Premium
Correlating east‐west asymmetries in the Jovian magnetosphere and the Io sodium cloud
Author(s) -
Smyth William H.,
Combi Michael R.
Publication year - 1987
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/gl014i009p00973
Subject(s) - jovian , magnetosphere , jupiter (rocket family) , physics , atmosphere of jupiter , electric field , torus , plasma , astrophysics , atmospheric sciences , astronomy , geophysics , geology , spacecraft , planet , saturn , geometry , mathematics , quantum mechanics
Three east‐west intensity asymmetries in the Jupiter system that would appear to an Earth observer in optical S + , extreme ultraviolet S ++ and optical Na emissions are reviewed. The three asymmetries imply that some combination of the plasma torus number densities and electron temperature is, on the long‐term average, larger west of Jupiter than east of Jupiter. A small east‐to‐west electric field, previously proposed to explain the ion intensity asymmetries, is also shown to provide a natural explanation for the sodium intensity asymmetry. A long‐term average east‐to‐west electric field of ∼3 mV/m and a corresponding west‐to‐east offset of ∼0.16 Jupiter radii for the plasma torus at Io's orbital distance is implied. On a shorter time scale, the east‐west electric field appears to be time variable and may be readily monitored from Earth by observations of the sodium cloud.