Search for dissertations about: "Chromosphere"

Showing result 1 - 5 of 10 swedish dissertations containing the word Chromosphere.

2. 1. The dynamic chromosphere : Results and techniques with an observational approach

   Author : Carolina Robustini; Jorrit Leenaarts; Fernando Moreno Insertis; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; jets; sunspots; imaging; spectropolarimetry; Astronomy; astronomi;

   Abstract : The chromosphere is a critical interface between the relatively cold photosphere and the hot corona. Its landscape is rich in very dynamic phenomena such as jets, spicules, and surges, which are thought to play an important role in the heating of the Sun’s upper atmosphere. READ MORE

4. 2. The synthetic chromosphere : Results and techniques with a numerical approach

   Author : Johan Pires Bjørgen; Jorrit Leenaarts; Oskar Steiner; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; radiative transfer; numerical method; Astronomy; astronomi;

   Abstract : Realistic numerical simulations of the solar atmosphere can be used to interpret different phenomena observed on the solar surface. To gain insight into the atmospheric physical conditions, we compare the observations with 3D radiative magnetohydrodynamic models combined with forward modeling (radiative transfer). READ MORE

5. 3. Investigating magnetic fields in the solar chromosphere

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

   Abstract : 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. READ MORE

6. 4. Constraining magnetic heating in the solar chromosphere

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

   Abstract : 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. READ MORE

7. 5. The diagnostic potential of the He I D3 spectral line in the solar atmosphere

   Author : Tine Libbrecht; Jaime de la Cruz Rodríguez; Jorrit Leenaarts; Göran Scharmer; Valentín Martínez Pillet; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sun; Line formation; Chromosphere; Spectro-Polarimetry; Flares; Reconnection; Astronomy; astronomi;

   Abstract : The research question of my PhD is in a way a simple one: what can observations of the He I D3 line teach us about the solar chromosphere? This optical spectral line at 5876 Å is generally formed in the upper chromosphere, and is sensitive to the local magnetic field. The He I D3 line is also indirectly sensitive to heating of the transition region and corona, since it is resulting from a transition that occurs between levels in the triplet system of neutral helium. READ MORE