At present, the only dynamical model included with the Harvard Ocean Prediction System is a Primitive Equation (PE) model.

The primitive equations are a simplification of the Navier-Stokes equations of fluid motion in a rotating coordinate system. The simplifying assumptions are:

Hydrostatic Approximation

The hydrostatic approximation neglects all vertical acceleration terms in the vertical momentum equation, except for gravity. This is a "thin fluid" approximation. It is valid when the horizontal length scales of the motion are much larger than the vertical length scales.

Boussinesq Approximation

The Boussinesq approximation replaces the density with its mean value everywhere except for the buoyancy term.

PE

The HOPS PE model is built on the Geophysical Fluid Dynamics Laboratory primitive equation model. Over the years, the HOPS group has added the following functionality to the original GFDL model:

• Terrain following coordinates
• Data Assimilation (via Optimal Interpolation)
• Surface Forcing
• Attached Biological Models
• Nested Sub-Domains
• Data Extraction (Lagrangian drifters, simulated sampling)
• Parameterization of tidal effects under the rigid-lid assumption

Dynamical Models

(pub/HOPS)

Directory	Files	Date (MM/DD/YYYY)	Size Compressed (bytes)	Size Uncompressed (bytes)
PE/	Readme.pe	08/21/2001		93221
	pe_9.6.tar.Z	08/21/2001	676568	2634240
	Ex_pe_9.6.tar.gz	08/21/2001	66336311	105523712