An Etymological Dictionary of Astronomy and Astrophysics

The second major layer of Earth’s atmosphere, just above the → troposphere and below the → mesosphere, extending from about 20 km to 90 km above the Earth. It is characterized by little vertical increase in temperature.

Etymology (EN): From Fr. stratosphère, literally “sphere of layers,” coined by Fr. meteorologist Léon-Philippe Teisserenc de Bort (1855-1913) from L. stratus “a spreading out” (from p.p. stem of sternere “to spread out”) + -sphère (→ sphere), as in atmosphère.

Etymology (PE): Cine-sepehr, from Ciné, → stratum, + sepehr, → sphere.