Sökning: "Cluster spacecraft"

Visar resultat 11 - 15 av 19 avhandlingar innehållade orden Cluster spacecraft.

  1. 11. Low-Energy Ion Escape from the Terrestrial Polar Regions

    Författare :Erik Engwall; Anders I. Eriksson; Mats André; Thomas Moore; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; space physics; ion outflow; polar wind; auroral upflows; atmospheric escape; magnetotail lobes; spacecraft wake; electric field measurements; Geocosmophysics and plasma physics; Geokosmofysik och plasmafysik; Space and Plasma Physics; rymd- och plasmafysik;

    Sammanfattning : The contemporary terrestrial atmosphere loses matter at a rate of around 100,000 tons per year. A major fraction of the net mass loss is constituted by ions, mainly H+ and O+, which escape from the Earth’s ionosphere in the polar regions. LÄS MER

  3. 12. Ion dynamics and structure of collisionless shocks

    Författare :Andreas Johlander; Andris Vaivads; Rami Vainio; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Shock waves are responsible for slowing down and heating supersonic flows. In collisionless space plasmas, shocks are able to accelerate particles to very high energies. We study injection of suprathermal ions at Earth’s quasi- parallel shock using high time resolution data from the Cluster spacecraft. LÄS MER

  4. 13. Investigations of auroral electric fields and currents

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

    Sammanfattning : 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. LÄS MER

  5. 14. Energy Transfer and Conversion in the Magnetosphere-Ionosphere System

    Författare :Lisa Rosenqvist; Stephan Buchert; Andris Vaivads; Mike Lockwood; Uppsala universitet; []
    Nyckelord :Space and plasma physics; solar system; space physics; magnetospheric physics; plasma physics; magnetic storms; substorms; boundary layers; magnetic reconnection; energy conversion; space weather; Rymd- och plasmafysik;

    Sammanfattning : Magnetized planets, such as Earth, are strongly influenced by the solar wind. The Sun is very dynamic, releasing varying amounts of energy, resulting in a fluctuating energy and momentum exchange between the solar wind and planetary magnetospheres. LÄS MER

  7. 15. Solar wind interaction with the terrestrial magnetopause

    Författare :Lars-Göran Westerberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : The solar wind interaction with the terrestrial magnetosphere is a source for many spectacular phenomena on or close the Earth's surface. A key question during the last fifty years have been how the solar wind plasma can enter the terrestrial magnetic shield represented by the magnetosphere and its outermost layer called the magnetopause. LÄS MER