An Etymological Dictionary of Astronomy and Astrophysics

The boundary between the → troposphere and → stratosphere. Its height, varying with latitude and seasons,
is from 8 km at poles, to 18 km at equator; it is higher during winter time. The atmospheric temperature decreases from ground upward until the tropopause. Then it increases in stratosphere because of the absorption of solar ultraviolet radiation.

Etymology (EN): → tropo- + pause “break, cessation, stop,” from M.Fr. pause, from L. pausa “a halt, stop, cessation,” from Gk. pausis “stopping, ceasing,” from pauein “to stop, to cause to cease.”

Etymology (PE): From gašt, → tropo-, + marz “frontier, border, boundary” (Mid.Pers. marz “boundary;” Av. marəza- “border, district,” marəz- “to rub, wipe;” Mod.Pers. parmâs “contact, touching” (→ contact), mâl-, mâlidan “to rub;” PIE base *merg- “boundary, border;” cf. L. margo “edge” (Fr. marge “margin”); P.Gmc. *marko;
Ger. Mark; E. mark, margin).