Numerical study of upper hybrid to Z-mode leakage during electromagnetic pumping of groups of striations in the ionosphere

Eliasson, B.; Leyser, T. B.

We investigate numerically the interaction between ionospheric magnetic field-aligned density striations and a left-hand circularly polarized ( L)-mode wave. The L-mode wave is scattered into upper hybrid (UH) waves which are partially trapped in the striations, but leak energy to electromagnetic waves in the Z-mode branch. For small-amplitude (1 %) striations, this loss mechanism leads to a significant reduction in amplitude of the UH waves. For several striations organized in a lattice, the leaking of Z-mode waves is compensated by influx of Z-mode radiation from neighboring striations, leading to an increased amplitude of the weakly trapped UH waves. For large-amplitude (10 %) striations the trapped UH waves rapidly increase in amplitude far beyond the threshold for parametric instabilities, and the Z-mode leakage is less important. The results have relevance for the growth of striations and the onset of UH and lower hybrid turbulence during electromagnetic high-frequency pumping of ionospheric plasma, which require large-amplitude UH waves.

Zitieren

Zitierform:

Eliasson, B. / Leyser, T. B.: Numerical study of upper hybrid to Z-mode leakage during electromagnetic pumping of groups of striations in the ionosphere. 2015. Copernicus Publications.

Zugriffsstatistik

Gesamt:
Volltextzugriffe:
Metadatenansicht:
12 Monate:
Volltextzugriffe:
Metadatenansicht:

Grafik öffnen

Rechte

Rechteinhaber: B. Eliasson

Nutzung und Vervielfältigung:

Export