Barotropic to Baroclinic Energy Conversion across Topographically Rough Straits with Application to the Luzon Strait
Abstract
This is a joint University of North Carolina-University of California at San Diego (UNC-UCSD) project whose main goal is to assess the relative contribution of local dissipation versus far-field radiation of internal waves (IWs) generated by the barotropic tide flowing across topographically rough straits in the Western Pacific, with special emphasis on the Luzon Strait area. In this report, we focus on the UNC contribution. The specific objectives of the project are as follows: (1) quantify the conversion rate of Barotropic to Baroclinic energy over rough topography, (2) quantify the amount of IW energy dissipated locally vs. the amount radiated into the far field, (3) examine the physical processes leading to dissipation on a small scale, and (4) understand the formation of nonlinear internal waves (NLIWs) emerging from the Luzon Strait. The objective is to use a combination of large-scale and intermediate-scale numerical models (GCM), small-scale turbulence models (LES), and theoretical models to explore the multi-scale process that begins when the large-scale barotropic tide injects energy into the baroclinic field. On the theoretical side, we have derived a model for the transient generated by IW interacting with topography which predicts how much shear can raise above mid-ocean values during the interaction with topography. We have acquired a Digital Elevation Model of the Luzon Strait area. With the aid of climatological data (GFDL), we have calculated maps showing how much the Richardson number can be elevated above the value observed without boundary interaction. Following a discussion at the last meeting in Honolulu, we also have run a simulation of linear mode-1 IWs approaching at different angles to test the hypothesis that NLIWs are generated by the confluence of linear IWs approaching from different directions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2009
- Accession Number
- ADA526909
Entities
People
- Alberto Scotti
- S. Mitran
Organizations
- University of North Carolina at Chapel Hill