Recent research led by Joseph Skitka from the Department of Earth and Environmental Sciences at the University of Michigan has shed light on the mechanisms behind internal wave dissipation in ocean models. Published in the journal “Geophysical Research Letters,” this study highlights the significance of internal waves (IWs) in contributing to ocean mixing, a critical process for marine ecosystems and climate regulation.
Internal waves are oscillations that occur within the ocean’s interior, often caused by tides or wind. These waves can dissipate energy, leading to mixing that affects temperature, salinity, and nutrient distribution in the water column. Understanding how these waves dissipate is vital for accurately modeling ocean dynamics, which has implications for various sectors, including fisheries, climate forecasting, and renewable energy.
Skitka’s research introduces a novel horizontal viscosity scheme that selectively targets horizontally rotational modes, like eddies, which could enhance the accuracy of ocean models. The findings suggest that when this restricted form of horizontal viscosity is incorporated into global models with similar resolutions, it could significantly improve the diagnosis and mapping of internal wave dissipation distributions.
At lower resolutions with grid spacings of 2 km, the modeled internal wave dissipation aligns reasonably well with observational data, indicating that this approach holds promise for refining ocean models used in commercial applications. However, at higher resolutions of around 250 m, the study found that the combined effects of vertical shear and horizontal viscosity led to overestimations of dissipation. Despite this, the vertical-shear dissipation estimates closely matched observations, suggesting that fine-tuning these models could yield more reliable results.
This research has commercial implications, particularly for industries reliant on accurate oceanographic data. For instance, fisheries management could benefit from improved models that predict nutrient distribution and fish migration patterns, while offshore renewable energy projects, such as wind and tidal energy, could utilize enhanced ocean models to optimize site selection and infrastructure design.
As Skitka notes, “the possibility that if restricted forms of horizontal viscosity are adopted by global models with similar resolutions, they could be used to diagnose and map IW dissipation distributions” opens new avenues for both scientific inquiry and practical application in ocean-related sectors. This study not only contributes to our understanding of ocean dynamics but also presents opportunities for advancements in technology and resource management.
