With reference to “Coriolis force”, which of the following statements is/are correct?
- It increases with increase in wind velocity.
- It is maximum at the poles and is absent at the equator.
Select the answer using the code given below:
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Explanation
Statement 1 is correct
- The rotation of the Earth about its axis affects the direction of the wind. This force is called the Coriolis force. It has a significant impact on the direction of the wind. Due to the earth’s rotation, winds do not cross the isobars at right angles as the pressure gradient force directs, but get deflected from their original path. This deviation is the result of the Earth’s rotation and is called the Coriolis effect or Coriolis force. Due to this effect, winds in the northern hemisphere get deflected to the right of their path and those in the southern hemisphere to their left, following Farrell’s Law (the law that wind is deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, derived from the application of the Coriolis effect to air masses). This deflection force does not seem to exist until the air is set in motion and increases with wind velocity, air mass, and latitude. The Coriolis force acts perpendicular to the pressure gradient force (pressure gradient force is perpendicular to an isobar). As a result of these two forces operating perpendicular to each other, in low-pressure areas, the wind blows around the centre (cyclonic conditions).
Statement 2 is correct
- The Coriolis force is directly proportional to the angle of latitude. It is at a maximum at the poles and absent at the equator. At the equator (Coriolis force is zero), wind blows perpendicular to the isobars. The low-pressure system fills instead of intensifying, i.e., there is no spiralling of air due to the zero Coriolis effect. The winds are directly uplifted vertically to form thunderstorms.
