The IMF Clock Angle Effect on the Tail Cross Section of the Martian Magnetic Pileup Boundary and Bow Shock

Abstract

Using a three-dimensional global magnetohydrodynamic (MHD) simulation model, we investigate the effects of different interplanetary magnetic field (IMF) clock angles on the tail configuration of the Martian magnetic pileup boundary (MPB) and bow shock (BS). The study reveals the following: (1) The cross sections of the tail MPB and BS are approximately elliptical. The MPB tail cross section generally elongates in the direction of the IMF clock angle, whereas the BS tail cross section is roughly elongated perpendicular to the IMF clock angle direction. (2) An IMF with a northward component can cause the tail cross section of the MPB to shift slightly to the south when the intense crustal magnetic fields are located on the dayside. (3) As the tail distance from Mars increases, the eccentricity of the cross section ellipses of both the MPB and BS tail increases, as well as the major and minor axes. Additionally, the major and minor axes of the tail MPB’s cross section ellipses begin to decrease at the far magnetotail, suggesting that the Martian MPB tail might be a closed structure on the nightside.