It is proposed that stratosphere shall signify solely the nearly isothermal region above the troposphere; that the layer between the stratosphere and the deep temperature minimum somewhat below 100 km be called the mesosphere; that the layer of rising temperature over this minimum be called the thermosphere. On the basis of composition, it is proposed to divide the atmosphere into the homosphere (of substantially uniform composition from the ground upwards) and the heterosphere (of different composition). On the basis of electron density, a correlative to ionosphere is proposed, the neutrosphere. Using pause to signify upper boundary, the stratopause, mesopause, homopause and neutropause are defined. Peak is suggested as the name for a level of maximum, e.g., mesopeak, ozone peak, E or F peak. Incline and decline are names suggested for the parts of a peaked layer below and above the peak, e.g., mesoincline (for the layer of rising temperature just above the stratosphere), mesodecline, E or F incline or decline. A “dip” in a peaked layer is called a syncline.
* Research Associate, California Institute of Technology, under Signal Corps Project No. 24–172B; on leave from Oxford University.