Search for dissertations about: "auroral region"

Showing result 1 - 5 of 19 swedish dissertations containing the words auroral region.

  1. 1. The importance of waves in space plasmas Examples from the auroral region and the magnetopause

    University dissertation from Umeå : Fysik

    Author : Gabriella Stenberg; Umeå universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; Plasma waves; magnetospheric physics; magnetopause; auroral region; wave distribution function; space exploration; reconnection; current tubes; Rymd- och plasmafysik; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik; rymdfysik; Space Physics;

    Abstract : This thesis discusses the reasons for space exploration and space science. Space plasma physics is identified as an essential building block to understand the space environment and it is argued that observation and analysis of space plasma waves is an important approach.Space plasma waves are the main actors in many important processes. READ MORE

  2. 2. Investigations of auroral electric fields and currents

    University dissertation from Stockholm : KTH

    Author : Tommy Johansson; KTH.; [2007]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; auroral physics; auroral electric fields; auroral potential structures; auroral particle acceleration; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik;

    Abstract : The Cluster spacecraft have been used to investigate auroral electric fields and field-aligned currents (FACs) at geocentric distances between 4 and 7 Re. The electric fields have been measured by the EFW instrument, consisting of two pairs of spherical probes, and the FACs have been calculated from measurements of the magnetic field by the FGM fluxgate magnetometer. READ MORE

  3. 3. Numerical modeling of auroral processes

    University dissertation from Umeå : Fysik

    Author : Jörgen Vedin; Umeå universitet.; [2007]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; space plasma physics; auroral acceleration region; auroral current circuit; Alfvén waves; parallel electric fields; equation of state; fluid simulation; PIC simulation; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik;

    Abstract : One of the most conspicuous problems in space physics for the last decades has been to theoretically describe how the large parallel electric fields on auroral field lines can be generated. There is strong observational evidence of such electric fields, and stationary theory supports the need for electric fields accelerating electrons to the ionosphere where they generate auroras. READ MORE

  4. 4. Cluster Observations and Theoretical Explanations of Broadband Waves in the Auroral Region

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Marie Backrud; Uppsala universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; ion acoustic waves; auroral region; anomalous resistivity; Cluster; Rymd- och plasmafysik; NATURAL SCIENCES Physics Geocosmophysics and plasma physics Space physics; NATURVETENSKAP Fysik Geokosmofysik och plasmafysik Rymdfysik;

    Abstract : Broadband extremely low-frequency wave emissions below the ion plasma frequency have been observed by a number of spacecraft and rockets on auroral field lines. The importance of these broadband emissions for transverse ion heating and electron acceleration in the auroral regions is now reasonably well established. READ MORE

  5. 5. Cluster in situ studies of the auroral acceleration region

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Bin Li; KTH.; [2014]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cluster; Aurora acceleration region; Physics; Fysik;

    Abstract : This thesis addresses a central topic in auroral physics, namely particle accelerationproducing intense aurora as well as energetic plasma outflow. Cluster satellitemeasurements of electric and magnetic fields, electrons and ions, collected across auroralfield lines, are used to study various aspects of the quasi-static auroral accelerationregion (AAR), its relation to the auroral density cavity, and the relative role of quasistaticand Alfvénic acceleration for producing aurora. READ MORE