Interannual covariability of summer monsoon precipitation in Yunnan, China, and diabatic heating anomalies over the Arabian Sea–Bay of Bengal
Interannual covariability of summer monsoon precipitation in Yunnan, China, and diabatic heating anomalies over the Arabian Sea–Bay of Bengal
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DOI：
10.1007/s00382-021-05794-w
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发表时间：
2021-05
期刊：
影响因子：
4.6
通讯作者：
Yingmo Zhu;Di Zhao;Qin Su;Ruowen Yang
中科院分区：
文献类型：
--
作者：
Yingmo Zhu;Di Zhao;Qin Su;Ruowen Yang
利用ERA-Interim月度再分析数据和中国云南124个站点的月平均降水数据，分析了云南夏季风降水与阿拉伯海-孟加拉湾非绝热加热异常（AS-BOB）的协变性。奇异值分解分析表明年际时间尺度上与AS-BOB非绝热加热和云南夏季风降水相关的跷跷板模式。当AS-BOB非绝热加热弱（强）于夏季风季节气候时，云南夏季风降水一般偏多（少）。 AS-BOB的非绝热加热与云南夏季风降水之间的显着相关性始于春末夏初，并持续整个夏季。因此，春末夏初的AS-BOB非绝热加热可能对云南夏季风降水具有预测潜力。与AS-BOB非绝热加热异常相关的异常低空风影响印度夏季风槽、云南的垂直运动，进而影响夏季风降水。基于线性斜压模型的数值实验证实了观察诊断中揭示的关键物理过程。这些实验还表明，AS-BOB上空的非绝热加热对云南夏季风降水的影响大于云南周边非绝热加热对AS-BOB上空大气环流的影响。 AS-BOB上空的非绝热加热异常通过影响环流而导致了2010年、2011年和2013年云南的严重夏季干旱。
Covariability of summer monsoon precipitation in Yunnan and diabatic heating anomalies over the Arabian Sea–Bay of Bengal (AS–BOB) is analyzed using ERA-Interim monthly reanalysis data and monthly mean precipitation data from 124 stations across Yunnan, China. Singular value decomposition analysis indicates a seesaw pattern associated with the diabatic heating over the AS–BOB and summer monsoon precipitation in Yunnan over interannual timescales. When the diabatic heating over the AS–BOB is weaker (stronger) than the climatology during the summer monsoon season, more (less) summer monsoon precipitation generally occurs in Yunnan. A significant correlation between the diabatic heating over the AS–BOB and summer monsoon precipitation in Yunnan begins in late spring–early summer and persists throughout the summer. The AS–BOB diabatic heating in late spring–early summer may thus have a prediction potential for summer monsoon precipitation in Yunnan. The anomalous low-level winds associated with the diabatic heating anomalies over the AS–BOB influence the Indian summer monsoon trough, the vertical motion in Yunnan, and then the summer monsoon precipitation. Numerical experiments based on a linear baroclinic model confirm the key physical process revealed in the observational diagnosis. These experiments also indicate that the diabatic heating over the AS–BOB has a greater impact on summer monsoon precipitation in Yunnan than does diabatic heating around Yunnan on the atmospheric circulation over the AS–BOB. The diabatic heating anomalies over the AS–BOB contributed to the severe summer droughts in Yunnan in 2010, 2011, and 2013 by influencing the circulation.