Large-Eddy Simulations of Mixing due to Solitary Waves, with Application to the CMO Experiment
Abstract
My long-term goal is to develop a facility for the efficient numerical modeling of waves and turbulence in the coastal oceans. The ultimate result will be improved methods for the parameterization of small-scale, coastal mixing processes (particularly sediment resuspension) in mesoscale models. During the Coastal Mixing and Optics (CMO) experiment, intensive measurements of internal waves and mixing events were obtained at a location on the continental shelf south of Martha's Vineyard. Intense mixing was observed, due both to the effects of local surface forcing and to the effects of remotely-generated nonlinear internal waves. The passage of Hurricane Edouard in September of 1996 caused dramatic changes in the vertical structure of the water column. Not only did the hurricane mix the ocean directly, it changed the nature of ongoing mixing processes that depend on background stratification, such as tide-generated solitons. Figure 1a shows a nonlinear wave of depression, observed before the passage of Hurricane Edouard, when stable stratification was confined to the upper 25m. After the hurricane passed (figure 1b), the near-surface zone was well mixed, and stratification was confined near the bottom. In that instance, waves of elevation were observed. Similar waves have been observed on the California shelf by Bogucki & Garrett (1997) and found to be very effective at mixing and sediment resuspension. As a result, it is likely that the change in mixing physics brought on by the hurricane persisted long after the event itself had passed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1998
- Accession Number
- ADA542110
Entities
People
- William D. Smyth
Organizations
- Oregon State University