Impact of the Atlantic Multidecadal Oscillation on the Pacific North Equatorial Current bifurcation

Chau Ron Wu, Yong Fu Lin, Bo Qiu

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Variability in surface currents is mainly induced by the time-varying wind forcing. Recent studies have revealed robust pronounced changes in the atmospheric circulation over the Pacific came with the Pacific Decadal Oscillation (PDO). However, the PDO is a climate index based on sea surface temperature (SST) variations, and may not be appropriately considered as a climate forcing. Here, we suggest the Atlantic SST variability is the ultimate forcing leading to changes in the atmospheric circulation and surface winds over the North Pacific. Anomalous warm North Atlantic and cold South Atlantic leads to weak Hadley cell in the Northern Hemisphere, resulting in a northward displacement of the ITCZ as well as a positive wind stress curl anomaly in the Pacific subtropical region, which would reduce the North Pacific subtropical gyre (NPSG). Associated with reduced sea surface height in the subtropics by the weakened NPSG, the North Equatorial Current (NEC) is weakened based on geostrophy. Changes in basin-scale winds further result in the southward migration of the tropical gyre and consequential downstream ocean circulation.

Original languageEnglish
Article number2162
JournalScientific Reports
Volume9
Issue number1
DOIs
Publication statusPublished - 2019 Dec 1

    Fingerprint

ASJC Scopus subject areas

  • General

Cite this