> as lemmas
chemosphere
chemosphere n. 
/ˈkɛməsfɪə/, /ˈkɛməˌsfɪ(ə)r/ a region of the upper atmosphere in which photochemical reactions take place, usually regarded as corresponding to the upper stratosphere and the mesosphere.
Brit. /ˈkiːməsfɪə/
, /ˈkiːməsfɪə//ˈkɛməsfɪə/U.S. /ˈkiməˌsfɪ(ə)r/
, /ˈkiməˌsfɪ(ə)r//ˈkɛməˌsfɪ(ə)r/ΚΠ
1950 Newsweek 16 Oct. 53 Physicist J. Kaplan..revealed that a region 26 to 70 miles above the earth (he called it the ‘chemosphere’) appears to be rich in the hydroxyl molecule.
1957 F. H. Forrester 1001 Questions answered about Weather ii. 22 The chemosphere is a layer of considerable chemical activity involving the breakup of water and carbon dioxide molecules by short-wave radiation.
1996 E. Ramsden Chem. of Environment ii. 9 The mesosphere (sometimes called the chemosphere) has very low concentrations of species that can absorb radiation.
2000 H. F. Hemond & E. J. Fechner-Levy Chem. Fate & Transport in Environment (ed. 2) iv. 284 The upper portion of the stratosphere is considered part of the chemosphere because much of the absorbed energy initiates chemical reactions.
<
as lemmas