Mercury's cross‐tail current sheet: Structure, X‐line location and stress balance

Poh, Gangkai, Slavin, James A., Jia, Xianzhe, Raines, Jim M., Imber, Suzanne M., Sun, Wei‐Jie, Gershman, Daniel J., DiBraccio, Gina A., Genestreti, Kevin J. and Smith, Andy (2017) Mercury's cross‐tail current sheet: Structure, X‐line location and stress balance. Geophysical Research Letters, 44 (2). pp. 678-686. ISSN 0094-8276

Geophysical Research Letters - 2016 - Poh - Mercury s cross‐tail current sheet Structure X‐line location and stress.pdf - Published Version

Download (1MB) | Preview
Official URL:


The structure, X-line location, and magnetohydrodynamic (MHD) stress balance of Mercury's magnetotail were examined between −2.6 < XMSM < −1.4 RM using MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) measurements from 319 central plasma sheet (CPS) crossings. The mean plasma β in the CPS calculated from MESSENGER data is ~ 6. The CPS magnetic field was southward (i.e., tailward of X-line) ~ 2–18% of the time. Extrapolation of downtail variations in BZ indicates an average X-line location at −3 RM. Modeling of magnetic field measurements produced a cross-tail current sheet (CS) thickness, current density, and inner CS edge location of 0.39 RM, 92 nA/m2 and −1.22 RM, respectively. Application of MHD stress balance suggests that heavy planetary ions may be important in maintaining stress balance within Mercury's CPS. Qualitative similarities between Mercury's and Earth's magnetotail are remarkable given the differences in upstream conditions, internal plasma composition, finite gyro-radius scaling, and Mercury's lack of ionosphere.

Item Type: Article
Additional Information: Funding Information: All data analyzed in this paper are archived with the NASA Planetary Data System. Support was provided by NASA Discovery Data Analysis Program grants NNX15K88G and NNX15AL01G, Heliophysics Supporting Research NNX15AJ68G, Living With a Star NNX16AJ67G, and Solar System Workings Program grant NNX15AH28G to the University of Michigan. D.J.G. and G.A.D. were supported by NASA ROSES grant NNX16AJ05G. G.A.D. was supported by a NASA Postdoctoral Program appointment at the NASA Goddard Space Flight Center, administered by Universities Space Research Association through a contract with NASA. S.M.I. acknowledges the support of the Leverhulme Trust.
Uncontrolled Keywords: cross-tail current sheet, magnetotail structure, Mercury, Near-Mercury Neutral Line, stress balance
Subjects: F300 Physics
F500 Astronomy
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Rachel Branson
Date Deposited: 07 Nov 2022 11:25
Last Modified: 07 Nov 2022 11:30

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics