The southern oscillation, Equatorial Pacific anomalies and El Niño

Certain pressure indices (differences in sea level atmospheric pressure be tween Easter Island and Darwin, Australia and between Juan Fernández Island and Darwin), plotted as 12-month running mean values, were previously used for characterizing the Southern Oscillation and for monitoring and predict...

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Authors: Quinn, William H., Zopf, David O.
Format: article
Status:Published version
Publication Date:1975
Country:México
Institution:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repository:Geofísica Internacional
Language:Spanish
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/1513
Online Access:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1513
Access Level:Open access
Keyword:Índices de presión
Oscilación del sur
Anomalías
Pacífico Ecuatorial
Fenómeno El Niño
Pressure indices
Southern Oscillation
Anomalies
Equatorial Pacific
El Niño phenomenon
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oai_identifier_str oai:revistagi.geofisica.unam.mx:article/1513
network_acronym_str MX
network_name_str México
repository_id_str
dc.title.none.fl_str_mv The southern oscillation, Equatorial Pacific anomalies and El Niño
The southern oscillation, Equatorial Pacific anomalies and El Niño
title The southern oscillation, Equatorial Pacific anomalies and El Niño
spellingShingle The southern oscillation, Equatorial Pacific anomalies and El Niño
Quinn, William H.
Índices de presión
Oscilación del sur
Anomalías
Pacífico Ecuatorial
Fenómeno El Niño
Pressure indices
Southern Oscillation
Anomalies
Equatorial Pacific
El Niño phenomenon
title_short The southern oscillation, Equatorial Pacific anomalies and El Niño
title_full The southern oscillation, Equatorial Pacific anomalies and El Niño
title_fullStr The southern oscillation, Equatorial Pacific anomalies and El Niño
title_full_unstemmed The southern oscillation, Equatorial Pacific anomalies and El Niño
title_sort The southern oscillation, Equatorial Pacific anomalies and El Niño
dc.creator.none.fl_str_mv Quinn, William H.
Zopf, David O.
author Quinn, William H.
author_facet Quinn, William H.
Zopf, David O.
author_role author
author2 Zopf, David O.
author2_role author
dc.subject.none.fl_str_mv Índices de presión
Oscilación del sur
Anomalías
Pacífico Ecuatorial
Fenómeno El Niño
Pressure indices
Southern Oscillation
Anomalies
Equatorial Pacific
El Niño phenomenon
topic Índices de presión
Oscilación del sur
Anomalías
Pacífico Ecuatorial
Fenómeno El Niño
Pressure indices
Southern Oscillation
Anomalies
Equatorial Pacific
El Niño phenomenon
description Certain pressure indices (differences in sea level atmospheric pressure be tween Easter Island and Darwin, Australia and between Juan Fernández Island and Darwin), plotted as 12-month running mean values, were previously used for characterizing the Southern Oscillation and for monitoring and predicting significant equatorial Pacific ocean/atmosphere changes, including El Niño occurrences. The value of using additional pressure indices for these purposes is explored here. Since the primary interest was in changes over the Pacific, Darwin was used to represent the Indonesian equatorial low pressure center, but additional sites (Totegegie, Rapa and Tahiti) were used along the South Pacific subtropical ridge. In general, there is remarkable consistency between the trends of the various indices; however, on some occasions inflection points can be noted several months earlier when using one ridge site rather than another, and the amplitude of peaks and troughs in the indices is often much greater when using a particular ridge site. Three- and 6-month running means of the indices, which retain the regular annual cycle as well as the irregular interannual fluctuation, are used here to show the importance of phase relations between the two fluctuations in determining the intensity of anomalous developments. In the case of the unusual 1972 El Niño, the peaks of the two fluctuations were in phase in early 1971 and their troughs were in phase in mid-I972 so that a 14 mb drop in the 3-month running mean value of the Faster-Darwin index took place over an 18-month period. This indicated an extreme weakening of the southeast trade wind system, which we believe to be a causal factor for the severe 1972 event. In the subsequent 1975 event, the Southern Oscillation period shortened, and although the peaks of the two fluctuations were in phase the troughs were not; hence the degree of relaxation was limited and a weak event resulted. Additional evidence is presented to support a close relationship between the southeast trade system, as modified by the Southern Oscillation, and anomalous meteorological and oceanographic conditions in the equatorial Pacific.
publishDate 1975
dc.date.none.fl_str_mv 1975-10-01
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1513
10.22201/igeof.00167169p.1975.15.4.1011
url http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1513
identifier_str_mv 10.22201/igeof.00167169p.1975.15.4.1011
dc.language.none.fl_str_mv spa
language spa
dc.relation.none.fl_str_mv http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1513/1633
dc.rights.none.fl_str_mv Derechos de autor 1975 Geofísica Internacional
https://creativecommons.org/licenses/by-nc-sa/4.0/
info:eu-repo/semantics/openAccess
rights_invalid_str_mv Derechos de autor 1975 Geofísica Internacional
https://creativecommons.org/licenses/by-nc-sa/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Universidad Nacional Autónoma de México. Instituto de Geofísica
publisher.none.fl_str_mv Universidad Nacional Autónoma de México. Instituto de Geofísica
dc.source.none.fl_str_mv Geofisica Internacional; Vol. 15 No. 4 (1975): October 1, 1975; 327-353
Geofísica Internacional; Vol. 15 Núm. 4 (1975): Octubre 1, 1975; 327-353
2954-436X
0016-7169
reponame:Geofísica Internacional
instname:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
