Search for dissertations about: "Solar observations"

Showing result 1 - 5 of 124 swedish dissertations containing the words Solar observations.

  2. 1. Electrostatic plasma waves associated with collisionless magnetic reconnection : Spacecraft observations

    Author : Konrad Steinvall; Yuri Khotyaintsev; Daniel Graham; Andris Vaivads; Jonathan Rae; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magnetic reconnection; Plasma waves; Electron holes; Solar wind; Magnetosphere; Magnetospheric Multiscale; Solar Orbiter; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Abstract : Magnetic reconnection is a fundamental plasma process where changes in magnetic field topology result in explosive energy conversion, plasma mixing, heating, and energization. In geospace, magnetic reconnection couples the Earth’s magnetosphere to the solar wind plasma, enabling plasma transport across the magnetopause. READ MORE

  4. 2. Measuring the solar atmosphere

    Author : Jaime de la Cruz Rodríguez; Göran Scharmer; Dan Kiselman; Mats Carlsson; Gianna Cauzzi; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; Chromosphere; Spectropolarimetry; Solar observations; Spectral lines; Solar magnetic fields; Astronomy; Astronomi; Astronomy; astronomi;

    Abstract : The new CRISP filter at the Swedish 1-m Solar Telescope provides opportunities for observing the solar atmosphere with unprecedented spatial resolution and cadence. In order to benefit from the high quality of observational data from this instrument, we have developed methods for calibrating and restoring polarized Stokes images, obtained at optical and near infrared wavelengths, taking into account field-of-view variations of the filter properties. READ MORE

  5. 3. Magnetic Reconnection in Space Plasmas : Cluster Spacecraft Observations

    Author : Alessandro Retinò; Mats André; Andris Vaivads; Bengt U. Ö. Sonnerup; Uppsala universitet; []
    Keywords : Space and plasma physics; space physics; plasma astrophysics; plasma physics; transport processes; boundary layers; magnetic reconnection; turbulence; particle acceleration; solar system; magnetospheres; Rymd- och plasmafysik;

    Abstract : Magnetic reconnection is a universal process occurring at boundaries between magnetized plasmas, where changes in the topology of the magnetic field lead to the transport of charged particles across the boundaries and to the conversion of electromagnetic energy into kinetic and thermal energy of the particles. Reconnection occurs in laboratory plasmas, in solar system plasmas and it is considered to play a key role in many other space environments such as magnetized stars and accretion disks around stars and planets under formation. READ MORE

  6. 4. 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

  7. 5. Imaging spectropolarimetry of solar active regions

    Author : Gautam Narayan; Göran Scharmer; Rolf Schlichenmaier; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; Spectropolarimetry; Solar magnetic fields; Sunspots; Plages; Solar physics; Solfysik; Astronomy; astronomi;

    Abstract : Solar magnetic fields span a wide range of spatial scales from sunspots and plages to magnetic bright points. A clear understanding of the physical processes underlying the evolution of these magnetic features requires high-resolution spectropolarimetric observations of solar active regions and comparisons with synthetic data from simulations. READ MORE