[gradsusr] Calculation of zonal gradient

[Lopez, Hosmay]

Dear Lynda,


pi = 2*math_asin(1)

'define dlon = cdiff(lon,x)*'pi'/180)'

'define coslat = cos(lat*'pi'/180)'

'define dudx = cdiff(u,x)/(6.37e6*coslat*dlon)'


Best,

Hosmay



________________________________
From: gradsusr <gradsusr-bounces at gradsusr.org> on behalf of Lyndz <olagueralyndonmark429 at gmail.com>
Sent: Thursday, February 7, 2019 7:04 AM
To: GrADS Users Forum; Jeff Duda
Subject: [gradsusr] Calculation of zonal gradient

Dear GrADS-experts,

I am trying to calculate the zonal gradient of U-wind component using the cdiff() function.
Below is part of the script that calculates this.


'define dx = cdiff(lon,x)*3.1416/180'
'define du = cdiff(u*cos(lat*3.1416/180),y)'
'define grad=(du/dx)*(6.37e6*cos(lat*3.1416/180))*1e-8'

 I would like to ask if this is correct. I am still confused how to get the correct dx here.

I'll appreciate any help.

Sincerely,

--Lyndz
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