Abstract
AbstractOur previous hybrid simulation (Shi et al., 2013) under a radial interplanetary magnetic field (IMF) and a supercritical solar wind Mach number has shown that foreshock compressional waves originated from the quasi‐parallel (Q‐∥) shock are mode converted to kinetic Alfvén waves (KAWs) at the Alfvén resonance surface of the subsolar magnetopause. In this paper, three‐dimensional global dayside mode conversion is investigated for cases under various solar wind conditions using the global hybrid model. The global patterns and propagations of KAWs are distinguished and presented. Under a near‐critical Mach number (MA=3), KAW structures due to mode conversion exhibit a feature of broader excitation regions in the magnetopause boundary layer (MPBL) compared to supercritical Mach number (MA=5) shocks. For cases with an oblique IMF with supercritical Mach numbers (MA=5), the amplitude of magnetosheath compressional waves is larger at the quasi‐parallel shock (Q‐∥) than at the quasi‐perpendicular (Q‐⊥) shock. Downstream of the Q‐∥ shock, there is a general trend that the perturbations of density (N) and magnetic field (B) change from predominantly in‐phase in the magnetosheath to antiphase near the MPBL. While downstream of the Q‐⊥ shock, an antiphase relation between N and B is dominant throughout the magnetosheath and magnetopause except near the shock transition. The compressional drivers are found to reach an extended region of the magnetopause due to the combined effects of wave propagation in the plasma frame and flow convection, leading to a broad region of mode conversion at the magnetopause. Subsequently, the resulting KAWs can be carried to the regions downstream of the Q‐⊥ shock owing to the flow convection at the magnetopause. The KAWs propagate poleward along the geomagnetic field lines and meanwhile are carried tailward by the ambient flows, and they are more intense in the downstream of Q‐∥ shocks than downstream of Q‐⊥ shocks.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
