National Oceanic and
Atmospheric Administration
United States Department of Commerce

Polar Stereographic Plots

Polar Stereographic Plots

Question:

How can I make publication-quality Polar Stereographic Plots?

Example:

 

The plots shown in this FAQ are made with PyFerret, using the arial font and saved as .png images

 

> pyferret
yes? set text/font=arial
yes? ... ! continuing with the commands shown below.

...
yes? FRAME/file=plotfile_name.png

 

For an introduction to the map projection scripts, run

yes? go mp_demo

Scripts such as mp_aspect, mp_fland, mp_land, mp_graticule, and mp_label are tools for customizing map projection plots. The above figure was made with these commands:

 SET WIN/SIZ=0.6
 PPL dfltfnt CR
 USE coads_climatology
 SET grid sst

 ! Define a region in the northern hemisphere.

 SET REGION/X=0:360/Y=11:90/L=1

 ! Set up the map projection parameters and apply the
 ! correct aspect ratio.

 GO mp_stereographic_north 180 50
 GO mp_aspect

 LET masked_sst = sst * mp_mask

 ! Plot the data, add land mask and land outline

 FILL/NOAXES/NOLAB masked_sst, x_page, y_page

 GO mp_fland 20
 GO mp_land

 ! Mark latitude and longitude with a graticule.

 GO mp_graticule

 ! Add labels in world coordinates.

 go mp_label 10 10 1 0 .15 "COADS Climatology Data"
 go mp_label 180 6 0 0 0.2 "January SST"

The next plot illustrates more techniques using a section of the hemisphere.The Ferret command script to create the plot is mp_stereo_demo.jnl.

 

Reference Material:

There are a number of helpful scripts that will let you control the appearance of plots that use map projections. To see a list of the scripts with brief descriptions, at the system prompt type

 

> Fgo "mp_"

They are also listed in the Users Guide, Chapter 1, "Go Tools". See "map projection scripts" in the index.

Please also see these related FAQ's: