A Rayleigh-Raman lidar on And¿ya (69¿N, 16¿E), in northern Norway, was used to monitor aerosols during the Arctic winter 1991/92. Polar stratospheric clouds (PSCs) were detected on four days in January 1992. The observations on Jan. 5 show a PSC apparently at an early stage of development. Fully-developed PSCs were seen on Jan. 8 and 9, covering an altitude range from 18 to 24 km; the cross-polarized returns were high and the parallel returns low, characteristic of type la PSCs. The temperature histories of appropriate air parcels indicates that PSCs were mixed into the Pinatubo aerosol at lower altitudes on Jan. 19. ¿ American Geophysical Union 1994