Abstract
The El Niño–Southern Oscillation (ENSO) in the tropical Pacific Ocean is of key importance to global climate and weather. However, state‐of‐the‐art climate models still disagree on the ENSO's response under climate change. The potential role of atmospheric ozone changes in this context has not been explored before. Here we show that differences between typical model representations of ozone can have a first‐order impact on ENSO amplitude projections in climate sensitivity simulations. The vertical temperature gradient of the tropical middle‐to‐upper troposphere adjusts to ozone changes in the upper troposphere and lower stratosphere, modifying the Walker circulation and consequently tropical Pacific surface temperature gradients. We show that neglecting ozone changes thus results in a significant increase in the number of extreme ENSO events in our model. Climate modeling studies of the ENSO often neglect changes in ozone. We therefore highlight the need to understand better the coupling between ozone, the tropospheric circulation, and climate variability.
Highlights
The El Niño–Southern Oscillation (ENSO) is an atmosphere-ocean coupled climate mode in the tropical Pacific with an irregular period of ~2–7 years [McPhaden et al, 2006; Guilyardi et al, 2009]
The use of preindustrial (i.e., CO2-level consistent) ozone in the noninteractive piControl simulations A1/A2 leads to no significant difference in ENSO amplitudes relative to A (Table 1 and Figure S1)
The Walker circulation is intrinsically coupled to the ENSO so that the changes in ozone eventually lead to adaptations in the tropical Pacific mean state (SST gradients and land-sea temperature contrasts) that tend to reduce amplitudes of ENSO events
Summary
The El Niño–Southern Oscillation (ENSO) is an atmosphere-ocean coupled climate mode in the tropical Pacific with an irregular period of ~2–7 years [McPhaden et al, 2006; Guilyardi et al, 2009]. It is characterized by positive or negative sea surface temperature (SST) anomalies in the East Pacific and Central Pacific. We demonstrate for the first time the potential of ozone changes to alter the response of the tropical Walker circulation and the ENSO to increased atmospheric carbon dioxide (CO2) concentrations
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
