Principal Component Analysis (PCA) aerosol retrievals have been applied to multiwavelength lidar measurements made in early 1995 in the Canadian Arctic. The lidar data have been inverted to provide estimates of stratospheric aerosol volume, surface area, effective radius, and sulfate mass mixing ratio. Above the vortex lower boundary the aerosol parameters were relatively constant but changed notably in the sub-vortex region throughout the winter. ¿ 1998 American Geophysical Union