Cause of horizontal tilt differences between mooring lines

Determine precisely what causes the observed tilt differences between closely spaced mooring lines in the deep Northwestern Mediterranean, including the roles of line wakes, buoy geometry, and other small-scale flow processes.

Background

The study observes substantial tilt differences between mooring lines separated by approximately 9.5 m, with variations that sometimes correspond to relative-vorticity conditions. The author argues that wakes generated by the vertical lines and buoys should produce only weak turbulence and that vortex shedding is not expected at the relevant scales. Consequently, the physical mechanism producing the measured tilt differences remains unresolved.

References

However, it is unclear what precisely causes the tilt differences, as the wakes from the vertical lines are expected to induce relatively weak turbulence due to the small diameters of line and buoy so that vortex shedding is not expected to be noticeable over scales O(0.01) m for the line and O(1) m for the buoy.

— Short spatial mooring-tilt variations from deep Mediterranean observations  (2608.21046 - Haren, 21 Aug 2026) in Section 3, page 8

Except for an unknown sub-peak at 0.5 cpd, its spectral slope in the sub-inertial, sub-mesoscale frequency range matches p = −7/5, is significantly different from that of tilt and kinetic energy, and complies with the BO-model for active scalars (and which thus have a different slope from that of the associated advective-flow kinetic energy).

— Short spatial mooring-tilt variations from deep Mediterranean observations  (2608.21046 - Haren, 21 Aug 2026) in Section 3, page 9