Polar vortex meandering and stratospheric aerosol distribution: Lidar measurements at Fairbanks, Alaska (scientific paper)

Abstract

Lidar measurements at Fairbanks, Alaska (64°49' N, 147°52' W) and Ny-Aalesund, Norway (78°54'N, 11°53'E) in December 1991 and January, 1994, respectively, was made to monitor distribution of stratospheric aerosols. The location of Fairbanks lidar site is advantageous to see the effect of polar vortex wall to stratospheric aerosol density distribution since the lidar site is near the polar vortex wall, and sometimes inside and sometimes outside of the polar vortex owing meandering motion of polar vortex. Lidar site of Ny-Aalesund is usually inside of the polar vortex in winter. Comparison of measurements at Fairbanks and Ny-Aalesund showed that polar vortex meandering disturbed profiles of stratospheric aerosol content. Comparing measurements at Fairbanks and Toyokawa, Japan (34°45' N, 137°24' E) the measurements at Fairbanks are well corresponding to the long tens trend observed at Toyokawa, and noticeable day-to-day variations in aerosol content, integrated backscattering coefficient of stratospheric particulate matter, in winter of 1993/1994, which possibly due to the polar atmospheric effect, are detected in the Fairbanks data. Above about 20 km there was little aerosol content when the lidar station was inside of polar vortex. Large enhancement of aerosol load near the local tropopause was observed, which may associate with aerosol descending from the stratosphere to the troposphere near the wall of polar vortex.