We present a climatological model of the extinction coefficient of stratospheric aerosols in the UV-visible range based on SAGE II data. The model is a function of wavelength, latitude, relative altitude with respect to the tropopause and depends on the volcanism level. The vertical structure describes the tropopause region, the Junge layer and the high altitude domain. The model is shown to predict realistic extinction profiles with an reasonable accuracy. ¿ 1999 American Geophysical Union