Long-term Trends in the BDC and Ozone: Importance of Two-way Interactions

The importance of two-way interactions between ozone and the Brewer-Dobson circulation (BDC) for long-term trends will be revised in light of recent work. First, we will provide evidence of the key role played by the ozone hole in driving past trends in the BDC and show that models project a weaker acceleration in the future due to the reduction of stratospheric ozone depletion. Then, we will examine the trends in stratosphere-to-troposphere transport over the 21^st century, largely driven by the enhanced BDC, and discuss the implications for the future evolution of ozone in the troposphere.