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

B. Eliasson, T. B. Leyser

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

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.
LanguageEnglish
Pages1019-1030
Number of pages12
JournalAnnales Geophysicae
Volume33
DOIs
Publication statusPublished - 19 Aug 2015

Fingerprint

striation
ionospheres
leakage
pumping
ionosphere
electromagnetism
ionospherics
electromagnetic wave
electromagnetic radiation
turbulence
magnetic field
plasma
thresholds
radiation
magnetic fields

Keywords

  • upper hybrid waves
  • Z mode waves
  • striations
  • ionosphere

Cite this

@article{0c24e6b9dfe34b259d9feea315aa10d8,
title = "Numerical study of upper hybrid to Z mode leakage during electromagnetic pumping of groups of striations in the ionosphere",
abstract = "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.",
keywords = "upper hybrid waves, Z mode waves, striations, ionosphere",
author = "B. Eliasson and Leyser, {T. B.}",
year = "2015",
month = "8",
day = "19",
doi = "10.5194/angeo-33-1019-2015",
language = "English",
volume = "33",
pages = "1019--1030",
journal = "Annales Geophysicae",
issn = "0992-7689",

}

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

In: Annales Geophysicae, Vol. 33, 19.08.2015, p. 1019-1030.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Numerical study of upper hybrid to Z mode leakage during electromagnetic pumping of groups of striations in the ionosphere

AU - Eliasson, B.

AU - Leyser, T. B.

PY - 2015/8/19

Y1 - 2015/8/19

N2 - 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.

AB - 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.

KW - upper hybrid waves

KW - Z mode waves

KW - striations

KW - ionosphere

UR - http://www.ann-geophys.net/33/1019/2015/angeo-33-1019-2015.html

U2 - 10.5194/angeo-33-1019-2015

DO - 10.5194/angeo-33-1019-2015

M3 - Article

VL - 33

SP - 1019

EP - 1030

JO - Annales Geophysicae

T2 - Annales Geophysicae

JF - Annales Geophysicae

SN - 0992-7689

ER -