Model calculations suggest that PSC-Ia optical properties measured by lidar at ultraviolet and visible wavelengths are strongly correlated; particle depolarization ratios and backscatter coefficients are 17% smaller and 41% larger at a wavelength of 532 nm than at 355 nm, respectively. The model relations are used to compute 532--nm particle backscatter and depolarization ratios from 355--nm lidar data of a PSC Ia--enhanced, i.e., a PSC of type Ia with unusually high backscatter ratios, measured with a UV Raman lidar over Esrange, Sweden (67.9 ¿N, 21.1 ¿E), on 20 Jan 1997. The calculated optical properties agree well with lidar observations at 532 nm of this PSC type. ¿ 2000 American Geophysical Union