Modeling low-frequency seismo-acoustic propagation in the Arctic using a parabolic equation solution

Abstract

Propagation in Arctic environments is complicated by three-dimensional variations in the waveguide. The sound speed minimum occurs at or near the ice-covered surface, and the upward refracting profile causes long-range propagation to interact repeatedly with the ice cover. Propagation in the Arctic waveguide needs to include an elastic ice cover of variable thickness which may terminate, overlying an ocean layer and an elastic sediment bottom. Parabolic equation solutions are accurate and efficient for elastic layers, although currently, solutions do not exist for Arctic environments. In this paper, elastic parabolic equation solutions will be obtained for range-dependent Arctic waveguides with elastic ice cover and an elastic bottom. Particular interest will be directed to environments where the ice cover terminates. Results will be benchmarked against normal mode and wave number integration solutions.