Jupiter's Great Red Spot: Strong Interactions With Incoming Anticyclones in 2019. Issue 4 (9th April 2021)

• Record Type: Journal Article
• Authors: Sánchez‐Lavega, A.; Anguiano‐Arteaga, A.; Iñurrigarro, P.; Garcia‐Melendo, E.; Legarreta, J.; Hueso, R.; Sanz‐Requena, J. F.; Pérez‐Hoyos, S.; Mendikoa, I.; Soria, M.; Rojas, J. F.; Andrés‐Carcasona, M.; Prat‐Gasull, A.; Ordoñez‐Extebarria, I.; Rogers, J. H.; Foster, C.; Mizumoto, S.; Casely, A.; Hansen, C. J.; Orton, G. S.; Momary, T.; Eichstädt, G.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 4(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-04-09
• Subjects: Atmosphere -- dynamics -- Jupiter; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1029/2020JE006686
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: Jupiter's Great Red Spot (GRS), a giant anticyclone, is the largest and longest‐lived of all the vortices observed in planetary atmospheres. During its history, the GRS has shrunk to half its size since 1879, and encountered many smaller anticyclones and other dynamical features that interacted in a complex way. In 2018–2020, while having a historically small size, its structure and even its survival appeared to be threatened when a series of anticyclones moving in from the east tore off large fragments of the red area and distorted its shape. In this work, we report observations of the dynamics of these interactions and show that as a result the GRS increased its internal rotation velocity, maintaining its vorticity but decreasing its visible area, and suffering a transient change in its otherwise steady 90‐day oscillation in longitude. From a radiative transfer analysis and numerical simulations of the dynamics we show that the interactions affected the upper cloud tops of the GRS. We argue that the intense vorticity of the GRS, together with its larger size and depth compared to the interacting vortices, guarantees its long lifetime. Plain Language Summary: Jupiter's Great Red Spot (GRS) is a giant anticyclone with a length that has shrunk since 1879 from ∼ 40, 000 km to its current value of 15, 000 km. The GRS is the longest‐lived of all the planetary vortices, observed perhaps since the 17th century. During its history, the GRS has encountered a variety of smaller anticyclones and other dynamical features, surviving these interactions. In 2018–2020, a series of anticyclones interacted with it, and tore off large fragments of its red area (called "flakes"), eroding and distorting its oval shape, and apparently threatening its survival. The interactions produced an increase in the GRS internal rotation velocity accompanied by a transient increase in the period and amplitude of its steady 90‐day oscillation in longitude. From the analysis of the reflectivity of the GRS and flakes and model simulations of the dynamics of the interactions we find that these events are likely to have been superficial, not affecting the full depth of the GRS. The interactions are not necessarily destructive but can transfer energy to the GRS, maintaining it in a steady state and guaranteeing its long lifetime. Key Points: In 2018–2020, Jupiter's Great Red Spot interacted with series of anticyclones, losing part of its visible red area and distorting its shape The Great Red Spot (GRS) increased its tangential velocity; it did not change its vorticity, but did temporarily change its 90‐day oscillation in longitude Dynamical and radiative transfer modeling shows that the interactions affected the upper cloud of the GRS with no risk for its survival