[ncl-talk] Contour over map - projection issue

[Michele Petrini]

Dear helping desk,
I am a beginner with NCL and I have the following issue. I have a netcdf 
file with some data obtained from an ice sheet model run. The model 
transforms latitude-longitude coordinates into native Cartesian 
distances coordinates via the Lambert equal Area projection, using as a 
center of projection the North Pole (0,90). Hence my data in the netcdf 
file are geographically dependent on native Cartesian distances 
coordinates. I am trying now to plot a contour over a map of the 
Northern Emisphere of one of the netcdf file variables (let's say the 
ice thickness). First of all, I imported succesfully the variables I am 
interested to, depending on time, x and y, along with the latitude and 
longitude variables, on x and y (where x and y are defined in native 
Cartesian distances from (0,90). In order to go back from the native 
Cartesian distances to latitude and longitude, I define a new array 
/without /attributes (if the original variable is H, I just insert 
Hlatlon= (\ H \)). Then I name the three dimensions of the new variable 
Hlatlon (time, lat, lon), and I assign to the dimension number 1 and 2 
(using the NCL enumeration from 0) the coordinate variables lat and lon. 
Finally, I plot the contour of ice thickness over the map. What I get 
when I run the script is wrong (I'm sure as, for instance, Greenland is 
ice free). Where I did wrong? Is there a better (faster or more correct) 
way to plot my contour with such variables?
Thank you for your help,

Michele

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***
Michele Petrini

Ph.D. student in Earth Science and Fluid Mechanics

Università degli studi di Trieste,
Dipartimento di Matematica e Geoscienze
Palazzina C - via Weiss 1, 34128 Trieste, Italy

Email: mpetrini139 at yahoo.it
Skype: michele.petrins
Mobile: +39 3398367372

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