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Quantifying the uncertainty in CME kinematics derived from geometric modelling of Heliospheric Imager data
  • +7
  • Luke Barnard,
  • Mathew J Owens,
  • Christopher John Scott,
  • Michael Lockwood,
  • Curt A. de Koning,
  • Tanja Amerstorfer,
  • Juergen Hinterreiter,
  • Christian Moestl,
  • Jackie A Davies,
  • Pete Riley
Luke Barnard
University of Reading

Corresponding Author:[email protected]

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Mathew J Owens
University of Reading
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Christopher John Scott
University of Reading
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Michael Lockwood
University of Reading
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Curt A. de Koning
National Oceanic and Atmospheric Administration (NOAA)
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Tanja Amerstorfer
Space Research Institute, Austrian Academy of Sciences
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Juergen Hinterreiter
Space Research Institute, Austrian Academy of Sciences
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Christian Moestl
Austrian Academy of Sciences
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Jackie A Davies
Rutherford Appleton Laboratory
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Pete Riley
Predictive Science Inc.
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Abstract

Geometric modelling of Coronal Mass Ejections (CMEs) is a widely used tool for assessing their kinematic evolution. Furthermore, techniques based on geometric modelling, such as ELEvoHI, are being developed into forecast tools for space weather prediction. These models assume that solar wind structure does not affect the evolution of the CME, which is an unquantified source of uncertainty.
We use a large number of Cone CME simulations with the HUXt solar wind model to quantify the scale of uncertainty introduced into geometric modelling and the ELEvoHI CME arrival times by solar wind structure. We produce a database of simulations, representing an average, a fast, and an extreme CME scenario, each independently propagating through 100 different ambient solar wind environments. Synthetic heliospheric imager observations of these simulations are then used with a range of geometric models to estimate the CME kinematics. The errors of geometric modelling depend on the location of the observer, but do not seem to depend on the CME scenario. In general, geometric models are biased towards predicting CME apex distances that are larger than the true value. For these CME scenarios, geometric modelling errors are minimised for an observer in the L5 region. Furthermore, geometric modelling errors increase with the level of solar wind structure in the path of the CME. The ELEvoHI arrival time errors are minimised for an observer in the L5 region, with mean absolute arrival time errors of 8.2±1.2h, 8.3±1.0h, and 5.8±0.9h for the average, fast, and extreme CME scenarios
Jan 2022Published in Space Weather volume 20 issue 1. 10.1029/2021SW002841