Modulation of the northern winter stratospheric El Niño–Southern Oscillation teleconnection by the PDO

R. A.O. Jian*, Chaim I. Garfinkel, R. E.N. Rongcai

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Using the CMIP5 multimodel ensemble (MME) historical experiments, the modulation of the stratospheric El Niño–Southern Oscillation (ENSO) teleconnection by the Pacific decadal oscillation (PDO) is investigated in this study. El Niño (La Niña) significantly impacts the extratropical stratosphere mainly during the positive (negative) PDO in the MME. Although the composite tropical ENSO SST intensities are similar during the positive and negative PDO in models, the Pacific–North American (PNA) responses are only significant when the PDO and ENSO are in phase. The local SST anomalies in the North Pacific can constructively (destructively) interfere with the tropical ENSO forcing to influence the extratropical eddy height anomalies when the PDO and ENSO are in (out of) phase. The difference between the positive and negative PDO in El Niño or La Niña winters filters out the tropical SST forcing, permitting the deduction of the extratropical SST contribution to the atmospheric response. The composite shows that the cold (warm) SST anomalies in the central North Pacific associated with the positive (negative) PDO have a similar impact to that of the warm (cold) SST anomalies in the tropical Pacific, exhibiting a positive (negative) PNA-like response, enhancing (weakening) the upward propagation of waves over the western coast of North America. The composite difference between the positive and negative PDO in El Niño or La Niña winters, as well as in eastern Pacific ENSO or central Pacific ENSO winters, presents a highly consistent atmospheric response pattern, which may imply a linear interference of the PDO’s impact with ENSO’s.

Original languageAmerican English
Pages (from-to)5761-5783
Number of pages23
JournalJournal of Climate
Volume32
Issue number18
DOIs
StatePublished - 1 Sep 2019

Bibliographical note

Publisher Copyright:
© 2019 American Meteorological Society.

Fingerprint

Dive into the research topics of 'Modulation of the northern winter stratospheric El Niño–Southern Oscillation teleconnection by the PDO'. Together they form a unique fingerprint.

Cite this