Plasma Pressure under Magnetopause on the Dusk Flank in the Equatorial Plane for Large Negative ХGSM

The crossings of the magnetopause and low-latitude boundary layer by the THEMIS-B satellite in the spring of 2008 on the dusk flank under large negative XGSM (from –17RE to –19RE) are studied. The parameters of plasma and magnetic field are analyzed from the data of ESA and MGF instruments. The changes in the total pressure, magnetic field pressure, and plasma pressure component during the transition from the magnetosheath to the plasma sheet (PS) are analyzed. The values of plasma pressures under the magnetopause at the edge of the PS for the considered events are determined. The applicability of the obtained results to the determination of the position of the boundary between the tail current and the ring current is discussed.