Towed Observations of Internal Waves in the Upper Ocean

摘要

Observations between 20 and 40 m depth were made with a towed thermister chain in the North Pacific. Despite the rapid vertical variation of buoyancy frequency, spectra of isotherm displacements are in fair agreement with other observations and with the Garrett-Munk model. The spectra show evidence of a shoulder and break in slope at a wavelength of 1 km. There is no evidence of significant variation of spectral levels as a function of buoyancy frequency, tow direction or wind speed. A peak at a wavelength of 1 km in coherence spectra between pairs of isotherms separated in the vertical suggests that internal wave energy at this wavelength is dominated by the low modes. (Author)