The gas planet’s near-equatorial giant storm shrinks, but continually absorbs energy from a series of smaller, reverse vortices that strike it.
A century-old cyclone called the Great Red Spot on Jupiter swings but has not been destroyed by a series of inverted vortices that have crashed into it in recent years. Smaller storms cause individual red clouds to separate, causing larger storms to narrow during the interaction. But new research, published March 17 in the journal Geophysical Research: Planets, shows that this disturbance only occurs on the surface. Researchers can observe them, but they don’t impact deep within the Great Red Spot.
“The extremely high rotational speed of the great red spot, combined with its size and depth compared to the surrounding interactive vortices, guarantees it a long lifespan,” says Agustín Sánchez-Lavega, physics application professor at the Basque University of Bilbao, Spain, says the team leader. “When a larger hurricane absorbs small storms, it accumulates the energy of the tornado.”
The great red spot has been shrinking for at least 150 years, its length increasing from about 40,000 km in 1879 to 15,000 km today. Researchers still don’t know for sure the cause of this miniature, or how the storm initially formed. New research results show that small reverse vortices can help the Big Red Streak survive.
Timothy Dowling, professor of physics and astronomy at the University of Louisville, said before 2019 a larger hurricane collided with just two reverse vortices per year, but recently it could experience dozens of vortices in one year. Sánchez-Lavega et al. Are curious whether relatively small storms affect the Great Red Spot vortex. Jupiter’s famous giant hurricane is located near the equator, about twice the diameter of Earth, and has winds of up to 540 km / h along its circumference.
Tornadoes such as low pressure tropical cyclones always revolve around the central region at low atmospheric pressure, rotate counterclockwise in the northern hemisphere, and clockwise in the southern hemisphere. The reverse vortex rotates in the opposite direction of the tornado, around the central area of high atmospheric pressure. The large red spot itself is a retrograde vortex, although it is 6-7 times larger than the smaller inverted vortices that pierce it. But even these smaller storms on Jupiter are about half the size of Earth and 10 times the largest hurricane on Earth.
Sánchez-Lavega and his colleagues look at satellite images of the Big Red Spot over the past three years taken from the Hubble Space Telescope, the Juno spacecraft orbiting Jupiter, and the array of astronomers’ telescopes. They noticed that the small reverse vortex passed through the circumference of the large red spot before circling around it. They cause some confusion, temporarily altering the 90-day oscillation cycle of the Great Red Spot, tearing up red clouds and producing multiple drafts.
