Large‐Scale Magnetosheath Jets Formed by Shock‐Discontinuity Interactions: A Three‐Dimensional Global Hybrid Simulation

Abstract Magnetosheath high‐speed jets with enhanced dynamic pressure are common in Earth's magnetosheath and can impinge on the magnetopause, driving pronounced boundary deformation. Recent observations indicate that shock–discontinuity interactions (SDIs) can generate magnetosheath jets, but the formation mechanism is still unclear. Using a three‐dimensional global hybrid simulation, we investigate SDI‐driven magnetosheath jets. SDI‐driven deformation of the bow shock redirects the solar wind according to the Rankine–Hugoniot relations—deflecting the flow along the shock with little deceleration—thereby producing ribbon‐like jets flanking the core of a hot flow anomaly. The jets span the entire dayside magnetosheath and reach ∼40 Earth radii () along the discontinuity downstream of both quasi‐parallel and quasi‐perpendicular shocks. The SDI‐driven structures produce a magnetopause distortion that attains an amplitude of ∼5 and extends ∼17 along the discontinuity, propagating from the dayside to the nightside. Synthetic soft X‐ray images derived from the simulation indicate that SDI‐driven structures should be detectable by forthcoming global soft X‐ray missions.