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Direct observation of a tangential electric field component at the magnetopause
Author(s) -
Mozer F. S.,
Torbert R. B.,
Fahleson U. V.,
Fälthammar C.G.,
Gonfalone A.,
Pedersen A.,
Russell C. T.
Publication year - 1979
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/gl006i004p00305
Subject(s) - magnetopause , magnetosheath , bow shock (aerodynamics) , physics , solar wind , geophysics , electric field , magnetosphere , computational physics , magnetic field , mechanics , shock wave , quantum mechanics
The first direct, in situ measurements of the quasi‐static electric field at and near the magnetopause, in the magnetosheath, bow shock, and solar wind, have been made on the ISEE‐1 satellite. Both the large scale average electric field and the fine scale field observed during a magnetopause crossing show the existence of significant tangential electric field components on both sides of the magnetopause, in agreement with the requirements of reconnection theories. The data in the satellite frame also show significant normal electric field components that typically point towards the magnetopause on both sides, corresponding to plasma flows towards dawn, as expected for the pre‐noon magnetopause crossings. In combination with ISEE‐1 and ISEE‐2 magnetic field data, these measurements also suggest that a magnetopause passage over the spacecraft occured at a velocity of 20±10 km/s, that the magnetopause thickness was 300±150 km, and that the local Ī·Ē dissipation was 70±20 watts/km². This observed local level of power dissipation would correspond to a total power of 10 12 watts, if it existed over the entire front of the magnetopause.