New regional configuration setup: open boundaries

Configurations Regional
21

Yes, you are right, the ncdump is wrong ! It does not agree with what I wrote and with the code (fldread.F90):

     !!---------------------------------------------------------------------
     !!                    ***  ROUTINE fld_map_core  ***
     !!----------------------------------------------------------------------
      !
      ! structured BDY with rimwidth > 1                     : idim_read(2) == rimwidth /= 1
      ! structured BDY with rimwidth == 1 or unstructured BDY: idim_read(2) == 1
      !
      IF( idim_read(2) > 1 ) THEN    ! structured BDY with rimwidth > 1  
         DO jk = 1, idim_bdy(3)
            DO jb = 1, idim_bdy(1)
               im1 = kmap(jb) - 1
               jj = im1 / idim_read(1) + 1
               ji = MOD( im1, idim_read(1) ) + 1
               pdta_bdy(jb,1,jk) =  pdta_read(ji,jj,jk)
            END DO
         END DO
      ELSE
         ! ...
      ENDIF

Taking the same example, but presumably at the right place this time in the operational repository, here is what we get for the western boundary (along boundary dimension “Y” first):

netcdf NEATL36_obcdta_west_y2017m04d30 {
dimensions:
	Y = 1874 ;
	X = 30 ;
	Z = 50 ;
	T = UNLIMITED ; // (1 currently)
variables:
	int Y(Y) ;
		Y:standard_name = "projection_y_coordinate" ;
		Y:units = "1" ;
		Y:axis = "Y" ;
		Y:grid_point = "T" ;
	int X(X) ;
		X:standard_name = "projection_x_coordinate" ;
		X:units = "1" ;
		X:axis = "X" ;
		X:grid_point = "T" ;
	int Z(Z) ;
		Z:standard_name = "projection_z_coordinate" ;
		Z:units = "1" ;
		Z:axis = "Z" ;
		Z:grid_point = "T" ;
	int T(T) ;
		T:standard_name = "projection_t_coordinate" ;
		T:units = "1" ;
		T:axis = "T" ;
		T:grid_point = "T" ;
	float deptht(Z) ;
		deptht:units = "m" ;
		deptht:positive = "down" ;
		deptht:long_name = "Vertical T levels" ;
		deptht:standard_name = "depth" ;
		deptht:axis = "Z" ;
		deptht:associate = "Z" ;
		deptht:grid_point = "T" ;
		deptht:_FillValue = 0.f ;
	float time_counter(T) ;
		time_counter:calendar = "gregorian" ;
		time_counter:standard_name = "time" ;
		time_counter:long_name = "Time axis" ;
		time_counter:axis = "T" ;
		time_counter:units = "seconds since 2006-10-11 00:00:00" ;
		time_counter:time_origin = "2006-OCT-11 00:00:00" ;
		time_counter:associate = "T" ;
		time_counter:grid_point = "T" ;
		time_counter:_FillValue = 0.f ;
	double nav_lon(X, Y) ;
		nav_lon:_FillValue = 1.e+20 ;
		nav_lon:long_name = "Longitude_T" ;
		nav_lon:units = "degrees_east" ;
		nav_lon:associate = "Y X" ;
		nav_lon:grid_point = "T" ;
	double nav_lat(X, Y) ;
		nav_lat:_FillValue = 1.e+20 ;
		nav_lat:long_name = "Latitude_T" ;
		nav_lat:units = "degrees_north" ;
		nav_lat:associate = "Y X" ;
		nav_lat:grid_point = "T" ;
	float sossheig(T, X, Y) ;
		sossheig:units = "m" ;
		sossheig:add_offset = 0.f ;
		sossheig:scale_factor = 1.f ;
		sossheig:long_name = "Sea Surface Height" ;
		sossheig:short_name = "sossheig" ;
		sossheig:online_operation = "N/A" ;
		sossheig:interval_operation = 86400 ;
		sossheig:interval_write = 86400 ;
		sossheig:coordinates = "nav_lon nav_lat" ;
		sossheig:standard_name = "sea_surface_height" ;
		sossheig:associate = "T Y X" ;
		sossheig:grid_point = "T" ;
		sossheig:extrapolation = "dist_weight" ;
		sossheig:interpolation = "cubic" ;
