RT Journal Article
T1 Future trends in stratosphere-to-troposphere transport  in CCMI models
A1 Ábalos Álvarez, Marta
A1 Orbe, Clara
A1 Kinnison, Douglas E.
A1 Plummer, David
A1 Oman, Luke D.
A1 Jöckel, Patrick
A1 Morgenstern, Olaf
A1 Garcia, Rolando R.
A1 Zeng, Guang
A1 Stone, Kane A.
A1 Dameris, Martin
AB One of the key questions in the air quality and climate sciences is how tropospheric ozone concentrations will change in the future. This will depend on two factors: changes in stratosphere-to-troposphere transport (STT) and changes in tropospheric chemistry. Here we aim to identify robust changes in STT using simulations from the Chemistry Climate Model Initiative (CCMI) under a common climate change scenario (RCP6.0). We use two idealized stratospheric tracers to isolate changes in transport: stratospheric ozone (O_(3)S), which is exactly like ozone but has no chemical sources in the troposphere, and st80, a passive tracer with fixed volume mixing ratio in the stratosphere. We find a robust increase in the tropospheric columns of these two tracers across the models. In particular, stratospheric ozone in the troposphere is projected to increase 10 %–16 % by the end of the 21st century in the RCP6.0 scenario. Future STT is enhanced in the subtropics due to the strengthening of the shallow branch of the Brewer–Dobson circulation (BDC) in the lower stratosphere and of the upper part of the Hadley cell in the upper troposphere. The acceleration of the deep branch of the BDC in the Northern Hemisphere (NH) and changes in eddy transport contribute to increased STT at high latitudes. These STT trends are caused by greenhouse gas (GHG) increases, while phasing out of ozone-depleting substances (ODS) does not lead to robust transport changes. Nevertheless, the decline of ODS increases the reservoir of ozone in the lower stratosphere, which results in enhanced STT of O3S at middle and high latitudes. A higher emission scenario (RCP8.5) produces stronger STT trends, with increases in tropospheric column O_(3)S more than 3 times larger than those in the RCP6.0 scenario by the end of the 21st century.
PB European Geosciences Union
SN 1680-7316
YR 2020
FD 2020-06-11
LK https://hdl.handle.net/20.500.14352/108232
UL https://hdl.handle.net/20.500.14352/108232
LA eng
NO Abalos, M., Orbe, C., Kinnison, D. E., Plummer, D., Oman, L. D., Jöckel, P., Morgenstern, O., Garcia, R. R., Zeng, G., Stone, K. A., and Dameris, M.: Future trends in stratosphere-to-troposphere transport in CCMI models, Atmos. Chem. Phys., 20, 6883–6901, https://doi.org/10.5194/acp-20-6883-2020, 2020.
NO Program Atracción de Talento de la Comunidad de Madrid (fund no. 2016-T2/AMB-1405) Spanish National Project STEADY (project no. CGL2017-83198-R).
NO Comunidad de Madrid
NO Ministerio de Economía y Competitividad (España)
DS Docta Complutense
RD 29 jun 2025