Seasonal and annual variations of aerosol concentrations in the troposphere and stratosphere over Syowa Station observed by a balloon-borne optical particle counter

Abstract

This report summarizes observations of tropospheric and stratospheric aerosols by a balloon-borne optical particle counter (Aerosol sonde) performed at Syowa Station from April 1997 to January 2008. Typical seasonal changes in the stratospheric aerosol layer were characterized by sedimentations of the stratospheric aerosol layer in autumn, PSCs activity in winter, and sudden increase in aerosol concentration at the end of spring. The annual change shows that the perturbations of stratospheric aerosol caused by the eruption of Mt. Pinatubo in 1991 remained until 1999. Additionally, seasonal variation of tropospheric aerosol shows clear differences between concentrations from January to June and those from July to December.