Re: Interpolation of WRF data from pressure levels to height levels

WRF related questions should be sent to wrfhelp@ucar.edu

cc'd here.

On 11/27/2012 09:14 AM, Kv Gopalkrishnan wrote:
> Hi
> I am trying to interpolate u,v,w velocity components to some
> specific height levels (this is an array like new_ht =
> (/10.0,20.0,30.,40.,50.,60.,70.,80.,90.,100.,110./) ). Now if I am
> using the data at mass points (for instance get ua,uv,uw) then
> everything goes smoothly since they r unstaggered grid points. However,
> I need to keep the velocity u,v,w in the nodes as the original data (in
> short i want the data staggered). This is mainly because i use a
> advection code that makes use of the staggered velocity components. I
> tried to write an ncl code for this but i manage to get errors while
> doing so. The code is as follows:
>
>
> 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/wrf/WRFUserARW.ncl"
>
>
> begin
> a = addfile("wrfout_d02_2010-07-11_00:00:00.nc <http://00.nc>","r")
>
>
>
> ; getting wind components
>
> u = wrf_user_getvar(a,"U",-1)
> dim_u = dimsizes(u)
> print(dim_u)
>
> v = wrf_user_getvar(a,"V",-1)
> dim_v = dimsizes(v)
> print(dim_v)
>
> w = wrf_user_getvar(a,"W",-1)
> dim_w = dimsizes(w)
> print(dim_w)
>
> ; creating new varaibles
> va = new((/dim_v(0),dim_v(1),dim_v(2),dim_v(3)/),float)
> dim_va = dimsizes(va)
> print(dim_va)
>
>
> ua = new((/dim_u(0),dim_u(1),dim_u(2),dim_u(3)/),float)
> dim_ua = dimsizes(ua)
> print(dim_ua)
>
>
> wa = new((/dim_w(0),dim_w(1),dim_w(2),dim_w(3)/),float)
>
>
>
> ; new height levels to be interpolated
> new_ht = (/10.0,20.0,30.,40.,50.,60.,70.,80.,90.,100.,110./) ; new
> height levels to be interpoalted
> dim_new_ht = dimsizes(new_ht) ; size of the
> height levels
>
> ;getting height levels and terrian height levels from the file
>
> z = wrf_user_getvar(a, "z",-1) ; grid point height
> dimz = dimsizes(z) ; get the
> dimensions
> ter = wrf_user_getvar(a,"ter",-1) ; get terrian
> height
> dimter = dimsizes(ter) ; get the
> dimensions
>
>
> ;*************************************************
> ;Print dimensions of height and terrian height to
> ;the screen
> ;*************************************************
> print(dimz)
> print(dimter)
> ;*************************************************
> nheight = conform(z,ter,(/0,2,3/)) ; the 0,2,3 of termatches that of z
> and then is expanded
> nheight_size = dimsizes(nheight) ; Defines the height of the nheight
> print(nheight_size) ; prints out in the screen
>
> height = z-nheight ; subracting the height from the
> terrian height
> dim_height = dimsizes(height) ; getting the dimsizes
> print(dim_height) ; printing the dimsizes to the screen
> ;*************************************************
>
> ; print(dimsizes(ua))
> ; print(dimsizes(u))
>
> va = wrf_user_intrp3d( v,height,"h", 10.,0.0,False) ; interpolating
> the values in diff height levels
> print(dimsizes(va))
> print(dimsizes(v))
>
>
>
> ;do it = 0,dim_new_ht-1 ; do loop for the array of new_ht
> levels
> ;getting height levels and terrian height levels from the file
>
> z = wrf_user_getvar(a, "z",-1) ; grid point height
> dimz = dimsizes(z) ; get the
> dimensions
> ter = wrf_user_getvar(a,"ter",-1) ; get terrian
> height
> dimter = dimsizes(ter) ; get the
> dimensions
>
>
> ;*************************************************
> ;Print dimensions of height and terrian height to
> ;the screen
> ;*************************************************
> print(dimz)
> print(dimter)
> ;*************************************************
> nheight = conform(z,ter,(/0,2,3/)) ; the 0,2,3 of termatches that of z
> and then is expanded
> nheight_size = dimsizes(nheight) ; Defines the height of the nheight
> print(nheight_size) ; prints out in the screen
>
> height = z-nheight ; subracting the height from the
> terrian height
> dim_height = dimsizes(height) ; getting the dimsizes
> print(dim_height) ; printing the dimsizes to the screen
> ;*************************************************
>
> ; print(dimsizes(ua))
> ; print(dimsizes(u))
>
>
> do it = 0,dim_new_ht-1 ; do loop for the array of new_ht
> levels
> ; do dim3 = 0,dim_u(3)-1
> ua(:,it,:,:) = wrf_user_intrp3d( u,height,"h",
> new_ht(it),0.0,False) ; interpolating the values in diff height levels
> ; end do
> end do
> dim_ua = dimsizes(ua)
> print(dim_ua)
>
> end
>
>
>
>
> This does not work probably because the dimensions are not equal.
>
> More precisely (may be) because
> The size of 'height' is
>
>
> Variable: dim_height
> Type: integer
> Total Size: 16 bytes
> 4 values
> Number of Dimensions: 1
> Dimensions and sizes: [4]
> Coordinates:
> (0) 4
> (1) 62
> (2) 220
> (3) 200
>
> and that of u and uv is
> Variable: dim_u
> Type: integer
> Total Size: 16 bytes
> 4 values
> Number of Dimensions: 1
> Dimensions and sizes: [4]
> Coordinates:
> (0) 4
> (1) 62
> (2) 220
> (3) 201
>
> The dimension(3) in the case of u component gives the main problem.
>
> So how do i solve this problem? The error that i get is as follows:
>
> fatal:Dimension size mismatch, dimension (3) of left hand side reference
> does not have the same size as the right hand side reference after
> subscripting.
>
> Any help greatly appreciated.
>
> Kind Regards
> KV
>
>
>
>
>
>
>
>
> --
> K.V.
>
>
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>

_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Tue Nov 27 09:19:37 2012