Open AccessMESSENGER observations of dipolarization events in Mercury's magnetotail
Author(s) -
Sundberg Torbjörn,
Slavin James A.,
Boardsen Scott A.,
Anderson Brian J.,
Korth Haje,
Ho George C.,
Schriver David,
Uritsky Vadim M.,
Zurbuchen Thomas H.,
Raines Jim M.,
Baker Daniel N.,
Krimigis Stamatios M.,
McNutt Ralph L.,
Solomon Sean C.
Publication year - 2012
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2012ja017756
Subject(s) - substorm , physics , magnetic field , plasma sheet , mercury (programming language) , adiabatic process , plasma , current sheet , population , spacecraft , geophysics , astrophysics , magnetohydrodynamics , computational physics , magnetosphere , astronomy , demography , quantum mechanics , sociology , computer science , thermodynamics , programming language
Several series of large dipolarization events are documented from magnetic field observations in Mercury's magnetotail made by the MESSENGER spacecraft. The dipolarizations are identified by a rapid (∼1 s) increase in the northward component of the magnetic field, followed by a slower return (∼10 s) to pre‐onset values. The changes in field strength during an event frequently reach 40 nT or higher, equivalent to an increase in the total magnetic field magnitude by a factor of ∼4 or more. The presence of spatially constrained dipolarizations at Mercury provides a key to understanding the magnetic substorm process in a new parameter regime: the dipolarization timescale, which is shorter than at Earth, is suspected to lead to efficient non‐adiabatic heating of the plasma sheet proton population, and the high recurrence rate of the structures is similar to that frequently observed for flux ropes and traveling compression regions in Mercury's magnetotail. The relatively short lifetime of the events is attributed to the lack of steady field‐aligned current systems at Mercury.