Wavenumber

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Wavenumber in most physical sciences is a wave property usually represented k. It is inversely related to wavelength (usually represented λ). Wavenumber is most frequently defined as:

Less frequently it is defined simply: k = 1 / λ

The wavenumber is closely related to the concept of the wave vector.

Wavenumber in atmospheric science is defined as wavelength divided by the length of the spatial domain, or equivalently the number of times a wave has the same phase over the spatial domain. The domain might be 2π for the non-dimensional case, or

for an atmospheric wave, where R is Earth's radius and φ is latitude.

Wavenumber is the spatial analogue of frequency. Wavenumber and frequency can be obtained from grid point data by application of a Fourier transform in space or time, respectively. In the atmospheric sciences, wavenumber-frequency diagrams are a common way of visualizing atmospheric waves.