| Autor: |
Iglesias-Suarez, Fernando, Wild, Oliver, Kinnison, Douglas E., Garcia, Rolando R., Marsh, Daniel R., Lamarque, Jean-François, Ryan, Edmund M., Davis, Sean M., Eichinger, Roland, Saiz-Lopez, Alfonso, Young, Paul J. |
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| Zdroj: |
Geophysical Research Letters; 6/16/2021, Vol. 48 Issue 11, p1-10, 10p |
| Abstrakt: |
Observational and modeling evidence suggest a recent acceleration of the stratospheric Brewer-Dobson circulation (BDC), driven by climate change and stratospheric ozone depletion. However, slowly varying natural variability can compromise our ability to detect such forced changes over the relatively short observational record. Using observations and chemistry-climate model simulations, we demonstrate a link between multi-decadal variability in the strength of the BDC and the Interdecadal Pacific Oscillation (IPO), with knock-on impacts for composition in the stratosphere. After accounting for the IPO-like variability in the BDC, the modeled trend is approximately 7%-10% dec-1 over 1979-2010. Furthermore, we find that sea surface temperatures explain up to 50% of the simulated decadal variability in tropical mid-stratospheric ozone. Our findings demonstrate strong links between low-frequency variability in the oceans, troposphere and stratosphere, as well as their potential importance in detecting structural changes in the BDC and future ozone recovery. Plain Language Summary Natural variability is a key element of the climate system and can mask human-induced changes. Here, we are interested in the naturally varying strength of the stratospheric global circulation and how this impacts the composition of the stratosphere. Using observations and model simulations, we show that slowly changing (multi-decadal) natural variability in the Pacific Ocean is reflected in the stratospheric circulation. This link helps us to better understand structural changes in the stratospheric circulation arising due to human interferences. In turn, slow transport variability reconciles recent low levels of ozone in the middle tropical stratosphere, which otherwise are in disagreement with the expected ozone recovery. These results have implications for both reconciling theory and observed changes in the stratospheric circulation, as well as better understanding the rate of stratospheric ozone recovery. [ABSTRACT FROM AUTHOR] |
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Complementary Index |
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