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| Titel |
SOHO/EPHIN energy spectra during GLE 69 and 70 |
| VerfasserIn |
Bernd Heber, Patrick Kühl, Nina Dresing, Andreas Klassen |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125332
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| Publikation (Nr.) |
 EGU/EGU2016-4902.pdf |
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| Zusammenfassung |
| Ground Level Enhancements (GLEs) are solar energetic particle (SEP) events that are
recorded by ground-based instrumentation. The energy of the particles is so high that they
produce secondary particles in the Earth’s atmosphere, i.e. protons and neutrons,
which are detected as sudden increases in cosmic ray intensities measured by e.g.
neutron monitors. Since the launch of SOHO in December 1995 the neutron monitor
network recorded 16 GLEs. The Electron Proton Helium INstrument on board SOHO
has been designed to measure protons and helium up to 53 MeV/nucleon as well
as electrons up to 8.3 MeV. Above these energies, particles penetrate all detector
elements and thus, a separation between different particle species becomes more
complicated. Recently we developed a method that allows deriving the energy spectrum for
penetrating protons up to more than 1 GeV. In this contribution we present the
proton energy spectra for two of the 16 above-mentioned GLEs and compare them to
previous measurements. Although there are differences of up to a factor two the overall
shape of the energy spectra agree surprisingly well. Thus it has been demonstrated
that EPHIN measurements are a valuable tool for understanding GLE. In addition
our measurements allow the investigation of SUB GLEs that are events that are
below the threshold of GLEs but may affect the ionization in the upper atmosphere. |
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