Comparative analysis of vertical thermohaline structure of the northwestern tropical Atlantic and Eurasian basin of the Arctic ocean

The CTD data are used to analyze comparatively the properties of temperature and salinity inversions in intrusive layers observed in the northwestern tropical Atlantic and Eurasian Basin of the Arctic (within the depth range of 200-600 m). In both cases the inversions are suggested to be formed by the advective circulations arisen within the quasi-uniform density layers inclined relative to the isopycnic surfaces in a stably stratified medium. An application of the 2D model which had been used before to describe the circulation in the tropical Atlantic layers demonstrated very low estimates of flow velocities and apparent vertical diffusivities in the Arctic layers. This is explained by considerable differences in the Coriolis parameter and in the mean horizontal gradients of temperature and salinity in the frontal zones of two regions of interest. However, if the intrusion Arctic layer circulations are supposed to be three-dimensional (i.e., if there are substantial along-front slopes of layers), the model estimates of circulation velocities and apparent diffusivities based upon 3D approach can be much higher.