[ncl-talk] calculate a variable from other wrf variables and plot it
Mary Haley
haley at ucar.edu
Wed Jun 1 08:40:14 MDT 2016
Enric,
If you are getting a message saying that "thetae" is undefined, then that
means you are trying to reference thetae before it's been initialized.
I see that you have a calc_thetae function, but you never called it before
you referenced "thetae":
thetae = calc_thetae(.....)
contour_t2 = wrf_contour(a,wks,thetae,opts)
--Mary
On Sun, May 29, 2016 at 12:05 AM, Agud Pique, Enric <eagud.q at ccma.cat>
wrote:
> Hello,
>
> I have used a different variable name, "hum", now I receive the following
> message...
>
> Copyright (C) 1995-2015 - All Rights Reserved
> University Corporation for Atmospheric Research
> NCAR Command Language Version 6.3.0
> The use of this software is governed by a License Agreement.
> See http://www.ncl.ucar.edu/ for more details.
> fatal:Variable (thetae) is undefined
> fatal:["Execute.c":8575]:Execute: Error occurred at or near line 60 in
> file plot2.ncl
>
>
> In line 60 there is contour_t2 = wrf_contour(a,wks,thetae,opts)
>
> Thank you
>
> Enric
> ------------------------------
> *De:* Evelyn Grell - NOAA Affiliate [evelyn.grell at noaa.gov]
> *Enviat el:* dissabte, 28 / maig / 2016 18:06
> *Per a:* Agud Pique, Enric
> *A/c:* Mary Haley; ncl-talk at ucar.edu
>
> *Tema:* Re: [ncl-talk] calculate a variable from other wrf variables and
> plot it
>
> Enric,
>
> "relhum" is already defined as an NCL function, so try using a different
> variable name.
>
> http://www.ncl.ucar.edu/Document/Functions/Built-in/relhum.shtml
>
> Good luck,
> Evelyn
>
>
> On Sat, May 28, 2016 at 1:26 AM, Agud Pique, Enric <eagud.q at ccma.cat>
> wrote:
>
>> Hello Mary,
>>
>> I get this error
>>
>> [Enric at meteo em_real]$ ncl plot2.ncl
>> Copyright (C) 1995-2015 - All Rights Reserved
>> University Corporation for Atmospheric Research
>> NCAR Command Language Version 6.3.0
>> The use of this software is governed by a License Agreement.
>> See http://www.ncl.ucar.edu/ for more details.
>> fatal:syntax error: line 15 in file plot2.ncl before or near =
>> relhum =
>> -------^
>>
>> fatal:error in statement
>> fatal:Syntax Error in block, block not executed
>> fatal:error at line 66 in file plot2.ncl
>>
>> Best, thank you
>> ------------------------------
>> *De:* Agud Pique, Enric
>> *Enviat el:* dissabte, 28 / maig / 2016 09:25
>> *Per a:* Mary Haley
>> *A/c:* ncl-talk at ucar.edu
>> *Tema:* RE: [ncl-talk] calculate a variable from other wrf variables and
>> plot it
>>
>> Hello Mary,
>>
>> I get this error
>>
>> [Enric at meteo em_real]$ ncl plot2.ncl
>> Copyright (C) 1995-2015 - All Rights Reserved
>> University Corporation for Atmospheric Research
>> NCAR Command Language Version 6.3.0
>> The use of this software is governed by a License Agreement.
>> See http://www.ncl.ucar.edu/ for more details.
>> fatal:syntax error: line 15 in file plot2.ncl before or near =
>> relhum =
>> -------^
>>
>> fatal:error in statement
>> fatal:Syntax Error in block, block not executed
>> fatal:error at line 66 in file plot2.ncl
>>
>> ------------------------------
>> *De:* Mary Haley [haley at ucar.edu]
>> *Enviat el:* dissabte, 28 / maig / 2016 00:03
>> *Per a:* Agud Pique, Enric
>> *A/c:* ncl-talk at ucar.edu
>> *Tema:* Re: [ncl-talk] calculate a variable from other wrf variables and
>> plot it
>>
>> Does running the script produce an error message? If so, please email the
>> exact error message.
>>
>> I do see that you are imbedding a function inside the main code. I
>> believe this is acceptable in NCL, but just to be sure, I need to see what
>> your error message states.
