Climate Change on Jupiter
Storm Activity May Signal Jovian Temperature Fluctuations
Jupiter is famous for its Great Red Spot. This spot has persisted for at least 300 years, since it was first viewed through one of the first telescopes. This region of high pressure, frequently referred to as a storm, consists of clouds whose tops are higher and colder than the surrounding region.
Jupiter's Great Red Spot has had company in recent years. The appearance of Red Spot Jr. in 2005 and another smaller red spot in 2008, all in the same area, has led some to speculate that Jupiter is undergoing climate change.
Climate Change on Jupiter
The words "climate change" are big buzz words in the media at present, generally referring to man's alteration of Earth's atmospheric composition. Climate change has natural sources as well. Climate change has been occurring on the planets since long before man arrived. The climate change on Jupiter is unrelated to what is currently occurring on Earth.
Complicated atmospheric systems have cycles. Jupiter appears to be entering a new cycle. One of the paradoxes about Jupiter's atmosphere is that the upper level clouds have the same temperature at the poles as they do at the equator. In order for the temperature to be so homogeneous across the cloud tops of giant Jupiter, a lot of mixing must be going on.
Dr. Philip S. Marcus, Ph.D., Professor of Fluid Mechanics for the University of California at Berkeley, says, "When things move chaotically, they are really, really good at mixing." He compares the cloudy atmosphere to bumper cars, which constantly jostle each other and transfer energy.
Storms on the Merge
In the 1930s, a few large vortices were born on Jupiter. These storms persisted for decades, until finally, around 2000, they stopped repelling each other and merged. Marcus notes that "vortices come and vortices go," but the question of why has not been clearly established. Marcus wrote a paper theorizing what changes could be happening to cause the vortices to form or decay. Marcus's theory is that if the atmosphere of Jupiter is heating up, effects will start to show up, such as waves and vortices created from the instability. The changes should also be noticed from about 34 degrees south to north of the equator. Part of this climate change theory included the idea that it would take a while before the effects could be seen.
Atmospheres do not show immediate evidence of climate change. Examples of this can be seen on Earth. The winter solstice, when the sun is lowest in the sky and the daylight hours are fewest, marks the beginning of winter. Logically it would seem that the solstice should mark the midpoint of winter. In fact, it takes the atmosphere a while to react and adjust to the change of inputs.
Marcus's theory may be starting to prove itself out as we watch a rash of new spots appear on Jupiter in the time frame and location as his predictions.
For more on Jupiter's new red spots, read New Storms Spotted on Jupiter.
Source: Telephone interview with Phil Marcus.
