A classic problem of propagation of linear wave packets in dispersive media is considered. Asymptotics of the Cauchy problem for two-dimensional gaussian wave packets are found in terms of Fourier integrals. These asymptotic solutions are regular at caustics and describe new physical effects of the packet propagation: rotation in space and formation of wave front which dispersion appears to be anomalously slow as compared to the well-known solutions for dispersive waves.
92.10.H- Ocean waves and oscillations
92.10.hf Planetary waves, Rossby waves
$^1$P.P. Shirshov Institute of Oceanology RAS
$^2$Novosibirsk State University