del Pozo, C. F. (1994) Polarization electric field and Farley-Buneman instability during a precipitation event. Journal of Atmospheric and Terrestrial Physics, 56 (4). pp. 509-523.Full text not available from this repository.
An anomalous polarization electric field may be set-up in the lower auroral E-region in response to an electron precipitation event during unstable electrojet conditions. For instance, observations during post-midnight to early morning hours on 06–07 June 1990, using the EISCAT radar facility in Scandinavia, show that the in-situ dynamics of the E-region ionization may be radically affected by the presence of the Farley-Buneman instability. In this case, the measured ion drifts at 105 km height are exceptionally strong and comparable in magnitude with the E × B-drift in the F-region, mapped along the same magnetic fieldline. In this paper we present a model to explain the main features of these observations. We assume a simple relaxation model for the E-region ionization generated by an instantaneous electron precipitation event during diffuse aurora conditions and in the presence of the Farley-Buneman instability. In these conditions and for times smaller than the ionization lifetime (tens of seconds to a few minutes), the induced polarization electric field to restore charge quasi-neutrality may radically increase the ion drift velocity, and effectively decouple the ion motion from the dynamics of the neutral atmosphere.
|Journal or Publication Title:||Journal of Atmospheric and Terrestrial Physics|
|Uncontrolled Keywords:||Polar ionosphere ; Ionospheric E region ; Electric field ; Polarization ; Buneman Farley instability ; Particle precipitation ; Drift velocity|
|Subjects:||G Geography. Anthropology. Recreation > GE Environmental Sciences|
|Departments:||Faculty of Science and Technology > Lancaster Environment Centre|
|Deposited On:||20 Jan 2009 12:56|
|Last Modified:||04 Nov 2015 00:12|
Actions (login required)