Using Solar Orbiter as an upstream solar wind monitor for real time space weather predictions

TL;DR

This study demonstrates that Solar Orbiter can effectively serve as an upstream monitor for real-time space weather prediction, significantly improving CME arrival time forecasts and magnetic field structure predictions using real-time measurements and ensemble modeling.

Contribution

The paper presents a novel approach to use Solar Orbiter's real-time magnetic field data at 0.5 AU to enhance CME arrival time and magnetic structure predictions for space weather forecasting.

Findings

Reduced CME arrival time uncertainty from 10.4 to 2.5 hours.

Excellent magnetic field profile agreement between Solar Orbiter and Wind.

Potential for predicting CME sub-structure over a day in advance.

Abstract

Coronal mass ejections (CMEs) can create significant disruption to human activities and systems on Earth, much of which can be mitigated with prior warning of the upstream solar wind conditions. However, it is currently extremely challenging to accurately predict the arrival time and internal structure of a CME from coronagraph images alone. In this study, we take advantage of a rare opportunity to use Solar Orbiter, at 0.5\,AU upstream of Earth, as an upstream solar wind monitor. We were able to use real time science quality magnetic field measurements, taken only 12 minutes earlier, to predict the arrival time of a CME prior to reaching Earth. We used measurements at Solar Orbiter to constrain an ensemble of simulation runs from the ELEvoHI model, reducing the uncertainty in arrival time from 10.4\,hours to 2.5\,hours. There was also an excellent agreement in the $B_z$ profile between Solar Orbiter and Wind spacecraft, despite being separated by 0.5\,AU and 10$^{\circ}$ longitude. Therefore, we show that it is possible to predict not only the arrival time of a CME, but the sub-structure of the magnetic field within it, over a day in advance. The opportunity to use Solar Orbiter as an upstream solar wind monitor will repeat once a year, which should further help assess the efficacy upstream in-situ measurements in real time space weather forecasting.