Characteristics of stratospheric aerosol from data of lidar measurements over Obninsk in 2012–2015

Resumo

Lidar polarization measurements of stratospheric aerosol were performed over Obninsk in 2012–2015. In all, over 300 altitude profiles of the aerosol backscattering coefficient at a wavelength of 532 nm in the altitude interval from 10 to 40 km were obtained. Overall, the measured aerosol backscattering characteristics are close to the known background values. During spring 2013, an elevated content of spherical-type aerosol was noted in the tropopause region, seemingly associated with sedimentation of aerosol structures formed during the fall of the Chelyabinsk meteorite. In July 2014 and 2015, layers of increased aerosol scattering were observed in the altitude interval from 10 to 15 km, associated with transcontinental transport of aerosol from Canadian forest fires. Integrated backscattering and extinction characteristics are estimated for the lower (from tropopause level to 15 km) and middle (from 15 to 30 km) stratospheric layers. It is found that the contribution of the lower layer to these optical characteristics is 1.8 and 1.6 times larger than the contribution of the middle layer.