Antarctic polar explorers near the Ukrainian station Akademik Vernadskyy photographed an unusual phenomenon – clouds that resemble shells or sea waves.
They shared the photos on the page of the National Antarctic Research Center.
“The main characters of these photos are not the penguins, but the wavy clouds. Such a special phenomenon occurs due to the Kelvin-Helmholtz instability: when two flows with different density and speed meet and turbulence appears at their boundary. Shells are formed”, – explained the scientists.
Polar explorers noted that instability can occur at the boundary of one or two different environments and not necessarily in air. Such an example can also be considered the waves on the surface of the water, which are formed under the action of the wind. Sometimes they lose their stability, due to which foamy “shells” can be observed on top of the waves. In the case of cumulus clouds, different layers of the troposphere interact. These “sky shells” appear due to temperature differences, when the upper layer of air is warmer than the lower layer.
“The upper warm flow moves faster and clings to the lower – slower and colder. Shell waves are formed at the limit of their interaction,” the Ukrainian polar explorers explain.
Most of these atmospheric waves remain invisible forever. They can be seen under certain conditions – when at the boundary of the layers there is air saturated with moisture, which is taken up by the upward waves.
