New Images Show Storms Powering Saturn's Jet Streams

The Cassini space probe brought new evidence that contradicts older theories, by showing that rotating eddies (Saturn's giant storms) are driving Saturn's jet stream winds, not the other way around.

"Intuition would say that the eddies take energy out of the jets, because of the friction and tugging of the storms. Instead, what we find is that they are pumping energy into the jets," said Andrew Ingersoll, a Cassini imaging team member with the California Institute of Technology, Pasadena, California.

"The new information about how Saturn's jet streams are powered is exactly the opposite of what we thought prior to Cassini," said Anthony Del Genio of NASA's Goddard Institute for Space Studies, New York, imaging team member and lead author of a paper describing this research.

The jet streams on Saturn's surface are atmospheric movements that carry clouds to the East or to the West at great speeds, sheared-out cloud features associated with the storms raging the surface.

It seems that the storms actually seem to produce the jet streams, much like rotating gears that power a conveyor belt.

"While we thought the conveyor belt -- in this case, the jet streams -- powered the rotating eddies, we now think the opposite: the rotating eddies power the jet streams," said Del Genio. They do this by pumping energy into the jets, thus generating their movement and speed.

The discovery has been made with the help of the Cassini space probe, which tracked the movement of cloud features on the ringed planet's southern hemisphere.

After analyzing images of migrating clouds, taken every 10 hours, they reached the conclusion that the storms (which even point in the same direction as the jets), are actually doing all the work.

Recently, the same process has been proven to occur on Jupiter, in data obtained when Cassini flew by that planet on its way to Saturn, but it had never been demonstrated on Saturn's surface.