In this new study, Simon-Miller and her colleagues analyzed images taken by Cassini, NASA‚Äôs Voyager spacecraft, the Hubble Space Telescope and a decade‚Äôs worth of observations by amateur astronomers.
David Choi, a postdoctoral fellow at Goddard, stitched together about a hundred Cassini images to make each time-lapse movie, which zooms in on a single jet stream in Jupiter‚Äôs southern hemisphere. Cassini is currently in orbit around Saturn, but the spacecraft flew by Jupiter in 2000.
The videos show a line of small, dark, V-shaped features called ‚Äúchevrons‚ÄĚ along one edge of the jet stream. At the start, these chevrons are traveling west to east with the wind, but later, they are seen to ripple and move north and south.
‚ÄúThat‚Äôs the signature of the Rossby wave,‚ÄĚ Choi said in a statement. ‚ÄúThe chevrons in the fast-moving jet stream interact with the slower-moving Rossby wave, and that‚Äôs when we see the chevrons oscillate.‚ÄĚ
The researchers also found that these chevrons are tied to another type of wave in Jupiter‚Äôs atmosphere, called a gravity inertia wave.
‚ÄúA planet‚Äôs atmosphere is a lot like the string of an instrument,‚ÄĚ study co-author Michael Allison, of the NASA Goddard Institute for Space Studies in New York, said in a statement. ‚ÄúIf you pluck the string, it can resonate at different frequencies, which we hear as different notes. In the same way, an atmosphere can resonate with different modes, which is why we find different kinds of waves.‚ÄĚ
We can‚Äôt embed it, but go there to watch this fascinating video and to learn more about earth‚Äôs Rossby waves and their effect on our jet stream. A Rossby screen saver would be nice.