obtain fields in low resolutions by area_hi2lores_Wrap

From: Yi-Chih Huang <dscpln_at_nyahnyahspammersnyahnyah>
Date: Mon Dec 09 2013 - 00:37:53 MST

Hello,

    I am trying to use area_hi2lores_Wrap to obtain the precipitation and
wind fields in different low resolutions. I used the same commands; but
the patterns of precipitation changed dramatically; while the wind fields
remained the same. When "pLo = area_hi2lores_Wrap (pcp&lon,pcp&lat, pcp ,
True, 1, LON, LAT, False)" was commented, there was no such a warning
message as "Data either does not contain a valid latitude coordinate array
or doesn't contain one at all." I attached the commands, output of
printVarSummary, warning message, and the script as follows. Could anyone
tell me what was wrong with precipitation field in area_hi2lores_Wrap?

    Thanks much,

              Yi-Chih

#####
  LON = fspan( 31.25,158.75, 52)
  LAT = fspan(-28.75, 28.75, 24)
  opt = True
  opt@critpc = 50 ; require only 50% of the values to be
precent
  pLo = area_hi2lores_Wrap (pcp&lon,pcp&lat, pcp , True, 1, LON, LAT,
False)

  LON := fspan( 30.,160., 261)
  LAT := fspan(-30., 30., 121)
  opt = True
  opt@critpc = 50 ; require only 50% of the values to be
precent
  uLo = area_hi2lores_Wrap (uwnd&lon, uwnd&lat, uwnd, True, 1, LON, LAT,
False)
  vLo = area_hi2lores_Wrap (vwnd&lon, vwnd&lat, vwnd, True, 1, LON, LAT,
False)
#####
Variable: uLo
Type: float
Total Size: 126324 bytes
            31581 values
Number of Dimensions: 2
Dimensions and sizes: [LAT | 121] x [LON | 261]
Coordinates:
            LAT: [-30..30]
            LON: [30..160]
Number Of Attributes: 13
  DataFreq : Monthly
  average_op_ncl : dim_avg_n over dimension(s): year
  lv_ISBL1 : 850
  center : US National Weather Service - NCEP (WMC)
  long_name : u-component of wind
  units : m/s
  level_indicator : 100
  gds_grid_type : 0
  parameter_table_version : 2
  parameter_number : 33
  model : Climate Data Assimilation System (CDAS)
  initial_time : 02/05/2006 (00:00)
  _FillValue : 1e+20

Variable: pLo
Type: float
Total Size: 4992 bytes
            1248 values
Number of Dimensions: 2
Dimensions and sizes: [lat | 24] x [lon | 52]
Coordinates:
            lat: [-28.75..28.75]
            lon: [31.25..158.75]
Number Of Attributes: 12
  _FillValue : 1e+20
  initial_time : 02/05/1981 (00:00)
  model : Climate Data Assimilation System (CDAS)
  parameter_number : 59
  parameter_table_version : 2
  gds_grid_type : 0
  level_indicator : 1
  units : kg/m^2/s
  long_name : Precipitation rate
  center : US National Weather Service - NCEP (WMC)
  average_op_ncl : dim_avg_n over dimension(s): time
  DataFreq : Monthly
(0) 0
(0) check_for_y_lat_coord: Warning: Data either does not contain a
valid latitude coordinate array or doesn't contain one at all.
(0) A valid latitude coordinate array should have a 'units' attribute
equal to one of the following values:
(0) 'degrees_north' 'degrees-north' 'degree_north' 'degrees north'
'degrees_N' 'Degrees_north' 'degree_N' 'degreeN' 'degreesN' 'deg north'
(0) check_for_lon_coord: Warning: Data either does not contain a valid
longitude coordinate array or doesn't contain one at all.
(0) A valid longitude coordinate array should have a 'units' attribute
equal to one of the following values:
(0) 'degrees_east' 'degrees-east' 'degree_east' 'degrees east'
'degrees_E' 'Degrees_east' 'degree_E' 'degreeE' 'degreesE' 'deg east'
(0) 1
yhuang@arc-env:/fs3/yhuang/nmm$

#####
load "$SysE/lib/ncl/helper_libs.ncl"

begin
  latS = -30.0
  latN = 30.0
  lonE = 30.0
  lonW = 160.0

  dir1 = "/fs3/SysE_DB/nmm/NMM/Monthly/Mean/"
  yrStrt = 1981
  yrLast = 2006
  year = ispan(yrStrt, yrLast,1) ; integer
  yrDir = year + "/" ; string
  varName= (/"precip"/)
  nyr = dimsizes(year)

  dir = str_concat(dir1+yrDir(0))
  fil = systemfunc("cd "+dir+" ; ls precip.nc") ;;;;;;;; read
precipitation
  f = addfile (dir+fil, "r")
  x = f->$varName(0)$
  dims= getfilevardims(f,varName(0))
  xs = x(:,{latS:latN},{lonE:lonW}) ; JJAS tropical Pacific
  xu = dim_avg_n_Wrap( xs,0)
  ds = dimsizes(xs)
  xx = new((/nyr,ds(0),ds(1),ds(2)/),float)
YYYYMM= new ( (/nyr,ds(0)/), double)
printVarSummary(xs)
printVarSummary(YYYYMM)

  delete (fil)
  do ny= 0,nyr-1
    dir = str_concat(dir1+yrDir(ny))
    fil = systemfunc("cd "+dir+" ; ls precip.nc")
    f = addfile (dir+fil, "r")

    x := f->$varName(0)$
    dims= getfilevardims(f,varName(0))
    xs := x(:,{latS:latN},{lonE:lonW}) ; Indian Ocean
    xx(ny,:,:,:)= xs
    YYYYMM(ny,:) = cd_calendar(xs&$xs!0$, 1)
  end do
printMinMax(xx,True)
print(YYYYMM(0:2,0:3))

  xx!0 = "year"
  xx!1 = "month"
  pcp = dim_avg_n_Wrap( xx,(/0,1/) ) *86400 ; kg/m^2/s -> mm/day
  copy_VarMeta(xu,pcp)
printMinMax(pcp,True)
printVarSummary(pcp)