		sossheig:src_file = "PSY4V3R1_1dAV_20170430_20170501_grid2D_R20170510.nc" ;
		sossheig:src_i_indices = 3207, 3218 ;
		sossheig:src_j_indices = 1820, 2446 ;
		sossheig:refinment_factor = 3, 3 ;
		sossheig:_FillValue = 0.f ;
	float vomecrty(T, Z, X, Y) ;
		vomecrty:units = "m s-1" ;
		vomecrty:add_offset = 0.f ;
		vomecrty:scale_factor = 1.f ;
		vomecrty:long_name = "Meridional velocity" ;
		vomecrty:standard_name = "sea_water_y_velocity" ;
		vomecrty:short_name = "vomecrty" ;
		vomecrty:online_operation = "N/A" ;
		vomecrty:interval_operation = 86400 ;
		vomecrty:interval_write = 86400 ;
		vomecrty:coordinates = "nav_lon nav_lat" ;
		vomecrty:associate = "T Z Y X" ;
		vomecrty:grid_point = "V" ;
		vomecrty:extrapolation = "dist_weight" ;
		vomecrty:interpolation = "cubic" ;
		vomecrty:src_file = "PSY4V3R1_1dAV_20170430_20170501_gridV_R20170510.nc" ;
		vomecrty:src_i_indices = 3207, 3218 ;
		vomecrty:src_j_indices = 1820, 2446 ;
		vomecrty:refinment_factor = 3, 3 ;
		vomecrty:_FillValue = 0.f ;
	float vozocrtx(T, Z, X, Y) ;
		vozocrtx:units = "m s-1" ;
		vozocrtx:add_offset = 0.f ;
		vozocrtx:scale_factor = 1.f ;
		vozocrtx:long_name = "Zonal velocity" ;
		vozocrtx:standard_name = "sea_water_x_velocity" ;
		vozocrtx:short_name = "vozocrtx" ;
		vozocrtx:online_operation = "N/A" ;
		vozocrtx:interval_operation = 86400 ;
		vozocrtx:interval_write = 86400 ;
		vozocrtx:coordinates = "nav_lon nav_lat" ;
		vozocrtx:associate = "T Z Y X" ;
		vozocrtx:grid_point = "U" ;
		vozocrtx:extrapolation = "dist_weight" ;
		vozocrtx:interpolation = "cubic" ;
		vozocrtx:src_file = "PSY4V3R1_1dAV_20170430_20170501_gridU_R20170510.nc" ;
		vozocrtx:src_i_indices = 3207, 3218 ;
		vozocrtx:src_j_indices = 1820, 2446 ;
		vozocrtx:refinment_factor = 3, 3 ;
		vozocrtx:_FillValue = 0.f ;
	float vosaline(T, Z, X, Y) ;
		vosaline:units = "PSU" ;
		vosaline:add_offset = 0.f ;
		vosaline:scale_factor = 1.f ;
		vosaline:long_name = "Salinity" ;
		vosaline:standard_name = "sea_water_salinity" ;
		vosaline:short_name = "vosaline" ;
		vosaline:online_operation = "N/A" ;
		vosaline:interval_operation = 86400 ;
		vosaline:interval_write = 86400 ;
		vosaline:coordinates = "nav_lon nav_lat" ;
		vosaline:associate = "T Z Y X" ;
		vosaline:grid_point = "T" ;
		vosaline:extrapolation = "dist_weight" ;
		vosaline:interpolation = "cubic" ;
		vosaline:src_file = "PSY4V3R1_1dAV_20170430_20170501_gridS_R20170510.nc" ;
		vosaline:src_i_indices = 3207, 3218 ;
		vosaline:src_j_indices = 1820, 2446 ;
		vosaline:refinment_factor = 3, 3 ;
		vosaline:_FillValue = 0.f ;
	float votemper(T, Z, X, Y) ;
		votemper:units = "degree_Celsius" ;
		votemper:add_offset = 0.f ;
		votemper:scale_factor = 1.f ;
		votemper:long_name = "Temperature" ;
		votemper:standard_name = "sea_water_potential_temperature" ;
		votemper:short_name = "votemper" ;
		votemper:online_operation = "N/A" ;
		votemper:interval_operation = 86400 ;
		votemper:interval_write = 86400 ;
		votemper:coordinates = "nav_lon nav_lat" ;
		votemper:associate = "T Z Y X" ;
		votemper:grid_point = "T" ;
		votemper:extrapolation = "dist_weight" ;
		votemper:interpolation = "cubic" ;
		votemper:src_file = "PSY4V3R1_1dAV_20170430_20170501_gridT_R20170510.nc" ;
		votemper:src_i_indices = 3207, 3218 ;
		votemper:src_j_indices = 1820, 2446 ;
		votemper:refinment_factor = 3, 3 ;
		votemper:_FillValue = 0.f ;

