[ncl-talk] overlay standardized Geopotential height

[Buzan, Jonathan]

Hi NCL-Talk,

I am attempting to overlay contours of standardized Geopotential height over changes in standardized Geopotential height. All I want to have in the overlay is a zone of positive and a zone of negative values. But I am having trouble understand how this is working. Especially since the contour intervals do not make sense (in the example below).

Cheers,
-Jonathan


Code snippets.
; generate positive and negative zone
PI_Z_rmMean_contrained = PI_Z_rmMean
PI_Z_rmMean_contrained = where(PI_Z_rmMean.ge.80..or.PI_Z_rmMean.lt.-80.,PI_Z_rmMean,PI_Z_rmMean at _FillValue)

     res1 at cnLevelSelectionMode = "ExplicitLevels"
     res1 at cnLevels =  (/-160.,-80.,80.,160./) ; Diffs
     res1 at gsnContourNegLineDashPattern = 1       ; sets negative contours to dash pattern 1
     res1 at cnLineThicknessF = 1.

     plotPI = gsn_csm_contour(wks,PI_Z_rmMean(0,0,:,:),res1)

    plotLGMvsPI = gsn_csm_contour_map(wks,LGM100_vs_PI(0,0,:,:),res)
    overlay(plotLGMvsPI,plotPI)
    plotTemp(0) = plotLGMvsPI
[cid:63425CDA-8356-41D2-971E-9493CA327793 at unibe.ch]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20210707/5369c750/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 2021-07-07 at 4.18.42 PM.png
Type: image/png
Size: 548611 bytes
Desc: Screen Shot 2021-07-07 at 4.18.42 PM.png
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20210707/5369c750/attachment-0001.png>