G. Beyerle et al., TEMPORAL DEVELOPMENT OF MT-PINATUBO AEROSOLS AS OBSERVED BY LIDAR ANDSUN PHOTOMETER AT NY-ALESUND, SPITSBERGEN, Geophysical research letters, 22(18), 1995, pp. 2497-2500
Since summer 1991 multiwavelength lidar and sun photometer observation
s of the Pinatubo aerosol layer are performed at the Arctic NDSC stati
on (Koldewey-Station) in Ny-Alesund, Spitsbergen. The height integrate
d backscatter coefficient and the optical density decrease exponential
ly in time with time constants of 0.89+/-0.39 and 0.94+/-0.37 years, r
espectively. Their wavelength dependence indicates a decrease in media
n particle radii between 1992 and 1993. It is shown that the observati
ons are consistent with results of parameter-free model calculations.
The calculations are based on the assumption that gravitational sedime
ntation is the dominant process for volcanic aerosol removal in the Ar
ctic stratosphere.