// global attributes:
		:Conventions = "CF-1.5" ;
		:Grid = "ARAKAWA-C" ;
		:periodicity = 0. ;
		:Created_by = "SIREN create_boundary" ;
		:Creation_date = "2017-05-08 10:46:22" ;
		:bdy_ind = 2. ;
		:bdy_width = 30. ;
		:bdy_deb = 2. ;
		:bdy_end = 1875. ;
}

and the eastern:

22

My first guess is “no”

23

Thank you Jérôme!
And sorry for bothering again [I just want to make sure I really apply the correct data-structure, to exclude this from the list of possible issues for some spurious signals I see evolving from the boundaries]:
From your new ncdumps I read cross boundary dimension (X) first: e.g. votemper(T, Z, X, Y)
This is what seems to work in my case as well.
I have to admit that it’s pretty hard for me to follow the definition of these fields through the code.

24

No problem Franziska. This is far from being clear…

I don’t get your point. These are East and West segments: 1st dimension of arrays (and in the definition of dimensions in the netcdf file, that’s important) is the along boundary direction, e.g. Y here (len=1874). X (len=30=max size of the relaxation zone) is the cross boundary direction. You may have been confused by the names “X”, “Y” but that doesn’t matter.

25

:thinking:
To my understanding and what I see from testing different options it’s not the order in which dimensions occur in the file but in which they occur in the variables.
Here are two of my boundary data sets:

southern (northern is similar although sorted in reverse order along geographical latitude)

netcdf boundary_fields_l120_south_10_grid_U_y2015 {
dimensions:
        depth = 120 ;
        time = UNLIMITED ; // (365 currently)
        y = 9 ;
        x = 917 ;
variables:
        float depth(depth) ;
                depth:_FillValue = NaNf ;
        int64 time(time) ;
                time:long_name = "Time (hours since 1950-01-01)" ;
                time:standard_name = "time" ;
                time:axis = "T" ;
                time:_ChunkSizes = 1 ;
                time:_CoordinateAxisType = "Time" ;
                time:units = "days since 2015-01-01 12:00:00" ;
                time:calendar = "proleptic_gregorian" ;
        double uo(time, depth, y, x) ;
                uo:_FillValue = -9999. ;
                uo:long_name = "Eastward velocity" ;
                uo:standard_name = "eastward_sea_water_velocity" ;
                uo:units = "m s-1" ;
                uo:unit_long = "Meters per second" ;
                uo:cell_methods = "area: mean" ;
                uo:_ChunkSizes = 1, 7, 341, 720 ;
        double x(x) ;
                x:_FillValue = NaN ;
        double y(y) ;
                y:_FillValue = NaN ;

and western

x always referring to “longitude”, y referring to “latitude”