forcing-perturbation/prep_nem_forcings/eraint/orca1/wndpert.sh

#/bin/ksh
set -evx
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# This script computes daily perturbation from any NEMO forcing variable 
# ('u10', 'v10', 't2', 'q2', 'qsw', 'qlw', 'snow', 'precip') by picking up
# randomly monthly differences between ERAinterim and DFS4.3 forcing fields
# and interpolating these to a daily frequency (see more details in Guemas
# et al, 2014, Climate Dynamics)
#
# This script chases a fly with a flame thrower because it has been written
# while testing many different options. It works but it should be better 
# rewritten. 
# 
# History : Virginie Guemas - Initial version                         - 2012 
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
#                                Arguments
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lstvars=( 'u10' 'v10' )
             # Variables for which to compute and pick up random perturbations
lstmbs=( 1 2 3 4 )
             # List of members for which to build pertubation files
dfs2era='T'  # Interpolation from DFS4 to ERA (T) or from ERA to DFS (F) 
             # to build differences and perturbations
patherain='/cfu/scratch/vguemas/ERAint/' 
             # Path were to find the ERAinterim forcing files
pathdfsin='/cfu/scratch/vguemas/dfs4.3/'
             # Path were to find the DFS4.3 forcing files 
year0=1979   # Initial year of the reference period to compute perturbations
yearf=2006   # Last year of the reference period to compute perturbations
year1=2012   # First year for which to pick and build a pertubation file
year2=2014   # Last year for which  to pick and build a perturbation file
nstep=1460   # Number of time steps for a non-leap year : 1460 or 365
raw='F'      # Compute the timestep differences between raw ERA and DFS fields
             # If the script has already run once and the differences have
             # been stored, this option can be set to F for the step of picking
             # up random perturbations.
ano='F'      # Compute anomalies relative to a monthly-smoothed daily climatology
             # and the timestep differences between anomalies of ERA and DFS fields
             # raw=T needs to have run before. If the script has already run once and 
             # the timesteps differences have been stored, this option can be set to F. 
reorg='F'    # Reorganize the differences timestep per timestep all the years together
             # rather than year per year with all the timesteps. Works on anomalies
             # if wih is set to 'ano_' and raw differences if wih is set to '_'
             # Once the computation of differences and their reorganization has been 
             # performed once (raw=T, ano=T, reorg=T), the results are stored in directories
             # named according to the options set and raw, ano and reorg can be set
             # to F for the picking up.
wih='ano_'   # Which types needs to be picked for the perturbations
monmean='T'  # Compute monthly mean differences and pickup perturbations from monthly mean
             # differences rather than timestep differences 
pickup1='T'  # Pickup random perturbations for each member, variable, year, either
             # one per timestep or one per month
pickup2='F'  # Pickup 2 random perturbations and average them for each member, variable,
             # year, each timestep 
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

if [[ $dfs2era == T ]] ; then
  dif='eraint-dfs4.3'
  dir0='era-dfs'
else
  dif='dfs4.3-eraint'
  dir0='dfs-era'
fi

for var in ${lstvars[@]} ; do
  if [[ $raw == T ]] ; then
    for ((year=$year0;year<=$yearf;year++)) ; do
      cp ${patherain}/${var}_eraint_${year}.nc ${var}_eraint_${year}.nc
      ncpdq -O -U ${var}_eraint_${year}.nc ${var}_eraint_${year}.nc
      if [[ $nstep == 1460 ]] ; then
        case $year in
