Document Type
Article
Publication Date
9-1-2015
Department
Marine Science
School
Ocean Science and Engineering
Abstract
A global high-resolution ocean circulation model forced by atmospheric fields and the M2 tidal constituent is used to explore plausible scenarios for the damping of low-mode internal tides. The plausibility of different damping scenarios is tested by comparing the modeled barotropic tides with TPXO8, a highly accurate satellite-altimetry-constrained tide model, and by comparing the modeled coherent baroclinic tide amplitudes against along-track altimetry. Five scenarios are tested: (1) a topographic internal wave drag, argued here to represent the breaking of unresolved high vertical modes, applied to the bottom flow (default configuration), (2) a wave drag applied to the barotropic flow, (3) absence of wave drag, (4) a substantial increase in quadratic bottom friction along the continental shelves (with wave drag turned off), and (5) application of wave drag to the barotropic flow at the same time that quadratic bottom friction is substantially increased along the shelves. Of the scenarios tested here, the default configuration (1) yields the most accurate tides. In all other scenarios (2–5), the lack of damping on open ocean baroclinic motions yields baroclinic tides that are too energetic and travel too far from their sources, despite the presence of a vigorous mesoscale eddy field which can scatter and decohere internal tides in the model. The barotropic tides are also less accurate in the absence of an open ocean damping on barotropic motions, that is, in scenarios (3) and (4). The results presented here suggest that low-mode internal tides experience substantial damping in the open ocean.
Publication Title
Journal of Geophysical Research: Oceans
Volume
120
Issue
9
First Page
6057
Last Page
6071
Recommended Citation
Ansong, J.,
Arbic, B.,
Buijsman, M.,
Richman, J.,
Shriver, J.,
Wallcraft, A.
(2015). Indirect Evidence For Substantial Damping of Low-Mode Internal Tides In the Open Ocean. Journal of Geophysical Research: Oceans, 120(9), 6057-6071.
Available at: https://aquila.usm.edu/fac_pubs/18542
Comments
Ansong, 2015, "Indirect evidence for substantial damping of low‐mode internal tides in the open ocean", Journal of Geophysical Research: Oceans, 120, Citation number, 10.1002/2015jc010998. To view the published open abstract, go to https://doi.org/10.1002/2015jc010998.