projection_query
Replies (8)
RE: projection_query - Added by Karin Meier-Fleischer over 5 years ago
Hi Kunak,
I think, this script haven't had run ever. I wouldn't recommend to mix NCL and CDO in that way.
First, you have to add the coordinates attribute to your variables
ncatted -O -a coordinates,Deep_Blue_Aerosol_Optical_Depth_550_Land_mod04,c,c,"longitude latitude" \
-a coordinates,Aerosol_Cloud_Fraction_Land_mod04,c,c,"longitude latitude" \
all.nc all_coordinates.ncThen you can compute the weights
cdo genbil,r180x90 all_coordinates.nc weights.nc
Do the remapping
cdo remap,r180x90,weights.nc all_coordinates.nc out_kunal.nc
Create the plot of first timestep for e.g. Deep_Blue_Aerosol_Optical_Depth_550_Land_mod04
cdo grfill,device="png" -seltimestep,1 -selname,Deep_Blue_Aerosol_Optical_Depth_550_Land_mod04 out_kunal.nc plot_out_kunal
-Karin
RE: projection_query - Added by Karin Meier-Fleischer over 5 years ago
Yupp, the latitude and longitude coordinate variables are time depending. The time dependency must be
deleted which means you have to create one file per time step and delete the time dimension in
latitude and longitude. In my opinion CDO can't do that, so there comes NCL back into the game to
do that.
Here is a short Korn Shell script which generates the NCL script to read the data all_coordinates.nc
which we have created earlier, select the time step, delete the time in latitude and longitude and
calls CDO to do the remapping (and some plots, too ;). You can do the remapping in NCL without
CDO's, too, but we're here in the CDO forum, so let's do it this way.
myscript.ksh
#!/bin/ksh
cat << EOF > script.ncl
f = addfile("all_coordinates.nc","r")
time = f->time
ntime = dimsizes(f->time)
lat = f->latitude
lon = f->longitude
do t=0,ntime-1
system("rm -rf out_all_coordinates_delete_time_in_lonlat"+t+".nc")
outf := addfile("out_all_coordinates_delete_time_in_lonlat"+t+".nc","c")
outf->latitude = lat(t,:,:)
outf->longitude = lon(t,:,:)
outf->Deep_Blue_Aerosol_Optical_Depth_550_Land_mod04 = f->Deep_Blue_Aerosol_Optical_Depth_550_Land_mod04(t:t,:,:)
outf->Aerosol_Cloud_Fraction_Land_mod04 = f->Aerosol_Cloud_Fraction_Land_mod04(t:t,:,:)
delete(outf)
system("cdo -O genbil,r180x90 out_all_coordinates_delete_time_in_lonlat"+t+".nc weights_"+t+".nc")
system("cdo -O remap,r180x90,weights_"+t+".nc out_all_coordinates_delete_time_in_lonlat"+t+".nc out_kunal_"+t+".nc")
system("cdo grfill,device="+str_get_dq()+"png"+str_get_dq()+",min=0,max=1.0,interval=0.05,lon_min=60,lon_max=100,lat_min=10,lat_max=40 -selname,Aerosol_Cloud_Fraction_Land_mod04 out_kunal_"+t+".nc plot_kunal_all_coord_"+t)
end do
EOF
ncl script.ncl
exit
Run the script
ksh myscript.ksh
The plots are
Time step 1:
Time step 2:
Time step 3:
Time step 4:
Time step 5:
-Karin