  A single-layer model is used to construct the theory of straight-line jets.
In addition to stationary states, the evolution of such jets admits transverse
pulsations. The theory predicts that the period for warm jets pulsations is
longer than the period of inertial oscillations caused by the Earth's rotation,
while for cold jets pulsations, it is shorter. Thus, only warm jets can have a
noticeable effect on the synoptic range of the wind-speed spectrum, generating
into it additional spectral peaks. Within such an approach, every a single jet
is described by a self-similar compactly localized solution that can be
considered as a constant-shear band.
