Sökning: "solar magnetic fields"

Visar resultat 1 - 5 av 45 avhandlingar innehållade orden solar magnetic fields.

1. 1. Measuring the solar atmosphere

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

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

4. 3. Constraining magnetic heating in the solar chromosphere

   Författare :Roberta Morosin; Jaime de la Cruz Rodríguez; Elena Khomenko; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; magnetic fields; spectropolarimetry; Astronomy; astronomi;

   Sammanfattning : The chromospheric and coronal heating problems remain one of the foremost open questions in solar and stellar physics: how are the outer layers of the Sun heated from a few thousand kelvin in the photosphere to the million-degree corona? Radiation alone is not capable of transporting the required energy to explain observations from the inner layers. Phenomena associated with the presence of magnetic fields could provide the missing energy. LÄS MER

5. 4. Imaging spectropolarimetry of solar active regions

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

   Sammanfattning : 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. LÄS MER

7. 5. Investigating magnetic fields in the solar chromosphere

   Författare :Alexander Pietrow; Dan Kiselman; Jaime de la Cruz Rodr´ıguez; Oleg Kochukhov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; plage; Astronomy; astronomi;

   Sammanfattning : Solar plage has been the topic of many studies since its initial description in the mid 19th century, but as of yet it has not been understood to the point where we can reproduce all aspects of these active regions in quasi-realistic numerical models. To a large extent, this is caused by an incomplete understanding of the magnetic structure that drives the activity in these areas. LÄS MER