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Ioannis Kontogiannis (AIP)

Magnetic polarity inversion lines properties and CME characteristics
When Oct 25, 2018 from 02:30 PM to 03:30 PM
  • Colloquium
Where SH Lecture Hall
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Coronal mass ejections (CMEs) are the most dramatic events in the solar system, injecting tremendous amounts of mass into the interplanetary space. They are often associated with major flares, i.e. abrupt, localized brightenings of the solar atmosphere, observed throughout the electromagnetic spectrum. Both flares and CMEs are the main drivers of space weather, causing adverse effects in space technologies and ground-based infrastructures. Both phenomena are powered by the immense amounts of magnetic energy stored in the complex magnetic fields of active regions of the Sun. A common topological feature of highly complex and, thus, flare productive active regions is the presence of intense magnetic polarity inversions lines, which signify neighboring, interacting, opposite magnetic polarities. An overview of parameters that quantify the importance of magnetic polarity inversion lines will be presented, along with recently developed, promising ones. These parameters are derived from observations of the photospheric magnetic fields of active regions and are being routinely used in flare and CME prediction services. The relevance of these parameters in respect with flare strength and CME importance will also be examined. Each of these MPIL-associated parameters contains different information and is subject to different instrumental effects, leading to a different degree of correlation with eruption characteristics. It is concluded that the highest correlation is exhibited by two of these parameters, namely the length of the main MPIL and the net (non-neutralized) current injected into the solar corona, which are related through an explicit cause-end-effect relationship.