QG-C

1.5-layer QG model.

This is a re-write of the Fortran code downloaded from
http://www.seas.harvard.edu/climate/eli/Downloads/QG200205011455.tar.gz.
The original Fortran code with some modifications was used in enkf-matlab
package and as a part of enkf-matlab in the following paper:

Sakov, P., Oke, P.R., 2008. A deterministic formulation of the ensemble Kalman
filter: an alternative to ensemble square root filters. Tellus 60A, 361-371.
https://doi.org/10.1111/j.1600-0870.2007.00299.x

Apart from being ported to C (except helmholtz.f90), this code adds a number of
convenience features and corrects inconsistencies in handling the geometry. 

EQUATION

The governing equation is presented in qg.pdf.

RUNNING

To run the model with default parameters, enter:

> ./qg -

To change parameters, run it as

> ./qg <parameter file>

The parameter file description is given by

> ./qg --describe-prm

Note: the default settings have negative harmonic friction, which is not quite
physical. For a more conventional variant you may try setting RKB = 0; RKH = 0.

COMPILING

Dependencies: NetCDF

The code has been developed under GNU/Linux platform. The Makefile assumes
availability of gcc and gfortran. It should be straightforward to compile this
code elsewhere.

To compile run:

> make