SNAP documentation

KOPRI

Om has decided to take this over, which is why these notes are incomplete.

The KOPRI files can be found below /group_workspaces/jasmin/snap/kopri/phase1/. In here there are currently 15 directories, all named used dates in the form YYYYMMDD. These include the 5 Northern starting dates (23 & 28 Dec, 2, 7 & 12 Jan). And for each of these dates, one directory a day before and one directory a day after.

And in each directory there's two types of files

  • surface variable in the fgb*.nc files (lat=94, lon=192)
  • variables on pressure level in the pgb* files (lat=73, lon=144)
which seem to represent one timestep. WE ONLY SEEM TO HAVE ONE ENSEMBLE IN EACH DIRECTORY?

Putting the data into one file

For each experiment the data is put into one file with the script /home/users/stringer/snap/bin/conformKopri.scr, whose only argument is the directory with the data, e.g. 

./conformKopri.scr /group_workspaces/jasmin/snap/kopri/phase1/20130103
to create kopri20130103.nc. This script uses the NCO tools to do the following

  • Loop across each hour
    • Copy the fgb* files into work directory, /home/users/stringer/snap/data
    • Some files have the extension _ave6h to the variable names, some don't. So all the _ave6h extensions are removed
    • Copies the pgb* files into work directory
    • The first pgb* file is missing the VAR_154_2_ISBL variable. I've written the /home/users/stringer/snap/code/insertFillValue.cpp code to help create /home/users/stringer/snap/fillData/VAR_154_2_ISBL.nc, which is one entry of VAR_154_2_ISBL containing only the _FillValue. This is added to the first pgb* file, so that every pgb* file has the VAR_154_2_ISBL variable
    • Later almost all the variables will have the time dimension added to them. However, we don't want the time dimension adding to lv_DBLY2_l0 and lv_DBLY2_l1 - so these are pulled into their own files (the fbg*noTime_tmp.nc files).
    • The no time variables lv_DBLY2_l0 and lv_DBLY2_l1 are removed from the fgb* files.
    • fgbYYYYMMDD_tmp.nc and pgbYYYYMMDD_tmp.nc are put together into pgbYYYYMMDD_tmp.nc.
    • The time is determined from the forcecast_time attribute, and added to pgbYYYYMMDD_tmp.nc as both a value and dimension for all the variables in here (although it's not done for variables with names matching the dimension names).
    • Add in lv_DBLY2_l0 and lv_DBLY2_l1 to pgbYYYYMMDD_tmp.nc.
  • Put all the pgbYYYYMMDD_tmp.nc files into one file, kopr_YYYYMMDD_01.nc, where the date now comes from the directory name, which is the start date. At this stage all other files are deleted.
  • Remove the forecast_time and forecast_time_units attributes from this file as they only refer to the first time - and we know have lots of times.
  • Add the time attributes
  • Rename the variables according to the table below.

Renaming variables

Where possible the variable names should be consistent with the names used in ERA-Interim data.

Old variable nameOld long_name New variable nameNew long_name
PRES_2_SFCPressure SPSurface pressure
PRES_2_MSLPressure MSLMean sea-level pressure
HGT_2_SFCGeopotential height ERAI has geopotential but not geopotential height?
HGT_2_ISBLGeopotential height ERAI has geopotential but not geopotential height?
TMP_2_ISBLTemp.
U_GRD_2_ISBLu wind
V_GRD_2_ISBLv wind
V_VEL_2_ISBLPressure vertical velocity ??
ABS_V_2_ISBLAbsolute vorticity
SPFH_2_ISBLSpecific humidity
RH_2_ISBLRelative humidity
P_WAT_2_EATMPrecipitable water
MIXHT_2_EATMMixed layer depth
TTHDP_2_EATMTransient thermocline depth
MTHD_2_EATMMain thermocline depth
C_WAT_2_EATMCloud water
VAR_77_2_EATMUnknown Variable Name
lv_ISBL2isobaric level
lat_2latitude latitudelatitude
lon_2longitude longitudelongitude
VAR_154_2_ISBLUnknown Variable Name
ALBDO_98_SFCAlbedo
BRTMP_98_SFCBrightness temperature
ICE_C_98_SFCIce concentration (ice=1;no ice=0)
LAND_98_SFCLand-sea mask (land=1;sea=0)
LHTFL_98_SFCLatent heat flux
PRATE_98_SFCPrecipitation rate
PRES_98_HCBLPressure ??
PRES_98_HCTLPressure ??
PRES_98_LCBLPressure ??
PRES_98_LCTLPressure ??
PRES_98_MCBLPressure ??
PRES_98_MCTLPressure ??
PRES_98_SFCPressure ??
P_WAT_98_EATMPrecipitable water
SFC_R_98_SFCSurface roughness
SHTFL_98_SFCSensible heat flux
SPF_H_98_HTGLSpecific humidity
SRWEQ_98_SFCSnowfall rate water equivalent.
TMP_98_DBLYTemperature
TMP_98_HCTLTemperature
TMP_98_HTGLTemperature
TMP_98_LCTLTemperature
TMP_98_MCTLTemperature
TMP_98_SFCTemperature
T_CDC_98_EATMTotal cloud cover
T_CDC_98_HCYTotal cloud cover
T_CDC_98_LCYTotal cloud cover
T_CDC_98_MCYTotal cloud cover
T_MAX_98_HTGLMaximum temperature
T_MIN_98_HTGLMinimum temperature
U_FLX_98_SFCMomentum flux, u component
U_GRD_98_HTGLu-component of wind
VAR_144_98_DBLYUnknown Variable Name
VAR_145_98_SFCUnknown Variable Name
VAR_146_98_SFCUnknown Variable Name
VAR_147_98_SFCUnknown Variable Name
VAR_148_98_SFCUnknown Variable Name
VAR_155_98_SFCUnknown Variable Name
VAR_170_98_SFCUnknown Variable Name
VAR_171_98_SFCUnknown Variable Name
VAR_180_98_SFCUnknown Variable Name
VAR_190_98_SFCUnknown Variable Name
VAR_202_98_EATMUnknown Variable Name
VAR_203_98_EATMUnknown Variable Name
VAR_204_98_NTATUnknown Variable Name
VAR_204_98_SFCUnknown Variable Name
VAR_205_98_SFCUnknown Variable Name
VAR_211_98_NTATUnknown Variable Name
VAR_211_98_SFCUnknown Variable Name
VAR_212_98_NTATUnknown Variable Name
VAR_212_98_SFCUnknown Variable Name
VAR_214_98_SFCUnknown Variable Name
VAR_221_98_SFCUnknown Variable Name
VAR_223_98_SFCUnknown Variable Name
VAR_225_98_SFCUnknown Variable Name
VAR_226_98_SFCUnknown Variable Name
VAR_229_98_SFCUnknown Variable Name
VAR_230_98_SFCUnknown Variable Name
VAR_234_98_SFCUnknown Variable Name
VAR_236_98_SFCUnknown Variable Name
VEG_98_SFCVegetation
V_FLX_98_SFCMomentum flux, v component
V_GRD_98_HTGLv-component of wind
WATR_98_SFCWater runoff
WEASD_98_SFCWater equivalent of accum. snow depth
lv_DBLY2_l0layer between two depths below land surface
lv_DBLY2_l1layer between two depths below land surface

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