Isolating the magnetic signature of internal waves

Internal waves in the ocean environment produce weak magnetic fields through induction as seawater is conductive. The induced field can be detected in measurements of the magnetic field using a sensitive magnetometer. Isolating the magnetic signature of these ubiquitous phenomena from geomagnetic and noise sources requires careful analysis. The experiment uses two fixed bottom mounted magnetometers, one on shore and the other underwater, and an underwater bottom mounted acoustic Doppler current profiler (ADCP). Raw signals are adjusted for any data corruption and anthropomorphic interference, such as large spike removal through Anderson functions. Wavelet decomposition is used to automatically detect spikes in the magnetic data and allows for their replacement through interpolation schemes. Then filtering techniques, including frequency-domain cancellation (FDC), are used to show the signature of the internal wave. These results are correlated with ADCP data to search for internal wave activity.