Acoustic EM-Apex: subsurface tracking and iso-surface sampling of density, velocity, and turbulence to resolve Lagrangian submesoscale dynamics
Abstract
Approved for Public ReleaseThis project will add acoustic tracking and acoustic communication to an existing velocity profiling float, the EM-Apex. The resulting float will be capable of measuring profiles of CTD, velocity, and microstructure, and receiving and transmitting mid-frequency acoustic signals for localization and data transmission. Sampling modes will be developed to take advantage of acoustic tracking and transmissions, including prolonged tracking at depth while following a selected iso-surface and performing short profiles bracketing the target surface. The acoustic hardware, its capabilities, and the associated sampling modes will be coordinated to be inter-operable with other RIOT projects. Testing and refining successful operational modes for subsurface networks is an integral part of being able to use the new capabilities. The resulting coordinated and heterogeneous subsurface networks of floats, gliders, and other vehicles will be more capable than any one constituent vehicle, with the added benefit of flexible deployment configurations.With the new capabilities of an acoustic EM-Apex, a host of scientific questions become tractable that require co-located sampling of density, velocity, turbulence, and their vertical and and horizontal gradients. By performing short profiles around the iso-surface, we exchange exact 2D-Lagrangian behavior for the powerful ability to resolve vertical structure. Vertical stratification and shear is essential for most processes operating at the interior submesoscale -turbulence, internal waves, vortex stirring, critical layers. Unlike in the surface mixed layer, though, where time scales are driven by atmospheric forcing, the subsurfaceis isolated from direct forcing and so the longevity of float measurements is well matched to the evolution of these phenomena. Potential uses of an array of these floats will be to sample an energetic turbulent layer ( e.g. a separated seamount wake) for 1-2 weeks, or the evolutionof the core of a water-mass for multiple months.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2024
- Source ID
- N000142412724
Entities
People
- Zoltan Szuts
Organizations
- Office of Naval Research
- United States Navy
- University of Washington