Weather Tidbits: The Coriolis Force

We’ll be discussing the coriolis force in this edition of Weather Tidbits. The coriolis force is an apparent force that deflects the path of air or an object due to the rotation of the Earth. Let’s imagine we are looking down at the Earth with two points on it. One closer to the center at a higher latitude, and one further away, closer to the equator. When you spin the Earth all the way around, the equator point will travel more distance than the higher latitude point. If something travels a greater distance in a shorter amount of time, it must go faster. For Earth, that means someone at Greenland will rotate slower than at the equator. From a bird’s eye view, an object traveling from the equator northward will curve to the right as the deflection in the Northern Hemisphere and vice versa. This is because the speed of everything else slows down relative to the object’s movement, which retains its motion via inertia. The same concept goes when moving from the higher latitudes to the equator. This deflection of the path is what causes cyclonic circulations. Low pressure systems circulate counterclockwise in the Northern Hemisphere and clockwise in the southern hemisphere.