RT Journal Article
T1 Driving mechanisms for the El Niño-Southern Oscillation impact on stratospheric ozone
A1 Benito Barca, Samuel
A1 Calvo Fernández, Natalia
A1 Ábalos Álvarez, Marta
AB While the impact of the El Niño–Southern Oscillation (ENSO) on the stratospheric circulation has been long recognized, its effects on stratospheric ozone have been less investigated. In particular, the impact on ozone of different ENSO flavors, eastern Pacific (EP) El Niño and central Pacific (CP) El Niño, and the driving mechanisms for the ozone variations have not been investigated to date. This study aims to explore these open questions by examining the anomalies in advective transport, mixing and chemistry associated with different El Niño flavors (EP and CP)andLaNiñaintheNorthern Hemisphere in boreal winter. For this purpose, we use four 60-year ensemble members of the Whole Atmospheric Community Climate Model version 4. The results show a significant ENSO signal on the total column ozone (TCO) during EP El Niño and La Niña events. During EP El Niño events, TCO is significantly reduced in the tropics and enhanced at middle and high latitudes in boreal winter. The opposite response has been found during La Niña. Interestingly, CP El Niño has no significant impact on extratropical TCO, while its signal in the tropics is weaker than for EP El Niño events. The analysis of mechanisms reveals that advection through changes in tropical upwelling is the main driver for ozone variations in the lower tropical stratosphere, with a contribution of chemical processes above 30hPa. At middle and high latitudes, stratospheric ozone variations related to ENSO result from combined changes in advection by residual circulation downwelling and changes in horizontal mixing linked to Rossby wave breaking and polar vortex anomalies. The impact of CP El Niño onthe shallow branch of the residual circulation is small, and no significant impact is found on the deep branch.
PB Copernicus Gesellschaft MBH
SN 1680-7316
YR 2022
FD 2022
LK https://hdl.handle.net/20.500.14352/72941
UL https://hdl.handle.net/20.500.14352/72941
LA eng
NO Benito-Barca, S., Calvo, N., and Abalos, M.: Driving mechanisms for the El Niño–Southern Oscillation impact on stratospheric ozone, Atmos. Chem. Phys., 22, 15729–15745, https://doi.org/10.5194/acp-22-15729-2022, 2022.
NO © Author(s) 2022. We are thankful to John Albers and Peter Braesicke for their very constructive comments. Samuel Benito Barca acknowledges the FPU program from the Ministry of Universities (grant no. FPU19/01481). Natalia Calvo was supported by the Spanish Ministry of Science, Innovation and Universities through the JeDiS project (no. RTI2018-096402-B-I00).
NO Ministerio de Universidades (España)
NO Ministerio de Ciencia, Innovación y Universidades (España)
DS Docta Complutense
RD 7 oct 2024