Annotation of /MITgcm/verification/global_with_exf/README

heimbach@mit.edu 07-Nov-2002.
This verification experiment is almost identical to the
global_ocean.90x40x15 experiment, except that it uses
the exf (and cal) package instead of the 
external_fields_load routine.
To obtain identical results between the two experiments,
the following 2 modifications are necessary:
1. in external_fields_load.F:
   replace the line
      Imytm=int(myTime*rdt+0.5)
   by
      Imytm=int((myTime+1296000.)*rdt+0.5)
2. in exf_set_climsst.F:
   comment the 'quality' check, i.e. avoid the setting
   to freezing temperature if less than climtempfreeze.

================================

menemenlis@jpl.nasa.gov 05-Aug-2003

On-the-fly spatial interpolation has been added to pkg/exf.
It is enabled by defining CPP option USE_EXF_INTERPOLATION
in EXF_CPPOPTIONS.h or in ECCO_CPPOPTIONS.h
Both bi-linear and bi-cubic (#define BICUBIC) are supported.

This package is a placeholder until more general coupler
is made available by ESMF project.  It assumes that input
grid is Cartesian with arbitrary latitude increments in the
y-direction but with equidistant longitude increments in
the x-direction.  The input grid must encompass the complete
output grid in the y-direction (i.e., extrapolation is not
supported) and it is assumed that the grid is periodic in
the x-direction.

The verification/global_with_exf experiment has been modified
to use the USE_EXF_INTERPOLATION option, the input grids
being defined by variables *_lon0, *_lon_inc, *_lat0, *_lat_inc
*_nlon and *_nlat in input/dat.exf and input/data.exf_clim

   *_lon0, *_lat0    :: lon and lat of sw corner of global input grid
   *_lon_inc         :: scalar x-grid increment
   *_lat_inc         :: vector y-grid increments
   *_nlon and *_nlat :: input x-grid and y-grid size

In this particular example the input and output grids are
the same, so the results of the verification experiment remained
unchanged from before.
1	heimbach	1.2	heimbach@mit.edu 07-Nov-2002.
2			This verification experiment is almost identical to the
3			global_ocean.90x40x15 experiment, except that it uses
4			the exf (and cal) package instead of the
5			external_fields_load routine.
6			To obtain identical results between the two experiments,
7			the following 2 modifications are necessary:
8			1. in external_fields_load.F:
9			replace the line
10			Imytm=int(myTime*rdt+0.5)
11			by
12			Imytm=int((myTime+1296000.)*rdt+0.5)
13			2. in exf_set_climsst.F:
14			comment the 'quality' check, i.e. avoid the setting
15			to freezing temperature if less than climtempfreeze.
16	dimitri	1.3
17			================================
18
19			menemenlis@jpl.nasa.gov 05-Aug-2003
20
21			On-the-fly spatial interpolation has been added to pkg/exf.
22			It is enabled by defining CPP option USE_EXF_INTERPOLATION
23			in EXF_CPPOPTIONS.h or in ECCO_CPPOPTIONS.h
24			Both bi-linear and bi-cubic (#define BICUBIC) are supported.
25
26			This package is a placeholder until more general coupler
27			is made available by ESMF project. It assumes that input
28			grid is Cartesian with arbitrary latitude increments in the
29			y-direction but with equidistant longitude increments in
30			the x-direction. The input grid must encompass the complete
31			output grid in the y-direction (i.e., extrapolation is not
32			supported) and it is assumed that the grid is periodic in
33			the x-direction.
34
35			The verification/global_with_exf experiment has been modified
36			to use the USE_EXF_INTERPOLATION option, the input grids
37			being defined by variables _lon0, _lon_inc, _lat0, _lat_inc
38			_nlon and _nlat in input/dat.exf and input/data.exf_clim
39
40			_lon0, _lat0 :: lon and lat of sw corner of global input grid
41			*_lon_inc :: scalar x-grid increment
42			*_lat_inc :: vector y-grid increments
43			_nlon and _nlat :: input x-grid and y-grid size
44
45			In this particular example the input and output grids are
46			the same, so the results of the verification experiment remained
47			unchanged from before.