Publication Date:
2022-05-26
Description:
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 1466–1492, doi:10.1175/JPO-D-12-0154.1.
Description:
Simultaneous full-depth microstructure measurements of turbulence and finestructure measurements of velocity and density are analyzed to investigate the relationship between turbulence and the internal wave field in the Antarctic Circumpolar Current. These data reveal a systematic near-bottom overprediction of the turbulent kinetic energy dissipation rate by finescale parameterization methods in select locations. Sites of near-bottom overprediction are typically characterized by large near-bottom flow speeds and elevated topographic roughness. Further, lower-than-average shear-to-strain ratios indicative of a less near-inertial wave field, rotary spectra suggesting a predominance of upward internal wave energy propagation, and enhanced narrowband variance at vertical wavelengths on the order of 100 m are found at these locations. Finally, finescale overprediction is typically associated with elevated Froude numbers based on the near-bottom shear of the background flow, and a background flow with a systematic backing tendency. Agreement of microstructure- and finestructure-based estimates within the expected uncertainty of the parameterization away from these special sites, the reproducibility of the overprediction signal across various parameterization implementations, and an absence of indications of atypical instrument noise at sites of parameterization overprediction, all suggest that physics not encapsulated by the parameterization play a role in the fate of bottom-generated waves at these locations. Several plausible underpinning mechanisms based on the limited available evidence are discussed that offer guidance for future studies.
Description:
The SOFine project is funded by
the United Kingdom’s Natural Environmental Research
Council (NERC) (Grant NE/G001510/1). SW acknowledges the support
of anARCDiscovery Early CareerResearchAward
(Grant DE120102927), as well as the Grantham Institute
for Climate Change, Imperial College London, and the
ARC Centre of Excellence for Climate System Science
(Grant CE110001028). ACNG acknowledges the support
of a NERC Advanced Research Fellowship (Grant
NE/C517633/1).KLP acknowledges support fromWoods
Hole Oceanographic Institution bridge support funds.
Description:
2014-11-01
Keywords:
Circulation/ Dynamics
;
Diapycnal mixing
;
Internal waves
;
Small scale processes
;
Turbulence
;
Observational techniques and algorithms
;
In situ oceanic observations
;
Profilers, oceanic
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
