Sökning: "solar wind"

Visar resultat 6 - 10 av 222 avhandlingar innehållade orden solar wind.

  1. 6. Solar Wind and Geomagnetic Activity - Predictions Using Neural Networks

    Författare :Hans Gleisner; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; kosmisk kemi; rymdvetenskap; magnetosphere; solar wind; space weather; geomagnetic activity; geomagnetism; ring current; auroral electrojet; neural networks; forecasting; Astronomy; space research; Astronomi; cosmic chemistry; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi; Fysicumarkivet A:2000:Gleisner;

    Sammanfattning : This thesis shows how artificial neural networks (ANNs) can be applied to predict geomagnetic activity from solar-wind data. It introduces and summarizes five papers where development of ANN models are reported, and where predictions of geomagnetic activity are discussed. LÄS MER

  2. 7. Plasma Interactions with Icy Bodies in the Solar System

    Författare :Jesper Lindkvist; Mats Holmström; Martin Wieser; Elias Roussos; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plasma interactions; icy bodies; solar system; space physics; plasma physics; hybrid model; numerical model; solar wind; magnetosphere; sub-Alfvénic; subsonic; non-collisional; atmosphereless; exosphere; coma; subsurface ocean; induction; magnetic dipole; pick-up ion; mass-loading; moon; natural satellite; dwarf planet; comet; Jupiter; Jovian; Callisto; Ceres; 67P; Churyumov-Gerasimenko; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : Here I study the “plasma interactions with icy bodies in the solar system”, that is, my quest to understand the fundamental processes that govern such interactions. By using numerical modelling combined with in situ observations, one can infer the internal structure of icy bodies and their plasma environments. LÄS MER

  3. 8. Combining Models of Coronal Mass Ejections and Solar Dynamos

    Författare :Jörn Warnecke; Axel Brandenburg; Juri Toomre; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetohydrodynamics; convection; turbulence; solar dynamo; solar rotation; solar activity; coronal mass ejections; Astronomy; astronomi;

    Sammanfattning : Observations show that Coronal Mass Ejections (CMEs) are associated with twisted magnetic flux configurations. Conventionally, CMEs are modeled by shearing and twisting the footpoints of a certain distribution of magnetic flux at the solar surface and letting it evolve at the surface. LÄS MER

  4. 9. Solar Wind Proton Interactions with Lunar Magnetic Anomalies and Regolith

    Författare :Charles Lue; Yoshifumi Futaana; Stas Barabash; Urs Mall; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; the Moon; solar wind; magnetic anomalies; regolith; space physics; plasma physics; particle-surface interactions; mini-magnetospheres; energetic neutral atoms; Space Physics; rymdfysik;

    Sammanfattning : The lunar space environment is shaped by the interaction between the Moon and the solar wind. In the present thesis, we investigate two aspects of this interaction, namely the interaction between solar wind protons and lunar crustal magnetic anomalies, and the interaction between solar wind protons and lunar regolith. LÄS MER

  5. 10. Space Weather Physics, Prediction and classification of solar wind structures and geomagnetic activity using artificial neural networks

    Författare :Peter Wintoft; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomi; cosmic chemistry; space research; Astronomy; solar magnetic fields; space weather; solar wind; magnesphere; artificial neural networks; geomagnetic activity; rymdvetenskap; kosmisk kemi; Fysicumarkivet A:1997:Wintoft;

    Sammanfattning : This thesis concerns the application of artificial neural network techniques to space weather physics. The networks applied include multi-layer error-backpropagation, radial basis function, and self-organized maps. LÄS MER