Decadal Variation of the East Asian Winter Monsoon and Pacific Decadal Oscillation

  • Author(s): Pei-ken Kao, Chih-wen Hung, and Huang-Hsiung Hsu
  • DOI:

    10.3319/TAO.2016.05.29.01

  • Keywords: East Asian winter monsoon, Aleutian Low, Pacific Decadal Oscillation
  • Citation: Kao, P., C. Hung, and H. H. Hsu, 2016: Decadal variation of the East Asian Winter Monsoon and Pacific Decadal Oscillation. Terr. Atmos. Ocean. Sci., 27, 617-624, doi: 10.3319/TAO.2016.05.29.01
  • East Asian Winter Monsoon is related to the PDO
  • The Aleutian low moves westward in negative PDO phase
  • The northerly wind will be enhanced in negative PDO phase
Abstract

This study finds that the winter (December - February) decadal variability of northerly winds in the East Asian Winter Monsoon (EAWM) over the northern part of the East Asia Coast were influenced by forcing from the middle latitudes from the 1950s to 2000s and related to the Pacific Decadal Oscillation (PDO). We propose that the decreased EAWM in recent decades is associated with the change in pressure gradient along the East Asia coast. This mechanism accounts for the change of westward sea-level pressure (SLP) gradient along the Northeast Asia coast, and is affected by the Aleutian Low location, which is associated with the PDO phases. As the Aleutian Low is influenced by the negative PDO phase and moves westward, the SLP gradient between the Siberian High and the Aleutian Low can increase and the northerly wind at 850 hPa will be enhanced. This change is associated with the increased EAWM near Sakhalin Island of Russia to Hokkaido of Japan.

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