Dear Wei
Your code is not exactly like the one on the example.
TK = wrf_tk (P, theta)
RH = wrf_rh (qv, P, TK)
You are missing the first of these lines.
Perhaps, Tk does not have the right units?
Good luck,
Andrea
-- Andrea N. Hahmann Senior Scientist Wind Energy Division Risø DTU Technical University of Denmark Risø National Laboratory for Sustainable Energy Frederikborgvej 399, P.O. Box 49 4000 Roskilde, Denmark Direct +45 4677 5471 Mobil: +45 2133 0550 ahah@risoe.dtu.dk www.risoe.dtu.dk From: wei huang <whua27@gmail.com> Date: Tue, 01 Feb 2011 00:07:23 +0800 To: <ncl-talk@ucar.edu> Subject: Re: fatal:Div: operator failed, can't continue Thanks for your cooperation, kindly, I have changed the pressure hPa to Pa but still it does not working and giving the same error: Any help will be appreciated. thanks P = a->P ; perturbation; Pa Pb = a->PB ; base state pressure; Pa P = P + Pb ; total pressure T = a->T ; perturbation potential temperature tk = T + 300. qv = a->QVAPOR ; water vapor mixing ratio(kg/kg) RH = wrf_rh (qv, P, tk) printVarSummary(RH) qs = (qv/RH)*100 printVarSummary(qs) Error: fatal:divide: Division by 0, Can't continue fatal:Div: operator failed, can't continue fatal:Execute: Error occurred at or near line 17 in file On Mon, Jan 31, 2011 at 11:36 PM, Dennis Shea <shea@ucar.edu> wrote: > Please read the documentation: > http://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_rh.shtml > > == > "qv" must be kg/kg , you are passing "g/kg" > "P" must be "Pa", you are passing "hPa" > > > > On 1/31/11 7:09 AM, wei huang wrote: >> Dear NCL users, >> >> I got an error to calculating saturated mixing ratio from the wrf water >> vapor mixing ratio. I don¹t know my assumption is correct or not. Could >> anyone help me to figure out the problem or any advice about it? >> >> Thanks >> >> wei >> a = addfile("wrfout_02.nc <http://wrfout_02.nc/> <http://wrfout_02.nc >> <http://wrfout_02.nc/> >","r") >> >> >> P= a->P; perturbation >> >> Pb = a->PB; base state pressure >> >> P= P + Pb; total pressure >> >> T = a->T; perturbation potential temperature >> >> tk = T + 300. >> >> qv = a->QVAPOR/1000; water vapor mixing ratio(g/kg) >> >> RH = wrf_rh (qv, P*.01, tk) ;P*0.01 converts Pa to hPa >> >> printVarSummary(RH) >> >> qvs = (qv/RH)*100; saturated water vapor mixing ratio(g/kg) >> >> printVarSummary(qvs) >> >> end >> >> ;***************************************** >> >> Variable: RH >> >> Type: float >> >> Total Size: 102667500 bytes >> >> 25666875 values >> >> Number of Dimensions: 4 >> >> Dimensions and sizes:[24] x [39] x [south_north | 160] x [west_east | 105] >> >> Coordinates: >> >> Number Of Attributes: 2 >> >> units :% >> >> description : Relative Humidity >> >> fatal:divide: Division by 0, Can't continue >> >> fatal:Div: operator failed, can't continue >> >> fatal:Execute: Error occurred at or near line 16 in file >> >> >> >> _______________________________________________ >> 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
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Received on Mon Jan 31 09:26:56 2011
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