Question

How do supercells acquire their rotation?

O two low pressure systems merge
O the clash of warm and cold air masses
O the coriolis force the thunderstorm updraft
O tilts rotation about a horizontal axis owing to shear into the vertical

Answer 1

Supercells gain rotation when horizontal rotation, caused by differing wind speeds and directional wind shear, is tilted into a vertical rotation by the updraft within a thunderstorm, leading to the formation of a tornado. The Coriolis force influences larger weather systems but is not the primary factor in the rotation of supercells.

Step-by-step explanation:

Supercells acquire their rotation through a mechanism related to the difference in wind speeds at varying altitudes and influenced by directional wind shear. This rotation begins when horizontal rolling motion, created by the shear between winds moving at different speeds (such as the strong cold winds of the jet stream and the weaker, warmer winds from the Gulf of Mexico), is tilted into a vertical orientation by a strong updraft within a thunderstorm. The rotation about a horizontal axis is shifted into a vertical axis, leading to the development of a rotating updraft known as a mesocyclone, which is the precursor to a tornado.

While the Coriolis force does affect the rotation of larger-scale weather systems like hurricanes and tropical cyclones, causing them to rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, it is the wind shear in combination with updraft that is mostly responsible for the rotation in supercells.