Oceanography The Official Magazine of
The Oceanography Society
Volume 28 Issue 01

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Volume 28, No. 1
Pages 142 - 149

Three-Dimensional Dynamics of Freshwater Lenses in the Ocean’s Near-Surface Layer

Alexander V. Soloviev Silvia Matt Atsushi Fujimura
Article Abstract

Convective rains in the Intertropical Convergence Zone produce lenses of freshened water on the ocean surface. Due to significant density differences between the freshened and saltier seawater, strong pressure gradients develop, resulting in lateral spreading of freshwater lenses in the form of gravity currents. Gravity currents inherently involve three-dimensional dynamics. As a type of organized structure, gravity currents may also interact with, and be shaped by, the ambient oceanic and atmospheric environment. Among the important environmental factors are background stratification and wind stress. Under certain conditions, a resonant interaction between a propagating freshwater lens and internal waves in the underlying halocline (the barrier layer) may develop, while interaction with the wind stress may produce an asymmetry in the freshwater lens and associated mixing. These two types of interactions working in concert may explain the series of sharp frontal interfaces observed in association with freshwater lenses during the Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE). We conducted a series of numerical simulations using computational fluid dynamics tools. These numerical experiments were designed to elucidate the relationship between vertical and horizontal fluxes of salinity under various environmental conditions and the potential impact of these fluxes on the barrier layer and Aquarius and Soil Moisture and Ocean Salinity (SMOS) satellite image formations.

Citation

Soloviev, A.V., S. Matt, and A. Fujimura. 2015. Three-dimensional dynamics of fresh​water lenses in the ocean’s near-surface layer. Oceanography 28(1):142–149, https://doi.org/10.5670/oceanog.2015.14.

Supplementary Materials

Animation of the evolution of the freshwater plume interacting with wind stress. 
Available in two formats:
• 86 KB mp4 video
• 410 KB wmv video

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