![]() It is plausible that the magnetic field structure in the QS photosphere is in the form of a “salt-pepper” pattern with poles of upwardand downward-oriented fields. The results confirms that both the tiny current sheets related to nanoflares and the hierarchy of largescale current sheets are plausible mechanisms for coronal heating. Five theoretical models with different magnetic field configurations are evolved over time intervals of 30-80 min of solar time, and the resulting coronal temperatures and amounts of Joule heating (ohmic heating) in each model are analyzed, compared to each other and compared to the corresponding results of a standard model evolved by Hansteen et al. To analyze the problem, the numerical code Bifrost is applied to solve the MHD equations on three-dimensional cutouts of the quiet-Sun (QS) atmosphere. Both mechanisms are actively referred to in the later chapters of this thesis. Two plausible heating mechanisms are discussed, both related to the generation of current sheets: 1) the stressing of a magnetic field which collapses into tiny current sheets (width of order 10 m) which eventually burst out as a nanoflare, a mechanism introduced by Parker (1988), and 2) a hierarchy of current sheets, analyzed by Galsgaard & Nordlund (1996), which also includes large-scale current sheets (width of several megameters) not related to nanoflares. Finally, the corona is brought into discussion, which leads us to the coronal heating problem. The question is: how does the coronal heating depend on the photospheric magnetic fields? That is the problem which this thesis focuses on.īefore investigating the problem, an introduction to the Sun is given, reviewing everything from the basics of a general star to the structure of the entire Sun, going through each layer, with focus on the atmosphere. As of today, most solar physicists agree that the mechanism that heats the corona is connected to the dynamics of the magnetic fields in the photosphere. This fact has puzzled solar physicists for more than six decades. Who knows? We may even develop technology that will allow us to venture even closer to our very own star.AbstractThe solar corona has a temperature of order 1 MK, which is almost 200 times the temperature of the underlying surface. Something that was unimaginable has been achieved. Parker solar probe's achievement has been a result of decades of patient research and resolute, steady scientific progress towards the goal. NASA publicly declared its ambition of sending a probe to the Sun in the 50s. Mankind had dreamed of knowing more about the Sun for millennia at least. Parker probe's achievements has been nothing short of a 'dream come true' in words of NASA scientists quoted by the agency in its reports. At this time, the probe was 8 million kms away from solar surface.Īs the probe entered corona, it also found that magnetic field of the Sun grew much stronger. Outside Corona, the material was more readily sent out. The instruments of the probe found that as the craft entered Corona, there was marked difference in the extent to which solar material was projected out in space. Outside Corona they are ejected as Solar Wind. ![]() (Solar particles inside corona (left) are more bound to the Sun. What did Parker solar probe find inside solar atmosphere? During its 8th revolution around the Sun in April 2021, Parker solar probe entered the Corona The probe went around the Sun several times, the orbit reducing each time. NASA launched Parker solar probe in August 2018. Understanding solar atmosphere may make us protect our spacecrafts and satellites better. It originates from Sun's atmosphere (the Corona). We do not fully know why solar wind is sent out at very high speeds from Sun. Earth's atmosphere and magnetic field shields all life on the surface but same isn't always true about satellites revolving around Earth. ![]() It is capable of making million-dollar satellites a piece of junk. Solar material is constantly ejected from the Sun at extremely high speeds. ![]() As much as it supports life on Earth, Sun in unforgiving to anything that is in its vicinity without proper protection.
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