Visualization showing differences between the Lagrangian specification and the Eulerian specification
Differences between the Lagrangian specification (the observer moves along with the seawater parcel) and the Eulerian specification (the observer stands at a fixed point). Black contours denote the sea surface height with an interval of 1 cm. Red contours denote ocean eddy detected in the Eulerian specification. Blue shades denote the ocean eddy detected in the Lagrangian specification. Credit: Liu et al. [2019], Figure 3
Source: Journal of Geophysical Research: Oceans

Eddies, which are relatively small swirls of water that can travel long distances, play an important role in the transport of heat, nutrients, salt and other chemicals in the global ocean. Using principles of fluid dynamics, most studies of mass transport by ocean eddies apply the Eulerian specification, where the observer collects data from a fixed point as the water flows by.

However, Liu et al. [2019] also apply the Lagrangian specification, where the observer collects data while traveling along with the moving water parcel. Their comparison finds that both the directions and quantities of ocean transport can be significantly different depending on the specification used. Therefore, the global energy distribution and nutrient spread, which are closely related to the eddy transport deserve a careful revisit, as significantly different estimates may be expected.

Citation: Liu, T., Abernathey, R., Sinha, A., & Chen, D. [2019]. Quantifying eulerian eddy leakiness in an idealized model. Journal of Geophysical Research: Oceans, 124.

—Lei Zhou, Editor, JGR: Oceans

Text © 2019. The authors. CC BY-NC-ND 3.0
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