ru/rv restart file coordinates incorrect

[jcwarner]

For a perfect restart, the variables ru and rv are written to the restart file. There is a discrepancy between the dimensions and coordinates attribute. For example :

 double rv(ocean_time, two, s_w, eta_v, xi_v) ;
                rv:long_name = "RHS of total v-momentum" ;
                rv:units = "meter4 second-2" ;
                rv:time = "ocean_time" ;
                rv:coordinates = "lon_v lat_v s_rho ocean_time" ;
                rv:field = "rv, scalar, series" ;
                rv:_FillValue = 1.e+37 ;

The dimension is s_w, but the coordinates attribute is s_rho. This gives a small error when viewing in ncview. '

[arango]

Yes, indeed. This is a tricky one. The right-hand-side terms (ru, rv) for the 3D momentum equations are defined a vertical RHO-points. However, a k=0 index is added for the 2D/3D coupling in step2d. This k=0 index contains the vertically integrated forcing term. This term is needed in perfect restart. The solution here is to set the coordinates attribute to:

                ru:coordinates = "lon_u lat_u s_w ocean_time" ;
                rv:coordinates = "lon_v lat_v s_w ocean_time" ;

This is achieved in def_rst.F by passing -u3dvar and -v3dvar variables (Aval(5)) to routine def_var.