An isotherm is a line of equal or constant temperature on a graph, plot, or map; an isopleth of temperature. For example, isotherms are commonly seen on weather maps to show large-scale temperature distributions.
Drawing Contour Plots (http://avc.comm.nsdlib.org/cgi-bin/wiki_print.pl?Drawing_Contour_Plots). A lesson plan that deals with drawing various isopleths including isotherms.
... 60 aircraft for Greece; with an order for 24 units from Austria pending.
In British service, the aircraft is supposed to replace the Tornado F3 and the Jaguar GR3A[?]. ...