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| Titel |
Role of Global Warming in recent Speedup of the Wintertime Pacific Walker Circulation |
| VerfasserIn |
Xiao-Feng Li, Jianping Li, Yun Li, Jingjing Yu, Hayley Fowler, Stephen Blenkinsop, Ruiqiang Ding, Sen Zhao, Fei Zheng, Juan Feng, Yanjie Li, Cheng Sun |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143222
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| Publikation (Nr.) |
 EGU/EGU2017-6926.pdf |
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| Zusammenfassung |
| The strengthening of the wintertime Pacific Walker Circulation (PWC) in the past 2-3
decades1−7 is in apparent contradiction to its century-scale weakening under global
warming8−10. Although there are several proposed mechanisms, the contribution of global
warming to this speedup is still unclear3,11,12. We analyse global SSTs and find the first two
EOF modes, a global warming mode (GWM) and an ENSO-like mode (ELM)13, account for
over 73% (±17%) of the PWC’s post-1976 strengthening trend in winter, its mature phase.
We find the GWM weakens the PWC, but the ELM enhances it by over twice as much, with a
ratio of -0.37(±0.08):1(±0.23). We further use an atmosphere-only general circulation model
to demonstrate the contrasting effects of the GLM and ELM in modulating the PWC. We
conclude that global warming is weakening the PWC through the GWM but both
modes are needed to resolve the apparent contradiction of recent observations. |
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