Dawn‐dusk asymmetry in solar wind ion entry and dayside precipitation: Results from large‐scale simulations

摘要: We present the results of numerical studies interaction solar wind ions with dayside magnetospheric boundary for a southward interplanetary magnetic field and two speeds (250 500 km/s) using global magnetohydrodynamics simulations in conjunction large-scale kinetic calculations. Results these show that dawn-dusk asymmetry is found precipitation low- to middle-energy over high-latitude magnetosphere. This consistent statistical DMSP data showing ion from mantle predominantly seen morning prenoon sector. Analysis energy-latitude spectra study individual particle trajectories revealed low-energy can enter magnetopause at high latitudes regions where parallel electric associated current positive strong enough gain energies order potential drop across magnetopause. Because Northern Hemisphere sector negative afternoon-evening sector, reaching are accelerated toward ionosphere on dawnside outward duskside, creating precipitation. The same Southern because both reversed direction.