Work

Interplanetary Magnetic Field B y Controlled Alfvén Wings at Earth During an Encounter of a Coronal Mass Ejection

Year: 2025

Type: article

Abstract: On 24 April 2023, an ICME reached Earth's orbit. The solar wind density dropped to 0.3 amu/cc while the IMF strength was about 25 nT. As a result, the solar wind flow transitions to a sub‐Alfvénic state with an Alfvén Mach number of 0.4. We carry out global magnetohydrodynamic simulations to investigate the responses of Earth's magnetosphere to the ICME ejecta. The results show the formation of Alfvén wings as the solar wind becomes sub‐Alfvénic. Furthermore, the sub‐Alfvénic period was characterized by the dominance of the IMF component, causing the Alfvén wings to extend toward the dawn and dusk flanks. We investigate the global magnetospheric convection of this sub‐ Alfvénic case and find that the overall convection is mediated by the Alfvén wings, while the magnetic field convection in inner magnetosphere is similar to the super‐Alfvénic case.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl113416

Authors: Yuxi Chen, Chuanfei Dong, Li‐Jen Chen, Menelaos Sarantos, Brandon L. Burkholder

Institutions: Boston University, University of Michigan, Goddard Space Flight Center

Language: English

Topic: Ionosphere and magnetosphere dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,190

Funders: National Aeronautics and Space Administration, Heliophysics Division