Search for dissertations about: "auroral region"

Showing result 6 - 10 of 19 swedish dissertations containing the words auroral region.

  2. 6. Auroral Electric Fields From Satellite Observations and Numerical Modelling

    Author : Tomas Karlsson; KTH; []
    Keywords : Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. READ MORE

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

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

    Abstract : 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. READ MORE

  5. 8. Cluster investigations of the extent and altitude distribution of the auroral density cavity

    Author : Love Alm; Göran T. Marklund; Tomas Karlsson; Rickard Lundin; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Auroral density cavity; auroral accelaration; Cluster; in situ observation; electron density; pseudo altitude; Physics; Fysik;

    Abstract : The auroral density cavity constitutes the boundary between the cold, dense ionospheric plasma and the hot, tenuous plasma sheet plasma. The auroral density cavity is characterized by low electron density and particle populations modified by parallel electric fields. READ MORE

  6. 9. Cluster multi-point observations of the auroral acceleration region

    Author : Soheil Sadeghi; Göran T. Marklund; Andris Vaivads; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Abstract : .... READ MORE

  7. 10. Satellite observations of auroral acceleration processes

    Author : Lars Eliasson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Aurora; particle acceleration; space plasma; magnetosphere; ionosphere; polar cap; satellite observations;

    Abstract : Measurements with satellite and sounding rocket borne instruments contain important information on remote and local processes in regions containing matter in the plasma state. The characteristic features of the particle distributions can be used to explain the morphology and dynamics of the different plasma populations. READ MORE