T. Borrmann's research while affiliated with Ruhr-Universität Bochum and other places

Publications (5)

Article
Full-text available
In recent years the variability of the cosmic ray flux has become one of the main issues interpreting cosmogenic elements and especially their connection with climate. In this review, an interdisciplinary team of scientists brings together our knowledge of the evolution and modulation of the cosmic ray flux from its origin in the Milky Way, during...
Article
Full-text available
Two termination shock acceleration modulation models are used to study the modulation of anomalous protons, in particular the effects of different scenarios for global solar wind speed (V) variations in the heliosheath. The first numerical model simulates a symmetric heliosphere and the second simulates an asymmetric heliosphere with respect to the...
Article
Full-text available
A previously used model for the heliospheric modulation of cosmic rays including a solar wind termination shock (TS) is extended to include an asymmetrically shaped outer modulation boundary, with respect to the Sun. The model includes particle drifts, adiabatic energy changes, diffusion, convection, and a heliosheath. It is used to study the effec...
Article
The modelling of the large-scale structure of the heliosphere has made significant progress during recent years. Following hydrodynamic two-fluid approaches taking into account protons and neutral hydrogen, pick-up ions and cosmic rays were included and magnetohydrodynamic models were formulated. The present-day models are, nonetheless, still not c...
Article
The modelling of the large-scale structure of the heliosphere has made significant progress during recent years. Following hydrodynamic two-fluid approaches taking into account protons and neutral hydrogen, pick-up ions and cosmic rays were in- cluded and magnetohydrodynamic models were formulated. The present-day models are, nonetheless, still not...

Citations

... If ( · V) > 0, adiabatic energy losses are described, which become quite large in the inner heliosphere (see the comprehensive review by Fisk, 1979). If ( · V) < 0, energy gains are described, which may be the case for ACRs in the heliosheath (illustrated, e.g., by Langner et al., 2006b; Strauss et al., 2010b). If ( · V) = 0, no adiabatic energy changes occur for CRs, perhaps the case beyond the TS. ...
... Strauss et al. (2010b) developed a numerical model for the acceleration and propagation of anomalous Oxygen in the heliosheath. Apart from diffusive shock acceleration at the termination shock (TS), their model also included momentum diffusion and adiabatic energy changes in the heliosheath (see also Langner et al. 2006;Ferreira et al. 2007). The TS compression ratio and particle injection efficiency were obtained from appropriate hydrodynamic models (Scherer et al. 2006). ...
... Specifically, the atmospheric ionization may alter the physical and chemical properties of the atmosphere and affect several processes, such as aerosol and cloud formation, atmospheric transparency, cloud cover, cyclogenesis and precipitation, especially in regions of middle and high geographic latitudes. Therefore, several numerical models were created and validated via comparison with direct observations and measurements of the CRII, e.g., the Sofia model [8,9], the Bern model, also called ATMOCOSMIC [10,11] and the Oulu model, also called CRAC:CRII [12,13]. Results from the latter model [14] are used in this work. ...