South-north asymmetry of proton density distribution in the Martian magnetosheath

作者：Jing Wang,XiaoJun Xu,Jiang Yu,YuDong Ye

摘要：We perform a statistical analysis of data from the Mars Atmosphere and Volatile Evolution (MAVEN) project on the global distribution of protons in the Martian magnetosheath. Our results show that the proton number density distribution has a south-north asymmetry. This south-north asymmetry is most likely caused by the south-north asymmetric distributions of the crustal magnetic fields at Mars. The strong crustal magnetic fields push the inner boundary of magnetosheath to a higher altitude in the southern hemisphere. Due to the outward movement of the inner boundary of the magnetosheath, a compressed magnetosheath forms, causing subsequent increases in proton number density, thermal pressure, and total pressure. Eventually, a balance is reached between the increased total pressure inside the magnetosheath and the increased magnetic pressure inside the induced magnetosphere. Our statistical study suggests that the Martian crustal magnetic fields can strongly affect the proton number density distribution in the Martian magnetosheath.

发文机构：State Key Laboratory of Lunar and Planetary Sciences School of Atmospheric Sciences

关键词：MartianMAGNETOSHEATHsouth-northasymmetryprotondensitydistributionCRUSTALmagneticfield

分类号： O57[理学—粒子物理与原子核物理][理学—物理]