Predicting CME Arrivals with Heliospheric Imagers from L5: A Data Assimilation Approach

TL;DR

This study evaluates how incorporating heliospheric imager data from L5 improves CME arrival predictions, highlighting the benefits, challenges, and potential for operational space weather forecasting, especially for upcoming missions.

Contribution

It demonstrates the impact of real-time HI data integration from L5 on CME prediction accuracy and assesses human tracking variability and different propagation direction methods.

Findings

HI data beyond 35° elongation improves predictions

Manual tracking variability affects forecast accuracy

HI-based direction estimates have trade-offs with coronagraph methods

Abstract

The Solar TErrestrial RElations Observatory (STEREO) mission has laid a foundation for advancing real-time space weather forecasting by enabling the evaluation of heliospheric imager (HI) data for predicting coronal mass ejection (CME) arrivals at Earth. This study employs the ELEvoHI model to assess how incorporating STEREO/HI data from the Lagrange 5 (L5) perspective can enhance prediction accuracy for CME arrival times and speeds. Our investigation, preparing for the upcoming ESA Vigil mission, explores whether the progressive incorporation of HI data in real-time enhances forecasting accuracy. The role of human tracking variability is evaluated by comparing predictions based on observations by three different scientists, highlighting the influence of manual biases on forecasting outcomes. Furthermore, the study examines the efficacy of deriving CME propagation directions using HI-specific methods versus coronagraph-based techniques, emphasising the trade-offs in prediction accuracy. Our results demonstrate the potential of HI data to significantly improve operational space weather forecasting when integrated with other observational platforms, especially when HI data from beyond 35{\deg} elongation are used. These findings pave the way for optimising real-time prediction methodologies, providing valuable groundwork for the forthcoming Vigil mission and enhancing preparedness for CME-driven space weather events.