[ncl-talk] The problem about the inverse Laplacian function in spherical harmonics

[Hoa Dao]

Hi,

Several days ago, I used the ilapsG function as a step to calculate the
rotational wind and divergent wind, regarding to this online script:
https://www.ncl.ucar.edu/Applications/Scripts/wind_4.ncl
The data I used is Era-Interim reanalysis, and because I forgot to reverse
the latitudinal direction to which from South to North, the results became
weird and full of deformation regions, as follows:

[image: image.png]

I used to have doubts about misusing the Hemholtz equation instead of
Poisson equation to solve the problem, but it wasn't that.
Turns out reversing the latitude direction is the answer, but I don't know
how it works. Can you send me some references and the source code that
contributes to this inverse Laplacian function?  I cannot find the function
source code anywhere (I chose to use the binary installation).
Thank you in advance for your help.

-- 
------------------------------------------------------------------------------------------------------------------------------------
*Dao Nguyen Quynh Hoa*
Contact: +84 (0)125 775 8771
Department of Meteorology
Faculty of Hydrology Meteorology and Oceanography
Hanoi University of Science (HUS) - Vietnam National University (VNU)
No. 334 - Nguyen Trai Str. - Thanh Xuan Distr. - Hanoi - Vietnam
Email: *hoadao0610 at gmail.com <hoadao0610 at gmail.com>*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20181009/59021b7b/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 264456 bytes
Desc: not available
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20181009/59021b7b/attachment-0001.png>