[ncl-talk] plot model variable without knowledge of map projection?

[Erik Noble]

Dear NCL,
How can I plot a model variable on a grid without knowing the native grid's
particular map projection? I would like to see an image similar to what
"ncview" does when I look at the file (image attached). NCVIEW seems to
just know what to plot.
Although I am able to extract the variable, I can't seem to plot it
correctly at all. How do I show a decent map?
Thank you,
- Erik -


[image: Inline image 2][image: Inline image 1]


load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
; Get file
a=addfile("ICE.2012.01-12.f06.nc","r")
; Get variable
; and lat-lons (2D)
s1=a->SHF
printVarSummary(s1) ; display variable
lat2d    = a->LAT
lon2d    = a->LON
s1 at lat2d=lat2d
s1 at lon2d=lon2d
printVarSummary(s1) ; display variable again

; plot paramaters
res = True
wks = gsn_open_wks("x11"  ,"x_static")
res at pmTickMarkDisplayMode = "Always"         ; turn on lat / lon labeling
;************************************************
; set map limits
;************************************************
dimll = dimsizes(lat2d)
nlat  = dimll(0)
mlon  = dimll(1)
; res at mpProjection          = ??? I HAVE NO IDEA???
res at mpLimitMode           = "Corners"
res at mpLeftCornerLatF      = lat2d(0,0)
res at mpLeftCornerLonF      = lon2d(0,0)
res at mpRightCornerLatF     = lat2d(nlat-1,mlon-1)
res at mpRightCornerLonF     = lon2d(nlat-1,mlon-1)
res at tfDoNDCOverlay        = True             ; True only for 'native' grid
res at gsnAddCyclic          = False  ; data are not cyclic
; res at lbLabelAutoStride     = True ; let NCL determine label bar spacing
plot = gsn_csm_contour_map (wks,s1(0,:,:),res)

; TERMINAL OUTPUT

erikmbp:MAR_3.2 enoble$ ncl test_plot_080714.ncl
 Copyright (C) 1995-2014 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 6.2.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.

Variable: s1
Type: float
Total Size: 9662400 bytes
            2415600 values
Number of Dimensions: 3
Dimensions and sizes: [TIME | 366] x [Y18_127 | 110] x [X10_69 | 60]
Coordinates:
            TIME: [972672.0625..981432]
            Y18_127: [-1200.000091097248..1525.000107494753]
            X10_69: [-775.0000471284118..700.0000440380242]
Number Of Attributes: 3
  units : W/m2
  long_name : Sensible Heat Flux
  history : From ICE.j06.2012.01.01-15

Variable: s1
Type: float
Total Size: 9662400 bytes
            2415600 values
Number of Dimensions: 3
Dimensions and sizes: [TIME | 366] x [Y18_127 | 110] x [X10_69 | 60]
Coordinates:
            TIME: [972672.0625..981432]
            Y18_127: [-1200.000091097248..1525.000107494753]
            X10_69: [-775.0000471284118..700.0000440380242]
Number Of Attributes: 5
  lon2d : <ARRAY of 6600 elements>
  lat2d : <ARRAY of 6600 elements>
  units : W/m2
  long_name : Sensible Heat Flux
  history : From ICE.j06.2012.01.01-15
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