          1980|1984|1988|1992|1996|2000|2004|2008|2012|2016) 
          ncks -O -d time,0,232 ${var}_eraint_${year}.nc ${var}_eraint_${year}_1.nc
          ncks -O -d time,237, ${var}_eraint_${year}.nc ${var}_eraint_${year}_2.nc
          ncrcat -O ${var}_eraint_${year}_1.nc ${var}_eraint_${year}_2.nc ${var}_eraint_${year}.nc
          rm -f ${var}_eraint_${year}_1.nc ${var}_eraint_${year}_2.nc      
          ;;
        esac
      fi
      if [[ $nstep == 365 ]] ; then
        case $year in
          1980|1984|1988|1992|1996|2000|2004|2008|2012|2016)
          ncks -O -d time,0,58 ${var}_eraint_${year}.nc ${var}_eraint_${year}_1.nc
          ncks -O -d time,60, ${var}_eraint_${year}.nc ${var}_eraint_${year}_2.nc
          ncrcat -O ${var}_eraint_${year}_1.nc ${var}_eraint_${year}_2.nc ${var}_eraint_${year}.nc
          rm -f ${var}_eraint_${year}_1.nc ${var}_eraint_${year}_2.nc
          ;;
        esac
      fi 
      cp ${pathdfsin}/${var}_DFS4.3_${year}.nc ${var}_dfs4.3_${year}.nc
      ncks -A -v time ${var}_eraint_${year}.nc ${var}_dfs4.3_${year}.nc
      case $var in
        'u10'|'v10'|'t2'|'q2') cdo setgrid,r320x161 ${var}_dfs4.3_${year}.nc ${var}_dfs4.3_${year}_bis.nc ;;
        'qsw'|'qlw'|'snow'|'precip') cdo setgrid,r192x94 ${var}_dfs4.3_${year}.nc ${var}_dfs4.3_${year}_bis.nc ;;
      esac
      ncks -O -x -v lat_2,lon_2 ${var}_dfs4.3_${year}_bis.nc ${var}_dfs4.3_${year}.nc
      rm -f ${var}_dfs4.3_${year}_bis.nc
      if [[ $dfs2era == T ]] ; then
        cdo remapbic,r240x121 ${var}_dfs4.3_${year}.nc ${var}_dfs4.3_${year}_grideraint.nc
        cdo invertlat ${var}_dfs4.3_${year}_grideraint.nc ${var}_dfs4.3_${year}_grideraint_bis.nc
        rm -f ${var}_dfs4.3_${year}.nc ${var}_dfs4.3_${year}_grideraint.nc 
        mv ${var}_dfs4.3_${year}_grideraint_bis.nc ${var}_dfs4.3_gridera_${year}.nc 
        cdo sub ${var}_eraint_${year}.nc ${var}_dfs4.3_gridera_${year}.nc ${var}_eraint-dfs4.3_${year}.nc
      else
        case $var in
          'u10'|'v10'|'t2'|'q2') cdo remapbic,r320x161 ${var}_eraint_${year}.nc ${var}_eraint_griddfs_${year}.nc ;;
          'qsw'|'qlw'|'snow'|'precip') cdo remapbic,r192x94 ${var}_eraint_${year}.nc ${var}_eraint_griddfs_${year}.nc ;;
        esac
        rm -f ${var}_eraint_${year}.nc 
        cdo sub ${var}_dfs4.3_${year}.nc ${var}_eraint_griddfs_${year}.nc ${var}_dfs4.3-eraint_${year}.nc
      fi
    done
  fi
  if [[ $ano == T ]] ; then
    length=30
    if [[ $dfs2era == T ]] ; then 
      ncea -O -n $((${yearf}-${year0}+1)),4,1 ${var}_dfs4.3_gridera_${year0}.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim.nc
      ncea -O -n $((${yearf}-${year0}+1)),4,1 ${var}_eraint_${year0}.nc ${var}_eraint_${year0}-${yearf}_clim.nc
      ncrcat -O ${var}_dfs4.3_gridera_${year0}-${yearf}_clim.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_bis.nc
      ncrcat -O ${var}_eraint_${year0}-${yearf}_clim.nc ${var}_eraint_${year0}-${yearf}_clim.nc ${var}_eraint_${year0}-${yearf}_clim_bis.nc
      cdo runmean,${length} ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_bis.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed.nc
      ncks -O -d time,$(($nstep+1)),$(($nstep+$length/2)) ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_1.nc
      ncks -O -d time,$(($length/2+1)),$nstep ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_2.nc
      ncrcat -O ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_1.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_2.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim.nc
      rm -f ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_bis.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_1.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim_smoothed_2.nc
      cdo runmean,${length} ${var}_eraint_${year0}-${yearf}_clim_bis.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed.nc
