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====== Reformatting files to AeroCom/HTAP standards ======

**Note: these commands cover the elder phase 3 naming scheme, but should nevertheless still usefull**

The AeroCom standard is described in the section "submitting to the AeroCom database".\\
https://wiki.met.no/aerocom/data_submission

Below simple nco commands are listed which can be of help to reformat.

A public set of format correction tools is under development and can be accessed here:\\
https://github.com/metno/aerocom-data-correction-tools

===== How to remind me of nco commands =====
Just type the command without arguments on a command line

===== How to rename variables =====
	 ncrename -v oldvar,newvar in.nc

===== How to add an attribute =====
	 ncatted -a experiment,newvar,a,c,"BASE" in.nc

===== Split files per variable  =====
	 cdo splitname in.nc


===== rename dimension =====
	 ncrename -O -d LATITUDE,y       temp.nc       

===== sums =====
	 ncap2 -O -s "LOAD_BCPOM[time,x,y]=LOAD_BC+LOAD_POM" ${file} ${file} 

===== compute vertical integrals =====
	 rm dummy.nc
	 ncwa -O -v AERH2O3D_AER   -a z -y ttl     ${file} dummy.nc  
	 ncrename -O -v AERH2O3D_AER,AERH2O_AER       dummy.nc 
	 ncks -F -A -v AERH2O_AER dummy.nc ${file} 

===== add variable to file =====
	 ncks -F -A -v AIRE temp.nc ${file}

===== make the time dimension unlimited =====
	 ncecat -O $file $file
	 ncpdq -O -a time,record $file $file
	 ncwa -O -a record $file $file
	 ncpdq -O -a time,y,x $file $file

===== turn z =====
	 ncpdq -O -a -z $file $file

===== create yearly mean file =====
from 12 months in one file
	 orgfile=MM_${model}.an${an}.mALLYEAR_an.nc 
	 ncwa -F -O -a time ${file} ${orgfile}

===== calculate yearly average =====
 fom 12 files each containing 1 month
	 ncra -F -O  modis_2000??.nc ${yearfile}

===== create record dimension =====
	 ncecat -O $file $file 

===== delete useless record dimension =====
	 ncwa -O -a record $file $file 

===== turn lat to have right order =====
 with interpolated files 
	 ncpdq -O -a "-y" $file $file 

===== Shift left and right hemispheres =====
	 file1=aire_1.nc
	 ncks -h -F -O -d x,1,180 $file $file1
	 file2=aire_2.nc
	 ncks -h -F -O -d x,181,360 $file $file2
	 ncap -O -s "x[x]=x-360" $file2 $file2

	 ncrcat -O $file2 $file1 $file
	\rm  $file1 $file2


===== Similar reorder of longitude =====
	ncecat -O $file $file 
	ncpdq -O -a x,record $file $file 
	ncwa -O -a record $file $file 

	file1=DD_${model}.an${AN}.mALLYEAR_1.nc
	ncks -F -O -d x,1,180 $file $file1

	file2=DD_${model}.an${AN}.mALLYEAR_2.nc
	ncks -F -O -d x,181,360 $file $file2
	ncap -O -s "x[x]=x-360" $file2 $file2
	
	ncrcat -O $file2 $file1 $file
	\rm  $file1 $file2	

	ncpdq -O -a time,y,x $file $file 

===== missing values ===== 
	ncatted -O -a missing_value,$var,o,f,0 ${file} 
	ncatted -O -a missing_value,$var,o,f,-9999 ${file} 

actually better use attribute _FillValue (see http://nco.sourceforge.net)


===== compute monthly mean files =====

    for IMTH in ${MTH[*]} ; do 
	file=DD_${model}.an${AN}.m${IMTH}.nc
	filemean=DD_${model}.an${AN}.m${IMTH}_m.nc 
	ncra -F -O  ${file} ${filemean}
    done


===== delete attributes =====
    ncatted -O -a ,,d,, interdummy.nc
    ncatted -h -a ,global,d,, interdummy.nc
    ncatted -h -a missing_value,,d,, interdummy.nc