What is a toroidal vortex, you might ask:
A toroidal vortex, also called a vortex ring, is a region of rotating fluid moving through the same or different fluid where the flow pattern takes on a toroidal (doughnut) shape. The movement of the fluid is about the poloidal or circular axis of the doughnut, in a twisting vortex motion. Examples of this phenomenon are a smoke ring or a microburst. Vortex rings were first mathematically analysed by the German physicist Hermann von Helmholtz, in his paper of 1867 On Integrals of the Hydrodynamical Equations which Express Vortex-motion Smoke rings have probably been observed since antiquity since they can easily be blown from the mouth.
Don't worry, I had no clue what they were either, but surprisingly it's something whales, dolphins, volcanoes, hydrogen bombs and man can do, and it's a pretty fascinating phenomenon.
If you want to learn how to make your own, the Surfing Scientist tells you how. All you need is a glass, water and some food coloring.
I need to do some shopping! This would be a fun photography project. I'm trying to think outside the box. And here.