Global Faraday Rotation
Linearly polarised electromagnetic waves passing through the ionosphere have their polarisation rotated, an effect called Faraday rotation (FR). Shown right is the output of a model of FR for P-band radar at the minimum of the sunspot cycle. This diverging data is plotted with GMT's polar palette using the following commands:
PRJ="-JM5i" RNG="-R-180/180/-80/80" grdimage $PRJ fr.grd -Cfr.cpt $RNG -K grdcontour $PRJ fr.grd -Cfr.cpt -A- $RNG -O -K grdcontour $PRJ fr.grd -C10 -A- -L5/15 $RNG -W5 -O -K grdcontour $PRJ fr.grd -C10 -A- -L-15/-5 $RNG -W5 -O -K pscoast $PRJ -Dc -W2 $RNG -O -K psscale -D-2/5/8/0.2 -Cfr.cpt -O -K psbasemap $PRJ $RNG -Bf30a30NEwS -O