      ncks -O -d time,$(($nstep+1)),$(($nstep+$length/2)) ${var}_eraint_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed_1.nc
      ncks -O -d time,$(($length/2+1)),$nstep ${var}_eraint_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed_2.nc
      ncrcat -O ${var}_eraint_${year0}-${yearf}_clim_smoothed_1.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed_2.nc ${var}_eraint_${year0}-${yearf}_clim.nc
      rm -f ${var}_eraint_${year0}-${yearf}_clim_bis.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed_1.nc ${var}_eraint_${year0}-${yearf}_clim_smoothed_2.nc
      for ((year=$year0;year<=$yearf;year++)) ; do
        cdo sub ${var}_eraint_${year}.nc ${var}_eraint_${year0}-${yearf}_clim.nc ${var}_ano_eraint_${year}.nc
        cdo sub ${var}_dfs4.3_gridera_${year}.nc ${var}_dfs4.3_gridera_${year0}-${yearf}_clim.nc ${var}_ano_dfs4.3_gridera_${year}.nc
        cdo sub ${var}_ano_eraint_${year}.nc ${var}_ano_dfs4.3_gridera_${year}.nc ${var}_ano_eraint-dfs4.3_${year}.nc
        rm -f ${var}_eraint_${year}.nc ${var}_dfs4.3_gridera_${year}.nc ${var}_ano_eraint_${year}.nc ${var}_ano_dfs4.3_gridera_${year}.nc
      done
    else
      ncea -O -n $((${yearf}-${year0}+1)),4,1 ${var}_dfs4.3_${year0}.nc ${var}_dfs4.3_${year0}-${yearf}_clim.nc
      ncea -O -n $((${yearf}-${year0}+1)),4,1 ${var}_eraint_griddfs_${year0}.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim.nc
      ncrcat -O ${var}_dfs4.3_${year0}-${yearf}_clim.nc ${var}_dfs4.3_${year0}-${yearf}_clim.nc ${var}_dfs4.3_${year0}-${yearf}_clim_bis.nc
      ncrcat -O ${var}_eraint_griddfs_${year0}-${yearf}_clim.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_bis.nc
      cdo runmean,${length} ${var}_dfs4.3_${year0}-${yearf}_clim_bis.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed.nc
      ncks -O -d time,$(($nstep+1)),$(($nstep+$length/2)) ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_1.nc
      ncks -O -d time,$(($length/2+1)),$nstep ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_2.nc
      ncrcat -O ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_1.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_2.nc ${var}_dfs4.3_${year0}-${yearf}_clim.nc
      rm -f ${var}_dfs4.3_${year0}-${yearf}_clim_bis.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_1.nc ${var}_dfs4.3_${year0}-${yearf}_clim_smoothed_2.nc
      cdo runmean,${length} ${var}_eraint_griddfs_${year0}-${yearf}_clim_bis.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed.nc
      ncks -O -d time,$(($nstep+1)),$(($nstep+$length/2)) ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_1.nc
      ncks -O -d time,$(($length/2+1)),$nstep ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_2.nc
      ncrcat -O ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_1.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_2.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim.nc
      rm -f ${var}_eraint_griddfs_${year0}-${yearf}_clim_bis.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_1.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim_smoothed_2.nc
      for ((year=$year0;year<=$yearf;year++)) ; do
        cdo sub ${var}_eraint_griddfs_${year}.nc ${var}_eraint_griddfs_${year0}-${yearf}_clim.nc ${var}_ano_eraint_griddfs_${year}.nc
        cdo sub ${var}_dfs4.3_${year}.nc ${var}_dfs4.3_${year0}-${yearf}_clim.nc ${var}_ano_dfs4.3_${year}.nc
        cdo sub ${var}_ano_dfs4.3_${year}.nc ${var}_ano_eraint_griddfs_${year}.nc ${var}_ano_dfs4.3-eraint_${year}.nc
        rm -f ${var}_eraint_griddfs_${year}.nc ${var}_dfs4.3_${year}.nc ${var}_ano_eraint_griddfs_${year}.nc ${var}_ano_dfs4.3_${year}.nc
      done
    fi
  fi
  if [[ $reorg == T ]] ; then
    for ((jt=1;jt<=$nstep;jt++)) ; do
      ncrcat -O  -d time,$((jt-1)),,$nstep -n $((yearf-year0+1)),4,1 ${var}_${wih}${dif}_${year0}.nc ${var}_${wih}${dif}_${year0}-${yearf}_$jt.nc
    done
    mkdir -p ${wih}${dir0} 
    mv ${var}_${wih}${dif}_* ${wih}${dir0}/.
