Aspect sensitivity of equatorial electrojet irregularities and theoretical implications

Simple item page
dc.contributor.authorKudeki, Erhan
dc.contributor.authorFarley, Donald T.
dc.date.accessioned2018-07-06T17:01:49Z
dc.date.available2018-07-06T17:01:49Z
dc.date.issued1989-01-01
dc.description.abstractWe used a multi baseline 50-MHz radar interferometer at the Jicamarca Radio Observatory to study the dependence of echo strength on the aspect angle, the angle of arrival relative to normal to the geomagnetic field. We observed rms values of this angle in the range 0.1–0.4, which implies an aspect sensitivity somewhat greater than the nominal 10 dB/deg often quoted for auroral echoes. The technique has sufficient resolution to allow deviations from normal of less than 0.1 to be measured fairly easily, and we were able to determine variations of the aspect sensitivity with altitude, Doppler shift, and electrojet conditions. During weakly driven periods, when only type 2 echoes were observed, the width, or rms angular deviation from normal, decreased monotonically with increasing altitude, as simple linear theory would suggest, but the variation was less rapid than the variation of νe/Ωe, especially on the bottomside of the electrojet. A particularly interesting observation was that, during strongly driven type 1 conditions, there was a pronounced variation of width with Doppler shift. The width for small phase velocities was sometimes more than twice that at the ion-acoustic velocity. We believe that this broadening is due to nonlinear three-wave mode coupling which produces a reverse cascade of energy from short wavelengths to long and an increase in the mean aspect angle. Such a cascade represents an increase in the effective diffusion coefficient for the short wavelength waves and so could provide an explanation alternative to that of the anomalous collision process of Sudan (1983) for the limitation of the type 1 phase velocity at the ion-acoustic velocity.es_ES
dc.description.peer-reviewPor pareses_ES
dc.formatapplication/pdfes_ES
dc.identifier.citationKudeki, E., & Farley, D. T. (1989). Aspect sensitivity of equatorial electrojet irregularities and theoretical implications.==$Journal of Geophysical Research: Space Physics, 94$==(A1), 426-434. https://doi.org/10.1029/JA094iA01p00426es_ES
dc.identifier.doihttps://doi.org/10.1029/JA094iA01p00426es_ES
dc.identifier.journalJournal of Geophysical Research: Space Physicses_ES
dc.identifier.urihttp://hdl.handle.net/20.500.12816/1731
dc.language.isoenges_ES
dc.publisherAmerican Geophysical Uniones_ES
dc.relation.ispartofurn:issn:2169-9380
dc.rightsinfo:eu-repo/semantics/restrictedAccesses_ES
dc.subjectEquatorial electrojetes_ES
dc.subjectEchoeses_ES
dc.subjectInterferometryes_ES
dc.subject.ocdehttp://purl.org/pe-repo/ocde/ford#1.05.01es_ES
dc.titleAspect sensitivity of equatorial electrojet irregularities and theoretical implicationses_ES
dc.typeinfo:eu-repo/semantics/articlees_ES

Files

License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download

Collections

Artículos Científicos