A nonstationary ENSO-NAO relationship due to AMO modulation
Many previous studies have demonstrated a high uncertainty in the relationship between the El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). In the present work, decadal modulation by the Atlantic Multidecadal Oscillation (AMO) is investigated as a possible cause of the nonst...
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ftunivreading:oai:centaur.reading.ac.uk:77663 2024-06-23T07:54:58+00:00 A nonstationary ENSO-NAO relationship due to AMO modulation Zhang, Wenjun Mei, Xuebin Geng, Xin Turner, Andrew G. Jin, Fei-Fei 2019-01 text https://centaur.reading.ac.uk/77663/ https://centaur.reading.ac.uk/77663/1/Zhangetal2018_jclim_accepted.pdf en eng American Meteorological Society https://centaur.reading.ac.uk/77663/1/Zhangetal2018_jclim_accepted.pdf Zhang, W., Mei, X., Geng, X., Turner, A. G. <https://centaur.reading.ac.uk/view/creators/90000510.html> orcid:0000-0002-0642-6876 and Jin, F.-F. (2019) A nonstationary ENSO-NAO relationship due to AMO modulation. Journal of Climate, 32. pp. 33-43. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-18-0365.1 <https://doi.org/10.1175/JCLI-D-18-0365.1> Article PeerReviewed 2019 ftunivreading https://doi.org/10.1175/JCLI-D-18-0365.1 2024-06-11T15:07:33Z Many previous studies have demonstrated a high uncertainty in the relationship between the El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). In the present work, decadal modulation by the Atlantic Multidecadal Oscillation (AMO) is investigated as a possible cause of the nonstationary ENSO-NAO relationship based on observed and reanalysis data. It is found that the negative ENSO-NAO correlation in late winter is significant only when ENSO and the AMO are in-phase (AMO+/El Niño and AMO-/La Niña). However, no significant ENSO-driven atmospheric anomalies can be observed over the North Atlantic when ENSO and the AMO are out-of-phase (AMO-/El Niño and AMO+/La Niña). Further analysis indicates that the sea surface temperature anomaly (SSTA) in the tropical North Atlantic (TNA) plays an essential role in this modulating effect. Due to broadly analogous TNA SSTA responses to both ENSO and the AMO during late winter, a warm SSTA in the TNA is evident when El Niño occurs during a positive AMO phase, resulting in a significantly weakened NAO, and vice versa when La Niña occur during a negative AMO phase. In contrast, neither the TNA SSTA nor the NAO show a prominent change under out-of-phase combinations of ENSO and AMO. The AMO modulation and associated effect of the TNA SSTA are shown to be well reproduced by historical simulations of the HadCM3 coupled model and further verified by forced experiments using an atmospheric circulation model. These offer hope that similar models will be able to make predictions for the NAO when appropriately initialized. Article in Journal/Newspaper North Atlantic North Atlantic oscillation CentAUR: Central Archive at the University of Reading Journal of Climate 32 1 33 43 |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
English |
description |
Many previous studies have demonstrated a high uncertainty in the relationship between the El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). In the present work, decadal modulation by the Atlantic Multidecadal Oscillation (AMO) is investigated as a possible cause of the nonstationary ENSO-NAO relationship based on observed and reanalysis data. It is found that the negative ENSO-NAO correlation in late winter is significant only when ENSO and the AMO are in-phase (AMO+/El Niño and AMO-/La Niña). However, no significant ENSO-driven atmospheric anomalies can be observed over the North Atlantic when ENSO and the AMO are out-of-phase (AMO-/El Niño and AMO+/La Niña). Further analysis indicates that the sea surface temperature anomaly (SSTA) in the tropical North Atlantic (TNA) plays an essential role in this modulating effect. Due to broadly analogous TNA SSTA responses to both ENSO and the AMO during late winter, a warm SSTA in the TNA is evident when El Niño occurs during a positive AMO phase, resulting in a significantly weakened NAO, and vice versa when La Niña occur during a negative AMO phase. In contrast, neither the TNA SSTA nor the NAO show a prominent change under out-of-phase combinations of ENSO and AMO. The AMO modulation and associated effect of the TNA SSTA are shown to be well reproduced by historical simulations of the HadCM3 coupled model and further verified by forced experiments using an atmospheric circulation model. These offer hope that similar models will be able to make predictions for the NAO when appropriately initialized. |
format |
Article in Journal/Newspaper |
author |
Zhang, Wenjun Mei, Xuebin Geng, Xin Turner, Andrew G. Jin, Fei-Fei |
spellingShingle |
Zhang, Wenjun Mei, Xuebin Geng, Xin Turner, Andrew G. Jin, Fei-Fei A nonstationary ENSO-NAO relationship due to AMO modulation |
author_facet |
Zhang, Wenjun Mei, Xuebin Geng, Xin Turner, Andrew G. Jin, Fei-Fei |
author_sort |
Zhang, Wenjun |
title |
A nonstationary ENSO-NAO relationship due to AMO modulation |
title_short |
A nonstationary ENSO-NAO relationship due to AMO modulation |
title_full |
A nonstationary ENSO-NAO relationship due to AMO modulation |
title_fullStr |
A nonstationary ENSO-NAO relationship due to AMO modulation |
title_full_unstemmed |
A nonstationary ENSO-NAO relationship due to AMO modulation |
title_sort |
nonstationary enso-nao relationship due to amo modulation |
publisher |
American Meteorological Society |
publishDate |
2019 |
url |
https://centaur.reading.ac.uk/77663/ https://centaur.reading.ac.uk/77663/1/Zhangetal2018_jclim_accepted.pdf |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
https://centaur.reading.ac.uk/77663/1/Zhangetal2018_jclim_accepted.pdf Zhang, W., Mei, X., Geng, X., Turner, A. G. <https://centaur.reading.ac.uk/view/creators/90000510.html> orcid:0000-0002-0642-6876 and Jin, F.-F. (2019) A nonstationary ENSO-NAO relationship due to AMO modulation. Journal of Climate, 32. pp. 33-43. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-18-0365.1 <https://doi.org/10.1175/JCLI-D-18-0365.1> |
op_doi |
https://doi.org/10.1175/JCLI-D-18-0365.1 |
container_title |
Journal of Climate |
container_volume |
32 |
container_issue |
1 |
container_start_page |
33 |
op_container_end_page |
43 |
_version_ |
1802647334648020992 |