Python Ocean Model (pyOM)
Introduction
A numerical Ocean Circulation Model to configure and to integrate idealized numerical simulations with python (GUI) and a standard Fortran90 frontend.
In both cases, the dynamical core of the model is written in Fortran90.
Features
- Surface pressure or implicit linear free surface formulation
- Non-hydrostatic version
- 1D domain decomposition for parallel computation
Assumptions and Approximations
- Fully incompressible thermodynamics
- Boussinesq approximation
- ( Volume conservation and Buoyancy perturbations in gravity term)
- Cartesian and beta-plane approximation
Resources
Prerequisites and Installation
Prerequisites
1. Unix system
2. Fortran 90 compiler
3. Fortran and Python front ends NetCDF-library
Installation (only for students of UHH)
1. Login at the remote server thunder1
ssh thunder1
2. Once you logged in, make a new directory where the model code should be placed. Name the directory as dir (for instance)
3. Find home directory of u241155
finger u241155
and copy the following directory to your new directory to get src files for compiling
cp home/zmaw/u241155/pyOM_thunder <dir>
4. Now all model code and Fortran subroutines and Python methods for the model configuration can be found in <dir>
List of Directories in <dir>
* ./for_src: Fortran subroutines used by both Fortran and Python front end
* ./py_src: Python modules and extension modules
* ./py_config: Configuration examples of Python front end
* ./for_config: Configuration examples for Fortran front end
* ./doc: contains documentation
* ./bin: contains executable of Fortran front end after successful compilation
Model Configurations
Allocating the model variables
* set_parameter :sets all important fixed model parameter
In the model setup
* set_coriolis : sets the (vertical and horizontal) Coriolis parameter.
* initial_conditions :sets the initial conditions.
* topography : set the topography.
For each time step
* boundary_conditions : set the surface boundary conditions.
* restoring_zones : set the interior sources and sinks for density.
* momentum_restoring_zones : set the interior sources and sinks for momentum.
* tracer_sources : set interior sources and sinks for the passive tracer. Also sets the surface boundary conditions.
Sample Configurations
Kelvin-Helmholtz Instability
kelvin_helm1.py
Rayleigh–Bénard Convection
rayleigh.py
Eady's Baroclinic Instability
eady1.py / eady2.py
Eddy-driven zonal jets
jets1.py
Thermohaline Circulation
THC1.py
Southern Ocean Circulation
acc1.py
ENSO Response
enso1.py
Equatorial Waves
eq_waves1.py
Isopycnal Diffusion
isopyc_test1.py
An example of the python GUI for Eady's baroclinic instability case is shown below.
