The ocean model we use is the Hamburg Ocean Primitive Equation (HOPE) model, version 2.4, produced by the Max Plank Institut for Meteorologie in Hamburg, Germany. As the name would suggest, it's a primitive equation model formulated on constant levels. The folks in Hamburg spent a lot of effort on getting the mixing parameterizations right for the tropical Pacific, and it really shows; I'm not aware of any other primitive equation ocean model that does as good a job reproducing what actually happened in the tropical Pacific when you force it with historically observed winds. Despite that, technology marches ever onwards, and we are always evaluating new models to see how well they do.
The model is formulated on an "E-grid", which is laid out in a diamond shape rather than a box. Because of this, it's somewhat problematical quoting the resolution of the model in a constant latitude/longitude framework. But ignoring that difficulty for the moment, it's fair to say that the resolution is approximately 1 degree in longitude by 0.5 degrees in latitude near the equator. Outside of the tropics, the latitudnal gridspacing slowly increases to about 1.5 degrees. This lets us keep good model resolution in the area of interest while still covering most of the Pacific ocean.
Last modified: 25 June 1997
Copyright © 2000 David W. Pierce. All rights reserved.