[ncl-talk] how can I mask ocean data from a 4D variable using 2D oro from atmos.nc - any alternatives?

Ruksana Abedin ruksana.abedin at gmail.com
Fri Nov 20 06:59:00 MST 2015


Hi,

I need to mask the ocean data from my model data of temperature to see
temperatures on land only and compare that with APHRODITES later.

I tried to mask with oro from atmos file given at ncl website. Problem is
Field16 (temperature) is 4D and oro is 2D. What can be solution for this
problem? Can I alternatively use any other mask array for this case?

Please help me to solve this problem.

Current output map is attached.

Giving below the file details:

ncdump -h wah2_sas_1985_2007.part.seasmean.temp.nc

netcdf wah2_sas_1985_2007.part.seasmean.temp {
dimensions:
        x = 209 ;
        y = 145 ;
        x_2 = 209 ;
        y_2 = 146 ;
        z0 = 1 ;
        z1 = 1 ;
        z2 = 1 ;
        time0 = UNLIMITED ; // (1 currently)
variables:
        float global_longitude0(y, x) ;
                global_longitude0:standard_name = "longitude" ;
                global_longitude0:long_name = "longitude" ;
                global_longitude0:units = "degrees_east" ;
                global_longitude0:_CoordinateAxisType = "Lon" ;
        float global_latitude0(y, x) ;
                global_latitude0:standard_name = "latitude" ;
                global_latitude0:long_name = "latitude" ;
                global_latitude0:units = "degrees_north" ;
                global_latitude0:_CoordinateAxisType = "Lat" ;
        float global_longitude1(y_2, x_2) ;
                global_longitude1:standard_name = "longitude" ;
                global_longitude1:long_name = "longitude" ;
                global_longitude1:units = "degrees_east" ;
                global_longitude1:_CoordinateAxisType = "Lon" ;
        float global_latitude1(y_2, x_2) ;
                global_latitude1:standard_name = "latitude" ;
                global_latitude1:long_name = "latitude" ;
                global_latitude1:units = "degrees_north" ;
                global_latitude1:_CoordinateAxisType = "Lat" ;
        float z0(z0) ;
                z0:standard_name = "height" ;
                z0:units = "m" ;
                z0:positive = "up" ;
                z0:axis = "Z" ;
        float z1(z1) ;
                z1:standard_name = "height" ;
                z1:units = "m" ;
                z1:positive = "up" ;
                z1:axis = "Z" ;
        float z2(z2) ;
                z2:standard_name = "air_pressure" ;
                z2:units = "hPa" ;
                z2:positive = "down" ;
                z2:axis = "Z" ;
        double time0(time0) ;
                time0:standard_name = "time" ;
                time0:units = "days since 1959-12-01 00:00:00" ;
                time0:calendar = "360_day" ;
        float field48(time0, z0, y, x) ;
                field48:standard_name = "eastward_wind" ;
                field48:long_name = "10 METRE WIND U-COMP" ;
                field48:units = "m s-1" ;
                field48:coordinates = "global_longitude0 global_latitude0" ;
                field48:_FillValue = -1.073742e+09f ;
                field48:stash_item = "225" ;
                field48:stash_section = "3" ;
                field48:field_code = "56" ;
                field48:cell_method = "time: mean " ;
        float field49(time0, z0, y, x) ;
                field49:standard_name = "northward_wind" ;
                field49:long_name = "10 METRE WIND V-COMP" ;
                field49:units = "m s-1" ;
                field49:coordinates = "global_longitude0 global_latitude0" ;
                field49:_FillValue = -1.073742e+09f ;
                field49:stash_item = "226" ;
                field49:stash_section = "3" ;
                field49:field_code = "57" ;
                field49:cell_method = "time: mean " ;
        float field16(time0, z0, y_2, x_2) ;
                field16:standard_name = "air_temperature" ;
                field16:long_name = "TEMPERATURE AT 1.5M" ;
                field16:units = "K" ;
                field16:coordinates = "global_longitude1 global_latitude1" ;
                field16:_FillValue = -1.073742e+09f ;
                field16:stash_item = "236" ;
                field16:stash_section = "3" ;
                field16:field_code = "16" ;
                field16:cell_method = "time: maximum " ;
        float field16_1(time0, z0, y_2, x_2) ;
                field16_1:standard_name = "air_temperature" ;
                field16_1:long_name = "TEMPERATURE AT 1.5M" ;
                field16_1:units = "K" ;
                field16_1:coordinates = "global_longitude1
global_latitude1" ;
                field16_1:_FillValue = -1.073742e+09f ;
                field16_1:stash_item = "236" ;
                field16_1:stash_section = "3" ;
                field16_1:field_code = "16" ;
                field16_1:cell_method = "time: minimum " ;
        float field90(time0, z1, y_2, x_2) ;
                field90:standard_name = "precipitation_flux" ;
                field90:long_name = "TOTAL PRECIPITATION RATE KG/M2/S" ;
                field90:units = "kg m-2 s-1" ;
                field90:coordinates = "global_longitude1 global_latitude1" ;
                field90:_FillValue = -1.073742e+09f ;
                field90:stash_item = "216" ;
                field90:stash_section = "5" ;
                field90:field_code = "90" ;
                field90:cell_method = "time: mean " ;
        float field93(time0, z1, y_2, x_2) ;
                field93:standard_name = "snowfall_amount" ;
                field93:long_name = "SNOW MASS AFTER HYDROLOGY KG/M2" ;
                field93:units = "kg m-2" ;
                field93:coordinates = "global_longitude1 global_latitude1" ;
                field93:_FillValue = -1.073742e+09f ;
                field93:stash_item = "23" ;
                field93:stash_section = "8" ;
                field93:field_code = "93" ;
                field93:cell_method = "time: mean " ;
        float field1532(time0, z1, y_2, x_2) ;
                field1532:standard_name = "surface_runoff_flux" ;
                field1532:long_name = "SURFACE RUNOFF RATE KG/M2/S" ;
                field1532:units = "kg m-2 s-1" ;
                field1532:coordinates = "global_longitude1
global_latitude1" ;
                field1532:_FillValue = -1.073742e+09f ;
                field1532:stash_item = "234" ;
                field1532:stash_section = "8" ;
                field1532:field_code = "1532" ;
                field1532:cell_method = "time: mean " ;
        float field1(time0, z2, y_2, x_2) ;
                field1:standard_name = "geopotential_height" ;
                field1:long_name = "GEOPOTENTIAL HEIGHT: PRESSURE LEVELS" ;
                field1:units = "m" ;
                field1:coordinates = "global_longitude1 global_latitude1" ;
                field1:_FillValue = -1.073742e+09f ;
                field1:stash_item = "202" ;
                field1:stash_section = "16" ;
                field1:field_code = "1" ;
                field1:cell_method = "time: mean " ;

