CDO

Uwe,

I have uploaded a small size ocean temp. data "thetao_Omon_MIROC5_piControl_r1i1p1_255001-255002.lite.nc".
 I want to regrid this rotated polar grid data to regular 1x1 grid data using "CDO" command.

"CDO" remap command works for most CMIP5 ocean temp. data except for the Japanese model "MIROC5".

I can not generate the weights, see below.

Could you direct me how to regrid it to regular 1x1 horizontal grid?

Thanks,
    Tao

/Volumes/tzhang5/tzhang5/CMIP5/ocntmp> cdo genbil,r360x180
thetao_Omon_MIROC5_piControl_r1i1p1_255001-255002.lite.nc
thetao_Omon_MIROC5_bilwgt.nc
Warning (scanVarAttributes) : NetCDF: Variable not found - areacello

cdo genbil (Abort): Unsupported grid type: generic

First check your netCDF with the CDO operator sinfon, here is the result:

   File format: netCDF
    -1 : Institut Source   Name        Time Typ  Grid Size Num  Levels Num
     1 : unknown  unknown  depth       con  F32     57344   1       1   1
     2 : unknown  unknown  eta         var  F32     57344   1       1   1
     3 : unknown  unknown  sigma_bnds  con  F64         2   2       2   2
     4 : unknown  unknown  thetao      var  F32     57344   3       2   2
     5 : unknown  unknown  zlev_bnds   con  F64         2   2       2   2
   Horizontal grids :
     1 : lonlat       > size      : dim = 57344  nlon = 256  nlat = 224
                        rlon      : first = -0.703125  last = 357.890625  inc = 1.40625  degrees  circular
                        rlat      : first = -88.081279  last = 88.081279  degrees
                        available : xbounds ybounds
     2 : generic      > size      : dim = 2
     3 : curvilinear  > size      : dim = 57344  nx = 256  ny = 224
                        lon       : min = 0.0163634736  max = 359.994476  degrees_east  circular
                        lat       : min = -89.8470459  max = 89.8470459  degrees_north
                        available : xvals yvals xbounds ybounds
   Vertical grids :
     1 : surface                  : 0 
     2 : generic                  : 1.25 3.75 
                           bounds : 0-2.5 2.5-5 
   Time axis :  2 steps
     RefTime =  2000-01-01 00:00:00  Units = days  Calendar = 365DAYS  Bounds = true
  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss  YYYY-MM-DD hh:mm:ss
  2550-01-16 12:00:00  2550-02-15 00:00:00

CDO found 5 data variables on 3 different grid types. One of them is a generic grid (variables: sigma_bnds and zlev_bnds). generic means CDO does not find geographic coordinates for that grid. In this case you have to select only those variables you want to interpolate. Here is an example:

cdo remapbil,r360x180 -selname,thetao ifile ofile

If you want to use genbil you have to select the variables for every remap command:

cdo genbil,r360x180 -selname,thetao ifile weights
cdo remap,r360x180,weights -selname,thetao ifile ofile