The Stratospheric Aerosol Measurement II (SAM II) satellite experiment measures 14 daily 1.0-&mgr;m aerosol extinction profiles in the high northern latitudes. These SAM II data were used to spot the locations of polar stratospheric clouds (PSCs) and provide an overview of the vertical structure of the upper tropospheric and stratospheric aerosols during the 1989 Airborne Arctic Stratospheric Expedition (AASE). Contour plots of aerosol extinction vs. longitude and altitude are shown for 24 days during AASE which summarize these measurements. PSC sightings occurred during the first week of January and from January 18 through February 2, 1989. Although SAM II measured a higher than average number of PSCs in January 1989 as compared to the previous 10 years, the number of PSCs sighted during the entire 1989 winter season is only slightly above average. Also discussed is the vertical gradient in aerosol extinction which occurs as the SAM II measurement locations cross the polar vortex. ¿ American Geophysical Union 1990