Conversion of Love waves in a forest of trees

TL;DR

This paper studies how shear polarized surface waves, similar to Love waves, propagate through a forest of trees, revealing a hybrid wave behavior influenced by tree height and forest structure, with implications for wave control.

Contribution

It introduces the concept of 'Spoof Love' waves, showing how forest structures alter surface wave dispersion and behavior, combining features of spoof plasmons and Love waves.

Findings

Forest acts as an anisotropic wedge with effective boundary conditions.

Hybrid 'Spoof Love' waves can be reflected or converted depending on tree height.

Propagation characteristics depend on the forest's structural variation.

Abstract

We inspect the propagation of shear polarized surface waves akin to Love waves through a forest of trees of same height atop a guiding layer on a soil substrate. We discover that the foliage of trees { brings a radical change in} the nature of the dispersion relation of these surface waves, which behave like spoof plasmons in the limit of a vanishing guiding layer, and like Love waves in the limit of trees with a vanishing height. When we consider a forest with trees of increasing or decreasing height, this hybrid "Spoof Love" wave is either reflected backwards or converted into a downward propagating bulk wave. An asymptotic analysis shows the forest behaves like an anisotropic wedge with effective boundary conditions.