Premium
Magnetospheric quasi‐static response to the dynamic magnetosheath: A THEMIS case study
Author(s) -
Glassmeier KarlHeinz,
Auster HansUlrich,
Constantinescu Dragoş,
Fornaçon KarlHeinz,
Narita Yasuhito,
Plaschke Ferdinand,
Angelopoulos Vassilis,
Georgescu Edita,
Baumjohann Wolfgang,
Magnes Werner,
Nakamura Rumi,
Carlson Charles W.,
Frey Sabine,
McFadden James P.,
Phan Tai,
Mann Ian,
Rae I. Jonathan,
Vogt Joachim
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl033469
Subject(s) - magnetosheath , magnetopause , magnetosphere , physics , geophysics , dynamic pressure , solar wind , magnetohydrodynamics , magnetic field , magnetosphere of saturn , mechanics , quantum mechanics
Earth's magnetosphere is buffeted by the time‐varying solar wind. For the first time, the THEMIS mission, with its five spacecraft, directly allows to compare measurements in the magnetosheath and their response in the magnetopause boundary region, and the outer magnetosphere to this buffeting. During the time interval studied, the spacecraft moved almost along the stagnation streamline allowing to use Bernoulli's law to relate local observations of the plasma density, temperature, flow velocity, and magnetic field to the stagnation pressure. Magnetopause distance and velocity are determined assuming a quasi‐static response. The dynamics inferred is compared with actual observations by three of the THEMIS spacecraft. Assuming a radially moving Chapman‐Ferraro current layer also the outer magnetospheric magnetic field response is modelled and compared with magnetic field measurements. Most of the low‐frequency variability of the outer magnetosphere and magnetopause boundary can be understood as the result of a quasi‐static response of the magnetosphere to magnetosheath dynamic pressure variations.