Magnetopause Reconnection as Influenced by the Dipole Tilt Under Southward IMF Conditions: Hybrid Simulation and MMS Observation

Abstract

Using a three-dimensional (3-D) global-scale hybrid code, the Magnetospheric Multiscale (MMS) reconnection event around 02:13 UT on 18 November 2015, highlighted in the Geospace Environment Modeling (GEM) Dayside Kinetic Challenge, is simulated, in which the interplanetary magnetic field (IMF) points southward and the geomagnetic field has a −27°dipole tilt angle. Strong southward plasma jets are found near the magnetopause as a result of the dayside reconnection. Our results indicate that the subsolar magnetopause reconnection X line shifts from the subsolar point toward the Northern Hemisphere due to the effect of the tilted geomagnetic dipole angle, consistent with the MMS observation. Subsequently, the reconnection X lines or sites and reconnection flux ropes above the equator propagate northward along the magnetopause. The formation and global distribution of the X lines and the structure of the magnetopause reconnection are investigated in detail with the simulation. Mirror mode waves are also found in the middle of the magnetosheath downstream of the quasi-perpendicular shock where the plasma properties are consistent with the mirror instability condition. As a special outcome of the GEM challenge event, the spatial and temporal variations in reconnection, the electromagnetic power spectra, and the associated D-shaped ion velocity distributions in the simulated reconnection event are compared with the MMS observation.

Investigation of the Interaction Between Magnetosheath Reconnection and Magnetopause Reconnection Driven by Oblique Interplanetary Tangential Discontinuity Using Three‐Dimensional Global Hybrid Simulation

“…As these magnetopause flux ropes move poleward with the magnetosheath flows, new flux ropes are formed near the original location, and the process repeats in time, as discussed in work of Guo et al. (2020). In fact, there are four types of flux ropes in the magnetopause reconnection.…”

Global Hybrid Simulations of Interaction Between Interplanetary Rotational Discontinuity and Bow Shock/Magnetosphere: Can Ion‐Scale Magnetic Reconnection be Driven by Rotational Discontinuity Downstream of Quasi‐Parallel Shock?

“…In Figure 7e, the presence of outflow reconnection jets with V iz of opposite signs can be seen on the two sides of the “ X ” point, pointing away from the “ X ” point. At this moment, the “ X ” point moves northward with the ambient magnetosheath flow (e.g., Guo, Lin, Wang, Vines, et al., 2020), with a speed of ∼1.0 V A 0 . The outflow velocity northward of the “ X ” point is northward, ∼1.7 V A 0 , larger than the speed of the “ X ” point.…”

Magnetohydrodynamic With Embedded Particle‐In‐Cell Simulation of the Geospace Environment Modeling Dayside Kinetic Processes Challenge Event

“…Figure 3 shows the magnetopause crossing magnetic fields from the MMS3 spacecraft, the Auburn Hybrid model (Guo et al, 2020), and the SWMF ideal‐MHD, Hall‐MHD, and MHD‐EPIC simulations. The Auburn hybrid model is another model that simulated the GEM dayside kinetic processes challenge event.…”

“…The Auburn hybrid model is another model that simulated the GEM dayside kinetic processes challenge event. We plot the hybrid simulation results here for completeness, and more details about the hybrid simulation can be found in Guo et al (2020). We focus on the comparison between the MMS3 data and the SWMF simulations in the present paper.…”

“…Figure 4 shows the power spectral densities (PSDs) of the perpendicular and parallel magnetic field fluctuations in the magnetosheath, the current sheet, and the magnetosphere. The details of calculating the PSDs from the MMS3 data can be found in Guo et al (2020). In the simulations, we use the magnetic field data collected at , , and along the MMS3 orbit to represent the magnetosheath, current sheet, and magnetosphere, respectively.…”