Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions: Global kinetic simulations and Soft X-ray Imaging

Abstract

The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a joint mission of the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS). Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind (SW) impact via simultaneous in situ magnetosheath plasma and magnetic field measurements, X-Ray images of the magnetosheath and magnetic cusps, and UV images of global auroral distributions. Magnetopause deformations associated with magnetosheath high speed jets (HSJs) under a quasi-parallel interplanetary magnetic field condition are studied using a three-dimensional (3-D) global hybrid simulation. Soft X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is compared. We obtain key findings concerning deformations at the magnetopause: (1) Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock, (2) X-ray intensities estimated using solar wind \begin{document}${\rm{H}}^+$\end{document} and self-consistent \begin{document}${\rm{O}}^{7+}$\end{document} ions are consistent with each other, (3) Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits, respectively. The SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane. A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients, such as HSJs, at medium altitudes on its orbit. Simulation results also demonstrate that a lunar based imager (e.g., Lunar Environment heliospheric X-ray Imager, LEXI) is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian plane. These preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes.

Keywords

• collisionless shock
• smile mission
• foreshock