# Coriolis force relation to wind velocity

I'm learning coriolis effect on Winds moving from equator towards North pole. This is for geography.

Question: Why is coriolis force stronger for winds having larger speed(larger component of Northward velocity)?

The reason the coriolis effect (for north-south direction) is proportional to velocity is related to the concept of conservation of angular momentum.

The air mass of the Earth is co-rotating with the Earth. That means the applicable momentum is angular momentum instead of linear momentum.

(Incidentally, the general coriolis effect is the same for any direction of motion. That is: the effect is not exclusive to north-south motion.)

In the image the point where the vertical and horizontal axis cross coincides with the center of circumnavigating motion.

The dotted line represents the trajectory of an object that is circumnavigating counterclockwise, and being pulled closer to the axis of circumnavigation.

In the diagram the centripetal force is decomposed in two perpendicular components, one tangent to the instantaneous velocity, and one perpendicular to the instantaneous velocity.

The component acting tangent to the instantaneous velocity causes angular acceleration. The rate of angular acceleration is proportional to the radial velocity. In the case of the motion presented in the diagram: if the radial velocity is larger then the object is spiralling in at a steeper angle, which means the tangential component (of the centripetal force) is larger, causing larger angular acceleration.