  fi
  if [[ $raw == T && $ano == F ]] ; then
    for ((year=$year0;year<=$yearf;year++)) ; do
      if [[ $dfs2era == T ]] ; then
        rm -f ${var}_eraint_${year}.nc ${var}_dfs4.3_gridera_${year}.nc
      else
        rm -f ${var}_eraint_griddfs_${year}.nc ${var}_dfs4.3_${year}.nc
      fi
    done
  fi

  if [[ $monmean == T ]] ; then
    jt0=1
    for ((mon=1;mon<=12;mon++)) ; do
      case $mon in 
        1|3|5|7|8|10|12) ndays=31 ;;
        4|6|9|11) ndays=30 ;;    
        2) ndays=28 ;;
      esac
      lstfiles=""
      case $nstep in 
        1460) ntimes=$((ndays*4+jt0-1)) ;;
        365) ntimes=$((ndays+jt0-1)) ;;
        12) ntimes=1 ;;
      esac
      for ((jt=$jt0;jt<=$ntimes;jt++)) ;do
        lstfiles=$lstfiles" "${wih}${dir0}/${var}_${wih}${dif}_${year0}-${yearf}_$jt.nc
      done
      ncea -O $lstfiles ${wih}${dir0}/${var}_${wih}${dif}_${year0}-${yearf}_mon$(printf "%02d" ${mon}).nc
      case $nstep in
        1460) jt0=$((${jt0}+ndays*4)) ;;
        365) jt0=$((${jt0}+ndays)) ;;
        12) jt0=$((${jt0}+1)) ;;
      esac
    done
  fi
done

if [[ $pickup1 == T ]] ; then
  if [[ $monmean == T ]] ; then
    dirpert=perturb1_${dir0}_mon
    nstep=12
  else
    dirpert=perturb1_${dir0}
  fi
  mkdir -p $dirpert
  RANGE=$((${yearf}-${year0}+1))
  for ((jt=1;jt<=$nstep;jt++)) ; do
    for memb in ${lstmbs[@]} ; do
      for ((year=$year1;year<=$year2;year++)) ; do
        number=$((RANDOM%${RANGE}))
        for var in ${lstvars[@]} ; do
          if [[ $monmean == T ]] ; then
            filein=${var}_${wih}${dif}_${year0}-${yearf}_mon$(printf "%02d" ${jt}).nc
          else
            filein=${var}_${wih}${dif}_${year0}-${yearf}_$jt.nc
          fi
          ncks -O -d time,$number ${wih}${dir0}/${filein} ${dirpert}/${var}_fc${memb}_${year}_$(printf "%04d" $jt).nc
        done
      done
    done
  done
fi

if [[ $pickup2 == T ]] ; then
  mkdir -p perturb2_${dir0}
  RANGE=$((${yearf}-${year0}+1))
  for ((jt=1;jt<=$nstep;jt++)) ; do
    for memb in ${lstmbs[@]} ; do
      for ((year=$year1;year<=$year2;year++)) ; do
        for ((jlaunch=1;jlaunch<=2;jlaunch++)) ; do
          number=$((RANDOM%${RANGE}))
          for var in ${lstvars[@]} ; do
            ncks -O -d time,$number ${wih}${dir0}/${var}_${wih}${dif}_${year0}-${yearf}_$jt.nc perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt)_$jlaunch.nc
          done
        done
        for var in ${lstvars[@]} ; do
          ncea -O perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt)_1.nc perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt)_2.nc perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt).nc
          rm -f perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt)_1.nc perturb2_${dir0}/${var}_fc${memb}_${year}_$(printf "%04d" $jt)_2.nc
        done
      done
    done
  done
fi

if [[ $pickup1 == T || $pickup2 == T ]] ; then
  lstdirs=""
  if [[ $pickup1 == T ]]  ; then
    if [[ $monmean == T ]] ; then
      lstdirs=$lstdirs" "perturb1_${dir0}_mon
    else
      lstdirs=$lstdirs" "perturb1_${dir0}
    fi
  fi
  if [[ $pickup2 == T ]]  ; then
    lstdirs=$lstdirs" "perturb2_${dir0}
  fi
  for dir in $lstdirs ; do
  for memb in ${lstmbs[@]} ; do
    for ((year=$year1;year<=$year2;year++)) ; do
      for var in ${lstvars[@]} ; do
        ncrcat -O -n $nstep,4,1 ${dir}/${var}_fc${memb}_${year}_0001.nc ${dir}/${var}_fc${memb}_${year}.nc
