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arXiv · 2403.06614

The influence of different coronal hole geometries on simulations of coronal wave -- coronal hole interaction

I. Piantschitsch·J. Terradas·E. Soubrie·S. G. Heinemann·S. J. Hofmeister·R. Soler·M. Temmer
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Abstract

The geometry of a coronal hole (CH) affects the density profile of the reflected part of an incoming global coronal wave (CW). In this study, we perform for the first time magnetohydrodynamic (MHD) simulations of fast-mode MHD waves interacting with CHs of different geometries, such as circular, elliptic, convex, and concave shapes. We analyse the influence these geometries have on the density profiles of the reflected waves and we generate the corresponding simulation-based time-distance plots. Within these time-distance plots we determine regions that exhibit specific density features, such as large reflected density amplitudes. In a further step, these interaction features can be compared to actual observed CW-CH interaction events which makes it possible to explain interaction parameters from the observed interaction events, such as the density structure of the reflected wave, which are usually difficult to comprehensively understand by only analysing the measurements. Moreover, we show that the interaction between a concave shaped CH and CWs, whose density profile include an enhanced as well as a depleted wave, can lead to reflected density amplitudes that are more than two times larger than the incoming ones. Another effect of the interplay between the constructive and destructive interference of the reflected wave parts is a strongly depleted region in the middle of the CW-CH interaction process. In addition, we show how important the choice of the path is that is used to generate the time-distance plots and how this choice affects the interpretation of the CW-CH interaction results.

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I. Piantschitsch, J. Terradas, E. Soubrie, S. G. Heinemann, S. J. Hofmeister, R. Soler, M. Temmer. 2024-03-11. The influence of different coronal hole geometries on simulations of coronal wave -- coronal hole interaction. https://arxiv.org/abs/2403.06614

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