Smoke from Forest Fires in Siberia and Aerosol from Raikoke Volcano in the Stratosphere Above Tomsk in Summer and Autumn 2019

In August 2019, aerosol layers were detected with a ground-based lidar station in the stratosphere above Tomsk (West Siberia) at the altitudes of 10–17 km. Investigation of the origin of these layers is described herein because their source could be the eruption of Raikoke on 21–22 June 2019, or extensive forest fires in eastern Siberia in July–August 2019. It has been demonstrated by means of complex trajectory analysis involving the data obtained from the CALIOP lidar on the CALIPSO satellite that the source of aerosol in the stratosphere above Tomsk at the altitudes of 10–14 km in August 2019 could be fire events in eastern Siberia, while the aerosol at the altitudes of 15–17 km originated from the Raikoke volcano. Only volcanic aerosol was observed in the stratosphere above Tomsk in July. The location and time of the formation of four powerful pyrocumulonimbi (PyroCb) that were able to inject the smoke into the lower stratosphere were determined by using a complex of VIIRS radiometers on the Suomi-NPP satellite and instruments on the Himawari-8 satellite. It has been determined that one of these PyroCb was powerful enough to inject the smoke to an altitude of 14 km. Investigation of the decrease of the maximum values of backscattering ratio in the Northern Hemisphere according to the data from CALIPSO confirms these conclusions. The evolution of the aerosol load in the stratosphere was traced in Tomsk from July to October 2019.