Formation mechanism of Jupiter's Great Red Spot

Determine the dynamical formation mechanism that gave rise to Jupiter's Great Red Spot, specifying the physical processes and initial atmospheric disturbances within Jupiter's zonally sheared flow at planetographic latitudes approximately 22–24°S that produced the long-lived anticyclonic vortex comprising the red oval and its surrounding Hollow.

Background

Jupiter's Great Red Spot (GRS) is a giant anticyclonic vortex characterized by a red oval and a surrounding Hollow, with winds indicating that both regions together define the vortex’s dynamical area. Despite centuries of observation, the exact genesis of this enduring feature has not been definitively established.

Guided by historical records and modern measurements, the paper tests three plausible origin scenarios using Shallow Water and EPIC numerical models: formation by a moist-convective superstorm, by mergers of multiple anticyclones, and by the emergence of an elongated proto-vortex originating from a South Tropical Disturbance in the meridionally sheared zonal winds. The authors find the superstorm and merger mechanisms unlikely and argue that a disturbance between opposing jets is more plausible, but they stop short of a definitive determination.