Spectra of Deep Vertical Temperature Profiles

Abstract

Repeated temperature profiles were obtained at a slowly sinking and rising free float in a depth range of 1300 to 3600 m at 10°24?N, 50°22?W during the period 15?17 October 1967. Temperature deviations from a linear gradient had spectra with approximately a ?2 power dependence on wavenumber over a range of 5 m to a few hundred meters; a ?5/3 power dependency is not excluded. No significant coherence was obtained between successive profiles even though some were scanned a few hours later at the same location. Spectra of the ratio of temperature deviation from a linear gradient to the average temperature gradient over different depth intervals at this as well as two other distant locations are similar in slope and in magnitude. The standard deviations of temperature from a linear profile were found to be comparable with the deviations measured at free hovering floats at three locations.