Abstract
After a brief review of current theoretical works to estimate the climatic impact of volcanic activities, it is shown that the observation by laser radar is very useful to obtain important information of stratospheric volcanic clouds. The observed results of stratospheric aerosols by laser radar over Fukuoka for the period from November 1979 through March 1982 are shown in some detail. The transport and dispersion of eiecta from various volcanic eruptions are discussed. It is shown that significant increases of stratospheric aerosols occurred once every year. But the increase of the optical depth of the stratospere at the wavelength 0.55μm for the period is less than 0.01, which alone has negligible impact on the global surface temperature. During the period the average temperature in the northern hemisphere decreased by about 0.5℃. Possible casual relationship of the events is speculated.
