Abstract

The eruption effect on stratospheric aerosol was first observed during lidar sounding at Obninsk station (55°N, 37°E ) in 37 days following the eruption, 22 of July , 1991. The devices used for sounding are described in [1]. The speed of cloud movement, computed on the given measurements, has been found to be more than 1 degree per twenty four hours. 21 of February, 1992 the integral backscatter reached the value 3,67 10⁻³ Br⁻¹ ( the measurements were carried out at the wavelength of 532 nm ) in the layer of 15-30 km and than began to decrease. According to preliminary results the time of relaxation of the stratospheric aerosol in latitude 55°North is close to 10 months, i.e. just less than the relaxation time of the stratospheric aerosol formed following volcano El Chichon in 1982.

© 1993 Optical Society of America