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Coriolis Force and Coriolis Effect, Causes, Impacts, Diagram

Coriolis force and Coriolis effect are crucial in understanding the dynamics of fluid motion on Earth, affecting weather patterns, ocean currents, and even the trajectory of projectiles. They are manifestations of the Earth’s rotation influencing the behavior of objects and fluids moving across its surface.

Coriolis Force

The Coriolis force, which is caused by the earth’s rotation about its axis, influences the wind’s direction. It is inversely proportional to the latitude angle. In the southern hemisphere, it deflects the wind to the left, and in the northern hemisphere, it is to the right.

Coriolis force Overview
Definition The Coriolis force is a fictitious force that appears to act on objects moving within a rotating reference frame, such as the Earth.
Cause Arises due to the rotation of the Earth. As objects move across the rotating Earth, they appear to be deflected from their straight-line path.
Direction Deflects moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.
Formula Fc=−2m(Ω×v)\mathbf{F}_c = -2m (\mathbf{\Omega} \times \mathbf{v}), where Fc\mathbf{F}_c is the Coriolis force, mm is the mass of the object, Ω\mathbf{\Omega} is the angular velocity vector of the rotating frame, and v\mathbf{v} is the velocity of the object relative to the rotating frame.
Applications Influences the movement of air masses, ocean currents, and trajectories of projectiles.

Coriolis Force and Coriolis Effect

Any object moving freely near Earth’s surface appears to deflect to the right in the Northern Hemisphere and to its left in the Southern Hemisphere due to the earth’s rotation. The following are significant aspects of the Coriolis Effect:

  • The apparent deflection is greatest at the poles and gradually decreases toward the equator, where it is zero.
  • The Coriolis effect is proportional to the object’s speed. Thus, a fast-moving object is deflected more than a slower one.
  • The Coriolis effect decides the direction of movement only and does not change the speed of an object. Thus, it affects the direction of wind flow.
  • The Coriolis effect deflection acts at right angles from the direction of movement. Thus, the Coriolis effect keeps the wind from directly following the pressure gradient force.

If these two factors are in balance, as in the upper atmosphere, the wind moves parallel to the isobars. It is called geostrophic wind. Most winds in the atmosphere are geostrophic or nearly geostrophic. This is because they flow nearly parallel to the isobars. Only near the surface, the frictional force further complicates the situation.

Read More: Atmospheric Circulation

Coriolis Force Diagram

The wind’s direction is influenced by the Coriolis Force, which is caused by the earth’s rotation of its axis. An illustration of Coriolis Force and Effect is below.


Read More: Types of Winds

Coriolis Effect Causes

The Coriolis Effect is primarily caused by the earth’s rotation. When the earth rotates anticlockwise on its axis, everything flying or flowing at a considerable distance above the planet’s surface appears to be deflected. This occurs when the earth moves east more quickly beneath an object that is moving freely above the surface of the planet.

As latitude rises and the earth’s rotation slows, the Coriolis effect intensifies. A plane travelling in a straight line parallel to the equator would be able to retain its location with no discernible movement. A small deviation north or south of the equator would occur for the aircraft. In addition to the earth’s rotational speed and latitude, there will be more deflection the faster the item goes.

Read More: Pressure Belts

Coriolis Force Impacts

  • The Coriolis effect has an impact on almost all fields that study planetary motions and Earth motions.
  • It is essential to atmospheric dynamics, such as wind and storm motions.
  • Oceanography, explains how ocean currents move. One of the most important geographical impacts of the Coriolis effect is the deflection of winds and Ocean Currents.
  • It also affects manufactured items like planes and missiles.
  • The Coriolis effect affects nearly all sciences that study planetary and Earth motions.
  • The dynamics of the atmosphere, including wind and storm motions, depend on the Coriolis Force.

Read More: List of Major Local Winds

Coriolis Force and Coriolis Effect UPSC

The wind always blows from high pressure to low pressure. The Coriolis force is the force exerted by the earth’s rotation that deflects wind movement. Wind movement is also influenced by friction caused by various relief features on the soil. The wind, for example, blows faster and in the same direction over maritime surfaces; however, the presence of mountains or valleys on land influences the wind’s direction and speed. These notes will also be useful for other competitive exams such as UPSC. This article discusses the Coriolis Effect, its causes, and its significance.

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What is Coriolis force?

The earth spins around its axis, producing a force known as the Coriolis force.

How does the Coriolis effect affect wind movement?

The Coriolis force causes the wind to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere.

What is an example of the Coriolis effect?

A cyclone is produced as a result of the rotation of a massive mass of air at the centre and is the most notable effect of the Coriolis force on the earth. The air is forced from a warm low-pressure region to a damp high-pressure region, which causes cyclones. The air draws toward the centre as the air mass spins.

What is Coriolis effect and how does it effect wind?

We perceive the Coriolis force, an apparent force caused by the rotation of the Earth.This causes the wind to be deflected to the right in the northern hemisphere and to the left in the southern hemisphere.

What causes the Coriolis effect to be zero at the equator?

The path of an object moving horizontally and freely at the equator does not curve relative to the Earth's surface because there is no sensation of rotation of the Earth's surface underneath it.Because the object's trajectory is straight, there is no Coriolis effect.

Why Coriolis force is maximum at the poles?

The twisting of the underlying Earth's surface caused by the planet's rotation increases as the latitude at which horizontally and freely moving objects are located increases. That is, as latitude increases, so does the Coriolis effect. It is greatest at the poles and completely absent at the equator.


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