>>
>> If there's no error message, then describe in more detail what the
>> problem is (i.e. if the plot is bad, describe how it is bad, and include an
>> image if possible).
>>
>> Thanks,
>>
>> --Mary
>>
>>
>> On Fri, May 27, 2016 at 1:33 PM, Agud Pique, Enric <eagud.q at ccma.cat>
>> wrote:
>>
>>> Hello people,
>>>
>>>
>>>
>>> I would like to plot a variable calculated from several wrf
>>> variables....for example, the following code....get temperature, pressure
>>> and relative humidity and after I select tempC and relhum in 850 hPa...
>>> after calculate Theta E, I want to plot it, but when I execute the scripts
>>> it fails...what is wrong?
>>>
>>>
>>>
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/wrf/WRFUserARW.ncl"
>>> begin
>>> a = addfile("./wrfout_d01_2016-05-24_18:00:00","r")
>>> wks = gsn_open_wks("X11","plt_Surface")
>>>
>>>
>>> tc = wrf_user_getvar(a,"tc",0)
>>> p = wrf_user_getvar(a,"pressure",0)
>>> rh = wrf_user_getvar(a,"rh",0)
>>> pressure = 850.
>>> res = True
>>>
>>> tempC = wrf_user_intrp3d(tc,p,"h",850.,0.,res)
>>> relhum= wrf_user_intrp3d(rh,p,"h",850.,0.,res)
>>>
>>> pltres = True
>>> mpres = True
>>>
>>> opts = res
>>> opts at cnFillOn = True
>>> opts at cnLevelSelectionMode = "ExplicitLevels"
>>>
>>> ;-----------------------------------------
>>> ; Calculate Theta E
>>> ;-----------------------------------------
>>>
>>>
>>> undef("calc_thetae")
>>>
>>> function calc_thetae(tempC,pres,relhum)
>>>
>>> local tempC, pres, relhum, tc, tk, pp, p0, rh, es, en, rv, rd, cp, kd,
>>> td, tl, thetal, thetae
>>>
>>> begin
>>> pres = 850.
>>> Tc = tempC ; [C]
>>> tk = tempC+273.15 ; [K]
>>> pp = pres ; [hPa]
>>> p0 = 1000 ; [hPa]
>>> rh = relhum/100 ; [no dimensions]
>>> es = 6.112*exp(17.67*Tc/(Tc+243.5)) ; [hPa]
>>> en = rh*es ; [hPa]
>>> rv = 0.622*en/(pp-en) ; [no dimensions]
>>> rd = 287.04 ; [J/kgK]
>>> cp = 1005.7 ; [J/kgK]
>>> kd = rd/cp ; [no dimensions]
>>> tl = (1/((1/(tk-55))-(log(rh)/2840)))+55 ; [K]
>>> thetal = tk*((p0/(pp-en))^kd)*((tk/tl)^(0.28*rv)) ; [K]
>>> thetae = thetal*exp(((3036/tl)-1.78)*rv*(1+0.448*rv)) ; [K]
>>> thetae = thetae-273.15 ; [C]
>>> return(thetae)
>>> end
>>>
>>> contour_t2 = wrf_contour(a,wks,thetae,opts)
>>>
>>> plot= wrf_map_overlays(a,wks,(/contour_t2/),pltres ,mpres)
>>>
>>> end
>>>
>>> Best
>>>
>>>
>>>
>>> Enric
>>>
>>> *De:* Agud Pique, Enric
>>> *Enviat:* dimarts, 24 / maig / 2016 21:17
>>> *Per a:* ncl-talk at ucar.edu
>>> *Tema:* get some variables from wrf output
>>>
>>>
>>>
>>> Hello people,
>>>
>>>
>>>
>>> I would like to use wrf_user_getvar or another function in order to get
>>> from a wrf filet he following variables:
>>>
>>>
>>>
>>> *Temperature on 850 hPa-Level in ºC,*
>>>
>>> *Geopotential height on 850 hPa-Level *
>>>
>>> *Relative humidity on 850 hPa-Level *
>>>
>>>
>>>
>>> I know how to get the temperature on T2
>>>
>>> T2 = wrf_user_getvar(a,"T2",0)
>>> where a is the wrf file...but in 850hPa?
>>>
>>>
>>>
>>> Thank you
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
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>>>
>>>
>>
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>
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