Compressed sea ice influences wave propagation in a two-layer compressible ocean: Wave blocking and time-domain simulation

Wave propagation in a two-layer compressible ocean covered by a thin, elastic, compressed sea ice is examined by combining the linearized compressible water-wave theory with elastic thin-plate theory. In the gravity- and inertia-dominated regimes demarcated by the ice-thickness-related dimensionless parameter Ka, while the acoustic–gravity wave modes remain strictly monotonic with positive group velocity, the flexural-gravity wave mode undergoes wave blocking (no energy propagation) under high compressive force. We analytically prove and numerically demonstrate that water compressibility shifts the plate buckling threshold away from its incompressible counterpart. The variations of primary and secondary blocking points with applied compression, density ratio, interface depth, and plate thickness are shown along with a comparison with the incompressible counterpart. The system's constituent kinetic, gravitational, compressibility, and plate-associated elastic and inertial components are derived, with the kinetic component being dominant. Time-domain simulations demonstrate forward propagation, stagnation of a portion, and splitting of the wave pulse within the regular, blocking, and instability regimes, respectively, under both interface and surface forcing. These results provide new insight into how stratification, compressibility, and ice-cover mechanics govern wave propagation and energy transfer in realistic oceans.