Internal waves under the Arctic pack ice during the Arctic Internal Wave Experiment: The coherence structure

The spectral composition of internal gravity waves under the Arctic pack ice during the Arctic Internal Wave Experiment (AIWEX) was found to be strikingly different from observations at lower latitudes. Time series of vertical displacement were inferred from horizontal and vertical arrays of temperature and conductivity sensors. Frequency spectra indicate a whiter spectrum (spectral slope near −1) and a less energetic wave field (by a factor of 0.02) than observations at lower latitude. The analysis of vertical and horizontal coherences revealed a horizontally isotropic wave field that is consistent with assumptions of a random field of linear internal waves. The wavenumber bandwidth of the wave field is about a factor of 10 wider than found at lower latitude.