        rm -f ${dir}/${var}_fc${memb}_${year}_*.nc
        if [[ $monmean == T ]] ; then
          cdo settaxis,${year}-01-15,12:00,1mon ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_bis.nc
          rm ${dir}/${var}_fc${memb}_${year}.nc 
          mv ${dir}/${var}_fc${memb}_${year}_bis.nc ${dir}/${var}_fc${memb}_${year}.nc
        fi
        if [[ $dfs2era == T && $monmean == F ]] ; then
          case $year in 
            1980|1984|1988|1992|1996|2000|2004|2008|2012|2016|2020)
            case $nstep in
             1460)
              ncks -O -d time,0,232 ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_1.nc
              ncks -O -d time,229,232 ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_2.nc
              ncks -O -d time,233, ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_3.nc
              ;;
             365)
              ncks -O -d time,0,58 ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_1.nc
              ncks -O -d time,58 ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_2.nc
              ncks -O -d time,59, ${dir}/${var}_fc${memb}_${year}.nc ${dir}/${var}_fc${memb}_${year}_3.nc
              ;;
            esac
            ncrcat -O ${dir}/${var}_fc${memb}_${year}_1.nc ${dir}/${var}_fc${memb}_${year}_2.nc ${dir}/${var}_fc${memb}_${year}_3.nc ${dir}/${var}_fc${memb}_${year}.nc
            rm -f ${dir}/${var}_fc${memb}_${year}_1.nc ${dir}/${var}_fc${memb}_${year}_2.nc ${dir}/${var}_fc${memb}_${year}_3.nc
          esac
        fi
      done
    done
  done
  done
fi
     
if [[ $monmean == T ]] ; then
  for memb in ${lstmbs[@]} ; do
    for var in ${lstvars[@]} ; do
      ncrcat -O -n $((${year2}-${year1}+1)),4,1 perturb1_${dir0}_mon/${var}_fc${memb}_${year1}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}.nc
      cdo inttime,${year1}-01-15,12:00,6hour perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}_6hourly.nc
      rm -f perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}.nc
      cdo splityear perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}_6hourly.nc perturb1_${dir0}_mon/${var}_fc${memb}_
      rm -f perturb1_${dir0}_mon/${var}_fc${memb}_${year1}-${year2}_6hourly.nc
      if [[ $dfs2era == F ]] ; then
        lstyears=( 1960 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020 )
        for year in ${lstyears[@]} ; do
          if [[ -e perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc ]] ; then 
            case $nstep in
             1460)
              ncks -O -d time,0,232 perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_1.nc
              ncks -O -d time,237, perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_2.nc
              ;;
             365)
              ncks -O -d time,0,58 perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_1.nc
              ncks -O -d time,60, perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_2.nc
              ;;
            esac
            ncrcat -O perturb1_${dir0}_mon/${var}_fc${memb}_${year}_1.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_2.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}.nc
            rm -f perturb1_${dir0}_mon/${var}_fc${memb}_${year}_1.nc perturb1_${dir0}_mon/${var}_fc${memb}_${year}_2.nc  
          fi
        done
      fi
    done
  done
fi