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Arctic Ozone Depletion in 2019/20: Roles of Chemistry, Dynamics and the Montreal Protocol
Author(s) -
Feng Wuhu,
Dhomse Sandip S.,
Arosio Carlo,
Weber Mark,
Burrows John P.,
Santee Michelle L.,
Chipperfield Martyn P.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl091911
Subject(s) - ozone depletion , ozone , ozone layer , montreal protocol , polar vortex , atmospheric sciences , chemical transport model , arctic , polar , stratosphere , bromine , climatology , environmental science , chlorine , meteorology , chemistry , oceanography , geology , physics , organic chemistry , astronomy
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.