Does the earth's rotation affect climate?

1 Answer
May 5, 2016



My initial thought was that the Earth's rotation only causes night and day and therefore had no real impact on climate. Then I thought a bit more and realized that Earth's rotation might be the most important thing in establishing climate.

You see I had forgotten about the Coriolis effect.

The Coriolis effect is an apparent force caused by the rotation of the Earth. This effect deflects winds in the same way that drawing a straight line on a rotating piece of paper. You move your pen straight but the line is curved.

The reason that has such a huge effect on climate is that without Coriolis there would be no high or low pressures centers, just a uniform pressure.

Air wants to flow from areas of high pressure to areas of low pressure, which just makes sense. The thing is, if there was no outside effect then the pressure gradient cause by the different pressures would result in a pressure gradient force. This force moves the air from high pressure to low pressure. However, as the air is moving the Earth is also rotating. This causes the air to deflect so that it slowly rotates around and inward toward a low and around and outward from a high. As such low pressures are not immediately filled and pressures do not easily balance out.

Without Coriolis wind would be unidirectional, heat would advect quickly and there would be nearly uniform pressure around the world. Deserts would get rain as there would be no Hadley cells. Rainforests would get less rain as the systems simply wouldn't form and precipitation would be close to uniform around the globe.