The SAGE (Stratospheric Aerosol and Gas Experiment) satellite aerosol extinction profiles at 1.0 and 0.45 μm, averaged over 10¿ latitude bands, are used to derive a description of the background stratosphere, which is compared to the Standard Radiation Atmosphere model. At middle and high latitudes a small seasonal variation appears, with larger particles and higher optical depths in winter. ¿American Geophysical Union 1987