What is the Coriolis Effect?

Coriolis effect If an object is stationary or moves at a constant speed relative to a fixed point, then there will be no problem in moving on this object. If you want to walk along a straight line from point A at one end of the object to point B at the other end, you will not feel any difficulty in the process.

Coriolis effect

Coriolis effect If an object is stationary or moves at a constant speed relative to a fixed point, then there will be no problem in moving on this object. If you want to walk along a straight line from point A at one end of the object to point B at the other end, you will not feel any difficulty in the process. However, if different parts of an object move at different speeds, the situation is quite different. Suppose there is a rotating table or any platform that rotates around its center. The whole platform is rotating, but a small circle is drawn at a point near the center, so it is moving slowly, and a large circle is drawn at a point near the outer edge, so it is moving quickly.

Suppose you are standing at the point near the center and want to go straight from the center to the outer edge

The most significant significance of the Coriolis effect in daily life is related to the rotating earth.

The following introduces some phenomena formed in the real life under the influence of Coriolis forces: China is located in the northern hemisphere. Objects move on the ground and are deflected to the right by the force of ground turning. This phenomenon has never been seen in daily life. observed. When people walk, they never unknowingly turn to the right. This is entirely because the deflection force of ground rotation is very small, and its effect is masked by the effects of other forces. The effect of the geostrophic bias force is easy to detect only under the condition of long-term accumulation.

The Coriolis effect can explain the following phenomena and theories:

1. Bower's Law: This law is a well-known law in natural geography that is summarized from actual observations, that is, the river is sharper near the equator. This can be explained by the geostrophic biasing force. Under the action of the geostrophic biasing force, river water scours one bank closer to the equator than the other. As a result of long-term accumulation, the bank near the equator is relatively steep.

2. Atmospheric circulation: The energy of atmospheric motion is derived from solar radiation, and the pressure force of atmospheric pressure is the source of atmospheric motion. There are seven atmospheric pressure zones in the world, including the equatorial low pressure zone, the subtropical high pressure zone near the latitude 30 ° in the southern and northern hemispheres, the subpolar low pressure zone near the latitude 60 ° in the southern and northern hemispheres, and the polar high pressure zone in the southern and northern hemispheres. Low pressure latitudes, middle latitudes, and high latitudes are formed between the pressure bands under the effect of pressure gradient forces and geostrophic bias forces. Due to the deflection force of the ground rotation, the north-south airflow deflected from east to west. The airflow from north to south near the ground in the northern hemisphere has a westward deflection. Six wind bands are formed between the pressure bands, namely the low latitude trade winds in the southern and northern hemispheres, the middle latitude westerly winds in the southern and northern hemispheres, and the polar east winds in the southern and northern hemispheres.

3. Cyclones and anticyclones: Cyclones and anticyclones are the most common forms of motion in the atmosphere, and they are also important weather systems that affect weather changes. Under the combined effect of the pressure gradient force and the geostrophic deflection force, the atmosphere does not flow directly at the center of the low pressure, nor does it flow out from the center of the high pressure along the radiation direction. The low-pressure airflow deflected to the right in the northern hemisphere into a large vortex flowing in a clockwise direction, and turned to the left in the southern hemisphere into a large vortex flowing in a counterclockwise direction. This atmospheric flow is very similar to the vortex of water in river currents, so Called cyclone. In summer and autumn, typhoons that often appear on the southeast coast of China are a form of the strong development of tropical cyclones. The high-pressure airflow rotates out in the clockwise direction in the northern hemisphere and rotates in the counterclockwise direction in the southern hemisphere. This high-pressure circulation system is called anticyclone.

4. Foucault pendulum: The rotation of the earth will also affect the movement of the pendulum, and the vibration plane of the pendulum will continue to deflect in a clockwise direction. In the church of Paris in 1851, Foucault used a pendulum with a length of 67m. The pendulum ball was an iron ball with a diameter slightly larger than 30cm. A single pendulum with a total mass of 28kg verified the rotation of the earth. When the single pendulum vibrates, the long axis of the circle is equal to 3m, the period of vibration of the pendulum is 16s, and the period of rotation with the circle is 32h. For the first time in history, Foucault verified the rotation of the earth.

5. Double-track trains: China is located in the northern hemisphere. Trains are subjected to ground deflection forces during driving, so the pressure on the right rail is greater than the pressure on the left rail. Ordinary monorail trains often run in opposite directions. The two rails wear almost the same. Due to the influence of the history of train development, the traffic signals used by dispatchers to instruct trains to start, stop, and not allow pit stops are set on the left side of the train's forward direction, so double-track trains are left. Due to the ground turning biasing force pointing to the right of the train, the ground turning biasing forces of the trains that go left on the double-track railway are directed inward. Let a train with a mass of 2000t, a speed of 20m / s, the latitude of the train location be 45 °, and the horizontal component of the ground turning bias force FC _level = 2mVsin45 ° = 4123N, which is equivalent to only two ten thousandths of the train s dead weight Only a few percent of the resistance to trains. A force of this magnitude can only show that the right rail wears a lot, without causing two trains running on the double line to collide.