@Article{LopezGonz:2017:MaBaSo,
author = "Lopez, Ramon E. and Gonzalez Alarcon, Walter Dem{\'e}trio",
affiliation = "{University of Texas at Arlington} and {Instituto Nacional de
Pesquisas Espaciais (INPE)}",
title = "Magnetospheric balance of solar wind dynamic pressure",
journal = "Geophysical Research Letters",
year = "2017",
volume = "44",
number = "7",
pages = "2991--2999",
month = "Apr.",
keywords = "magnetopause, bow shock, currents.",
abstract = "The magnetopause is the boundary established by pressure balance
between the solar wind flow in the magnetosheath and the
magnetosphere. Generally, this pressure balance is represented to
be between the solar wind, the dynamic pressure, and the magnetic
pressure of Earth's dipole field. The plasma actually in contact
with the magnetosphere is the slowed, compressed, and heated solar
wind downstream of the shock. The force exerted on the
magnetosheath plasma is the JxB force produced by the
Chapman-Ferraro current that flows on the magnetopause. Under
typical solar wind conditions of relatively high magnetosonic Mach
number flow (>6), this simple picture is a reasonable description
of the situation. However, under conditions of low solar wind
magnetosonic Mach number flow (similar to 2) the force on the
solar wind plasma is not exerted at the magnetopause and must be
exerted at the bow shock by currents that connect to the Region 1
currents. In this paper we present observations from two
magnetopause crossings observed by the Time History of Events and
Macroscale Interactions during Substorms spacecraft to compare and
contrast the force balance with the solar wind for two situations
with very different solar wind magnetosonic Mach numbers. Plain
Language Summary When the solar wind hits Earth's magnetic field,
the magnetic field pushes back on the solar wind. Typically, this
force is exerted at the boundary between Earth's magnetic field
and the solar wind. However, when the supersonic solar wind has a
low Mach number (about 2, as opposed to the typical value of >6),
the place where the force is exerted on the solar wind is at the
bow shock wave in front of Earth. This force is produced by an
electric current that flows on the bow shock and which connects to
currents that flow directly into Earth's ionosphere in the polar
regions. This paper presents spacecraft observations documenting
this unusual situation.",
doi = "10.1002/2017GL072817",
url = "http://dx.doi.org/10.1002/2017GL072817",
issn = "0094-8276",
language = "en",
targetfile = "lopez_magnetospheric.pdf",
urlaccessdate = "27 abr. 2024"
}