[ncl-talk] how can I mask ocean data from a 4D variable using 2D oro from atmos.nc - any alternatives?
Dennis Shea
shea at ucar.edu
Tue Nov 24 08:43:04 MST 2015
Well, the source mask file is 1x1 but can still be used to generate a
nominal a 0.5x0.5 mask.
True ... it is not a perfect match but it may be 'good enough'.
===
FYI only: Attached is a 0.1666667 degree land-sea make from the CERES project.
Good luck
On Tue, Nov 24, 2015 at 7:46 AM, Ruksana Abedin
<ruksana.abedin at gmail.com> wrote:
> Hi,
>
> Thank you for your feedback. I have made and ploted the landsea mask given
> at exampl 5. But, again, In example 5, it says that the mask will be
> suitable for 1x1 resolution and not for finer resolution. The climate model
> data, I am using, has .5x.5 resolution. can I use the mask for this model
> then?
>
> Thanks for your time.
>
> Best regards,
> Ruksana
>
> On Fri, Nov 20, 2015 at 4:04 PM, Dennis Shea <shea at ucar.edu> wrote:
>>
>> The 'atmos.nc' contains
>>
>> Variable: oro
>> Number of Dimensions: 2
>> Dimensions and sizes: [lat | 64] x [lon | 128]
>>
>> Your data set has dimensions
>>
>> x_2 = 209 ;
>> y_2 = 146 ;
>>
>> Two completely different resolutions ..... The 'mask' function
>> documentation states that the array sizes must match
>> http://www.ncl.ucar.edu/Document/Functions/Built-in/mask.shtml
>>
>> Obviously, they don't match ... hence the error message.
>> fatal:mask: dimension sizes of parameter 0 and parameter 1 do not
>> match
>> =====
>>
>> DId you look at the 'Applications' page? You can create a reasonably
>> good mask for your data sets via
>>
>> http://www.ncl.ucar.edu/Applications/mask.shtml
>> See Example 5
>>
>> Good luck
>>
>> On Fri, Nov 20, 2015 at 6:59 AM, Ruksana Abedin
>> <ruksana.abedin at gmail.com> wrote:
>> > 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
>> >
>> >
>> > _______________________________________________
>> > ncl-talk mailing list
>> > ncl-talk at ucar.edu
>> > List instructions, subscriber options, unsubscribe:
>> > http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>> >
>
>
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