Phase dispersion relation of the 5-micron hot spot wave from a long-term study of Jupiter in the visible

Abstract

We present a long-term study at visible wavelengths of the motions and spatial distribution of the hot spots at 7°N of Jupiter. This research involves seven years of observations of the planet between 1979 and 2002 and includes data from Voyagers 1 and 2, Hubble Space Telescope, and a number of ground-based observatories. Our analysis of the North Equatorial Belt (NEB) dark projections (DPs) velocities and wave numbers shows that a dispersion relationship exists, with the DPs velocity (ranging from 97 to 113 ms -1) slightly increasing with wave number (ranging from 6 to 20, although usually 8-12). We interpret this relationship in terms of a superposition of equatorial Rossby waves traveling along the planet and confined to the upper troposphere. The resulting equivalent depth for the waves on an incompressible fluid is 12 km, and they move relative to a background flow with speed 140 ms-1, a result in good agreement with previous analysis of the wave interpretation for hot spot motions as observed in the infrared. Copyright 2006 by the American Geophysical Union.