// global attributes:
                :CDI = "Climate Data Interface version 1.6.0 (
http://code.zmaw.de/projects/cdi)" ;
                :Conventions = "CF-1.3" ;
                :history = "Tue Nov 10 15:58:38 2015: cdo timmean
-selmon,6/9 wah2_sas_1985_2007.part.nc
wah2_sas_1985_2007.part.seasmean.temp.nc\n",
                        "Mon Nov 09 12:02:27 2015: cdo mergetime
wah2_sas_ga.pdi.1985.nc wah2_sas_1987_p2.nc wah2_sas_ga.pdj.1991.nc
wah2_sas_ga.pdj.1992.nc wah2_sas_1994_p2.nc wah2_sas_ga.pdj.1995.nc
wah2_sas_ga.pdj.1996.nc wah2_sas_ga.pdj.1997.nc wah2_sas_ga.pdj.1998.nc
wah2_sas_ga.pdk.2000.nc wah2_sas_ga.pdk.2001.nc wah2_sas_ga.pdk.2002.nc
wah2_sas_ga.pdk.2003.nc wah2_sas_ga.pdk.2004.nc wah2_sas_ga.pdk.2005.nc
wah2_sas_ga.pdk.2006.nc wah2_sas_1985_2007.part.nc\n",
                        "Fri Oct 23 12:59:32 2015: cdo mergetime
0049ga.pdk6dec.nc 0049ga.pdk7jan.nc 0049ga.pdk7feb.nc 0049ga.pdk7mar.nc
0049ga.pdk7apr.nc 0049ga.pdk7may.nc 0049ga.pdk7jun.nc 0049ga.pdk7jul.nc
0049ga.pdk7aug.nc 0049ga.pdk7sep.nc 0049ga.pdk7oct.nc 0049ga.pdk7nov.nc
wah2_sas_ga.pdk.2006.nc" ;
                :alpham = 0.5f ;
                :CDO = "Climate Data Operators version 1.6.0 (
http://code.zmaw.de/projects/cdo)" ;


while,

Variable: oro
Type: float
Total Size: 32768 bytes
            8192 values
Number of Dimensions: 2
Dimensions and sizes:   [lat | 64] x [lon | 128]
Coordinates:
            lat: [-87.8638..87.8638]
            lon: [ 0..357.1875]
Number Of Attributes: 2
  time :         791
  long_name :   ocean (0), land (1), sea ice (2) flag
The script I used is:

