Harvard Researchers Determine Weather on Jupiter and Saturn May Be Driven by Unique Factors

Three researchers — two from Harvard and one from the University of Alberta — have conducted simulations that suggest weather on Jupiter and Saturn may be influenced by different factors than those on Earth.

Harvard postdoctoral fellow Rakesh K. Yadav, Harvard geophysics professor Jeremy Bloxham, and University of Alberta associate professor Moritz Heimpel published the study in the journal Science Advances on Nov. 13.

The researchers simulated convection — the process of warmer fluid rising and cooler fluid sinking — in rotating spherical shells that mimic Jupiter and Saturn’s atmospheres. While surface-level atmospheric mechanisms largely motivate Earth’s weather, the researchers found that Jupiter and Saturn’s weather may instead stem from these much deeper convection patterns.

Previous studies on the weather of large planets like Jupiter and Saturn have been broadly separated into two schools of thought, Yadav said in an interview. The former group believes that weather on these giant planets comes from a thin layer of atmosphere near the planets’ surfaces, similar to Earth. The latter group — which includes Yadav, Bloxham, and Heimpel — argues that deeper internal forces may account for the planets’ unique weather formations.

“We belong to that group, where we think the atmospheres — the features we’ve seen on the surfaces — are likely very, very deep,” he said.

Yadav, Bloxham, and Heimpel’s research focused on two simulations. The first provided insights into the spontaneous generation of weather-related phenomena like zonal jets, hurricanes, and cyclones.

Although the researchers expected to find zonal jets — which are bands around the planet, similar to jet streams — and hurricane-like storms in the simulations, Yadav said the most surprising findings were the cyclones.

“We ended up finding giant cyclones, cyclones that were as large or sometimes even larger than Jupiter’s Great Red Spot. So that was entirely unexpected,” he said.

The second simulation demonstrated how the dynamo region — an electrically conducting fluid region traditionally understood to be inert — may actually play a significant role in initiating and continuing anticyclones. Anticyclones are storms similar to cyclones, but they rotate around a center of high atmospheric pressure.

“On the basis of these two case studies, we can begin piecing together a global picture of the deep convection-driven fluid dynamics occurring in Jupiter and Saturn,” the researchers wrote in their article.

Yadav underscored that simulations provide researchers with the opportunity to analyze the internal forces behind specific planetary phenomena.

“In planets, we can’t go inside and look at how things are changing with time. But in our simulation, of course, we could do that,” he said. “So that’s why in our paper, we could state that this giant Great Red Spot kind of feature in our model is connected to the inside of the planet.”

Yadav said that he hopes the simulations will serve as a launching point for future discoveries.

“We are also in the process of just analyzing it even more. There’s so much data, you can imagine doing a lot more things,” he said.