Berlin 2014 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 8: Sonne und Heliosphäre (II)

EP 8.5: Vortrag

Freitag, 21. März 2014, 11:45–12:00, DO24 1.103

Influence of Ground Level Enhancements on the Terrestrial Production of ¹⁰Be, ¹⁴C and ³⁶Cl — •Konstantin Herbst¹, Jürg Beer², Bernd Heber¹, Allan J. Tylka³, and William F. Dietrich⁴ — ¹IEAP, Christian-Albrechts-Universität zu Kiel, Kiel, Germany — ²Swiss Federal Institute of Aquatic Science and Technology, EAWAG, Switzerland — ³Space Science Division, Naval Research Laboratory, Washington, DC, USA — ⁴Praxis, Inc., Alexandria, VA, USA

Cosmogenic radionuclides are a product of the interaction of primary cosmic rays, in particular galactic cosmic rays (GCRs), with the Earth’s atmosphere. But only primary particles with energies above several 100 MeV can trigger the necessary reaction chains. Because GCRs are modulated by the solar activity on their way through the interplanetary medium the GCR-induced cosmogenic radionuclide production is anti-correlated to the solar cycle. During phases of strong solar activity also solar energetic particle (SEP) events occur frequently. In particular SEP events which can be detected by ground-based instruments, so-called ground level enhancements (GLEs), may strongly contribute to the cosmogenic radionuclide production. Beside the variation due to the modulation of GCRs we will investigate the influence of 58 GLEs, which occurred within the past five solar cycles and discuss the possibility to detect such events in present ice-core and tree-ring records. In addition, an estimate for the probability to find such events over the past 10’000 years, also known as Holocene, during different modulation conditions will be given.