Two lidar stations of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, recorded pronounced aerosol layers in the stratosphere over Tomsk on February 5 and 6, 2025. The analysis of lidar and additional meteorological information showed the occurrence of a rather rare phenomenon for middle latitudes, i.e., polar stratospheric clouds, at that time. The constructed back trajectories of air masses at the altitudes of the formation of polar stratospheric clouds over Tomsk showed that abnormally cold air masses were brought from the polar regions of Norway and Greenland. The results can be useful for specialists in atmospheric physics, climatology, and environmental protection.
Nevzorov et al. (Sun,) studied this question.