Modeling of the electrostatic field generated by horizontal current sources in a sea-ice-covered four-layer medium

The distribution of the underwater electric field around a target in stratified media provides a crucial foundation for research on target detection and localization in marine environments. This paper proposed a four-layer analytical model (air-sea ice-seawater-seabed) to address the issue of electric field propagation in ocean environments involving sea ice. Starting from the Laplace equation for a steady electric field, the repeated image method was employed to introduce image current sources. Combined with the boundary conditions, an analytical solution for the electric field intensity within the seawater layer of the four-layer medium model was derived. Subsequently, a numerical model employing the finite volume method (FVM) was constructed according to the conditions of the experiment and compared with the analytical solutions under the same idealized four-layer conditions. Finally, a scaled-down experiment was designed to compare the measured electric field intensity values with the analytical solutions. The results indicated that the relative error between the measured electric field intensity values and the analytical solutions ranged from 1.17% to a maximum of 11.28%, thus validating the effectiveness of the analytical model and demonstrating its applicability in realistic environments. This work provides the theoretical and technical foundations for detecting underwater targets in the sea-ice-covered marine electromagnetic environment.