AI Insight
Researchers used numerical models and theoretical analysis to demonstrate that ocean waves play a more significant role in lateral stirring and mixing of tracers (such as heat, salt, and carbon) than previously understood. Contrary to the traditional view that waves are ineffective at mixing because they primarily transfer energy with minimal fluid displacement, the study shows that internal gravity waves cause irreversible stirring and mixing at spatial scales below 10 kilometers. The findings reveal that wave amplitude directly affects the structural complexity of tracer distributions in the ocean.
Why it matters
This research addresses critical gaps in ocean modeling accuracy, particularly for predicting tracer dispersion at small scales. Improved understanding of wave-driven mixing could reduce biases in large-scale ocean climate models and enhance predictions of ocean climate variability, which is essential for climate change projections and carbon cycle assessments.
Understand the Science
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances
Ocean waves originate from a movement of energy, with limited displacement of fluid particles along the main wave direction. For this reason, they are often thought to be ineffective in stirring and mixing of oceanic tracers like heat, salt, carbon and others. However, recent observations of tracer dispersion at spatial scale lower than 10 km highlighted the urgency of gaining an improved understanding of the role of waves to determine dispersion of passive tracers.
Using numerical models and theoretical considerations, Sanjay and Thomas [2026] look at how waves affect the movement of tracers in wave-rich environments. They find that wave effects are more important for lateral stirring and mixing than was previously thought. The results suggest solutions to improve the accuracy of large-scale ocean models, therefore reducing tracer modeling biases, and ultimately improving predictions of ocean climate variability.
Citation: Sanjay, C. P., & Thomas, J. (2026). Irreversible stirring and mixing of tracers by oceanic internal gravity waves. AGU Advances, 7, e2026AV002429. https://doi.org/10.1029/2026AV002429
—Alberto Montanari, Editor-in-Chief, AGU Advances
Text © 2026. The authors. CC BY-NC-ND 3.0
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Source: Waves Play a Key Role for Lateral Stirring and Mixing of Ocean Tracers