[MITgcm-support] external forcing input interpolation

[Dimitris Menemenlis]

> 1- How is the interpolation in longitude done since there
>      is no specification of the longitude range of the model
>      grid in the "data" file (like there is in latitude by specifying
>     phiMin)?

for longitude there is thetamin, which defaults to 0 if not specified

> 1.5- If i am correct and by checking the code, field_lon_inc
>     and field_lat_inc can be negative, right?

I have never tried negative increments

> 2- I don't understand in the manual (page 299) and in the
>     global_with_exf exemple, the value for hflux_lat_inc=39*4.
> 
>    Shouldn't that be just: hflux_lat_inc=4    ?
> 
>    Or if not, shouldn't we have hflux_lon_inc=89*4   ?

hflux_lat_inc is a vector, which allows variable meridional spacing of input grid

hflux_lon_inc is a scalar, that is, it assumes homogeneous zonal spacing of 
input grid