Last updated:

# Coriolis Effect Calculator

What is the Coriolis effect?Coriolis effect definitionCoriolis effect and airplanes

The Coriolis effect causes objects, which should move in a straight line, to deviate from their course. This is an essential phenomenon that affects, for example, the movement of airplanes and missiles. You can use our Coriolis effect calculator to compute the strength of the Coriolis force acting on an object.

• What is the Coriolis effect?
• What is the Coriolis effect definition?
• How does the Coriolis effect influence airplanes?

## What is the Coriolis effect?

The inertial force resulting from the rotational movement of the Earth, which rotates around its own axis from the west to the east, causes the Coriolis effect. As a result, every moving object will be subject to this rotation and thus change the direction of its movement:

• In the northern hemisphere, the direction of a moving body deflects to the right; but
• In the southern hemisphere, the direction of a moving body deflects to the left.

## Coriolis effect definition

We can easily estimate the Coriolis force with the Coriolis effect definition below:

F = 2 × m × v × ω × sin(α)

where:

• F — Coriolis force;
• m — Mass of the moving object;
• v — Velocity of the moving object;
• ωAngular velocity of the Earth; and
• α — Latitude at which the object is located.

Associated Coriolis acceleration equals:

a = F / m = 2 × v × ω × sin(α)

In our Coriolis effect calculator, we assumed that the rotating body is the Earth with angular velocity ω = 2π/24h ≈ 0.0000727 1/s (2π means 360° in radians). Change it if you want to consider some other body.

You can see from the above equation that the magnitude of Coriolis force depends on the latitude at which the object is located. The Coriolis effect is greater near the poles where α = 90° (sin(90°) = 1) and decreases to zero at the equator α = 0° (sin(0°) = 0).

If you would like to learn more about velocity and how to calculate the speed of an object, our velocity calculator is just the tool you need.

## Coriolis effect and airplanes

Do the Coriolis effect and airplanes have something in common? Of course, they have! Let's say that an aircraft (m = 50,000 kg) takes off from London (α = 51.50° N) and travels to North America (to the west) with the velocity v = 500 km/h. With our Coriolis effect calculator, we can compute that this airplane is subjected to the Coriolis force F ≈ 800 N, which means that it deflects to the north with the acceleration a = F / m = 0.016 m/s². It is almost 0.2% of the Earth's gravity! Pilots need to establish a constant force sideways, equal but opposite to the Coriolis force, to compensate for it. It is achieved automatically, by the autopilot, by slightly banking the airplane to keep the heading as planned.

For this example, the banking angle equals only about atan(0.002 × g/g) ≈ 0.115°, so it is too small to be perceivable by passengers. However, without this correction, the airplane may land hundreds or thousands of miles away from the destination point. It is even a possibility that it would fly around the circle, never reaching a final airport!