Arctic ozone depletion in 2019/20: Roles of chemistry, dynamics and the Montreal Protocol ...

• Main Author: Santee, Michelle
• Format: Dataset
• Language: unknown
• Published: Root 2023
• Subjects: Arctic
• Online Access: https://dx.doi.org/10.48577/jpl.qlrmhk; https://dataverse.jpl.nasa.gov/citation?persistentId=doi:10.48577/jpl.QLRMHK

We use a three-dimensional chemical transport model and satellite observations to investigate Arctic ozone depletion in winter/spring 2019/20 and compare with earlier years. Persistently, low temperatures caused extensive chlorine activation through to March. March-mean polar-cap-mean modeled chemical column ozone loss reached 78 DU (local maximum loss of ∼108 DU in the vortex), similar to that in 2011. However, weak dynamical replenishment of only 59 DU from December to March was key to producing very low (<220 DU) column ozone values. The only other winter to exhibit such weak transport in the past 20 years was 2010/11, so this process is fundamental to causing such low ozone values. A model simulation with peak observed stratospheric total chlorine and bromine loading (from the mid-1990s) shows that gradual recovery of the ozone layer over the past 2 decades ameliorated the polar cap ozone depletion in March 2020 by ∼20 DU. ...