beta plane

The name 'beta plane' derives from the convention to denote the linear coefficient of variation with the Greek letter β.

This equatorial Beta plane assumption requires a geostrophic balance between the eastward velocity and the north-south pressure gradient.

In analogy with the f-plane, this approximation is termed the beta plane, even though it no longer describes dynamics on a hypothetical tangent plane.

Because these waves are equatorial, the Coriolis parameter vanishes at 0 degrees; therefore, it is necessary to use the equatorial beta plane approximation that states:

In geophysical fluid dynamics, an approximation whereby the Coriolis parameter, f, is set to vary linearly in space is called a beta plane approximation.

The advantage of the beta plane approximation over more accurate formulations is that it does not contribute nonlinear terms to the dynamical equations; such terms make the equations harder to solve.

In Planetary waves on beta planes, he developed a beta plane approximation for simplifying the equations of classical tidal theory, whilst at the same time developing planetary wave relations.

The beta plane approximation is useful for the theoretical analysis of many phenomena in geophysical fluid dynamics since it makes the equations much more tractable, yet retains the important information that the Coriolis parameter varies in space.

Equatorial Rossby waves, often called planetary waves, are very long, low frequency waves found near the equator and are derived using the equatorial Beta plane approximation, , where "β" is the variation of the Coriolis parameter with latitude, .