Sub-inertial modulation of nonlinear Kelvin waves in the coastal zone
Observational evidence is presented for interaction between nonlinear internal Kelvin waves at the ω<sub>t,i</sub> (where the ω<sub>t</sub> is the semidiurnal frequency and the ω<sub>i</sub> is the inertial frequency) and random oscil...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-06-01
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| Series: | Nonlinear Processes in Geophysics |
| Online Access: | http://www.nonlin-processes-geophys.net/20/357/2013/npg-20-357-2013.pdf |
| Summary: | Observational evidence is presented for interaction between nonlinear internal Kelvin waves at the ω<sub>t,i</sub> (where the ω<sub>t</sub> is the semidiurnal frequency and the ω<sub>i</sub> is the inertial frequency) and random oscillations of the background coastal current at the sub-inertial Ω frequency in the Japan/East Sea. Enhanced coastal currents at the sum ω<sub>+</sub> and difference ω-frequencies ω<sub>±</sub>=ω<sub>t,i</sub> ± Ω have properties of propagating Kelvin waves, which suggests permanent energy exchange from the sub-inertial band to the mesoscale ω<sub>±</sub> band. This interaction may be responsible for a greater-than-predicted intensification, steepening and breaking of boundary-trapped Kelvin waves. The problem of interaction between the nonlinear Kelvin wave at the frequency ω and the low-frequency narrowband noise with representative frequency Ω≪ω is investigated using the theory of nonlinear weak dispersion waves. |
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| ISSN: | 1023-5809 1607-7946 |