Magnetic noise associated with ocean internal waves

Environmental noise can be a major limitation on the performance of magnetic sensor systems in continental shelf regions. Previous work has predicted the magnetic influence from internal waves and indicates that these could be important components of ambient ocean magnetic noise. Existing electric and magnetic field sensor technology has an instrument noise floor well below the ambient magnetic noise in shallow water applications. Model predictions indicate that internal oceanographic features, such as high amplitude internal waves, internal bores and solitary waves, can contribute magnetic variations in the very low frequency band ranging from 0.1 to 1.0 nT which is well above the noise level of commercial magnetometer systems. Predictions of the magnetic character for internal ocean dynamics are computed using a nested non-hydrostatic ocean model coupled with a simple electromagnetic model. These predictions should correlate with oceanographic observations of water velocity. Comparison of the model predictions with observed oceanographic measurements is under investigation.