The massive storm near the gas giant’s equator has subsided, but collisions with a series of anticyclones are likely only to occur on the surface.
The stormy centuries-old maelstrom of JupiterThe Great Red Spot was shaken but not destroyed by a series of anticyclones that hit it in recent years.
Smaller storms cause bits of red cloud to break off, reducing the larger storm in the process. But the new study found that these interruptions are “superficial.” They are visible to us, but are only superficial in the red spot, without affecting its full depth.
The new study was published in the Journal of Geophysical Research: Planets, AGU magazine for research on the formation and evolution of planets, moons, and objects in our solar system and beyond.
“The intense vorticity of [Great Red Spot], along with its greater size and depth compared to the interacting vortices, guarantees its long life, “said Agustín Sánchez-Lavega, professor of applied physics at the University of the Basque Country in Bilbao, Spain, and lead author of the new paper. As the larger storm absorbs these smaller storms, it “gains energy at the expense of its rotational energy.”
The Red Spot has been shrinking for at least the last 150 years, going from a length of about 40,000 kilometers (24,850 miles) in 1879 to about 15,000 kilometers (9,320 miles) today, and researchers are still unsure of the causes of the decrease, or even how the stain was formed in the first place. The new findings show that small anticyclones can help maintain the Great Red Spot.
Timothy Dowling, a professor of physics and astronomy at the University of Louisville, an expert in planetary atmospheric dynamics who was not involved in the new study, said “this is an exciting time for the Red Spot.”
Before 2019, the largest storm was only hit by a couple of anticyclones a year, while more recently it was hit by up to two dozen a year. “It really is getting hit. It was causing a lot of alarm, ”Dowling said.
Sánchez-Lavega and his colleagues were curious to see if these relatively smaller storms had disturbed his older brother’s spin.
The gas giant’s iconic feature is located near its equator, dwarfing Earth’s concepts of a major storm for at least 150 years from its first confirmed observation, although observations in 1665 may have been of the same storm. The Great Red Spot is about twice the diameter of Earth and blows at speeds of up to 540 kilometers (335 miles) per hour along its periphery.
“The [Great Red Spot] it is the archetype among vortices in planetary atmospheres, “said Sánchez-Lavega, adding that the storm is one of his” favorite characteristics in planetary atmospheres.
Cyclones such as hurricanes or typhoons generally revolve around a center with low atmospheric pressure, rotating counterclockwise in the northern hemisphere and clockwise in the south, either on Jupiter or on Earth. Anticyclones rotate in the opposite direction to cyclones, around a center with high atmospheric pressure. The Great Red Spot is itself an anticyclone, although it is six to seven times larger than the smaller anticyclones that have been colliding with it. But even these smallest storms on Jupiter are about half the size of Earth and about 10 times the size of the largest land-based hurricanes.
Sánchez-Lavega and his colleagues observed satellite images of the Great Red Spot for the past three years taken from the hubble space telescope, the Juno spacecraft orbiting Jupiter and other photos taken by a network of amateur astronomers with telescopes.
The team found that the smallest anticyclones traverse the high-speed peripheral ring of the Great Red Spot before circling the red oval. The smaller storms create some chaos in an already dynamic situation, temporarily changing the 90-day longitude oscillation of the Red Spot and “ripping the red clouds off the main oval and forming serpentines,” Sánchez-Lavega said.
“This group has done extremely careful, very painstaking work,” Dowling said, adding that the flaking of the red material that we see is similar to a crème brûlée effect, with an apparent eddy for a few kilometers on the surface that doesn’t have much impact in the 200 kilometers (125 miles) depth of the Great Red Spot.
Researchers still don’t know what has caused the reduction of the red spot for decades. But these anticyclones may be holding the storm giant for now.
“Ingestion of [anticyclones] it is not necessarily destructive; it can increase the rotation speed of the GRS, and perhaps for a longer period, keep it in a stable state, ”said Sánchez-Lavega.
Reference: “The Great Red Spot of Jupiter: strong interactions with incoming anticyclones in 2019” by A. Sánchez-Lavega, A. Anguiano-Arteaga, P. Iñurrigarro, E. García-Melendo, J. Legarreta, R. Hueso, JF Sanz- Requena, S. Pérez-Hoyos, I. Mendikoa, M. Soria, JF Rojas, M. Andrés-Carcasona, A. Prat-Gasull, I. Ordoñez-Extebarria, JH Rogers, C. Foster, S. Mizumoto , A. Casely, CJ Hansen, GS Orton, T. Momary and G. Eichstädt, March 17, 2021 ,.
DOI: 10.1029 / 2020JE006686