The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean
Name
Nikurashin-2014-The Impact of Finite.pdf
Size
2.76 MB
Format
Adobe PDF
Checksum (MD5)
aa7d91597a48d2cd69157663c291769e
Author(s)
Nikurashin, Maxim Anatolevich
Ferrari, Raffaele
Grisouard, Nicolas
Polzin, Kurt
Date Issued
November 2014
Journal
Journal of Physical Oceanography
Publisher
American Meteorological Society
Citation
Nikurashin, Maxim, Raffaele Ferrari, Nicolas Grisouard, and Kurt Polzin. “The Impact of Finite-Amplitude Bottom Topography on Internal Wave Generation in the Southern Ocean.” J. Phys. Oceanogr. 44, no. 11 (November 2014): 2938–2950. ©
2014 American Meteorological Society
Version
Final published version
Abstract
Direct observations in the Southern Ocean report enhanced internal wave activity and turbulence in a kilometer-thick layer above rough bottom topography collocated with the deep-reaching fronts of the Antarctic Circumpolar Current. Linear theory, corrected for finite-amplitude topography based on idealized, two-dimensional numerical simulations, has been recently used to estimate the global distribution of internal wave generation by oceanic currents and eddies. The global estimate shows that the topographic wave generation is a significant sink of energy for geostrophic flows and a source of energy for turbulent mixing in the deep ocean. However, comparison with recent observations from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean shows that the linear theory predictions and idealized two-dimensional simulations grossly overestimate the observed levels of turbulent energy dissipation. This study presents two- and three-dimensional, realistic topography simulations of internal lee-wave generation from a steady flow interacting with topography with parameters typical of Drake Passage. The results demonstrate that internal wave generation at three-dimensional, finite bottom topography is reduced compared to the two-dimensional case. The reduction is primarily associated with finite-amplitude bottom topography effects that suppress vertical motions and thus reduce the amplitude of the internal waves radiated from topography. The implication of these results for the global lee-wave generation is discussed.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1175/jpo-d-13-0201.1
