Search for dissertations about: "solar dynamo"

Showing result 1 - 5 of 10 swedish dissertations containing the words solar dynamo.

  2. 1. Combining Models of Coronal Mass Ejections and Solar Dynamos

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

    Abstract : 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. READ MORE

  4. 2. Formation of solar bipolar regions : Magnetic flux concentrations from suction of the negative effective magnetic pressure instability

    Author : Illa Rivero Losada; Axel Brandenburg; Matthias Rempel; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magnetohydrodynamics MHD ; turbulence; dynamo; Sun: magnetic fields; Sun: rotation; Sun: activity; Sun: dynamo; Astronomy; astronomi;

    Abstract : Sunspots stand out on the visible solar surface. They appear as dark structures evolving and changing over time. They host energetic and violent events, like coronal mass ejections and flares, and concentrate strong magnetic fields. READ MORE

  5. 3. Origin of solar surface activity and sunspots

    Author : Sarah Jabbari; Axel Brandenburg; Laurene Jouve; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magneto-hydrodynamics; solar physics; dynamo theory; Astronomy; astronomi;

    Abstract : Sunspots and active regions are two of the many manifestations of the solar magnetic field. This field plays an important role in causing phenomena such as coronal mass ejections, flares, and coronal heating. Therefore, it is important to study the origin of sunspots and active regions and determine the underlying mechanism which creates them. READ MORE

  6. 4. From mean-field hydromagnetics to solar magnetic flux concentrations

    Author : Koen Kemel; Axel Brandenburg; Alexander Ruzmaikin; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; magneto-hydrodynamics; solar physics; turbulence; Astronomy; astronomi;

    Abstract : The main idea behind the work presented in this thesis is to investigate if it is possible to find a mechanism that leads to surface magnetic field concentrations and could operate under solar conditions without postulating the presence of magnetic flux tubes rising from the bottom of the convection zone, a commonly used yet physically problematic approach.In this context we study the ‘negative effective magnetic pressure effect’: it was pointed out in earlier work (Kleeorin et al. READ MORE

  7. 5. Origin of solar surface activity and sunspots

    Author : SARAH JABBARI; AXEL BRANDENBURG; Vasilis Archontis; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun-Solar activity-Sunspots; teoretisk astrofysik; Theoretical Astrophysics;

    Abstract : In the last few years, there has been significant progress in the development of a new model for explaining magnetic flux concentrations, by invoking the negative effective magnetic pressure instability (NEMPI) in a highly stratified turbulent plasma. According to this model, the suppression of the turbulent pressure by a large-scale magnetic field leads to a negative contribution of turbulence to the effective magnetic pressure (the sum of non-turbulent and turbulent contributions). READ MORE