Characteristic scales and horizontal asymmetry of jet streams in the Earth’s atmosphere

Wind-speed distributions in atmospheric upper air jet streams have a horizontal asymmetry: the wind shear on the northern (cyclonic) side of the jet is larger than that on the southern (anticyclonic) side. The paper suggests an explanation of this feature on the basis of the theory of nonlinear geostrophic adjustment. Simple theoretical estimates are obtained for the asymmetry coefficient of the speed profile. It is shown that the asymmetry increases with the Rossby number (with a jet-stream velocity). Results of the statistical analysis of the horizontal asymmetry of jet streams from Earth’s satellite measurements are described.