Re: Trying to calculate vertical wind shear

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Tue Nov 16 2010 - 11:28:52 MST

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
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>>
>>
>> --
>> ======================================================
>> 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 |
======================================================
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Received on Tue Nov 16 11:28:58 2010

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