Numerical Simulations of the California Current: Filament Formation as Related to Baroclinic Instability.
Abstract
The California Current System, CCS, consists of four separate currents that are spatially and seasonally distributed of the west coast of the United States. They are: 1) the California Current, a southward flowing surface jet; 2) the California Undercurrent, a northward flowing sub-surface jet; 3) the Davidson Current, a poleward flowing surface jet north of Point Conception; and 4) the Southern California Countercurrent, a northward flowing surface current south of Point Conception in the California Bight. Offshore jets or filaments are a well observed phenomenon in the CCS. Their surface and subsurface structures as well as their spatial and temporal variability are well documented. The methods by which these filaments are formed is not as well understood as their structural form. The most common generation theories are: 1) variations in wind stress coupled with topographic irregularities, 2) dynamic instability, and 3) geostrophic turbulence. This thesis attempts to identify the factor(s) responsible for filament formation south of Cape Mendocino by numerically simulating the CCS using a two-layer, non-linear, primitive equation model. It is shown that baroclinic instability is the primary method by which filaments are formed in this region and that other factors such as barotropic instability, friction and nonlinearities can alter the characteristics of the fastest growing baroclinically unstable wave. Keywords: PE ocean model; Coastal jet flow; Topography; Eddies; Friction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1987
- Accession Number
- ADA187573
Entities
People
- David A. Olivier
Organizations
- Naval Postgraduate School