[ncl-talk] question to the NCL latlon_to_SCRIP function

[chenhuansheng at mail.iap.ac.cn]

Dear all,

I used the latlon_to_SCRIP function to generate  lat-lon grid file with SCRIP format which will then be used as input files of the ESMF application "ESMF_RegridWeightGen".
When I applied latlon_to_SCRIP to 1x1, 0.5x0.5 and 0.25x0.25 grids, the output results were right. However, when I applied latlon_to_SCRIP to 0.1x0.1 grids, the output results 
are wrong. Do the latlon_to_SCRIP function support to generate a 0.1x0.1 grid file? Can you help me to solve this problem? 
Thank you very much.

The code used  to generate the 0.25x0.25 grids are as follows:
_______________
Opt                = True
Opt at LLCorner       = (/ -89.875d, -179.875d/)
Opt at URCorner       = (/  89.875d,  179.875d/)
Opt at ForceOverwrite = True
Opt at PrintTimings   = True
latlon_to_SCRIP(srcGridName,"0.25x0.25",Opt)
delete(Opt)
________________

The header of the output netcdf file is as follows: 
________________
dimensions:
        grid_size = 1036800 ;
        grid_corners = 4 ;
        grid_rank = 2 ;
variables:
        int grid_dims(grid_rank) ;
        double grid_center_lat(grid_size) ;
                grid_center_lat:units = "degrees" ;
        double grid_center_lon(grid_size) ;
                grid_center_lon:units = "degrees" ;
        int grid_imask(grid_size) ;
                grid_imask:units = "unitless" ;
        double grid_corner_lat(grid_size, grid_corners) ;
                grid_corner_lat:units = "degrees" ;
        double grid_corner_lon(grid_size, grid_corners) ;
                grid_corner_lon:units = "degrees" ;

// global attributes:
                :date_created = "Thu Oct 15 19:49:54 CST 2015" ;
                :Createdby = "ESMF_regridding.ncl" ;
                :Conventions = "SCRIP" ;
                :title = "0.25x0.25 grid" ;
data:

grid_dims = 1440, 720 ;
________________


The code used  to generate the 0.1x0.1 grids are as follows:
_______________
Opt                = True
Opt at LLCorner       = (/ -89.95d, -179.95d/)
Opt at URCorner       = (/  89.95d,  179.95d/)
Opt at ForceOverwrite = True
Opt at PrintTimings   = True
latlon_to_SCRIP(srcGridName,"0.1x0.1",Opt)
delete(Opt)
________________

The header of the output netcdf file is as follows: 
_____________
dimensions:
        grid_size = 6474601 ;
        grid_corners = 4 ;
        grid_rank = 2 ;
variables:
        int grid_dims(grid_rank) ;
        double grid_center_lat(grid_size) ;
                grid_center_lat:units = "degrees" ;
        double grid_center_lon(grid_size) ;
                grid_center_lon:units = "degrees" ;
        int grid_imask(grid_size) ;
                grid_imask:units = "unitless" ;
        double grid_corner_lat(grid_size, grid_corners) ;
                grid_corner_lat:units = "degrees" ;
        double grid_corner_lon(grid_size, grid_corners) ;
                grid_corner_lon:units = "degrees" ;

// global attributes:
                :date_created = "Thu Oct 15 20:27:42 CST 2015" ;
                :Createdby = "ESMF_regridding.ncl" ;
                :Conventions = "SCRIP" ;
                :title = "0.1deg grid" ;
data:

grid_dims = 3599, 1799 ;
_____________
Why the grid_dims are 3599x1799?  I think it should be 3600x1800.


Yours Sincerely,
Huansheng Chen




陈焕盛（LAPC/IAP）
大气边界层物理和大气化学国家重点实验室
中国科学院大气物理研究所
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