1. Ocean Models By
Tom Snyder

2. Outline Beginning Ripples Modeling the Motion in the Ocean
A Sea of Math
The Next Wave

3. Ocean Models are difficult to portray
What are Ocean Models
A representation of information about Oceans
Ocean Models are difficult to portray
Eddies, multi-layered, interference, lots of information,
constant change
So why do Ocean Modeling
Large effect on Earth’s weather / climate.
Ship routing, long range forecasting
How is this related to Computational Science

4. Types of models
Free Surface Models
Rigid Lid Models
Z-level Models

5. Free Surface and Rigid Lid Models
Real oceans have deformities due to temperature, wind, tidal force, etc.
To include these deforming wind driven waves impairs the ability to do more accurate long term forecasting
Rigid Lid models put a Tupperware™ lid over the ocean.
Free Surface Models
Deals with the top “layer” of the ocean and all the deformities
Useful for short term studies

6. Z Level models
Any model that separates the ocean into distinct layers

7. Reduced Gravity Models
Looks at a layer or layers of the ocean that has a specific depth and ignores all motion below that.
Interesting fact about these models is that the deviations of the interface between the two layers are multiples of the free surface elevation, by a factor which is proportional to the ratio p/∆p
Z-level model

8. Mixed Layer Models Modeling of the top turbulent levels of the ocean.
Separates into distinct layers of reasonably similar salinity and temperature.
Must cope with the turbulence of the upper ocean.

9. Sigma-Coordinate Model
Another way of looking at Z level models
Better because it handles shallow areas better
Worse because it has a harder time managing the “steep” areas
calculation of the pressure gradient terms in the momentum equations

10. More math that you can shake a stick at
Each model has it’s own set of equations that represent differences in the ocean and handles certain situation in their own way
All must handle mass transports, grid spacing, time dependency
Differences in “steep” area between Z level models and Sigma Coordinate model
There are a set of equation that are more universal.
Friction (between various things), turbulence due to bottom topology
Plus a set of equations that deal with problems for certain models
Free surface elevation, Wind stress, Bottom stress

11. Computational Problems due to these inconsistencies
Change verses time/depth
Eddy solutions
Resolution verses Runtime Complexity

12. News about current models
The progression of technology and algorithms has a direct impact on the resolution that can be achieved.
New models are developed all the time for specific situations

13. Exercises Go to Goolge.com
Search for “Ocean Models” to learn more about different types of Models
Talks about high resolution and it’s importance for Ocean Models
Optimum Thermal Interpolation System (OTIS)