nieuwe zoekopdracht
[ meld een fout in dit record ]mandje (0): toevoegen | toon Print deze pagina

Abyssal plain hills and internal wave turbulence
van Haren, H. (2018). Abyssal plain hills and internal wave turbulence. Biogeosciences 15(14): 4387-4403. https://doi.org/10.5194/bg-15-4387-2018

Bijhorende info:
In: Gattuso, J.P.; Kesselmeier, J. (Ed.) Biogeosciences. Copernicus Publications: Göttingen. ISSN 1726-4170; e-ISSN 1726-4189, meer
Peer reviewed article  

Beschikbaar in  Auteur 

Auteur  Top 
  • van Haren, H., meer

Abstract
    400m long array with 201 high-resolution NIOZ temperature sensors was deployed above a north-east equatorial Pacific hilly abyssal plain for 2.5 months. The sensors sampled at a rate of 1Hz. The lowest sensor was at 7m above the bottom (ma.b.). The aim was to study internal waves and turbulent overturning away from large-scale ocean topography. Topography consisted of moderately elevated hills (a few hundred metres), providing a mean bottom slope of one-third of that found at the Mid-Atlantic Ridge (on 2km horizontal scales). In contrast with observations over large-scale topography like guyots, ridges and continental slopes, the present data showed a well-defined near-homogeneous bottom boundary layer. However, its thickness varied strongly with time between  < 7 and 100ma.b. with a mean around 65ma.b. The average thickness exceeded tidal current bottom-frictional heights so that internal wave breaking dominated over bottom friction. Near-bottom fronts also varied in time (and thus space). Occasional coupling was observed between the interior internal wave breaking and the near-bottom overturning, with varying up- and down- phase propagation. In contrast with currents that were dominated by the semidiurnal tide, 200m shear was dominant at (sub-)inertial frequencies. The shear was so large that it provided a background of marginal stability for the straining high-frequency internal wave field in the interior. Daily averaged turbulence dissipation rate estimates were between 10−10 and 10−9m2s−3, increasing with depth, while eddy diffusivities were of the order of 10−4m2s−1. This most intense near-bottom internal-wave-induced turbulence will affect the resuspension of sediments.

Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid Top | Auteur 
IMIS is ontwikkeld en wordt gehost door het VLIZ, voor meer informatie contacteer .