Velocity variations of an equatorial plume throughout a Jovian year

Analysis of features in the Equatorial Zone of Jupiter has shown that the equatorial plume reported by Pioneer 10 has existed for an 11-yr interval. During this interval the plume has shown an acceleration which can be interpreted as a constant component of 3 × 10^?8 m/sec² and a sinusoidal component which anticorrelates with the planetocentric declination of the Sun, D_S, and has an amplitude of ?0.96 m/sec per degree change of D_S. The sinusoidal component has been interpreted in terms of solar heating. Throughout this interval of time the Equatorial Zone has appeared abnormally dark and has contained many dark projections along the northern edge. When the plume approaches to within 25 to 30° of these features they are deflected in the direction of motion of the plume and then dissipate or become obscured as the plume passes. After passage of the plume normal features are again observed.     

On the coincidence of the position of Mercury with the 90-day oscillation of Jupiter's red spot

Recent observations have been utilized to investigate the proposed temporal connection between the 90-day oscillation of Jupiter's Red Spot and the inferior conjunction of Mercury. The oscillations appear to be synchronized with the inferior conjunction of a “mean Mercury” rather than the real Mercury implying that the period of oscillation of the Red Spot is constant. Although the probability of a synchronization due to chance is small, the failure of the oscillation to coincide with the motion of the real Mercury offers a strong argument against a physical connection between the two phenomena.     

Ground water whirls

Numerical experiments with steady-state ground water flow models show that spiraling flow lines occur in layered aquifers that have different anisotropic horizontal hydraulic conductivities in adjacent layers. Bundles of such flow lines turning in the same direction can be referred to as ground water whirls. An anisotropic layered block in a field of uniform horizontal flow results in one or more whirls with their axes in the uniform flow direction. The number of whirls depends on the number of interfaces between layers with different anisotropic properties. For flow to a well in an aquifer consisting of two anisotropic layers, with perpendicular major principal directions, whirls are found to occur in quadrants that are bounded by the principal directions of the hydraulic conductivity. The combined effect of flow to a well and a layered anisotropy implies that a single well in a system with a single anisotropic layer within an otherwise isotropic aquifer causes eight whirls. All adjacent whirls rotate in opposite directions.