This sharp contrast in temperature leads to a pressure difference and thus a steep pressure gradient. This causes the air to move faster at this frontal boundary. Describe how the conservation of angular momen-tum plays a role in the formation of a jet stream. M for mass, v for speed and r for radius of the distance from the axis around which the mass is rotating. The sum of mvr before an event has to equal mvr after an event.
Conservation of momentum dictates that both products of mvr have to remain equal.
So as r decreases, v increases proportionally.