Ocean Science
Ocean Science
OS
Articles | Volume 11, issue 3
Articles | Volume 11, issue 3
https://doi.org/10.5194/os-11-439-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/os-11-439-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 11, issue 3
Research article
 | 
08 Jun 2015
Research article |  | 08 Jun 2015

Water level oscillations in Monterey Bay and Harbor

J. Park, W. V. Sweet, and R. Heitsenrether

Abstract. Seiches are normal modes of water bodies responding to geophysical forcings with potential to significantly impact ecology and maritime operations. Analysis of high-frequency (1 Hz) water level data in Monterey, California, identifies harbor modes between 10 and 120 s that are attributed to specific geographic features. It is found that modal amplitude modulation arises from cross-modal interaction and that offshore wave energy is a primary driver of these modes. Synchronous coupling between modes is observed to significantly impact dynamic water levels. At lower frequencies with periods between 15 and 60 min, modes are independent of offshore wave energy, yet are continuously present. This is unexpected since seiches normally dissipate after cessation of the driving force, indicating an unknown forcing. Spectral and kinematic estimates of these low-frequency oscillations support the idea that a persistent anticyclonic mesoscale gyre adjacent to the bay is a potential mode driver, while discounting other sources.

How to cite. Park, J., Sweet, W. V., and Heitsenrether, R.: Water level oscillations in Monterey Bay and Harbor, Ocean Sci., 11, 439–453, https://doi.org/10.5194/os-11-439-2015, 2015.
Received: 13 Oct 2014 – Discussion started: 20 Nov 2014 – Revised: 02 May 2015 – Accepted: 12 May 2015 – Published: 08 Jun 2015
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Short summary
Seiches in coastal bays can produce significant water level oscillations that impact maritime operations and introduce ecological stress. Monterey Bay, California, is found to have wave-driven short-period oscillations that can reinforce themselves, resulting in water level amplification. At longer periods the oscillations are not wave-driven and several potential forcing mechanisms are examined. A gyre offshore the bay is suggested as the driver, while other potential drivers are discounted.
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