  LON = fspan( 31.25,158.75, 52)
  LAT = fspan(-28.75, 28.75, 24)
  opt = True
  opt@critpc = 50 ; require only 50% of the values to be
precent
  pLo = area_hi2lores_Wrap (pcp&lon,pcp&lat, pcp , True, 1, LON, LAT,
False)
  pLo!0 = "lat"
  pLo!1 = "lon"
printVarSummary(pcp&lon)
printVarSummary(pcp&lat)
printVarSummary(LON)
printVarSummary(LAT)

  delete ([/fil,varName/])
  dir1= "/fs3/SysE_DB/nmm/NMM/Monthly/Mean/"
  dir = str_concat(dir1+yrDir(0))
  fil = systemfunc("cd "+dir+" ; ls *wnd_850.nc") ; input file name(s)
  f = addfile (dir+fil(0), "r")

  varName= (/"uwnd","vwnd"/)
  x := f->$varName(0)$
  dims = getfilevardims(f,varName(0))
  xs := x(:,{latS:latN},{lonE:lonW}) ; Indian Ocean
  ds = dimsizes(xs)
  xx := new((/nyr,ds(1),ds(2)/),float,"No_FillValue")

  delete (fil)
  do nf= 0,1
  do ny= 0,nyr-1
    dir = str_concat(dir1+yrDir(ny))
    fil = systemfunc("cd "+dir+" ; ls *wnd_850.nc") ; input file name(s)

    f = addfile (dir+fil(nf), "r")
    x = f->$varName(nf)$
    dims = getfilevardims(f,varName(nf))
    xs := x(:,{latS:latN},{lonE:lonW}) ; Indian Ocean
    xy = dim_avg_n_Wrap( xs, 0 )
    xx(ny,:,:)= xy
    xx!0 = "year"

    if ( ny .eq. nyr-1 .and. nf .eq. 0 ) then
      uwnd= dim_avg_n_Wrap( xx, 0 )
    else if ( ny .eq. nyr-1 .and. nf .eq. 1 ) then
      vwnd= dim_avg_n_Wrap( xx, 0 )
    end if
    end if
  end do
  end do
printVarSummary(uwnd)

  LON := fspan( 30.,160., 261)
  LAT := fspan(-30., 30., 121)
  opt = True
  opt@critpc = 50 ; require only 50% of the values to be
precent
  uLo = area_hi2lores_Wrap (uwnd&lon, uwnd&lat, uwnd, True, 1, LON, LAT,
False)
  vLo = area_hi2lores_Wrap (vwnd&lon, vwnd&lat, vwnd, True, 1, LON, LAT,
False)
printVarSummary(uwnd&lon)
printVarSummary(uLo)
printVarSummary(pLo)

  wks= gsn_open_wks("X11","pcpWind_nmm")
  gsn_define_colormap(wks,"BlueRed")

  pres= True
  opt= True
  myfill(pres,opt)
  pres@gsnAddCyclic = False
  pres@mpMinLatF = -30
  pres@mpMaxLatF = 30
  pres@mpMinLonF = 30
  pres@mpMaxLonF = 160

  pres@cnFillOn = True
  pres@gsnSpreadColors = True ; use full colormap
  pres@gsnSpreadColorStart = 10 ; for BlueRed
  pres@gsnSpreadColorEnd = 250 ; for BlueRed
  pres@cnLevelSelectionMode = "ManualLevels"
  pres@cnMinLevelValF = 1.
  pres@cnMaxLevelValF = 20.
  pres@cnLevelSpacingF = 1.

  pres@lbLabelBarOn = True
  pres@pmLabelBarWidthF= 0.8
  pres@lbLabelStride = 4
  pres@mpFillOn = False
  pres@mpOutlineBoundarySets = "National" ; turns on country
boundaries.
  pres@gsnRightString = "mm/day"
  pres@gsnLeftString = "NMM: Average Monthly Precipitation Rate during
JJAS"
  pres@cnFillDrawOrder = "Predraw"
  pres@gsnDraw = False
  pres@gsnFrame = False
  print("0")
  plot1= gsn_csm_contour_map(wks,pLo,pres)
  print("1")

  wres= True
  wres@vcRefMagnitudeF = 10.0 ; define vector ref mag
  wres@vcRefLengthF = 0.045 ; define length of vec
ref
  wres@vcMinDistanceF = 0.025 ; thin out windbarbs
  wres@vcVectorDrawOrder = "Predraw"
  wres@gsnLeftString = "NMM: Average Monthly Wind Vectors on
850 hPa during JJAS"
  wres@gsnLeftStringFontHeightF = 0.025
  wres@gsnRightStringFontHeightF = 0.025
  wres@gsnDraw = False
  wres@gsnFrame = False
  plot2= gsn_csm_vector(wks,uLo,vLo,wres)

  overlay(plot1,plot2)
  maximize_output(wks,True)
end

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Received on Mon Dec 9 00:38:06 2013

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