Leaky Equatorial Waves

The theory of linear equatorial waves has been established in the 60's, and they have been rigorously studied as essential components for a vast array of equatorial weather phenomena. However, most analytical approaches do not include the physics of energy dissipation due to vertically propagating waves. The abrupt change of the buoyancy frequency at the tropopause leads to the partial trapping of vertically propagating waves in the troposphere, which results in the leaky tropospheric modes, which often form a discrete set, and decay on realistic time-scales. The leaky waves are typically exponential and not sinusoidal, and due to their rapidly varying envelopes the classical dispersive wave theory and the concept of the group velocity does not apply to them. Our recent framework allowed to define the energy propagation speed for exponential waves and generalized the concept of group velocity to the exponential waves, thus allowing for the study of the leaky waves analytically in more detail. In this talk we will show analytical advances on quantifying the physical effects of wave energy leakage on the dynamics of the equatorial waves.