Washington: Researchers have developed a new model that will help them understand why Jupiter`s Great Red Spot - which is big enough to engulf the Earth twice or thrice - has not disappeared till now.
Pedram Hassanzadeh, a postdoctoral fellow at Harvard University, and Philip Marcus, a professor of fluid dynamics at the University of California, Berkeley, will present his work at the annual meeting of the American Physical Society`s Division of Fluid Dynamics in Pittsburgh on November 25.
To probe the mystery of the Red Spot`s survival, Hassanzadeh and Marcus built a model of their own, which differed from existing models as it was fully 3D and had very high resolution.
Many vortex models focus on the swirling horizontal winds, where most of the energy resides. Vortices also have vertical flows, but these have much less energy.
Hassanzadeh said that in the past, researchers either ignored the vertical flow because they thought it was not important, or they used simpler equations because it was so difficult to model.
Yet the vertical motion turns out to hold the key to the Red Spot`s persistence. As the vortex loses energy, the vertical flow transports hot gases from above and cold gases from below the vortex toward its center, restoring part of its lost energy.
The model also predicts a radial flow, which sucks winds from the high-speed jet streams toward the vortex center. This pumps energy into the vortex, enabling it to last longer.
According to Hassanzadeh, the same vertical flow could explain why oceanic vortices, such as those formed near the Straits of Gibraltar, can last for years in the Atlantic Ocean. Their vertical flow plays a role in the ocean ecosystem by lifting nutrients to the surface.
Vortices may also midwife the formation of stars and planets, lasting for millions of years as they pull interstellar dust and rocks into large masses.
