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| Titel |
Cosmic Rays in Thunderstorms |
| VerfasserIn |
Stijn Buitink, Olaf Scholten, Ad van den Berg, Ute Ebert |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083683
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| Zusammenfassung |
| Cosmic Rays in Thunderstorms
Cosmic rays are protons and heavier nuclei that constantly bombard the Earth’s
atmosphere with energies spanning a vast range from 109 to 1021 eV. At typical altitudes
up to 10-20 km they initiate large particle cascades, called extensive air showers,
that contain millions to billions of secondary particles depending on their initial
energy. These particles include electrons, positrons, hadrons and muons, and are
concentrated in a compact particle front that propagates at relativistic speed. In addition,
the shower leaves behind a trail of lower energy electrons from ionization of air
molecules.
Under thunderstorm conditions these electrons contribute to the electrical and ionization
processes in the cloud. When the local electric field is strong enough the secondary electrons
can create relativistic electron run-away avalanches [1] or even non-relativistic avalanches.
Cosmic rays could even trigger lightning inception. Conversely, strong electric fields also
influence the development of the air shower [2].
Extensive air showers emit a short (tens of nanoseconds) radio pulse due to deflection of the
shower particles in the Earth’s magnetic field [3]. Antenna arrays, such as AERA, LOFAR
and LOPES detect these pulses in a frequency window of roughly 10-100 MHz. These
systems are also sensitive to the radiation from discharges associated to thunderstorms, and
provide a means to study the interaction of cosmic ray air showers and the electrical
processes in thunderstorms [4].
In this presentation we discuss the involved radiation mechanisms and present analyses of
thunderstorm data from air shower arrays
[1] A. Gurevich et al., Phys. Lett. A 165, 463 (1992)
[2] S. Buitink et al., Astropart. Phys. 33, 1 (2010)
[3] H. Falcke et al., Nature 435, 313 (2005)
[4] S. Buitink et al., Astron. & Astrophys. 467, 385 (2007) |
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