Regional, scale size, and interplanetary magnetic field variability of magnetic field and ion drift structures in the high-latitude ionosphere

Citation
Jp. Keady et Ra. Heelis, Regional, scale size, and interplanetary magnetic field variability of magnetic field and ion drift structures in the high-latitude ionosphere, J GEO R-S P, 104(A1), 1999, pp. 199-212
Citations number
45
Categorie Soggetti
Space Sciences
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
ISSN journal
21699380 → ACNP
Volume
104
Issue
A1
Year of publication
1999
Pages
199 - 212
Database
ISI
SICI code
0148-0227(19990101)104:A1<199:RSSAIM>2.0.ZU;2-I
Abstract
Using data from the Dynamics Explorer 2 satellite's ion drift meter and mag netometer, we have examined fluctuations in the high-latitude velocity and magnetic field structure to better understand the coupling between the magn etosphere and ionosphere. Our study examines perturbations in the frequency range from 0.25 to 8 Hz, equivalent to static scale sizes between about 30 and 1 km. Seasonal variations in the perturbations at large-scale sizes in dicate that magnetosphere-ionosphere coupling is dominated by static curren ts. These static currents display behavior consistent with a current driver in the auroral zone and a voltage driver in the cusp. In the frequency ran ge 0.6 to 1.5 Hz the magnetosphere-ionosphere coupling is significantly inf luenced by Alfven waves with the high-frequency range extending up to 8 Hz in the cusp.