Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 27, 989-1004, 2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
02 Mar 2009
A novel code for numerical 3-D MHD studies of CME expansion
J. Kleimann1, A. Kopp2,3, H. Fichtner3, and R. Grauer4 1Nordlys Observatoriet, Universitetet i Tromsø, 9037 Tromsø, Norway
2Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany
3Institut für Theoretische Physik IV, Ruhr-Universität Bochum, 44780 Bochum, Germany
4Institut für Theoretische Physik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
Abstract. A recent third-order, essentially non-oscillatory central scheme to advance the equations of single-fluid magnetohydrodynamics (MHD) in time has been implemented into a new numerical code. This code operates on a 3-D Cartesian, non-staggered grid, and is able to handle shock-like gradients without producing spurious oscillations.

To demonstrate the suitability of our code for the simulation of coronal mass ejections (CMEs) and similar heliospheric transients, we present selected results from test cases and perform studies of the solar wind expansion during phases of minimum solar activity. We can demonstrate convergence of the system into a stable Parker-like steady state for both hydrodynamic and MHD winds. The model is subsequently applied to expansion studies of CME-like plasma bubbles, and their evolution is monitored until a stationary state similar to the initial one is achieved. In spite of the model's (current) simplicity, we can confirm the CME's nearly self-similar evolution close to the Sun, thus highlighting the importance of detailed modelling especially at small heliospheric radii.

Additionally, alternative methods to implement boundary conditions at the coronal base, as well as strategies to ensure a solenoidal magnetic field, are discussed and evaluated.

Citation: Kleimann, J., Kopp, A., Fichtner, H., and Grauer, R.: A novel code for numerical 3-D MHD studies of CME expansion, Ann. Geophys., 27, 989-1004, doi:10.5194/angeo-27-989-2009, 2009.
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