We propose an approach to quantify energy barriers to the vertical movement (upward-downward) of water parcels in diverse aquatic bodies, which are associated with the vertical variation in density (stratification). The approach analyzes these barriers in detail and provides an objective measure of stratification intensity in any vertical section of the water column. This approach can enhance our understanding of the effects of stratification on diverse ocean-atmosphere interaction processes.

The surface mixed layer depth (MLD), where ocean properties are uniform, is key to ocean-atmosphere interactions and ocean dynamics. We propose an energy-based method that defines the MLD using a constant value of buoyancy work that accurately captures the upper ocean's well-mixed layer. This approach is globally and temporally consistent and reliable, improving MLD estimates, aiding ocean model validation, and advancing studies of ocean heat content and vertical exchanges.

In this study, we present a methodology to locate the minimum and maximum depths of the strongest thermocline, its thickness, and its strength by adjusting the sigmoid function to the temperature profiles in the global ocean. The results of the methodology are compared with the results of other methods found in the literature, and an assessment of the ocean regions where the adjustment is valid is provided. The method proposed here has shown to be robust and easy to apply.