Search for dissertations about: "auroral particle acceleration"

Showing result 1 - 5 of 9 swedish dissertations containing the words auroral particle acceleration.

2. 1. Investigations of auroral electric fields and currents

   Author : Tommy Johansson; Göran Marklund; Kristina Lynch; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; auroral physics; auroral electric fields; auroral potential structures; auroral particle acceleration; Space physics; 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

4. 2. 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

5. 3. Numerical modeling of auroral processes

   Author : Jörgen Vedin; Kjell Rönnmark; Robert Lysak; Umeå universitet; []
   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; Space physics; 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

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

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

   Abstract : .... READ MORE

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

   Author : Bin Li; Göran Marklund; Stein Haaland; KTH; []
   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