Coriolis effect: one construct, many systems

In physical oceanography the Coriolis effect is the apparent sideways force, arising because the ocean sits on a rotating planet, that deflects moving water to the right in the Northern Hemisphere and to the left in the Southern, shaping currents, gyres, and the Ekman spiral. Gill's Atmosphere–ocean dynamics develops it through the Coriolis parameter and its central role in geostrophic and inertial motion of the sea. It is exactly the same inertial deflection that acts on the wind and on a mass in a spinning laboratory, here expressed in seawater and measured by the same latitude-dependent parameter.[1]

Unit

The Coriolis acceleration on moving water (set by the Coriolis parameter)

Recovery means

Not applicable

Measured by

Expressed through the Coriolis parameter f = 2Ω sin φ and seen in geostrophic current balance, Ekman transport, and inertial oscillations

In meteorology the Coriolis effect is the same rotation-induced deflection acting on the air, turning winds to the right in the Northern Hemisphere and to the left in the Southern, which is why large-scale flow curves around pressure systems rather than rushing straight toward low pressure. Persson's 1998 How do we understand the Coriolis force? traces the concept and clears up the confusions that surround it. It is the identical inertial force as in the ocean or a rotating lab, realised in the atmosphere and underlying the geostrophic balance that governs synoptic winds.[2]

Unit

The Coriolis acceleration on moving air (set by the Coriolis parameter)

Recovery means

Not applicable

Measured by

Expressed through the Coriolis parameter f = 2Ω sin φ and seen in geostrophic and gradient wind balance and inertial motion

In classical mechanics the Coriolis force is one of the fictitious (inertial) forces that appear when motion is described in a rotating reference frame: it acts perpendicular to the velocity, is proportional to the velocity and to the frame's rotation rate, and vanishes in an inertial frame. Goldstein, Poole, and Safko's Classical mechanics derives it from the transformation to a rotating frame, where it sits alongside the centrifugal term. This is the root construct (the same term that, applied to a rotating planet, deflects winds and ocean currents), defined here as a general consequence of describing motion in a spinning frame rather than as a weather or ocean phenomenon.[3]

Unit

The inertial acceleration in a rotating frame (proportional to twice the rotation rate times velocity)

Recovery means

Not applicable

Measured by

Given by the term −2Ω × v in the equation of motion written in a rotating reference frame