Sökning: "small scale auroral structure"

Hittade 4 avhandlingar innehållade orden small scale auroral structure.

  1. 1. Alfven Waves and Spatio-Temporal Structuring in the Auroral Ionosphere

    Författare :Nickolay Ivchenko; KTH; []
    Nyckelord :dispersive alfrén waves; auroral particle acceleration; ionospheric alfvén resonator; auroral particle acceleration; small scale auroral structure; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 2. Multi-spectral analysis of fine scale aurora

    Författare :Hanna Dahlgren; Göran Marklund; Nickolay Ivchenko; Fred Sigernes; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Plasma physics; Plasmafysik; Optics; Optik;

    Sammanfattning : The Aurora Borealis is the visible manifestation of the complex plasma interaction between the solar wind and the Earth's magnetosphere and ionosphere. Ground based and in situ measurements demonstrate a prevalence of dynamic fine structure within auroral displays, with spatial scales down to tens of metres and time variations occurring on a fraction of a second. LÄS MER

  4. 3. Multi-Spacecraft Observations of the Auroral Acceleration Region

    Författare :Soheil Sadeghi; Göran T. Marklund; Andris Vaivads; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The two major agents for producing aurora are generally believed to be the quasi-static parallel electric fields, accelerating electrons in the auroral acceleration region (AAR), and Alfvén waves. The Cluster spacecraft quartet has made multi-spacecraft measurements in the AAR possible for the first time. LÄS MER

  5. 4. 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