Re: Stream function Problem with Pressure Levels

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Sun, 23 Nov 2008 14:10:24 -0700

The 1st script has

  lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
               20000., 10000., 5000., 3000., 1500., 750., 390., 200.,
              100., 50.,25., 14., 7., 3.5, 1.9, 0.95, 0.4, 0.1, 0.03 /)
  lev_p_at_units = "hPa"

========
The "zonal_psi" documentation states "The units must be in Pa."

Try changing to lev_p to PA in the 2nd script.

Helen Parish wrote:
> I am trying to plot the stream function for my dataset, but my pressure
> levels are not standard Earth based pressure levels. As a result I am
> getting the following error when I try to run my code. I suspect that
> the pressure levels must need to be adjusted in another routine, but I
> am not sure how and where to do this.
>
> This is the error I am getting:
>
> Number Of Attributes: 4
> units : m/s
> long_name : Meridional wind
> cell_method : time: mean
> _FillValue : -9999
> fatal:zonal_mpsi: The pressure array must be between the values of 500
> and 100500 (exclusive), and monotoni
> cally increasing
> fatal:Execute: Error occurred at or near line 5117 in file
> $NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed
> .ncl
>
> fatal:Execute: Error occurred at or near line 66 in file zonstream.ncl
>
>
> The code which generated this error (zonstream.ncl) is included below:
>
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> begin
> ; input file
> diri = "./"
> fili = "surf1925i.cam2.h0.0036-07-16-00000.nc"
> fi = addfile (diri+fili, "r")
> ; output file
> diro = "./"
> filo = "helen.nc"
> system ("/bin/rm -f "+diro+filo) ; remove any pre-exist file
> fo = addfile (diro+filo, "c")
> ; add any file attributes
> fo_at_title = fi_at_title + ": Selected Variables at pressure levels"
> fo_at_history = systemfunc ("date")
> fo_at_source = fi_at_source
> fo_at_case = fi_at_case
> fo_at_Conventions = fi_at_Conventions
>
> Var = (/ "T" , "Q", "U", "V"/) ; select variable to be
> interpolated.
> nVar = dimsizes (Var)
> ; desired output levels
> ;lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
> 20000., 10000., 5000., 3000., 1500.,
> 750., 390., 200., 100., 50.,25., 20., 15.,10., 8., 5.,3.,1. /)
> ;lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
> 20000., 10000., 5000., 3000., 1500.,
> 750., 390., 200., 100., 50.,25., 14., 7., 3.5, 1.9, 0.95, 0.4, 0.1, 0.01 /)
> lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
> 20000., 10000., 5000., 3000., 1500., 7
> 50., 390., 200., 100., 50.,25., 14., 7., 3.5, 1.9, 0.95, 0.4, 0.1, 0.03 /)
> ;lev_p = (/ 91500., 90000., 87500., 80000., 67500., 50000., 30000.,
> 20000., 10000., 5000., 3000., 1500.,
> 750., 390., 200., 100., 50.,25., 14., 7., 3.5, 2.0 /)
> lev_p!0 = "lev_p" ; variable and dimension name the
> same
> lev_p&lev_p = lev_p ; create coordinate variable
> lev_p_at_long_name = "pressure" ; attach some attributes
> lev_p_at_units = "hPa"
> lev_p_at_positive = "down"
>
> hyam = fi->hyam ; read hybrid info
> hybm = fi->hybm
> PS = fi->PS
> P0mb = 0.01*fi->P0
>
> do n=0,nVar-1 ; loop over the variables
> X = fi->$Var(n)$
> Xp = vinth2p (X, hyam, hybm, lev_p ,PS, 1, P0mb, 2, True)
> copy_VarAtts(X, Xp)
> fo->$Var(n)$ = Xp ; write to netCDF file
> print (Var(n)+": interpolated and written to netCDF")
> end do
>
> end
> ;***********************
> ; zonal.ncl
> ;***********************
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> ;***********************
> begin
> f = addfile ("helen.nc","r")
> print(f)
> v = f->V
> lat = f->lat
> printVarSummary( v )
>
> dimu = dimsizes( v )
> ntim = dimu(0)
> klvl = dimu(1)
> nlon = dimu(2)
> mlon = dimu(3)
>
> ; meridstream = zonal_mpsi_Wrap(v,lat,lev_p,PS)
> meridstream = zonal_mpsi_Wrap(v(:,::-1,:,:),lat,lev_p(::-1),PS)
>
> ;***********************
> ; Create Plot
> ;***********************
> wks = gsn_open_wks ("pdf", "surf1925i360716stream" ) ;
> open workstation
> gsn_define_colormap(wks,"rainbow") ; choose colormap
>
> res = True
> res_at_cnFillOn = True
> res_at_lbLabelAutoStride = True
> res_at_gsnMaximize = True ; if [ps, eps, pdf] make large
> res_at_gsnSpreadColors = True ; span color map
>
> do nt=0,ntim-1
>
> res_at_gsnCenterString = "surf1925i360716stream"
> ; plot = gsn_csm_pres_hgt(wks, u(nt,:,:,40), res ) ; (lev,lat)
> plot = gsn_csm_pres_hgt(wks, meridstream(nt,:,:), res ) ;
> (lev,lat)
> ; plot = gsn_csm_pres_hgt_streamline(wks, uavg(nt,:,:), res ) ;
> (lev,lat)
> ; plot = gsn_csm_contour (wks, uavg(t,:,:), res ) ; (lev,lat)
>
> res_at_trYReverse = True
> ; plot = gsn_csm_contour (wks, u(nt,:,:,0), res ) ; (lev,lat)
> ; plot = gsn_csm_contour (wks, u(nt,:,0,:), res ) ; (lev,lon)
>
> kl = 5
> res_at_mpFillOn = False
> res_at_mpGridAndLimbOn = True
> res_at_mpGridLineDashPattern = 2
> res_at_mpOutlineBoundarySets = "NoBoundaries"
> res_at_mpCenterLonF = 180.
> res_at_gsnCenterString = res_at_gsnCenterString+" p="+u&lev_p(kl)
> ; plot = gsn_csm_contour_map_ce (wks, u(nt,kl,:,:), res )
>
> end do
>
> end
>
>
> Thanks,
> Helen.
>
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Received on Sun Nov 23 2008 - 14:10:24 MST

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