Airborne lidar observations of Arctic polar stratospheric clouds: Indications of two distinct growth stages

Abstract

Airborne lidar observations of Arctic polar stratospheric clouds (PSCs) during January 1984 and January 1986 show constrast suggestive of two distinct PSC growth stages delineated by the frost‐point temperature. Results obtained at temperatures 2–6K above the frost point indicate a stage of significant, but limited, particle growth such as proposed in recent models of PSC formation by co‐deposition of HNO 3 and H 2 O vapors. Results obtained at a temperature near the frost point indicate the formation of somewhat larger crystalline particles.