U. S. Report to the IUGG, 1979–1982: Solar‐planetary relationships—Aeronomy

Aeronomy is the study of the physics and chemistry of the upper atmosphere. The upper atmosphere is usually defined as the region of the atmosphere above the tropopause extending upward to the point where electric and magnetic fields dominate the phenomena rather than the atmospheric atoms and molecules. The lower part of this region, from about 10 to 90 kilometers altitude, has become known as the middle atmosphere. An international program called MAP (Middle Atmosphere Program) is now underway to intensively study this region.