Modeling a Coronal Mass Ejection as a Magnetized Structure with EUHFORIA

G Sindhuja,B Raghavendra Prasad,E Asvestari,Jagdev Singh

doi:10.3847/1538-4357/ac3bd2

G Sindhuja, B Raghavendra Prasad + Show 2 more

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https://doi.org/10.3847/1538-4357/ac3bd2

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Abstract

Abstract We studied an Earth-directed coronal mass ejection (CME) that erupted on 2015 March 15. Our aim was to model the CME flux rope as a magnetized structure using the European Heliospheric Forecasting Information Asset (EUHFORIA). The flux rope from eruption data (FRED) output was applied to the EUHFORIA spheromak CME model. In addition to the geometrical properties of the CME flux rope, we needed to input the parameters that determine the CME internal magnetic field like the helicity, tilt angle, and toroidal flux of the CME flux rope. According to the FRED technique geometrical properties of the CME flux rope are obtained by applying a graduated cylindrical shell fitting of the CME flux rope on the coronagraph images. The poloidal field magnetic properties can be estimated from the reconnection flux in the source region utilizing the post-eruption arcade method, which uses the Heliospheric Magnetic Imager magnetogram together with the Atmospheric Imaging Assembly (AIA) 193 Å images. We set up two EUHFORIA runs with RUN-1 using the toroidal flux obtained from the FRED technique and RUN-2 using the toroidal flux that was measured from the core dimming regions identified from the AIA 211 Å images. We found that the EUHFORIA simulation outputs from RUN-1 and RUN-2 are comparable to each other. Overall using the EUHFORIA spheromak model, we successfully obtained the magnetic field rotation of the flux rope, while the arrival time near Earth and the strength of the interplanetary CME magnetic field at Earth are not as accurately modeled.

Highlights

Coronal mass ejections (CMEs) are primary sources of geomagnetic storms and can have a great impact on the nearEarth environment and our society
The inputs required for EUHFORIA that are obtained from the GCS fitting of the CME flux rope are the location parameter of the source region, the CME speed, the time at which the CME reaches 0.1 au, the halfangle, the aspect ratio, and the tilt angle
In order for the magnetic field topology of the spheromak at the inner boundary of the modeling domain to better agree with that observed by LOS magnetic field measurements the tilt of the spheromak is taken to be equal to the tilt of the GCS rotated counterclockwise by 90°, similar to what was considered for the CME event studied with EUHFORIA in Asvestari et al (2021b)

Summary

Introduction

Coronal mass ejections (CMEs) are primary sources of geomagnetic storms and can have a great impact on the nearEarth environment and our society. Forecasting CME properties, such as arrival time and magnetic field strength and orientation, is of great importance. The semiempirical Wang–Sheeley–Arge model is a combination of the PFSS, the SCS, and a semiempirical velocity extension (Arge & Pizzo 2000), which forms the most commonly used coronal model that extends up to 0.1 au. This model can be coupled with magnetohydrodynamic (MHD) models that focus on the propagation of the solar wind up to 1–2 au in what is called a heliospheric model

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