instacron:UNAM
instname_str UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
instacron_str UNAM
institution UNAM
reponame_str Geofísica Internacional
collection Geofísica Internacional
repository.name.fl_str_mv
repository.mail.fl_str_mv
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spelling The southern oscillation, Equatorial Pacific anomalies and El NiñoThe southern oscillation, Equatorial Pacific anomalies and El NiñoQuinn, William H.Zopf, David O.Índices de presiónOscilación del surAnomalíasPacífico EcuatorialFenómeno El NiñoPressure indicesSouthern OscillationAnomaliesEquatorial PacificEl Niño phenomenonCertain pressure indices (differences in sea level atmospheric pressure be tween Easter Island and Darwin, Australia and between Juan Fernández Island and Darwin), plotted as 12-month running mean values, were previously used for characterizing the Southern Oscillation and for monitoring and predicting significant equatorial Pacific ocean/atmosphere changes, including El Niño occurrences. The value of using additional pressure indices for these purposes is explored here. Since the primary interest was in changes over the Pacific, Darwin was used to represent the Indonesian equatorial low pressure center, but additional sites (Totegegie, Rapa and Tahiti) were used along the South Pacific subtropical ridge. In general, there is remarkable consistency between the trends of the various indices; however, on some occasions inflection points can be noted several months earlier when using one ridge site rather than another, and the amplitude of peaks and troughs in the indices is often much greater when using a particular ridge site. Three- and 6-month running means of the indices, which retain the regular annual cycle as well as the irregular interannual fluctuation, are used here to show the importance of phase relations between the two fluctuations in determining the intensity of anomalous developments. In the case of the unusual 1972 El Niño, the peaks of the two fluctuations were in phase in early 1971 and their troughs were in phase in mid-I972 so that a 14 mb drop in the 3-month running mean value of the Faster-Darwin index took place over an 18-month period. This indicated an extreme weakening of the southeast trade wind system, which we believe to be a causal factor for the severe 1972 event. In the subsequent 1975 event, the Southern Oscillation period shortened, and although the peaks of the two fluctuations were in phase the troughs were not; hence the degree of relaxation was limited and a weak event resulted. Additional evidence is presented to support a close relationship between the southeast trade system, as modified by the Southern Oscillation, and anomalous meteorological and oceanographic conditions in the equatorial Pacific.Ciertos índices de presión (diferencias en presión atmosférica a nivel del mar entre Easter Island y Darwin, Australia y entre la Isla Juan Fernández y Darwin) delineados como promedios consecutivos de 12 meses, fueron previamente utilizados para caracterizar la oscilación del sur y para monitorear y predecir cambios significativos oceánicos-atmosféricos en el Pacifico Ecuatorial, incluyendo las ocurrencias de El Niño. El valor de utilizar índices de presión adicionales para estos propósitos se explora aquí. Ya que el interés primario son los cambios sobre el Pacífico, Darwin se usa para representar el centro ecuatorial indonesio de baja presión, pero localidades adicionales (Totegegie, Rapa y Tahiti) se usaron a lo largo de la cresta subtropical del Pacifico Sur. En general, hay una consistencia marcada entre las tendencias de los diversos índices; sin embargo, en algunas ocasiones, los puntos de inflexión pueden ser apreciados con varios meses de anticipación cuando se usa una posición de la cresta en lugar de otra y la amplitud de los picos y vaguadas en los índices es a menudo mucho mayor cuando se usa un sitio particular de la cresta. Promedios consecutivos de 3 y 6 meses de los índices que retienen tanto el ciclo anual regular como la fluctuación irregular interanual, son usados aquí para mostrar la importancia de relaciones de fase entre estas 2 fluctuaciones en la determinación de la intensidad de desarrollos anómalos. En el caso poco común de El Niño en 1972, los picos de las 2 fluctuaciones estaban en fase al inicio de 1971 y sus vaguadas estaban en fase a mediados de 1972, de modo que una caída de 14 mb en los promedios consecutivos de 3 meses del índice Darwin oriental, ocurrió sobre un periodo de 18 meses. Esto indica un marcado debilitamiento del sistema de vientos alisios del sureste, que nosotros creemos que es un factor causal del evento severo de 1972. En el evento subsecuente de 1975, el periodo de la oscilación austral se acortó, y aunque las cimas de las 2 fluctuaciones estaban en fase, las vaguadas no lo estaban; por consiguiente, el grado de relajación estaba limitado y resultó un evento débil. Se presenta evidencia adicional para apoyar una relación estrecha entre el sistema de alisios del sureste, modificado por la oscilación austral, y las condiciones anómalas oceanográficas y meteorológicas en el Pacífico ecuatorial.Universidad Nacional Autónoma de México. Instituto de Geofísica1975-10-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttp://revistagi.geofisica.unam.mx/index.php/RGI/article/view/151310.22201/igeof.00167169p.1975.15.4.1011Geofisica Internacional; Vol. 15 No. 4 (1975): October 1, 1975; 327-353Geofísica Internacional; Vol. 15 Núm. 4 (1975): Octubre 1, 1975; 327-3532954-436X0016-7169reponame:Geofísica Internacionalinstname:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICOinstacron:UNAMspahttp://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1513/1633Derechos de autor 1975 Geofísica Internacionalhttps://creativecommons.org/licenses/by-nc-sa/4.0/info:eu-repo/semantics/openAccessoai:revistagi.geofisica.unam.mx:article/15132024-08-16T17:32:11Z
score 15,198674

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