Abstract
This work concerns the analysis of wave propagation in random media. Our medium of interest is sea ice, which is a composite of a pure ice background and randomly located inclusions of brine and air. From a pulse emitted by a source above the sea ice layer, the main objective of this work is to derive a model for the backscattered signal measured at the source/detector location. The problem is difficult in that, in the practical configuration we consider, the wave impinges on the layer with a non-normal incidence. Since the sea ice is seen by the pulse as an effective (homogenized) medium, the energy is specularly reflected and the backscattered signal vanishes in a first order approximation. What is measured at the detector consists therefore of corrections to leading order terms, and we focus in this work on the homogenization corrector. We describe the propagation by a random Helmholtz equation, and derive an expression of the corrector in this layered framework. We moreover obtain a transport model for quadratic quantities in the random wavefield in a high frequency limit.
Highlights
This work is motivated by the study of electromagnetic wave propagation in sea ice
We have derived in this work, under appropriate conditions on the wavelength, the typical length scale of the fluctuations and their variances, an asymptotic model for the first-order corrector to the homogenization limit
We have considered a simplified model where the inhomogeneities occupy a single layer with flat interfaces, and where the propagation of waves is described by a random Helmholtz equation
Summary
This work is motivated by the study of electromagnetic wave propagation in sea ice. The latter is a formidably complex multiscale material, as a composite of pure ice, brine pockets, and air inclusions of different sizes, shapes, and contrasts. This work is motivated by the study of electromagnetic wave propagation in sea ice. This work is motivated by the study of electromagnetic wave propagation in sea ice The latter is a formidably complex multiscale material, as a composite of pure ice, brine pockets, and air inclusions of different sizes, shapes, and contrasts. Sea ice is often represented as a layered medium, where the volume fraction and the nature of the inclusions vary from layer to layer. Mostly because of the high salt content of brine, and anisotropic due to the particular elongated shape of the brine pockets. Sea ice is modeled by a background (the pure ice), with randomly located inclusions of brine and air with shapes following some appropriate statistical distributions. There is usually a distinction between the young ice that is a few meters thick, and the multi-year ice that can be up to ten meters thick [20]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
