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Scherliess & Fejer 1997
Scherliess, L. and Fejer, B.G. (1997). Storm time dependence of equatorial disturbance dynamo zonal electric fields. Journal of Geophysical Research 102: doi: 10.1029/97JA02165. issn: 0148-0227.

We use Jicamarca radar observations of F region vertical plasma drifts and auroral electrojet indices during 1968--1988 to study the characteristics and temporal evolution of equatorial disturbance dynamo zonal electric fields. These electric fields result from the dynamo action of storm time winds and/or thermospheric composition changes driven by enhanced energy deposition into the high-latitude ionosphere during geomagnetically active conditions. The equatorial vertical drift perturbations last for periods of up to 30 hours after large increases in the high-latitude currents. On the average, this process can be described by two basic components with time delays of about 1--12 hours and 22--28 hours between the high-latitude current enhancements and the equatorial velocity perturbations. Our data indicate strong coupling between dynamo processes with different timescales. The short-term disturbance dynamo drives upward equatorial drifts (eastward electric fields) at night with largest amplitudes near sunrise and small downward drifts during the day. These perturbation drifts are in good agreement with results from the Blanc-Richmond disturbance dynamo theory. The dynamo process with time delays of about a day drives upward drift velocities at night with largest values near midnight and downward drifts in the sunrise-noon sector. In this case, the amplitudes of the disturbance drifts maximize during geomagnetically quiet times preceded by strongly disturbed conditions. We also present results of a new equatorial storm time dependent empirical model which illustrate the characteristics of the vertical disturbance dynamo drifts.¿ 1997 American Geophysical Union

BACKGROUND DATA FILES

Abstract

Keywords
Ionosphere, Current systems, Ionosphere, Electric fields, Ionosphere, Equatorial ionosphere, Magnetospheric Physics, Storms and substorms
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
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