Up to Transformations and interpolations
Hi, I am working on the coupled model CHIMERE-WRF. The source and the target grids are the same. I would like to create the remapping file rmp_src_to_dst_interpolation.nc without doing any interpolation. I created this file using the BILINEAR interpolation of SCRIPR but I have an error in the dimension of the CHIMERE grid in the remapping file (3713 values instead of 30720 which is the global size of the grid). Do you have any explanation ? Below is the namcouple I use to create the file rmp_src_to_dst_interpolation.nc : SENDCHO3 RECVCHO3 1 3600 1 FCHO3.nc EXPOUT 30720 1 30720 1 chim twrf R 0 R 0 SCRIPR BILINEAR LR SCALAR LATLON 1 Thanks, Best regards, Adrien
Hello Adrien,
You will find below a small fortran program (and an example of how to compile it) that creates a weight file for "identical" interpolation. You must use this weight file with the "MAPPING" namcouple option, instead of SCRIPR.
Best regards, Eric
--------------------------------------------PROGRAM make_oasis_weights
use netcdf
character(len=300) :: c_argument
integer*4 :: nb_grid_point, i
integer*4 :: dimids(4), il_file_id, il_var_id(5)
integer*4,allocatable,dimension(:) :: tmp
real(8),allocatable,dimension(:,:) :: tmp2
call getarg( 1, c_argument )
read(c_argument,'(i9)') nb_grid_point
status = nf90_create("oasis_weight.nc", NF90_CLOBBER, il_file_id)
status = nf90_def_dim(il_file_id, "num_wgts", 1, dimids(1))
status = nf90_def_dim(il_file_id, "num_links", nb_grid_point, dimids(2))
status = nf90_def_dim(il_file_id, "dst_grid_size", nb_grid_point, dimids(3))
status = nf90_def_dim(il_file_id, "src_grid_size", nb_grid_point, dimids(4))
status = nf90_def_var(il_file_id, "src_address", NF90_INT, dimids(2), il_var_id(1))
status = nf90_def_var(il_file_id, "dst_address", NF90_INT, dimids(2), il_var_id(2))
status = nf90_def_var(il_file_id, "remap_matrix", NF90_DOUBLE, dimids(1:2), il_var_id(3))
status = nf90_def_var(il_file_id, "dst_grid_area", NF90_DOUBLE, dimids(3), il_var_id(4))
status = nf90_def_var(il_file_id, "src_grid_area", NF90_DOUBLE, dimids(4), il_var_id(5))
status = nf90_enddef(il_file_id)
ALLOCATE (tmp(nb_grid_point))
ALLOCATE (tmp2(1,nb_grid_point))
DO i = 1, nb_grid_point
tmp(i) = i
ENDDO
tmp2 = 1.
status = nf90_put_var(il_file_id, il_var_id(1), tmp)
status = nf90_put_var(il_file_id, il_var_id(2), tmp)
status = nf90_put_var(il_file_id, il_var_id(3), tmp2)
status = nf90_put_var(il_file_id, il_var_id(4), RESHAPE ( tmp2, (/ nb_grid_point /) ) )
status = nf90_put_var(il_file_id, il_var_id(5), RESHAPE ( tmp2, (/ nb_grid_point /) ) )
status = nf90_close(il_file_id)
END PROGRAM make_oasis_weights
mpiifort make_oasis_weight.f90 -o make_oasis_weight.exe -O2 -xAVX -I/opt/softs/libraries/ICC13.1.4.183/netcdf-4.3.0/include -L/opt/softs/libraries/ICC13.1.4.183/netcdf-4.3.0/lib -lnetcdf -lnetcdff
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Dear Adrien, When two grids are identical with the same name there is no need to calculate any remapping file. By the way, if you want to create a remapping file between two identical grids, you could also use the DISTWGT remapping with one neighbour (see the User Guide https://oasis.cerfacs.fr/wp-content/uploads/sites/114/2021/02/GLOBC-Valcke_TR_OASIS3-MCT_2.0_2013.pdf, section 4.3). Best regards, Laure