AIM-E: E-Region Auroral Ionosphere Model

Hf-pump-induced Parametric Instabilities in the Auroral E-region

In November 1999 the EISCAT high-power, high-frequency (HF) facility located near Tromsø, Norway, was used to create artificial plasma turbulence in the ionosphere. During the experiment the EISCAT 224 MHz radar and sometimes the 931 MHz radar were used to obtain measurements of incoherent scatter ion and plasma lines, and artificially enhanced spectra of E-region plasma waves were measured for...

Type-1 echoes from the mid-latitude E-Region ionosphere

This paper presents more data on the properties of type-1 irregularities in the nighttime midlatitude E-region ionosphere. The measurements were made with a 50-MHz Doppler radar system operating in Crete, Greece. The type-1 echoes last from several seconds to a few minutes and are characterized by narrow Doppler spectra with peaks corresponding to wave phase velocities of 250–350 m/s. The avera...

A Wave-driven Nonlinear Current in the E-region Ionosphere

Ionospheric two-stream waves and gradient-drift waves nonlinearly drive a large-scale (D.C.) current in the E-region ionosphere. This current ows parallel to, and with a comparable magnitude to, the fundamental Pedersen current. The underlying mechanism is quite simple. E-region plasma waves generate oscillating electric elds causing electrons to ~ E ~ B drift perpendicular to the wave's propag...

Plasma Lines in the Auroral E Layer

A classification of spectral populations observed in HF radar backscatter from the E region auroral electrojets

Observations of HF radar backscatter from the auroral electrojet E region indicate the presence of five major spectral populations, as opposed to the two predominant spectral populations, types I and II, observed in the VHF regime. The Doppler shift, spectral width, backscatter power, and flow angle dependencies of these five populations are investigated and described. Two of these populations ...