Open AccessOrientation and motion of a discontinuity from single‐spacecraft measurements of plasma velocity and density: Minimum mass flux residue
Author(s) -
Sonnerup B. U. Ö.,
Haaland S.,
Paschmann G.,
Lavraud B.,
Dunlop M. W.,
Rème H.,
Balogh A.
Publication year - 2004
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 - 10.1029/2003ja010230
Subject(s) - magnetopause , physics , discontinuity (linguistics) , computational physics , spacecraft , magnetic field , plasma , chord (peer to peer) , reference frame , mathematics , solar wind , mathematical analysis , frame (networking) , computer science , quantum mechanics , astronomy , telecommunications , distributed computing
A simple analytical solution is presented to the problem of determining the orientation and motion of a one‐dimensional discontinuity in plasma velocity and density, measured by a single spacecraft as the discontinuity moves past it. The method developed is called Minimum Massflux Residue (MMR). Illustrations of the method, based on Cluster measurements in the dawnside magnetopause region, are given, and the results are compared with those obtained by other methods, such as Minimum Faraday Residue (MFR) analysis and minimum variance analysis of the magnetic field combined with deHoffmann‐Teller frame determination (MVAB/HT). The results indicate that the Cluster plasma measurements are of sufficiently high quality for MMR to yield normal vectors and magnetopause speeds that agree well with those obtained from MFR and also from a constrained version of MVAB/HT (the constraint being 〈 B 〉 · n = 0). We also show how results from more than one method can be combined to produce a single prediction of the normal vector and speed.