CDO

Hello,

I am using climate projection data out of the Climex_project to calculate changes in regional precipitation extremes. In the data set description I cant find any information about the used coordinate system of the data. I just need the precipitation data out of a single grid sell. I used the lon lat coordinates of the center point of my watershed to extract the nearest gridcell (using: remapnn,lon=8.730004_lat=51.491288).

Applying the cdo griddes command gives me following information:

scanningMode = 64
gridtype = projection
gridsize = 78400
xsize = 280
ysize = 280
xname = rlon
xlongname = "longitude in rotated pole grid"
xunits = "degrees"
yname = rlat
ylongname = "latitude in rotated pole grid"
yunits = "degrees"
xfirst = -21.6649932861328
xinc = 0.11000000875056
yfirst = -16.7749977111816
yinc = 0.10999999507781
scanningMode = 64
grid_mapping = rotated_pole
grid_mapping_name = rotated_latitude_longitude
grid_north_pole_latitude = 39.25f
grid_north_pole_longitude = 198.f
north_pole_grid_longitude = 0.f

I don't understand weather I have to reproject my whole files first (in total 360 with 78000 gridpoints) before I can extract the required coordinates or if the rotated_pole is just important when I do use the rlon and rlat values. I already did cut the files and merged them together, right now I am just not 100% sure if I extracted the correct location and want to be sure before I continue with the statistical calculations.

Here the information printed out when using the cdo sinfo command:

File format : NetCDF4 classic zip
    -1 : Institut Source   T Steptype Levels Num    Points Num Dtype : Parameter ID
     1 : unknown  unknown  v instant       1   1     78400   1  F32z : -1
   Grid coordinates :
     1 : curvilinear              : points=78400 (280x280)
                              lon : -24.98154 to 37.91363 degrees_east
                              lat : 30.42796 to 64.665 degrees_north
                          mapping : rotated_latitude_longitude
                             rlon : -21.66499 to 9.025009 by 0.11 degrees
                             rlat : -16.775 to 13.915 by 0.11 degrees

Thank you in advance for your help! I just want to be sure that I don't find out that I did all my calculations for a wrong grid cell because I didn't reproject it.

Greetings:
Felix