# Angular wavenumber

From AMS Glossary

## angular wavenumber

(

*Also called*azimuthal wavenumber, hemispheric wavenumber, zonal wavenumber.) In many meteorological contexts, the number of waves of a given wavelength required to encircle the earth at the latitude of the disturbance. If*L*is the wavelength,*r*the earth's radius, and φ the geographical latitude, the angular wavenumber*k*is given by*k*= 2π*r*cos φ/*L*.