The Evolving Flow of Jupiter's White Ovals and Adjacent Cyclones

TL;DR

This study analyzes the evolution of Jupiter's White Ovals and adjacent cyclones, revealing changes in wind speeds, morphology, and dynamical similarities to the Great Red Spot over multiple epochs.

Contribution

It provides new insights into the wind dynamics and morphological evolution of Jupiter's White Ovals and cyclones across different observational periods.

Findings

Northern periphery of Oval BA increased in speed by 20 m/s.

Southern rim speeds of Oval BA reached ~140-150 m/s.

Cyclonic features exhibit coherent high-speed collars around quiescent interiors.

Abstract

We present results regarding the dynamical meteorology of Jupiter's White Ovals at different points in their evolution. Starting from the era with three White Ovals FA, BC, and DE (Galileo), continuing to the post-merger epoch with only one Oval BA (Cassini), and finally to Oval BA's current reddened state (New Horizons), we demonstrate that the dynamics of their flow have similarly evolved along with their appearance. The northern periphery of Oval BA increased in speed by 20 m/s from Cassini to New Horizons, ending up at a speed nearly identical to that of the northern periphery of Oval DE during Galileo. However, the peak speeds along the southern rim of the newly formed Oval BA were consistently faster than the corresponding speeds in Oval DE, and they increased still further between Cassini and New Horizons, ending up at ~140 to 150 m/s. The modest strengthening of the winds in Oval BA, the appearance of red aerosols, and the appearance of a turbulent, cyclonic feature to Oval BA's northwest create a strong resemblance with the Great Red Spot from both a dynamical and morphological perspective. In addition to the White Ovals, we also measure the winds within two compact cyclonic regions, one in the Galileo data set and one in the Cassini data set. In the images, these cyclonic features appear turbulent and filamentary, but our wind field reveals that the flow manifests as a coherent high-speed collar surrounding relatively quiescent interiors. Although less studied than their anticyclonic cousins, these cyclones may offer crucial insights into the planet's cloud-level energetics and dynamical meteorology.