Comparison of CME/shock propagation models with heliospheric imaging and in situ observations

TL;DR

This study compares two shock propagation models, DGSTOA and DGSPM, with in situ observations to improve predictions of CME-driven shock arrival times at Earth, demonstrating their effectiveness in space weather forecasting.

Contribution

The paper introduces and validates two data-guided shock propagation models, DGSTOA and DGSPM, for predicting interplanetary shock evolution and arrival times with improved accuracy.

Findings

Shock models predict shock propagation reasonably well after impulsive acceleration.

Predicted shock arrival times and speeds are consistent with WIND measurements.

Drag-Based Model predicts a steeper deceleration than shock models after rapid deceleration.

Abstract

The prediction of the arrival time for fast coronal mass ejections (CMEs) and their associated shocks is highly desirable in space weather studies. In this paper, we use two shock propagation models, i.e. Data Guided Shock Time Of Arrival (DGSTOA) and Data Guided Shock Propagation Model (DGSPM), to predict the kinematical evolution of interplanetary shocks associated with fast CMEs. DGSTOA is based on the similarity theory of shock waves in the solar wind reference frame, and DGSPM on the non-similarity theory in the stationary reference frame. The inputs are the kinematics of the CME front at the maximum speed moment obtained from the geometric triangulation method applied to STEREO imaging observations together with the Harmonic Mean approximation. The outputs provide the subsequent propagation of the associated shock. We apply these models to the CMEs on 2012 January 19, January 23, and March 7. We find that the shock models predict reasonably well the shock's propagation after the impulsive acceleration. The shock's arrival time and local propagation speed at Earth predicted by these models are consistent with in situ measurements of WIND. We also employ the Drag-Based Model (DBM) as a comparison, and find that it predicts a steeper deceleration than the shock models after the rapid deceleration phase. The predictions of DBM at 1 AU agree with the following ICME or sheath structure, not the preceding shock. These results demonstrate the applicability of the shock models used here for future arrival time prediction of interplanetary shocks associated with fast CMEs.