Constraints on the latitudinal profile of Jupiter's deep jets

TL;DR

This study uses gravity measurements to constrain the depth and structure of Jupiter's deep jets, showing that equatorial winds extend deep while poleward jets may differ from cloud-level observations.

Contribution

It provides new constraints on the latitudinal profile and depth of Jupiter's jets using gravity data, highlighting the inward projection and decay of winds.

Findings

Equatorial winds extend unaltered to thousands of kilometers deep.

Poleward jets may differ from cloud-level winds but are constrained in their strength.

Winds must project inward along Jupiter's spin axis and decay radially.

Abstract

The observed zonal winds at Jupiter's cloud tops have been shown to be closely linked to the asymmetric part of the planet's measured gravity field. However, other measurements suggest that in some latitudinal regions the flow below the clouds might be somewhat different from the observed cloud-level winds. Here we show, using both the symmetric and asymmetric parts of the measured gravity field, that the observed cloud-level wind profile between 25$^{\circ}$S and 25$^{\circ}$N must extend unaltered to depths of thousands of kilometers. Poleward, the midlatitude deep jets also contribute to the gravity signal, but might differ somewhat from the cloud-level winds. We analyze the likelihood of this difference and give bounds to its strength. We also find that to match the gravity measurements, the winds must project inward in the direction parallel to Jupiter's spin axis, and that their decay inward should be in the radial direction.