Evidence and effects of a wave-driven nonlinear current in the equatorial electrojet
Item
Title (Dublin Core)
Evidence and effects of a wave-driven nonlinear current in the equatorial electrojet
Description (Dublin Core)
Ionospheric two-stream waves and gradient-drift waves nonlinearly drive a large-scale (D.C.) current in the <i>E</i>-region ionosphere. This current flows parallel to, and with a comparable magnitude to, the fundamental Pedersen current. Evidence for the existence and magnitude of wave-driven currents derives from a theoretical understanding of <i>E</i>-region waves, supported by a series of nonlinear 2D simulations of two-stream waves and by data collected by rocket instruments in the equatorial electrojet. Wave-driven currents will modify the large-scale dynamics of the equatorial electrojet during highly active periods. A simple model shows how a wave-driven current appreciably reduces the horizontally flowing electron current of the electrojet. This reduction may account for the observation that type-I radar echoes almost always have a Doppler velocity close to the acoustic speed, and also for the rocket observation that electrojet regions containing gradient-drift waves do not appear also to contain horizontally propagating two-stream waves. Additionally, a simple model of a gradient-drift instability shows that wave-driven currents can cause nonsinusoidal electric fields similar to those measured <i>in situ</i>.
Creator (Dublin Core)
Oppenheim, M.
Date (Dublin Core)
2018-09-27
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.1007/s00585-997-0899-z
https://angeo.copernicus.org/articles/15/899/1997/
Source (Dublin Core)
eISSN: 1432-0576
Language (Dublin Core)
eng
