Lagrange Studies of Anomalously Stable Arctic Stratospheric Vortex Observed in Winter 2019–2020

We present the results of applying the Lagrangian methods to study the fine dynamic structure of the stratospheric polar vortex in the winter–spring of 2019–2020. Characteristics of the vortex structure for this winter are compared with those of a strong polar vortex and the winter of 2018–2019, when the vortex was weak. Due to the low activity of planetary waves, the polar vortex in 2019–2020 remained stable until the end of April, which created the conditions for record ozone destruction in the Arctic. We present variations of the horizontal dynamic structure obtained using reverse domain filling (RDF) and the vortex strength represented as an M function depending on time and altitude. Variations in ozone and thermodynamic parameters averaged over the ensemble of trajectories inside the vortex using the ERA5 reanalysis data are also presented.