[ncl-talk] RUC2-Analysis Data Incorrectly Interpolated to Surface

[Dennis Shea]

You had print statements in the code. You should have looked at the output.

p  = f->lv_ISBL3                                 ; hPa
print(p)
t

You had

[snip]
     p = int2flt(f->lv_ISBL3)             ; <=== hPa
    psfc = f->PRES_252_SFC        ; "ground" pressure => pressure  (Pa)
        ; change units and calculate needed variables
    psfc = psfc/100
    psfc at units = "hPa"

    p = p/100                                   ; NO!  why
    p at units = "hPa"                       ; p was in hPa
[snip]

Note: there is no need for:
    p = int2flt(f->lv_ISBL3)
the following is fine
    p = f->lv_ISBL3

See attachment


On Fri, Jan 29, 2016 at 3:12 PM, Michelle Serino <mmserino at tamu.edu> wrote:

> Hi Dennis,
>
> Thank you for getting back to me; your advice helped!  I am now trying to
> adapt your advice to a separate script I have for the 25-km RUC2-Analysis,
> and I receive the error:
>
> fatal:Le: Number of dimensions do not match, can't continue
>
> fatal:["Execute.c":8575]:Execute: Error occurred at or near line 97 in
> file sounding25.ncl
>
>
> I did my best to make sure that I converted the variable names to those of
> the 25-km format and that I didn't make any other simple mistakes.  I could
> easily have overlooked something, though.  Again, my script is attached,
> and the direct link to the 25-km data is below. Thank you for your
> continued help!
>
>
>
> https://www.dropbox.com/s/fhq2s4o8vp0yiol/ruc2anl_252_20090605_1200_000.grb?dl=0
>
>
> Best regards,
>
>
> Michelle Serino
>
> Michelle Serino
> M.S. Candidate
> Texas A&M University
> Atmospheric Sciences Dept.
> Eller O&M, Suite 1017
> College Station, TX 77843
> (484) 769-0949
>
> On Thu, Jan 28, 2016 at 8:45 PM, Dennis Shea <shea at ucar.edu> wrote:
>
>> A key is  the 'level_type' attribute associated with the pressure
>> variables (PRES_). There are numerous PRES_ variables. In particular,
>>
>>       float PRES_P0_L1_GLC0 ( ygrid_0, xgrid_0 )
>>          center :       US National Weather Service - NCEP (WMC)
>>          production_status :    Operational products
>>          long_name :    Pressure
>>          units :        Pa
>>          _FillValue :   1e+20
>>          coordinates :  gridlat_0 gridlon_0
>>          grid_type :    Lambert Conformal can be secant or tangent,
>> conical or bipolar
>>          parameter_discipline_and_category :    Meteorological products,
>> Mass
>>          parameter_template_discipline_category_number :        ( 0, 0,
>> 3, 0 )
>>          level_type :   Ground or water surface
>> <*******************************************
>>          level :         0
>>          forecast_time :        0
>>          forecast_time_units :  hours
>>          initial_time : 06/05/2009 (12:00)
>>
>> It is a guess that this is the surface pressure (psfc). All pressure
>> levels > psfc must be extrapolated. [ *Extrapolation is always dangerous!]
>>
>> The 'ind' function can be used to get all 'valid' levels [ p<psfc ]. Try
>> attached.
>>
>> Cheers
>>
>>
>> On Thu, Jan 28, 2016 at 11:47 AM, Michelle Serino <mmserino at tamu.edu>
>> wrote:
>>
>>> Good afternoon,
>>>
>>> I am plotting RUC2-Analysis data on a skew-T.  Because this is analysis
>>> data, it seems that the data are always interpolated to the 1000-mb
>>> surface, regardless of the chosen location.  For example, in a high
>>> elevation location like Denver, the data extend down to 1000 mb, which is
>>> unrealistic.  This creates incorrect surface values, which results in a
>>> very incorrect value of surface CAPE.
>>>
>>> I am wondering if, while still plotting on a skew-T, there is a way to
>>> specify the data that is plotted.  Or, if there is another, more realistic,
>>> way around this.  With a real sounding, I would not have this problem, so I
>>> am sure there is a way to fix this for the analysis data.  I have attached
>>> the script I am using, along with its plot and an observed sounding for the
>>> same location (Denver).  The direct link to the analysis data I am using is
>>> provided below.  I appreciate any help!
>>>
>>>
>>> https://www.dropbox.com/s/qpe96hmhh9hsi0h/ruc2anl_130_20090605_1200_000.grb2?dl=0
>>>
>>> Best regards,
>>>
>>> Michelle Serino
>>>
>>> Michelle Serino
>>> M.S. Candidate
>>> Texas A&M University
>>> Atmospheric Sciences Dept.
>>> Eller O&M, Suite 1017
>>> College Station, TX 77843
>>> (484) 769-0949
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>>
>>
>
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