Supplementary Movie Legend
Figure 3 of the Letter shows stills from this movie, which is a numerical simulation of
two anticyclonic White Ovals (red) and a small intervening cyclone (blue) trapped in
the trough of a Rossby wave. The wave lies on the interface of the dark and light blue.
Initially a small cyclone (blue) lies to the east of the trough. The untrapped cyclone
travels to the west, while the trough and its trapped three vortices travel to the east.
The untrapped cyclone collides with the trapped vortices, which reverses the direction
of travel of the untrapped cyclone. The perturbation to the trapped vortices is enough
to allow the trapped cyclone to pass to the west of the White Oval to its west. Soon
after the two White Ovals become adjacent, they merge. More information can be
found in Youssef, A. and Marcus, P. S. The dynamics of jovian white ovals from
formation to merger. P. S. Icarus, 162, 74—93 (2003).