Coriolis force and its impact- UPSC preparation for geography

What do you understand by Coriolis force? Explain the significance of Coriolis force to Earth and some of the atmospheric wind phenomenon. (150 words)

Structure:-

1.     Introduction-Define Coriolis Force

2.    Significance of effects of the Coriolis force.

3.    Examples of atmospheric phenomenon where Coriolis force plays a role.

Answer:-

Coriolis force is an apparent force. Under which Objects moving over the earth's surface across a substantial distance appear to be deflected towards the right in the northern hemisphere and towards the left in the Southern Hemisphere. This is said to be due to the Coriolis force which is considered to be the cause of these deflections. It must be noted that in reality (if seen from the outside the rotating earth), there is no deflection at all and hence no deflecting force in reality.

Because of the rotation of the earth along its axis, the winds are deflected. The force which deflects the direction of winds is called Coriolis force.

Effects seem to be created by Coriolis force:-

1.     It is affected by the wind speed. Hence, higher the wind speed, the higher seem to be the deflection.

2.    It does not affect the wind speed, but only changes the direction of moving wind.

3.    It is zero near the equator(because of the deflection seems to be zero at the equator) and force is strongest at the pole( as the deflection seems to be maximum near the poles)

4.    It is the outcome of the rotation of the earth.

Atmospheric phenomena and Coriolis force:-

1.    Coriolis force and  Cyclones:-

Coriolis force acts as one of the driving forces in the generation of tropical cyclones. Tropical cyclones are the zones of low pressures. When low pressure is generated due to high temperature on a huge water body, then wind from all the surrounding areas come to that region. These winds when move; deflect to the right direction in the northern hemisphere and left in the southern hemisphere under the influence of Coriolis force. This deflection provides the necessary circulation to the low pressure wind system and that is how tropical cyclones move anticlockwise in the northern hemisphere and vice versa. Hence, the Coriolis force plays a critical role in this atmospheric phenomenon.

2.   Coriolis force and Anti- Cyclones:-

Coriolis force acts as a responsible force for the rotation of Anti-cyclones also which is opposite to the cyclonic system. Anti-cyclones are the zones of high pressures. When high pressure is generated due to low temperature, then wind from high-pressure zone diverges to all the surrounding areas. These winds when move; deflect in the right direction in the northern hemisphere and left in the southern hemisphere under the influence of Coriolis force. This deflection provides the necessary circulation to the high-pressure wind system and that is how anti- cyclones move clockwise in the northern hemisphere and vice versa. Hence, Coriolis force plays a critical role in this atmospheric phenomenon.

3.   Easterly and Westerly winds:-

From Sub-tropical high-pressure belts, when wind diverges, Coriolis force acts in a way that winds deflect in the right direction in the Northern hemisphere and vice versa. It leads to the generation of easterly and westerly winds.

Though Coriolis force is an apparent force but it plays a very vital role in global wind patterns and in few very influential atmospheric phenomena such as cyclones and anticyclones.