 |
| Titel |
The relationship between electric fields, conductances and currents in the high-latitude ionosphere: a statistical study using EISCAT data |
| VerfasserIn |
J. A. Davies, Mark Lester |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 17, no. 1 ; Nr. 17, no. 1, S.43-52 |
| Datensatznummer |
250013643
|
| Publikation (Nr.) |
 copernicus.org/angeo-17-43-1999.pdf |
|
|
|
|
|
| Zusammenfassung |
The relationship between electric fields,
height-integrated conductivities and electric currents in the high-latitude
nightside electrojet region is known to be complex. The tristatic nature of the
EISCAT UHF radar facility provides an excellent means of exploring this
interrelationship as it enables simultaneous estimates to be made of the full
electric field vector and the ionospheric Hall and Pedersen conductances,
further allowing the determination of both field-perpendicular electric current
components. Over 1300 h of common programme observations by the UHF radar system
provide the basis of a statistical study of electric fields, conductances and
currents in the high-latitude ionosphere, from which preliminary results are
presented. Times at which there is significant solar contribution to the
ionospheric conductances have been excluded by limiting the observations
according to solar zenith angle. Initial results indicate that, in general, the
times of peak conductance, identified from the entire set of EISCAT
observations, do not correspond to the times of the largest electric field
values; the relative contribution of ionospheric conductance and electric field
to the electrojet currents therefore depends critically on local time, a
conclusion which corroborates work by previous authors. Simultaneous
measurements confirm a tendency for a decrease in both Hall and Pedersen
conductances to be accompanied by an increase in the electric field, at least
for moderate and large electric field value, a tendency which is also identified
to some extent in the ratio of the conductances, which acts as an indicator of
the energy of precipitating particles.
Key words. Ionosphere (auroral ionosphere; electric
fields and currents) |
| |
|
| Teil von |
|
|
|
|
|
|
|
|