Sökning: "Rymdfysik"

Visar resultat 21 - 25 av 240 avhandlingar innehållade ordet Rymdfysik.

  1. 21. VLF and ULF Waves Associated with Magnetospheric Substorms

    Författare :Andrew Collier; Lars Blomberg; James McKenzie; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Subtorms; Magnetosphere; VLF waves; ULF waves; Space physics; Rymdfysik;

    Sammanfattning : A magnetospheric substorm is manifested in a variety of phenomena observed both in space and on the ground. Two electromagnetic signatures are the Substorm Chorus Event (SCE) and Pi2 pulsations. The SCE is a Very Low Frequency (VLF) radio phenomenon observed on the ground after the onset of the substorm expansion phase. LÄS MER

  3. 22. Fine-scale morphology and spectral characteristics of active aurora

    Författare :Hanna Dahlgren; Göran Marklund; Nickolay Ivchenko; Kari Kaila; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aurora; Space physics; Rymdfysik;

    Sammanfattning : Ground-based and in-situ observations of the aurora demonstrate an extreme richness in fine structure, with spatial scales down to tens of metres and time variations occurring on a fraction of a second. To further our understanding of the aurora, it is esssential to understand the mechanisms responsible for the small-scale structuring, since this is an intrinsic property of the auroral plasma. LÄS MER

  4. 23. There and back again... An Earth magneto-tale : understanding plasma flows in the magnetotail

    Författare :Alexandre De Spiegeleer; Maria Hamrin; Herbert Gunell; Timo Pitkänen; Colin Forsyth; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma dynamics; Earth magnetosphere; magnetotail; plasma sheet flows; oscillatory flows; burst bulk flows; tailward flows; rymdfysik; Space Physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : On average, the Earth's magnetotail plasma sheet seems to be a calm region of the magnetosphere where the plasma moves slowly towards Earth. However, the plasma sheet actually hosts many phenomena, some of which can affect Earth. LÄS MER

  5. 24. Solitary waves and enhanced incoherent scatter ion lines

    Författare :Jonas Ekeberg; Lars Eliasson; Kristof Stasiewicz; Jan Trulsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasma waves and instabilities; nonlinear phenomena; solitons and solitary waves; ionosphere; Sun: corona; incoherent scatter radar; MHD; plasmavågor och instabiliteter; ickelinjära fenomen; solitoner och solitära vågor; jonosfär; solen: korona; inkoherent spridningsradar; MHD; Geocosmophysics and plasma physics; Geokosmofysik och plasmafysik; Space physics; Rymdfysik; Plasma physics; Plasmafysik; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos; fysik; Physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : This thesis addresses solitary waves and their significance for auroral particle acceleration, coronal heating and incoherent scatter radar spectra. Solitary waves are formed due to a balance of nonlinear and dispersive effects. LÄS MER

  7. 25. Multi-point Measurements of Ultra Low Frequency Waves in the Terrestrial Magnetosphere

    Författare :Tommy Eriksson; Lars Blomberg; Ian Mann; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik;

    Sammanfattning : Waves in the mHz frequency range are prominent features of the terrestrial magnetosphere. In this frequency range the waves have wavelengths comparable to the lengths of the geomagnetic field lines. The waves are then standing waves along closed field lines with endpoints in the southern and northern ionosphere. LÄS MER