Possible North Atlantic origin for changes in ENSO properties during the 1970s
The most intense El Niño episodes in more than a century occurred after the 1970s climate shift. Previous studies show that the characteristics of the El Niño-Southern Oscillation (ENSO) phenomenon changed synchronously with the shift, but the associated causes are not fully understood. An analysis...
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ftawi:oai:epic.awi.de:38055 2024-09-15T18:09:55+00:00 Possible North Atlantic origin for changes in ENSO properties during the 1970s Dima, Mihai Lohmann, Gerrit Rimbu, Norel 2015 https://epic.awi.de/id/eprint/38055/ https://doi.org/10.1007/s00382-014-2173-x https://hdl.handle.net/10013/epic.45602 unknown Dima, M. , Lohmann, G. orcid:0000-0003-2089-733X and Rimbu, N. orcid:0000-0003-2832-9396 (2015) Possible North Atlantic origin for changes in ENSO properties during the 1970s , Climate Dynamics, 44 (3-4), pp. 925-935 . doi:10.1007/s00382-014-2173-x <https://doi.org/10.1007/s00382-014-2173-x> , hdl:10013/epic.45602 EPIC3Climate Dynamics, 44(3-4), pp. 925-935, ISSN: 0930-7575 Article isiRev 2015 ftawi https://doi.org/10.1007/s00382-014-2173-x 2024-06-24T04:12:21Z The most intense El Niño episodes in more than a century occurred after the 1970s climate shift. Previous studies show that the characteristics of the El Niño-Southern Oscillation (ENSO) phenomenon changed synchronously with the shift, but the associated causes are not fully understood. An analysis of the observed tropical Pacific sea surface temperature (SST) anomalies shows that their increase in the eastern part of the basin after the 1970s is not related to the canonical ENSO pattern, but to the tropical Pacific meridional mode (TPMM). We present observational evidence which supports the hypothesis that the change in the TPMM was triggered by the great salinity anomaly (GSA), which manifested in the North Atlantic during the late 1960s. The GSA induced a weak Labrador convection and a SST dipole south of Greenland. The associated atmospheric structure includes a North Pacific Oscillation sea level pressure dipole in the Pacific sector. This excites the TPMM which contributes to the intense El Niño events and to the enhanced ENSO’s asymmetry, observed after the shift. Our results imply that, if the GSA has not an anthropic origin, as was suggested, then the tropical Pacific climate shift has a natural origin. This is supported by the end of the North Atlantic regime in the 1990s and by the rebound of the tropical Pacific after 1998. Article in Journal/Newspaper Greenland North Atlantic Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Climate Dynamics 44 3-4 925 935 |
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Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The most intense El Niño episodes in more than a century occurred after the 1970s climate shift. Previous studies show that the characteristics of the El Niño-Southern Oscillation (ENSO) phenomenon changed synchronously with the shift, but the associated causes are not fully understood. An analysis of the observed tropical Pacific sea surface temperature (SST) anomalies shows that their increase in the eastern part of the basin after the 1970s is not related to the canonical ENSO pattern, but to the tropical Pacific meridional mode (TPMM). We present observational evidence which supports the hypothesis that the change in the TPMM was triggered by the great salinity anomaly (GSA), which manifested in the North Atlantic during the late 1960s. The GSA induced a weak Labrador convection and a SST dipole south of Greenland. The associated atmospheric structure includes a North Pacific Oscillation sea level pressure dipole in the Pacific sector. This excites the TPMM which contributes to the intense El Niño events and to the enhanced ENSO’s asymmetry, observed after the shift. Our results imply that, if the GSA has not an anthropic origin, as was suggested, then the tropical Pacific climate shift has a natural origin. This is supported by the end of the North Atlantic regime in the 1990s and by the rebound of the tropical Pacific after 1998. |
format |
Article in Journal/Newspaper |
author |
Dima, Mihai Lohmann, Gerrit Rimbu, Norel |
spellingShingle |
Dima, Mihai Lohmann, Gerrit Rimbu, Norel Possible North Atlantic origin for changes in ENSO properties during the 1970s |
author_facet |
Dima, Mihai Lohmann, Gerrit Rimbu, Norel |
author_sort |
Dima, Mihai |
title |
Possible North Atlantic origin for changes in ENSO properties during the 1970s |
title_short |
Possible North Atlantic origin for changes in ENSO properties during the 1970s |
title_full |
Possible North Atlantic origin for changes in ENSO properties during the 1970s |
title_fullStr |
Possible North Atlantic origin for changes in ENSO properties during the 1970s |
title_full_unstemmed |
Possible North Atlantic origin for changes in ENSO properties during the 1970s |
title_sort |
possible north atlantic origin for changes in enso properties during the 1970s |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/38055/ https://doi.org/10.1007/s00382-014-2173-x https://hdl.handle.net/10013/epic.45602 |
genre |
Greenland North Atlantic |
genre_facet |
Greenland North Atlantic |
op_source |
EPIC3Climate Dynamics, 44(3-4), pp. 925-935, ISSN: 0930-7575 |
op_relation |
Dima, M. , Lohmann, G. orcid:0000-0003-2089-733X and Rimbu, N. orcid:0000-0003-2832-9396 (2015) Possible North Atlantic origin for changes in ENSO properties during the 1970s , Climate Dynamics, 44 (3-4), pp. 925-935 . doi:10.1007/s00382-014-2173-x <https://doi.org/10.1007/s00382-014-2173-x> , hdl:10013/epic.45602 |
op_doi |
https://doi.org/10.1007/s00382-014-2173-x |
container_title |
Climate Dynamics |
container_volume |
44 |
container_issue |
3-4 |
container_start_page |
925 |
op_container_end_page |
935 |
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1810447526059311104 |