Chlorine Oxide as an Indicator of Ozone Destruction in the Winter–Spring Arctic Stratosphere Based on Aura MLS Observations

The ozone behavior in the Arctic is a major recent concern. The ozone anomalies recur every five years on average. The last, record strong decrease of the ozone level in the stratosphere of the Arctic was recorded in March–April 2020. In February 2022, ozone destruction developed according to a scenario very similar to the anomaly of 2020. Like in 2020, in 2022 the ClO mixing ratio, which can be considered a reliable indicator of ozone destruction, strongly increased after the return of sunlight to the Arctic latitudes, but the subsequent ozone depletion process was halted by a sudden major stratospheric warming on March 20, 2022. In this work, we analyze the ozone destruction in 2020–2022 based on measurements of the total ozone content over 2003–2022 from the TEMIS service, profiles of the air temperature and ozone mixing ratio for 2005–2022 and of ClO mixing ratio for 2020–2022 from Aura MLS observations. The following sites are considered: Eureka, Canada; Ny-Ålesund, Norway; Thule, Greenland; and Resolute, Canada. A relationship is revealed between ozone and chlorine oxide contents. High coefficients of correlation between oscillations of the above parameters at about the same altitudes of their recording, as well as between the total O₃ and ClO contents calculated from their profiles, indicate their close interrelation. Hence, the ClO concentration and total content can be used as indicators of ozone destruction in the Arctic stratosphere.