ionospheric Radars-All-sky Cameras Large Experiment (MIRACLE). The event was associated with a clear but weak ionospheric disturbance and took place during a steady southward IMF interval, about 1 h preceding a major substorm onset. Mu...

An isolated plasma sheet flow burst took place at 22:02 UT, 1 September 2002, when the Cluster footpoint was located within the area covered by the Magnetometers-Ionospheric Radars-All-sky Cameras Large Experiment (MIRACLE). The event was associated with a clear but weak ionospheric disturbance and took place during a steady southward IMF interval, about 1 h preceding a major substorm onset. Mu...

Inductive coupling of a global magnetospheric model to a global ionospheric–thermospheric model is described. Existing schemes based on electrostatic coupling are valid for magnetospheric variability occurring on time scales of order 100 s or longer. The formulation developed here extends the validity of the coupling model to time scales of order 10 s, while retaining the physics of quasi-stati...

This chapter summarizes our current understanding of the ionosphere of Saturn. We give an overview of Saturn ionospheric science from the Voyager era to the present, with a focus on the wealth of new data and discoveries enabled by Cassini, including a massive increase in the number of electron density altitude profiles. We discuss recent ground-based detections of the effect of “ring rain” on ...