Sökning: "field-aligned irregularities"

Hittade 2 avhandlingar innehållade orden field-aligned irregularities.

  1. 1. Interaction between Electromagnetic Waves and Localized Plasma Oscillations

    Författare :Jan-Ove Hall; Thomas Leyser; Jan Trulsen; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma physics; radio waves; ionospheric modification; density depleations; field-aligned irregularities; lower hybrid solitary structures; lower hybrid cavities; Z mode waves; magnetosonic waves; scattering; mode conversion; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). LÄS MER

  2. 2. Opening New Radio Windows and Bending Twisted Beams

    Författare :Erik Nordblad; Thomas B. Leyser; Kristof Stasiewicz; Vladimir Pavlenko; Paul A. Bernhardt; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Orbital angular momentum; Hall effect; Nonparaxial beam; Geometrical optics; High frequency radio waves; Ray tracing; Magnetic zenith effect; Ionospheric irregularities; Wave propagation; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : In ground based high frequency (HF) radio pumping experiments, absorption of ordinary (O) mode pump waves energises the ionospheric plasma, producing optical emissions and other effects. Pump-induced or natural kilometre-scale field-aligned density depletions are believed to play a role in self-focussing phenomena such as the magnetic zenith (MZ) effect, i. LÄS MER