Lidar observations of the stratospheric aerosol scattering at S¿o Jos¿ dos Campos (23¿S, 46¿W) show a very large increase in the stratospheric aerosol burden to have occurred in mid-1982. Peak scattering ratios greater than 5 have been observed, as compared with pre-enhancement values between 1.1 and 1.2, representing an increase by more than an order of magnitude in particulate scattering. It is concluding that the main source of the dust was the eruption of El Chich¿n in Mexico in late March and early April of 1982.