EGU21-8932
https://doi.org/10.5194/egusphere-egu21-8932
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effect of the ambient solar wind speed on drag-based CME prediction accuracy

Tanja Amerstorfer1, Jürgen Hinterreiter1,2, Martin A. Reiss1, Jackie A. Davies3, Christian Möstl1, Andreas J. Weiss1,2, Maike Bauer1,2, Ute V. Amerstorfer1, Rachel L. Bailey1, and Richard A. Harrison1
Tanja Amerstorfer et al.
  • 1Space Research Institute, Austrian Academy of Sciences, Graz, Austria (tanja.amerstorfer@oeaw.ac.at)
  • 2Institute of Physics, University of Graz, Graz, Austria
  • 3RAL Space, Rutherford Appleton Laboratory, Harwell Campus, UK

In the last years, many kinds of CME models, based on a drag-based evolution through interplanetary space, have been developed and are now widely used by the community. The unbeatable advantage of those methods is that they are computationally cheap and are therefore suitable to be used as ensemble models. Additionally, their prediction accuracy is absolutely comparable to more sophisticated models.

The ELlipse Evolution model based on heliospheric imager (HI) observations (ELEvoHI) assumes an elliptic frontal shape within the ecliptic plane and allows the CME to adjust to the ambient solar wind speed, i.e. it is drag-based. ELEvoHI is used as an ensemble simulation by varying the CME frontal shape within given boundary values. The results include a frequency distribution of predicted arrival time and arrival speed and an estimation of the arrival probability.

In this study, we investigate the possibility of not only varying the parameters related to the CME's ecliptic extent but also the ambient solar wind speed for each CME ensemle member. Although we have used a range of +/-100 km/s for possible values of the solar wind speed in the past, only the best candidate was in the end used to contribute to the prediction. We present the results of this approach by applying it to a CME propagating in a highly structured solar wind and compare the frequency distribution of the arrival time and speed predictions to those of the usual ELEvoHI approach.

How to cite: Amerstorfer, T., Hinterreiter, J., Reiss, M. A., Davies, J. A., Möstl, C., Weiss, A. J., Bauer, M., Amerstorfer, U. V., Bailey, R. L., and Harrison, R. A.: Effect of the ambient solar wind speed on drag-based CME prediction accuracy, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8932, https://doi.org/10.5194/egusphere-egu21-8932, 2021.

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