Influence of the Pacific Decadal Oscillation on the Relationship between El Niño and the Northeast Asian Summer Monsoon
- 1 September 2010
- journal article
- Published by American Meteorological Society in Journal of Climate
- Vol. 23 (17), 4525-4537
- https://doi.org/10.1175/2010jcli3352.1
Abstract
The influence of the Pacific decadal oscillation (PDO) on the relationship between El Niño and the northeast Asian summer monsoon (NEASM) is examined using observational datasets for the period of 1979–2007. When El Niño occurs during the boreal winter (December–February), the amount of rainfall over northeast Asia is usually above normal during the following summer (June–August). This relationship between El Niño and the NEASM is intensified when El Niño and the PDO are in phase during the previous winter. However, when El Niño and the PDO are out of phase, the relationship is weakened. The authors argue that the PDO can constructively or destructively interfere with the summer rainfall response over northeast Asia to El Niño. They follow the hypothesis that the summer rainfall over northeast Asia could be separated into two components, that is, the tropics-related component and the extratropics-related component. Then they argue that the PDO could modulate the relationship between El Niño and the NEASM through changes in the extratropics-related rainfall, which is associated with the atmospheric circulation, such as the Eurasian pattern. The conditional composites show that when El Niño and the PDO are in phase, the Eurasian-like pattern acts to enhance the extratropics-related rainfall over northeast Asia, resulting in the strengthening of the NEASM. In contrast, the Eurasian-like pattern acts to reduce the extratropics-related rainfall when El Niño and the PDO are out of phase, resulting in the weakening of the NEASM.Keywords
This publication has 52 references indexed in Scilit:
- Interdecadal shift in the relationship between the East Asian summer monsoon and the tropical Indian OceanClimate Dynamics, 2009
- PDO, ENSO and the early summer monsoon rainfall over south ChinaGeophysical Research Letters, 2005
- East Asian MonsoonWorld Scientific Series on Asia-Pacific Weather and Climate, 2004
- ENSO, Pacific Decadal Variability, and U.S. Summertime Precipitation, Drought, and Stream FlowJournal of Climate, 2001
- Interannual and Interdecadal Variations of the East Asian Summer Monsoon and Tropical Pacific SSTs. Part II: Meridional Structure of the MonsoonJournal of Climate, 2000
- Empirical evidence for North Pacific regime shifts in 1977 and 1989Progress in Oceanography, 2000
- Interdecadal Modulation of ENSO TeleconnectionsBulletin of the American Meteorological Society, 1998
- A Mechanism for the Recurrence of Wintertime Midlatitude SST AnomaliesJournal of Physical Oceanography, 1995
- The Characteristics of Interannual Variations on the East Asian MonsoonJournal of the Meteorological Society of Japan. Ser. II, 1992
- Classification, Seasonality and Persistence of Low-Frequency Atmospheric Circulation PatternsMonthly Weather Review, 1987