# Re: how to calculate wind curvature

From: Xi Chang <xi.chang01_at_nyahnyahspammersnyahnyah>
Date: Thu Sep 05 2013 - 07:34:51 MDT

I did something like this

dudp = center_finite_diff_n (u,level,False,0,1) ;level in hPa
(1-1000)
du2dp2 = center_finite_diff_n (dudp,level,False,0,1)

however why the values are quite small....I am really doubtful with this
result.

ncl 27> printMinMax(dudp,True)
(0)
(0) * min=-18.8805 max=19.0047*
ncl 28> printMinMax(du2dp2,True)
(0)
(0) *min=-10.1969 max=11.0823*

Do i make a mistake to calculate this in pressure height coordinate?

Thank you
Xi

On Wed, Sep 4, 2013 at 5:25 PM, Dennis Shea <shea@ucar.edu> wrote:

> Use 'center_finite_diff' twice
>
> http://www.ncl.ucar.edu/**Document/Functions/Built-in/**
> center_finite_diff.shtml<http://www.ncl.ucar.edu/Document/Functions/Built-in/center_finite_diff.shtml>
>
>
> On 9/4/13 4:10 AM, Xi Chang wrote:
>
>> Anyone has an experience to calculate vertical wind curvature in NCL.
>> it is a second derivative of zonal wind in which curvature defined as
>> (d2u/dz2)
>>
>> thank you
>>
>> Xi
>>
>>
>>
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Received on Thu Sep 5 07:35:00 2013

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