Enhanced Gliders for Routine Turbulence Measurements
Abstract
Lateral mixing is driven through the interplay between fine-scale isopycnal stirring (shear and strain) and small-scale diapycnal turbulence. We seek to understand this interplay within highly anisotropic coherent structures, such as fronts, jets, eddies, and filaments, which likely control lateral dispersion in both coastal and open ocean. These structures evolve yet are often persistent on O (3 day) time scales, so they are ideally suited to be adaptively sampled by autonomous gliders that actively report both turbulent and fine-scale statistics. As part of a coordinated effort to quantify the meso-scale through micro-scale processes driving lateral dispersion, we plan to deploy 4 AUV gliders to perform intensive, adaptive surveys. Newly enhanced to measure turbulent mixing, water-column currents, and dye concentration, these autonomous gliders will capture the interplay among shear, strain, and turbulence over a wide range of scales. In conjunction with ship-based dye release experiments, adaptive glider sampling will substantially increase the synoptic coverage of the dye surveys, providing a more complete description of the spread and dispersion of the dye. Microstructure sensors will allow for the quantification of small-scale mixing and its dynamical feedback to meso and sub-mesoscale flows. ADCP imaging of water column velocity will do the following: (1) characterize the features driving fluid dispersion, (2) help build better turbulence parameterizations in anisotropic environments, and (3) provide enhanced tracking capabilities for lateral coherence calculations. The scarcity of synoptic observations in the past has made it impossible to detangle the lateral and vertical processes. Adaptive sampling with multiple gliders in multiple locations for extended durations will provide the detailed statistics necessary for the community to make progress.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2009
- Accession Number
- ADA527041
Entities
People
- James N. Moum
- John A. Barth
- Jonathan D. Nash
- R. K. Shearman
Organizations
- Oregon State University