PT Unknown AU Herbst, K TI Interaction of Cosmic Rays with the Earth's Magnetosphere and Atmosphere - Modeling the Cosmic Ray Induced Ionization and the Production of Cosmogenic Radionuclides PY 2013 PU Christian-Albrechts-Universität zu Kiel WP https://macau.uni-kiel.de/receive/diss_mods_00010634 LA en DE Cosmic Rays; Ionization; Cosmogenic Radionuclides; Kosmische Strahlung; Ionisation; Kosmogene Radionuklide AB Cosmogenic radionuclides like $^{10}$Be and $^{14}$C are produced by reactions of primary cosmic rays (CR) and secondary particles with atmospheric nuclei, are then mixed in the atmosphere and finally deposited in natural archives like ice sheets, tree rings or sediments. Because the flux of CRs strongly depends on solar activity the production rate of cosmogenic radionuclides being stored in these archives have recorded the solar activity over thousands of years. Although cosmogenic radionuclide measurements can, thus, in principle be used to reconstruct solar activity back in time, the problem arises that reconstructions based on $^{10}$Be and $^{14}$C differ significantly. This work provides a reconstruction which for the first time is consistent with both $^{10}$Be and $^{14}$C archive data. In order to do so, the full simulation chain --- starting with the local interstellar medium beyond the heliosphere and ending with the deposition of the radionuclides in natural archives --- determining the generation of cosmogenic radionuclides has to be taken into account. For the reconstruction of the solar activity over thousands of years in this work the activity is reflected by the solar modulation parameter $\phi$. Investigating first the different local interstellar spectrum (LIS) models this work provides a method to convert them into each other, models the CR modulation within the heliosphere and studies their consistency with terrestrial and space data. Secondly, the particle transport within the Earth's magnetosphere is described, stressing the importance of the field geometry for the vertical cutoff rigidity, complemented by investigations of the direction of incidence. In a third step the secondary particle environment and its dependence on the respective LIS model as well as hadronic interaction models is studied. Using LIS-dependent solar modulation parameters all LIS models are shown to be able to represent the measurements. In order to decide which hadronic interaction model is the more suitable one, fourth, the CR-induced ionization of the atmosphere is investigated, favoring the Bertini model rather than the BIC model. After having successfully validated the local and global production rates of $^{10}$Be, $^{7}$Be, $^{36}$Cl, $^{3}$H, $^{26}$Al and $^{14}$C in a fifth issue, on the basis of modeled and measured production rates and taking into account temporal variations of the Earth's magnetic field strengths, this work provides a new solar modulation parameter being able to represent $^{10}$Be as well as $^{14}$C data over the entire Holocene. PI Kiel ER