What is Coriolis effect?
The rotation of the earth about its axis affects the direction of the wind. If the Earth did not rotate and remained stationary, the atmosphere would circulate between the poles (high pressure areas) and the equator (a low pressure area) in a simple back-and-forth pattern.
But because the Earth rotates, circulating air is deflected. Instead of circulating in a straight pattern, the air deflects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths. This deflection is called the Coriolis effect.
It is named after the French mathematician and physicist Gaspard Gustave de Coriolis who described it in 1844.
How Coriolis force varies on Earth?
Coriolis force increases with increase in wind velocity. Thus, the deflection in circulating air is more when the wind velocity is high.
The Coriolis force is directly proportional to the angle of latitude. Thus, Coriolis force is maximum at the poles and is absent at the equator.
How Coriolis force helps in formation of cyclones?
The Coriolis force acts perpendicular to the pressure gradient force.
The pressure gradient force is perpendicular to an isobar.
The higher the pressure gradient force, the more is the velocity of the wind and the larger is the deflection in the direction of wind.
As a result of these two forces operating perpendicular to each other, in the low-pressure areas the wind blows around it and cyclone is formed.
Why tropical cyclones are not formed near the equator?
At the equator, the Coriolis force is zero and the wind blows perpendicular to the isobars. The low pressure gets filled instead of getting intensified. That is the reason why tropical cyclones are not formed near the equator.
For further information : External link: https://en.wikipedia.org/wiki/Coriolis_force
PRACTICE QUESTIONS
QUES . With reference to “Coriolis force”, which of the following statements is/are correct? UPSC 2024
1 . It increases with increase in wind velocity.
2 . It is maximum at the poles and is absent at the equator.
Select the answer using the code given below:
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans (c)
