Skip to main content
Publications | Persons | Institutes | Projects
[ report an error in this record ]basket (0): add | show Print this page

Detailing secondary frontal bore of internal tides breaking above deep-ocean topography
van Haren, H. (2023). Detailing secondary frontal bore of internal tides breaking above deep-ocean topography. J. Oceanogr. 79(6): 581-592. https://dx.doi.org/10.1007/s10872-023-00699-0
In: Journal of Oceanography. Springer: Tokyo; London; Dordrecht; Boston. ISSN 0916-8370; e-ISSN 1573-868X, more
Peer reviewed article  

Available in  Author 

Author keywords
    Steep seamount slope; Mount Josephine NE-Atlantic; 400-m-tall deep-ocean mooring; 200 high-resolution temperature sensors; Secondary bore; Forward breaking

Author  Top 
  • van Haren, H., more

Abstract
    Above steep deep-ocean topography internal tidal waves may break vigorously. The associated turbulent mixing is important for resuspending matter, bringing it tens of meters away from the seafloor for redistribution. While intense turbulence generation occurs around a primary (frontal) bore during each transition from warming downslope to cooling upslope phase of the internal (tidal) carrier wave, a secondary bore can appear about half a wave-period later before the turn to the warming phase. As will be demonstrated from a 100-day mooring array consisting of 200 high-resolution temperature sensors between h = 6–404 m above a steep slope of a large North-Atlantic seamount and a low-resolution acoustic Doppler current profiler sampling between 50 and 450 m, secondary bores show about the same turbulence intensity as around primary bores but they generally show larger overturns that always reach the seafloor. The secondary bores associate with a sudden drop in along-isobath flow speed, a (renewed) increase in upslope flow of up to |0.2| m s−1, and with first-harmonic quarter-diurnal periodicity which provides a spectral peak for turbulence dissipation rate. While each bore is different in appearance, varying from curved like a primary bore to almost straight upward with a ragged bore, secondary bores are in a first approximation forward breaking in contrast with backward breaking primary bores.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Author