A 150-year reconstructed summer Asian-Pacific Oscillation index and its association with precipitation over eastern China

作者：Liu Ge; Zhao Ping^*; Chen Junming

来源：Theoretical and Applied Climatology, 2011, 103(1-2): 239-248.

DOI：10.1007/s00704-010-0294-7

Reconstructing the long-term series of the East Asian summer monsoon (EASM) indices may help understand long-term variability of EASM and its associations with precipitation. In this study, the summer middle-upper tropospheric temperature over the Asian-North Pacific sector is reconstructed from sea level pressure during the past 150 years, and then an atmospheric thermal contrast between Asia and the North Pacific, called the Asian-Pacific Oscillation (APO) index, is calculated from the reconstructed temperature. The results show that the APO phenomenon may occur in the reconstructed temperature fields, and its index has a significant positive/negative correlation with SST over the extratropical North Pacific/the tropical central-eastern Pacific in the past 150 years. The reconstructed summer APO index shows inter-decadal variability, with a positive phase in the 1870-1890s, the 1920s, and the 1940-1970s, indicating a stronger thermal contrast between Asia and the North Pacific, and with a negative phase in the 1860s, the 1900-1910s, and the 1980-1990s, indicating a weaker thermal contrast. Corresponding to a higher APO index in earlier decades of the twentieth century, there are more rainfall to the south of the Yangtze River and over North China and less rainfall over the Huaihe River valley. In the recent decades, however, more- and less-rain belts shifted southwards when the APO index is higher. During 1850-1900, the reconstructed APO index also showed a significant positive correlation with precipitation in some regions of North China.

• 出版日期2011-1
• 单位国家气象信息中心