回复： interpolate WRF output to isentropic levels

Dear Dennis,


I am trying to interpolate the vertical velocity output from WRF to a specified isentropic level (e.g., 307 K surface),


but I got a warning message:


"fatal:Dimension (bottom_top) of (xlvl) does not have an associated coordinate variable"



Here is my code:


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


begin
;
; The WRF ARW input file.
; This needs to have a ".nc" appended, so just do it.
  a = addfile("./wrfout_d03_2011-06-13_18_00_00.nc","r")


; We generate plots, but what kind do we prefer?
; type = "x11"
; type = "pdf"
 type = "eps"
; type = "ncgm"
  wks = gsn_open_wks(type,"isent")
  ;gsn_define_colormap(wks,"isent") ; Overwrite the standard color map
  
; Set some basic resources
  res = True
  res@MainTitle = "REAL-TIME WRF"


  res@mpDataBaseVersion = "HighRes"
  res@mpDataSetName = "Earth..4"
  res@mpGridAndLimbOn = False ; Turn off lat/lon lines
  res@mpOutlineOn = True ; Turn on map outlines
  ;res@mpGeophysicalLineColor = "Black" ; Change the outline line color
  res@mpGeophysicalLineThicknessF= 2. ; double the thickness of geophysical boundaries
  res@mpOutlineSpecifiers = (/"China","Taiwan","Disputed area between India and China","India:Arunachal Pradesh"/)


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


; Which times and how many time steps are in the data set?
  times = wrf_user_getvar(a,"times",-1) ; get all times in the file
  ntimes = dimsizes(times) ; number of times in the file
  
  
;Zoom
  lats = (/ 27.7, 29.7 /)
  lons = (/ 115.5, 119.5 /)
  loc = wrf_user_ll_to_ij(a, lons, lats, True)
 
; loc(0,;) is west-east (x) ; loc(1,:) is south-north (y)
; subtract one since we want to use it as an index in NCL
  x_start = loc(0,0) - 1
  x_end = loc(0,1) - 1
  y_start = loc(1,0) - 1
  y_end = loc(1,1) - 1


res@mpMinLatF = lats(0)
res@mpMaxLatF = lats(1)
res@mpMinLonF = lons(0)
res@mpMaxLonF = lons(1)
  
  
     ;do it = 25,ntimes-1 ; TIME LOOP
         do it = 22, 25
 
     print("Working on time: " + times(it) )
     res@TimeLabel = times(it) ; Set Valid time to use on plots


; First get the variables we will need
    
         theta= wrf_user_getvar(a,"theta",it)
    


     x = wrf_user_getvar(a,"wa",it)
        
         
         
         lvl = (/ 307. /)
         lvl@description = "isentropic level"
         lvl@units = theta@units
     lvl!0 = "lvl"
     lvl&lvl = lvl
         
         
         xlvl = int2p_n_Wrap (theta, x, lvl, 0, 1)
        
         xlvl@lat2d = a->XLAT(0,:,:) ; direct assignment
     xlvl@lon2d = a->XLONG(0,:,:)
         printVarSummary(xlvl)
     printMinMax(xlvl, 0)
        
                              
     res@cnFillOn = True ;automatically creates a color bar.
     res@ContourParameters = (/ 0.1, 1.3, 0.3/) ; (/ start, end, step /)


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
         
        plot = gsn_csm_contour_map(wks,xlvl({lvl(0)},y_start:y_end,x_start:x_end),res)
 


   end do ; END OF TIME LOOP


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end‍

‍







------------------ 原始邮件 ------------------
发件人: "Dennis Shea";<shea@ucar.edu>;
发送时间: 2014年7月7日(星期一) 晚上10:00
收件人: "Li Qi"<liqi123sh@qq.com>;
抄送: "ncl-talk"<ncl-talk@ucar.edu>; "wrfhelp"<wrfhelp@ucar.edu>;
主题: Re: [ncl-talk] interpolate WRF output to isentropic levels



It is the exact same approach as outlined at
      http://www.ncl.ucar.edu/Applications/isent.shtml,%e2%80%8d

Even easier because wrf_user_getvar returns theta.

load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"

  a = addfile("...","r")
  time = -1
  theta= wrf_user_getvar(a,"theta",time)
   printVarSummary(theta)

  x = wrf_user_getvar(a,"tc" ,time)
  printVarSummary(x)
  printMinMax(x, 0)

                                                         ; isentropic level(s)
 
  lvl = 320. ; (/300., 320., 340./)
  lvl@description = "isentropic level"
  lvl@units = theta@units

  xlvl = int2p_n_Wrap (theta, x, lvl, 0, 1)
   printVarSummary(xlvl)
  print("xlvl: min="+min(xlvl)+" max="+max(xlvl))
-----

Please send WRF related questions to wrfhelp@ucar.edu

 You can cc ncl-talk@ucar.edu







On Sun, Jul 6, 2014 at 8:35 PM, Li Qi <liqi123sh@qq.com> wrote:
 Dear all,

I'd like to interpolate a variable in WRF output to a specified isentropic level.
 

GrADS has a function (i.e., isen(field,tgrid,pgrid,tlev)‍) to complete the task, like
* 1) Display vertical velocity field on 320K surface:
 *
* "d "isen(w,t,PP,320)‍



Is there any corresponding function in NCL?


I've checked the examples and got this one: http://www.ncl.ucar.edu/Applications/isent.shtml,%e2%80%8d
 

but I have no idea about the hybrid coef in WRF.


Best,


Li Qi

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Received on Wed Jul 09 08:01:22 2014