Evaluating stratospheric ozone and water vapour changes in CMIP6 models from 1850 to 2100

摘要: Abstract. Stratospheric ozone and water vapour are key components of the Earth system, past future changes to both have important impacts on global regional climate. Here we evaluate long-term in these species from pre- industrial (1850) end 21st century CMIP6 models under a range emissions scenarios. There is good agreement between CMIP multi-model mean observations, although there substantial variation individual models. For mean, total column (TCO) has increased ∼300 DU 1850 ∼305 1960, before rapidly declining 1970s 1980s following use emission halogenated depleting substances (ODSs). TCO projected return 1960s values by middle SSP2-4.5, SSP3-7.0, SSP4-3.4, SSP4-6.0 SSP5-8.5 scenarios, SSP3-7.0 scenarios be ∼10 higher than 2100. However, SSP1-1.9 SSP1-1.6 not despite reductions ODSs due decreases tropospheric mixing ratios. This pattern similar patterns, except tropics where most values, either through SSP1-2.6, or lower stratospheric resulting an acceleration Brewer-Dobson Circulation other SSPs. ratios tropical stratosphere ∼0.5 ppmv pre-industrial present day increase further century. The largest increases (∼2 ppmv) simulated with highest assumed forcing pathway (e.g. SSP5-8.5). Both show large variability explosive volcanic eruptions.