Re: Trying to calculate vertical wind shear

From: <sbasu_at_nyahnyahspammersnyahnyah>
Date: Wed Nov 17 2010 - 12:05:34 MST

I am using a small portion of data now and I got du/dz and dt/dz. Using
those I went on to calculate Eady Growth Rate.
But now when I am trying to plot Eady Growth Rate it cannot plot and its
not giving any error or anything.I waited for 1hr for the program to end
but it didn't end.
But if I keep the calculation of Eady Growth Rate and plot du/dz or dt/dz
it is plotting it fine. So there is possibly nothing wrong with the Eady
Growth Rate calculation and its also printing out printVarSummary for it.
I am attaching the script.

Thanks,
Soumik

Dennis Shea wrote:
>
> This is because NCL versions through 5.2.1 [current release]
> do not all variables > 2GB. Your variable is
> 965*26*128*256*4 [*4 because each float is 4 bytes].
>
> The next release of NCL [ 6.0.0 ] will allow
> variables > 2GB.
>
> Right now, break the data into smaller parts.
>
> Good luck
>
> On 11/16/2010 12:08 PM, sbasu@iarc.uaf.edu wrote:
>> But it is giving me a segmentation fault after printVarSummary(pm). At
>> this point of the script:
>> Variable: pm
>> Type: float
>> Total Size: -1006370816 bytes
>> 822149120 values
>> Number of Dimensions: 4
>> Dimensions and sizes: [time | 965] x [lev | 26] x [lat | 128] x [lon |
>> 256]
>> Coordinates:
>> time: [ 0.. 241]
>> lev: [3.54463800000001..992.5560999999998]
>> lat: [-88.92773535229591..88.92773535229591]
>> lon: [ 0..358.59375]
>> Number Of Attributes: 2
>> units : Pa
>> long_name : pressure
>> (0)
>> Segmentation fault
>>
>> Thanks,
>> Soumik
>>
>>
>>
>> Dennis Shea wrote:
>>> The pres_hybrid_ccm function calculates the pressures at every grid
>>> point and level. This is need to calculate the vertical gradients
>>> dt/dp and du/dp.
>>>
>>> There was an attachment ... please look at it.
>>>
>>> ===
>>> If you want dt/dz and du/dz, then
>>>
>>> z = f->Z3(tStrt:tLast,:,:,:)
>>>
>>> and replace
>>>
>>> dtdp = center_finite_diff_n (pt,pm,False,0, 1)
>>> dudp = center_finite_diff_n (u,pm,False,0, 1)
>>>
>>> with
>>>
>>> dtdz = center_finite_diff_n (pt,z,False,0, 1)
>>> dudz = center_finite_diff_n (u,z,False,0, 1)
>>>
>>>
>>> On 11/16/2010 11:04 AM, sbasu@iarc.uaf.edu wrote:
>>>> Thanks for the reply. But I could not understand how to get the
>>>> vertical
>>>> gradient du/dz or d(pt)/dz with that function?
>>>>
>>>> Thanks,
>>>> Soumik
>>>>
>>>> Dennis Shea wrote:
>>>>> The function to use is
>>>>>
>>>>> https://www.ncl.ucar.edu/Document/Functions/Built-in/pres_hybrid_ccm.shtml
>>>>>
>>>>> This calculates the pressure at every grid point level.
>>>>> It can be placed in your 'pt' calculation.
>>>>>
>>>>> *** Please use "printVarSummary" often. ****
>>>>>
>>>>> On 11/15/2010 11:45 AM, sbasu@iarc.uaf.edu wrote:
>>>>>> Hello,
>>>>>>
>>>>>> I am trying to calculate the vertical gradient of potential
>>>>>> temperature
>>>>>> and zonal wind. I am trying to use 'center_finite_diff_n' method in
>>>>>> NCL.So
>>>>>> far I am able to plot d(pt)/dp, pt-potential temp. Is it possible to
>>>>>> calculate du/dz and d(pt)/dz by this method ?
>>>>>> My dataset is standard output from CAM 3.1_p2 output files. I am
>>>>>> attaching
>>>>>> the script I am using.
>>>>>> I am getting this error:
>>>>>> fatal:center_finite_diff_n: r must either be a scalar, a 1D array
>>>>>> the
>>>>>> same
>>>>>> length as the dim-th dimemsion of q, or the same size as q
>>>>>> fatal:Execute: Error occurred at or near line 58 in file
>>>>>> baroclinincity_Xseries5.ncl
>>>>>>
>>>>>> Thanks,
>>>>>> Soumik
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> ncl-talk mailing list
>>>>>> List instructions, subscriber options, unsubscribe:
>>>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>>
>>>>>
>>>>> --
>>>>> ======================================================
>>>>> Dennis J. Shea tel: 303-497-1361 |
>>>>> P.O. Box 3000 fax: 303-497-1333 |
>>>>> Climate Analysis Section |
>>>>> Climate& Global Dynamics Div. |
>>>>> National Center for Atmospheric Research |
>>>>> Boulder, CO 80307 |
>>>>> USA email: shea 'at' ucar.edu |
>>>>> ======================================================
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> ======================================================
>>> Dennis J. Shea tel: 303-497-1361 |
>>> P.O. Box 3000 fax: 303-497-1333 |
>>> Climate Analysis Section |
>>> Climate& Global Dynamics Div. |
>>> National Center for Atmospheric Research |
>>> Boulder, CO 80307 |
>>> USA email: shea 'at' ucar.edu |
>>> ======================================================
>>>
>>
>>
>
>
> --
> ======================================================
> Dennis J. Shea tel: 303-497-1361 |
> P.O. Box 3000 fax: 303-497-1333 |
> Climate Analysis Section |
> Climate & Global Dynamics Div. |
> National Center for Atmospheric Research |
> Boulder, CO 80307 |
> USA email: shea 'at' ucar.edu |
> ======================================================
>

-- 
*************************************
Soumik Basu
Graduate Student, Research Assistant
International Arctic Research Center
University of Alaska Fairbanks
Fairbanks,Alaska,USA
**************************************
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Received on Wed Nov 17 12:05:51 2010

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