Variations of Pressure Profiles from the Bow Shock to Magnetopause

Numerous simulation results have shown that the spatial profiles of a thermal pressure from the bow shock to the magnetopause are determined by the upstream interplanetary magnetic field (IMF) orientation. The southward IMF conditions lead to an increasing trend of thermal pressure with a maximum near the magnetopause. In contrast, the thermal pressure increases on the plasma entry to the  magnetosheath, but this trend turns to a decreasing one after passing a middle point between the bow shock and magnetopause during northward IMF intervals. In the present study, we show the observation results, both particular events and statistics, to check the variations of pressure profiles in the magnetosheath and their relation to upstream IMF conditions. THEMIS-C observartions during 2007–2009 are used. The profiles near the Sun–Earth line and the global pressure distribution in the dayside equatorial magnetosheath are shown.