Re: constant output with function wrf_cape_2d

Dr. Pokhrel,

I forwarded this to wrfhelp to make sure there wasn't something
else I was missing.

One suggestion, which I already sent to you offline, is that you
need to make sure that the units of your data are correct and that
the arrays are all in the same order with respect to each other.

Please read the documentation at:

    http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_cape_2d.shtml

Make sure your pressure values coming in are hPa, as they will be
converted to Pa (multiplied by 0.01). I just realized the documentation
is misleading on this, as it states that the pressure values
can be Pa or hPa.

--Mary

On Tue, 16 Jun 2009, samirpokhrel wrote:

> Dear all,
>
> I am very new to NCL and I am trying to calculate cape from Japan reanalysis data
> (JRA25) using the ncl function wrf_cape_2d but I am getting a constant value. I am
> attaching both the data file (test2d.nc) and ncl script. May I know where I went wrong.
>
>
>
> The ncl script is :--------
>
> 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
>
> a = addfile("test2d.nc","r")
>
> P = a->PL
> T = a->TK
> Q = a->QG
> Z = a->GPH
> Z = Z/9.81
>
> Q = Q
>
> ZSFC = a->SPF3(:,0,:,:)
> ZSFC = ZSFC/9.81
> PSFC = a->PS(:,0,:,:)
> PSFC = PSFC/100
>
> cinfo = wrf_cape_2d( P, T, Q, Z, ZSFC, PSFC, False )
>
> cape = cinfo(0,:,:,:)
>
> copy_VarCoords(ZSFC, cape)
>
> filo = "cape2d.nc"
> system ("/bin/rm "+filo) ; remove any pre-existing file
> fo = addfile(filo , "c") ; open output file
> fo_at_title = "CAPE/CIN from JRA-25"
> cape_at_long_name = "Convective Available Potential Energy"
> cape_at_units = "j/kg"
>
> fo->cape = cape
>
> end
>
> Thanking in advance
>
> Dr. Samir Pokhrel
> Climate and Global Modelling Division
> Indian Institute of Tropical Meteorology
> Dr. Homi Bhabha Road Pashan Pune-411008
> Office - 020-25904307
> Mobile - 09881745234
>
>
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Received on Tue Jun 16 2009 - 14:15:49 MDT