LASP Science Seminars

Jupiter’s Great Red Spot (GRS) has been observed for almost 200 years. This remarkably long-lived atmospheric feature changes over time on timescales of decades (gradual shrinking) to months (oscillations). Some variability, like the extension of red “flakes” or “streamers” stretching for up to 14,000 km outside the vortex, may be due to interactions with smaller vortices in the surroundings of the GRS. Within the past decade, our understanding of the vertical structure of the GRS has improved thanks to many new groundbreaking observational datasets. The Juno spacecraft has measured microwave emission and gravitational anomalies suggesting a depth of the feature of about 300 km. The James Webb Space Telescope measured the GRS cold anomaly in the upper parts of the vortex, where prior ground-based and spacecraft data found a high concentration of haze particles. The upper layers of the feature are also where red “chromophores” give the vortex its distinctive color. Comparing Great Red Spot to other planetary vortices—such as eddies in the Earth’s oceans and dark spots on Neptune—helps us to understand the unique structure and dynamics of Jupiter’s atmosphere in the context of other environments.