Drag-based CME modeling with heliospheric images incorporating frontal
deformation: ELEvoHI 2.0
Abstract
The evolution and propagation of coronal mass ejections (CMEs) in
interplanetary space is still not well understood. As a consequence,
accurate arrival time and arrival speed forecasts are an unsolved
problem in space weather research. In this study, we present the ELlipse
Evolution model based on HI observations (ELEvoHI) and introduce a
deformable front to this model. ELEvoHI relies on heliospheric imagers
(HI) observations to obtain the kinematics of a CME. With the newly
developed deformable front, the model is able to react to the ambient
solar wind conditions during the entire propagation and along the whole
front of the CME. To get an estimate of the ambient solar wind
conditions, we make use of three different models: Heliospheric Upwind
eXtrapolation model (HUX), Heliospheric Upwind eXtrapolation with time
dependence model (HUXt), and EUropean Heliospheric FORecasting
Information Asset (EUHFORIA). We test the deformable front on a CME
first observed in STEREO-A/HI on February 3, 2010 14:49 UT. For this
case study, the deformable front provides better estimates of the
arrival time and arrival speed than the original version of ELEvoHI
using an elliptical front. The new implementation enables us to study
the parameters influencing the propagation of the CME not only for the
apex, but for the entire front. The evolution of the CME front,
especially at the flanks, is highly dependent on the ambient solar wind
model used. An additional advantage of the new implementation is given
by the possibility to provide estimates of the CME mass.