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Title: Models for Jupiter's decametric arcs

Journal Article · · J. Geophys. Res.; (United States)

Several papers of the present issure attempt to explain the remarkable arc-shaped structures that dominate Jupiter's decametric emissions as recorded by Voyagers 1 and 2. Since these papers approach this subject from very different points of view, the introduction is designed to place these perspectives in context. The present paper understands these arcs in terms of magnetic fine structure undetected by Pioneer 11 on account of its rather large closest approach distance (50 or 60 times the smallest scales in the structures involved.) The nested sequences of arcs manifest the occurrence of widespread fine structures, similar in size and shape to the white ovals so ubiquitous over Jupiter's visible surface. An arc concave toward increasing time (vertex early) occurs at the east limb passage of such a structure, and the arc convex (vertex late) occurs at the west limb passage. This is consistent with the early source producing vertex early arcs and the late (and main) source producing vertex late arcs. Since arcs seem naturally to classify themselves into two large families: greater arcs (reaching frequencies > or =20 MHz) and lesser arcs 20 MHz): polarized invariably right hand, or right hand or left hand symmetrically in longitude, respectively, we identify the right-hand greater arcs with north polar cap sources, the lesser right-hand (left hand) arcs with north (south) temperature sources, and call for the absence of fine magnetic structure in Jupiter's southern polar cap.

Research Organization:
The John Hopkins Univ., Laurel, Maryland
OSTI ID:
5789802
Journal Information:
J. Geophys. Res.; (United States), Vol. 86:A10
Country of Publication:
United States
Language:
English