Trajectory Analysis of Variations in Ozone-Active Components inside the Stratospheric Arctic Vortex Using M2-SCREAM Reanalysis Data

Thermodynamic and chemical processes inside the stratospheric polar vortex which decrease the ozone content in this region are studied. The winter-spring seasons in the Arctic, with the strongest stratospheric vortices and, hence, maximal ozone loss, are considered. The vortex-averaged variations in ozone and ozone-active components are studied on the basis of an ensemble of backward trajectories inside the vortex and M2-SCREAM stratospheric reanalysis data, which includes some chemical components that affect the ozone concentration. The record ozone depletion in winter 2020 was shown to be due to not only the long-lived stable stratospheric polar vortex, but also the earlier transformation of chlorine reservoirs into the active form and stronger denitrification and dehydration of air masses. The approach suggested can be used to analyze dynamic and chemical processes in the polar stratosphere over past winters and to validate chemical-climate models.