Phase transition of the Pacific decadal oscillation and decadal variation of the East Asian summer monsoon in the 20th century
- 157 Downloads
This paper focuses on the relationship between the phase transition of the Pacific decadal oscillation (PDO) and decadal variation of the East Asian summer monsoon (EASM) in the twentieth century. The first transition occurred in the 1940s, with an enhanced SST in the North Pacific and reduced SST in the tropical eastern Pacific and South Indian Ocean. In agreement with these SST changes, a higher SLP was found in most parts of the Pacific, while a lower SLP was found in the North Pacific and most parts of the Indian Ocean. In this case, the EASM was largely enhanced with a southerly anomaly in the lower troposphere along the east coast of China. Correspondingly, there was less rainfall in the Yangtze River valley and more rainfall in northern and southern China. An opposite change was found when the PDO reversed its phase in the late 1970s. In the tropical Indian Ocean and western Pacific, however, the SST was enhanced in both the 1940s and 1970s. As a result, the western Pacific subtropical high (WPSH) tended to extend westward with a larger magnitude in the 1970s. The major features were reasonably reproduced by an atmospheric general circulation model (IAP AGCM4.0) prescribed with observed SST and sea ice. On the other hand, the westward extension of the WPSH was exaggerated in the 1970s, while it was underestimated in the 1940s. Besides, the spatial pattern of the simulated summer rainfall in eastern China tended to shift southward compared with the observation.
Key wordsPacific decadal oscillation East Asian summer monsoon western Pacific subtropical high IAP AGCM4.0
Unable to display preview. Download preview PDF.
- Chen, H., and F. Xue, 2013: Numerical simulation of decadal variations in the East Asian summer monsoon and summer rainfall in eastern China. Chinese J. Atmos. Sci., 37, 1143–1153. (in Chinese)Google Scholar
- Su, T. H., and F. Xue, 2010: The intraseasonal variation of summer monsoon circulation and rainfall in East Asia. Chinese J. Atmos. Sci., 34, 611–628. (in Chinese)Google Scholar
- Wen, X. Y., S. W. Wang, J. H. Zhu, and D. Viner, 2006: An overview of China climate change over the 20th century using UK UEA/CRU high resolution grid data. Chinese J. Atmos. Sci., 30(5), 894–904, doi: 10.3878/jissn.1006-9895.2006.05. 18. (in Chinese)Google Scholar
- Yang, X. Q., Q. Xie, Y. M. Zhu, X. G. Sun, and Y. J. Guo, 2005: Decadal-to-interdecadal variability of precipitation in north China and associated atmospheric and oceanic anomaly patterns. Chinese J. Geophys., 48, 789–797. (in Chinese)Google Scholar
- Zhang, H., Z. H. Lin, and Q. C. Zeng, 2009: The computational scheme and the test for dynamical framework of IAP AGCM-4. Chinese J. Atmos. Sci., 33, 1267–1285. (in Chinese)Google Scholar
- Zhou, T. J., D. Y. Gong, J. Li, and B. Li, 2009a: Detecting and understanding the multi-decadal variability of the East Asian summer monsoon-recent progress and state of affairs. Meteorologische Zeitschrift, 18, 455–467.Google Scholar
- Zhou, T. J., and Coauthors, 2009b: Why the western Pacific subtropical high has extended westward since the late 1970s. J. Climate, 22, 2199–2215.Google Scholar
- Zhu, Y. M., and X. Q. Yang, 2003: Relationships between Pacific decadal oscillation (PDO) and climate variabilities in China. Acta Meteor. Sinica, 61, 641–654. (in Chinese)Google Scholar
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.