;*********************************
;
;**********************************
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/shea_util.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/popRemap.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/contrib/calendar_decode2.ncl"
;************************************************

begin

; read in data

f=addfile ("/ouce-home/students/rege1218/WAH2_SAS_Results_1985_2011/
wah2_sas_1985_2007.part.seasmean.temp.nc", "r");
f1=addfile("/ouce-home/students/rege1218/WAH2_SAS_Results_1985_2011/atmos.nc
","r")

temp_mod1 = f->field16
temp_mod1 = temp_mod1 - 273.15 ; Convert Kelvin -> Celsius

temp_mod2 = f->field16_1
temp_mod2 = temp_mod2 - 273.15 ; Convert Kelvin -> Celsius

temp_mod = (temp_mod1+temp_mod2)/2
time = f->time0
lat2d = f->global_latitude1  ;0
lon2d = f->global_longitude1 ;0
;lat = f->latitude1
;lon = f->longitude1

temp_mod!0 = "time"
temp_mod!1 = "surface"
temp_mod!2 = "lat"
temp_mod!3 = "lon"
temp_mod at units = "(C)"       ; Change units to reflect.
temp_mod at lat2d = lat2d
temp_mod at lon2d = lon2d

temp_mod = temp_mod(0,0,:,:)
oro = f1->ORO(0,:,:)

printVarSummary(temp_mod)
printVarSummary(oro)

;***********************************************************
; use mask function to mask out land then ocean data
; ocean=0, land=1, sea_ice=2
;***********************************************************
land_only = temp_mod        ;trick to keep cv's and atts
ocean_only = temp_mod


land_only = mask(temp_mod, oro,1)     ; Return the values of temp_mod where
oro=1
ocean_only = mask(temp_mod, oro,0)    ; Return the values of temp_mod where
oro=0

;***********************************************************
; create plots
;***********************************************************

  wks = gsn_open_wks("eps","temp1")
  gsn_define_colormap(wks,"hotcolr_19lev")      ; choose colormap
  ;gsn_reverse_colormap(wks)
  res                          = True
  res at cnFillOn                 = True                 ; turn on color
  res at cnLinesOn                = False             ; turn off contour lines
  res at cnLevelSpacingF          = 0.10              ; contour interval
  res at cnFillDrawOrder          = "PreDraw"         ; draw contours first
  res at lbLabelStride            = 2                 ; stride on label bar
  res at gsnSpreadColors          = True              ; use full colormap
  res at gsnSpreadColorEnd        = -3                ; -3 don't use land color
  res at gsnAddCyclic             = False             ; regional data
  res at gsnLeftString            = ""
  res at tiMainString             = ""
  res at gsnRightString           = ""
  ;res at mpProjection            = "LambertConformal"
  ;res at gsnMaskLambertConformal = True
  res at mpMaxLatF                = 60;max(lat)  ; zoom in on region
  res at mpMinLatF                = -30;min(lat)
  res at mpMinLonF                = 0;min(lon)
  res at mpMaxLonF                = 130; max(lon)
  res at mpCenterLonF = 10                          ; def is zero
  res at mpLandFillColor          = "Transparent"
  res at cnLevelSelectionMode= "ManualLevels"
  res at cnMinLevelValF      =  -4.00
  res at cnMaxLevelValF      =  48.00 ;2
  res at cnLevelSpacingF     = 2 ;2
  res at lbLabelAutoStride   = True
  temp_mod at _FillValue    = 0.0
  temp_mod at _FillValue    = -999

  plot_test = gsn_csm_contour_map(wks,land_only(0,0,:,:),res)


end

error I got:

fatal:mask: dimension sizes  of parameter 0 and parameter 1 do not match
fatal:Execute: Error occurred at or near line 54 in file
Correctred_wah2_sas_seasonalmean_temp_1985_2007_part.ncl


Thank you,
Ruksana
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