Morning in Japan starts with miso soup. Looking at miso soup, you can clearly see the convective motion of fluid.
On the surface of hot miso soup, evaporation is prolific, and the surface is continually cooled. Cold miso soup becomes a little heavier so it sinks. This motion is made visible quite nicely by the little granules in miso soup.
Looking at this convection, places where miso is
spouted up and sucked down
near the surface are clearly visible. This kind of thermal convection is called Rayleigh-Bérnard convection.