Interannual Variability of East Asian Summer Monsoon Simulated by CMIP3 and CMIP5 AGCMs: Skill Dependence on Indian Ocean-Western Pacific Anticyclone Teleconnection
Interannual Variability of East Asian Summer Monsoon Simulated by CMIP3 and CMIP5 AGCMs: Skill Dependence on Indian Ocean-Western Pacific Anticyclone Teleconnection
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DOI：
10.1175/jcli-d-13-00248.1
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发表时间：
2014-02-01
影响因子：
4.9
通讯作者：
Zhou, Tianjun
中科院分区：
文献类型：
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作者：
Song, Fengfei;Zhou, Tianjun
利用耦合模式比对计划（CMIP 3）第三阶段的13个大气环流模式（AGCM）和CMIP 5的19个AGCM，对东亚夏季风的气候特征和年际变率进行了研究。CMIP 3和CMIP 5大气环流模式的多模式集合平均（MME）合理地再现了低层季风环流的平均值，除了西太平洋副热带高压的北移。然而，被称为梅雨/白乌/昌马（北纬28度至38度，东经105度至150度）的季风雨带模拟得很差，尽管从CMIP 3到CMIP 5有显著的改善。通过对降水和850 hPa风场对东亚夏季风指数的回归分析，得到了东亚夏季风的年际分布型。CMIP 3和CMIP 5 MME部分地再现了观测到的偶极雨型，但有两个不足之处：较弱的量级和偶极雨型的南移。这些不足与西太平洋反气旋（WPAC）的减弱和南移密切相关。从CMIP 3到CMIP 5 MME，对东亚夏季风年际分布型的模拟能力有了明显的提高，并伴随着偶极子型和WPAC的增强。分析表明，热带东印度洋（IO）降水对当地暖SST异常的响应和印度-西太平洋地区相关的开尔文波响应是重要的维持WPAC。东亚夏季风年际分布型的成功再现依赖于IO-WPAC遥相关。从CMIP 3到CMIP 5 MME的年际EASM模式的显着改善也是由于CMIP 5模式更好地再现了这种遥相关。
The climatology and interannual variability of East Asian summer monsoon (EASM) are investigated by using 13 atmospheric general circulation models (AGCMs) from phase 3 of the Coupled Model Intercomparison Project (CMIP3) and 19 AGCMs from CMIP5. The mean low-level monsoon circulation is reasonably reproduced in the multimodel ensemble mean (MME) of CMIP3 and CMIP5 AGCMs, except for a northward shift of the western Pacific subtropical high. However, the monsoon rainband known as mei-yu/baiu/changma (28 degrees-38 degrees N, 105 degrees-150 degrees E) is poorly simulated, although a significant improvement is seen from CMIP3 to CMIP5. The interannual EASM pattern is obtained by regressing the precipitation and 850-hPa wind on the observed EASM index. The observed dipole rainfall pattern is partly reproduced in CMIP3 and CMIP5 MME but with two deficiencies: weaker magnitude and southward shift of the dipole rainfall pattern. These deficiencies are closely related to the weaker and southward shift of the western Pacific anticyclone (WPAC). The simulation skill of the interannual EASM pattern has been significantly improved from CMIP3 to CMIP5 MME accompanied by the enhanced dipole rainfall pattern and WPAC. Analyses demonstrate that the tropical eastern Indian Ocean (IO) rainfall response to local warm SST anomalies and the associated Kelvin wave response over the Indo-western Pacific region are important to maintain the WPAC. A successful reproduction of interannual EASM pattern depends highly on the IO-WPAC teleconnection. The significant improvement in the interannual EASM pattern from CMIP3 to CMIP5 MME is also due to a better reproduction of this teleconnection in CMIP5 models.