Effect of Tibetan Plateau heating on summer extreme precipitation in eastern China
Effect of Tibetan Plateau heating on summer extreme precipitation in eastern China
复制标题
青藏高原升温对中国东部夏季极端降水的影响
DOI：
10.1016/j.atmosres.2018.12.018
复制
发表时间：
2019-04-01
影响因子：
5.5
通讯作者：
Zhang, Yuqing
中科院分区：
文献类型：
--
作者：
Ge, Jing;You, Qinglong;Zhang, Yuqing
青藏高原(TP)加热与中国东部夏季极端降水的关系尚不清楚。研究表明，当总磷加热偏强(弱)时，长江中下游地区夏季极端降水偏多(偏少)。通过研究高空南亚高压的影响，揭示了影响中国东部夏季极端降水与总磷加热的可能机制。结果表明，当对流层加热较强时，对流层下部TP区出现正涡度异常，对流层上部TP区出现负涡度异常并伴随上升运动异常，从而导致SAH加强并向东扩展。结果表明，南方涛动异常的东南部发生高层辐合和下沉运动，并在对流层中下层辐散，形成从中国南部到中国南海北部的异常负涡度。随后，西太平洋副热带高压(WPSH)加强并向西伸展。因此，长江中下游地区西南水汽输送和水汽辐合增强，导致极端降水增多。降水加热的垂直不均匀分布维持了SAH的东延和WPSH的西延。
The relationship between the Tibetan Plateau (TP) heating and summer extreme precipitation in eastern China is still unclear. This study shows that when the TP heating is stronger (weaker) than normal, summer extreme precipitation tends to be more (less) over the middle and lower reaches of the Yangtze River valley. The possible mechanisms responsible for the relationship between the TP heating and summer extreme precipitation in eastern China are revealed by investigating the effects of the upper-level South Asian High (SAH). It is found that positive and negative vorticity anomalies accompanied by an ascending motion anomaly occur over the TP regions in the lower and upper troposphere, respectively, when the TP heating is stronger, resulting in the strengthening and eastward extension of the SAH. As a result, an anomalous high-level convergence and downward movement occur over the southeastern portion of the SAH, which then diverge in the mid-lower troposphere, resulting in the formation of an anomalous negative vorticity from South China to the northern part of the South China Sea. Subsequently, the western Pacific subtropical high (WPSH) intensifies and stretches westward. Consequently, the southwestern moisture transport and moisture convergence increase over the middle and lower reaches of the Yangtze River valley, resulting in more extreme precipitation. The eastward extension of the SAH and westward stretching of the WPSH are maintained by the vertically inhomogeneous distribution of precipitation heating.