NASA's Cassini spacecraft has given Jet Propulsion Laboratory (JPL) scientists a greater understanding of the massive storm on Saturn's surface.

According to a press release, the storm, which has been active since late 2010, is also one of the most intense on record for Saturn. It has also impressed scientists with its ability to exhume deep-seeded water ice. It is also the first ever evidence of water anywhere in Saturn's atmosphere.

Water ice usually appears deep in the atmosphere of gas giants like Saturn, but in this case, it was more buried than normal.

"The new finding from Cassini shows that Saturn can dredge up material from more than 100 miles [160 kilometers]," said Kevin Baines, a co-author of the paper who works at the University of Wisconsin (UW)-Madison and NASA's JPL in Pasadena, Calif. "It demonstrates in a very real sense that typically demure-looking Saturn can be just as explosive or even more so than typically stormy Jupiter."

Because of its greater distance from the sun, a year on Saturn is about the equivalent of 30 years on Earth. Saturn experiences a great storm about once every one of its years.

Cassini was launched about one Earth year after the current storm developed and the study is based off spacecraft's detailed images of the ringed planet. Lead author Lawrence Sromovsky, also of UW, and his team found the cloud particles on the surface of the planet to be made up of water ice, ammonia ice and unclear third constituent.

Saturn's atmosphere is comparable to a multi-layered sandwich, with water ice clouds on the bottom, ammonia hydrosulfide clouds in the middle and ammonia clouds on top. With water particles appearing toward the top, the layers have seemingly become jumbled.

"We think this huge thunderstorm is driving these cloud particles upward, sort of like a volcano bringing up material from the depths and making it visible from outside the atmosphere," said Sromovsky. "The upper haze is so optically thick that it is only in the stormy regions where the haze is penetrated by powerful updrafts that you can see evidence for the ammonia ice and the water ice. Those storm particles have an infrared color signature that is very different from the haze particles in the surrounding atmosphere."

If Saturn's storm were to occur on Earth, the scientists estimated the clouds would be about 10 to 20 times taller than an Earth storm with vertical winds as strong as 300 miles-per-hour.