Spectral Magnitude Contour as function of period and altitude ?

Does anyone know how to generate a contour of the magnitude of the
spectra of a time series of netcdf files, plotted as a function of
period and altitude/pressure level, at a give latitude ?.

I would also like to plot a contour of the spectral magnitude as a
function of period and latitude, at a given altitude.

I have produced spectra for the time series at a fixed latitude and
fixed altitude, using specx_anal, but I am not sure if I can use the
same routine to produce a magnitude contour as a function of period
and altitude, and I could not find any examples where this was done.

Does anyone know how to do this ?.

I enclose my current script for specx_anal below.

Thanks,
Helen.

;***********************
; fourtest.ncl
;***********************
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"

begin

; Keep all files open when have a lot of files :
   setfileoption("nc","SuppressClose",False)

   diri = "./"
   fili = systemfunc("cd "+diri+" ; ls zeusrand09125*.cam2.h0*nc")

   f = addfiles (fili,"r")
   U = addfiles_GetVar(f,fili,"U")
   lat = addfiles_GetVar(f,fili,"lat")
   lon = addfiles_GetVar(f,fili,"lon")
   lev = addfiles_GetVar(f,fili,"lev")
   printVarSummary( U )

   dimu = dimsizes( U )
   ntim = dimu(0)
   klvl = dimu(1)
   nlon = dimu(2)
   mlon = dimu(3)

  uavg = dim_avg_Wrap(U)

;***********************
; Create Plot
;***********************
   d = 1
   sm = 3
   pct = 0.1

    kl = 49 ; 0 km altitude
    nl = 27 ; 65 deg latitude
    ml = 144
    nt = 0
   spec = specx_anal(U(lev|kl, lat|nl, lon|ml, time|:),d,sm,pct)

   wks = gsn_open_wks ("eps", "spectrum.0km.65lat" ) ;
open workstation
   gsn_define_colormap(wks,"rainbow") ; choose colormap

   res = True
      res@gsnCenterString = "Zonal wind spectrum, 0 km altitude,
65~S~0~N~ latitude"
      res@tiXAxisString = "Period (Earth years)"
     res@tiYAxisString = "Variance (m~S~2~N~ s~S~-2~N~)"

    plot = gsn_csm_xy(wks,1/spec@frq,spec@spcx,res)

end

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Received on Sat Nov 6 01:15:40 2010