Tropospheric jet response to Antarctic ozone depletion: An update with Chemistry-Climate Model Initiative (CCMI) models

Abstract

The Southern Hemisphere (SH) zonal-mean circulation change in response to Antarctic ozone depletion is re-visited by examining a set of the latest model simulations archived for the Chemistry-Climate Model Initiative (CCMI) project. All models reasonably well reproduce Antarctic ozone depletion in the late 20th century. The related SH-summer circulation changes, such as a poleward intensification of westerly jet and a poleward expansion of the Hadley cell, are also well captured. All experiments exhibit quantitatively the same multi-model mean trend, irrespective of whether the ocean is coupled or prescribed. Results are also quantitatively similar to those derived from the Coupled Model Intercomparison Project phase 5 (CMIP5) high-top model simulations in which the stratospheric ozone is mostly prescribed with monthly-and zonally-averaged values. These results suggest that the ozone-hole-induced SH-summer circulation changes are robust across the models irrespective of the specific chemistry-atmosphere-ocean coupling.

Role of the mean state for the Southern Hemispheric jet stream response to CO2 forcing in CMIP6 models

“…However, Simpson & Polvani (2016) showed that the relationship is restricted to mainly the austral winter half-year, and that the theoretical basis originally proposed by Kidston & Gerber (2010) does not hold. Consistent with Simpson & Polvani (2016), both Seviour et al (2017) and Son et al (2018) found little effect of the mean jet latitude on the December-February jet response to polar stratospheric ozone depletion across different sets of global climate models. Furthermore, it is important to mention that factors other than the mean state also contribute to the uncertainty in the future SH jet response; previous studies have pointed to the roles of changes in the lower-and upper-tropospheric baroclinicity and in the polar stratospheric vortex (e.g.…”

Ozone—climate interactions and effects on solar ultraviolet radiation

“…New studies have reconfirmed these overall effects using different approaches based on observations and models. 68,69 Long-term data records show that changes in tropospheric circulation due to the ozone 'hole' have contributed to a decrease in summer temperatures over southeast and south-central Australia, and inland areas of the southern tip of Africa. 70 In the decades since the appearance of the ozone 'hole', anomalously high (or low) total ozone column amounts in the spring are significantly correlated with hotter (or colder) than normal summers over large regions of the SH.…”

Polar Climate Change as Manifest in Atmospheric Circulation

“…1) [80, 81, 84, 85, 91]. The causal chain for this starts with the fact that ozone absorbs solar radiation, and therefore in sunlit seasons, the depletion of stratospheric ozone induces local radiative cooling of the polar stratospheres [92].…”