Anti‐Correlation between stratospheric aerosol extinction and the Ångström parameter from multiple wavelength measurements with SAGE II—A characteristic of the decay period following major volcanic eruptions

Abstract

Stratospheric Aerosol and Gas Experiment (SAGE) II data at multiple wavelengths were analyzed to show how aerosol extinction decays with time following major volcanic eruptions. Comparisons were made between the lowest background level in 1999 and the past data record of the stratospheric aerosol layer. The time variation of the extinction coefficients was compared with the Ångström parameter, which is a good indicator of particle size. A clear anti‐correlation was found between the extinction and the Ångström parameter after the eruption of Mt. Pinatubo. Comparison of the extinction coefficients and Ångström parameters in 1989 and 1999 made it clear that the aerosol layer was affected by volcanic eruptions in 1989. The distinguishing negative correlation is a characteristic feature of decay periods following volcanic eruptions.