CCSM conversion of Geoptential Height

Hi all,

I am using the vert_1.ncl to convert CCSM data (for WRF) from hybrid to
pressure.

Although, T, U, V and Humidity were successful, there is a problem with
conversion of geopotential heights, despite using surface geopotential
and surface pressure.

I use vinth2p_ecmwf, since I need values upto 1000mb .( ie
extrapolation).

My code is below

Any help in conversion please..

Thanks a lot

Sri

---------------------------

;*************************************************

; NCL tutorial script: vert_1.ncl

;************************************************

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"

;************************************************

begin

Ntime = 1

;************************************************

; file handling

;************************************************

   fn1 =
"b30.042e.cam2.h3.Z3.60E-150E_50S-50N.2000-01-01_cat_2000-12-31.nc" ;
define filename

   in1 = addfile(fn1,"r") ; open netcdf file

   Z3 = in1->Z3 ; select variable to
ave

   P0mb =1000.

   hyam = in1->hyam ; get a coefficiants

   hybm = in1->hybm ; get b coefficiants

   fn2 =
"b30.042e.cam2.h3.PS.60E-150E_50S-50N.2000-01-01_cat_2009-12-31.nc" ;
define filename

   in2 = addfile(fn2,"r") ; open netcdf file

   PS = in2->PS

   fn3 =
"b30.042e.cam2.h3.PHIS.60E-150E_50S-50N.2000-01-01_cat_2009-12-31.nc" ;
define filename

   in3 = addfile(fn3,"r") ; open netcdf file

   PHIS = in3->PHIS

   fn4 =
"b30.042e.cam2.h3.TS.60E-150E_50S-50N.2000-01-01_cat_2009-12-31.nc" ;
define filename

   in4 = addfile(fn4,"r") ; open netcdf file

   TS = in4->TS

;************************************************

; define other arguments required by vinth2p

;************************************************

; type of interpolation: 1 = linear, 2 = log, 3 = loglog

   interp = 2

; is extrapolation desired if data is outside the range of PS

   extrap = True

; create an array of desired pressure levels:

pnew =
(/1000,950,900,850,800,750,700,650,600,550,500,450,400,350,300,250,200,1
50,100/)

;************************************************

; calculate T on pressure levels

;************************************************

; note, the 7th argument is not used, and so is set to 1.

;************************************************

; VARonP =
vinth2p(Z3(0:Ntime,:,:,:),hyam,hybm,pnew,PS(0:Ntime,:,:),interp,P0mb,1,e
xtrap)

   VARonP =
vinth2p_ecmwf(Z3(0:Ntime,:,:,:),hyam,hybm,pnew,PS(0:Ntime,:,:),interp,P0
mb,1,extrap,-1,TS(0:Ntime,:,:),PHIS(0:Ntime,:,:))

;output in nc file

  system("/bin/rm -f ./Z3_pressure.nc") ; remove any pre-existing
file

  ncdf = addfile("./Z3_pressure.nc" ,"c") ; open output netCDF file

  filedimdef(ncdf,"time",-1,True)

  VARonP!0 = "time" ; assign named dimensions

  VARonP!1 = "lev"

  VARonP!2 = "lat"

  VARonP!3 = "lon"

  VARonP&time = in1&time(0:Ntime)

  VARonP&lev = pnew

  VARonP&lat = in1&lat

  VARonP&lon = in1&lon

  VARonP@long_name = "Geopotential Height on plevel" ; assign
name

  VARonP@units = "m"

  ncdf->Z3_pres = VARonP

  print("finish convert Z3 to pressure level")

  print("output .nc: ./Z3_pressure.nc")

end

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Tue Feb 2 02:27:59 2010